precise neutron inelastic cross section measurements
DESCRIPTION
Precise neutron inelastic cross section measurements. Negret 1 1 “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Bucharest, ROMANIA. Carpathian Summer School of Physics 2012, Sinaia. A. Negret - N eutron inelastic cross section measurements. Summary. Introduction - PowerPoint PPT PresentationTRANSCRIPT
Precise neutron inelastic cross section measurements
A.Negret1
1 “Horia Hulubei” National Institute for Physics and Nuclear Engineering,Bucharest, ROMANIA
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Summary
Introduction
Experimental setup & Analysis
Results for 28Si(n,n’)28Si
Comparison with 25Mg(,n)28Si
Conclusion
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
IntroductionIntroduction
Experimental setup & Analysis
Results for 28Si(n,n’)28Si
Comparison with 25Mg(,n)28Si
Conclusion
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Neutron data
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, 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 PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
(N,Z)
n
What do we measure
v
n(N,Z)
Elastic scattering
Inelastic scattering
Nuclear reactions
Fission
(N2,Z2)
(N1,Z1) n
n
Cross section ()
n
(N,Z)
(N+1,Z-1)
p
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Neutron inelastic scattering
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Experimental setup & AnalysisIntroduction
Experimental setup & Analysis
Results for 28Si(n,n’)28Si
Comparison with 25Mg(,n)28Si
Conclusion
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Overview of the experimental procedure
Neutron source
200 m flight path
FP3/200 cabin; GAINS + FC
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, 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 PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
GAINS
8 HPGe detectors @ 110° & 150° (Accurate integration of angular distribution up to the sixth order of Legendre polynomials)
• TOF technique:Amplitude gamma energyTime neutron energy
• Digitizer-based acquisition (Acqiris DC440, 420 MS/s, 12 bits)
• Beam monitoring: 235U Fission chamber
Gamma Array for Inelasic Neutron Scattering
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Experimental problems
The gamma flash
Time resolution
Long time measurements
Distance from the neutron source : FP = 200m
Small neutron flux
Stability of the electronics
Simplification of the acquisition system
The digitizer-based acquisition
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, 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 sectionLevel cross sections
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
ResultsIntroduction
Experimental setup & Analysis
Results for 28Si(n,n’)28Si
Comparison with 25Mg(,n)28Si
Conclusion
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
What did we see?
28Si + n28Si+n
29Si
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Gamma production cross sections in 28Si
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Total inelastic cross section
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Level production cross sections
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Comparison with 25Mg(,n)28SiIntroduction
Experimental setup & Analysis
Results for 28Si(n,n’)28Si
Comparison with 25Mg(,n)28Si
Conclusion
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
28Si + n 28Si+n29Si
28Si(n,n’)28Si vs 25Mg(,n)28Si
25Mg + 25Mg(,n)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 PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
28Si(n,n’)28Si vs 25Mg(,n)28Si
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
28Si(n,n’)28Si vs 25Mg(,n)28Si
ConclusionsIntroduction
Experimental setup & Analysis
Results for 28Si(n,n’)28Si
Comparison with 25Mg(,n)28Si
Conclusion
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
Conclusions
• The GAINS spectrometer installed at the neutron source GELINArepresents 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 PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
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Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements
The ERINDA consortium groups 13 partners, 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
Thank you!
Carpathian Summer School of PhysicsCarpathian Summer School of Physics 2012, Sinaia2012, Sinaia
A. Negret - Neutron inelastic cross section measurements