Precise neutron inelastic cross section measurements • Negret1 • 1“Horia Hulubei” National Institute for Physics and Nuclear Engineering, • Bucharest, ROMANIA Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Summary Introduction Experimental setup & Analysis Results for 28Si(n,n’g)28Si Comparison with 25Mg(a,ng)28Si Conclusion Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Introduction Introduction Experimental setup & Analysis Results for 28Si(n,n’g)28Si Comparison with 25Mg(a,ng)28Si Conclusion Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Neutron data Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements NEA High priority list • 28Si – Gas Cooled Fast Reactors (GFT) • 56Fe, 206,207,208Pb – structural materials Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements n (N,Z) n g (N,Z) n p (N,Z) (N+1,Z-1) v n (N1,Z1) n (N2,Z2) What do we measure Elastic scattering Inelastic scattering Nuclear reactions Cross section (s) Fission Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Neutron inelastic scattering Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Experimental setup & Analysis Introduction Experimental setup & Analysis Results for 28Si(n,n’g)28Si Comparison with 25Mg(a,ng)28Si Conclusion Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Overview of the experimental procedure FP3/200 cabin; GAINS + FC 200 m flight path Neutron source Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements GELINA neutron source • Electron linac (150 MeV) + 238U target • Pulse width ~1 ns • Repetition rate: 800 Hz • Energy range: 0 – 20 MeV • Gamma flash from • bremsstrahlung • Flight path: 200m • (~550 neutrons/cm2s) Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements GAINS Gamma Array for Inelasic Neutron Scattering • 8 HPGe detectors @ 110° & 150° (Accurate integration of angular distribution up to the sixth order of Legendre polynomials) • TOF technique: • Amplitude gamma energy • Time neutron energy • Digitizer-based acquisition • (Acqiris DC440, 420 MS/s, 12 bits) • Beam monitoring: 235U Fission • chamber Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Experimental problems The digitizer-based acquisition The gamma flash Time resolution Distance from the neutron source : FP = 200m Small neutron flux Long time measurements Stability of the electronics Simplification of the acquisition system Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Overview of the data analysis 8 x HPGE yield FC yield Efficiency: Monte-Carlo simulation Multiple scattering correction: Monte-Carlo simulation Gamma Production cross sections NDS: level scheme Total inelastic cross section Level cross sections Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Results Introduction Experimental setup & Analysis Results for 28Si(n,n’g)28Si Comparison with 25Mg(a,ng)28Si Conclusion Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements What did we see? 28Si + n 29Si 28Si+n Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Gamma production cross sections in 28Si Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Total inelastic cross section Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Level production cross sections Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Comparison with 25Mg(a,ng)28Si Introduction Experimental setup & Analysis Results for 28Si(n,n’g)28Si Comparison with 25Mg(a,ng)28Si Conclusion Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements 28Si(n,n’g)28Si vs 25Mg(a,ng)28Si 28Si + n 29Si 28Si+n 25Mg + a • 25Mg(a,ng)28Si measurement performed at the Tandem accelerator of IFIN-HH, Bucharest: • The same Compound nucleus, 29Si • The same exit channel • We measured the production cross sections for the same gamma rays: Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements 28Si(n,n’g)28Si vs 25Mg(a,ng)28Si Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements 28Si(n,n’g)28Si vs 25Mg(a,ng)28Si Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Conclusions Introduction Experimental setup & Analysis Results for 28Si(n,n’g)28Si Comparison with 25Mg(a,ng)28Si Conclusion Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Conclusions • The GAINS spectrometer installed at the neutron source GELINA • represents a powerful tool for producing neutron inelastic • cross sections • On-going experiments and analysis for many data sets: • 206Pb, natFe, 28Si, 24Mg, 23Na, 12C, 90Zr, 57Fe, natCu. • Current attempts aim to the development of alternative methods • to the direct measurement of neutron-induced cross sections. Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Advertisement The ERINDA consortium groups 13partners, equipped with nuclear data research infrastructures. The project sponsors the transnational access for experiments performed at any of the 13 facilities. The TANDEM accelerator of IFIN-HH is part of ERINDA. The next (and last) deadline for proposals: September 30, 2012 www.erinda.org Carpathian Summer School of Physics2012, Sinaia
A. Negret - Neutron inelastic cross section measurements Thank you! Carpathian Summer School of Physics2012, Sinaia
