Am cross section measurements at GELINA. S. Kopecky EC JRC IRMM Standards for Nuclear Safety, Security and Safeguards (SN3S)

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1 241 Am cross section measurements at GELINA S. Kopecky EC JRC IRMM Standards for Nuclear Safety, Security and Safeguards (SN3S)

2 TOF - Facility GELINA Pulsed white neutron source (10 mev < E n < 20 MeV) FLIGHT PATHS NORD Neutron energy : time-of-flight (TOF) ELECTRON LINAC Multi-user facility: 10 flight paths (10 m m) TARGET HALL Measurement stations with special equipment to perform: Total cross section measurements Partial cross section measurements FLIGHT PATHS SOUTH Mondelaers and Schillebeeckx, Notizario 11 (2006) 19

3 241 Am + n : TOF experiments at GELINA Sample Production (JRC ITU ) AmO 2 homogeneously diluted in a Y 2 O 3 matrix (solgel method) Characterization (JRC IRMM & ITU) Total amount : calorimetry (main uncertainty component : mw/g) mg Area : optical surface inspection of X-ray radiograph with microscope cm 2 n = atom/barn Experiments Transmission at 25 m ( 6 Li-glass scintilllators) Capture at 12.5 m Total energy detection using C 6 D 6 Flux : 10 B(n,) using IC Normalization : internal using transmission data see also Fraval, ND2013, PA2 measurements at n_tof

4 Transmission measurements at 25 m Moderated spectrum T exp C C in out B B in out e n tot E r = ev of 238 U+n (E r, g n, ) L = m

5 Counts / (1/ns) Transmission data Transmission Counts / (1/ns) 10 2 C ' out 10 2 C ' in B ' out B ' in Na Bi T exp C C ' ' in out ' B B in ' out Na Bi 10-1 Co W Ag 10-1 Co W Ag Time Of Flight / ns Time Of Flight / ns Fixed background filters : Na, Bi, Co Time Of Flight / ns

6 Transmission Residuals Transmission data Resonance analysis with REFIT Transmission Residuals Gas model Crystal lattice K K Exp. REFIT (free gas) Exp. REFIT (DOPUSH) Neutron energy / ev Neutron energy / ev At the moment: E r, ng n, ~

7 Comparison with LANSCE (Jandel et al.) E r and E r / ev / mev GELINA LANSCE GELINA LANSCE Weston and Todd GELINA (# 1786) : - Flight path length traceable to E r = ev ev of 238 U + n (ORELA) - Response function of GELINA in REFIT includes neutron storage term (Ikeda and Carpenter), (see # 1786)

8 Capture measurements at 12.5 m Total energy detection principle C6D6 liquid scintillators 125 o PHWT Flux measurements (IC) R(E 10 B(n,) < 150 kev d,e ) WF(E d ) de d ke WF : from MC simulations C w (T n ) C c (T n,e d ) WF(E d ) de d Borella et al., NIMA 577(2007) 626

9 Efficiency Effective detection efficiency 0.06 Monte Carlo simulations Gamma-ray energy / MeV

10 Yield Counts / (1/ns) Weighted counts / (1/ns) Capture data (counts) for E d > 650 kev C (t) C (t) B (t) 10 5 C w B w 10 4 No sample Al + Y 2 O 3 Time ind B ov (t) B o B (t) Y exp N ' w C B ' C B ' w ' Y B n (t) Time-of-flight / ns Time-of-flight / ns Fixed background filters 0.8 Time dependent background dominates Time-of-flight / ns

11 Pulse height spectra : threshold Counts / (1/keV) Am(n,) resonances 241 Am decay 10-2 C C(E) de E d Deposited energy / kev Standard E d 160 kev E 300 kev 241 Am 650 kev 850 kev

12 Capture yield: impact of threshold E d > 160 and 650 kev Weighted counts 10 4 Ed > 650 kev Ed > 160 kev E d > 650 kev E d > 160 kev Neutron energy / ev

13 Transmission Yield Transmission + capture at GELINA 0.8 Experiment REFIT (normalization) Experiment REFIT (res. par.) Neutron energy / ev N c = Energy / ev n / mev / mev (0.0004) (0.39) (0.0009) (0.63) (0.0035) (0.79)

14 241 Am(n,) : experimental yield + fit (Yield E 1/2 ) / ev 1/ Y exp Y fit (+ bound state) Y fit (E R > 0) Y fit (+ 1/v) Neutron energy / ev (n th,) = b g f = 1.00 (n th,) = 749 g f = 1.04 Mughabghab g f = 1.05

15 (n th, ) : GELINA experimental data 900 GELINA Pile oscillator NAA : g+m NAA : g / ENDF/B - VI.8 JEFF JENDL g+m (n th,) / barn TOF g f = Year

16 (n th, ) : GELINA experimental data 900 GELINA Pile oscillator NAA : g+m NAA : g / ENDF/B - VI.8 JEFF JENDL g+m (n th,) / barn TOF g f = Year

17 RI / barn RI : GELINA evaluated data 6000 This work (+ bound state) Nakamuara et al. Harbour et al. ENDF/B-VI.8 Bak et al JEFF Gavrilov et al. Shinohara et al. JENDL Maidana et al RI (E) de E E c Cut - off energy, E c / ev