ENTRY 13913 20240314 15071391300000001
SUBENT 13913001 20240314 15071391300100001
BIB 10 21 1391300100002
AUTHOR (J.A.Grundl) 1391300100003
TITLE Measurement of the Average Fission Cross-Section 1391300100004
Ratio, sigmaF(235U)/sigmaF(238U) for 235U and 239Pu 1391300100005
Fission Neutrons 1391300100006
REFERENCE (C,71VIENNA,,107,1971) 1391300100007
REL-REF (N,10304001,J.A.Grundl+,J,ANS,15,945,1972) 1391300100008
Measurements with 252Cf neutron source. 1391300100009
INSTITUTE (1USANBS) 1391300100010
FACILITY (REAC,1USANBS) 1391300100011
SAMPLE (92-U-235,ENR=0.997) Two foils: Enriched and natural 1391300100012
uranium, 200 microg/cm2 thick. 1391300100013
DETECTOR (IOCH) 1391300100014
MONITOR (92-U-235(N,F),,SIG) Run to run thermal neutron flux 1391300100015
levels in the cavity were monitored with a commercial 1391300100016
235U fission chamber exposed to a beam taken of the 1391300100017
front face of the thermal column. A triple scaler 1391300100018
arrangement was also used to record pulses from this 1391300100019
monitor chamber. 1391300100020
HISTORY (20140804C) BP 1391300100021
(20230604A) OS. Uncertainties modified in subs.2,3 1391300100022
(20240314A) On. Major alterations in 002. 1391300100023
ENDBIB 21 0 1391300100024
NOCOMMON 0 0 1391300100025
ENDSUBENT 24 0 1391300199999
SUBENT 13913002 20240314 15071391300200001
BIB 7 20 1391300200002
REACTION ((92-U-235(N,F),,SIG,,FIS)/(92-U-238(N,F),,SIG,,FIS)) 1391300200003
STATUS (TABLE,,J.A.Grundl,C,71VIENNA,,107,1971) page 108. 1391300200004
METHOD (PHD) 1391300200005
INC-SOURCE Fission rates were observed with 235U fission 1391300200006
neutrons source. 1391300200007
INC-SPECT Energy of 235U fission neutrons is not listed in the 1391300200008
article. We can assume average fission neutrons 1391300200009
energy of ~2 MeV. 1391300200010
ERR-ANALYS (ERR-T) Uncertainties are due to: 1391300200011
(ERR-S) counting statistics - 0.3%. 1391300200012
(ERR-1) thermal column monitor stability - 0.6%. 1391300200013
(ERR-2) source-detector position - 2%. 1391300200014
(ERR-3) cavity position - 1.2%. 1391300200015
(ERR-4) reactor background - 2%. 1391300200016
(ERR-5) cavity return background - 2.5%. 1391300200017
(ERR-6) relative detector efficiency - 0.3%. 1391300200018
(ERR-7) intrinsic source-detector scattering - 1.5%. 1391300200019
(ERR-8) foil weight ratio - 2%. 1391300200020
HISTORY (20230604A) ERR-T in DATA section deleted 1391300200021
(20240314A) On. EN-DUMMY=2.0 MeV -> KT-DUMMY=1.32 MeV 1391300200022
ENDBIB 20 0 1391300200023
COMMON 10 6 1391300200024
ERR-T ERR-S ERR-1 ERR-2 ERR-3 ERR-4 1391300200025
ERR-5 ERR-6 ERR-7 ERR-8 1391300200026
PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 1391300200027
PER-CENT PER-CENT PER-CENT PER-CENT 1391300200028
4.7 0.3 0.6 2.0 1.2 2.01391300200029
2.5 0.3 1.5 2.0 1391300200030
ENDCOMMON 6 0 1391300200031
DATA 2 1 1391300200032
KT-DUMMY DATA 1391300200033
MEV NO-DIM 1391300200034
1.32 3.71 1391300200035
ENDDATA 3 0 1391300200036
ENDSUBENT 35 0 1391300299999
SUBENT 13913003 20230707 15071391300300001
BIB 8 23 1391300300002
REACTION (((92-U-235(N,F),,SIG,,FIS)/ 1391300300003
(92-U-238(N,F),,SIG,,FIS))// 1391300300004
((92-U-235(N,F),,SIG,,FIS)/(92-U-238(N,F),,SIG,,FIS))) 1391300300005
STATUS (TABLE,,J.A.Grundl,C,71VIENNA,,107,1971) page 108. 1391300300006
METHOD (PHD) 1391300300007
INC-SOURCE Fission rates were observed with 235U (denominator 1391300300008
ratio) and 239Pu (nominator ratio) fission neutron 1391300300009
sources. 1391300300010
INC-SPECT Energies of 235U and 239Pu fission neutrons are not 1391300300011
listed in the article. We can assume that 235U and 1391300300012
239Pu average fission neutrons energies are ~2 and 1391300300013
~2.1 MeV, respectively. 1391300300014
COMMENT From the knowledge of 235U fission source ratio of 1391300300015
3.71 and 239Pu/235U sources ratio of 9.70, one may 1391300300016
reconstruct a fission cross section ratio for a pure 1391300300017
239Pu source as 3.5987 +- 0.1704. 1391300300018
ERR-ANALYS (ERR-T) Uncertainties are due to: 1391300300019
(ERR-S) counting statistics - 0.4%. 1391300300020
(ERR-1) thermal column monitor stability - 0.6%. 1391300300021
(ERR-2) source-detector position - 0.7%. 1391300300022
(ERR-3) cavity position - 0.5%. 1391300300023
(ERR-4) reactor background - 0.6%. 1391300300024
HISTORY (20230604A) ERR-T in DATA section deleted 1391300300025
ENDBIB 23 0 1391300300026
COMMON 6 3 1391300300027
ERR-T ERR-S ERR-1 ERR-2 ERR-3 ERR-4 1391300300028
PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT 1391300300029
1.3 0.4 0.6 0.7 0.5 0.61391300300030
ENDCOMMON 3 0 1391300300031
DATA 3 1 1391300300032
EN-DUM-NM EN-DUM-DN DATA 1391300300033
MEV MEV NO-DIM 1391300300034
2.1 2.0 0.970 1391300300035
ENDDATA 3 0 1391300300036
ENDSUBENT 35 0 1391300399999
ENDENTRY 3 0 1391399999999