ENTRY 21780 20160907 22522178000000001 SUBENT 21780001 20160907 22522178000100001 BIB 16 73 2178000100002 INSTITUTE (2FR SAC) 2178000100003 REFERENCE (R,CEA-R-2775,196504) 2178000100004 AUTHOR (G.Fraysse,A.Prosdocimi,F.Netter,C.Samour) 2178000100005 TITLE Measurement of the fission cross-section of 235U and 2178000100006 239Pu for thermal neutrons. (in French) 2178000100007 FACILITY (REAC,2FR SAC) Saclay reactor EL-3 2178000100008 INC-SOURCE (REAC) Neutron beam from channel H-2 or H-12 2178000100009 monochromatic by diffraction from a 2178000100010 lead or copper crystal. 2178000100011 SAMPLE Samples of metallic natural boron, U-235 and 2178000100012 Pu-239 on vinyl or aluminum backing. Isotopic 2178000100013 composition measured with a mass spectrometer. 2178000100014 Mass of boron sample measured with an 2178000100015 electrodynamic balance. 2178000100016 METHOD (DIFFR) 2178000100017 Boron and fissile samples aligned along the same 2178000100018 neutron beam from diffraction crystal. 2178000100019 Time integrated neutron flux measured using the 2178000100020 B-10(n,alpha) reaction as standard, and counting 2178000100021 alphas. 2178000100022 Ratio of neutron induced fission events to 2178000100023 spontaneous alpha decay of the fissile sample. 2178000100024 Fission cross section calculated taking into 2178000100025 account the corrections detailed below. 2178000100026 DETECTOR 1(IOCH) 95% argon, 5% carbon dioxide at 580 mmHg 2178000100027 pressure. Used for alphas from B-10(n,alpha) standard.2178000100028 (SCIN) Xenon gas scintillator and 2178000100029 2(SIBAR) surface barrier detector used for fission 2178000100030 fragments and alphas from decay of fissile isotopes. 2178000100031 (SCIN) Li-6 scintill. detector used for neutron flux. 2178000100032 MONITOR (5-B-10(N,A)3-LI-7,,SIG,,A) 2178000100033 MONIT-REF (,A.Prosdocimi+,J,JNE/AB,17,83,1963) 2178000100034 Author as it is mentioned in the JNE/AB. 2178000100035 COMMENT In the reference the measured cross sections are 2178000100036 extrapolated to the standard neutron energy of 2178000100037 0.0253 eV and compared with data from other authors. 2178000100038 CORRECTION Harmonics in the diffracted neutron beam. 2178000100039 Attenuation in the neutron beam between 2178000100040 boron and fissile samples. 2178000100041 Absorption of alphas from the monitor 2178000100042 reaction in the boron sample itself. 2178000100043 Scattering of monitor reaction alphas in 2178000100044 the aluminum backing. 2178000100045 Detector efficiency, including dead time and pile-up 2178000100046 alphas. 2178000100047 Decay alphas from contaminant fissile isotopes. 2178000100048 Geometry corrections. 2178000100049 ERR-ANALYS (ERR-1) Error in correction for neutron harmonics, 2178000100050 monitor reaction. 2178000100051 (ERR-2) Error in correction for neutron harmonics, 2178000100052 induced fission. 2178000100053 (ERR-3) Error in atomic density of boron. 2178000100054 (ERR-4) Error in effective sample areas, formed by 2178000100055 quadratically summing errors for production of 2178000100056 fission fragments, decay alphas,and alphas 2178000100057 from monitor reaction. 2178000100058 (ERR-5) Error in neutron attenuation between boron 2178000100059 and fissile samples. 2178000100060 (ERR-6) Error in the ratio of decay constant of 2178000100061 fissile isotope to its isotopic concentration. 2178000100062 (ERR-S) Total uncorrelated error,formed by 2178000100063 quadratically summing counting errors for 2178000100064 fission fragments, decay alphas, and alphas 2178000100065 from monitor reaction. 2178000100066 (ERR-T) Total error, including contribution 2178000100067 from the monitor error. 2178000100068 STATUS (TABLE) Data taken from CEA-R-2775. 2178000100069 HISTORY (19820210C) A.P.T. 2178000100070 (20140822A) SD: Updated to new date formats,lower case.2178000100071 Corrections according last EXFOR rules and Dict. 2178000100072 SF8=A was added to MONITOR reaction. FLAG moved to 2178000100073 Sub. 3. HALF-LIFE -> DECAY-DATA in Subents 2,3. 2178000100074 (20160907U) SD: STATUS 'SPSDD" added to Subent 003. 2178000100075 ENDBIB 73 0 2178000100076 NOCOMMON 0 0 2178000100077 ENDSUBENT 76 0 2178000199999 SUBENT 21780002 20140822 22402178000200001 BIB 5 17 2178000200002 REACTION (92-U-235(N,F),,SIG) 2178000200003 SAMPLE Four samples were used: 2178000200004 diam. mass backing isotop. composition 2178000200005 (mm) (mg) 2178000200006 1. 20. 1238. vynil 234U(0.108); 235U(0.9327); 2178000200007 236U(0.00205); 238U(0.0544) 2178000200008 2. 40. 1805. alum. 234U(0.0077); 235U(0.9010); 2178000200009 236U(0.0033); 238U(0.0880) 2178000200010 3. 40. 0.750 vynil 234U(0.00165); 235U(0.99216); 2178000200011 236U(0.000264); 238U(0.00594) 2178000200012 4. 40. 1372. vynil 234U(0.0077); 235U(0.9010); 2178000200013 236U(0.0033); 238U(0.0880) 2178000200014 COMMENT Fission fragments and decay alphas counted 2178000200015 with solid state detector. 2178000200016 DECAY-DATA (92-U-235,6.92E+08YR) (+- 0.09 x 10**8) Value taken 2178000200017 from A.Deruytter,JPR,24,939,196311 2178000200018 HISTORY (20140822A) SD: HALF-LIFE -> DECAY-DATA. 2178000200019 ENDBIB 17 0 2178000200020 COMMON 1 3 2178000200021 ERR-HL 2178000200022 YR 2178000200023 0.09E+08 2178000200024 ENDCOMMON 3 0 2178000200025 DATA 13 4 2178000200026 EN EN-ERR DATA ERR-T ERR-1 ERR-2 2178000200027 ERR-3 ERR-4 ERR-5 ERR-6 ERR-S MONIT 2178000200028 MONIT-ERR 2178000200029 EV EV B B PER-CENT PER-CENT 2178000200030 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT B 2178000200031 PER-CENT 2178000200032 3.2160E-02 4.0000E-05 5.1200E+02 1.1000E+01 2.0000E-01 7.0000E-012178000200033 2.3000E-01 1.0400E+00 3.0000E-01 1.5000E+00 6.8000E-01 6.7400E+022178000200034 3.0000E-01 2178000200035 6.2600E-02 1.0000E-04 3.3600E+02 8.0000E+00 2.0000E-01 7.0000E-012178000200036 6.0000E-01 5.2000E-01 1.0000E-01 1.8000E+00 7.1000E-01 4.8300E+022178000200037 3.0000E-01 2178000200038 6.2600E-02 1.0000E-04 3.3700E+02 1.0000E+01 2.0000E-01 7.0000E-012178000200039 6.0000E-01 5.2000E-01 1.0000E-01 2.0000E+00 1.8000E+00 4.8300E+022178000200040 3.0000E-01 2178000200041 6.2600E-02 1.0000E-04 3.3100E+02 8.0000E+00 2.0000E-01 7.0000E-012178000200042 6.0000E-01 5.2000E-01 1.0000E-01 2.0000E+00 6.3000E-01 4.8300E+022178000200043 3.0000E-01 2178000200044 ENDDATA 18 0 2178000200045 ENDSUBENT 44 0 2178000299999 SUBENT 21780003 20160907 22522178000300001 BIB 5 15 2178000300002 REACTION 1(94-PU-239(N,F),,SIG) 2178000300003 2(94-PU-239(N,F),,SIG) 2178000300004 SAMPLE Four samples were used: 2178000300005 diam. mass backing isotop. composition 2178000300006 (mm) (mg) 2178000300007 1. 40. 0.128 vynil 239Pu(0.993); 240Pu(0.007) 2178000300008 2. 20. 0.269 alum. 239Pu(0.993); 240Pu(0.007) 2178000300009 3. 40. 0.215 vynil 239Pu(0.993); 240Pu(0.007) 2178000300010 4. 40. 0.128 vynil 239Pu(0.993); 240Pu(0.007) 2178000300011 DECAY-DATA (94-PU-239,24413.YR) (+-30.yr) Value taken from 2178000300012 T.L.Markin,JIN,9,320,1959 2178000300013 STATUS (SPSDD,21520005) 2178000300014 HISTORY (20140822A) SD: HALF-LIFE -> DECAY-DATA. FLAG deleted. 2178000300015 Data split in two REACTIONs according to DETECTOR. 2178000300016 (20160907U) SD: STATUS "SPSDD" was added. 2178000300017 ENDBIB 15 0 2178000300018 COMMON 5 3 2178000300019 ERR-HL ERR-1 ERR-4 ERR-6 MONIT-ERR 2178000300020 YR PER-CENT PER-CENT PER-CENT PER-CENT 2178000300021 30. 0.2 0.52 0.1 0.3 2178000300022 ENDCOMMON 3 0 2178000300023 DATA 12 3 2178000300024 EN EN-ERR DATA 1ERR-T 1DATA 2ERR-T 22178000300025 ERR-2 ERR-3 ERR-5 ERR-S 1ERR-S 2MONIT 2178000300026 EV EV B B B B 2178000300027 PER-CENT PER-CENT PER-CENT PER-CENT PER-CENT B 2178000300028 3.216E-02 4.00E-05 6.290E+02 7.00 6.730E+02 1.30E+012178000300029 9.00E-01 2.30E-01 3.00E-01 3.30E-01 5.20E-01 6.740E+022178000300030 6.26E-02 1.00E-04 5.070E+02 9.00 2178000300031 1.30 6.00E-01 1.00E-01 7.40E-01 4.830E+022178000300032 2.75E-01 2.00E-03 3.2750E+03 3.00E+012178000300033 1.00E-01 2.30E-01 0.00 6.50E-01 2.310E+022178000300034 ENDDATA 10 0 2178000300035 ENDSUBENT 34 0 2178000399999 ENDENTRY 3 0 2178099999999