Table of Radionuclides - BIPM · Table of Radionuclides ... 36Cl, 37Ar, 45Ca, 67Ga, ... These topics are described in detail in the chapter “Rules for evaluation and compilations”

Monographie BIPM-5

Table of Radionuclides (Comments on evaluation)

M.-M. B, V. CHIST, C. DULIEU, X. MOUGEOT

E. BROWNE, C. BAGLIN V.P. CHECHEV, A. EGOROV, N.K. KUZMENKO, V.O. SERGEEV

F.G. KONDEV A. LUCA

M. GALN X. HUANG, B. WANG

R.G. HELMER E. SCHNFELD, R. DERSCH

V.R. VANIN, R.M. de CASTRO A.L. NICHOLS

T.D. MACMAHON, A. PEARCE, A. ARINC K.B. LEE S.C. WU

Volumes 1-7, 2013

BUREAU INTERNATIONAL DES POIDS ET MESURES

Pavillon de Breteuil, F-92310 SVRES

dit par le BIPM, Pavillon de Breteuil F-92312 Svres Cedex France Imprim par Reproduction Service ISBN-13 978-92-822-2248-5 (Vol. 7) ISBN-13 978-92-822-2249-2 (CD-Rom)

TABLE DE RADIONUCLIDES TABLE OF RADIONUCLIDES

COMMENTS ON EVALUATIONS Marie-Martine B, Vanessa CHIST, Christophe DULIEU, Xavier MOUGEOT, Laboratoire National Henri Becquerel (LNHB), France; Valery CHECHEV, Khlopin Radium Institute (KRI), Russia; Filip G. KONDEV, Argonne National Laboratory (ANL), USA; Alan L. NICHOLS, Department of Physics, University of Surrey, United Kingdom; Xiaolong HUANG, Baosong WANG, China Institute of Atomic Energy (CIAE), China.

- 2013 -

Monographie BIPM-5 - Table of Radionuclides, Comments on evaluations, Volume 7 Marie-Martine B, Vanessa CHIST, Christophe DULIEU, Xavier MOUGEOT, Laboratoire National Henri Becquerel (LNHB), France; Valery CHECHEV, Khlopin Radium Institute (KRI), Russia; Filip G. KONDEV, Argonne National Laboratory (ANL), USA; Alan L. NICHOLS, Department of Physics, University of Surrey, United Kingdom; Xiaolong HUANG, Baosong WANG, China Institute of Atomic Energy (CIAE), China. Sommaire Depuis quelques annes, un groupe compos dvaluateurs spcialistes des donnes de dcroissance radioactive sest form, avec lobjectif de raliser une valuation soigneuse et documente de ces donnes pour des radionuclides intervenant dans de nombreuses applications. Ces valuateurs se sont mis daccord sur une mthodologie commune. Ce rapport inclut les commentaires sur les valuations des radionuclides figurant dans le rapport Monographie BIPM-5, volume 7 : 14C, 35S, 36Cl, 37Ar, 45Ca, 67Ga, 68Ga, 68Ge,127Sb, 127Te, 127mTe, 134Cs, 141Ce, 147Nd, 147Pm, 195Au, 206Hg, 207Tl, 208Tl, 209Tl, 211Pb, 211At, 213Bi, 215Bi, 228Th, 242Cm, 243Cm, 244Cm, 245Cm. Summary Over the past years, an informal collaboration of decay-data evaluators has been assembled with the goal of creating high-quality, well-documented evaluations of the decay data for a selected set of radionuclides that are of interest in various applications. This report includes, for each radionuclide, the evaluators comments on how the evaluation was carried out for the radionuclides that are in the Monographie BIPM-5, volume 7: 14C, 35S, 36Cl, 37Ar, 45Ca, 67Ga, 68Ga, 68Ge,127Sb, 127Te, 127mTe, 134Cs, 141Ce, 147Nd, 147Pm, 195Au, 206Hg, 207Tl, 208Tl, 209Tl, 211Pb, 211At, 213Bi, 215Bi, 228Th, 242Cm, 243Cm, 244Cm, 245Cm. Monographie BIPM-5 - Table of Radionuclides, Comments on evaluations, volumes 1 to 6 3H, 7Be, 11C, 13N, 15O, 18F, 22Na, 24Na, 32P, 33P, 40K, 41Ar, 44Sc, 44Ti, 46Sc, 51Cr, 54Mn, 55Fe, 56Mn, 56Co, 57Co, 57Ni, 59Fe, 59Ni, 60Co, 63Ni, 64Cu, 65Zn, 66Ga, 67Ga, 75Se, 79Se, 85Kr, 85Sr, 88Y, 89Sr, 90Sr, 90Y, 90mY, 93mNb, 99Mo, 99Tc, 99mTc, 108Ag, 108mAg, 109Pd, 109Cd, 110Ag, 110mAg, 111In, 123mTe, 123I, 124Sb, 125Sb, 125I, 129I, 131I, 131mXe, 132Te, 133I, 133Xe, 133mXe, 133Ba, 135mXe, 137Cs, 139Ce, 140Ba, 140La, 152Eu, 153Sm, 153Gd, 154Eu, 155Eu, 159Gd, 166Ho, 166mHo, 169Yb, 170Tm, 177Lu, 182Ta, 186Re, 198Au, 201Tl, 203Hg, 203Pb, 204Tl, 206Tl, 207Bi, 208Tl, 209Pb, 209Po, 210Tl, 210Pb, 210Bi, 210Po, 211Bi, 211Po, 212Pb, 212Bi, 212Po, 213Po, 214Pb, 214Bi, 214Po, 215Po, 215At, 216Po, 217At, 217Rn, 218Po, 218At, 218Rn, 219At, 219Rn, 220Rn, 221Fr, 222Rn, 223Fr, 223Ra, 224Ra, 225Ra, 225Ac, 226Ra, 227Ac, 227Th, 228Ra, 228Ac, 228Th, 231Th, 231Pa, 232Th, 232U, 233Th, 233Pa, 234Th, 234Pa, 234mPa, 234U, 235U, 236U, 236Np, 236mNp, 237U, 237Np, 238U, 238Np, 238Pu, 239U, 239Np, 239Pu, 240Pu, 241Pu, 241Am, 242Pu, 242Am, 242mAm, 242Cm, 243Am, 244Am, 244mAm, 244Cm, 246Cm, 252Cf.

III

TABLE DE RADIONUCLIDES COMMENTAIRES SUR LES VALUATIONS

De nombreuses applications ncessitent la connaissance des donnes lies la dsintgration des radionuclides, telles que la priode radioactive, les nergies et les intensits des divers rayonnements. Pour rpondre aux demandes des utilisateurs, le Laboratoire National Henri Becquerel (LNE - LNHB, France) a, de 1982 1987, publi une table en quatre volumes [87Ta, 99Be]. Puis, en 1993 une coopration a t tablie avec le Physikalisch-Technische Bundesanstalt (PTB, Allemagne) afin de reprendre cette tude et de la dvelopper. En 1995, un nouveau groupe de travail international nomm Decay Data Evaluation Project (DDEP) sest form qui, en plus des deux laboratoires nationaux prcdents, inclut : Idaho National Engineering and Environmental Laboratory (INEEL, USA), Lawrence Berkeley National Laboratory (LBNL, USA), Brookhaven National Laboratory (BNL, USA) et Khlopin Radium Institute (KRI, Russie).

Le propos de ce groupe est de fournir aux utilisateurs des donnes soigneusement values qui puissent servir de rfrence. A cette fin, tous les membres du groupe suivent une mthodologie commune qui comprend :

la lecture attentive de toutes les publications relatives une grandeur ; une analyse statistique des donnes retenues ; le choix et lutilisation des mmes jeux de donnes, pour celles ayant fait lobjet dtudes

spcifiques par des spcialistes, tels les coefficients de conversion interne.

Tous ces points sont dvelopps en dtail dans le chapitre Rules for evaluation and compilations .

Par ailleurs, toutes les valuations sont documentes et ltablissement des valeurs retenues explicit. Ce document est ensuite relu par deux membres du groupe.

Ce 7e volume regroupe les commentaires lis lvaluation des radionuclides suivants : 14C, 35S, 36Cl, 37Ar, 45Ca, 67Ga, 68Ga, 68Ge,127Sb, 127Te, 127mTe, 134Cs, 141Ce, 147Nd, 147Pm, 195Au, 206Hg, 207Tl, 208Tl, 209Tl, 211Pb, 211At, 213Bi, 215Bi, 228Th, 242Cm, 243Cm, 244Cm, 245Cm.

Ainsi que ceux prcdemment publis dans les volumes 1 6 : 3H, 7Be, 11C, 13N, 15O, 18F, 22Na, 24Na, 32P, 33P, 40K, 41Ar, 44Sc, 44Ti, 46Sc, 51Cr, 54Mn, 55Fe, 56Mn, 56Co, 57Co, 57Ni, 59Fe, 59Ni, 60Co, 63Ni, 64Cu, 65Zn, 66Ga, 67Ga, 75Se, 79Se, 85Kr, 85Sr, 88Y, 89Sr, 90Sr, 90Y, 90mY, 93mNb, 99Mo, 99Tc, 99mTc, 108Ag, 108mAg, 109Pd, 109Cd, 110Ag, 110mAg, 111In, 123mTe, 123I, 124Sb, 125Sb, 125I, 129I, 131I, 131mXe, 132Te, 133I, 133Xe, 133mXe, 133Ba, 135mXe, 137Cs, 139Ce, 140Ba, 140La, 152Eu, 153Sm, 153Gd, 154Eu, 155Eu, 159Gd, 166Ho, 166mHo, 169Yb, 170Tm, 177Lu, 182Ta, 186Re, 198Au, 201Tl, 203Hg, 203Pb, 204Tl, 206Tl, 207Bi, 208Tl, 209Pb, 209Po, 210Tl, 210Pb, 210Bi, 210Po, 211Bi, 211Po, 212Pb, 212Bi, 212Po, 213Po, 214Pb, 214Bi, 214Po, 215Po, 215At, 216Po, 217At, 217Rn, 218Po, 218At, 218Rn, 219At, 219Rn, 220Rn, 221Fr, 222Rn, 223Fr, 223Ra, 224Ra, 225Ra, 225Ac, 226Ra, 227Ac, 227Th, 228Ra, 228Ac, 228Th, 231Th, 231Pa, 232Th, 232U, 233Th, 233Pa, 234Th, 234Pa, 234mPa, 234U, 235U, 236U, 236Np, 236mNp, 237U, 237Np, 238U, 238Np, 238Pu, 239U, 239Np, 239Pu, 240Pu, 241Pu, 241Am, 242Pu, 242Am, 242mAm, 242Cm, 243Am, 244Am, 244mAm, 244Cm, 246Cm, 252Cf. Les donnes de dcroissance radioactive de ces radionuclides peuvent tre trouves dans la Monographie BIPM-5 de la Table de radionuclides , dans le CD-Rom NUCLIDE dit par le LNHB ou sur les pages web : http://www.nucleide.org/NucData.htm

V

TABLE OF RADIONUCLIDES COMMENTS ON EVALUATIONS Basic properties of radionuclides, such as half-life, decay mode and branchings, radiation energies and emission probabilities are commonly used in various research fields. To meet the demand for these data the LNHB produced a table that was published in four volumes [87Ta, 99Be] from 1982 to 1987. In 1993, a cooperative agreement was established between the Laboratoire National Henri Becquerel (LNE - LNHB, France) and the Physikalisch-Technische Bundesanstalt (PTB, Germany) to continue and expand this work. In 1995, a new international collaboration was formed, the Decay Data Evaluation Project (DDEP), which has the same objectives. Along with the evaluators from LNHB and PTB, this collaboration includes others from the Idaho National Engineering and Environmental Laboratory (INEEL, USA), the Lawrence Berkeley National Laboratory (LBNL, USA), the Brookhaven National Laboratory (BNL, USA) and the Khlopin Radium Institute (KRI, Russia). Its objective has been to provide carefully produced recommended values, which may eventually become standard data. With this goal in mind, the collaboration has adopted a uniform evaluation methodology that contains the following:

a critical review of relevant publications; an accounting of all measured data; a uniform statistical analysis of the data; a presentation of values for quantities such as internal conversion coefficients, etc.; a review of evaluation by two other members of the collaboration.

These topics are described in detail in the chapter Rules for evaluation and compilations.

The evaluation of each individual radionuclide has a section (presented here) that describes the procedures used for deducing the recommended values. This documentation is included in order to establish the quality and completeness of each evaluation. It can also provide the basis for any future reevaluation by the DDEP or other groups. This seventh volume contains the procedures and comments relevant to the evaluation for the following radionuclides: 14C, 35S, 36Cl, 37Ar, 45Ca, 67Ga, 68Ga, 68Ge,127Sb, 127Te, 127mTe, 134Cs, 141Ce, 147Nd, 147Pm, 195Au, 206Hg, 207Tl, 208Tl, 209Tl, 211Pb, 211At, 213Bi, 215Bi, 228Th, 242Cm, 243Cm, 244Cm, 245Cm. As well as those previously published in volumes 1 to 6: 3H, 7Be, 11C, 13N, 15O, 18F, 22Na, 24Na, 32P, 33P, 40K, 41Ar, 44Sc, 44Ti, 46Sc, 51Cr, 54Mn, 55Fe, 56Mn, 56Co, 57Co, 57Ni, 59Fe, 59Ni, 60Co, 63Ni, 64Cu, 65Zn, 66Ga, 67Ga, 75Se, 79Se, 85Kr, 85Sr, 88Y, 89Sr, 90Sr, 90Y, 90mY, 93mNb, 99Mo, 99Tc, 99mTc, 108Ag, 108mAg, 109Pd, 109Cd, 110Ag, 110mAg, 111In, 123mTe, 123I, 124Sb, 125Sb, 125I, 129I, 131I, 131mXe, 132Te, 133I, 133Xe, 133mXe, 133Ba, 135mXe, 137Cs, 139Ce, 140Ba, 140La, 152Eu, 153Sm, 153Gd, 154Eu, 155Eu, 159Gd, 166Ho, 166mHo, 169Yb, 170Tm, 177Lu, 182Ta, 186Re, 198Au, 201Tl, 203Hg, 203Pb, 204Tl, 206Tl, 207Bi, 208Tl, 209Pb, 209Po, 210Tl, 210Pb, 210Bi, 210Po, 211Bi, 211Po, 212Pb, 212Bi, 212Po, 213Po, 214Pb, 214Bi, 214Po, 215Po, 215At, 216Po, 217At, 217Rn, 218Po, 218At, 218Rn, 219At, 219Rn, 220Rn, 221Fr, 222Rn, 223Fr, 223Ra, 224Ra, 225Ra, 225Ac, 226Ra, 227Ac, 227Th, 228Ra, 228Ac, 228Th, 231Th, 231Pa, 232Th, 232U, 233Th, 233Pa, 234Th, 234Pa, 234mPa, 234U, 235U, 236U, 236Np, 236mNp, 237U, 237Np, 238U, 238Np, 238Pu, 239U, 239Np, 239Pu, 240Pu, 241Pu, 241Am, 242Pu, 242Am, 242mAm, 242Cm, 243Am, 244Am, 244mAm, 244Cm, 246Cm, 252Cf.

These evaluations may be found in the BIPM-5 Monographie, on the CD-Rom NUCLIDE published by the LNHB or in the web pages: http://www.nucleide.org/NucData.htm

A goal of the DDEP is to avoid future duplication of effort by disseminating these critically evaluated data with the hope that they will be included in many other collections of decay data.

VI

REFERENCES

[87Ta] Table de Radionuclides, F. Lagoutine, N. Coursol, J. Legrand. ISBN 2-7272-0078-1 (LMRI, 1982-1987).

[85Zi] W.L. Zijp, Netherland Energy Research Foundation, ECN, Petten, The Netherlands, Rep. ECN-179.

[96He] R.G. Helmer, Proceedings of the Int. Symp. "Advances in alpha-, beta- and gamma-ray Spectrometry", St. Petersburg, September 1996, p. 71.

[96Be] M.-M. B, B. Duchemin and J. Lam. Nucl. Instrum. Methods A369 (1996) 523 and Bulletin du Bureau National de Mtrologie 110 (1998).

[99In] Table de Radionuclides. Introduction, nouvelle version. Introduction, revised version. Einleitung, berarbeitete Fassung. ISBN 2-7272-0201-6, BNM-CEA/LNHB BP 52, 91191 Gif-sur-Yvette Cedex, France.

[99Be] M.-M. B, E. Browne, V. Chechev, R.G. Helmer, E. Schnfeld. Table de Radionuclides, ISBN 2-7272-0200-8 and ISBN 2-7272-0211-3 (LNHB, 1988-1999).

[04Be] M.-M. B, E. Browne, V. Chechev, V. Chist, R. Dersch, C. Dulieu, R.G. Helmer, T.D. MacMahon, A.L. Nichols, E. Schnfeld. Table of Radionuclides, Monographie BIPM-5, ISBN 92-822-2207-7 (set) and ISBN 92-822-2205-5 (CD), CEA/BNM-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France. and M.-M. B, E. Browne, V. Chechev, V. Chist, R. Dersch, C. Dulieu, R.G. Helmer, N. Kuzmenco, A.L. Nichols, E. Schnfeld. NUCLIDE, Table de Radionuclides sur CD-Rom, Version 2-2004, CEA/BNM-LNHB, 91191 Gif-sur-Yvette, France.

[06Be] Marie-Martine B, Vanessa CHIST, Christophe DULIEU; Edgardo BROWNE, Coral BAGLIN; Valery CHECHEV, Nikolay KUZMENKO; Richard G. HELMER; Filip G. KONDEV; T. Desmond MACMAHON; Kyung Beom LEE. Table of Radionuclides, Monographie BIPM-5, vol. 3, ISSN 92-822-2204-7 (set), ISBN 92-822-2218-7 (Vol. 3) and ISBN 92-822-2219-5 (CD), CEA/LNE-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France.

[08Be] Marie-Martine B, Vanessa CHIST, Christophe DULIEU; Edgardo BROWNE; Valery CHECHEV, Nikolay KUZMENKO; Filip G. KONDEV; Aurelian LUCA; Mnica GALN; Andrew PEARCE; Xiaolong HUANG. Table of Radionuclides, Monographie BIPM-5, vol.4, ISBN 92-822-2230-6 (Vol. 4) and ISBN 92-822-2231-4 (CD), CEA/LNE-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France.

[10Be] Marie-Martine B, Vanessa CHIST, Christophe DULIEU, Xavier MOUGEOT, Edgardo BROWNE, Valery CHECHEV, Nikolay KUZMENKO, Filip G. KONDEV, Aurelian LUCA, Mnica GALAN, Arzu ARINC, Xiaolong HUANG, Alan NICHOLS. Table of Radionuclides, Monographie BIPM-5, vol.5, ISBN 13 978-92-822-2234-8 (Vol. 5) et 13 978-92-822-2235-5 (CD-Rom), CEA/LNE-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France. Table of Radionuclides, Monographie BIPM-5, Commentaires, vol.5, ISBN 13 978-92-822-2235-5 (CD-Rom), CEA/LNE-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France.

[11Be] Marie-Martine B, Vanessa CHIST, Christophe DULIEU, Xavier MOUGEOT, Valery CHECHEV, Nikolay KUZMENKO, Filip G. KONDEV, Aurelian LUCA, Mnica GALN, Arzu ARINC, Xiaolong HUANG, B. WANG, Alan NICHOLS. Table of Radionuclides, Monographie BIPM-5, vol.6, ISBN 13 978-92-822-2242-3 (Vol. 6) et 13 978-92-822-2243-0 (CD-Rom), CEA/LNE-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France. Table of Radionuclides, Monographie BIPM-5, Commentaires, vol.6, ISBN 13 978-92-822-2243-0 (CD-Rom), CEA/LNE-LNHB, 91191 Gif-sur-Yvette, France and BIPM, Pavillon de Breteuil, 92312 Svres, France.

VII

AUTEURS POUR CORRESPONDANCE AUTHORS MAIL ADDRESSES

ADRESSEN DER AUTOREN AUTORES PARA CORRESPONDENCIA

Toutes demandes de renseignements concernant les donnes recommandes et la faon dont elles ont t tablies doivent tre adresses directement aux auteurs des valuations. Information on the data and the evaluation procedures is available from the authors listed below. Informationen ber die Daten und Evaluationsprozeduren knnen bei den im folgenden zusammengestellten Autoren angefordert werden. Todos los pedidos de informacin sobre datos recomendados y los mtodos de evaluacion utilizados, deben dirigirse directamente a los autores de las evaluaciones. Dr. Arzu Arinc National Physical Laboratory Teddington, Middlesex, TW11 OLM, United Kingdom E-mail: [email protected]

Dr. Marie-Martine B CEA/LNHB 91191 Gif-sur-Yvette, CEDEX, France Tel: 33-1-69-08-46-41 Fax: 33-1-69-08-26-19 E-mail: [email protected]

Dr. Valery P. Chechev V.G. Khlopin Radium Institute 28, 2nd Murinsky Ave., 194021 St. Petersburg, Russia Tel: 007 (812) 2473706 Fax: 007 (812) 2478095 E-mail: [email protected]

Dr. Vanessa Chist CEA/LNHB 91191 Gif-sur-Yvette, CEDEX, France Tel: 33-1-69-08-63-07 E-mail: [email protected]

Dr. Mnica Galn CIEMAT, Laboratorio de Metrologa de Radiaciones Ionizantes Avenida de la Complutense, 22 28040 Madrid, Spain E-mail: [email protected]

Dr. Xialong Huang China Nuclear Data center PO Box 275 (41) Beijing, China E-mail: [email protected]

VIII

Dr. Filip G. Kondev Applied Physics and Nuclear Data, Nuclear Engineering Division Argonne National Laboratory 9700 South Cass Ave. Argonne, IL 60439, USA Tel: 1-(630) 252-4484 Fax: 1-(630) 252-5287 E-mail: [email protected]

Dr. Aurelian Luca IFIN-HH/Radionuclide Metrology Laboratory 407 Atomistilor street PO Box MG-6 077125 Mahurele, Ilfov County, Romania E-mail: [email protected]

Dr. Xavier Mougeot CEA/LNHB 91191 Gif-sur-Yvette, CEDEX, France E-mail: [email protected]

Dr. Alan L. Nichols Department of Physics University of Surrey Guildford GU2 7XH, United Kingdom Tel: 44-1235-524077 E-mail: [email protected]

IX

RULES FOR EVALUATION AND COMPILATIONS

1. DATA SOURCES Two main sources of data are used to obtain the recommended values: - specific data evaluated from all available original publications (e.g., half-life), - data already evaluated and compiled by specialists (e.g., Q-values); if a subsequent experimental

study exists, the resulting measured value may be used, and its reference be included in a list of references for such a radionuclide.

2. EVALUATION RULES All intermediate stages in the compilation and evaluation of a decay parameter are not presented in detail in order to avoid unnecessary complexity. The main stages comprise the following: - critical analysis of published results and, if necessary, correction of these results to account for more

recent values hitherto unavailable to the original experimentalists; as a rule, results without associated uncertainties are discarded, and the rejection of values is documented;

- data obtained through private communications are used only when all of the necessary information

has been provided directly by the scientist who performed the measurements; - adjustments may be made to the reported uncertainties; - recommended values are deduced from an analysis of all measurements (or theoretical

considerations), along with their standard deviations with a 1 confidence level. 2.1. Evaluation of uncertainties Definitions from Guide to the expression of uncertainty in measurement [1]: Uncertainty (of measurement): parameter associated with the result of a measurement that characterizes the dispersion of the values that could reasonably be attributed to the measurand. Standard uncertainty: uncertainty of the result of a measurement expressed as a standard deviation. Type A evaluation (of uncertainty): method of evaluation of uncertainty by the statistical analysis of a series of observations. Type B evaluation (of uncertainty): method of evaluation of uncertainty by means other than the statistical analysis of a series of observations.

XI

The uncertainties given by authors are re-evaluated by combining the standard uncertainties A and B through the general law of variance propagation:

22 BAcu (1) where uc is the combined standard uncertainty, A is the type A standard deviation, and B is the type B standard uncertainty. When the authors give insufficient information concerning their uncertainty calculations, the combined uncertainty uc may be estimated by the evaluator, based on a knowledge of the measurement method(s). 2.2. Determination of the best value and associated uncertainty (a) Results obtained by one author using one method Sometimes only the final mean value and the combined standard uncertainty are given in the original publication. The following procedure is adopted if sufficient details are known. For n individual values ai (i = 1n), the best value is the arithmetical mean:

n

i

i

naa

1 (2)

with type A standard deviation:

2

12

)1()(

)(

nnaa

a i iA (3)

If there are m contributions Bj (j = 1m) to the type B standard uncertainty that are independent of each other:

2

1

1

2

m

jBjB a (4)

Combined standard uncertainty:

aaau BAc 22 (5) Recommended value: auaa c (6) (b) Results obtained by several authors employing the same method For n individual values )...1( niai having a standard deviation Ai and a type B uncertainty Bi, the best value is obtained by taking the mean weighted by the inverse of the variances.

XII

22

/1/

Aii

Aiii aa

(7)

The associated values A, B are:

2

1

2/1

iAiA a (8)

minBiiB

a or 2minBiiB a or minBB a depending on the individual case, although aB cannot be less than the smallest Bi. A and B are combined quadratically to determine uc:

aaau BAc 22 (9) and the recommended value is given by the expression: auaa c (10) (c) Results obtained by different methods When different measurement techniques have been applied, a weighted average is calculated using the combined uncertainties of the individual values as weights. For n independent values ai, each with a combined standard uncertainty uci, a weight pi proportional to the inverse of the square of the individual uci can be assigned to each value.

n

ii

n

iii

w

p

apa

1

1 (11)

where the weights are ./1 2ici

up An internal and an external uncertainty can be assigned to the mean value [2, 3]:

2

1

2/1

icwint i

ua (12)

The internal variance wint a2 is the expected uncertainty of the mean, based on the individual a priori variances 2

icu (by uncertainty propagation).

The external uncertainty is given by the equation:

21

2

22

/11/

i

i

c

cwiiwext un

uaaa (13)

XIII

The external variance wext a2 includes the scatter of the data, and is based on the amount by which each ai deviates from the mean when measured as a fraction of each given uncertainty .icu A measure of the consistency of the data is given by the ratio [2, 3]:

1// 2 nintext (14) If this ratio is significantly greater than unity, at least one of the input data most probably has an underestimated

icu which should be increased.

A critical value of 1/2 n at 1 % confidence level is used as a practical test for discrepant data. The following table lists critical values of 1/2 n for an increasing degree of freedom 1 n [4].

critical 2/(n 1)

critical 2/(n 1)

1 6.6 12 2.2 2 4.6 13 2.1 3 3.8 14 2.1 4 3.3 15 2.0 5 3.0 16 2.0 6 2.8 17 2.0 7 2.6 18-21 1.9 8 2.5 22-26 1.8 9 2.4 27-30 1.7

10 2.3 11 2.2 >30 1 + 2.33 /2

If )1/(critical)1/( 22 nn , the recommended value is given by: wintw aaa (15) If )1/(critical)1/( 22 nn , the method of limitation of the relative statistical weight [3, 5] is recommended when there are three or more values; uncertainty of a value contributing more than 50 % to the total weight is increased to reduce its contribution to 50 % . The weighted and unweighted average and critical 1/2 n are then recalculated:

if 1/critical1/ 22 nn , the recommended value is given by: wextwintw aaaa and oflarger the (16) if 1/critical1/ 22 nn , the weighted or unweighted mean is chosen, depending on whether or not the uncertainties of the average values make them overlap with each other. If overlap occurs, the weighted average is recommended; otherwise the unweighted average is chosen. In either case, the uncertainty can be increased to cover the most accurate value.

Parameters evaluated according to these procedures and rules include half-lives, number of emitted particles, and some internal-conversion coefficients. All remaining data given in the tables of recommended data are generally taken from compilations.

XIV

2.3. Balanced decay schemes All the probabilities for transitions and emitted radiations correspond to balanced decay schemes and permit the formulation of a fully consistent set of values. This balance implies the fulfillment of physical conservation principles as follows: The sum of the transition probabilities for all the transitions (, , ) is equal to 1 (or 100 %);

consequently, the sum of all the -ray transition probabilities (photons + internal conversion electrons) and all the (, , or ) transitions feeding directly to the ground state is equal to 1 (or 100 %).

For an excited nuclear level, the sum of the transition probabilities (, , , ) feeding the level is

equal to the sum of the transition probabilities depopulating this level; If the relative -ray emission probabilities

irelP are known, the absolute emission probability

P(abs)i can be obtained from the equation: NrelPabsP ii (17)

where N is the normalization factor, which may be determined from the equation: ,11 BrelPN

iti i

(18) where ti is the total conversion coefficient, and B, the (, , or ) absolute branching to the ground state. The sum in equation (18) includes all the -ray transitions feeding the ground state. 3. COMPILATIONS 3.1. and electron capture transitions Depending on the individual radionuclide, the -particle transition energies are either evaluated from experimental data (maximum energies), or deduced from the atomic mass differences obtained from the tabulations of Audi and Wapstra [6] and the transition energies. The average -particle energies are generally computed [7], and their log ft values as well as their /+ ratios are calculated using the tables of Gove and Martin [8]. Electron-capture transition energies are deduced from atomic mass differences and -ray transition energies. Capture probabilities PK, PL, for allowed and non-unique first forbidden transitions can be calculated from equations where the ratios of the radial wave function components of the electron [9-11] and the corrective terms for exchange XL/K [12-16] are evaluated from tables. 3.2. -ray transitions Internal conversion coefficients of pure multipolarity transitions are evaluated and compared with theoretical values that are interpolated from the tables of either Rsel et al. using a cubic spline method for 30 < Z < 104 [17], or Band et al. [18]. The agreement of these theoretical values with experimental results is about 3 %. Internal-conversion coefficients are calculated as described in Ref. [19] in order to include the effects of nuclear penetration in some M1 and E2 transitions.

XV

Internal conversion coefficients for transitions with mixed multipolarities (e.g., M1 + E2) are calculated using tables of theoretical values using mixing ratios as shown below: i(M1+E2) = i(M1) 1/1+2 + i(E2) 2/1+2 (19) where i = K, L1, L2, T, refers to the individual atomic shell. coefficients for pair production are interpolated from theoretical values [20], with a precision between 5 % and 10 %. 3.3. Level spins and parities Level spins and parities are usually from Nuclear Data Sheets [21]. 3.4. Atomic shell constants K-shell fluorescence yields K and their uncertainties are taken from the evaluation of Bambynek et al. [22-24] with uncertainties ranging from 1 % (Z > 35) to 10 % (Z = 5), and from subsequent experimental results. Mean L-shell fluorescence yields L are taken from the evaluation of Schnfeld and Janen [25]. This evaluation includes both experimental [26-28] and theoretical values [29], and their uncertainties are equal to 4 % (for Z > 29). Mean M-shell fluorescence yields M are obtained from the fitting of experimental data by Hubbell [28, 30]. Relative X-ray emission rates (K/K) are taken from Schnfeld and Janen [25], and K1/K2 from the theoretical values of Scofield [31]; uncertainties are assumed to be of the order of 1 %. X-ray radiation energies are taken from the tables of Bearden [32]. Relative emission probabilities of K-Auger electron groups are deduced from the X-ray ratio, with uncertainties of the order of 3 % [25]. Energies of the K and L-Auger electrons are taken from Larkins [33]. The mean number of vacancies created in the L shell (from one K hole) KLn and in the M shell (from one L hole) LMn are estimated from the preceding values. 3.5. 20cm energy

20cm energy is defined as 510.998 902 (21) keV, as given by the CODATA Group [34].

XVI

REFERENCES

[1] Guide to the expression of uncertainty in measurement, ISBN 92-67-20185-X ISO, Geneva, 1993. [2] WINKLER, G., Data fitting and evaluation techniques for radioactive decay data, Proc. Symp. on

Nuclear Data Evaluation Methodology, Brookhaven National Laboratory, USA, October 1992, World Scientific, Singapore (1993).

[3] ZIJP, W.L., On the statistical evaluation of inconsistent measurement results illustrated on the example of the 90Sr half-life, ECN Petten, Report ECN-179 (1985).

[4] BEVINGTON, P.R., Data Reduction and Error Analysis for the Physical Sciences, Appendix C-4, McGraw-Hill (1969).

[5] X-ray and gamma-ray standards for detector calibration, IAEA-TECDOC-619, Vienna (1991). [6] AUDI, G., WAPSTRA, A.H., The 1995 Atomic Mass Evaluation, Nucl. Phys. A595 (1995) 4. [7] ENSDF Logft program, ENSDF analysis and checking codes, Brookhaven National Laboratory,

USA. [8] GOVE, N.B., MARTIN, M.J., Nucl. Data Tables A10 (1971) 205. [9] SUSLOV, Y.P., Bull. Acad. Sci. USSR Phys. Ser. 33 (1969) 74. [10] BEHRENS, H., JANECKE, J., in Landolt-Bornstein: Numerical Data and Functional Relationships

in Science and Technology, New Series Group 1, Vol. 4: Numerical Tables for Beta Decay and Electron Capture, Springer-Verlag, Berlin (1969).

[11] MARTIN, M.J., BLICHERT-TOFT, P.H., Nucl. Data Tables A8 (1970) 1. [12] BAHCALL, J.N., Phys. Rev. 129 (1963) 2683; ibid., Phys. Rev. 132 (1963) 362; ibid., Nucl. Phys.

71 (1965) 267. [13] FAESSLER, J.A., HUSTER, E., KRAFFT, O., KRAHN, F., Z. Phys. 238 (1970) 352. [14] SUSLOV, Y.P., Bull. Acad. Sci. USSR Phys. Ser. 34 (1970) 91. [15] VATAI, E., Nucl. Phys. A156 (1970) 541. [16] SCHNFELD, E., Appl. Radiat. Isot. 49 (1998) 1353. [17] RSEL, F., FRIES, H.M., ALDER, K., PAULI, H.C., At. Data Nucl. Data Tables 21 (1978) 91. [18] BAND, I.M., TRZHASKOVSKAYA, M.B., NESTOR Jr., C.W., TIKKANEN, P.O., RAMAN, S.,

At. Data Nucl. Data Tables 81 (2002) 1. [19] PAULI, H.C., RAFF, U., A computer program for international conversion coefficients and particles

parameters, Computer Physics Communications 9 (1975) 392. [20] SCHLUTER, P., SOFF, G., At. Data Nucl. Data Tables 24 (1979) 509. [21] NUCLEAR DATA SHEETS, National Nuclear Data Center, Brookhaven National Laboratory, USA. [22] BAMBYNEK, W., CRASEMANN, B., FINK, R.W., FREUND, H.-U., MARK, H., SWIFT, C.D.,

PRICE, R.E., VENUGOPALA RAO, P., Rev. Mod. Phys. 44 (1972) 716. [23] BAMBYNEK, W., Proc. Conf. on X-Ray and Inner Shell Processes in Atoms, Molecules and Solids,

20-24 August 1984, Leipzig, Germany. [24] W. BAMBYNEK, Reorganization of atomic shells after radioactive decay, Proc. 2nd Int. Summer

School, Lowlevel measurements of man-made radionuclides in the environment, June 1990, La Rabida, Huelva, Spain, World Scientific, Singapore (1991) 156-174.

[25] SCHNFELD, E., JANSZEN, H., PTB report Ra-37 (1995). [26] MITCHELL, I.V., BARFOOT, K.M., Particle-induced X-Ray Emission Analysis, Application to

Analytical Problems, Nucl. Sci. Appl. 1 (1981) 99-162. [27] COHEN, D.D., Nucl. Instrum. Meth. Phys. Res. B22 (1987) 55. [28] HUBBELL, J.H., Bibliography and current status of K, L, and higher shell fluorescence yields for

computation of photon energy absorption coefficients. NIST internal report 89-4144 (1989). [29] PURI, S., MEHTA, D., CHAND, B., SINGH, N., TREHAN, P.N., X-Ray Spectrometry 22 (1993)

358. [30] HUBBELL, J.H., TREHAN, P.N., SINGH, N., CHAND, B., MEHTA, D., GARG, M.L., GARG,

R.R., SINGH, S., PURI, S., J. Phys. Chem. Ref. Data 23 (1994) 339. [31] SCOFIELD, J.H., Phys. Rev. A9 (1974) 1041. [32] BEARDEN, J.A., Rev. Mod. Phys. 39 (1967) 78. [33] LARKINS, F.P., At. Data Nucl. Data Tables 20 (1977) 313. [34] MOHR, P.J., TAYLOR, B.N., Rev. Mod. Phys. 72 (2000) 351.

XVII

Table of contents (Volumes 1 to 7 All nuclides sorted by increasing mass number)

Mass Nuclide Page Mass Nuclide Page Mass Nuclide Page Mass Nuclide Page3 H-3 1

99 Mo-99 255 186 Re-186 659 224 Ra-224 9277 Be-7 9 99 Tc-99 273 195 Au-195 665 225 Ra-225 931

11 C-11 13 99 Tc-99m 279 198 Au-198 669 225 Ac-225 93513 N-13 17 108 Ag-108 289 201 Tl-201 677 226 Ra-226 94914 C-14 21 108 Ag-108m 293 203 Hg-203 681 227 Ac-227 95515 O-15 25 109 Pd-109 297 203 Pb-203 685 227 Th-227 96118 F-18 29 109 Cd-109 307 204 Tl-204 691 228 Ra-228 97322 Na-22 33 110 Ag-110 315 206 Hg-206 695 228 Ac-228 97724 Na-24 39 110 Ag-110m 321 206 Tl-206 699 228 Th-228 101332 P-32 47 111 In-111 333 207 Tl-207 707 231 Th-231 102333 P-33 51 123 Te-123m 339 207 Bi-207 711 231 Pa-231 103135 S-35 53 123 I-123 343 208 Tl-208 721 232 Th-232 105336 Cl-36 55 124 Sb-124 353 209 Tl-209 737 232 U-232 105937 Ar-37 59 125 Sb-125 387 209 Pb-209 743 233 Th-233 106740 K-40 63 125 I-125 401 209 Po-209 745 233 Pa-233 107941 Ar-41 69 127 Sb-127 407 210 Tl-210 749 234 Th-234 109344 Sc-44 73 127 Te-127 419 210 Pb-210 753 234 Pa-234 109944 Ti-44 79 127 Te-127m 427 210 Bi-210 759 234 Pa-234m 111945 Ca-45 85 129 I-129 435 210 Po-210 763 234 U-234 113146 Sc-46 87 131 I-131 439 211 Pb-211 767 235 U-235 113751 Cr-51 91 131 Xe-131m 447 211 Bi-211 773 236 U-236 115154 Mn-54 95 132 Te-132 449 211 Po-211 779 236 Np-236 115555 Fe-55 101 133 I-133 453 211 At-211 785 236 Np-236m 116156 Mn-56 105 133 Xe-133 459 212 Pb-212 793 237 U-237 116556 Co-56 111 133 Xe-133m 465 212 Bi-212 797 237 Np-237 117157 Co-57 129 133 Ba-133 469 212 Po-212 805 238 U-238 118157 Ni-57 139 134 Cs-134 479 213 Bi-213 807 238 Np-238 118759 Fe-59 145 135 Xe-135m 487 213 Po-213 813 238 Pu-238 119359 Ni-59 153 137 Cs-137 493 214 Pb-214 817 239 U-239 120560 Co-60 157 139 Ce-139 501 214 Bi-214 825 239 Np-239 121163 Ni-63 161 140 Ba-140 507 214 Po-214 839 239 Pu-239 121764 Cu-64 163 140 La-140 513 215 Bi-215 843 240 Pu-240 124165 Zn-65 173 141 Ce-141 525 215 Po-215 853 241 Pu-241 125166 Ga-66 179 147 Nd-147 531 215 At-215 859 241 Am-241 126167 Ga-67 191 147 Pm-147 541 216 Po-216 861 242 Pu-242 127168 Ga-68 203 152 Eu-152 547 217 At-217 865 242 Am-242 127768 Ge-68 209 153 Sm-153 567 217 Rn-217 869 242 Am-242m 128375 Se-75 211 153 Gd-153 579 218 Po-218 871 242 Cm-242 129579 Se-79 221 154 Eu-154 585 218 At-218 873 243 Am-243 130385 Kr-85 223 155 Eu-155 597 218 Rn-218 875 243 Cm-243 131385 Sr-85 227 159 Gd-159 605 219 At-219 877 244 Am-244 132188 Y-88 231 166 Ho-166 611 219 Rn-219 881 244 Am-244m 132589 Sr-89 237 166 Ho-166m 615 220 Rn-220 891 244 Cm-244 133390 Sr-90 241 169 Yb-169 625 221 Fr-221 895 245 Cm-245 134190 Y-90 243 170 Tm-170 631 222 Rn-222 903 246 Cm-246 134990 Y-90m 247 177 Lu-177 637 223 Fr-223 905 252 Cf-252 135593 Nb-93m 251 182 Ta-182 645 223 Ra-223 915

XIX

Table of contents (Volumes 1 to 7 All nuclides sorted by alphabetical order)

Mass Nuclide Page Mass Nuclide Page Mass Nuclide Page Mass Nuclide Page225 Ac-225 935 60 Co-60 157 237 Np-237 1171

44 Sc-44 73227 Ac-227 955 51 Cr-51 91 238 Np-238 1187 46 Sc-46 87228 Ac-228 977 134 Cs-134 479 239 Np-239 1211 75 Se-75 211108 Ag-108 289 137 Cs-137 493 15 O-15 25 79 Se-79 221108 Ag-108m 293 64 Cu-64 163 32 P-32 47 153 Sm-153 567110 Ag-110 315 152 Eu-152 547 33 P-33 51 85 Sr-85 227110 Ag-110m 321 154 Eu-154 585 231 Pa-231 1031 89 Sr-89 237241 Am-241 1261 155 Eu-155 597 233 Pa-233 1079 90 Sr-90 241242 Am-242 1277 18 F-18 29 234 Pa-234 1099 182 Ta-182 645242 Am-242m 1283 55 Fe-55 101 234 Pa-234m 1119 99 Tc-99 273243 Am-243 1303 59 Fe-59 145 203 Pb-203 685 99 Tc-99m 279244 Am-244 1321 221 Fr-221 895 209 Pb-209 743 123 Te-123m 339244 Am-244m 1325 223 Fr-223 905 210 Pb-210 753 127 Te-127 41937 Ar-37 59 66 Ga-66 179 211 Pb-211 767 127 Te-127m 42741 Ar-41 69 67 Ga-67 191 212 Pb-212 793 132 Te-132 449

211 At-211 785 68 Ga-68 203 214 Pb-214 817 227 Th-227 961215 At-215 859 153 Gd-153 579 109 Pd-109 297 228 Th-228 1013217 At-217 865 159 Gd-159 605 147 Pm-147 541 231 Th-231 1023218 At-218 873 68 Ge-68 209 209 Po-209 745 232 Th-232 1053219 At-219 877 3 H-3 1 210 Po-210 763 233 Th-233 1067195 Au-195 665 203 Hg-203 681 211 Po-211 779 234 Th-234 1093198 Au-198 669 206 Hg-206 695 212 Po-212 805 44 Ti-44 79133 Ba-133 469 166 Ho-166 611 213 Po-213 813 201 Tl-201 677140 Ba-140 507 166 Ho-166m 615 214 Po-214 839 204 Tl-204 691

7 Be-7 9 123 I-123 343 215 Po-215 853 206 Tl-206 699207 Bi-207 711 125 I-125 401 216 Po-216 861 207 Tl-207 707210 Bi-210 759 129 I-129 435 218 Po-218 871 208 Tl-208 721211 Bi-211 773 131 I-131 439 238 Pu-238 1193 209 Tl-209 737212 Bi-212 797 133 I-133 453 239 Pu-239 1217 210 Tl-210 749213 Bi-213 807 111 In-111 333 240 Pu-240 1241 170 Tm-170 631214 Bi-214 825 40 K-40 63 241 Pu-241 1251 232 U-232 1059215 Bi-215 843 85 Kr-85 223 242 Pu-242 1271 234 U-234 113111 C-11 13 140 La-140 513 223 Ra-223 915 235 U-235 113714 C-14 21 177 Lu-177 637 224 Ra-224 927 236 U-236 115145 Ca-45 85 54 Mn-54 95 225 Ra-225 931 237 U-237 1165

109 Cd-109 307 56 Mn-56 105 226 Ra-226 949 238 U-238 1181139 Ce-139 501 99 Mo-99 255 228 Ra-228 973 239 U-239 1205141 Ce-141 525 13 N-13 17 186 Re-186 659 131 Xe-131m 447252 Cf-252 1355 22 Na-22 33 217 Rn-217 869 133 Xe-133 45936 Cl-36 55 24 Na-24 39 218 Rn-218 875 133 Xe-133m 465

242 Cm-242 1295 93 Nb-93m 251 219 Rn-219 881 135 Xe-135m 487243 Cm-243 1313 147 Nd-147 531 220 Rn-220 891 88 Y-88 231244 Cm-244 1333 57 Ni-57 139 222 Rn-222 903 90 Y-90 243245 Cm-245 1341 59 Ni-59 153 35 S-35 53 90 Y-90m 247246 Cm-246 1349 63 Ni-63 161 124 Sb-124 353 169 Yb-169 62556 Co-56 111 236 Np-236 1155 125 Sb-125 387 65 Zn-65 17357 Co-57 129 236 Np-236m 1161 127 Sb-127 407

XX

Comments on evaluation 3H

KRI/V.P. Chechev April 2006

3H Comments on Evaluation by V.P. Chechev

The initial 3H decay data evaluation was done by Chechev in 1998 (1999Be). This current

(revised) evaluation was carried out in April 2006. The literature available by April 2006 was included. 1. DECAY SCHEME

3H decays 100 % by -emission directly to the ground state of 3He.

2. NUCLEAR DATA Q value is from 2003Au03.

The evaluated 3H half-life is based on the experimental data given in Table 1. This table has been

taken from the paper of Lucas and Unterw eger (2000Lu17) which contains a comprehensive review and critical evaluation of the half-life of tritium.

Table 1. Experimental values of the 3H half-life (in years)

Reference Author(s) Measurement method

Half-life (years)

Stated uncertainty (years)

Meaning of the stated

uncertainty

Comments

1936 McMillan McMillan

Ionization current >10 None

No uncertainty

Followed decay of radiation from irradiated beryllium for 4 months. OMITTED: limit only

1939 Alvarez

Alvarez and Cornog Beta counting 0.41 0.11 Not given

One sample followed for 80 d. Chamber had diffusion losses. OMITTED: updated in 1940Alvarez

1940 Alvarez

Alvarez and Cornog Beta counting >10 None

No uncertainty

One sample followed for 5 months in new chamber. OMITTED: limit only

1940On01 ONeal and Goldhaber Beta counting 31 8 Not given Counted tritium from irradiated lithium metal. OMITTED: outlier

1947Go08 Goldblatt et al. Ionization current 10.7 2.0 Not given

Hydrogen + tritium in ionization chamber over 18 d. OMITTED: outlier

1947No01 Novick Helium-3 collection 12.1 0.5 Not given Two samples; accumulation times of 51 d and 197 d

1949Jenks Jenks et al. Helium-3 collection 12.46 0.20 Not given Repeated measurements every two weeks until stable. OMITTED: updated in 1950Je60

1950Je60 Jenks et al. Helium-3 collection 12.46 0.10 Probable error a Four measurements over 206 d.

1951Jo15 Jones Beta counting 12.41 0.05 Probable error a Measurement of specific activity of tritium gas

1955Jo20 Jones Helium-3 collection 12.262 0.004 Not given Two samples; accumulation times of 578 d and 893 d

1958Po64 Popov et al. Calorimetry 12.58 0.18 Not given One sample; 21 measurements over 13 months

1963 Eichelberger

Eichelberger et al. Calorimetry 12.355 0.010

Probable error a

Two samples measured over four years. OMITTED: updated in 1967Jo09

1



1966Merritt Merritt and Taylor Beta counting 12.31 0.13 Not given Five gas counting measurements over 13 years

1967Jo09 Jordan et al. Calorimetry 12.346 0.002 Probable error a

Five samples; 266 measurements over 6 years. OMITTED: updated in 1977RuZZ

1967Jo10 Jones Helium-3 collection 12.25 12.31

0.08 0.42

99.7 % confidence

limits

Two samples; accumulation times of 450 d to 800 d. Only the first value is usually quoted

1977RuZZ Rudy and Jordan Calorimetry 12.3232 0.0043 95 %

confidence limits

Eight samples; 1353 measurements over 16 years

1980Un01 Unterweger et al. Beta counting 12.43 0.05 1 standard uncertainty

Two sets of gas counting measurements 18 years apart. OMITTED: updated in 2000Unterweger

1987Bu28 Budick et al. Bremsstrahlung counting 12.29 0.10 Not given Two samples of tritium + xenon gas measured over 320 d. OMITTED: updated in 1991Bu13

1987Ol04 Oliver et al. Helium-3 collection 12.38 0.03 1 standard uncertainty

Fifteen samples, each with accumulation times of 1 year to 2 years

1987Si01 Simpson Beta counting 12.32 0.03 1 standard uncertainty Tritium implanted in Si(Li) detector measured over 5.5 years

1988 Akulov Akulov et al. Helium-3 collection 12.279 0.033 1 standard uncertainty

Five series of measurements over 846 d

1991Bu13 Budick et al. Bremsstrahlung counting 12.31 0.03 1 standard uncertainty

Two samples of tritium + xenon gas measured over 5.5 years

2000 Unterweger

Unterweger and Lucas Beta counting 12.33 0.03

1 standard uncertainty

Three sets of gas counting measurements over 38 years

a The probable error, PE , is the deviation from the population mean, , such that 50 % of the observations may be expected to lie between PE and + PE . For a normal distribution, the probable error can be converted to the standard deviation by multiplying by 1.4826.

As seen from Table 1 there are a number of measurements of the tritium half -life. Three of them stand

out by their high prec ision (1955Jo20, 1967Jo09, 1977RuZZ). However, the uncertainties stated for the half -life in these works do not include an estimation of possible systematic errors. There are available newer measurements and discussions of the tritium half -life, so it is possible to estimate an "external" minimum uncertainty due to systematic effects (min) that should be added to the uncertainties stated in 1955Jo20, 1967Jo09 and 1977RuZZ. At that we can take into account the following circumstances:

a) The 3He collection res ult of 1955Jo20 has been obtained using only two points on each decay curve (for two samples). In the later work by the same method (1967Jo09) many experimental points were obtained on the decay curves (also for two samples) and the estimated systematic un certainty made up 0.8 % for a 99.7 % confidence level.

b) The result of 1977RuZZ is a continuation of the measurements of 1967Jo09 for two tritide solids by calorimetric method for an additional 12 years. The difference of results of 1967Jo09 and 1977RuZZ proved to be 0.2 %, more than 5exp from 1977RuZZ and more than 10exp from 1967Jo09.

c) The comparative analysis of measurements of the radioactivity concentrations in several NBS tritiated-water standards over an 18 -year period 1961 - 1978 (1980Un01) showed th at for agreement of measurements (at given tritium half -life) their estimated standard errors (including a calorimetric method) should not be less 0.2 %.

Thus we have sufficient grounds for adding the "external" systematic error min = 0.002 .T1/2 (3H) into the uncertainties quoted in 1955Jo20, 1967Jo09 and 1977RuZZ. Lucas and Unterweger (2000Lu17) estimated the standard uncertainty of 1955Jo20 as 0.030 yr and that of 1977RuZZ as 0.025 yr.

2



Table 2 shows the modified set of half -life values, which has been fo rmed from the original set by omitting the ten measurement results (see Comments in Table 1) and adjusting the uncertainties of 1955Jo20, 1977RuZZ and 1966Merritt. Latter was re-estimated in 2000Lu17. Table 2. Selected measurement results for tritium half -life (in years)

Reference Half-life Measurement method Comments on uncertainty

1947No01 12.1(5) 3He collection Authors stated uncertainty (ASU)

1950Je60 12.46(15) 3He collection ASU multiplied by 1.4826

1951Jo15 12.41(7) Beta counting Authors stated uncertainty

1955Jo20 12.262(30) 3He collection Uncertainty re-estimated in 2000Lu17

1958Po64 12.58(18) Calorimetry Authors stated uncertainty

1966Merritt 12.31(4) Beta counting Uncertainty re-estimated in 2000Lu17

1967Jo10 12.25(3) 3He collection Authors stated uncertainty

1977RuZZ 12.323(25) Calorimetry See text

1987Ol04 12.38(3) 3He collection Authors stated uncertainty

1987Si01 12.32(3) 3H implanted into Si(Li) Authors stated uncertainty

1988Akulov 12.279(33) 3He collection Authors stated uncertainty

1991Bu13 12.31(3) Bremsstrahlung Authors stated uncertainty

2000Unterweger 12.33(3) Three sets of gas counting measurements over 38 years

Authors stated uncertainty

A weighted average for the final data set is 12.312 with an internal unce rtainty of 0.010 and an

external uncertainty of 0.013 and a reduced 2/ = 1.6. An unweighted average is 12.33(3). Different statistical procedures from 1994Ka08 give the similar results: UINF, LWM, NORM 12.312(10), PINF, BAYS and MBAYS 12.312(13), IEXW 12.314(14), RAJ 12.311(10), CHV 12.317(16). Lucas and Unter weger (2000Lu17) used three other statistical procedures including the method of determining the median and the estimated standard deviation of the median and adopted the value of 12.318(25).

The LWEIGHT computer program using the LWM procedure has led to the recommended value of 12.312(10).

The EV1NEW computer program (2000Ch01) has chosen the weighted average of 12.312 and recommended the smallest experimental uncertainty of 0.025 as a final uncertainty.

The adopted value of the 3H half-life is 12.312(25) years, or 4497(9) days. It should be noted this half -life value has been evaluated for molecular tritium. The half -life of

atomic tritium is less by 0.26% (2004Ak16). See also 2005Ak04 for a bare triton half -life. 2.1. Tritium Beta End-Point Energy (E0)

The tritium beta end-point energy depends upon the chemical state of the tritium in an experiment. The expression for E0 of molecular tritium differs from that of a "bare" nucleus by the "chemical shift" E= B(RHe+) B(RT) (1985Ka21, 1989Re04) which is calculated taking into account the spectrum of

3



final states (SFS). (Here the B values indicate electron binding energies for He+ ion and tritium atom, R indicates a chemical state).

For known 3He-3H atom mass difference (Mc2) the tritium beta "end -point" energy measured in

some experiment is : E0 = Mc2 Erec [B(He) B(T)] + [B(RHe+) B(RT)] where Erec is the helium recoil energy. For tritium atom (nuclide) E0 = Mc2 3.4 eV 64.3 eV + E where E = 40.82 eV. With the recommended value of Mc2, the beta end-point energy for tritium nuclide is obtained by

this way as 18563.6 eV. It is difficult to estimate the uncertainty of the E calculation in1985Ka21. Supposing it about the evaluated uncertainty of Mc2 (Q value), we have E0 (3H nuclide) = 18.564(2) keV.

For real forms of tritium sources in beta -spectrometry experiments the 3H end-point energies differ from the atomic value. For a molecular forms HT, CH 3T, valine the calculated E0 makes 18572(2) eV. Below the measured end-point energies in some experiments are shown.

1987Bo07 Valine 18.579.4 4 eV 1993Ba08 Molecular tritium 18.574.8 0.6 eV 1993Su32 C14H15T6O2N3 18.578.3 5.1 eV 1995St26 Gaseous tritium 18.568.5 2.0 eV 2003Kr17 Gaseous tritium 18.570.5 eV

It should be noted that many works devoted to study of tritium beta -spectrum as it provided the most precise data of neutrino mass upper limit (see, for example, 2005Kr03, 2003Lo10, 2002Bo31 and references therein).

2.2. Average energy of beta particles of tritium per disintegration ()

In Table 3 the available data of the have been presented. The recommended value has been obtained as the weighted average after corrections into the original results of the experiments and calculations. The calculation of the with the LOGFT computer program using the adopted value Q = 18.591(1) keV gives 5.68 (0.0011) keV. Table 3. The available data of the tritium average beta energy (per disintegration, keV)

Reference Method Original Re-estimated Adopted

1950Je60 Calorimetry 5.69(4) 5.68(4) a 5.68(4)

1958Gr93 Calorimetry 5.57(1) 5.68(2) a 5.68(2)

1961Pi01 Calorimetry 5.73(3) 5.68(3) b 5.68(3)

1972Ma72 Calculation 5.7 5.7(1) d

1985Martin Calculation 5.684(5) 5.680(5) c 5.68(1) d

1985Garcia TDCR 5.70 5.70(2) d

1987Lagoutine, 1994Si21 Calculation 5.71(3) 5.70(3) c 5.70(3)

Recommended value 5.68(1) keV a Corrected for the adopted tritium half -life of 12.312 y and heat output of 0.324(1) W/g b Corrected for the adopted tritium half -life of 12.312 y c Corrected for the adopted decay energy (Q = 18.591 keV) d Uncertainty attributed by the evaluator

4



3. REFERENCES

1936McMillan E.M. McMillan, Phys. Rev. 49(1936)875 [Half-life]

1939Alvarez L.W. Alvarez and L. Cornog, Phys. Rev. 56(1939)613 [Half-life]

1940Alvarez L.W. Alvarez and L. Cornog, Phys. Rev. 57(1940)248 [Half-life]

1940On01 R.D. O'Neal and M. Goldhaber, Phys. Rev. 58(1940)574 [Half-life]

1947Go08 M. Goldblatt, E.S. Robinson, and R.W. Spence, Phys. Rev. 72(1947)973 [Half-life]

1947No01 A. Novick, Phys. Rev. 72(1947)972 [Half-life]

1949Jenks G.H. Jenks, J.A. Ghormley, and F.H. Sweeton, Phys. Rev. 75(1949)701 [Half-life]

1950Je60 G.H. Jenks, F.H. Sweeton, and J.A. Ghormley, Phys. Rev. 80(1950)990 [Half-life, average beta energy]

1951Jo15 W.M. Jones, Phys. Rev. 83(1951)537 [Half-life]

1955Jo20 W.M. Jones, Phys. Rev. 100(1955)124 [Half-life]

1958Gr93 D.P. Gregory and D.A. Landsman, Phys. Rev. 109(1958)2091 [Average beta energy]

1958Po64 M.M. Popov et al., Atomnaya Energ.4(1958)269; J. Nucl. Energy 9(1959)190 [Half-life]

1961Pi01 W.L. Pillinger, J.J. Hentges, and J.A. Blair, Phys. Rev.121(1961)232 [Average beta energy]

1963Eichelberger J.F. Eichelberger, G.R. Grove, and L.V. Jones. Progress Report MLM -1160, US Department of Energy, Mound Laboratory, Miamisburg, Ohio, June 1963, p.5-6 [Half-life]

1966Merritt J.S. Merritt, J.G.V. Taylor, Chalk River Report AECL-2510(1966) [Half-life]

1967Jo09 K.C. Jordan, B.C. Blanke, and W.A. Dudley, J. Inorg. Nucl. Chem. 29(1967)2129 [Half-life]

1967Jo10 P.M.S. Jones, J. Nucl. Materials 21(1967)239 [Half-life]

1972Ma72 J. Mantel, Intern. J. Appl. Rad. Isotopes 23(1972)407 [Average beta energy]

1977RuZZ C.R. Rudy and K.C. Jordan, In: MLM-2458, Monsanto Research Corporation, Miamisburg, Ohio(1977) [Half-life]

1980Un01 M.P. Unterweger et al., Intern. J. Appl. Rad. Isotopes 31(1980)611 [Half-life]

5



1985Garcia E. Garcia-Torano and A. Gra u Malonda, Comp. Phys. Commun. 36(1985)307. See also 1994Si21 [Average beta energy]

1985Ka21 I.G. Kaplan, G.V. Smelov, and V.N. Smutny, Phys.Lett. 161B(1985)389 [Beta end-point energy and Q-value]

1985Martin M.J. Martin, In: A handbook of radioactivity measurement procedures, NCRP Report No 58 (1985), 2nd Edition, NCRP, Bethesda, Maryland, 368-373 [Average beta energy]

1987Bo07 S.D. Boris et al., Phys.Rev.Lett. 58, 2019 (1987); Erratum Phys.Rev.Lett. 61, 245 (1988) [Beta end-point energy]

1987Bu28 B. Budick and Hong Lin, Bull.Amer.Phys.Soc.32 (1987)1063 [Half-life]

1987Lagoutine F. Lagoutine, N. Coursol, J. Legrand, Table de Radionucl ides, ISBN-2-7272-0078-1 (LMRI, 1982-1987) [Average beta energy]

1987Ol04 B.M. Oliver, H. Farrar IV, and M.M. Bretscher, Intern. J. Appl. Rad. Isotopes 38(1987)959 [Half-life]

1987Si01 J.J. Simpson, Phys. Rev. C35(1987)752 [Half-life]

1988Akulov Yu.A. Akulov, B.A. Mamyrin, L.V. Khabarin, V.S. Yudenich, and N.N. Ryazantseva, Zh. Tekh. Fiz. 14(1988)940, Sov. Tech. Phys. Lett. 14(1988)416 [Half-life]

1989Re04 A. Redondo and R.G.H. Robertson, Phys .Rev. C40(1989)368 [Beta end-point energy and Q-value]

1991Bu13 B. Budick, Jiansheng Chen, and Hong Lin, Phys. Rev. Lett. 67(1991)2630 [Half-life]

1993Ba08 H. Backe, H. Barth, J. Bonn et al., Nucl. Phys. A553(1991)313c [Beta end-point energy]

1993Su32 H. Sun, D. Liang, S. Chen et al. J. Chin, Nucl.Phys. 15(1993)261 [Beta end-point energy]

1994Ka08 S.F. Kafala, T.D. MacMahon, and P.W. Gray, Nucl. Instrum. Methods Phys. Res. A339(1994)151 [Evaluation technique]

1994Si21 B.R.S. Simpson and B.R. Meyer, Nucl. Instrum. Methods Phys. Res. A339(1994)14 [Average beta energy]

1995St26 W. Stoeffl and D.J. Decman, Phys. Rev. Lett. 75(1995)3237 [Beta end-point energy]

1999Be M.-M. B, E.Browne, V.Chechev et al. In: Table de Radionucl ides, CEA-ISBN 2-7272-0200-8, Comments on Evaluations, CEA-ISBN 2-7272-0211-3. 1999 [3H decay data evaluation-1998]

2000Ch01 V.P. Chechev and A.G. Egorov, Appl. Radiat. Isot. 52(2000)601 [Evaluation technique]

2000Lu17 L.L. Lucas and M.P. Unterweger, J. Res. Natl. Inst. Stand. Technol. 104(2000)541 [Half-life evaluation]

6



2000Unterweger M.P. Unterweger and L.L. Lucas, Appl. Radiat. Isot. 52(2000)527 [Half-life]

2002Bo31 J. Bonn, B. Bornschein, L. Bornschein et al., Prog. Part. Nucl. Phys. 48(2002)133 [Tritium beta-spectrum]

2003Au03 G. Audi, A.H. Wapstra, and C. Thibault, Nucl. Phys. A729(2003)337 [Q-value]

2003Kr17 Ch. Kraus, J. Bonn, B. Bornschein et al., Nucl. Phys. A721(2003)533c [Beta end-point energy]

2003Lo10 V.M. Lobashev. Nucl. Phys. A719(2003)153c [Tritium beta-spectrum]

2004Ak16 Yu.A. Akulov and B.A. Mamyrin. Phys. Lett. B600(2004)41 [Half-life]

2005Ak04 Yu.A. Akulov and B.A. Mamyrin, Phys. Lett. B610(2005)45 [Half-life]

2005Kr03 Ch. Kraus, B. Bornschein, L. Bornschein et al., Eur. Phys. J. C40(2005)447 [Tritium beta-spectrum]

7

Comments on evaluation 7Be

INEEL/R. G. Helmer Jan. 2001 PTB/E. Schnfeld

7Be - Comments on Evaluation of Decay Data by R. G. Helmer

This evaluation was originally done in 1996 by R. G. Helmer and E. Schnfeld and minor

editing was added in December 2000. 1. Decay Scheme

This decay scheme is complete since the only levels in 7Li below the decay energy are

populated. 2. Nuclear Data

The Q value is from the mass evaluation in 1995Au04.

The adopted half-life is 53.22 (6) days. The 7Be half-life has been observed to vary depending on the chemical form of the 7Be. Some of these measured variations are: Reference Chemical forms compared (T 104)/T 1949Se20 Be - BeO 1.5 (9) 1953Kr16 Be - BeO 1.3 (5) BeO- BeF2 6.1 (6) Be - BeF2 7.4 (5) 1956Bo36 Be - BeF2 12 (1) 1970Jo21 BeO- BeF2 11.3 (6) BeO - BeBr2 14.7 (6) BeO- Be4O(CH3COO)6 -7.2 (6) BeO- Be(C5H5)2 8.0 (7) BeO- Be(OH2)4 -3.7 (8) BeF2- Be4O(CH3COO)6 -18.5 (8) Be(C5H5)2- Be(OH2)4 -11.7 (11) 1999Hu20 BeO - Be(OH)2 -149. BeO - Be2+(OH2)4 -98. 1999Ra12 Be in Au - Be in Al2O3 72 (7) Excluding the much larger changes reported by 1999Hu20 and 1999Ra12, these measured changes range from 0.01% to 0.2%, or from 0.005 to 0.10 days, or 0.08 days, if the organic compounds are also omitted.

The adopted value of 53.22 (6) is from Limitation of Relative Statistical Weight (LRSW) (1985ZiZY, 1992Ra09) analysis of 53 (2) (1940Hi01), 52.93 (22) (1949Se20), 53.61 (17) (1953Kr16), 53.0 (4) (1956Bo36), 53.5 (2) (1957Wr37), 53.1 (3) (1965En01), 53.52 (10) (1970Jo21), 53.0 (3) (1974Cr05), 53.17 (2) (1975La16), 53.16 (1) (1982ChZF), 53.284 (4) (1982RuZV), and 53.12 (7) (1996Ja10). In this analysis the uncertainty of 1982RuZV value was increased from 0.004 to 0.0088 so that its relative

9



weight was reduced from 83 % to 50 %. The weighted average of these values is 53.225 with an internal uncertainty of 0.006, a reduced-2 of 10.5, and an external uncertainty of 0.020. This uncertainty is increased by the LRSW method to 0.06 so that the most precise value of 53.284 is included; this uncertainty also includes the next most precise value of 53.16.

The chemical forms of the samples for which these half-lives were determined are: 1949Se20 Be metal or BeO and difference is not significant, 1953Kr16 Be metal, 1956Bo36 Be metal or BeF2 and difference is not significant, 1970Jo21 average of data for BeF2, BeO, and Be(C5H5)2, and 1975La16 isolated Be atoms in aluminum matrix.

The adopted half-life is dominated by the values of 1975La16, 1982ChZF, and 1982RuZV which contribute 10 %, 39 %, and 50 % of the relative weight, respectively. The values of 1982ChZF and 1982RuZV differ by ~ 10 and contribute 3.8 and 4.1 to the reduced-2 value of 10.5. Since these three values differ by 0.12 days and the chemical forms in the latter two cases are not known, the chemical variation data in the above table suggest that some of this difference may be due to chemical effects. This suggests that the adopted uncertainty of 0.06 days is reasonable for general use. In any case, the data on the chemical effects indicate that the adopted value can certainly be used for Be and BeO sources.

Values not used are 54.5 (J. F. Bonner as quoted in 1953Kr16, no uncertainty); and 54.3 (5) (1947BoAA as quoted in 1953Kr16, superseded by value of 1956Bo36); and 53.694 (6), 53.416 (6), and 54.226 (6) (1999Hu20). The values of 1999Hu20 have very small uncertainties and have very large variations, up to 1.5%, with chemical form which need to be confirmed. If this large shift and that of 1999Ra12 are correct, they would invalidate the uncertainty of our adopted value.

Also, the results of 2000Hu20 and 2000Li21 were obtained after this evaluation was completed,

but these results would not change the adopted value.

Recent experiments have shown that the half-life of 7Be increases as much as 0.7% by imbedding this radionuclide in different matrices. The recommended value presented in this evaluation should be adequate for Be and BeO samples. 2.1 Electron-capture transitions

The adopted value for the electron capture to the 477-keV level is P(477) = 10.44 % (4). This value is a weighted average of 10 (+20-7) (1938RuAA), 10.7 (20) (1949Wi13), 11.8 (12) (1949Tu06), 12.3 (6) (1951Di12), 10.35 (8) (1969TaZX), 10.47 (20) (1970MuZU), 10.42 (18) (1973Po10), 10.35 (8) (1974Go26), 10.10 (45) (1983Ba15), 10.61 (23) (1983Da14), 10.6 (5) (1983Do07), 10.9 (11) (1983Kn10), 10.7 (2) (1983Ma34), 9.8 (5) (1983No03), 11.4 (7) (1984Ev01), 10.61 (17) (1984Fi10), and 10.49 (7) (1984Sk01). This weighted average has an internal uncertainty of 0.039, a reduced-2 of 1.35, and an external uncertainty of 0.045. The adopted value is dominated by the values of 1969TaZX, 1974Go24, and 1984Sk01 which contribute 23 %, 23 %, and 30 % of the relative weight, respectively. The largest contribution to the reduced-2 is 0.6 from 1951Di12.

Values not used are 10.32 (16) (1962Ta11, superseded by 1969TaZX) and 10.5 (2) (W. Poenitz, 1966, superseded by 1973Po10).

The PK and PL values of 0.908 (12) and 0.092 (12) were calculated from the tables in 1998Sc28. The values from the LOGFT code are 0.97 and 0.03, which are different.

10



2.2 Gamma-ray transition

The -ray transition energy is computed from the -ray energy.

The internal-conversion coefficient is the measured value of 1964Kr04 and the mixing ratio was also determined by 1964Kr04. The theoretical values interpolated from the tables of 1976Ba63 are 7.73 10-7 for M1 and 2.96 10-6 for E2.

The gamma transition probability is : Within its uncertainty, P(477) = I(477) (1.0+) = P(477) With I(477) = 10.44 (4) % (c.f. 2.1)

3. Atomic Data

The fluorescence yield is from the compilation of 1994Hu23. 4. Radiations

The conversion electron emission intensity is computed from P(477) and K.

The -ray energy is from the evaluation of 2000He14. 5. Main Production Modes

6Li(d,n), 10B(p,), and 12C(3He,2) 6. References 1938RuAA L. H. Rumbaugh, R. B. Roberts, L. R. Hafstad, Phys. Rev. 54 (1938) 657 [P] 1940Hi01 J. E. Hill, Phys. Rev. 57 (1940) 567 [T] J. F. Bonner, Jr., report AECU-107, as quoted in 1953Kr16 [T] 1947BoAA P. Bouchez, Daudel, Muxart, J. Phys. et Radium 8 (1947) 336, as quoted in 1953Kr16

[T] 1949Se20 E. Segre, C. E. Wiegand, Phys. Rev. 75 (1949) 39; erratum Phys. Rev. 81 (1951) 284

[T] 1949Tu06 C. M. Turner, Phys. Rev. 76 (1949) 148 [P] 1949Wi13 R. M. Williamson, H. T. Richards, Phys. Rev. 76 (1949) 614 [P] 1951Di12 J. M. Dickson, T. C. Randle, Proc. Phys. Soc. (London) 64A (1951) 902 [P] 1953Kr16 J. J. Kraushaar, E. D. Wilson, K. T. Bainbridge, Phys. Rev. 90 (1953) 610 [T] 1956Bo36 P. Bouchez, J. Tobailem, J. Robert, R. Muxart, R. Mellet, P. Daudel, J. Phys. Rad. 17

(1956) 363 [T] 1957Wr37 H. W. Wright, E. I. Wyatt, S. A. Reynolds, W. S. Lyon, T. H. Handley, Nucl. Sci. Eng.

2 (1957) 427 [T] 1962Ta11 J. G. V. Taylor, J. S. Merritt, Can. J. Phys. 40 (1962) 926 [P] 1964Kr04 A. Kriester, Kernenergie 7 (1964) 748 [] 1965En01 J. B. A. England, B. L. Reece, Nucl. Phys. 72 (1965) 449 [T] 1966PoAA W. Poenitz, J. Nucl. Energy 20 (1966) 825 [P] 1969TaZX J. G. V. Taylor, J. S. Merritt, report AECL-3512 (1969) [P] 1970MuZU M. Mutterer, Neutron Standards and Flux Normalization 452, AEC Symp. Series 23

(1970) [P]

11



1970Jo21 H. W. Johlige, D. C. Aumann, H. J. Born, Phys. Rev. C2 (1970) 1616 [T] 1973Po10 W. P. Poenitz, A. Devolpi, Intern. J. Appl. Radiat. Isot. 24 (1973) 471 [P, P] 1974Cr05 P. J. Cressy, Jr., Nucl. Sci. Eng. 55 (1974) 450 [T] 1974Go26 I. W. Goodier, J. L. Makepeace, A. Williams, Intern. J. Appl. Radiat. Isot. 25 (1974)

373 [P], P] 1975La16 F. Lagoutine, J. Legrand, C. Bac, Intern. J. Appl. Radiat. Isot. 26 (1975) 131 [T] 1976Ba63 I. M. Band, M. B. Trzhaskovskaya, M. A. Listengarten, At. Data Nucl. Data Tables 18

(176) 433 [] 1982ChZF P. Christmas, report NBS-SP-626 (1982) 100 & 198 [T] 1982RuZV A. R. Rutledge, L. V. Smith, J. S. Merritt, report NBS-SP-626 (1982) 5 [T] 1983Da14 C. N. Davids, A. J. Elwyn, B. W. Filippone, S. B. Kaufman, K. E. Rehm, J. P. Schiffer,

Phys. Rev. C 28 (1983) 885 [P] 1983Ba15 D. P. Balamuth, L. Brown, T. E. Chapuran, J. Klein, R. Middleton, R. W. Zurmhle,

Phys. Rev. C 27 (1983) 1724 [P] 1983Do07 T. R. Donoghue, E. Sugarbaker, M. Wiescher, T. C. Rinckel, K. E. Sale, C. P. Browne,

E. D. Berners, R. W. Tarara, R. E. Warner, Phys. Rev. C 28 (1983) 875 [P] 1983Kn10 D. A. Knapp, A. B. McDonald, C. L. Bennett, Nucl. Phys. A411 (1983) 195 [P] 1983Ma34 G. J. Mathews, R. C. Haight, R. G. Lanier, R. M. White, Phys. Rev. C 28 (1983) 879

[P] 1983No03 E. B. Norman, T. E. Chupp, K. T. Lesko, J. L. Osborne, P. J. Grant, G. L. Woodruff,

Phys. Rev. C 27 (1983) 1728; erratum Phys. Rev. C 28 (1983) 1409 [P] 1984Ev01 H. C. Evans, I. P. Johnstone, J. R. Leslie, W. McLatchie, H.-B. Mak, P. Skensved, T. K.

Alexander, Can. J. Phys. 62 (1984) 1139 [P] 1984Fi10 S. A. Fisher, R. L. Hershberger, Nucl. Phys. A423 (1984) 121 [P] 1984Sk01 R. T. Shelton, R. W. Kavanagh, Nucl. Phys. A414 (1984) 141 [P] 1985ZiZY W. L. Zijp, report ECN-179 (1985) [averaging] 1992Ra09 M. U. Rajput, T. D. MacMahon, Nucl. Instr. Meth. A312 (1992) 289 [averaging] 1994Hu23 J. H. Hubbell, P. N. Trehan, Nirmal Singh, B. Chand, M. L. Garg, R. R. Garg, Surinder

Singh, S. Puri, J. Phys. Chem. Ref. Data 23 (1994) 339 [K] 1995Au04 G. Audi, A. H. Wapstra, Nucl.Phys. A595 (1995) 409 [Q] 1996Ja10 M. Jaeger, S. Wilmes, V. Klle, G. Staudt, P. Mohr, Phys. Rev. C 54 (1996) 423 [T] 1998Sc28 E. Schnfeld, Appl. Radiat. Isot. 49 (1998) 1353 [PL/PK] 1999Hu20 C.-H. Huh, Earth Plant. Sci. Lett. 171 (1999) 325 [T] 1999Ra12 A. Ray, P. Das, S. K. Saha, S. K. Das, B. Sethi, A. Mookerjee, C. Basu Chauduri, G.

Pari, Phys. Lett. B 455 (1999) 69 [T] 2000He14 R. G. Helmer, C. van der Leun, Nucl. Instr. Meth. A 450 (2000) 35 [E] 2000Hu20 C. A. Huh, L. G. Liu, Journal of Radioanalytical and Nuclear Chemistry 246 (2000) 229

[T] 2000Li21 L. G. Liu, C. A. Huh, Earth and Planetary Science Letters 180 (2000) 163 [T]

12

Comments on evaluation 11C

LNHB/V. Chist, M. M. B August 2002

11C Comments on evaluation of decay data by V. Chist and M. M. B

1) Decay Scheme 11C disintegrates by + emission (99.750(13)%) and electron capture (0.250(13)%) to the ground state of the stable nuclide 11B. 2) Nuclear Data The Q value (1982.5(9) keV) is from Audi and Wapstra evaluation (1995Au04), and has been calculated with the formula: Q = )1,(),( ZAMZAM , where M(A,Z) and M(A,Z-1) are the measured atomic masses of 11C and 11B, respectively. E+, calculated from this Q value (E+ = 960.5(9) keV), is in agreement with a weighted average value of 959.8(5) keV, which was calculated from measured values (see + Transition and Electron Capture Transition). The measured 11C half-life values (in minutes) are given below: T1/2

Reference Value (min) Smith (1941Sm11) 20.35 (8) Solomon (1941So01) 20.5 (6) Siegbahn (1944Si30) 20.0(4) Dickson (1951Di12) 20.0 (1) Kundu (1953Ku08) 20.74 (10) Barber (1955Ba63) 20.26 (10) Prokoshkin (1957Pr53) 20.8 (2) Arnell (1958Ar15) 20.11 (13) Kavanagh (1964Ka31) 20.34 (4) Patterson (1965Pa10) 20.8 (4) Awschalom (1969Aw02) 20.40 (4) Hogstrom (1973Ho43) 19.8 (8) Singh (1973SiYS) 20.0 (3) Azuelos (1975Az01) 20.382 (20) Behrens (1975Be28) 20.32 (12)

Evaluators calculated the weighted average of these 15 values using the Lweight program (version 3) as 20.369 min with an external uncertainty of 0.028 and a reduced 2 of 3.07. The value of Azuelos (1975Az01) has a relative statistical we ight of 54%. Evaluators rejected Siegbahns (1944Si30) value (quoted by Janecke (1960Ja12) and Raman (1978Ra21)), because they could not be find the article, and therefore no details were available on how Siegbahn obtained such a value. For the remaining 14 values,

13



the largest contribution to the weighted average comes from the value of Azuelos (1975Az01), with a relative statistical weight of 57%. The program Lweight 3 has increased the uncertainty of the 1975Az01 value from 0,02 to 0,0231 in order to reduced its relative statistical weight to 50%. The adopted value is the weighted average : 20.370 min, with an external uncertainty of 0.029 min. The reduced 2 is 3.24. + Transition and Electron capture transition For the K/+ ratio, the following values have been found in the literature:

Reference Value (10-3) Scobie (1957Sc02) 1.9(3) Campbell (1967Ca21) 2.30 (+0.14;-0.11)

+ and electron capture probabilities have been calculated using the most recent value of K/ + ratio measured by Campbell (19 67Ca21), PK/PEC = 0.9174(91) (See Section 2.2), and normalizing to a total probability (P+ + PEC) of 100%. This leads to P + = 99.750(13) % and PEC = 0.250(13), respectively. The uncertainties were calculated through their propagation on the above formulas. The experimental K/+ ratio of Campbell is close to the theoretical values: a) 2.222 10-3 calculated with LOGFT program; b) 2.00 10-3 calculated by Scobie (1957Sc02); c) 2.18 10-3 calculated by Campbell (1967Ca21); d) 2.46 10-3 calculated by Vatai (1968Va23); e) 2.316 10-3 given by Fitzpatrick (1973Fi13); f) 2.11 10-3 given by Bambynek (1977Ba49); Evaluators calculated a lg ft of 3.592 for this allowed transition. The value agrees with 3.599 suggested by Ajzenberg-Selove (1980Aj01, 1985Aj01 and 1990Aj01). The partial sub shell capture probabilities given in Section 2.2 were calculated using the program EC -Capture for an allowed transition. The weighted mean of the + end-point energy has been calculated (with the Lweight program, version 3) using the following measured values (in keV):

Reference Values (keV) Townsend (1940To03) 981(5)

Moore (1940Mo40) 1030(30) Siegbahn(1944Si30) 993(1) Richards (1950Ri07) 958(3) Wong (1954Wo19) 968(8)

Campbell (1967Ca21) 958.2(14) Fitzpatrick (1973Fi13) 960.2(10) Azuelos (1975Az01) 960.0(10) Behrens (1978Be28) 960.8(26) Raman (1978Ra21) 960.1(11)

The weighted average of these 10 values is 967 keV with an uncertainty of 2.6 keV and a reduced 2 of 97. The values of 1944Si30, 1973Fi13 and 1975Az01 have a relative weight of 21%. The Townsend (1940To03), Moore (1940Mo40), Siegbahn (1944Si30) and Wong (1954Wo19) values have been rejected by the Lweight program, based on the Chauvenets criterion. For the remaining 6 values, the largest contribution to the weighted average comes from the values of Fitzpatrick (1973Fi13) and Azuelos

14



(1975Az01), amounting to a statistical weight of 28%. The weighted average is 959.8 keV, with an internal uncertainty of 0,5 keV and a reduced 2 of 0,41. This value is in agreement with E+ (960.5(9) keV) deduced from the adopted Q value (1995Au04) in this evaluation. 3) Gamma-ray Emissions The annihilation radiation emission probability (I 511) is P+ (=99.750(13)%), multiplied by 2, without the correction factor for the annihilation-in-flight process in the medium. That is, I511 = 199.500(26)%. References 1940Mo40 B. L. Moore, Phys. Rev. 57 (1940) 355 [end-point energy]. 1940To03 A. A. Townsend, Proc. Roy. Soc. (London) 177 (1940) 357 [end-point energy]. 1941Sm11 J. H. C. Smith, D. B. Cowie, J. Appl. Phys.12 (1941) 78 [T1/2]. 1941So01 A. K. Solomon, Phys. Rev. 60 (1941) 279 [T1/2]. 1944Si30 Siegbahn, Arkiv Mat. Astron. Fysik 30B (1944) 20 [T1/2]. 1950Ri07 H. T. Richards, R. V. Smith, Phys. Rev. 77 (1950) 752 [end-point energy]. 1951Di12 J. M. Dickson, T. C. Randle, Proc. Phys. Soc. (London) 64A (1951) 902 [T1/2]. 1953Ku08 D. N. Kundu, T. W. Donaven, M. L. Pool, J. K. Long, Phys. Rev. 89 (1953) 1200 [T1/2]. 1954Wo19 C. Wong, Phys. Rev. 95 (1954) 765 [end-point energy]. 1955Ba63 W. C. Barber, W. D. George, D. D. Reagan, Phys. Rev. 98 (1955) 73 [T1/2]. 1957Pr53 - Iu. D. Prokoshkin, A. A. Tiapkin, Soviet. Phys. JETP 5 (1957) 148 [T1/2]. 1957Sc02 J. Scobie, G. M. Lewis, Phil. Mag. 2 (1957) 1089 [K/+ ratio]. 1958Ar15 S. E. Arnell, J. Dubois, O. Almen, Nucl. Phys. 6 (1958) 196 [T1/2]. 1960Ja12 V. J. Janecke, Z. F. Naturf. 15A (1960) 593 [T1/2]. 1964Ka31 T. M. Kavanagh, J. K. P. Lee, W. T. Link, Can. J. Phys. 42 (1964) 1429 [T1/2]. 1965Pa10 J. R. Patterson, J. M. Poate, E. W. Tutterton, B. A. Robson, Proc. Phys. Soc. (London) 86 (1965) 1297 [T1/2]. 1967Ca21 - J. L. Campbell, W. Leiper, K. W. Ledingham, R. W. P. Drever, Nucl. Phys. A96 (1967) 279 [K/+ ratio, end-point energy]. 1968Va23 E. Vatai, Proc. Conf. Electron Capture and higher order processes in Nucl. Decay 2 (1968) 71 [K/+ ratio]. 1969Aw02 - M. Awschalom, F. L. Larsen, W. Schimmerling, Nucl. Inst. Meth. 75 (1969) 93 [T1/2]. 1973Ho43 - K. R. Hogstrom, B. W. Mayes, L. Y. Lee, J. C. Allred, C. Goodman, G. S. Mutchler, C. R. Fletcher, G. C. Phillips, Nucl. Phys. A215 (1973) 598 [T1/2]. 1973SiYS J. Singh, Proc. Nucl. Phys. and Solid State Phys. Symp. 15B (1972) 1 [T1/2]. 1973Fi13 - M. L. Fitzpatrick, K. W. D. Ledingham, J. Y. Gourlay, J. G. Lynch, J. Phys. A6 (1973) 713 [K/+ ratio, end-point energy]. 1975Az01 - G. Azuelos, J. E. Kitching, K. Ramavataram, Phys. Rev. C12 (1975) 563 [T1/2, end-point energy]. 1975Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A248 (1975) 1 [T1/2, end point energy, Q, log ft]. 1975Be28 H. Behrens, M. Kobelt, L. Szybisz, W. G. Thies, Nucl. Phys. A246 (1975) 317 [T1/2, end-point energy] 1977Az01 - G. Azuelos, J. E. Kitching, K. Ramavataram, Phys. Rev. C15 (1977) 1847 [T1/2]. 1977Ba49 - W. Bambynek, H. Behrens, M. H. Chen, B. Crasemann, M. L. Fitzpatrick, K. W. D. Ledingham, H. Genz, M. Muttere, R. L. Intemann, Revs. Modern Phys. 49 (1977) 77 [Electron Capture]. 1978Ra21 - S. Raman, C. A. Houser, T. A. Walkiewicz, I. S. Towner, Atomic Data and Nucl. Data Tables 21 (1978) 567 [T1/2 , end point energy, Q, log ft]. 1980Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A336 (1980) 1 [T1/2 , Q, log ft]. 1985Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A433 (1985) 1 [T1/2 , Q, log ft]. 1990Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A506 (1990) 1 [T1/2 , Q, log ft, end-point energy]. 1995Au04 G. Audi, A.H. Wapstra, Nucl. Phys. A595 (1995) 409 [Q]. 2000Co21 Codata Group, Revs. Modern Phys. 72 (2000) 351 [m0c].

15

Comments on evaluation 13N

LNHB/V.Chist, M. M. B July 2002

13N Comments on evaluation of decay data by V. Chist and M. M. B

1) Decay Scheme 13N disintegrates by + emission (99,818 (13) %) and electron capture (0,182 (13) %) to the ground state of the stable nuclide 13C. 2) Nuclear Data The Q value (2220,44 (27) keV) is from the evaluation of Audi and Wapstra (1995Au04), and has been calculated using the formula: Q = )1,(),( ZAMZAM , where M(A,Z) and M(A,Z-1) are the measured atomic masses of 13N and 13C, respectively. The E+ deduced from this Q value (E + = 1198,45 (27) keV) agrees with the weighted average value of 1199,00 (36) keV, deduced from measured values (see + Transition and Electron Capture Transition). The measured 13N half-life values (in minutes) are given below: T1/2

Reference Value (min) Ward (1939Wa35) 9,93 (3) Siegbahn (1945Si02) 10,13 (10) Cook (1948Co05) 10,2 (1) Churchill(1953Ch34) 10,048 (32) Wilkinson (1955Wi43) 10,08 (4) Daniel (1957Da07) 9,960 (30) Deineko (1957De22) 10,02 (10) Norbeck (1957No17) 10,07 (6) Arnell (1958Ar15) 9,960 (30) King (1960Ki02) 9,93 (5) Janecke (1960Ja12) 9,965 (5) Ebrey (1965Eb03) 9,96 (2) Bormann (1965Bo42) 10,05 (5) Ritchie (1968Ri15) 9,963 (9) Singh (1973SiYS) 10,0 (5) Azuelos (1977Az01) 9,965(10) Katoh (1989Ka08) 9,962 (20)

The weighted average has been calculated using the Lweight computer program (version 3).

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The Siegbahn (1945Si02) and Cook (1948Co05) values have been shown to be outliers by the Lweight program, based on the Chauvenets criterion. For the remaining 15 statistically consistent values, the largest contribution to the weighted average comes from the value of Janecke (1960Ja12), with statistical weight of 54 %. The reduced-2 is 1,65. The adopted value is the weighted average : 9,9670 min, with an uncertainty of 0,0037min. 2.1) + Transition and Electron capture transition. The + and electron capture probabilities shown in Tables 2.1 and 2.2, respectively, have been deduced by using a K/ + ratio of (1,68 0,12).10-3 measured by Ledingham (1963Le06) and, normalizing to a total probability (P+ + PEC) of 100%. This experimental K/ + ratio is close to the following theoretical values: a) 1,864 10-3 calculated with LOGFT program; b) 1,939 10-3 calculated by Fitzpatrick (1973Fi13); c) 1,800 10-3 given by Bambynek (1977Ba49); d) 1,78 10-3 given by Ledingham (1963Le06). The uncertainties were estimated by standard error-propagation techniques. The lg ft value for + transition (3,654) has been calculated with the program LOGFT for an allowed transition. This value agrees with 3,637 suggested by Ajzenberg -Selove (1981Aj01, 1986Aj01 and 1991Aj01). The partial sub shell capture probabilities PK and PL were calculated for an allowed transition using the computer program EC-Capture. A weighted average (1199,0(4) keV) of the + end-point energy has been decuded (using the Lweight computer program, version 3) from the following measured values (in keV):

Reference Values (keV) Hornyak (1950Ho01) 1202 (5)

Grabowsky (1954Gr03) 1185 (25) Daniel (1957Da07) 1190 (3)

Fitzpatrick (1973Fi13) 1198,5(9) Raman (1978Ra21) 1198,7 (4)

The largest contribution (with an statistical weight of 81%) to the weighted average of these 5 values comes from the value of Raman (1978Ra21). The weighted average is 1199,00 keV, with an internal uncertainty of 0,36 and a reduced -2 of 2,2. This value agrees with E+ (1198,45(27) keV), which was deduced from the adopted Q value (1995Au04) in this evaluation. 3) Gamma-ray Emissions The annihilation radiation emission intensity (I 511) is P+ ( = 99,818 (13)), multiplied by 2, wi thout the correction factor for the annihilation-in-flight processus in the medium. That is, I511 = 199,636 (26) %. 4) Atomic Data Atomic K-fluorescence yield (K) is from Bambynek (1984Ba01).

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References 1939Wa35 W. Ward, Proc. Cambridge Phil. Soc. 35 (1939) 523 [T1/2]. 1945Si02 S. Siegbahn, Arkiv F. Art. Mat. Fys. 32A (1945) 9 [T1/2]. 1948Co05 C. S. Cook, L. M. Langer, C. Price Jr., M. B. Sampson, Phys. Rev. 74 (1948) 502 [T1/2]. 1950Ho01 B. Hornyak, Phys. Rev. 77 (1950) 160 [end-point energy]. 1952Aj01 F. Ajzenberg, Rev. Mod. Phys. 24 (1952) 321 [T1/2 , end-point energy, log ft]. 1953Ch34 J. L. W. Churchill, W. M. Jones, S. E. Hunt, Nature 172 (1953) 460 [T1/2]. 1954Gr03 - N. Grabowsky, Bull. Acad. Pol. Sci. 2 (1954) 379 [end-point energy]. 1955Wi43 D. H. Wilkinson, Phys. Rev. 100 (1955) 32 [T1/2]. 1955Aj01 F. Ajzenberg, Rev. Mod. Phys. 27 (1955) 27 [T1/2 , end-point energy, log ft]. 1957No17 E. Norbeck Jr., C. S. Littlejohn, Phys. Rev. 108 (1957) 754 [T1/2]. 1957De22 S. Deineko, A. Ia. Taranov, A. K. Valter, Sov. Phys. - JETP 5 (1957) 201 [T1/2]. 1957Da07 - H. Daniel, U. Schmidt-Rohr, Z. Naturforsch 12A (1957) 750 [T1/2 ]. 1958Ar15 S. E. Arnell, J. Dubois, O. Almen, Nucl. Phys. 6 (1958) 196 [T1/2]. 1958St30 D. Strominger, J. L. Hollander, G. T. Seaborg, Rev. Mod. Phys. 30 (1958) 585 [T1/2 , end point energy, Q, log ft]. 1960Ki02 J. D. King, R. N. H. Haslam, R. W. Parsons, Can. J. Phys. 38 (1960) 231 [T1/2]. 1960Ja12 - V. J. Janecke, Z. F. Naturf. 15A (1960) 593 [T1/2]. 1963Le06 - K. W. D. Ledingham, J. A. Payne, R. W. P. Drever, Proc. Int. Conf. Role of Atomic Electrons in Nuclear Transformations 2 (1963) 359 [K/+ ratio]. 1965Eb03 T. G. Ebrey, P. R. Gray, Nucl. Phys. 61 (1965) 479 [T1/2]. 1965Bo42 M. Bormann, E. Fretwurst, P. Schehka, G. Wrege, Nucl. Phys. 63 (1965) 438 [T1/2]. 1968Va23 E. Vatai, Proc. Conf. Electron Capture and higher order processes in Nucl. Decay 2 (1968) 71 [K/+ ratio]. 1968Ri15 A. I. M. Ritchie, Nucl. Inst. Meth. 64 (1968) 181 [T1/2]. 1973SiYS J. Singh, Proc. Nucl. Phys. and Solid State Phys. Symp. 15B (1972) 1 [T1/2]. 1973Fi13 - M. L. Fitzpatrick, K. W. D. Ledingham, J. Y. Gourlay, J. G. Lynch, J. Phys. A6 (1973) 713 [K/+ ratio]. 1976Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A268 (1976) 1 [T1/2 , Q, log ft]. 1977Az01 - G. Azuelos, J. E. Kitching, K. Ramavataram, Phys. Rev. C15 (1977) 1847 [T1/2]. 1977Ba49 - W. Bambynek, H. Behrens, M. H. Chen, B. Crasemann, M. L. Fitzpatrick, K. W. D. Ledingham, H. Genz, M. Muttere, R. L. Intemann, Revs. Modern Phys. 49 (1977) 77 [Electron Capture]. 1978Ra21 - S. Raman, C. A. Houser, T. A. Walkiewicz, I. S. Towner, Atomic Data and Nucl. Data Tables 21 (1978) 567 [T1/2 , end point energy, Q, log ft]. 1981Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A360 (1981) 1 [T1/2 , Q, log ft]. 1984Ba01 W. Bambynek, Proc. X-ray and Inner-Shell Processes in Atoms, Molecules and Solids, Leipzig, Aug. 20-23, 1984. Edited by A. Meisel [Atomic Data] 1986Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A449 (1986) 1 [T1/2 , Q, log ft]. 1989Ka08 T. Katoh, K. Kawade, H. Yamamoto, JAERI-M-089-083 (1989) [T1/2] 1991Aj01 - F. Ajzenberg-Selove, Nucl. Phys. A523 (1991) 1 [T1/2 , Q, log ft]. 1995Au04 G. Audi, A.H. Wapstra, Nucl. Phys. A595 (1995) 409 [Q]. 2000Co21 Codata Group, Revs. Modern Phys. 72 (2000) 351 [m0c].

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LNHB/M.M.B, KRI/V.Chechev Jan. 2012

14C - Comments on evaluation of decay data by M.M. B and V.P. Chechev

This evaluation was completed in 1998, it was updated in January 2012 to include the most recent Q() update. The literature available by this date was included. Nuclear Data Half-life In literature there are many measurements of the 14C half-life dating from 1946 to 1954 (Table 1). Mann et al. (1961) discussed the problem of spread of these measurement results from 4 700 to 7 200 years. They connect the divergence with very low enrichment of 14C (a few percentages) and a large systematic uncertainty arose from retention of a small quantity of carbon dioxide with a high specific activity during a gas dilution phase. Therefore, following Holden (1990Ho28) who evaluated the 14C half-life in 1990, we have omitted the measurement results before 1961 and considered only later measurements (Table 2). In all the latter works the number of 14C atoms has been determined by the mass-spectrometric method and the counting rate was measured by different methods as shown in Table 1. Table 1: Results of 14C half-life measurements NSR keynumber Half-life of 14C,

years Method

1946Re10 4 700 (400) SA: GM; MS 1948No02 5 100 (200) - " - 1948Ya02 7 200 (500) - " - 1949Ha52 6 360 (200) - " - 1949Jo07 5 589 (75) - " - 1950En59 5 580 (90) - " - 1950Mi10 6 360 (190) - " - 1950Mi10 5 513 (165) SA: PC ; MS 1951Ma30 5 370 (200) SA: IC ; MS 1952Je11 6 030 SA: GM ; gas density 1954Ca41 5 900 (250) SA: Cal ; gas density 1961Ma32 5 760 (50) SA: PC ; MS 1961Wa16 5 780 (65) SA: PC ; MS 1962Ol14 5 680 (40) SA: PC ; MS 1964Hu09 5 745 (50) SA: PC ; MS. 1961Ma32 value revised 1968Be47 5 660 (30) SA: PC(GM) ; MS 1968Re13 + 1972Em01

5 736 (56) SA: LS ; MS

Usual designations: SA - method of radionuclide specific activity determination, by mean of Geiger-Mller counter (GM), proportional counter (PC), calorimeter (Cal), ionization chamber (IC) or liquid scintillation counter (LS); MS - determination of the number of atoms by the mass-spectrometric method.

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Table 2: Selected measurement results and recommended value of 14C half-life Year Half-life of 14C, Reference a NSR keynumber 1961 5 780 (65) 1961Wa16 1962 5 680 (40) 1962Ol14 1964 5 745 (50) 1964Hu09 1968 5 660 (30) 1968Be47 1968 5 736 (56) 1968Re13/1972Em01 2 /n-1 = 1,2 ; critical 2 = 3,3 Weighted average 5 697 (21) a Unweighted average 5 720 (22) a Recommended value 5 700 (30) a The adopted value of the 14C half-life is the weighted average of the five results listed in Table 2. Since they were all obtained by the same method of the specific activity measurement, the final uncertainty is taken as the lowest experimental uncertainty of the data set. It should be noticed that Holden gave a similar evaluation of 14C, T1/2 (5 715 30 years), but he adopted the unweighted average of the same measurement results with addition to them of the average of three values obtained in 1949-1950. From an analysis of fossil corals whose ages were determined via 234Th/234U/238U dating, a 14C half-life of 6 030 a should be expected (2007Ch**). A re-determination of the 14C half-life is required to improve radiocarbon-based researches. Decay Energy and Characteristics of Electron Emission (-) The 14C beta decay to the ground state level of 14Ni is expected to be allowed (0+ 1+). However it has been shown deviations in the shape of the 14C beta spectrum (2000Ku25, 1995Wi20). A summary of measured and predicted spectra is given in 2000Ku25. The maximum energy of the spectrum was deduced from the results of measurements, as listed below. Table 3: Measured end-point energy, E0. Reference E0 (keV) uc Remarks Cook (1948Co10) 156,3 10 Forster (1954Fo*) 155 1 Smith (1975Sm02) 156,476 0,005 rf mass spectrometer Sur (1991Su09) 155,74 0,08 14C-doped Ge detector, taking into account

anomalies in the spectrum Wietfeldt (1995Wi20) 155,95 0,22 14C-doped Ge detector, taking into account

anomalies in the spectrum Kuzminov (2000Ku25) 156,27 0,14 Wall-less proportional counter, taking into

account anomalies in the spectrum It is noteworthy that the value reported by Smith (1975Sm02) is much more precise but also discrepant with the other results obtained by different methods. The set of the four most precise values is discrepant with a 2 /n-1 = 17. Then the uncertainty of the Smiths value has been increased to 0,066 in order to reduce its weight to 50 %. The resulting weighted average with an expanded uncertainty to cover the most precise result is: 156,18 (30) keV.

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This value is considerably less precise than the recommended value of 156,476 (4) keV given in Audi et al. (2003Au03). On one hand, the weighted mean is only limited to values following 14Cdecay and one value that comes from a direct mass-difference measurements using the rf technique; when the value recommended by Audi et al. (2003Au03/2011AuZZ) is deduced from the mass differences between 14C and 14N, determined using a robust least-squares procedure. On the other hand, in that case the whole "robust least-squares procedure" in 2003Au03/2011AuZZ is dominated by the single ultra-precise mass-spectrometric value. And this exact 14C - 14N mass difference affects other masses, and not vice versa. In this evaluation we will accept the Audi et al. recommendation, while following the Wietfelds conclusion (1995Wi20): We feel there is a significant problem in the 14C Q value and we hope that this will be resolved by future experiments. The average energy per disintegration has been calculated, expecting an allowed form of -spectrum, by using the program BetaShape (2012Mo**) which includes the calculations of exchange effects. E max (keV) Emean (keV) 156,18 (30) 49,1 (3) 156,476 (4) 49,16 (1) References 1946Re10 A.F. Reid, J.R. Dunning. Phys.Rev. 70, (1946) 431 [T1/2] 1948Co10 C.S. Cook, L.M. Langer, H.C. Price, Jr. Phys.Rev. 74 (1948) 548 [Q] 1948No02 L.D. Norris, M.G. Inghram. Phys.Rev. 73 (1948) 350 [T1/2] 1948Ya02 L. Yaffe, J.M. Grunlund. Phys.Rev. 74 (1948) 696 [T1/2] 1949Ha52 R.C. Hawkings, R.F. Hunter, W.B. Mann, W.H. Stephens. Can.J.Res. 27B (1949) 545 [T1/2] 1949Jo07 W.M. Jones. Phys.Rev

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