ENTRY 22656 20190327 22782265600000001 SUBENT 22656001 20190327 22782265600100001 BIB 19 170 2265600100002 TITLE Reaction mechanisms of fast neutrons on V-51 2265600100003 below 21 MeV. 2265600100004 AUTHOR (P.Reimer, V.Avrigeanu, A.J.M.Plompen, S.M.Qaim) 2265600100005 INSTITUTE (2ZZZGEL) Reimer, Avrigeanu, Plompen 2265600100006 (2GERJUL) Reimer, Qaim 2265600100007 (3RUMBUC) Avrigeanu 2265600100008 REFERENCE (J,PR/C,65,014604,2002) Main reference, data are 2265600100009 given 2265600100010 (J,NSTS,2,283,2002) Graphs are given. 2265600100011 ((P,INDC(GER)-048,8,2002)=(R,JUEL-3996,8,2002)) 2265600100012 (S,ISINN-8,159,2000) Prelim.data for V-0(n,x'alpha) 2265600100013 on fig.1 . 2265600100014 FACILITY 1(VDG,2ZZZGEL) 7-MV Van de Graaff accelerator, 2265600100015 Neutron Physics Unit, IRMM, Geel, Belgium 2265600100016 2(CYCLO,2GERJUL) Compact cyclotron CV-28, 2265600100017 Institute for Nuclear Chemistry, Forschungszentrum, 2265600100018 Juelich, Germany. 2265600100019 INC-SOURCE2(D-D) 1-H-2(D,N)2-He-3. 9-MeV deuterons incident on a 2265600100020 deuterium gas target. Primary neutrons with 11.7-MeV, 2265600100021 energy-scale uncertainty is 5 keV. 2265600100022 1(D-T) 1-H-3(D,N)2-He-4. Deuterons incident on a metal 2265600100023 titanium-tritium target (1.923 mg/cm**2 thick) 2265600100024 on a silver backing (0.5 mm thick).Primary neutrons 2265600100025 13.4 to 20.5 MeV. Energy scale uncertainty is 5 keV. 2265600100026 Deuteron energies of 1 - 4 MeV were used. 2265600100027 INC-SPECT -The neutron spectra from each of the sources used 2265600100028 were quasi-monoenergetic. 2265600100029 SAMPLE -All the vanadium samples were metallic with natural 2265600100030 isotopic abundance. Disks of 10- and 13-mm diameter 2265600100031 thickness 350-450 micrometer 2265600100032 Foils of aluminum, iron, nickel, indium, and niobium 2265600100033 with similar diameters were included along with 2265600100034 vanadium in multi-layer packets. Typical thicknesses 2265600100035 of auxiliary samples are less than 0.1 mm. The overall2265600100036 thickness of each packet was less than 2 mm. 2265600100037 Auxiliary samples served as primary or secondary 2265600100038 standards for neutron fluence determination and for 2265600100039 the purpose of determining corrections for low-energy 2265600100040 neutrons via the method of spectral indexing. 2265600100041 METHOD (ACTIV) Cross sections were measured using the neutron 2265600100042 activation method. Packets containing the vanadium 2265600100043 samples and various additional monitor foils were 2265600100044 irradiated in well-defined geometries near the targets2265600100045 of the accelerators. 2265600100046 (STTA) Stack-target irradiation . 2265600100047 DETECTOR (HPGE) Three high-purity germanium detectors. 2265600100048 (BF3) Boron-trifluoride detector in a long counter 2265600100049 configuration.3 2265600100050 (LONGC) Long counter for relative measurements. 2265600100051 MONITOR All measurements involving secondary standards were 2265600100052 ultimately referenced to the primary standard. 2265600100053 All relative measurements were ultimately normalized 2265600100054 to the primary standard. 2265600100055 (13-AL-27(N,A)11-NA-24,,SIG) Primary Standard 2265600100056 used directly or indirectly for all the measurements2265600100057 (49-IN-115(N,INL)49-IN-115-M,,SIG) 2265600100058 Spectral index component. This reaction is very 2265600100059 sensitive to the lowest-energy background neutrons. 2265600100060 (13-AL-27(N,P)12-MG-27,,SIG) Secondary 2265600100061 standard and spectral index component. 2265600100062 (26-FE-56(N,P)25-MN-56,,SIG) Secondary 2265600100063 standard and spectral index component. 2265600100064 (28-NI-58(N,P)27-CO-58,,SIG) Secondary 2265600100065 standard and spectral index component. 2265600100066 (41-NB-93(N,2N)41-NB-92-M,,SIG) 2265600100067 Secondary standard and spectral index component. 2265600100068 MONIT-REF (,H.Conde+,R,INDC(SEC)-101,1992) 2265600100069 (,M.Wagner+,B,PH-DAT,13,5,1990) Value for 1-st Monitor.2265600100070 (,A.B.Smith+,R,ANL-NDM-115,1990) 2265600100071 (,P.F.Rose+,R,ENDF-201,1991) 2265600100072 DECAY-MON (11-NA-24,14.9590HR,DG) 2265600100073 (12-MG-27,9.458MIN,DG) 2265600100074 (25-MN-56,2.5785HR,DG) 2265600100075 (41-NB-92-M,10.15D,DG) 2265600100076 (49-IN-115-M,4.486HR,DG) 2265600100077 (27-CO-58-G,70.86D,DG) 2265600100078 ANALYSIS -Cross-section ratios were derived from the 2265600100079 experimental data following application of various 2265600100080 corrections. Final cross sections were deduced from 2265600100081 the cross section ratios and the primary standard 2265600100082 cross sections. When the measurements were made 2265600100083 relative to secondary standards or to relative neutron2265600100084 fluence monitors, the data were normalized to the 2265600100085 primary standard by specific ratio measurements of the2265600100086 secondary standards to the primary standard or by 2265600100087 calibration of the relative monitors to these 2265600100088 standards. 2265600100089 CORRECTION - Most of correction procedures were standard. 2265600100090 The neutron scattering corrections were derived by 2265600100091 the Monte-Carlo method, computer code MCNP. 2265600100092 Corrections were largest for the D-T neutron source 2265600100093 measurements at 4-MeV deuteron energy. Correction was 2265600100094 11% for 49-In-115(n,inl)49-In-115-M reaction, 7% for 2265600100095 28-Ni-58(n,p)27-Co-58 Reaction, and less than 2% 2265600100096 for the remaining reactions. 2265600100097 -The low-energy neutron corrections were deduced using2265600100098 a representation of the neutron spectrum, evaluated 2265600100099 cross sections for the various spectral-index monitor 2265600100100 reactions, and estimates of the vanadium reaction 2265600100101 cross-section shape. The neutron spectrum determined 2265600100102 by time-of-flight measurement was transformed into 2265600100103 a few group representation which was then adjusted by 2265600100104 an application of the generalized least-squares 2265600100105 method that employed measured reaction rates for 2265600100106 several monitor reactions. 2265600100107 -The raw experimental data were corrected for the 2265600100108 following effects: 2265600100109 . Gamma-ray detection efficiency. 2265600100110 . Gamma-ray branching factors. 2265600100111 . Gamma-ray coincidence summing effects. 2265600100112 . Geometric effects. 2265600100113 . Gamma-ray absorption. 2265600100114 . Absorption and scattering of neutrons. 2265600100115 . Low-energy neutrons from the target. 2265600100116 . Decay of product nuclei. 2265600100117 . Fluctuations in neutron flux during the 2265600100118 irradiation period. 2265600100119 . Isotopic abundances. 2265600100120 . Sample chemical composition and impurities. 2265600100121 ERR-ANALYS (ERR-T) .Total Errors For the cross sections were 2265600100122 deduced by combining partial errors from 2265600100123 various sources in quadrature. Error sources 2265600100124 considered were: 2265600100125 (ERR-S,,25.) Max statistical counting errors - 25% 2265600100126 (ERR-1,,3.) Max uncertainty in detector 2265600100127 efficiencies - 3% 2265600100128 (ERR-2,,8.) Max uncertainty in gamma-emission 2265600100129 probability - 8% 2265600100130 (ERR-3,,8.) Max uncertainty in decay half lives - 8% 2265600100131 (ERR-4,,7.) Max uncertainty in coincidence summing 2265600100132 corrections - 7% 2265600100133 (ERR-5,,3.) Max uncertainty in the absorption of 2265600100134 gamma rays - 3% 2265600100135 (ERR-6,,1.) Max uncertainty due to sample mass - 1% 2265600100136 (ERR-7,,1.) Max uncertainty due to counting times - 1% 2265600100137 (ERR-8,,1.) Max uncertainty due to cooling times - 1% 2265600100138 (ERR-9,,6.) Max uncertainty due to gas-in/gas-out 2265600100139 background neutrons - 6% 2265600100140 (ERR-10,,16.) Max uncertainty due to breakup 2265600100141 neutrons - 16% 2265600100142 (ERR-11,,12.) Max uncertainty in low-energy neutron 2265600100143 corrections - 12% 2265600100144 (ERR-12,,0.5) Max uncertainty Due to Neutron Flux 2265600100145 fluctuations - 0.5 % 2265600100146 (ERR-13,,10.) Max uncertainty due to reference cross 2265600100147 section error - valid for Tc-99(n,n'gamma) 2265600100148 and In-115(n,n'gamma) reactions - 10% 2265600100149 (ERR-14) Most frequently occurring uncertainty due to 2265600100150 reference cross section error. 2265600100151 (EN-ERR) Error in the center of neutron energy line. 2265600100152 COMMENT -Monitor cross-section values at arbitrary neutron 2265600100153 energies were derived from tabulated values by means 2265600100154 of linear interpolation. 2265600100155 STATUS (TABLE) Data provided in tabular form by an author. 2265600100156 (APRVD) Manuscript obtained from an author. 2265600100157 HISTORY (20010713C) Compiled by the authors . 2265600100158 (20020710A) Corrected, J.O.S. 2265600100159 (20021128U) New references added. 2265600100160 (20030426U) Free text corrections,several new keywords,2265600100161 DECAY-DATA information. 2265600100162 (20060802U) Reference PR/C,65 ... corrected, SM 2265600100163 (20090617A) M.M. Reference ISINN-8,159 was added. 2265600100164 Free text was corrected to be human-readable. 2265600100165 ERR-1 -> ERR-S . 2265600100166 Maximal errors values were moved from COMMON block 2265600100167 into ERR-ANALYS lines. 2265600100168 (20131117U) SD: Ref. on 2001TSUKUB deleted according to2265600100169 MEMO CP-D/791. 2265600100170 (20190327U) SD: Year in ref. PR/C,65 corrected. 2265600100171 Pointer '3' deleted, not useful. 2265600100172 ENDBIB 170 0 2265600100173 COMMON 2 3 2265600100174 ERR-14 EN-ERR 2265600100175 PER-CENT KEV 2265600100176 3. 5. 2265600100177 ENDCOMMON 3 0 2265600100178 ENDSUBENT 177 0 2265600199999 SUBENT 22656002 20090617 22142265600200001 BIB 3 12 2265600200002 REACTION (23-V-0(N,X)21-SC-47,,SIG) 2265600200003 DECAY-DATA (21-SC-47,3.3492D,B-,,1.0, 2265600200004 DG,159.381,0.683) 2265600200005 COMMENT -The listed cross section data correspond to the 2265600200006 production of 21-Sc-47 by neutron bombardment of 2265600200007 elemental vanadium. According to the authors, below 2265600200008 15-MeV neutron energy the 23-V-50(N,A)21-Sc-47 2265600200009 reaction dominates the yield of 21-Sc-47. However, 2265600200010 above 15-MeV, the 23-V-51(N,N+A)47-Sc-47 is the 2265600200011 overwhelming contributor to 21-Sc-47 production, in 2265600200012 part because 23-V-51 is the dominant isotopic 2265600200013 component of elemental vanadium. 2265600200014 ENDBIB 12 0 2265600200015 NOCOMMON 0 0 2265600200016 DATA 4 9 2265600200017 EN EN-RSL-FW DATA ERR-T 2265600200018 MEV MEV MB MB 2265600200019 11.7 0.7 0.055 0.005 2265600200020 13.4 0.3 0.094 0.010 2265600200021 13.9 0.7 0.086 0.005 2265600200022 14.3 0.7 0.089 0.006 2265600200023 15.0 0.7 0.140 0.010 2265600200024 16.2 0.7 0.400 0.020 2265600200025 18.0 0.3 4.000 0.200 2265600200026 19.3 0.3 10.800 0.600 2265600200027 20.5 0.3 17.300 1.300 2265600200028 ENDDATA 11 0 2265600200029 ENDSUBENT 28 0 2265600299999 SUBENT 22656003 20030426 00002265600300001 BIB 2 6 2265600300002 REACTION (23-V-51(N,A)21-SC-48,,SIG) 2265600300003 DECAY-DATA (21-SC-48,43.67HR,B-,,1.0, 2265600300004 DG,175.4,0.0748, 2265600300005 DG,983.526,1.00, 2265600300006 DG,1037.5,0.976, 2265600300007 DG,1312.1,1.00) 2265600300008 ENDBIB 6 0 2265600300009 NOCOMMON 0 0 2265600300010 DATA 4 9 2265600300011 EN EN-RSL-FW DATA ERR-T 2265600300012 MEV MEV MB MB 2265600300013 11.7 0.7 8.3 0.8 2265600300014 13.4 0.3 14.1 1.2 2265600300015 13.9 0.7 15.4 1.1 2265600300016 14.3 0.3 14.2 1.2 2265600300017 15.0 0.7 18.2 1.7 2265600300018 16.2 0.3 19.8 1.8 2265600300019 18.0 0.3 21.1 1.8 2265600300020 19.3 0.3 19.8 1.8 2265600300021 20.5 0.3 14.6 1.6 2265600300022 ENDDATA 11 0 2265600300023 ENDSUBENT 22 0 2265600399999 SUBENT 22656004 20030426 00002265600400001 BIB 2 3 2265600400002 REACTION (23-V-51(N,P)22-TI-51,,SIG) 2265600400003 DECAY-DATA (22-TI-51,5.76MIN,B-,,1.0, 2265600400004 DG,320.076,0.931) 2265600400005 ENDBIB 3 0 2265600400006 NOCOMMON 0 0 2265600400007 DATA 4 2 2265600400008 EN EN-RSL-FW DATA ERR-T 2265600400009 MEV MEV MB MB 2265600400010 15.0 0.7 26. 2. 2265600400011 16.1 0.7 25. 2. 2265600400012 ENDDATA 4 0 2265600400013 ENDSUBENT 12 0 2265600499999 ENDENTRY 4 0 2265699999999