ENTRY 23354 20201211 22962335400000001 SUBENT 23354001 20201211 22962335400100001 BIB 16 54 2335400100002 TITLE Delayed neutron precursors-IV: 87Se,88Se and 89Se; 2335400100003 half-lives, neutron emission probabilities and fission 2335400100004 yields 2335400100005 AUTHOR (L.Tomlinson, M.H.Hurdus) 2335400100006 REFERENCE (J,JIN,33,3609,1971) 2335400100007 INSTITUTE (2UK HAR) AERE,Harwell,Didcot,Berkshire 2335400100008 REL-REF (M,,L.Tomlinson+,J,RCA,12,182,1969) 2335400100009 Method base on isotopic exchange with H(2)Se gas. 2335400100010 (I,,L.Tomlinson,J,JIN,28,287,1966) 2335400100011 (I,23351001,L.Tomlinson+,J,JIN,30,1125,1968) 2335400100012 Neutron counting system 2335400100013 (R,,P.del Marmol,J,ND/A,6,141,1969) 2335400100014 HL and Pn for Br isotopes, 2335400100015 excluding Pn for Br-87 - it's average of two measured 2335400100016 values from: 2335400100017 (R,41617001,P.M.Aron+,J,SJA,16,447,1964) 2335400100018 Engl.translation of: 2335400100019 (R,41617001,P.M.Aron+,J,AE,16,368,1964) 2335400100020 (R,23356002,P.del Marmol+,J,RCA,16,4,1971) 2335400100021 FACILITY (REAC,2UK HAR) LIDO reactor. 2335400100022 INC-SOURCE (REAC) 2335400100023 INC-SPECT Thermal neutrons. 2335400100024 METHOD (CHSEP) Rapid radiochemical method based on isotopic 2335400100025 exchange with H(2)Se gas. 2335400100026 Chemical yields were determined by Se-75 tracer. 2335400100027 -Preliminary experiments were carried out in the 2335400100028 absence of radiation to study the effects of Se and U 2335400100029 concentration, reducing agent and reaction time on the 2335400100030 chemical yield of Se. 2335400100031 - 12 sec irradiation. 2335400100032 - Blank experiments to measure Rb-93 contribution 2335400100033 ( < 5%); 2335400100034 Kr-93 HL was found to be 1.3 sec. 2335400100035 DETECTOR See REL-REFs. 2335400100036 Neutron detection efficiency 1.62%, calibration by 2335400100037 241Am/Li standard source (average neutron energy 2335400100038 ~0.6 MeV). 2335400100039 SAMPLE In exchange vessel: 2.0 ml of 0.5N HCl solution, 2335400100040 containing 200 mg 93% U-235 as uranil chloride, 2335400100041 22 ug Se as selenite, 0.5 ug each KI and KBr, 2335400100042 reducing agent ( typically 0.7 mg K2S2O5 ). 2335400100043 MONITOR (92-U-235(N,F)56-BA-140,CUM,FY) 2335400100044 Neutron flux was measured by separating Ba-140. 2335400100045 Cobalt wires were also used as an additional check on 2335400100046 the neutron flux. 2335400100047 DECAY-DATA (35-BR-87,55.65SEC) 55.65+-0.20 sec 2335400100048 (35-BR-88,15.85SEC) 15.85+-0.10 sec 2335400100049 (35-BR-89,4.45SEC) 4.45+-0.30 sec 2335400100050 ASSUMED (ASSUM1,35-BR-87(0,B-)36-KR-87,,PN) 2335400100051 (ASSUM2,35-BR-88(0,B-)36-KR-88,,PN) 2335400100052 (ASSUM3,35-BR-89(0,B-)36-KR-89,,PN) 2335400100053 CORRECTION Rb-93 contribution was subtracted. 2335400100054 HISTORY (20171031C) M.M. 2335400100055 (20201211U) SD: Correction in Subents 005-007. 2335400100056 ENDBIB 54 0 2335400100057 COMMON 6 3 2335400100058 ASSUM1 ASSUM1-ERR ASSUM2 ASSUM2-ERR ASSUM3 ASSUM3-ERR 2335400100059 NO-DIM NO-DIM NO-DIM NO-DIM NO-DIM NO-DIM 2335400100060 0.023 0.004 0.047 0.004 0.088 0.009 2335400100061 ENDCOMMON 3 0 2335400100062 ENDSUBENT 61 0 2335400199999 SUBENT 23354002 20171031 22682335400200001 BIB 8 24 2335400200002 REACTION (34-SE-87(0,B-)35-BR-87,,PN) 2335400200003 DECAY-DATA (34-SE-87,5.41SEC) 5.41+-0.10 sec measured HL 2335400200004 METHOD Chemistry time 2.3 sec 2335400200005 ADD-RES (DECAY) Se-87 HL value 5.43+0.10(includes systematic 2335400200006 error) sec was defined as weighted average of two 2335400200007 measurements at various irradiation times: 2335400200008 12 sec 5.43+-0.04 sec 2335400200009 3 sec 5.29+-0.10 sec 2335400200010 ANALYSIS -Pn was calculated using Se-87 exp. half-life and 2335400200011 known HL and Pn for Br-87 ( see Subent 001, ASSUMED). 2335400200012 The best Pn was defined by the best fit of theoretical 2335400200013 curve to the exp.results. 2335400200014 REL-REF (A,,L.Tomlinson+,C,67VIENNA,,61,1967) 0.9% 2335400200015 Published at 1968 . 2335400200016 (A,,A.C.Wahl+,C,69VIENNA,,813,1969) 2335400200017 Updated version - 1.% 2335400200018 (D,23350003,L.Tomlinson+,J,JIN,30,1995,1968) < 0.8 % 2335400200019 (A,23353004,P.del Marmol+,J,JIN,32,705,1970) 2335400200020 0.23+-0.07 % 2335400200021 (A,22047006,J.-V.Kratz+,J,JIN,32,3713,1970) 2335400200022 0.25+-0.05 % 2335400200023 ERR-ANALYS (DATA-ERR) Type of error is not explained in the 2335400200024 article 2335400200025 STATUS (TABLE) Table 2 of J.Inorg.Nucl.Chem.,33,3609,1971 2335400200026 ENDBIB 24 0 2335400200027 NOCOMMON 0 0 2335400200028 DATA 2 1 2335400200029 DATA DATA-ERR 2335400200030 NO-DIM NO-DIM 2335400200031 0.0016 0.0003 2335400200032 ENDDATA 3 0 2335400200033 ENDSUBENT 32 0 2335400299999 SUBENT 23354003 20171031 22682335400300001 BIB 8 21 2335400300002 REACTION (34-SE-88(0,B-)35-BR-88,,PN) 2335400300003 DECAY-DATA (34-SE-88,1.53SEC) 1.53+-0.06 sec measured HL 2335400300004 METHOD Chemistry time 2.3 sec 2335400300005 ADD-RES (DECAY) Se-88 HL value 1.53+-0.06(includes systematic 2335400300006 error) sec was defined as weighted average of two 2335400300007 measurements at various irradiation times: 2335400300008 12 sec 1.46+-0.06 sec 2335400300009 3 sec 1.57+-0.04 sec 2335400300010 ANALYSIS Pn was from the shape of Se-88/Br-88 decay curve using 2335400300011 known HL and Pn for Br-88 ( see Subent 001, ASSUMED). 2335400300012 The best Pn was defined by the best fit of theoretical 2335400300013 curve to the exp.results. 2335400300014 REL-REF (D,,L.Tomlinson+,C,67VIENNA,,61,1967) 2.2% 2335400300015 (D,,A.C.Wahl+,C,69VIENNA,,813,1969) 2335400300016 Updated version - 3.% 2335400300017 (A,23353001,P.del Marmol+,J,JIN,32,705,1970) < 1.% 2335400300018 (D,22047007,J.-V.Kratz+,J,JIN,32,3713,1970) 2335400300019 0.15+-0.09 % 2335400300020 ERR-ANALYS (DATA-ERR) Type of error is not explained in the 2335400300021 article 2335400300022 STATUS (TABLE) Table 2 of J.Inorg.Nucl.Chem.,33,3609,1971 2335400300023 ENDBIB 21 0 2335400300024 NOCOMMON 0 0 2335400300025 DATA 2 1 2335400300026 DATA DATA-ERR 2335400300027 NO-DIM NO-DIM 2335400300028 0.0075 0.0006 2335400300029 ENDDATA 3 0 2335400300030 ENDSUBENT 29 0 2335400399999 SUBENT 23354004 20171031 22682335400400001 BIB 8 16 2335400400002 REACTION (34-SE-89(0,B-)35-BR-88,,PN) 2335400400003 DECAY-DATA (34-SE-89,0.41SEC) 0.41+-0.04 sec measured HL 2335400400004 METHOD Chemistry time 1.0 sec. 2335400400005 ADD-RES (DECAY) Se-89 HL value 0.41+-0.04(includes systematic 2335400400006 error) sec was defined at measurement of 0.5 sec 2335400400007 irradiation time. 2335400400008 ANALYSIS Pn was from the shape of Se-89/Br-89 decay curve using 2335400400009 known HL and Pn for Br-89 ( see Subent 001, ASSUMED). 2335400400010 The best Pn was defined by the best fit of theoretical 2335400400011 curve to the exp.results. 2335400400012 REL-REF (A,,L.Tomlinson+,C,67VIENNA,,61,1967) 5.% 2335400400013 (A,,A.C.Wahl+,C,69VIENNA,,813,1969) 2335400400014 Updated version - 7.% 2335400400015 ERR-ANALYS (DATA-ERR) Type of error is not explained in the 2335400400016 article 2335400400017 STATUS (TABLE) Table 2 of J.Inorg.Nucl.Chem.,33,3609,1971 2335400400018 ENDBIB 16 0 2335400400019 NOCOMMON 0 0 2335400400020 DATA 2 1 2335400400021 DATA DATA-ERR 2335400400022 NO-DIM NO-DIM 2335400400023 0.050 0.015 2335400400024 ENDDATA 3 0 2335400400025 ENDSUBENT 24 0 2335400499999 SUBENT 23354005 20201211 22962335400500001 BIB 5 12 2335400500002 REACTION (92-U-235(N,F)ELEM/MASS,CUM,FY,,SPA) 2335400500003 DECAY-DATA (34-SE-87,5.41SEC,DN,,0.0016) 5.41+-0.10 sec 2335400500004 (34-SE-88,1.53SEC,DN,,0.075) 1.53+-0.06 sec 2335400500005 (34-SE-89,0.41SEC,DN,,0.050) 0.41+-0.04 sec 2335400500006 Measured HLs and Pn ( see Subents 002-004) 2335400500007 FLAG (1.) Irradiation time 12 sec 2335400500008 (2.) Irradiation time 3 sec 2335400500009 (3.) Irradiation time 0.5 sec 2335400500010 STATUS (TABLE) Table 3 of J.Inorg.Nucl.Chem.,33,3609,1971; 2335400500011 (SPSDD,23354007) Average values are in Subent 007. 2335400500012 HISTORY (20201211U) SD: DECAY-DATA corrected (missed comma 2335400500013 before intensity added). 2335400500014 ENDBIB 12 0 2335400500015 COMMON 1 3 2335400500016 EN-DUMMY 2335400500017 EV 2335400500018 0.0253 2335400500019 ENDCOMMON 3 0 2335400500020 DATA 4 7 2335400500021 ELEMENT MASS DATA FLAG 2335400500022 NO-DIM NO-DIM PC/FIS NO-DIM 2335400500023 34. 87. 0.71 1. 2335400500024 34. 87. 0.57 2. 2335400500025 34. 87. 0.71 3. 2335400500026 34. 88. 0.41 1. 2335400500027 34. 88. 0.36 2. 2335400500028 34. 88. 0.41 3. 2335400500029 34. 89. 0.11 3. 2335400500030 ENDDATA 9 0 2335400500031 ENDSUBENT 30 0 2335400599999 SUBENT 23354006 20201211 22962335400600001 BIB 6 15 2335400600002 REACTION (92-U-235(N,F)ELEM/MASS,DL/CUM,NU,,SPA) 2335400600003 Delayed neutron yields for specific precursors 2335400600004 DECAY-DATA (34-SE-87,5.41SEC,DN,,0.0016) 5.41+-0.10 sec 2335400600005 (34-SE-88,1.53SEC,DN,,0.075) 1.53+-0.06 sec 2335400600006 (34-SE-89,0.41SEC,DN,,0.050) 0.41+-0.04 sec 2335400600007 Measured HLs and Pn ( see Subents 002-004) 2335400600008 ANALYSIS Cumulative fission yield multiplied by Pn 2335400600009 ERR-ANALYS (DATA-ERR) Standard deviation 2335400600010 STATUS (TABLE) Table 3 of J.Inorg.Nucl.Chem.,33,3609,1971. 2335400600011 (DEP,23354002) Pn(87Se) 2335400600012 (DEP,23354003) Pn(88Se) 2335400600013 (DEP,23354004) Pn(89Se) 2335400600014 (DEP,23354005) Cumulative fission yields 2335400600015 HISTORY (20201211U) SD: DECAY-DATA corrected (missed comma 2335400600016 before intensity added). 2335400600017 ENDBIB 15 0 2335400600018 COMMON 1 3 2335400600019 EN-DUMMY 2335400600020 EV 2335400600021 0.0253 2335400600022 ENDCOMMON 3 0 2335400600023 DATA 4 3 2335400600024 ELEMENT MASS DATA DATA-ERR 2335400600025 NO-DIM NO-DIM PC/FIS PC/FIS 2335400600026 34. 87. 0.11E-2 0.03E-2 2335400600027 34. 88. 0.29E-2 0.04E-2 2335400600028 34. 89. 0.55E-2 0.25E-2 2335400600029 ENDDATA 5 0 2335400600030 ENDSUBENT 29 0 2335400699999 SUBENT 23354007 20201211 22962335400700001 BIB 7 24 2335400700002 REACTION (92-U-235(N,F)ELEM/MASS,CUM,FY,,SPA) 2335400700003 ANALYSIS Average of directly measured data ( Subent 005) 2335400700004 DECAY-DATA (34-SE-87,5.41SEC,DN,,0.0016) 5.41+-0.10 sec 2335400700005 (34-SE-88,1.53SEC,DN,,0.075) 1.53+-0.06 sec 2335400700006 (34-SE-89,0.41SEC,DN,,0.050) 0.41+-0.04 sec 2335400700007 Measured HLs and Pn ( see Subents 002-004) 2335400700008 REL-REF (A,,A.C.Wahl+,C,69VIENNA,,813,1969)Reasonable agreement2335400700009 Se-87 0.69%, Se-88 - 0.32% , Se-89 - 0.10% . 2335400700010 (D,23350002,L.Tomlinson+,J,JIN,30,1995,1968) 2335400700011 1.17+-0.25% for Se-87 2335400700012 Value of this experiment is more accurate and reliable2335400700013 than authors earlier value - see explanation of authors2335400700014 page 3620 of JIN,33,3609,1971. 2335400700015 (A,23353002,P.del Marmol+,J,JIN,32,705,1970) 2335400700016 0.65+-0.13% for Se-87 2335400700017 (A,22047003,J.-V.Kratz+,J,JIN,32,3713,1970) 2335400700018 0.97+-0.16% for Se-87; 0.86+-0.20% for Se-88 2335400700019 ERR-ANALYS (DATA-ERR) Standard deviation 2335400700020 STATUS (TABLE) Tables 3,4 of J.Inorg.Nucl.Chem.,33,3609,1971;2335400700021 text of abstract, page 3609 of 2335400700022 J.Inorg.Nucl.Chem.,33,3609,1971. 2335400700023 (DEP,23354005) Directly measured data 2335400700024 HISTORY (20201211U) SD: DECAY-DATA corrected (missed comma 2335400700025 before intensity added). 2335400700026 ENDBIB 24 0 2335400700027 COMMON 1 3 2335400700028 EN-DUMMY 2335400700029 EV 2335400700030 0.0253 2335400700031 ENDCOMMON 3 0 2335400700032 DATA 4 3 2335400700033 ELEMENT MASS DATA DATA-ERR 2335400700034 NO-DIM NO-DIM PC/FIS PC/FIS 2335400700035 34. 87. 0.66 0.13 2335400700036 34. 88. 0.39 0.05 2335400700037 34. 89. 0.11 0.04 2335400700038 ENDDATA 5 0 2335400700039 ENDSUBENT 38 0 2335400799999 ENDENTRY 7 0 2335499999999