1. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Neutrons For Science (NFS) at SPIRAL-2 ● The spiral 2 project ● Neutron production modes ● Design ● Beam characteristics ● Irradiation facility ● Physics case X. Ledoux and the NFS collaboration

2. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr SPIRAL-2 40MeV; 5mA deuteronsneutrons graphite UCx

3. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr M. Jacquemet, GANIL Colloquium, Giens, june 2006 Spiral-2 Layout

4. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Beams delivered by the LINAG LINear Accelerator of Ganil Power at full intensity I=5mA, E=40 MeV P=200 kW Challenge: radioprotection 10 15 n.s Converter composition ● Two sources one for deuterons one for heavy ions ● Two RFQs q/A=3 q/A=6 for heavy ions (by now optional) ● LINAG F 0 = 88 MHz T=11 ns 26 cavities Burst width = 200 ps ● Main specifications : 5 mA of 40 MeV deuterons 1 mA for heavy ions at E max =14,5 A.MeV All details available on www.ganil.fr

5. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Neutron For Science A working group was created to study : The possible use of the LINAG beam to built a neutron facility The Physics case realizable at NFS The facility will be composed of two parts : Neutron beam Irradiation station Means : Deuteron and proton beams Thin and thick converter Dedicated room(s) A letter of intents was presented to the Scientific Advisory Committee of SPIRAL 2

6. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Neutron spectra provided at NFS (1) Deuteron break-up on Thick converter E deut = 40 MeV The deuteron are stopped in the converter (1cm) Continuous beam = 14 MeV Be instead C converter allows to increase the flux by a factor of 2 Meulders et al., Phys. Med. Biol. (1975)vol 20 n°2, p235 ⇒ Similar to IFMIF spectrum

7. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Neutron spectra provided at NFS (2) Neutron production by 7 Li(p,n) 7 Be reaction Thin converter (1-3 mm) Quasi-monokinetic beam E p = 3 – 33 MeV E n ≈ E p –1,6 MeV Schumacher et al.,NIMA421 (1999) p2843 7 Li(p,n) 7 Be

8. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Neutron For Science Facility Sample Detector(s) Converter cave - Beam line extension - Clearing magnet - Beam dump - Irradiation stations (n, p, d) Experimental Hall - Beam(s) at 0° and 30° optional - Collimator design ↔ beam quality - Size (L ⅹ l) ≃ (30m ⅹ 6m) time-of-flight measurement measurement at desired distance large experimental set-up

9. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Beam repetition rate Requirement: differentiation of 2 neutrons with the ToF t and t+T L(m)E th (MeV) T(  s) N I max (  A) 50.1110050 300.166008 T ≃ 1  s T ≃ 6  sT ≃ 1  s T ≃ 6  s T LINAG = 11 ns Take only one burst over N (f = F 0 /N) - burst selector - I = I max / N, with I max =5mA

10. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Energy resolution L=30m and fast detector ⇒ high resolution measurement HPGe detector ⇒  E/E < 5% for L=30 m The neutron energy is measured by time-of-flight technique Good resolution measurements require : - A unique burst selector - Burst duration on converter < 1ns (buncher might be needed)  t : Full time resolution :  t d ≃ 1 ns scintillator  ≃ 8 ns HPGe  t b ≃ 1 ns

11. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr N-tof : CERN, Spallation,L=185 m,F=0.4Hz GELINA : Geel, Photofission, F=800Hz,30 m Spiral-2 : high intensity high resolution Comparison with other neutron beam facilities Complementary to the existing facilities E n : from 1 MeV to 40 MeV High flux ⇒ small samples coincident experiments Reduced  flash

12. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Comparison with other neutron beam facilities ● Disadvantages of NFS - high frequency - flux by burst smaller than n-tof or Gelina - only fast neutrons (1-40 MeV) ●Advantages of NFS : high average flux in the 1-40 MeV range : - small samples - coincident experiments production mode : - no high energy neutron (in comparison with spallation) - reduced gamma flash (in comparison with photoreaction) Hall size : - desired distance between 5 and 30 m high flux or high resolution - use of large set-up

13. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Measurement by activation technique - Neutron induced reaction The sample is put very close of the converter White source = 14 MeV  >5.10 11 n/s/cm 2 for I d =50  A Quasi-monoenergetic (Li converter on carbon back-up) - Proton and Deuteron induced reaction Two irradiation stations can be installed in the converter cave : - Off-line activity measurement in a separate room - Detectors for flux monitoring → Cross-section measurement : I max limited to 50  A - Low power deposition on converter < 2 kW - Reduced activation  « easy » sample manipulation

14. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Monoenergetic neutrons beam d + d → n + 3 He Q = 3.27 MeV - En(0 deg) = 3.2 –7.2 MeV for Ed= 0 - 4 MeV - Gaseous or solid (TiD) targets d + T → n + 4 He Q = 17.59 MeV - En(0 deg) = 14 –20 MeV for Ed= 0 - 3.7 MeV - only solid target (TiT) Mono-energetic neutrons can be produced by the following reactions Low energy deuteron beam (Ed < 4 MeV) The neutron flux depend on the power the target can sustain

15. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Converter cave roof 1,5 m walls 2 m TOF room : wall thickness ≈ 50cm neutron beam dump at 0 degree Light concrete: less activation than in concrete loaded with iron Radioprotection simulations

16. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Radioprotection Neutron dose calculation for 100  A d + Be (1 cm) Code PHITS (V. Blideanu) Public area : D < 0,5  Sv/h

17. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr

18. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Possible implementation

19. NIPNE, April 4, 2007 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 (ADS) - Validation of codes - Nuclear medicine - Development and characterization of new detectors - Irradiation of chips and electronics structures used in space Workshop and reports: International Workshop on Neutrons for Science (NFS) at SPIRAL-2, GANIL, Caen, France; 13-14 December 2004. D. Ridikas et al, “Neutrons for Science (NfS) at SPIRAL-2”, Internal report DAPNIA report 05-30, Saclay, France (2005), A. Plompen, “Nuclear Data Needs for Nuclear Energy (fission) and Possible Contributions of SPIRAL2”, 15 th Colloque GANIL, Giens, France (2006) U. Fischer, “Nuclear data needs for fusion technology and possible contribution by SPIRAL2”, 15 th Colloque GANIL, Giens, France (2006).

20. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Neutron induced fission 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 Study of the fission process Continuous spectrum → continuous excitation energy Coincidence experiment (A,Z) fragment distribution

21. NIPNE, April 4, 2007 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)

22. NIPNE, April 4, 2007 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 I max limited to 50  A - Power deposition on converter < 2 kW - Reduced activation  « easy » sample manipulation

23. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr Summary - White and quasi-monokinetic spectra in the 1-40 MeV range - Neutron beams with high flux and good energy resolution - Complementary to the existing n-tof facilities - Irradiation stations for activation measurements (n, p, d) - Intensity on the converter limited to 50  A reduced activation light converter design - NFS is somewhat independent of RIB production - Could start as soon as the LINAG is ready (2011) The LINAG characteristics are particularly well adapted to a neutron facility at SPIRAL-2

24. NIPNE, April 4, 2007 Contact: xavier.ledoux@cea.fr The NFS collaboration X. Ledoux 1), M. Aïche 2), G. Ban 3), G. Barreau 2), P. Baumann 4), P. Bem 5), V. Blideanu 6), J. Blomgren 7), S. Czajkowski 2), P. Dessagne 4), E. Dupont 6), T. Ethvignot 1), U. Fischer 8), F. Gunsing 6), B. Jacquot 9), B. Jurado 2), M. Kerveno 4), F. R. Lecolley 3), J. L. Lecouey 4), F. Negoita 10), S. Oberstedt 11), M. Petrascu 10), A.J.M. Plompen 11), F. Rejmund 9), D. Ridikas 6), G. Rudolf 4), O. Shcherbakov 12), S.P. Simakov 8), J. Taïeb 1) 1) Service de Physique Nucléaire, CEA/DIF, BP 12, 91980 Bruyères-le-Châtel Cedex, France 2) Centre d’Etudes Nucléaires de Bordeaux-Gradignan, 33175 Gradignan, France 3) Laboratoire de Physique Corpusculaire, ISMRa et Université de Caen, CNRS/IN2P3,France 4) Institut Pluridisciplinaire Henri Curien, Strasbourg, France 5) Nuclear Physics Institute, 25068 Řež, Czech Republic 6) Centre d’Etudes Nucléaires de Saclay, DSM/DAPNIA, France 7) Department of Neutron Research, Uppsala University, Uppsala, Sweden 8) Forschungszentrum Karlsruhe, Institute for Reactor Safety, Karlsruhe, Germany 9) GANIL, CEA/CNRS, Caen, France 10) NIPNE, Bucharest, Romania 11) Institute for Reference Materials and Measurements, Geel, Belgium 12) PNPI, Gatchina, Russia