Experiments at European “small-scale” facilities

M. Heil, FZ Karlsruhe

Challenges and Advanced Research In Nuclear Astrophysics

FIRST CARINA WORKSHOP, Parador d'Aiguablava (Girona), Spain, 8-10 June, 2005

Background:Carina Nebula

Small-scale facilitiesAtomki/Debrecen E. Somorjai somorjai@atomki.huBochum C. Rolfs rolfs@EP3.ruhr-uni-bochum.deBordeaux B. Haas haas@cenbg.in2p3.frPTB Braunschweig U. Giesen Ulrich.Giesen@ptb.deCatania C. Spitaleri spitaleri@lns.infn.itTU Darmstadt A. Zilges zilges@ikp.tu-darmstadt.deDemokritos S. Harissopulos sharisop@mail.demokritos.grFZK F. Kaeppeler franz.kaeppeler@ik.fzk.deGeel/ Gelina C. Wagemans Cyrillus.WAGEMANS@cec.eu.intGran Sasso C. Broggini carlo.broggini@pd.infn.itTU Munich G. Korschinek Gunther.Korschinek@ph.tum.deNapoli F. Terrasi Filippo.Terrasi@na.infn.itOrsay A. Coc coc@csnsm.in2p3.frOslo M. Guttormsen magne.guttormsen@fys.uio.noRez V. Kroha kroha@ujf.cas.czRossendorf A. Wagner a.wagner@fz-rossendorf.deUni. Vienna W. Kutschera Walter.Kutschera@univie.ac.atWeizmann Inst. M. Hass michael.hass@weizmann.ac.ilETH Zurich M. Suter martin.suter@phys.ethz.chPSI Villingen D. Schumann dorothea.schumann@psi.chn_TOF A. Mengoni alberto.mengoni@cern.chTU Berlin K. Zcerski czerski@kalium.physik.tu-berlin.de

Outline

Structure:• Overview of the facility (14 institutes out of 22)

(Equipment, main research interest, contact person)• Research highlights• Future developments

Groups:• Low energy beam facilities• Neutron facilities• γ-ray production facility• Accelerator mass spectroscopy• Preparation of radioavtive samples

Low energy beam facilities

CNO cycle

Electron screening

pp-chain

Solar neutrinos

Extrapolation Measurements

Indirect methods: ANC, THM

S

LUNA

Location: Gran Sasso, Italy

Facility/Equipment: Underground laboratory with two acceleratorsLUNA1: 50 kV and LUNA2: 400 kV, Imax=1 mA

Main interest: Low background measurements of small reaction rates in the Gamow window

Contact person: Carlo Broggini e-mail: carlo.broggini@pd.infn.it

p + p → d + e+ + νe

d + p → 3He + γ

3He +3He → α + 2p 3He +4He → 7Be + γ

7Be+e-→ 7Li + γ +νe7Be + p → 8B + γ

7Li + p → α + α 8B→ 2α + e++ νe

84.7 % 13.8 %

13.78 % 0.02 %

pp chain

measured 2004-2005

Main activities:• Cross section measurements of fusion reaction relevant for the pp chain• Other nuclear burning reactions in stars 15N(p,γ)15O

Weizmann Institute

Location: Rohovot, Israel

Facility/Equipment: The 3 MV Van de Graaff accelerator, beams of p,d,3He and 4He of energies from ~300 keV to 3 MeV. A 14 MV heavy ion Koffler Pellettron accelerator, mostly used for AMS.

Main interest: Cross section measurements of solar fusion reactions Accelerator Mass Spectroscopy (AMS)

Contact person: M. Hass e-mail: michael.hass@weizmann.ac.ilM. Paul e-mail: PAUL@vms.HUJI.AC.IL

Weizmann Institute

• Solar fusion reactions of current relevance to solar-neutrinos and Beg Bang Nucleosynthesis. Examples: 7Be(p,γ)8B and 3He(4He,γ)7Be

• AMS with the 14 MV Pellettron accelerator. Example: 4He(40Ca,γ)44Ti

• The Soreq high intensity linac - SARAF This is a new facility being now constructed at the Soreq Research Center. It is a 2 mA, 40 MeV, p, d and 4He accelerator. It will serve as an excellent "driver" accelerator and there are plans to obtain several light-A RNB's for astrophysics.It can also serve as a high intense neutron source via the 7Li(p,n)7Be reaction.

40 MeV x 2 mA p/d RF SC linac

Location: Berlin, Germany

Facility/Equipment: Electrostatic acceleratorMaximal energy: 180 keVBeam current (protons): < 300 μALong-term stability ~ 10 V, Energy definition ~ 10 eV

Main interest: Deuteron induced reactions on light nuclei at very low energies forprimordial nucleosynthesis.Experimental and theoretical studies of the electron screening effect in metallic environments, consequences for astrophysical plasmas.

Contact person: K. Czerski, e-mail: czerski@kalium.physik.tu-berlin.de

TU Berlin

Discovery of the enhanced electron screening in metallic environments

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Comparison between the experimental normalized yield of thereaction 2H(d,p)3H in Pd and theoretical calculations. In absenceof the electron screening the yield should be energy independentand equal to unity.

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Comparison between experimental and theoretical screeningenergies. The theoretical calculations within the self-consistentdielectric function theory describe correctly the observedmaterial dependence fail, however, the absolute values.

K. Czerski, A. Huke, A. Biller, P. Heide, M. Hoeft and G. Ruprecht, Europhys. Lett. 54 (2001) 449K. Czerski, A. Huke, P. Heide, G. Ruprecht, G. Schiwietz, Nucl. Instr. Meth. B 193 (2002) 183K. Czerski, A. Huke, P. Heide, G. Ruprecht, Europhys. Lett. 68 (2004) 363

TU Berlin

Location: Orsay, France

Facility/Equipment: Electrostatic accelerator PAPAP, Umax=200kV, 1 mA protons with

superconducting solenoid2 MV tandem ARAMIS for implantation and isotopic separation, mainly

used for solid state physics. 15 MV tandem (IPNO)

Main interest: Study of low energy resonances and reaction rates with PAPAP.Transfer reactions and inelastic cross section measurements at IPNO

Contact person: A. Coc, e-mail: coc@csnsm.in2p3.frF. Hammache, e-mail: hammache@ipno.in2p3.fr

Orsay (CSNSM + IPNO)

Orsay

• Direct measurement of 7Be(p,γ)8B (solar neutrinos).

• Direct measurement of resonance at 180 keV for 17O(p,α) and (p,γ) for nova gamma ray emission. Because of lack of technical staff, PAPAP is now virtually closed.

• One of our main ongoing projects is the study of the astrophysical reaction 13C(α,n)16O. A measurement by means of the transfer reaction 13C(7Li,t)17O is scheduled at the Tandem of Orsay for October 2005.

Location: Catania, Italy

Facility/Equipment: Superconducting Cyclotron15 MV Tandem acceleratorVarious detector systems: CHIMERA, MAGNEX, MEDIAIn future: RIB facility EXCYT

Main interest: Indirect methods, e.g. THM, transfer reactions

Contact person: C. Spitaleri e-mail: spitaleri@lns.infn.it

Catania

The reaction 99Be(p,Be(p,αα))66LiLi studied via the Trojan Horse method (THM)applied to the 22H(H(99Be,Be,αα66Li)n reactionLi)n reaction

Experiment carried on at LNS

Febbraio 2003 (Tandem & Camera2000);Ebeam(9Be)=22 MeV & Ibeam(9Be)=2-5 nA;

THMDirectdata

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Catania - THM

INFN - Laboratori Nazionali del Sud

EXCYT LayoutCatania – EXCYT Layout

The facility is completely assembled, optically aligned, and vacuum tested up to the tandem entrance

Facility commissioning and first experiments in 2005.

The first beams produced by EXCYT will be: 8Li and 9Li for nuclear astrophysics and experiments with MAGNEX. The expected intensities are respectively 2×106 pps and 2×105 pps at 400 W beam power.

In 2006 the production of new RIBs (oxygen, fluorine and chlorine) will be decided according to the experiment proposals.

EXCYT status

Location: Rez, Czech Republic

Facility/Equipment: Cyclotron: p, d, 3He, 4He up to 50 MeV4 MV Tandem accelerator for heavy ionsAMOS: achromatic magnetooptical system

for „zero“-angle measurements (<20°)Target chamber for angular cross sections measurementsΔE – E telescopes with semiconductor detectorsNeutron generators NG 1 and NG 2 for activation experimentsNeutron spectrometers

Main interest: Indirect methods to study direct capture rates (ANC method)

Contact person: V. Kroha, e-mail: kroha@ujf.cas.cz

Řež

Řež• Verification of the method:

16O(3He,d)17F reaction to determine 16O(p,γ)17F. An accuracy better than 8 – 9 % was found

• The 14N(3He,d)15O / 14N(p,γ)15O• 15N(p,γ)16O and 18O(p,γ)19F using ANCs from

15N(3He,d)16O and 18O(3He,d)19F reactions

• Astrophysical activities based on the interpretation of the ANC method will continue with the aim to verify its validity also for the radiative α-particle capture which cause the nucleosynthesis during helium burning in stellar environment.

• The other indirect technique, Trojan – Horse method, was developed in the past by Catania group. Using a 3He-beam of our cyclotron and in cooperation with LNS, we will study the possibility of absolutization of this method by its combination with ANC. This would represent a new trend in the development of indirect methods in nuclear astrophysics.

Neutron facilities

AGB stars

p process

s process

r process

Massive stars

Location: Karlsruhe, Germany

Facility/Equipment: 3.7 MV Van de Graaff accelerator Operation frequency: 125 kHz – 5 MHzDC beams up to 200 μAMaximum neutron rate: 2.0·109 1/s in DC mode for activation4π BaF2 γ-calorimeter, two Clover HPGe detectors

Main interest: Measurements of neutron capture cross sections. Charged particle reactions at low energies.

Contact person: F. Kaeppeler, e-mail: franz.kaeppeler@ik.fzk.de

FZ Karlsruhe

FZ Karlsruhe

sample

γ

γ

γ

Pb neutron target

p-beamγ

collimatedn-beam

Neutron capture measurements with the TOF setup on heavy nuclei (rare earth region)

FZ Karlsruhe

• New: 18O(p,n)18F reaction: kT=5 keV, Φn = 1·105 s-1

• 7Li(p,n)7Be reaction: kT=25 keV, Φn = 3·109 s-1

Activation technique using quasi-stellar spectra

Location: Geel, Belgium

Facility/Equipment: Electron Linac for production of neutrons via bremsstrahlung. Operation frequency: 40 Hz – 800 HzAverage current: 75 μAAverage electron energy: 100 MeVMean power: 7.5 kWMaximum neutron rate: 2.5·10131/s at 800 Hz and 1 ns pulse length6 MV pulsed Van de Graaff

Main interest: Neutron induced cross sections, e.g. (n,γ), (n,f), (n,p), (n,α), and total cross section measurements.

Contact person: C. Wagemans, e-mail: Cyrillus.WAGEMANS@cec.eu.int

GELINA

FrequencyHz

Pulse Lengthns

Neutron Rates-1

Fluence Rate at 10 ms-1 cm-2

800 <1 2.5 1013 2.0 106

800 10 3.2 1013 2.5 106

100 10 4.0 1012 3.2 105

50 2000 7.3 1012 5.8 105

GELINA: TOF-facility

• Operation frequency : 40 Hz – 800 Hz• 12 Flight Paths : 8 - 400 m• Different Measurement Stations

– Total Cross Sections– Partial Cross Sections

(n,γ), (n,f), (n,p), (n,α), …FLIGHT PATHS

SOUTH

NEUTRONTARGET

ELECTRONLINAC

FLIGHT PATHSNORD

12 FP’s and different operation modes

STUDY OF (n,p) AND (n,α) REACTIONS

C. Wagemans, L. De Smet, J. Heyse, A. Steen

• 36Cl(n,p)36S, 36Cl(n,α)33P•26Al(n,p)26Mg, 26Al(n,α)23Na

Neutron energy selected via TOF at 9 m and 30 m flight paths

Recent Results :

GELINA

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gridded ionisation chamberwith CH4 gas flow

36Cl(n,α)33P

γ-ray production facilities

Photo-induced reactions

(n,γ), (p,γ), (α,γ) and the invers reactions

p process

Alpha potentials

TU Darmstadt (S-DANILAC)

Location: Darmstadt, Germany

Facility/Equipment: Superconducting DArmstadt LInear ACcelerator (S-DANILAC).The electron beam (2.5 - 120 MeV) is used to produce photons up to10 MeV via bremsstrahlung.

Main interest: Photoactivation measurements for p- and s-process

Contact person: A. Zilges e-mail: zilges@ikp.tu-darmstadt.de

• Nuclei studied so far: 96Zr, 186W, 185,187Re, 191,193Ir, 190,192,198Pt, 197Au, 196,198,204Hg, and 204Pb

• Future: 152Sm(γ,n), 100Mo(γ,n), and 148Nd(γ,n)

Photoactivation @ Eγ < 10 MeVFirst step:

activation with bremsstrahlungSecond step:

high-resolution γ-spectroscopy

TU Darmstadt

• High Resolution Photon Tagger• Energy range:

8 MeV ≤ Eγ ≤ 20 MeV• Energy resolution:

ΔE = 25 keV @ 10 MeV• Photon current:

5·104 keV-1s-1

• Direct detection of neutrons, protons, and α‘s, e.g. 86Kr(γ,n) and 205Tl(γ,n)

Direct Determination of Photodissociation Cross Sections

Location: Debrecen, Hungary

Facility/Equipment: Cyclotron: p,d,3He, 4He from 3 MeV (p) to 27 MeV (3He), Imax=50 μA

5 MeV Van de Graaff: p, d, 3He, 4He, C, N, O, Ne. Imax=1 -15 μA

1 MeV Van de Graaff: p,3He, 4He, Imax=5 μA.

Clover detector with BGO shield, precision scattering chamber.

Main interest: Study of astrophysical p-process (p and alpha capture reactions).Study of alpha-nucleus optical model potential (alpha elastic

scattering).

Contact person: E. Somorjai, e-mail: somorjai@atomki.hu

Atomki

Location: Demokritos, Greece

Facility/Equipment: 5 MeV Van de Graaff tandem for typical ion beams and

fast neutron productionScattering chamber for particle spectroscopy

Main interest: Cross section measurements mainly for nucleosynthesis modelling.Alpha and proton capture reactions relevant for the p process

Contact person: S. Harissopulos, e-mail: sharisop@mail.demokritos.gr

Demokritos

Accelerator mass spectroscopy

Isotopic ratios down to 10-16 can be measured.

This method is extremely useful for activation measurements

- where the unstable product nucleus does not emit γ-rays

- where the half-life is long

TU Munich

Location: Munich, Germany

Facility/Equipment: 14 MV tandem accelerator Gas filled magnet for AMS

Main interest: Accelerator Mass Spectroscopy (AMS) of light, medium and heavy

isotopes

Contact person: Gunther Korschinek e-mail:Gunther.Korschinek@ph.tum.de

TU Munich• Accelerator Mass Spectrometry at the Gas-filled Analyzing Magnet System

GAMS

• Examples:The Search for 60Fe in a deep-sea manganese crust gave evidence for a nearby Supernova 2.8 Myr ago at a distance of a few 10 pc.

Deep-Sea Manganese Crust

This method can also be applied for activation measurements where no γ-rays are emitted by the product nucleus (see e.g. 62Ni(n,g)63Ni).

University of Vienna

Location: Vienna, Austria

Facility/Equipment: 3-MV Pelletron tandem facility VERA (Vienna Environmental ResearchAccelerator)

Main interest: Accelerator Mass Spectroscopy (AMS) of light, medium and heavy

isotopes

Contact person: W. Kutschera e-mail: Walter.Kutschera@univie.ac.at

Preparation of radioactive samples

Location: Villingen, Switzerland

Facility/Equipment: PSI is a large scale facility but for our community the preparation of radioactive samples from the beam stop material of the PSI is very

interesting.

Main interest: Preparation of radioactive samples, e.g. 10Be, 26Al, 60Fe, 59/63Ni, 54Mn, and possibly rare earth elements like 182Hf.

Contact person: D. Schumann e-mail: dorothea.schumann@psi.ch

PSI