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