ENTRY 22986 20100713 22222298600000001 SUBENT 22986001 20100713 22222298600100001 BIB 14 96 2298600100002 TITLE Evaluation of the 103-Rh neutron cross-section data 2298600100003 in the unresolved resonance region for improved 2298600100004 criticality safety. 2298600100005 AUTHOR (L.C.Mihailescu, I.Sirakov, R.Capote, A.Borella, 2298600100006 K.H.Guber, S.Kopecky, L.C.Leal, P.Schillebeeckx, 2298600100007 P.Siegler, E.Soukhovitskii, R.Wynants, I.Ivanov) 2298600100008 REFERENCE (C,2007NICE,1,649,200704) Graphs. 2298600100009 #doi:10.1051/ndata:07617 2298600100010 (S,EUR-22794,153,2007) Graphs. 2298600100011 Proc.of the NEMEA-III Workshop 25-28 Oct.2006, 2298600100012 Borovets,Bulgaria, edited by A.J.M.Plompen. 2298600100013 2007NICE Book of Abstracts,page 11,paper#617, 200704. 2298600100014 INSTITUTE (2ZZZGEL) L.C.Mihailescu,I.Sirakov,A.Borella,S.Kopecky,2298600100015 P.Schillebeeckx,P.Siegler, R.Wynants. 2298600100016 (3ZZZIAE) R.Capote. 2298600100017 (1USAORL) K.H.Guber, L.C.Leal. 2298600100018 (4BLRJIE) E.Soukhovitskii. 2298600100019 FACILITY (LINAC,2ZZZGEL) Geel linear accelerator GELINA. 2298600100020 INC-SOURCE Neutron burst with full width at half maximum less 1ns.2298600100021 INC-SPECT Pulse white neutron spectrum from GELINA. 2298600100022 SAMPLE For transmission setup - the sample of 4.51E-2 at/barn 2298600100023 thickness was placed at half distance between neutron 2298600100024 detector and neutron source in computer driven sample 2298600100025 changer. 2298600100026 For capture measurement - two discs of metallic rhodium2298600100027 with thickness 3.37E-04 at/B and 1.877E-03 at/B were 2298600100028 used. 2298600100029 DETECTOR (GLASD) For the transmission measurements - 2298600100030 The neutrons were detected by 6mm thick NE912 Li-glass2298600100031 scintillator. 2298600100032 (BF3) BF3 proportional counters were used to monitor 2298600100033 the changes in integral neutron flux from GELINA. 2298600100034 (SCIN) For the capture measurements- two C6D6 detectors2298600100035 NE230 of 10cm diameter, 7.5cm height, placed at 125deg 2298600100036 with respect to neutron beam direction. 2298600100037 (IOCH) Neutron flux was permanently monitored by B-10 2298600100038 double Frisch-gridded ionization chamber, placed at 2298600100039 about 1m upstream sample. 2298600100040 METHOD (TOF) 2298600100041 Capture experiments, the flight path was 28.8 m, 800Hz2298600100042 repetition rate. 2298600100043 Transmission experiments, the flight path was 50 m, 2298600100044 400 Hz operation frequency. 2298600100045 (TRN) Transmission factor was determined by number of 2298600100046 counts, corrected for dead time of acquisition system. 2298600100047 Background was deduced from measurement with "black 2298600100048 resonance" filters. 2298600100049 In URR 6 keV -96 keV the transmission factor was 2298600100050 averaged in energy bins deltaE/E <30%. 2298600100051 Average total cross-section was obtained from average 2298600100052 transmission factor after correction for effect of 2298600100053 resonance structure. 2298600100054 For capture measurements - the total energy principle 2298600100055 with the weighting function technique was used. 2298600100056 Additional measurements with open beam configurations 2298600100057 were done for background determination. 2298600100058 Weighting functions were determined by MCNP simulations2298600100059 for each sample, including detailed description of 2298600100060 experimental setup. 2298600100061 In URR the capture yield was averaged in energy bins 2298600100062 with deltaE/E <30%. 2298600100063 REL-REF (N,,F.Frohner,R,GA-8380,1968) 2298600100064 SESH code see GA-8380 report of Gulf General Atomic. 2298600100065 (N,,J.F.Bresmeister,R,LA-13709-M,2000) 2298600100066 MCNP code see LA-13709-M report of Los Alamos 2298600100067 National Laboratory. 2298600100068 (R,22906001,A.Brusegan+,C,2004SANTA,1,953,2004) 2298600100069 Resonance parameters,previously determined from 2298600100070 simultaneous fit of capture and transmission data 2298600100071 in energy range from thermal up to 300 eV. 2298600100072 (M,,A.Borella+,J,NSE,152,1,2006) Procedure of data 2298600100073 analysis. 2298600100074 (N,,E.S.Soukhovitskii+,J,PR/C,72,024604,2005) 2298600100075 Relative reference for OMP calculation 2298600100076 (N,,R.Capote+,J,PR/C,72,064610,2005) 2298600100077 Relative reference for OMP calculation 2298600100078 (I,,A.Borella+,C,2007NICE,1,547,2007)Facility details. 2298600100079 #doi:10.1051/ndata:07366 2298600100080 CORRECTION Number of counts of detectors was corrected for dead 2298600100081 time of acquisition system. 2298600100082 For transmission measurements: 2298600100083 Correction factor for effect of resonance structures 2298600100084 was calculated with SEHS code.For thick samples the 2298600100085 correction factor may be reaching about 18% at 5 keV. 2298600100086 For capture measurements: 2298600100087 Normalization constant was determined in resolved 2298600100088 resonance region 100eV - 300eV using resonance analysis2298600100089 code REFIT and resonance parameters from third REL-REF.2298600100090 Average capture cross-section was corrected for effect 2298600100091 of multiple scattering and self-shielding using 2298600100092 iteratively code SESH.For thin sample correction less 2298600100093 0.5%. 2298600100094 ADD-RES (THEO) Dispersive coupled-channel OMP parameters 2298600100095 -Table 1. 2298600100096 HISTORY (20081015C) M.M. 2298600100097 (20100713U) M.M. R,EUR-22794S, -> EUR-22794, . 2298600100098 ENDBIB 96 0 2298600100099 NOCOMMON 0 0 2298600100100 ENDSUBENT 99 0 2298600199999 SUBENT 22986002 20081015 22042298600200001 BIB 2 7 2298600200002 REACTION (45-RH-103(N,TOT),,SIG,,AV) Average total cross-section2298600200003 STATUS (PRELM) Data are presented on Fig.2 of reference. 2298600200004 Preliminary results. 2298600200005 (UNOBT) E-mails were sent to the corresponding author 2298600200006 L.Mihailescu with request for data 20 Dec.2007, 2298600200007 02 Oct. 2008. 2298600200008 Reply - data are not ready for EXFOR data base. 2298600200009 ENDBIB 7 0 2298600200010 NOCOMMON 0 0 2298600200011 NODATA 0 0 2298600200012 ENDSUBENT 11 0 2298600299999 SUBENT 22986003 20081015 22042298600300001 BIB 2 7 2298600300002 REACTION (45-RH-103(N,G)45-RH-104,,SIG,,RTE/AV) 2298600300003 STATUS (PRELM) Data presented of Fig.3 of reference. 2298600300004 Preliminary results. 2298600300005 (UNOBT) E-mails were sent to the corresponding author 2298600300006 L.Mihailescu with request for data 20 Dec.2007, 2298600300007 02 Oct. 2008. 2298600300008 Reply - data are not ready for EXFOR data base. 2298600300009 ENDBIB 7 0 2298600300010 NOCOMMON 0 0 2298600300011 NODATA 0 0 2298600300012 ENDSUBENT 11 0 2298600399999 SUBENT 22986004 20081015 22042298600400001 BIB 4 30 2298600400002 REACTION 1(45-RH-103(N,EL)45-RH-103,POT,RAD)Potential scat.radius2298600400003 2(45-RH-103(N,0),,D) Average level spacing. 2298600400004 3(45-RH-103(N,TOT),,STF) Neutron strength function. 2298600400005 4(45-RH-103(N,G),,WID,,AV) Average gamma width. 2298600400006 5(45-RH-103(N,G),,STF) Gamma strength function. 2298600400007 ASSUMED (ASSUM,45-RH-103(N,G),,WID,,AV) Average gamma width for2298600400008 s-wave and d-wave (l=0 and 2) was assumed constant 2298600400009 of value 165.meV, based on values from resolved 2298600400010 resonance region, defined in REL-REF 2298600400011 A.Brusegan+,C,2004SANTA,1,953,2004. 2298600400012 ANALYSIS (SHAPE) Average partial cross-sections in URR were 2298600400013 expressed in terms of transmission coefficients by 2298600400014 applying Hauser-Feshbach theory with width fluctuation 2298600400015 correction factor -similar in 4th REL-REF. 2298600400016 Isospin dependent coupled-channel optical model 2298600400017 potential containing a dispersive term with nonlocal 2298600400018 contribution was derived from fits to the entire 2298600400019 neutron and proton scattering data set by methodology 2298600400020 of 5th and 6th REL-REFs. 2298600400021 Customary coupled-channels calculations were performed 2298600400022 by coupling first 6 states of ground state up to 2298600400023 1.41MeV excitation energy. Link to derived DCCOM was 2298600400024 used to determine energy dependence of potential 2298600400025 scattering radius and of neutron strength functions, 2298600400026 which was of order of few percent on range of 6-96 keV.2298600400027 Average resonance parameters were resulted from present2298600400028 fit. 2298600400029 STATUS (TABLE) From Table 2 of reference. Preliminary results.2298600400030 (DEP,22986002) 2298600400031 (DEP,22986003) 2298600400032 ENDBIB 30 0 2298600400033 COMMON 3 3 2298600400034 EN-RES-MIN EN-RES-MAX ASSUM 2298600400035 KEV KEV MILLI-EV 2298600400036 6. 96. 165.0 2298600400037 ENDCOMMON 3 0 2298600400038 DATA 6 3 2298600400039 MOMENTUM L DATA 1DATA 2DATA 3DATA 4DATA 52298600400040 NO-DIM FERMI EV NO-DIM MILLI-EV NO-DIM 2298600400041 0. 6.44 23.14 0.60E-04 7.13E-032298600400042 1. 4.99E-04 123.4 2298600400043 2. 0.46E-04 2298600400044 ENDDATA 5 0 2298600400045 ENDSUBENT 44 0 2298600499999 ENDENTRY 4 0 2298699999999