1. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Neutrons For Science (NFS) at SPIRAL-2 X. Ledoux and the NFS collaboration -Description -Physics case

2. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr One of the Linag Experimental Area facilities Pulsed neutron beam –Energy range: 1-40MeV –High intensity –Very well collimated beam Irradiation station –Neutron induced reaction (high flux) –Proton and Deuteron induced reactions Use of the Ion beam of the LINAG (SPIRAL-2 driver) –Deuteron and proton beam –5 mA at full power –Pulsed beam 88 MHz The Neutrons For Science project

3. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr The ion beams delivered by the LINAG are adapted for the neutron production: Neutrons For Science Facility NFS is composed of : ● Pulsed neutron beam with a 20m long hall → TOF measurements ● Irradiation facility in n, p and d induced reactions → activation experiments ⇒ Similar to IFMIF spectrum Thick converters (1cm) E max = 40 MeV = 14 MeV Continuous spectra Thin converter (1-3 mm) E p = 3 – 33 MeV E n ≈ E p –2 MeV Quasi monokinectic spectra 7 Li(p,n) 7 Be

4. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr 30 MeV p + 0.5 cm Ta 30 MeV p + 2.0 cm 7 Li Fast Reactor 40 MeV d + 1.0 cm Be Low energy spectra optimisation The (30MeV) p+Ta reaction produces more neutrons in the 100keV – 3MeV domain Than the (40MeV) d+Be reaction ⇨ Interest for next generations of reactors Neutrons yield at θ<5°

5. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Schematic view of NFS TOF hall Area for Actinide Samples Neutron beam Neutron Beam dump TOF Hall - beam line at 0° - size (L ⅹ l) ≃ (20m ⅹ 6m) time-of-flight measurement experimental set-up position Converter room - clearing magnet - beam dump - Irradiation station neutron, proton and deuteron activation measurement

6. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Beam characteristic ● Energy resolution → Energy resolution at 20m Fast detector ΔE/E < 1% HPGe detector ΔE/E < 4% ● Neutron beam frequency - TOF measurements without neutron overlap requires 1 MHz < F <1 kHz - Fast beam chopper needed ⇨ Imax = 50µA → P < 2 kW ● Measurement by activation technique : - I max = 50 µA for safety reasons - Neutron induced reactions ( = 14 MeV Φ>5.10 11 n/s/cm 2 ) - Proton and Deuteron induced reactions (2 MeV < E < 40 MeV)

7. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Spallation source: WNR : Los Alamos N-tof : CERN Photofission source: GELINA : Geel E n : from 1 MeV to 40 MeV High flux ⇒ small samples coincident experiments Reduced  flash Complementary to the existing facilities Neutron beam flux

8. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr General Physics Case Reactions induced by fast neutrons are of first importance in the following topics : ● Fission reactors of new generation ● Fusion technology ● Studies related to hybrid reactors ● Validation of codes and evaluated data bases ● Nuclear medicine ● Development and characterization of neutrons detectors ● Electronics (SEU)

9. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Neutron induced fission Study of the fission process Continuous spectrum → continuous excitation energy (A,Z) fragment distribution Need of data for fast neutron essentially for minor actinides ADS, GEN IV reactors Cross-section measurements Neutron, gamma multiplicity and spectra Fragment yields NFS short flight path → High flux Small samples (  emitters) Coincidence measurements Complementary to surrogate reactions Limited to 10 MeV Model dependence

10. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr (n,X) cross section measurements (n,xn) reactions Maximum  in the NFS energy range Neutron multiplication (n,LCP) Gazes and default production Energy deposition in therapy Composite particle prediction → no model works In-beam  -ray spectroscopy White source and quasi-monokinetic spectrum (n,2n), (n,np), (n,  ) reactions Use of large Ge array for  -  coincidence measurements Double differential measurements (n,xn), (n,LCP) Few data exist between 20 and 50 MeV Use of existing detection set-ups 56 Fe(n,  ) cross sections in several data bases. Incident energy (MeV)  (barns)

11. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Cross-section measurement needed for fusion technology IFMIF and ITER need neutron and deuteron induced reactions cross-section. - Data scarce or not existing - Large discrepancies between data bases Material to be studied for IFMIF : Al, Fe, Cr, Cu, Nb for cavities and beam transport elements Be, C, O, N, Na, K, S, Ca, Fe, Cr, Ni for Li loop Cross-section measurement by activation technique 2 irradiation stations : - Neutron induced reactions - Proton and deuteron

12. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Key experiments at NFS ● Measurement of (n,n’ γ ) and (n,xn’ γ ) cross-sections (IPHC Strasbourg) - set-up existing and already used at GEEL and Louvain-la-Neuve - reliable neutron dosimetry needed - flight path of at least 20 m ● Study of the pre-equilibrium in the (n,xn) reactions (CEA/DIF Bruyères-le-Châtel) - set-up existing and already used at the Tandem of Bruyères-le-Châtel - very well collimated neutron beam ● Measurement of fission-fragment yields from neutron-induced fission on Minor Actinides ( 237 Np, 241,243 Am) in the 1-20 MeV range (CENBG Bordeaux – Manchester University) - set-up under development - very well collimated neutron beam - thin layer of actinide ● Cross-section measurement of neutron and deuteron induced reactions by activation technique (FZK Karlsruhe and NPI Prague) - irradiation station - off-line gamma ray spectroscopy

13. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr Summary - Neutron beams with high flux and good energy resolution - White and quasi-monokinetic spectra in the 1-40 MeV range - Complementary to the existing n-tof facilities - Irradiation stations for activation measurements (n, p, d) - NFS will open GANIL to new physicists - NFS is somewhat independent of RIB production - Could start as soon as the LINAG is ready (2011) - NFS Collaboration (New collaborators and new physics case are welcome) - The building design is under study NFS will be a very powerful tool for applied and fundamental research

14. LEA workshop, Catane, October 13-15, 2008 Contact: xavier.ledoux@cea.fr X. Ledoux, E. Bauge, G. Belier, T. Ethvignot, J. Taïeb, C. Varignon, CEA/DIF/DPTA/SPN, Bruyères-le-Châtel, France S. Andriamonje, E. Dupont, D. Doré, F. Gunsing, D. Ridikas, CEA/DSM/IRFU/SPhN, Saclay, France V. Blideanu, CEA/DSM/IRFU/Senac, Saclay, France M. Aïche, G. Barreau, S. Czajkowski, B. Jurado, CENBG, Gradignan, France G. Ban, F. R. Lecolley, J. F. Lecolley, J. L. Lecouey, N. Marie, J. C. Steckmeyer, LPC, Caen, France P. Baumann, P. Dessagne, M. Kerveno, G. Rudolf, IPHC, Strasbourg, France P. Bem, NPI, Řež, Czech Republic J. Blomgren, DNR, Uppsala, Sweden U. Fischer, S. P. Simakov, FZK, Karlsruhe, Germany B. Jacquot, F. Rejmund, GANIL, Caen, France L. Perrot, IPNO, Orsay, France M. Avrigeanu, V. Avrigeanu, C. Borcea, F. Negoita, M. Petrascu, NIPNE, Bucharest, Romania S. Oberstedt, A.J.M. Plompen, JRC/IRMM, Geel, Belgium O. Shcherbakov, PNPI, Gatchina, Russia M. Fallot, L. Giot, Subatech, Nantes, France A. G. Smith, I. Tsekhanovich, Department of Physics and Astronomy, University of Manchester, Manchester, UK O. Serot, J.C. Sublet, CEA/DEN, Cadarache, France T. Caillaud, O. Landoas, I. Thfoin, B. Rossé, CEA/DIF/DCRE/ SCEP, Bruyères-le-Châtel, France The NFS collaboration