ENTRY 40922 20180202 41784092200000001 SUBENT 40922001 20180202 41784092200100001 BIB 11 45 4092200100002 INSTITUTE (4RUSRI,4RUSLIN,4KASKAZ) 4092200100003 REFERENCE (J,AE,60,141,1986) Issue 2. 4092200100004 (J,SJA,60,177,1986) Engl.transl.of J,AE,60,141,1986 4092200100005 AUTHOR (B.N.Belyaev,E.A.Gromova,S.S.Kovalenko,A.V.Lovtsyus, 4092200100006 Yu.A.Nemilov,Yu.A.Selitskii,A.V.Stepanov,A.M.Fridkin, 4092200100007 V.B.Funshtein,V.A.Yakovlev,V.N.Okolovich,G.A.Petrov) 4092200100008 TITLE The long-living 236Np isomer's fission cross section 4092200100009 for thermal neutrons 4092200100010 FACILITY 1(REAC,4RUSLIN) Source of neutrons for cross-section 4092200100011 measurements 4092200100012 (CYCLO,4KASKAZ) Cyclotron U-150, proton energy 30 MeV,4092200100013 average current 8. microAmp, used for Np-236 4092200100014 preparation from reaction U-238(p,3n)Np-236-m2 4092200100015 INC-SPECT 1 Horizontal thermal neutron beam with Maxwell 4092200100016 spectrum having temperature 330 deg. Cadmium ratio 4092200100017 on U-235(N,F) is 42.7 +- 2.4 for Cd thickness 1 mm. 4092200100018 Neutron flux 2.E+8 n/cm2/sec . 4092200100019 SAMPLE Np-236 was electrolitically extracted on stainless 4092200100020 steel backing. Sample mass is 36.2 +- 1.3 nanogram 4092200100021 - average of 37.9+-1.5ng (measured by gammas via GeLi)4092200100022 and 35.2+-1.2ng ( measured by mass-spectrometer using 4092200100023 isotopes ratio 4092200100024 Np235/Nm236m/Np237=(0.053+-0.004)/(0.1385+-0.0014)/1. 4092200100025 Np-237 content is 254 +- 8 nanogram. 4092200100026 U-235/U-238/Np-237 mass ratio is 0.011/0.044/1. 4092200100027 Pu-236 admixture is 8.E-5 nanogram 4092200100028 DETECTOR (SOLST) MIca detector for fission cross-section 4092200100029 measurement. 4092200100030 Detection efficiency 96.+-1. % . 4092200100031 (GELI) Ge-Li detector for Np-236 mass measurement 4092200100032 on induced gamma activity using Cd filter. 4092200100033 Detection efficiency 0.0239+-0.0005 in gamma energy 4092200100034 about 160 keV. 4092200100035 METHOD (CADMB) Measurement with and without Cd shield. 4092200100036 CORRECTION For U-235 fission contribution - 1.6%. 4092200100037 Np-235, Np-237, U-238 , Pu-236 contributions were 4092200100038 neglected. 4092200100039 For contribution of Np and U fission by epi-cadmium 4092200100040 neutrons - 0.4 % . 4092200100041 HISTORY (19870624C) Compiled at CJD 4092200100042 (20010315A) Date is corrected 4092200100043 (20180202U) M.M. Upper -> lower case correction. 4092200100044 Ref. SJA,60,177,1986 was added. 4092200100045 Decay data were corrected . 4092200100046 Misprints were corrected. 4092200100047 ENDBIB 45 0 4092200100048 NOCOMMON 0 0 4092200100049 ENDSUBENT 48 0 4092200199999 SUBENT 40922002 20180202 41784092200200001 BIB 9 28 4092200200002 REACTION (93-NP-236(N,F),,SIG,,MXW) 4092200200003 MONITOR (92-U-235(N,F),,SIG) CS at thermal point. 4092200200004 ANALYSIS Westcott factor g=0.9688 at T=330Kelvin was used to 4092200200005 determine U235 fis. CS for thermal spectrum, used for 4092200200006 normalization. 4092200200007 MONIT-REF (,M.Divadeenam+,J,ANE,11,(8),375,1984) 4092200200008 DECAY-DATA (93-NP-236-G,1.55E+05YR,DG,158.3,0.0367, 4092200200009 DG,160.3,0.3138) 4092200200010 3.76+-0.02 % , 32.38+-0.06 % 4092200200011 Used to measure mass of Np-236-G 4092200200012 ERR-ANALYS (ERR-S) Random error of the number-of-fissions ratio 4092200200013 for Np-236 and U-235 4092200200014 (ERR-2) Error of Np-236 nuclei in sample 4092200200015 (ERR-3) Error of U-235 nuclei in sample 4092200200016 (ERR-T) Total error - root mean square 4092200200017 STATUS (TABLE) Table 1 of SJA,60,177,1986 4092200200018 REL-REF (A,,M.H.Studier+,J,PR,97,88,1955) 4092200200019 2800 b at Maxwellian spectrum 4092200200020 (A,,D.Hughes+,R,BNL-325,1958) 4092200200021 2800+-800 b at thermal point 4092200200022 (A,,A.Jaffey,R,ANL-6600,125,1961) 4092200200023 2500+-150 b at Maxwellian spectrum 4092200200024 (A,,C.Lederer+,B,LEDERER-7,,1978) 4092200200025 3000+-600 b at Maxwellian spectrum 4092200200026 (A,,J.E.Gindler+,J,JIN,43,445,1981) 4092200200027 2540+-560 b at reactor spectrum 4092200200028 HISTORY (20010315U) KT changed to EN-MEAN 4092200200029 (20180202A) M.M. ERR-1 -> ERR-S, REL-REFs were added. 4092200200030 ENDBIB 28 0 4092200200031 COMMON 4 3 4092200200032 EN-MEAN EN-NRM MONIT MONIT-ERR 4092200200033 EV EV B B 4092200200034 4.2600E-02 0.0253 582.6 1.1 4092200200035 ENDCOMMON 3 0 4092200200036 DATA 6 1 4092200200037 DATA ERR-T ERR-S ERR-2 ERR-3 ERR-T 4092200200038 B B PER-CENT PER-CENT PER-CENT PER-CENT 4092200200039 2760. 170. 4. 3.5 3. 6. 4092200200040 ENDDATA 3 0 4092200200041 ENDSUBENT 40 0 4092200299999 SUBENT 40922003 20180202 41784092200300001 BIB 6 11 4092200300002 REACTION (93-NP-236-M(N,F),,RI) 4092200300003 MONITOR (92-U-235(N,F),,RI) 4092200300004 From V.M.Gorbschev+, Reaction between Ionizing 4092200300005 Radiations and the Nuclei of Heavy Elements and Fission4092200300006 of the Nuclei, in Russian, Atomizdat, Moscow, 1976. 4092200300007 ASSUMED (ASSUM,93-NP-237(N,F),,SIG) Fission cross-section for 4092200300008 above-cadmium neutrons 4092200300009 CORRECTION Four percent on Np-237 fission of above-cadmium 4092200300010 neutrons and correction on U-235 fission were made 4092200300011 ERR-ANALYS (DATA-ERR) Total error 4092200300012 STATUS (TABLE) Text, page 179 of SJA,60,177,1986 4092200300013 ENDBIB 11 0 4092200300014 COMMON 4 3 4092200300015 EN-MIN MONIT MONIT-ERR ASSUM 4092200300016 EV B B B 4092200300017 0.6 275. 5. 6. 4092200300018 ENDCOMMON 3 0 4092200300019 DATA 2 1 4092200300020 DATA DATA-ERR 4092200300021 B B 4092200300022 1030. 100. 4092200300023 ENDDATA 3 0 4092200300024 ENDSUBENT 23 0 4092200399999 ENDENTRY 3 0 4092299999999