ENTRY 10930 20250629 152110930000 1 SUBENT 10930001 20250629 152110930001 1 BIB 10 35 10930001 2 TITLE Prompt Neutron Multiplicity Distribution in the 10930001 3 Spontaneous Fission of Curium-242 10930001 4 AUTHOR (J.Halperin,C.E.Bemis JR,J.W.T.Dabbs,B.H.Ketelle, 10930001 5 R.W.Stoughton,R.W.Hoff,R.J.Dougan) 10930001 6 REFERENCE (J,NSE,75,56,1980) 10930001 7 #doi:10.13182/NSE80-A20317 10930001 8 (J,BAP,25,487(AG9),1980) 10930001 9 INSTITUTE (1USAORL,1USALRL) 10930001 10 DETECTOR (PROPC) Fission neutrons counted with 30 helium-3 10930001 11 detectors, 2.5-cm diameter, 60-cm long, 6-atm 10930001 12 pressure, embedded in a cylindrical paraffin and 10930001 13 polyethylene matrix, 54-cm diameter, 90-cm long. 10930001 14 (FISCH) Gas filled counter with hemispherical 10930001 15 geometry. Active sample deposited on convex surface, 10930001 16 electron charge collected on concentric surface 2-mm 10930001 17 from source. 10930001 18 METHOD (COINC) Fission chamber inserted into a 10-cm 10930001 19 diameter hole that penetrates central core of 10930001 20 paraffin-polyethylene cylinder. Helium-3 counters 10930001 21 placed parallel to cylinder axis, spaced symmetrically 10930001 22 into 3 concentric rings. Fission of known Cf-252 10930001 23 sample used to calibrate He-3 counters. A pulse from 10930001 24 a fission chamber serves to open a gate to count 10930001 25 nearly all neutrons detected in coincidence with the 10930001 26 fission fragment. 10930001 27 MONITOR (98-CF-252(0,F),PR,NU) 10930001 28 CORRECTION Corrections made for background neutrons and 10930001 29 accidentals. Contributions to spontaneous fission 10930001 30 rates by impurities not corrected for. 10930001 31 STATUS (APRVD) Approved by J.Halperin, 1981/2/12. 10930001 32 HISTORY (19801201C) 10930001 33 (20170822A) BP: Updated to new date formats,lower 10930001 34 case. Corrections according last EXFOR rules and 10930001 35 Dict. Added fission neutron multiplicity distribution. 10930001 36 (20250624U) OS. 2nd reference corrected 10930001 37 ENDBIB 35 0 10930001 38 COMMON 1 3 10930001 39 MONIT 10930001 40 PRT/FIS 10930001 41 3.760 10930001 42 ENDCOMMON 3 0 10930001 43 ENDSUBENT 42 0 1093000199999 SUBENT 10930002 20170822 143310930 2 1 BIB 6 9 10930 2 2 REACTION (96-CM-242(0,F),PR,NU) 10930 2 3 SAMPLE Cm-242 formed from the radioactive decay of Am-242. 10930 2 4 ERR-ANALYS (DATA-ERR) Quoted error includes counting statistics 10930 2 5 and systematic uncertainties. 10930 2 6 DECAY-DATA (95-AM-242-G,16.02HR,B-) 10930 2 7 (96-CM-242,162.8D,A) 10930 2 8 STATUS (TABLE) page 59. 10930 2 9 HISTORY (19820108A) Corrected reaction, monitor. 10930 2 10 (20170822A) BP: Corrected units. 10930 2 11 ENDBIB 9 0 10930 2 12 NOCOMMON 0 0 10930 2 13 DATA 2 1 10930 2 14 DATA DATA-ERR 10930 2 15 PRT/FIS PRT/FIS 10930 2 16 2.532 0.013 10930 2 17 ENDDATA 3 0 10930 2 18 ENDSUBENT 17 0 10930 299999 SUBENT 10930003 20170822 143310930 3 1 BIB 7 8 10930 3 2 REACTION (96-CM-242(0,F),PR/NUM,NU) 10930 3 3 SAMPLE Cm-242 formed from the radioactive decay of Am-242. 10930 3 4 ERR-ANALYS (ERR-S) Counting statistics only. 10930 3 5 FLAG (1.) Multiplicity 7 is used for 7 and more neutrons. 10930 3 6 DECAY-DATA (95-AM-242-G,16.02HR,B-) 10930 3 7 (96-CM-242,162.8D,A) 10930 3 8 STATUS (TABLE) Table II, page 59. 10930 3 9 HISTORY (20170822C) BP 10930 3 10 ENDBIB 8 0 10930 3 11 NOCOMMON 0 0 10930 3 12 DATA 4 8 10930 3 13 PART-OUT DATA ERR-S FLAG 10930 3 14 NO-DIM NO-DIM NO-DIM NO-DIM 10930 3 15 0. 0.27695 0.00069 10930 3 16 1. 0.41220 0.00084 10930 3 17 2. 0.23595 0.00064 10930 3 18 3. 0.06498 0.00033 10930 3 19 4. 0.008559 0.000115 10930 3 20 5. 0.000549 0.000026 10930 3 21 6. 0.000016 0.000004 10930 3 22 7. 0.0000002 0.0000002 1. 10930 3 23 ENDDATA 10 0 10930 3 24 ENDSUBENT 23 0 10930 399999 SUBENT 10930004 20170822 143310930 4 1 BIB 6 8 10930 4 2 REACTION (98-CF-252(0,F),PR/NUM,NU) 10930 4 3 SAMPLE (98-CF-252,ENR=0.995) Isotopically pure 252Cf was 10930 4 4 deposited with an ion accelerator 400 A beneath the 10930 4 5 surface of an aluminum foil. 10930 4 6 ERR-ANALYS (ERR-S) Counting statistics only. 10930 4 7 FLAG (1.) Multiplicity 7 is used for 7 and more neutrons. 10930 4 8 STATUS (TABLE) Table II, page 59. 10930 4 9 HISTORY (20170822C) BP 10930 4 10 ENDBIB 8 0 10930 4 11 NOCOMMON 0 0 10930 4 12 DATA 4 8 10930 4 13 PART-OUT DATA ERR-S FLAG 10930 4 14 NO-DIM NO-DIM NO-DIM NO-DIM 10930 4 15 0. 0.14366 0.00072 10930 4 16 1. 0.33167 0.00109 10930 4 17 2. 0.31444 0.00107 10930 4 18 3. 0.15708 0.00075 10930 4 19 4. 0.04453 0.00040 10930 4 20 5. 0.00723 0.00015 10930 4 21 6. 0.000644 0.000040 10930 4 22 7. 0.000026 0.000007 1. 10930 4 23 ENDDATA 10 0 10930 4 24 ENDSUBENT 23 0 10930 499999 ENDENTRY 4 0 1093099999999