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Slide 1
Nuclear Reaction and Decay Data for Medium Energy Radionuclide Production
Jonathan W. Engle
Los Alamos National Laboratory, LA-UR 15-23573
Thursday, May 28th, 2015
Slide 2
Medium-Energy Radionuclide Production Context at LANL IPF
IPF at LANSCE
Beam Stop Line D
Line X
Line A 800 MeV Side Coupled Cavity Linac
805 MHz H+
H- Drift Tube Linac
201.25 MHz
100 MeV Transition Region
750 keV
H+
H-
H-
Proton Injectors
100-MeV IPF
SCCL is 90% of accelerator length
Proton Storage Ring
Weapons Neutron Research Facility
Manuel Lujan, Jr. Neutron Scattering Center
Unclassified
Slide 3
Medium-Energy Radionuclide Production Context at LANL IPF
(p,xnyp) (p,αxn) (p,αxn)
(p,xn) (p,xn) (p,xn)
High Energy (93-70 MeV)
Medium Energy (65-40 MeV)
Low Energy (31-0 Mev)
3 Stack Target Irradiation 100 MeV H+
(240 µA limit)
Slide 4
Radionuclides of Interest at LANL Red for those with nuclear data being actively or recently pursued.
Isotope Half-life Main Use 82Sr 25.5 d Parent of 82Rb used in cardiac perfusion studies with PET 68Ge 270 d Parent of 68Ga being tested for diverse PET applications 22Na 2.6 a PET isotope used as a tracer and sources material 32Si 153 a Environmental tracer; produced in partnership w/ TRIUMF 73As 80.3 d Tracer for toxicology studies
109Cd 462.6 d Source for X-ray fluorescence 225Ac 10 d Alpha emitter used in cancer therapy clinical trials
186gRe 90.6 h Bone pain palliation, cancer therapy 44Ti 58.9 a Generator for PET isotope 44Sc
236Np 1.5 105 a Standard for Np quantification by IDMS 119Sb 38.5 h Auger emitter for cancer therapy
Slide 5
Summary
• Nuclear Excitation Functions – Targeted measurements in the context of global isotope/data needs and existing production facilities
§ Needed to predict Yield and Impurities and to guide Target Design § Needed to resolve discrepancies § Useful for V&V of codes and nuclear models
• The necessary quality and breadth of capabilities § Accuracy in Standard Foil Stack Activation experiments
- Energy and distribution, intensity… Analyzing magnets, Faraday cups - Target characterization
– Target preparation and pre/post-irradiation characterization – Signal attribution due to overlapping gammas
§ Charged and neutral particles
• Nuclear Decay Data
Slide 6
To Predict Yields and Impurities
232Th(p,x)225Ac 232Th(p,x)227Ac
Slide 7
To Predict Yields and Impurities
232Th(p,x)225Ac 232Th(p,x)227Ac
Slide 8
To Predict Yields and Impurities
0
5
10
15
20
25
30
35
40 60 80 100 120 140 160 180 200
Cros
s Sec
tion
(mb)
Energy (MeV)
Th-232(p,x)Ac-226ABLA+INCLCEM03.04BertiniTitarenko et al, 2003Gauvin et al, 1963This Work
0
5
10
15
20
25
30
35
40
20 40 60 80 100 120 140 160 180 200
Cros
s Sec
tion
(mb)
Energy (MeV)
Th-232(p,x)Ac-227ABLA+INCLCEM03.04BertiniErmolaev et al. 2012, αErmolaev et al. 2012, 159 keV γErmolaev et al. 2012, 100 keV γGauvin et al., 1963Lefort et al., 1961This Work
0
1
2
3
4
5
6
40 60 80 100 120 140 160 180 200
Cros
s Sec
tion
(mb)
Energy (MeV)
Th-232(p,x)Ce-139ABLA+INCLCEM03.04BertiniThis Work
0
10
20
30
40
50
60
40 60 80 100 120 140 160 180 200
Cro
ss S
ectio
n (m
b)
Energy (MeV)
Th-232(p,x)Ce-141 ABLA+INCLCEM03.04
BertiniTitarenko et al, 2003
Holub and Yaffe, 1973This Work
0
5
10
15
20
25
30
35
40
40 60 80 100 120 140 160 180 200
Cros
s Sec
tion
(mb)
Energy (MeV)
Th-232(p,x)Ce-143
ABLA+INCLCEM03.04
BertiniTitarenko et al, 2003
Holub and Yaffe, 1973This Work
0
2
4
6
8
10
12
40 60 80 100 120 140 160 180 200
Cros
s Sec
tion
(mb)
Energy (MeV)
Th-232(p,x)La-140
ABLA+INCLCEM03.04
BertiniTitarenko et al, 2003
Holub and Yaffe, 1973This Work
0
10
20
30
40
50
40 60 80 100 120 140 160 180 200
Cros
s Sec
tion
(mb)
Energy (MeV)
Th-232(p,x)Ba-140
ABLA+INCLCEM03.04
BertiniTitarenko et al, 2003
Holub and Yaffe, 1973Duijvestijn et al, 1999
This Work
226Ac 227Ac
139Ce 141Ce 143Ce
140La
140Ba J.W. Engle et al. Phys. Rev. C 88 (2013) 014604
J.W. Engle et al. (accepted to Radiochimica Acta)
Slide 9
To Guide Target Design Example: 75As(p,4n)72Se, natBr(p,x)72Se
Slide 9
0
20
40
60
80
100
120
140
160
30 50 70 90 Proton energy [MeV]
1979, T. Nozaki+
1988, A. Mushtaq+
75As(p,4n)72Se
0
2
4
6
8
10
12
14
10 30 50 70 90
Cro
ss se
ctio
n [m
b]
Proton energy [MeV]
2001,M.Fassbender+
2002,D.deVilliers+
natBr(p,x)72Se
Slide 10
New Measurements are Also Needed to Resolve Discrepancies
natSb(p,x)119gSb natSb(p,x)119mSb
Slide 11
Data as a Standard for V&V of Nuclear Codes
0.1
1
10
1007 Bei
46 Sci(m
+g)
48 Sci
59 Fec
74 Asi76 Asi77 Brc
82 Bri(m
+g)
86 Rbi(m
+g)
87 Yc
87m Y
c88 Y
i91 Sr
c95 Nb
i(m+g
)95 Tc
c*95 Zr
c96 Nb
i96 Tc
i(m+g
)99 M
oc
99m Tc
i(m)
100 Pd
c10
0 Rhc
103 Ru
c
Cros
s Sec
tion
(mb)
800 MeV p + 232Th
(a)This WorkTitarenko et al., 2003CEM03.03BertiniABLA+INCL
Slide 12
Data as a Standard for V&V of Nuclear Codes
0.1
1
10
100
7 Bei46 Sc
i(m+g
)48 Sc
i59 Fe
c74 Asi76 Asi77 Brc
82 Bri(m
+g)
86 Rbi(m
+g)
87 Yc
87m Y
c88 Y
i91 Sr
c95 Nb
i(m+g
)95 Tc
c*95 Zr
c96 Nb
i96 Tc
i(m+g
)99 M
oc
99m Tc
i(m)
100 Pd
c10
0 Rhc
103 Ru
c
Cros
s Sec
tion
(mb)
800 MeV p + 232Th
(a)This WorkTitarenko et al., 2003CEM03.03BertiniABLA+INCL
Assumed accuracy in code predictions for charged particle-induced reactions: • Magnitude: Factors of 1-5 • Structure: Within 10 MeV
Useful measurements will improve on this.
Slide 13
The Standard Stacked Foil Activation Method
1. Activation of well-characterized thin samples
2. Quantification of produced radioactive residuals
3. Calculation of reaction probability
Slide 14
The Standard Stacked Foil Activation Method
• Driving, Reported Uncertainties at Present: – Incident particle flux during measurement: 4-12% – HPGe Assay: 3-5% efficiency calibration. 1-3% peak fitting. – Characterization of atomic density of irradiated sample: 1-?%
(challenging when not using metallic foils)
– Peak deconvolution / Radionuclide identification: a problematic, systematic source of misattribution error
Combined Uncertainty is generally >6%.
Slide 15
Particle Intensity
• Commonly tracked with monitor reactions, which lend their own uncertainty
27Al(p,x)24Na
Slide 16
A solution: Faraday Cups
• Of course they have their own challenges: – secondary electron suppression, – target electrical insulation, – particle and flux dependences are not
always simple
• Alternative real-time, verifiable particle flux monitors
– Offline-Faraday Cup calibrated SEEM or LEM
Slide 17
Primary Beam Energy
• Energy degradation has a limited effective range, – Commonly “verified” by monitor foils giving reactions with known
thresholds (indirect measurement), – or calculated by established codes (computational)
0
5
10
15
20
25
30
35
40
10 12 14 16 18 20 22 24
TTL ra7o
Proton energy [MeV]
181/186g
181/182g
Slide 18
Tunable Beam Energies, Analyzing Magnets
Slide 19
Target Characterization
• Some measurements are avoided because of the challenge of characterizing targets (e.g.,72Se) – We need better ways to prepare them and measured mg/cm2
– e.g.: XRF?
Sb Kα Cu Kα
• Kα map shows very low intensity all around the edges of the foil Intensity decreases by a factor of ~2 in the green region relative to the blue
• The unexpected presence of Cu lines reveals estimated 40-50% contamination from Cu
Slide 20
Residual Quantification
• At higher energies, or for more massive target nuclei, spectral analysis is challenging
0
2
4
6
8
10
12
0 500 1000 1500 2000
log(
Coun
ts)
Energy (keV)
Example Spectrum of 800 MeV p + Th-232
Slide 21
Identification and Quantification of Residuals by Gamma-Ray Spectrometry
Slide 21 Slide 21
102
103
0 10 20 30 40 50 60 70 80
165.85 keV, 79.9%
cps
in P
hoto
peak
Time (d since EoB)
y = m1*exp(-ln(2)/137.64*x)ErrorValue
2.1422448.38m1 NA9635.4Chisq
NA0.85844R2
101
102
103
104
0 5 10 15 20 25 30 35 40
534.4 keV, 67.6%199.2 keV, 41.5%1222 keV, 31.3%
cps i
n Ph
otop
eak
Time (d since EoB)
y = m1*exp(-ln(2)/5.35*x)ErrorValue
10.4256710.7m1 NA17562Chisq
NA0.99962R2
Peak areas extracted from multiple recorded spectra
Decay of one gamma line followed over time to determine EOB activity
Decay of three gamma lines over time, providing three independent EOB activity measurements
One analysis cycle produces a single cross section data point
Slide 22
What is possible
10
100
1000
104
0 20 40 60 80 100 120
199Au, 117Sb, 123Te, 123I, 226Ac, and 117mSn Decay Curves
158 keV
cps
in P
hoto
peak
t (d since EoB)
y = m1*exp(-ln(2)/3.139*x)+m...ErrorValue
45.849618.47Au1996170.43.1092e+5Sb117
0.5868366.996Te123639.5716729I123233.57765.18Ac226
7.333870.33Sn117mNA106.69Chisq
NA0.99942R2
Slide 23
Neutral Particles
• Neutrons (the very fast ones) • Also for gammas
0.01
0.1
1
10 100
Cro
ss S
ectio
n (b
arns
)
Energy (MeV)
Zn-68(n,x)Cu-67
Experimental DataTENDL 2012TENDL 2011TENDL 2010JEFF-3.2
0.01
0.1
1
10 100
Cros
s Sec
tion
(bar
ns)
Energy (MeV)
Zn-67(n,p)Cu-67 Experimental DataTENDL 2012ENDF/B-VII.1ROSFOND 2010
Slide 24
Data to Buttress Capability Development at New Facilities
Slide 25
Nuclear Decay Data – An example
Measured BR Source
776.50 keV gamma of 82Rb
13.4 ± 0.5 % H.-W. Muller 1987 (extensively used)
15.08 ± 0.16 % J.K. Tuli 2003 & NNDC 14.93 ± 0.37% C.J. Gross et al., 2012
Slide 25
Slide 26
Thank you for your attention
Slide 27
Related initiatives Engagement in IAEA data evaluation efforts
• Cross section measurement effort gained national and international attention
• Invited to participate in an IAEA Consultants’ Meeting in 2011
• Follow-up invitation to participate in a 3 year IAEA Coordinated Research Project starting in 2012 (11 countries represented)
• First of three Research Coordination Meetings occurred in Dec 2012
• Summary Report published in February 2013