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Neutrons For Science (NFS) at SPIRAL-2 X. Ledoux and the NFS collaboration. Description Physics case. 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)
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Neutrons For Science (NFS) at SPIRAL-2 X. Ledoux and the NFS collaboration • Description • Physics case 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 Contact: xavier.ledoux@cea.fr
Thin converter (1-3 mm) Ep = 3 – 33 MeV En≈ Ep –2 MeV Quasi monokinectic spectra Thick converters (1cm) Emax = 40 MeV <E> = 14 MeV Continuous spectra 7Li(p,n)7Be 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 The ion beams delivered by the LINAG are adapted for the neutron production: ⇒ Similar to IFMIF spectrum Contact: xavier.ledoux@cea.fr
30 MeV p + 2.0 cm 7Li 30 MeV p + 0.5 cm Ta Fast Reactor 40 MeV d + 1.0 cm Be Low energy spectra optimisation Neutrons yield at θ<5° 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 Contact: xavier.ledoux@cea.fr
Schematic view of NFS Converter room - clearing magnet - beam dump - Irradiation station neutron, proton and deuteron activation measurement Neutron Beam dump TOF hall Neutron beam Area for Actinide Samples TOF Hall - beam line at 0° - size (Lⅹl)≃(20m ⅹ 6m) time-of-flight measurement experimental set-up position Contact: xavier.ledoux@cea.fr
Beam characteristic • ● Neutron beam frequency • - TOF measurements without neutron overlap requires 1 MHz < F <1 kHz • Fast beam chopper needed⇨ Imax = 50µA → P < 2 kW • ● Energy resolution • → Energy resolution at 20m • Fast detector ΔE/E < 1% • HPGe detector ΔE/E < 4% ● Measurement by activation technique : - Imax = 50 µA for safety reasons - Neutron induced reactions (<E> = 14 MeV Φ>5.1011n/s/cm2) - Proton and Deuteron induced reactions (2 MeV < E < 40 MeV) Contact: xavier.ledoux@cea.fr
Neutron beam flux Spallation source: WNR :Los Alamos N-tof: CERN Photofission source: GELINA : Geel • En: from 1 MeV to 40 MeV • High flux ⇒small samples • coincident experiments • Reduced g flash Complementary to the existing facilities 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) 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 (a emitters) Coincidence measurements • Complementary to surrogate reactions Limited to 10 MeV Model dependence Contact: xavier.ledoux@cea.fr
56Fe(n,a) cross sections in several data bases. s (barns) Incident energy (MeV) (n,X) cross section measurements • (n,xn) reactions Maximum s 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 g-ray spectroscopy White source and quasi-monokinetic spectrum (n,2n), (n,np), (n,a) reactions Use of large Ge array for g-g coincidence measurements • Double differential measurements (n,xn), (n,LCP) Few data exist between 20 and 50 MeV Use of existing detection set-ups Contact: xavier.ledoux@cea.fr
Cross-section measurement needed for fusion technology •Cross-section measurement by activation technique •2 irradiation stations : - Neutron induced reactions - Proton and deuteron 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 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 (237Np, 241,243Am) 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 Contact: xavier.ledoux@cea.fr
Summary NFS will be a very powerful tool for applied and fundamental research • - 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 Contact: xavier.ledoux@cea.fr
The NFS collaboration 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 Contact: xavier.ledoux@cea.fr