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Nuclear Data Activities at PTB

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Presentation on theme: "Nuclear Data Activities at PTB"— Presentation transcript:

1 Nuclear Data Activities at PTB
R. Nolte Physikalisch-Technische Bundesanstalt Braunschweig Fachbereich 6.4

2 PTB Accelerator Facility
monenerg. neutron beams: T(d,n), T(p,n), 7Li(p,n) white neutron beams: 9Be(p,n), 9Be(d,n) 3.5 MV van-de-Graaf: p, d, a beams CV28 isochronous cyclotron: p (< 19 MeV), d (< 13.5 MeV), a (< 28 MeV) ns pulsing systems at both accelerator (Dt = 1.5 ns - 3 ns)

3 Reference 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

4 TOF spectrometer PE / Fe collimator fan flight path: 12 m (35 m)
optimized for 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”

5 Scattering Cross Section
D. Schmidt et al. TOF spectrometer: DE/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

6 28,29,30Si(n,n) and 28,29,30Si(n,n') without breakup correction Normalization by n-p scattering measurements Full Monte Carlo simulation Iterative adjustment of cross sections by comparison of calc. and exp. TOF spectra

7 Example: Si cross sections
D. Schmidt et al.: NDST 2001, Tsukuba

8 Activation Cross Sections
W. Mannhart et al. Reference reaction: 238U(n,f) Neutron source: D(d,n) Correction for activation by breakup neutrons Energy region: 7 MeV MeV Measured cross section (as of 2004) 24Mg(n,p)24Na 27Al(n,p)27Mg, 27Al(n,a)24Na 28Si(n,p)28Al, 20Si(n,a)27Mg 46Ti(n,p)46Sc, natTi(n,x)48Sc 51V(n,p)51Ti, 51V(n,a)38Sc 52 Cr(n,p)52V, 52Cr(n,p)52V, 52Cr(n,2n)51Cr 54Fe(n,p)54Mn, 54Fe(n,a)51Cr, 56Fe(n,p)56Mn 59Co(n,p)59Fe, 59Co(n,a)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

9 Example: Si activation cross sections
W. Mannhart et al.: NDST 2001, Tsukuba

10 Nuclear 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,5ng) by g-detection: together with IReS Strasbourg

11 UCL Neutron beam facility
Neutron production: 7Li(p,n) mm, 5 mm natLi targets Proton energy: 25 MeV - 65 MeV Proton current: 10 nA - 10mA External beam pulser: pulse separation 500 ns Three reference neutron beams: Epeak  33 MeV, 45 MeV, 60 MeV

12 TLABS neutron beam facility
Neutron production: 7Li(p,n), 5 mm target Proton energy: up to 200 MeV Proton current: max. 3 mA 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

13 Neutron reference beams (UCL and TLABS)
Uncertainty of peak fluence: DF 0/F 0 = (UCL) (w/o n-p cross section) = (TLABS) Relative peak fluence: F 0 /F = High-energy peaks broadened by time resolution of detectors

14 232Th(n,5ng)228Th-Experiment
Experiment UCL 07/04: 7Li(p,n)-Beam: Ep = 32, 36.5, 38, 40, 44, 48.5 MeV fluence: F RPT, 238U-FC spectral fluence: FE/F TOF, unfolding beam profile: F(r)/F TLD, image plate g-spectra+TOF: N(Eg) HPGe

15 Fission cross sections
Fission cross sections measured with PPFC‘s Fluence measurement with two RPT‘s (rel. to diff. n-p scattering cross section)

16 Future prospects at PTB
Running projects: Pb(n,n‘g) with 15N(p,n) source (En = 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


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