ENTRY 30417 20090310 31353041700000001 SUBENT 30417001 20090310 31353041700100001 BIB 16 56 3041700100002 INSTITUTE (2GERZFK) 3041700100003 REFERENCE (J,IP,13,(1),15,197701) 3041700100004 AUTHOR (G.Pfrepper) 3041700100005 TITLE -Determination of cross-sections of threshold reactions3041700100006 with fission neutrons,study of Cl-35(n,a)P-32 reaction-3041700100007 FACILITY (REAC,2GERZFK) 3041700100008 Research reactor at ZFK, Rossendorf. 3041700100009 INC-SOURCE (REAC) 3041700100010 INC-SPECT The flux ratio of thermal to fission neutrons,F(t)/F(S)3041700100011 was determined using 27Al(n,a)24Na and 24Mg(n,p)24Na 3041700100012 (for fiss.neutrons) and Na-23(n,g)Na-24(for thermal) 3041700100013 and their cadmium ratios. 3041700100014 Reaction Effect.n-energy X-section Cd-ratio 3041700100015 Mg-24(n,p)Na-24 7.2 MeV 1.53mb 1. 3041700100016 Al-27(n,a)Na-24 8.8 MeV 0.725mb 1. 3041700100017 Ref. A.Fabry, rep.BLG-465 (1972). 3041700100018 Compiler's note = 3041700100019 For limit of 'MONIT' number, those values are not 3041700100020 included in data section.- 3041700100021 SAMPLE 50-100 mg NH(4)-Cl or KCl, and with 10-15 Mg (NH(4))* 3041700100022 2-HPO(4) as phosphor standard sample,in quartz ampoule.3041700100023 METHOD (CHSEP,MOMIX) 3041700100024 (n,g) reaction leading to the same daughter product 3041700100025 was used for comparison.(Cl-35(n,a)P-32, P-31(n,g)P-32)3041700100026 Only relative measurement of the activities of the 3041700100027 sample and standard is to be performed. 3041700100028 DETECTOR (GELI) 18 cm3 Ge(Li) detector with a 4096 channel pulse3041700100029 height analyzer (Nuclear Chicago). 3041700100030 .Bell-shape counter VA-Z-320 and radiation detectors 3041700100031 VA-V-100, VA-G-120 and VA-G-24A,( VEB Messelektronik, 3041700100032 Dresden), for beta counting. 3041700100033 ANALYSIS The cross-section of Cl-35(n,a)p-32 for fission- 3041700100034 neutron, sig(S) is deduced from the following equation,3041700100035 sig(S)=sig(t)*(F(t)/F(S))*(1/p)*(r/(r-1))*(1/r'), 3041700100036 where 3041700100037 sig(t)- (n,g) cross-section for 'thermal' neutrons, 3041700100038 F(t)/F(S)- flux ratio of thermal to fission neutrons, 3041700100039 p- isotopic disturbing coef. Which can be determined 3041700100040 to measure the relative activity of target and 3041700100041 standard, 3041700100042 r- cadmium ratio of (n,g) reaction, 3041700100043 r'- cadmium ratio of threshold reaction. 3041700100044 Cadmium ratios of P-31(n,g)P-32 and Cl-35(n,a)P-32 3041700100045 were determined to be 60 and 1 respectively. 3041700100046 PART-DET (DG,B-) 3041700100047 2.75 MeV gamma peak of Na-24 and P-32 beta activity. 3041700100048 COMMENT Compiler's note === The author has published, with 3041700100049 same technique, using the reactor at Institut fuer 3041700100050 Kernforschung u. Kernenergetik Sofia, the results of 3041700100051 several reactions. === 3041700100052 STATUS (APRVD) Approved by Pfrepper(through Seeliger,78/04/25)3041700100053 HISTORY (19770714C) KO.- 3041700100054 (19790925U) KO.-'Aprvd' added.- 3041700100055 (20090310A) SD:Updated to new date formats,lower case. 3041700100056 ERR-ANALYS (DATA-ERR) Standard deviation of the mean value of 3041700100057 14 different experimental run. 3041700100058 ENDBIB 56 0 3041700100059 NOCOMMON 0 0 3041700100060 ENDSUBENT 59 0 3041700199999 SUBENT 30417002 20090310 31353041700200001 BIB 4 11 3041700200002 REACTION (17-CL-35(N,A)15-P-32,,SIG,,FIS) 3041700200003 MONITOR ((MONIT1)15-P-31(N,G)15-P-32,,SIG,,MXW) = 190 mb, 3041700200004 Cd-ratio=60. 3041700200005 ((MONIT2)16-S-32(N,P)15-P-32,,SIG,,FIS) = 69 mb, 3041700200006 Cd-ratio =1. 3041700200007 ((MONIT3)11-NA-23(N,G)11-NA-24,,SIG,,MXW) = 528 mb, 3041700200008 Cd-ratio=62 3041700200009 MONIT-REF ((MONIT1),R.SHER,R,IAEA-156,1,1974) 3041700200010 ((MONIT2),A.FABRY,R,BLG-465,1972) 3041700200011 ((MONIT3),R.SHER,R,IAEA-156,1,1974) 3041700200012 STATUS (TABLE) Data from Isotopenpraxis,13(1977)15. 3041700200013 ENDBIB 11 0 3041700200014 COMMON 3 3 3041700200015 MONIT1 MONIT2 MONIT3 3041700200016 MB MB MB 3041700200017 1.9000E+02 6.9000E+01 5.2800E+02 3041700200018 ENDCOMMON 3 0 3041700200019 DATA 3 1 3041700200020 EN-DUMMY DATA DATA-ERR 3041700200021 MEV MB MB 3041700200022 2.0000E+00 2.6000E+01 2.6000E+00 3041700200023 ENDDATA 3 0 3041700200024 ENDSUBENT 23 0 3041700299999 ENDENTRY 2 0 3041799999999