ENTRY 23108 20130203 22342310800000001 SUBENT 23108001 20130203 22342310800100001 BIB 14 40 2310800100002 TITLE The thermal neutron capture cross-section of Np-237 2310800100003 AUTHOR (F.Brown, G.R.Hall) 2310800100004 INSTITUTE (2UK HAR) 2310800100005 REFERENCE (J,JIN,2,205,1956) 2310800100006 FACILITY (REAC,2UK HAR) BEPO pile. 2310800100007 INC-SPECT Thermal neutrons. 2310800100008 INC-SOURCE (REAC) 2310800100009 METHOD (CADMB) Contribution from epi-Cd region (>0.4eV) 2310800100010 neutrons was obtained by irradiating foils and flux 2310800100011 monitors inside Cd boxes. 2310800100012 (ACTIV) Foils of Np-237 and Au-198 monitor gold wires 2310800100013 or foils were irradiated in BEPO at least 20 days. 2310800100014 (ASPEC) Alpha-pulse-height analysis. 2310800100015 (CHSEP) Activity of gold was obtained by dissolving the2310800100016 metal in acid, diluting and counting aliquots. 2310800100017 (STTA) Sandwich targets irradiation. 2310800100018 DECAY-DATA (93-NP-237,2.20E+6YR) HL=(2.20+-0.04)*10**6 years. 2310800100019 (93-NP-238,2.1D) 2310800100020 (94-PU-238,89.6YR,A,5490.) HL=89.6+-0.4 years. 2310800100021 DETECTOR (D4PI) 4-pi-type proportional methane flow beta-counter2310800100022 to measure gold activity. 2310800100023 (IOCH) Gridded ionization chamber to measure Np foils 2310800100024 activity. 2310800100025 SAMPLE Eight Np-237 samples on thin Al disks, contamination 2310800100026 of about 1% of alpha-activity from Pu-239 and Am-241. 2310800100027 Au flux monitors : weighed wire of 0.127 mm diameter 2310800100028 or weighed foils of thickness 0.0052 mm, 10 mg/cm**2. 2310800100029 Assembly was wrapped in Al foil of thickness 0.007 mm,2310800100030 1.8 mg/cm**2 . 2310800100031 For Cd run - Cd boxes of wall-thickness about 0.1 cm. 2310800100032 ANALYSIS Reaction chain analysis with the help of ROOT MERCS 2310800100033 CORRECTION For self-shielding for neutrons for gold wire - 4.6 %.2310800100034 For Am-241 presence in sample before irradiation. 2310800100035 For dead-time, in observe counting-rates. 2310800100036 For loss of beta-counts in 250-microg/cm**2 Al films -2310800100037 1% . 2310800100038 For self-absorption of samples - 0.5+-0.5 % . 2310800100039 HISTORY (20100511C) M.M. 2310800100040 (20130203U) SD: Title of the journal in ref. was 2310800100041 corrected (INC -> JIN). 2310800100042 ENDBIB 40 0 2310800100043 NOCOMMON 0 0 2310800100044 ENDSUBENT 43 0 2310800199999 SUBENT 23108002 20100511 22212310800200001 BIB 7 22 2310800200002 REACTION (93-NP-237(N,G)93-NP-238,,SIG,,MXW) 2310800200003 MONIT-REF (,,R,AECU-2040,(2),195306) 2310800200004 A.E.C.U. 2040, supl.2, 1953. 2310800200005 MONITOR (79-AU-197(N,G)79-AU-198,,SIG,,MXW) 2310800200006 DECAY-MON (79-AU-198,2.70D) Neutron flux was measured by gold 2310800200007 wires or foils in close proximity. 2310800200008 MISC-COL (MISC) Ratio of epi-Cd to sub-Cd contributions. 2310800200009 ERR-ANALYS Errors due to known causes: 2310800200010 Flux: 2310800200011 (ERR-1) Weight of gold. 2310800200012 (ERR-2) Deviation between beta sources. 2310800200013 (ERR-3) Film-absorption correction. 2310800200014 (ERR-4) Self-absorption correction. 2310800200015 Beta-counting statistics, irradiation time, Au-198 2310800200016 half-life errors are negligible. 2310800200017 Pu-238/Np-237 ratio: 2310800200018 (ERR-5) HL of Np-237. 2310800200019 (ERR-6) HL of Pu-238. 2310800200020 (ERR-7) Statistics in alpha-pulse analysis. 2310800200021 (ERR-S) Total random error . 2310800200022 (ERR-SYS) Total systematic error . 2310800200023 STATUS (TABLE) Table 1 of J,INC,2,205,1956. 2310800200024 ENDBIB 22 0 2310800200025 COMMON 12 6 2310800200026 EN-DUMMY MONIT MONIT-ERR ERR-1 ERR-2 ERR-3 2310800200027 ERR-4 ERR-5 ERR-6 ERR-7 ERR-S ERR-SYS 2310800200028 EV B PER-CENT PER-CENT PER-CENT PER-CENT 2310800200029 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 2310800200030 0.0253 98. 1. 0.5 0.5 0.5 2310800200031 0.5 2. 0.5 1.5 1.7 2.4 2310800200032 ENDCOMMON 6 0 2310800200033 DATA 2 4 2310800200034 DATA MISC 2310800200035 B NO-DIM 2310800200036 171. 0.27 2310800200037 175. 0.23 2310800200038 163. 0.25 2310800200039 177. 0.22 2310800200040 ENDDATA 6 0 2310800200041 ENDSUBENT 40 0 2310800299999 SUBENT 23108003 20100511 22212310800300001 BIB 3 5 2310800300002 REACTION (93-NP-237(N,G)93-NP-238,,SIG,,MXW) 2310800300003 ERR-ANALYS (ERR-S) Total random error (=6b). 2310800300004 (ERR-T) Total error (=4.2%). 2310800300005 STATUS (TABLE) Table 1 of J,INC,2,205,1956. 2310800300006 (DEP,23108002) Average of set of four runs. 2310800300007 ENDBIB 5 0 2310800300008 NOCOMMON 0 0 2310800300009 DATA 4 1 2310800300010 EN-DUMMY DATA ERR-T ERR-S 2310800300011 EV B B PER-CENT 2310800300012 0.0253 172. 7. 3.5 2310800300013 ENDDATA 3 0 2310800300014 ENDSUBENT 13 0 2310800399999 ENDENTRY 3 0 2310899999999