100 likes | 190 Views
Ilias/ N3/WG5 meeting. Maryvonne De J é sus. Neutron studies in Edelweiss “Suite”. Valenc ia (Espana). 15/04/2005. Plan. Germanium nuclear recoil angular distribution in Geant 3 Rock spectra propagation with Geant 3 and MCNPX. Correction :.
E N D
Ilias/N3/WG5 meeting Maryvonne De Jésus Neutron studies in Edelweiss “Suite” Valencia (Espana) 15/04/2005
Plan • Germanium nuclear recoil angular distribution in Geant 3 • Rock spectra propagation with Geant 3 and MCNPX
Correction : Code THALYS used to calculate differential cross sections in the CM with Koning-Delaroche set of parameters and spherical nuclei (O. Bersillon , private communication : Proper reference to the code TALYS A.J. Koning, S. Hilaire and M. Duijvestijn, TALYS: Comprehensive nuclear reaction modeling Proceedings of the International Conference on Nuclear Data for Science and Technology - ND2004 Sep. 26 - Oct. 1, Santa Fe, USA, to be published Proper reference to the optical model parameters for germanium A.J. Koning and J.P. Delaroche Local and global nucleon optical models from 1 keV to 200 MeV Nuclear Physics A 713 (2003) 231-310) Angular distribution with Geant 321
Modification in the SUBROUTINE COLISN IF (KZI.eq.32) call MYCANG
Edelweiss-I neutron calibration with 232Cf Simulation with modified Geant-321 • Ratio Data/Simulation [15 , 200 ] keV : 1.5 • Data vs. simulation : good agreement in the nuclear recoil spectra
Propagation of neutrons through the LSM rock : Geant3 and MCNPX • Initial rock spetra : • Spectrum calculated by V.Chazal (Astroparticle Phys.9 (1996)163-172 ) • Neutron production in the rock : f=1.143x10e-7 n/s/cm3 • Neutron flux in lab reevaluated • (G.Chardin et al IDM 2002 ) En > 2 MeV : f= 1.6x10-6 n/s/cm2 • Spectrum calculated by R.Lemrani with code SOURCES : • Neutron production in the rock : f=1.133x10e-7 n/s/cm3 Measured rock composition : Density : r=2.65 g/cm3 Rock composition introduced in Geant 3
Rock Lab Air or PE Geometries for simulations with geant3 : Plane geometry
Geant 3 Geant 3 Geant 3 V.Chazal V.Chazal V.Chazal SOURCES SOURCES SOURCES MCNPX MCNPX MCNPX Results : LSM Geometry with scatterring LSM Geometry with scatterring LSM Geometry without scatterring Plane Geometry
Results : Plane + 60 cm polyethylene : reduction factor of ~ 15000 f= ~ 13x10-10
Summary and outlook • Relatively good agreement between the 2 codes G3 and MCNP • Continue code comparisons to understand the remaining • discrepancies • Propagate the lab n spetrum through EDW-1 and EDW-II • geometries to get correct nuclear recoil spectra for Germanium .