ENTRY 30047 20080430 31253004700000001 SUBENT 30047001 20080430 31253004700100001 BIB 12 40 3004700100002 INSTITUTE (3AULAUA) 3004700100003 REFERENCE (J,JNE,22,63,196802) nubar+n-emission parameters 3004700100004 (R,AAEC/TM-385,196706) same as JNE 22,63,6802 3004700100005 (R,AAEC/TM-172,196703) experimental method described 3004700100006 AUTHOR (J.W.Boldeman) 3004700100007 TITLE Prompt nubar measurements for the spontaneous fission 3004700100008 of Pu240 and Pu242 3004700100009 EXP-YEAR (1966) 3004700100010 METHOD Gadolinium bath in coincidence with pulses from fission3004700100011 counter. Fission neutrons recorded for 40 microsec and 3004700100012 stored in temporary store. After 100 microsec. waiting 3004700100013 period background recorded for another 40 microsec. At 3004700100014 end of entire counting cycle contents of temporary 3004700100015 store transferred to multiple event counter provided 3004700100016 second detectable fission event had not occurred. If so3004700100017 contents of temporary store were erased. 3004700100018 DETECTOR (STANK) liquid scintillator tank 76 cm in diameter, 3004700100019 containing 240 litres of gadolinium loaded Ne323,viewed3004700100020 by 12 photomultipliers connected in 3 coincident banks 3004700100021 of four.Environmental background reduced by 3 feet of 3004700100022 heavy concrete. 3004700100023 (FISCH) fast ionisation chamber to record fissions, 3004700100024 with high detection efficiency(97.5% for Pu240 and 3004700100025 Pu242, 98% for Cf252),high discrimination against 3004700100026 amplifier noise and complete freedom from alpha pile-up3004700100027 effects 3004700100028 ANALYSIS Nubar value deduced from emission probabilities after 3004700100029 correcting for dead time and background counts and 3004700100030 taking detection efficiency into consideration 3004700100031 MONITOR (98-CF-252(0,F),PR,NU) 3004700100032 assumed value is weighted mean of 3004700100033 measurements of Asplund-Nilsson et al (NSE 16 124 1963)3004700100034 and Hopkins et al (NP 48 433 1963) 3004700100035 PART-DET (N) prompt neutrons 3004700100036 STATUS data taken from JNE 22 63 6802 3004700100037 (SPSDD,30367001) data superseded by exfor 30367. 3004700100038 HISTORY (19670329R) data received from Symonds on punched cards3004700100039 (19670418C) data compiled into Dastar 3004700100040 (19770117A) '(spsdd)' added. 3004700100041 (20080428A) BIB section updated 3004700100042 ENDBIB 40 0 3004700100043 COMMON 2 3 3004700100044 MONIT MONIT-ERR 3004700100045 NO-DIM NO-DIM 3004700100046 3.7840E+00 0.0000E+00 3004700100047 ENDCOMMON 3 0 3004700100048 ENDSUBENT 47 0 3004700199999 SUBENT 30047002 20080430 31253004700200001 BIB 7 27 3004700200002 REACTION (94-PU-240(0,F),PR,NU) 3004700200003 SAMPLE total weight 800 millig. Percent isotopic composition 3004700200004 Pu239(24.46),Pu240(74.14),Pu241(1.29),Pu242(0.10) and 3004700200005 Am241(0.18) 3004700200006 COMMENT determined also neutron emission probabilities 3004700200007 second moment of nu about origin= 6.023+-0.035 3004700200008 second moment about nubar =1.150+-0.004 3004700200009 shape dependent parameter r=0.820+-0.002 3004700200010 neutrons emitted probabilities 3004700200011 0 0.0639+-0.010 3004700200012 1 0.2284+-0.0021 3004700200013 2 0.3299+-0.0022 3004700200014 3 0.2536+-0.0028 3004700200015 4 0.1047+-0.0031 3004700200016 5 0.0166+-0.0015 3004700200017 6 0.0030+-0.0005 3004700200018 errors reported were assessed from experimental repro- 3004700200019 ducibility 3004700200020 STATUS (SPSDD,30367003) superseded by exfor 30367.003. 3004700200021 HISTORY (19701126T) data transformed from dastar-00144 3004700200022 CORRECTION percentage correction applied to experimental values, 3004700200023 false gates= 0.02,Fission spectra differences=-0.66 and3004700200024 dead time=-0.40.Impurity correction negligible 3004700200025 ERR-ANALYS the percentage contribution to nubar accuracy was, 3004700200026 statistical accuracy=0.16,False gates=0.005,Fission 3004700200027 spectra differences=0.33,Dead time=0.08 and delayed 3004700200028 gammas=0.10. Standard error not included 3004700200029 ENDBIB 27 0 3004700200030 NOCOMMON 0 0 3004700200031 NODATA 0 0 3004700200032 ENDSUBENT 31 0 3004700299999 SUBENT 30047003 20080430 31253004700300001 BIB 7 26 3004700300002 REACTION (94-PU-242(0,F),PR,NU) 3004700300003 SAMPLE total weight 600 millig. Percent isotopic composition 3004700300004 Pu239(0.017),Pu240(0.039),Pu241(0.064) and Pu242(99.88)3004700300005 COMMENT determined also neutron emission probabilities 3004700300006 second moment of nu about origin =5.981+-0.036 3004700300007 second moment about nubar =1.153+-0.004 3004700300008 shape dependent parameter r=0.822+-0.002 3004700300009 neutrons emitted probabilities 3004700300010 0 0.0648+-0.011 3004700300011 1 0.2296+-0.0021 3004700300012 2 0.3362+-0.0024 3004700300013 3 0.2470+-0.0027 3004700300014 4 0.1019+-0.0032 3004700300015 5 0.0163+-0.0015 3004700300016 6 0.0030+-0.0006 3004700300017 errors reported were assessed from experimental repro- 3004700300018 ducibility 3004700300019 STATUS (SPSDD,30367004) superseded by exfor 30367.004. 3004700300020 HISTORY (19701126T) transformed from Dastar-00145 3004700300021 CORRECTION percentage correction applied to experimental values, 3004700300022 false gates= 0.02,Fission spectra differences=-0.67 and3004700300023 dead time=-0.40. Impurity correction negligible 3004700300024 ERR-ANALYS percentage contributions to nubar accuracy were- 3004700300025 statistical accuracy=0.17,False gates=0.005, Fission 3004700300026 spectra differences=0.33,Dead time=0.08 and delayed 3004700300027 gammas=0.10 3004700300028 ENDBIB 26 0 3004700300029 NOCOMMON 0 0 3004700300030 NODATA 0 0 3004700300031 ENDSUBENT 30 0 3004700399999 ENDENTRY 3 0 3004799999999