Nuclear Data Activities at Nuclear Data Activities at PTB PTB R. Nolte Physikalisch-Technische Bundesanstalt Braunschweig Fachbereich 6.4
Nuclear Data Activities at PTBNuclear Data Activities at PTB
R. Nolte
Physikalisch-Technische Bundesanstalt Braunschweig
Fachbereich 6.4
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PTB Accelerator FacilityPTB Accelerator Facility
•3.5 MV van-de-Graaf: p, d, beams
•CV28 isochronous cyclotron:
p (< 19 MeV), d (< 13.5 MeV), (< 28 MeV)
•ns pulsing systems at both accelerator (t = 1.5 ns - 3 ns)
•monenerg. neutron beams:
T(d,n), T(p,n), 7Li(p,n)
•white neutron beams:
9Be(p,n), 9Be(d,n)
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Reference InstrumentsReference Instruments
All measurements relative to differential n-p scattering cross section (ENDF/B-V)
Reference instruments
Recoil Proton Telescopes: 1.2 MeV ≤ En ≤ 200 MeV
Recoil Proton Prop. Counter: En 1.2 MeV
absolute methods (TCAP) presently not available
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TOF spectrometerTOF spectrometer
•PE / Fe collimator fan
•flight path: 12 m (35 m)
•optimized for 5 MeV - 15 MeV
•Neutron sources:–D(d,n)
–15N(p,n) (under dev.)
–9Be(p,n), 9Be(d,n)
–....
•available for: –target and detector
development
–nuclear data work
NE213-Detectors:• M: 1.5”1.5”• D1: 4” 2 ”• D2-5: 10” 2”
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Scattering Cross SectionScattering Cross Section
•TOF spectrometer: E/E 2%
•neutron source: D(d,n) (D2 gas target)(monoenerg. + breakup neutrons)
•present energy range: 5 MeV - 15 MeV
•measurement capabilities:– elastic and inelastic scattering (DX)– neutron emission spectra (DDX)
•present focus: fusion neutronics
•future work:– upgrades and extension to lower
energies (> 2 MeV)– know-how transfer– …
sample incident energyregion (in MeV) points
16O 6.42 - 14.89 1112C 13.33 - 15.82 4
natFe 9.41 - 15.20 12natPb 7.93 - 14.23 7natCr 7.95 - 14.76 1051V 7.99 - 14.37 11natTi 7.93 - 14.72 11natSi 7.89 - 13.85 1014N 7.89 - 13.85 7
natCu 6.95 - 14.18 8natW 7.19 - 14.10 8natNb ( 7 - 14 )
D. Schmidt D. Schmidt et al.et al.
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28,29,3028,29,30Si(n,n) and Si(n,n) and 28,29,3028,29,30Si(n,n')Si(n,n')
•Normalization by n-p scattering measurements
•Full Monte Carlo simulation
•Iterative adjustment of cross sections by comparison of calc. and exp. TOF spectra
without breakup correction
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Example: Si cross sectionsExample: Si cross sections
D. Schmidt et al.: NDST 2001, Tsukuba
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Activation Cross SectionsActivation Cross Sections
•Reference reaction: 238U(n,f)
•Neutron source: D(d,n)
•Correction for activation by breakup neutrons
•Energy region: 7 MeV - 15 MeV
W. Mannhart W. Mannhart et al.et al.
24Mg(n,p)24Na
27Al(n,p)27Mg, 27Al(n,)24Na
28Si(n,p)28Al, 20Si(n,a)27Mg
46Ti(n,p)46Sc, natTi(n,x)48Sc
51V(n,p)51Ti, 51V(n,)38Sc
52 Cr(n,p)52V, 52Cr(n,p)52V, 52Cr(n,2n)51Cr
54Fe(n,p)54Mn, 54Fe(n,)51Cr, 56Fe(n,p)56Mn
59Co(n,p)59Fe, 59Co(n,)56Mn, 59Co(n,2n)58m+gCo
59Ni(n,p)58Co, 59Ni(n,np)57Co, 58Ni(n,2n)57Ni
63Cu(n,2n)62Cu, 65Cu(n,p)65Ni
64Zn(n,p)64Cu, 64Zn(n,2n)63Zn
93Nb(n,2n)92mNb, 103Rh(n,n')103mRh
Measured cross section (as of 2004)
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Example: Si activation cross sectionsExample: Si activation cross sections
W. Mannhart et al.: NDST 2001, Tsukuba
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Nuclear data at intermediate energiesNuclear data at intermediate energies
R. Nolte et al.
Neutron beam facilities at:
• Louvain-la-Neuve (UCL) (33 MeV – 60 MeV)
• Cape Town (TLABS) (60 MeV – 200 MeV)
Quasi-monoenergetic beams: 7Li(p,n)
Recent projects:
• Fission cross sections: 235,238U, 209Bi, natPb
• Production of res. nuclei: together with ZSR Hannover
• 232Th(n,5n) by -detection: together with IReS Strasbourg
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UCL Neutron beam facilityUCL Neutron beam facility
Neutron production: 7Li(p,n) 3 mm, 5 mm natLi targets
Proton energy: 25 MeV - 65 MeV
Proton current: 10 nA - 10A
External beam pulser: pulse separation 500 ns
Three reference neutron beams: Epeak 33 MeV, 45 MeV, 60 MeV
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TLABS neutron beam facilityTLABS neutron beam facility
Neutron production:7Li(p,n), 5 mm target
Proton energy:up to 200 MeV
Proton current: max. 3 A on Li target
External beam pulser: pulse separation 360 ns
Collimator fan:0°, 4°, 8°, 12°, 16°
Characterized neutron beams:Epeak 66, 100, 150, 200 MeV
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Neutron reference beams (UCL and TLABS)Neutron reference beams (UCL and TLABS)
Uncertainty of peak fluence: 0/0 = 0.025 - 0.03 (UCL)(w/o n-p cross section) = 0.04 - 0.05 (TLABS)
Relative peak fluence: 0 / = 0.3 - 0.4
High-energy peaks broadened by time resolution of detectors
0 20 40 60 80 100 120 140 160 180 200 2200.00
0.05
0.10
0.15
0.20
0.25
( E
/
) /
Me
V-1
E / MeV
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232232Th(n,5nTh(n,5n))228228Th-ExperimentTh-Experiment
Experiment UCL 07/04: 7Li(p,n)-Beam:
Ep = 32, 36.5, 38, 40, 44, 48.5 MeV
fluence: RPT, 238U-FCspectral fluence: E TOF, unfolding
beam profile: (r)/ TLD, image plate-spectra+TOF: N(E) HPGe
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Fission cross sectionsFission cross sections
•Fission cross sections measured with PPFC‘s
•Fluence measurement with two RPT‘s (rel. to diff. n-p scattering cross section)
20 40 60 80 100 120 140 160 180 200
1.2
1.4
1.6
1.8
exp. PTB exp. PTB exp. KRI/UU INDC (LANL) MCNPX def. MCNPX w/o MPM BRC
f / b
E / MeV
238U
0 20 40 60 80 100 120 140 160 180 200 22010-1
100
101
102
exp. PTB exp. KRI/UU INDC MCNPX def. MCNPX w/o MPM
f / m
b
E / MeV
209Bi
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Future prospects at PTBFuture prospects at PTB
• Running projects:
Pb(n,n‘) with 15N(p,n) source (En = 2 - 4 MeV)(PhD thesis E. Pönitz)
• Wolf Mannhart and Dankwart Schmidt will retire in Nov. 06:
• Scattering cross sections: Knowhow transfer!
• Activation cross sections: ???
Nuclear data activities have to be justified by demonstrating external interest