ENTRY 20766 20200925 22952076600000001 SUBENT 20766001 20200925 22952076600100001 BIB 16 58 2076600100002 TITLE A measurement of the subthreshold neutron fission 2076600100003 cross-section of plutonium-240 in the energy range 2076600100004 from 10 to 250 keV 2076600100005 AUTHOR (K.Wisshak, F.Kaeppeler) 2076600100006 INSTITUTE (2GERKFK) 2076600100007 REFERENCE (J,NSE,69,47,1979) 2076600100008 FACILITY (VDG,2GERKFK) Karlsruhe 3-MV pulsed Van de Graaff 2076600100009 repetition rate = 2.5 or 5 MHz 2076600100010 pulse width = 700 ps 2076600100011 average beam current = 10 to 15 uA 2076600100012 overall time resolution = 1.4 ns 2076600100013 energy resolution = 10 to 20 ns/m 2076600100014 INC-SOURCE (P-LI7) En < 90 keV 2076600100015 (P-T) En <250 keV 2076600100016 SAMPLE All samples were 30 mm in diameter. 2076600100017 The 240Pu sample, 235U sample, an empty dummy sample 2076600100018 and the Au sample (reference for capture measurement) 2076600100019 were cycled automatically in equal intervals 2076600100020 (94-PU-240,ENR=0.983) 2076600100021 240Pu (98.3%) with 239Pu (0.73%) and 241Pu (0.68%). 2076600100022 Pu oxide powder (3 g) enclosed in stainless-steel 2076600100023 cans (0.15 mm thick) and then welded in polyethylene 2076600100024 foils. 2076600100025 (92-U-235,ENR=0.929) 2076600100026 Metallic uranium disk (0.7 mm thick). 2076600100027 DETECTOR (SCIN) Cylindrical NE-213 liquid scintillator (100 mm 2076600100028 diam., 30 mm thick) located at 120 deg with respect 2076600100029 to the beam direction and ~180 mm from the sample. 2076600100030 PART-DET (N) Prompt fission neutron detection 2076600100031 METHOD (PLSED) Pulse-shape discriminator used with NE-213 2076600100032 MONITOR ((92-U-235(N,F),PR,NU)/(94-PU-240(N,F),PR,NU)) 2076600100033 The thermal ratio 0.84 assumed as constant 2076600100034 MONIT-REF (,F.Manero+,J,REA,10,637,1972) 2076600100035 CORRECTION Corrected for 2076600100036 - time dependent and independent background 2076600100037 - fissions of 239Pu and 241Pu impurities 2076600100038 - isotopic impurities in the 235U sample (<0.6%) 2076600100039 - effect of different fission neutron spectra 2076600100040 - neutron scattering in polyethylene foil 2076600100041 - multiple scattering and self shielding 2076600100042 ERR-ANALYS (EN-ERR) Time resolution (1.4 ns), sample thickness 2076600100043 and flight path uncertainties 2076600100044 (ERR-T) Total uncertainty 2076600100045 (ERR-S) Statistical uncertainty 2076600100046 (ERR-SYS) Total systematic uncertainty 2076600100047 (ERR-1) Unfolding procedure (5.0%)2076600100048 (ERR-2) Neutrons above threshold (2.0%)2076600100049 (ERR-3) Multiple scattering and self-shielding (0.4%)2076600100050 (ERR-4) Neutron flux (0.4%)2076600100051 STATUS (TABLE) Table II of Nucl.Sci.Eng.69(1979)47 2076600100052 HISTORY (19780807C) 2076600100053 (19781024E) 2076600100054 (19800208A) Main reference added. 2076600100055 (19800213E) 2076600100056 (19801104A) RATIO-ERR headings changed and DATA correct2076600100057 with a factor of 100. 2076600100058 (19801124E) 2076600100059 (20200925A) On. Recompiled. 2076600100060 ENDBIB 58 0 2076600100061 COMMON 5 3 2076600100062 MONIT ERR-1 ERR-2 ERR-3 ERR-4 2076600100063 NO-DIM PER-CENT PER-CENT PER-CENT PER-CENT 2076600100064 0.84 5.0 2.0 0.4 0.4 2076600100065 ENDCOMMON 3 0 2076600100066 ENDSUBENT 65 0 2076600199999 SUBENT 20766002 20200925 22952076600200001 BIB 4 10 2076600200002 REACTION ((94-PU-240(N,F),,SIG)/(92-U-235(N,F),,SIG)) 2076600200003 METHOD (TOF) Flight path length = 66.0 mm (Run IV) 2076600200004 ERR-ANALYS (ERR-5,3.7,4.0) Flight path, 240Pu (3.7-4.0%) 2076600200005 (ERR-6,0.5,3.8) Constant background, 240Pu (0.5-3.8%) 2076600200006 (ERR-7) Flight path, 235U (1.6%) 2076600200007 (ERR-8,0.1,0.6) Constant background, 235U (0.1-0.6%) 2076600200008 (ERR-9,2.8,6.3) Isotopic impurities (2.8-6.3%) 2076600200009 (ERR-10,2.0,3.0) Scattering in polyethylene (2.0-3.0%) 2076600200010 HISTORY (19801104A) 2076600200011 (20200925A) On. ERR-ANALYS added. Data checked. 2076600200012 ENDBIB 10 0 2076600200013 COMMON 1 3 2076600200014 ERR-7 2076600200015 PER-CENT 2076600200016 1.6 2076600200017 ENDCOMMON 3 0 2076600200018 DATA 6 9 2076600200019 EN EN-ERR DATA ERR-S ERR-SYS ERR-T 2076600200020 KEV KEV NO-DIM PER-CENT PER-CENT PER-CENT 2076600200021 49.1 4.5 2.60E-02 6.5 10.6 12.4 2076600200022 56.2 5.4 2.59E-02 5.7 10.4 11.9 2076600200023 64.9 6.5 3.06E-02 4.0 9.4 10.2 2076600200024 75.7 7.9 3.99E-02 2.8 8.3 8.8 2076600200025 89.6 9.8 3.70E-02 2.8 8.5 8.9 2076600200026 107.6 12.6 3.42E-02 2.7 8.6 9.0 2076600200027 131.7 16.6 3.84E-02 2.3 8.4 8.7 2076600200028 164.9 22.6 4.70E-02 1.7 8.1 8.3 2076600200029 212.5 31.6 6.20E-02 1.8 7.8 8.0 2076600200030 ENDDATA 11 0 2076600200031 ENDSUBENT 30 0 2076600299999 SUBENT 20766003 20200925 22952076600300001 BIB 4 10 2076600300002 REACTION ((94-PU-240(N,F),,SIG)/(92-U-235(N,F),,SIG)) 2076600300003 METHOD (TOF) Flight path length = 135 mm (Run I) 2076600300004 ERR-ANALYS (ERR-5,1.8,2.0) Flight path, 240Pu (1.8-2.0%) 2076600300005 (ERR-6,1.0,3.9) Constant background, 240Pu (1.0-3.9%) 2076600300006 (ERR-7) Flight path, 235U (0.8%) 2076600300007 (ERR-8,,0.1) Constant background, 235U (<0.1%) 2076600300008 (ERR-9,2.7,5.9) Isotopic impurities (2.7-5.9%) 2076600300009 (ERR-10,1.0,1.5) Scattering in polyethylene (1.0-1.5%) 2076600300010 HISTORY (19801104A) 2076600300011 (20200925A) On. ERR-ANALYS added. Data checked. 2076600300012 ENDBIB 10 0 2076600300013 COMMON 1 3 2076600300014 ERR-7 2076600300015 PER-CENT 2076600300016 0.8 2076600300017 ENDCOMMON 3 0 2076600300018 DATA 6 21 2076600300019 EN EN-ERR DATA ERR-S ERR-SYS ERR-T 2076600300020 KEV KEV NO-DIM PER-CENT PER-CENT PER-CENT 2076600300021 18.9 0.5 3.76E-02 3.2 8.1 8.7 2076600300022 19.8 0.6 4.29E-02 2.5 7.3 7.7 2076600300023 20.9 0.6 4.12E-02 2.7 7.5 8.0 2076600300024 22.0 0.7 3.54E-02 2.7 7.7 8.2 2076600300025 23.2 0.7 3.13E-02 2.9 8.4 8.9 2076600300026 24.5 0.8 3.43E-02 2.5 8.1 8.5 2076600300027 25.9 0.8 3.53E-02 2.1 7.7 8.0 2076600300028 27.5 0.9 3.48E-02 2.1 7.9 8.2 2076600300029 29.1 0.9 3.92E-02 1.8 7.5 7.7 2076600300030 31.0 1.0 4.45E-02 1.6 7.4 7.6 2076600300031 33.0 1.1 4.91E-02 1.3 6.9 7.0 2076600300032 35.3 1.2 5.29E-02 1.2 6.9 7.0 2076600300033 37.8 1.4 5.04E-02 1.3 7.0 7.1 2076600300034 40.5 1.5 4.76E-02 1.3 7.1 7.2 2076600300035 43.6 1.7 4.82E-02 1.2 7.0 7.1 2076600300036 47.1 1.9 3.90E-02 1.4 7.4 7.5 2076600300037 50.9 2.1 2.97E-02 1.7 8.5 8.7 2076600300038 55.3 2.4 2.71E-02 1.7 8.6 8.8 2076600300039 60.3 2.7 3.41E-02 1.5 7.7 7.8 2076600300040 66.0 3.1 3.94E-02 1.5 7.3 7.5 2076600300041 72.5 3.5 3.93E-02 1.9 7.6 7.8 2076600300042 ENDDATA 23 0 2076600300043 ENDSUBENT 42 0 2076600399999 SUBENT 20766004 20200925 22952076600400001 BIB 4 10 2076600400002 REACTION ((94-PU-240(N,F),,SIG)/(92-U-235(N,F),,SIG)) 2076600400003 METHOD (TOF) Flight path length = 135 mm (Run II) 2076600400004 ERR-ANALYS (ERR-5,1.8,2.0) Flight path, 240Pu (1.8-2.0%) 2076600400005 (ERR-6,0.4,1.8) Constant background, 240Pu (0.4-1.8%) 2076600400006 (ERR-7) Flight path, 235U (0.8%) 2076600400007 (ERR-8,,0.1) Constant background, 235U (<0.1%) 2076600400008 (ERR-9,2.5,5.5) Isotopic impurities (2.5-5.5%) 2076600400009 (ERR-10,1.0,1.5) Scattering in polyethylene (1.0-1.5%) 2076600400010 HISTORY (19801104A) 2076600400011 (20200925A) On. ERR-ANALYS added. Data checked. 2076600400012 ENDBIB 10 0 2076600400013 COMMON 1 3 2076600400014 ERR-7 2076600400015 PER-CENT 2076600400016 0.8 2076600400017 ENDCOMMON 3 0 2076600400018 DATA 6 21 2076600400019 EN EN-ERR DATA ERR-S ERR-SYS ERR-T 2076600400020 KEV KEV NO-DIM PER-CENT PER-CENT PER-CENT 2076600400021 18.9 0.5 4.48E-02 3.8 7.0 8.0 2076600400022 19.8 0.6 3.82E-02 4.6 7.5 8.8 2076600400023 20.9 0.6 4.21E-02 3.0 6.7 7.3 2076600400024 22.0 0.7 3.67E-02 3.8 7.4 8.3 2076600400025 23.2 0.7 2.66E-02 4.5 9.2 10.2 2076600400026 24.5 0.8 3.12E-02 3.6 8.1 8.9 2076600400027 25.9 0.8 3.87E-02 2.5 7.3 7.7 2076600400028 27.5 0.9 3.73E-02 2.7 7.7 8.2 2076600400029 29.1 0.9 4.06E-02 2.2 7.2 7.5 2076600400030 31.0 1.0 4.45E-02 2.0 7.1 7.4 2076600400031 33.0 1.1 5.17E-02 1.7 6.9 7.1 2076600400032 35.3 1.2 5.46E-02 1.5 6.8 7.0 2076600400033 37.8 1.4 5.10E-02 1.7 7.1 7.3 2076600400034 40.5 1.5 5.17E-02 1.4 6.8 6.9 2076600400035 43.6 1.7 4.79E-02 1.6 7.1 7.3 2076600400036 47.1 1.9 4.09E-02 1.6 7.2 7.4 2076600400037 50.9 2.1 3.44E-02 1.8 7.7 7.9 2076600400038 55.3 2.4 3.07E-02 2.0 8.2 8.4 2076600400039 60.3 2.7 3.24E-02 1.8 7.9 8.1 2076600400040 66.0 3.1 4.05E-02 1.6 7.2 7.4 2076600400041 72.5 3.5 4.93E-02 1.6 6.9 7.1 2076600400042 ENDDATA 23 0 2076600400043 ENDSUBENT 42 0 2076600499999 SUBENT 20766005 20200925 22952076600500001 BIB 4 10 2076600500002 REACTION ((94-PU-240(N,F),,SIG)/(92-U-235(N,F),,SIG)) 2076600500003 METHOD (TOF) Flight path length = 68.5 mm (Run III) 2076600500004 ERR-ANALYS (ERR-5,3.6,3.9) Flight path, 240Pu (3.6-3.9%) 2076600500005 (ERR-6,0.1,3.9) Constant background, 240Pu (0.1-3.9%) 2076600500006 (ERR-7) Flight path, 235U (1.6%) 2076600500007 (ERR-8,,0.2) Constant background, 235U (<0.2%) 2076600500008 (ERR-9,2.5,6.9) Isotopic impurities (2.5-6.9%) 2076600500009 (ERR-10,1.0,2.5) Scattering in polyethylene (1.0-2.5%) 2076600500010 HISTORY (19801104A) 2076600500011 (20200925A) On. ERR-ANALYS added. Data checked. 2076600500012 ENDBIB 10 0 2076600500013 COMMON 1 3 2076600500014 ERR-7 2076600500015 PER-CENT 2076600500016 1.6 2076600500017 ENDCOMMON 3 0 2076600500018 DATA 6 21 2076600500019 EN EN-ERR DATA ERR-S ERR-SYS ERR-T 2076600500020 KEV KEV NO-DIM PER-CENT PER-CENT PER-CENT 2076600500021 9.1 0.6 2.59E-02 7.3 9.5 12.0 2076600500022 9.7 0.7 1.89E-02 8.7 10.5 13.6 2076600500023 10.4 0.7 3.33E-02 4.9 8.5 9.8 2076600500024 11.1 0.8 4.46E-02 3.0 7.8 8.4 2076600500025 11.9 0.9 3.65E-02 3.3 8.2 8.8 2076600500026 12.9 1.0 3.41E-02 2.9 8.1 8.6 2076600500027 13.9 1.0 2.74E-02 3.2 8.8 9.4 2076600500028 15.1 1.1 2.43E-02 3.4 9.1 9.7 2076600500029 16.5 1.3 2.76E-02 2.6 8.8 9.2 2076600500030 18.0 1.4 2.98E-02 2.2 8.8 9.1 2076600500031 19.8 1.6 3.48E-02 1.8 8.0 8.2 2076600500032 21.8 1.8 3.41E-02 1.6 8.0 8.2 2076600500033 24.2 2.0 3.15E-02 1.5 8.4 8.5 2076600500034 27.0 2.2 3.20E-02 1.5 8.8 8.9 2076600500035 30.3 2.6 3.94E-02 1.1 8.1 8.2 2076600500036 34.3 3.0 5.08E-02 0.9 7.8 7.9 2076600500037 39.1 3.5 5.22E-02 0.8 7.7 7.7 2076600500038 44.9 4.3 4.28E-02 0.9 8.0 8.0 2076600500039 52.1 5.2 3.06E-02 1.1 9.1 9.2 2076600500040 61.3 6.3 2.96E-02 0.9 8.8 8.8 2076600500041 73.1 8.0 4.07E-02 0.7 8.1 8.1 2076600500042 ENDDATA 23 0 2076600500043 ENDSUBENT 42 0 2076600599999 ENDENTRY 5 0 2076699999999