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potential nuclear data needs

Nuclear data for fusion applications an experimentalist's view Peter Rullhusen peter.rullhusen@ec.europa.eu. potential nuclear data needs. ITER: diagnostics activation (FW, BM, Div, vac. vessel, bio shielding) IFMIF: d-induced reactions n-induced reactions up to 60 MeV shielding

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potential nuclear data needs

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  1. Nuclear data for fusion applicationsan experimentalist's viewPeter Rullhusenpeter.rullhusen@ec.europa.eu

  2. potential nuclear data needs • ITER: • diagnostics • activation (FW, BM, Div, vac. vessel, bio shielding) • IFMIF: • d-induced reactions • n-induced reactions up to 60 MeV • shielding • radiation dammage • DEMO: • ch.p. induced reactions (d, t, 3He, a... ) • n-induced reactions up to 20 MeV

  3. diagnostics: • for example: • work carried out at IRMM in collab. with JET • activation measurements • g spectroscopy, partly in underground laboratory HADES • the following slides have been borrowed from a • presentation at IRMM by G. Bonheure Plasma Physics Laboratory Brussels, Belgium

  4. Blanket module Divertor module presentation G.Bonheure 28/09/2007 at IRMM ITER: Many engineering challenges • Change of extent of fusion research. • Many new problems to solve. • Millions of parts with very complex interfaces • Extremely high heat fluxes in first wall components, & materials under neutron irradiation • Unprecedented size of the super-conducting magnet and structures MAST JET ITER . Major radius (m) 0.9 3 6.1 Aspect ratio 1.3 2.5 3.0 Plasma current (MA) 1.4 4.8 15 Toroidal field (T) 0.5 3.5 5.3 Fusion power (MW) -- (16) 500 Pulse length (s) ~2 ~10 >1000 Q <<1 ~1 >10.

  5. presentation G.Bonheure 28/09/2007 at IRMM Access: ITER diagnostics are port-based where possible Each diagnostic port-plug contains an integrated instrumentation package

  6. presentation G.Bonheure 28/09/2007 at IRMM Neutron diagnostic systems: 4 types of systems Time-resolved total emission (non-collimated flux) Fusion power Absolute emission Calibration of time-resolved emission Time-integrated emission (fluence) 2D-cameras (collimated flux along camera viewing lines) Spatial distribution of emission tomography Spectrometers (collimated flux along radial and tangential viewing lines) Plasma temperature and velocity Plasma density Combination of these measurements characterizes the plasma as a neutron source

  7. presentation G.Bonheure 28/09/2007 at IRMM 1. Time-resolved neutron emission • Fission counters: • 238U and 235U counters embedded in moderator and led shield • Operate both in counting and current mode • Dynamic range: excellent (10 orders of magnitude) • 3 pairs installed at different positions around JET • Low sensitivity to X and g radiation • No discrimination between 2.5 and 14 MeV neutron emission • Calibrated originally in situ with californium 252Cf neutron source, periodically recalibrated using activation technique

  8. presentation G.Bonheure 28/09/2007 at IRMM 2. Time-integrated neutron emission • Neutron activation method Samples used as flux monitors are automatically transferred to 8Irradiation ends Sample activity measurements: 1) gamma spectroscopy measurements >>> most widely used reactions at JET: DD neutrons - 115In(n,n’)115mIn, DT neutrons - 28Si (n,p)28AL, 63Cu(n,2n)62Cu, 56Fe(n,p)56Mn >>>detectors : 3 NaI, HPGe (absolutely calibrated) 2) delayed neutron counting (235U,238U,232Th) >>>detectors: 2 stations with six 3He counters Calibration: accuracy of the time-resolved measurements is typically ~ 8-10% for both DD and DT neutrons (7% at best using delayed neutron method) – after several years of work !!

  9. presentation G.Bonheure 28/09/2007 at IRMM Other fusion products measurements • Confined fast ions and fusion products • Losses of fast ions and fusion products • d + d p (3024 keV) + t (1008 keV) • d + 3He  p (14681 keV) + a (3670 keV) • d + d  n (2450 keV) + 3He (817 keV) • d + t  n (14069 keV) + a (3517 keV) • + ICRF accelerated ions

  10. presentation G.Bonheure 28/09/2007 at IRMM How to measure confined ions with gammas? BGO NaI(Tl) Detection of  -ray lines due to nuclear reactions with fuel and with the main plasma impurities, Be and C protons D(p,)3He T(p,)4He 9Be(p,)10B 9Be(p,p’)9Be 9Be(p,)6Li 12C(p,p’)12C • Fast scintillators • LaBr3 :Ce (known as BrilLanCe): • Light yield  60,000 photons/MeV • Energy resolution - better than 3% • Decay times - < 20 ns (NaI: 250 ns) • LYSO: • Decay time  40ns • Better light output ( 32,000 photons/MeV ) • Slightly radioactive ( - and  - radiation) BGO

  11. presentation G.Bonheure 28/09/2007 at IRMM Activation probe • SAMPLES activation by charged particles • ANGULAR DISTRIBUTION (v magnetic field) of radionuclides : anisotropic for charged particles • Absolute measurements of time-integrated losses of charged particles • Recent results from D – 3He plasmas • 10B (p,α) 7Be , 7Li (p, n) 7Be • Detection of 14.6 MeV protons from threshold reaction • 48Ti(p,n)48V Eth : 5 MeV

  12. diagnostics (cont.) • work carried out at IRMM in collab. with JET: • activation of Ti, MgF2 and TiVAl alloy (g spectr. partly in underground lab) J. Gasparro et al., Appl. Rad. Isot. 64(2006) , G. Bonheure et al., Phys. Scr. 75 (2007) 769

  13. diagnostics (cont.) • activation of Ti, LiF, B4C and W (g spectr. partly in underground lab) E. Wieslander et al., to be publ.

  14. ITER • activation, rad. damage. • Example: • materials under consid. • for Blanket Module • Be • Al • Cu • Cr • Zr • Ti • SS • inconel

  15. structural materials • D. L. Smith, Neutron Reaction Data for IFMIF: example Fe

  16. Summary: what IRMM can contribute • n-induced reactions: • VdG: En ~ 1 MeV – 25 MeV • ch.p. induced reactions (p,d,a): up to 7 MeV (t,x)  look for inverse reactions • activation: half-lives > 10 min (external); very long: HADES ~ 10 ms – 1 s (beam chopper 1 Hz – 5 kHz) • high-resolution TOF: total, capture, (n,n') , (n,2n) • with installation of new ECR source (end 2007): • optimised for H, D, He+ and He++ at i>60 mA • possibility of accelerating 3He, 6Li (to be investigated) • proposed: 200 mA, 2 MV singletron for high-intensity measurements at low energies

  17. what IRMM can do (cont.) • example: • recent activ. meas. on W isotopes • V. Semkova, A. Plompen 182W(n,p)182Ta, 183W(n,x)182Ta 183W(n,p)183Ta, 184W(n,x)183Ta, 183W(n,n')183mW 184W(n,)181Hf, 184W(n,p)184Ta, 184W(n,2n)183mW 186W(n,)183Hf, 186W(n,x)185Ta, 186W(n,p)186Ta, 186W(n,2n)185mW

  18. what IRMM can do (cont.) • example: • upcoming capture and transmission meas. on W isotopes • NUDAME proposal:

  19. what IRMM can do (cont.) • FNG expt. for FENDL validation (contr. P. Batistoni): • Si, Nb, Ni, Fe, Sr, Al: which reactions? which enenergy range? • Be/Li2CO3 breeder: • 9Be(n,n) n angular distribution: new set-up for elast. scatt. • 9Be(n,2n) only cross sections remark: NRG (A. Hogenbirk) presented at NEMEA-4 workshop a method to carry out uncertainty calculations in arbitrary 3D geometries using MCNP as a radiation transport code.

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