ENTRY 21724 20200803 22902172400000001 SUBENT 21724001 20200803 22902172400100001 BIB 11 52 2172400100002 TITLE The (n-th,alpha)-reaction on U-233,U-235 and U-238 2172400100003 and determination of the U-238(n-th,alpha)Th-235 2172400100004 reaction characteristics 2172400100005 AUTHOR (C.Wagemans,E.Allaert,A.De Clerq,P.D'Hondt, 2172400100006 A.Deruytter,G.Barreau,A.Emsallem) 2172400100007 REFERENCE (J,NP/A,362,1,1981) Experimental method, data 2172400100008 (C,82ANTWER,,147,1982) Final data. 2172400100009 (C,81GRENOB,,457,1981) 2172400100010 (T,D'HONDT,1981) Experimental method and preliminary 2172400100011 results for U-238,U-233 and Pu-239. - In Dutch. - 2172400100012 INSTITUTE (2FR ILL) Experimental site, G.B. 2172400100013 (2BLGMOL) C.W.,E.A. 2172400100014 (2BLGGHT) C.W.,E.A.,A.D.,P.D.,A.D. 2172400100015 (2FR LYO) A.E. 2172400100016 FACILITY (REAC,2FR ILL) 87 m curved neutron guide of the 2172400100017 high flux reactor. Flux of 6.E+8 n/cm**2/sec, 2172400100018 cadmium ratio of 1.E+6, gamma flux reduced by a 2172400100019 factor of 1.E+6. 2172400100020 INC-SOURCE (REAC) 2172400100021 INC-SPECT Thermal Maxwellian neutron spectrum from HFR. 2172400100022 METHOD (EDE) Alpha particles selected by telescope 2172400100023 detector. 2172400100024 In the case of U-233 and U-238 no aluminium absorber 2172400100025 was placed in between sample and detector. In the case2172400100026 of U-235 an aluminium foil was used to protect the 2172400100027 de-detector against the fission fragments and the 2172400100028 LRA's. 2172400100029 In the case of Th-232 and Pu-239 it was not specified 2172400100030 if there was such an absorber. 2172400100031 DETECTOR (TELES,SIBAR,SIBAR) Telescope detector, consisting of 2172400100032 two Si(Au) surface barrier detectors. 2172400100033 The dE-detector was fully depleted, with a thickness 2172400100034 of 26.7 microns, an active area of 300 mm**2, an 2172400100035 energy resolution of 35 keV for 5.5 MeV alphas. 2172400100036 The E-detector had a thickness of 700 microns, an 2172400100037 active area of 450 mm**2, and a resolution of 25 keV 2172400100038 for 5.5 MeV alphas. 2172400100039 The detectors were calibrated with the alpha lines of 2172400100040 the spontaneous decay of the U-isotopes, the 2.055 MeV2172400100041 alpha line from Li-6(n,t) and the 9.43 MeV alpha line 2172400100042 from the Nd-143(n,alpha) reaction. 2172400100043 CORRECTION For the energy losses in the aluminium absorber. 2172400100044 HISTORY (19810204C) G.C. 2172400100045 (19830118A) G.C., References added, 2172400100046 Subents 007 and 008 added. 2172400100047 (19830318A) A.P.T. Grenoble conference reference added.2172400100048 (20090401A) Date is corrected. BIB information added. 2172400100049 Upper case to low converted. 2172400100050 (20200803A) SD: REACTION code corrected in Subent 002. 2172400100051 Small corrections in all Subents. Subent 006 deleted 2172400100052 (Not reaction data. This value is reported for 2172400100053 derivation of the 235Th mass.). 2172400100054 ENDBIB 52 0 2172400100055 COMMON 1 3 2172400100056 EN-DUMMY 2172400100057 EV 2172400100058 2.53E-02 2172400100059 ENDCOMMON 3 0 2172400100060 ENDSUBENT 59 0 2172400199999 SUBENT 21724002 20200803 22902172400200001 BIB 7 15 2172400200002 REACTION (92-U-233(N,F)2-HE-4,TER,KE,,MXW) 2172400200003 Position of the peak of the LRA spectrum. 2172400200004 SAMPLE Prepared at CBNM, Geel by evaporation under vacuum 2172400200005 of U-F(4) on a thin backing foil. It contained 2172400200006 99.7617% U-233 and had a thickness of 4.6 mu-g U/cm2. 2172400200007 ANALYSIS Fit of a Gaussian distribution through the higher 2172400200008 energy part of the LRA spectrum. 2172400200009 COMMENT The lower energy part of the LRA spectrum deviates 2172400200010 from a Gaussian. 2172400200011 ERR-ANALYS (ERR-S) Statistical error 2172400200012 STATUS (TABLE) Text on p.4 of Nuc.Phys.,A362(1981)1 2172400200013 HISTORY (20200803A) SD: SF4=He-4; SF6=AKE -> KE; SF7=A deleted 2172400200014 from REACTION code. STATUS updated. Subent 006 deleted 2172400200015 (This value is reported for derivation of the 2172400200016 235Th mass). 2172400200017 ENDBIB 15 0 2172400200018 NOCOMMON 0 0 2172400200019 DATA 2 1 2172400200020 DATA ERR-S 2172400200021 MEV MEV 2172400200022 16. 0.2 2172400200023 ENDDATA 3 0 2172400200024 ENDSUBENT 23 0 2172400299999 SUBENT 21724003 20200803 22902172400300001 BIB 9 20 2172400300002 REACTION (92-U-233(N,A)90-TH-230,,SIG,,MXW) 2172400300003 SAMPLE Prepared at CBNM, Geel by evaporation under vacuum 2172400300004 of U-F(4) on a thin backing foil. It contained 2172400300005 99.7617 atom percent U-233 and had a thickness of 2172400300006 4.6 mu-g U/cm**2. 2172400300007 ANALYSIS Fit of the LRA background. 2172400300008 MONITOR (92-U-235(N,F),,SIG) 2172400300009 MONIT-REF (20143002,A.J.Deruytter+,J,JNE,27,645,1973) 2172400300010 COMMENT The lower energy part of the LRA spectrum deviates 2172400300011 from a Gaussian. 2172400300012 Assumption of a Gaussian shape may therefore introduce2172400300013 large errors in the (n,alpha)-results of other authors2172400300014 Also the background may be a reason for the discrepancy2172400300015 between the present results and those of other authors2172400300016 Compared with statistical model calculation. 2172400300017 ERR-ANALYS An upper limit of the cross section is given, which 2172400300018 is determined by the statistical accuracy. 2172400300019 (1 sigma confidence level). 2172400300020 STATUS (TABLE) Table 2 from Nuc.Phys.,A362(1981)1 2172400300021 HISTORY (20200803U) SD: STATUS updated. 2172400300022 ENDBIB 20 0 2172400300023 NOCOMMON 0 0 2172400300024 DATA 2 1 2172400300025 DATA-MAX MONIT 2172400300026 MB B 2172400300027 0.300 587.6 2172400300028 ENDDATA 3 0 2172400300029 ENDSUBENT 28 0 2172400399999 SUBENT 21724004 20200803 22902172400400001 BIB 9 22 2172400400002 REACTION (92-U-235(N,A)90-TH-232,,SIG,,MXW) 2172400400003 SAMPLE Prepared at CBNM,Geel by evaporation under vacuum of 2172400400004 U-F(4) on a thin backing foil. 2172400400005 It contained 0.1699 atom percent U-234, 99.4759 atom 2172400400006 percent U-235, 0.0273 atom percent U-236, and 2172400400007 0.3269 atom percent U-238. Its thickness was 150. 2172400400008 mu-g U/cm**2. 2172400400009 ANALYSIS Fit of the LRA background spectrum. 2172400400010 MONITOR (92-U-235(N,F),,SIG) 2172400400011 MONIT-REF (20143002,A.J.Deruytter+,J,JNE,27,645,1973) 2172400400012 COMMENT The lower energy part of the LRA spectrum deviates 2172400400013 from a Gaussian. 2172400400014 Assumption of a Gaussian shape may therefore introduce2172400400015 large errors in the (n,alpha)-results of other authors2172400400016 Also the background may be a reason for the discrepancy2172400400017 between the present results and those of other authors2172400400018 Compared with statistical model calculation. 2172400400019 ERR-ANALYS Upper limit of the cross section given, determined by 2172400400020 the statistical accuracy at a 1 sigma confidence 2172400400021 level. 2172400400022 STATUS (TABLE) Table 2 from Nuc.Phys.,A362(1981)1 2172400400023 HISTORY (20200803U) SD: STATUS updated. 2172400400024 ENDBIB 22 0 2172400400025 NOCOMMON 0 0 2172400400026 DATA 2 1 2172400400027 DATA-MAX MONIT 2172400400028 MB B 2172400400029 0.100 587.6 2172400400030 ENDDATA 3 0 2172400400031 ENDSUBENT 30 0 2172400499999 SUBENT 21724005 20200803 22902172400500001 BIB 9 16 2172400500002 REACTION (92-U-238(N,A)90-TH-235,,SIG,,MXW) 2172400500003 SAMPLE Prepared at CBNM, Geel by evaporation under vacuum 2172400500004 of U-F(4) on a thin backing foil. It contained 2172400500005 less than 0.00007 atom percent U-234, 0.0014 atom 2172400500006 percent U-235, less than 0.00007 atom percent U-236, 2172400500007 and 99.9986 atom percent U-238. Its thickness was 2172400500008 94.9 micrograms U/cm**2. 2172400500009 MONITOR (92-U-235(N,F),,SIG) 2172400500010 MONIT-REF (20143002,A.J.Deruytter+,J,JNE,27,645,1973) 2172400500011 MISC-COL (MISC) Q-value 2172400500012 COMMENT .The unknown mass of Th-235 was determined to be 2172400500013 235.04751 amu. 2172400500014 .The Q-beta value was determined to be 1.92 +- 0.16 MeV2172400500015 ERR-ANALYS (ERR-S) Statistical error. 1 sigma. 2172400500016 STATUS (TABLE) Table 2 from Nuc.Phys.,A362(1981)1 2172400500017 HISTORY (20200803U) SD: STATUS updated. 2172400500018 ENDBIB 16 0 2172400500019 NOCOMMON 0 0 2172400500020 DATA 5 1 2172400500021 DATA ERR-S MONIT MISC MISC-ERR 2172400500022 MB MB B MEV MEV 2172400500023 1.5E-03 5.E-04 587.6 8.7 5.E-02 2172400500024 ENDDATA 3 0 2172400500025 ENDSUBENT 24 0 2172400599999 NOSUBENT 21724006 20200803 22902172400600001 SUBENT 21724007 20200803 22902172400700001 BIB 9 17 2172400700002 REACTION (90-TH-232(N,A)88-RA-229,,SIG,,MXW) 2172400700003 SAMPLE No details given. 2172400700004 ANALYSIS Fit of the LRA background. 2172400700005 MONITOR (92-U-235(N,F),,SIG) 2172400700006 MONIT-REF (20143002,A.J.Deruytter+,J,JNE,27,645,1973) 2172400700007 COMMENT The lower energy part of the LRA spectrum deviates 2172400700008 from a Gaussian. 2172400700009 Assumption of a Gaussian shape may therefore introduce2172400700010 large errors in the (n,alpha)-results of other authors2172400700011 Also the background may be a reason for the 2172400700012 discrepancy between the present results and those of 2172400700013 other authors. 2172400700014 ERR-ANALYS An upper limit of the cross section is given, which 2172400700015 is determined by the statistical accuracy. 2172400700016 (1 sigma confidence level). 2172400700017 STATUS (TABLE) Table II from 82ANTWER,,147 2172400700018 HISTORY (20200803U) SD: STATUS updated. 2172400700019 ENDBIB 17 0 2172400700020 NOCOMMON 0 0 2172400700021 DATA 2 1 2172400700022 DATA-MAX MONIT 2172400700023 MB B 2172400700024 0.100 587.6 2172400700025 ENDDATA 3 0 2172400700026 ENDSUBENT 25 0 2172400799999 SUBENT 21724008 20200803 22902172400800001 BIB 9 19 2172400800002 REACTION (94-PU-239(N,A)92-U-236,,SIG,,MXW) 2172400800003 SAMPLE Pu-acetate layer electrosprayed onto a mylar 2172400800004 backing. It contained 99.956% of Pu-239. 2172400800005 The thickness of the layer was 5. mu-g/cm**2. 2172400800006 ANALYSIS Fit of the LRA background. 2172400800007 MONITOR (92-U-235(N,F),,SIG) 2172400800008 MONIT-REF (20143002,A.J.Deruytter+,J,JNE,27,645,1973) 2172400800009 COMMENT The lower energy part of the LRA spectrum deviates 2172400800010 from a Gaussian. 2172400800011 Assumption of a Gaussian shape may therefore introduce2172400800012 large errors in the (n,alpha)-results of other authors2172400800013 Also the background may be a reason for the 2172400800014 discrepancy between the present results and those of 2172400800015 other authors. 2172400800016 ERR-ANALYS An upper limit of the cross section is given, which 2172400800017 is determined by the statistical accuracy. 2172400800018 (1 sigma confidence level). 2172400800019 STATUS (TABLE) Table II from 82ANTWER,,147 2172400800020 HISTORY (20200803U) SD: STATUS updated. 2172400800021 ENDBIB 19 0 2172400800022 NOCOMMON 0 0 2172400800023 DATA 2 1 2172400800024 DATA-MAX MONIT 2172400800025 MB B 2172400800026 0.370 587.6 2172400800027 ENDDATA 3 0 2172400800028 ENDSUBENT 27 0 2172400899999 ENDENTRY 8 0 2172499999999