ENTRY 31518 20020301 00003151800000001 SUBENT 31518001 20020301 00003151800100001 BIB 16 57 3151800100002 INSTITUTE (3BZLIPE) 3151800100003 REFERENCE (J,RCA,89,419,2001) 3151800100004 AUTHOR (N.L.MAIDANA,M.S.DIAS,M.F.KOSKINAS) 3151800100005 TITLE Measurement of the thermal neutron capture cross 3151800100006 section and resonance integral of Am-241 3151800100007 METHOD (ACTIV) Activation method with measuring the 3151800100008 activity with 4Pi-beta-gamma coincidence system 3151800100009 applying the tracer technique. 30 min irradiation time 3151800100010 for thermal cross section measurements and 60 min for 3151800100011 resonance integral measurements. Time interval between 3151800100012 the end of irradiation and counting is about 60 min. 3151800100013 2 irradiations for thermal cross section determination 3151800100014 After irradiation the sample 3151800100015 was diluted in 1 M HNO3 solution and activity was 3151800100016 measured in 4-Pi-beta-gamma system for source prepared.3151800100017 Details are given in the paper 3151800100018 FACILITY (REAC) IEA-R1 pool-type IPEN research reactor operating3151800100019 at 2 MW power 3151800100020 INC-SOURCE (REAC) Core of the reactor 3151800100021 INC-SPECT Flux of thermal neutrons 2.8E+12 n/cm*2/sec with 3151800100022 epithermal index in the Westcott r*sqrt(T/T0) 3151800100023 convention equals to 0.036. A slight variation in the 3151800100024 epithermal neutron spectrum with respect to the usual 3151800100025 1/E form was observed 3151800100026 DETECTOR (COIN,PROPC,NAICR) gas flow proportional counter with 3151800100027 4-Pi geometry (90%Ar + 10%CH4, 0.1 MPA) as the beta 3151800100028 detector in the coincidence with 3151800100029 two 7.6*7.6-cm NaI(Tl) scintillation counter 3151800100030 as gamma-detector. The selected gamma-channel window 3151800100031 covered both 1173 and 1332 keV peaks of Co-60 3151800100032 SAMPLE 40 MBq Am target sealed inside a double 0.2 mm thick 3151800100033 polyethylene and placed inside polyethylene rabbit 3151800100034 DECAY-MON (79-AU-198,2.6943D,DG,411.8044,.9557) 3151800100035 (27-CO-60,1925.5D,DG,1173.238,.99857,DG,1332.502, 3151800100036 .99983) 3151800100037 DECAY-DATA (95-AM-241,1.5785E+5D,DG,59.537,.360) 3151800100038 (95-AM-242-G,16.02HR,B-,,.827) 3151800100039 (95-AM-242-G,16.02HR,DG,42.13,4.62E-6, 3151800100040 DG,44.52,7.99E-4) 3151800100041 Upper theoretical estimates for emission probabilities 3151800100042 (95-AM-242-M,141.YR,DG,44.63,.00173) Theoretical 3151800100043 estimate for emission probability (upper boundary) 3151800100044 CORRECTION Corrected for accidental coincidence, dead time and 3151800100045 decay. 3151800100046 For thermal cross section: corrected at the 3151800100047 contribution in the activation from 0.308 eV and 0.573 3151800100048 eV resonances, at the departure of the epithermal 3151800100049 neutron spectrum from 1/E dependence and at the 3151800100050 non-ideal Cd cut-off of thermal neutrons with Monte 3151800100051 Carlo simulation calculations. 3151800100052 For resonance integral, the Monte Carlo simulated 3151800100053 corrections was equal to 7.5%, corrected at resonance 3151800100054 self-shielding 3151800100055 ERR-ANALYS (ERR-T) Full covariance analysis between parameters 3151800100056 and cross section values 3151800100057 STATUS Data from p.422 of main reference. 3151800100058 HISTORY (20020214C) Compiled by VP 3151800100059 ENDBIB 57 0 3151800100060 NOCOMMON 0 0 3151800100061 ENDSUBENT 60 0 3151800199999 SUBENT 31518002 20020213 00003151800200001 BIB 4 15 3151800200002 REACTION (95-AM-241(N,G)95-AM-242-G,,SIG) 2200 m/s cross sect. 3151800200003 ANALYSIS Compiler considers 3151800200004 measured "thermal" cross section given in this work 3151800200005 as equal to the value at 0.0253 eV energy point 3151800200006 because corrections at deviation of cross sections 3151800200007 from 1/V and spectrum in epithermal region from 3151800200008 1/E dependence are introduced 3151800200009 MONITOR ((MONIT1)79-AU-197(N,G)79-AU-198,,SIG) Au-Al alloy 3151800200010 with 0.1% gold in form of foils irradiated (in pairs 3151800200011 Co(0.475%)-Al alloy sample in form of wire with Co used3151800200012 as tracer) with and without 0.5 mm thick Cd shield. 3151800200013 The content of gold was checked by simultaneous 3151800200014 irradiation with pure gold foils 3151800200015 ((MONIT2)27-CO-59(N,G)27-CO-60,,SIG) as tracer 3151800200016 MONIT-REF (,J.H.BAARD+,B,BAARD,,1989) 3151800200017 ENDBIB 15 0 3151800200018 NOCOMMON 0 0 3151800200019 DATA 7 1 3151800200020 EN DATA ERR-T MONIT1 MONIT1-ERR MONIT2 3151800200021 MONIT2-ERR 3151800200022 EV B B B B B 3151800200023 B 3151800200024 0.0253 602. 9. 98.8 0.3 37.2 3151800200025 0.2 3151800200026 ENDDATA 6 0 3151800200027 ENDSUBENT 26 0 3151800299999 SUBENT 31518003 20020213 00003151800300001 BIB 3 10 3151800300002 REACTION (95-AM-241(N,G)95-AM-242-G,,RI) EN-MIN is lower limit 3151800300003 of integration. Upper limit is 1 MeV 3151800300004 MONITOR ((MONIT1)79-AU-197(N,G)79-AU-198,,RI) Au-Al alloy 3151800300005 with 0.1% gold in form of foils irradiated (in pairs 3151800300006 Co(0.475%)-Al alloy sample in form of wire with Co used3151800300007 as tracer) with and without 0.5 mm thick Cd shield. 3151800300008 The content of gold was checked by simultaneous 3151800300009 irradiation with pure gold foils 3151800300010 ((MONIT2)27-CO-59(N,G)27-CO-60,,RI) as tracer 3151800300011 MONIT-REF (,J.H.BAARD+,B,BAARD,,1989) 3151800300012 ENDBIB 10 0 3151800300013 NOCOMMON 0 0 3151800300014 DATA 8 1 3151800300015 EN-MIN EN-MAX DATA ERR-T MONIT1 MONIT1-ERR 3151800300016 MONIT2 MONIT2-ERR 3151800300017 EV MEV B B B B 3151800300018 B B 3151800300019 0.5 1. 1665. 91. 1560. 40. 3151800300020 75.5 1.5 3151800300021 ENDDATA 6 0 3151800300022 ENDSUBENT 21 0 3151800399999 ENDENTRY 3 0 3151899999999