ENTRY 14795 20250207 151814795000 1 SUBENT 14795001 20250207 151814795001 1 BIB 11 30 14795001 2 TITLE Fast-neutron-induced fission of 240Pu and 242Pu 14795001 3 AUTHOR (A.Pica,A.T.Chemey,W.Loveland) 14795001 4 REFERENCE (J,PR/C,106,044603,2022) 14795001 5 #doi:10.1103/PhysRevC.106.044603 14795001 6 INSTITUTE (1USAORU) 14795001 7 FACILITY (LINAC,1USALAS) 15R beam line at the Los Alamos 14795001 8 National Laboratory, Los Alamos Neutron Science 14795001 9 Center at the Weapons Neutron Research (LANSCE-WNR) 14795001 10 facility. 14795001 11 INC-SOURCE (SPALL) "White spectrum" neutron beams were generated 14795001 12 from an unmoderated tungsten spallation source using 14795001 13 the 800-MeV proton beam from the LANSCE linear 14795001 14 accelerator. 14795001 15 DETECTOR (SI) Fission fragments were detected by nine pairs of 14795001 16 1-cm2 Si p-i-n diode detectors (Hamamatsu S3590-09) 14795001 17 positioned 3.5 cm from the target. 14795001 18 METHOD (TOF) The time of flight of each interacting neutron 14795001 19 was measured using a timing pulse from a Si p-i-n 14795001 20 diode and the accelerator rf signal. The distance 14795001 21 from the spallation target to the Pu targets was 14795001 22 measured to be 1384.9 +- 1.1 cm. The solid angle 14795001 23 covered by the Si p-i-n diodes was ~11% of 2pi. 14795001 24 ANALYSIS The 2E method was used to measure the fission product 14795001 25 masses and their TKE by detecting the fission 14795001 26 products and determining their energies after neutron 14795001 27 emission. 14795001 28 CORRECTION Corrections for PHD, the pulse-height defect, and 14795001 29 energy loss of fragments in the target and backing 14795001 30 foils are also applied. 14795001 31 HISTORY (20250207C) BP 14795001 32 ENDBIB 30 0 14795001 33 NOCOMMON 0 0 14795001 34 ENDSUBENT 33 0 1479500199999 SUBENT 14795002 20250207 151814795002 1 BIB 5 17 14795002 2 REACTION 1(94-PU-240(N,F),PRE,AKE,LF+HF) 14795002 3 2(94-PU-240(N,F),SEC,AKE,LF+HF) 14795002 4 REL-REF (A,10712001,D.R.Nethaway+,J,PR/C,16,1907,1977) 14795002 5 SAMPLE (94-PU-240,ENR=0.99874) The plutonium targets were 14795002 6 prepared by vapor deposition using the method. The 14795002 7 targets consisted of 2-cm-diameter circular deposits 14795002 8 of the Pu isotope on a thin C backing. The target 14795002 9 thickness was 72.3 microg/cm2 (240Pu) (as measured by 14795002 10 alpha spectroscopy). The source material for the 14795002 11 240Pu target was 99.874 wt% 240Pu. The assumed 14795002 12 chemical composition of the targets was that of PuF4. 14795002 13 The C backing thickness was 100 microg/cm2. The 14795002 14 targets were at an angle of 45 degree with respect to 14795002 15 the incident beam. 14795002 16 ERR-ANALYS (DATA-ERR) Error bars are uncertainty on measurements 14795002 17 from the Gaussian fits. 14795002 18 STATUS (TABLE,,A.Pica,J,PR/C,106,044603,2022) - Table V 14795002 19 ENDBIB 17 0 14795002 20 NOCOMMON 0 0 14795002 21 DATA 6 10 14795002 22 EN-MIN EN-MAX DATA 1DATA-ERR 1DATA 2DATA-ERR 214795002 23 MEV MEV MEV MEV MEV MEV 14795002 24 0.55 1.01 177.9 0.5 175.9 0.514795002 25 1.01 1.47 178.0 0.4 175.8 0.414795002 26 1.47 2.17 177.1 0.5 175.0 0.514795002 27 2.17 3.04 177.2 0.5 174.8 0.514795002 28 3.04 4.64 175.1 0.5 173.1 0.514795002 29 4.64 7.35 175.7 0.5 173.2 0.514795002 30 7.35 11.68 175.2 0.5 172.8 0.514795002 31 11.68 24.21 173.2 0.5 170.3 0.414795002 32 24.21 48.34 171.5 0.5 168.5 0.414795002 33 48.34 100. 170.0 0.5 166.6 0.514795002 34 ENDDATA 12 0 14795002 35 ENDSUBENT 34 0 1479500299999 SUBENT 14795003 20250207 151814795003 1 BIB 5 17 14795003 2 REACTION 1(94-PU-242(N,F),PRE,AKE,LF+HF) 14795003 3 2(94-PU-242(N,F),SEC,AKE,LF+HF) 14795003 4 REL-REF (A,21983001,I.Winkelmann+,J,PR/C,30,934,1984) 14795003 5 SAMPLE (94-PU-242,ENR=0.99964) The plutonium targets were 14795003 6 prepared by vapor deposition using the method. The 14795003 7 targets consisted of 2-cm-diameter circular deposits 14795003 8 of the Pu isotope on a thin C backing. The target 14795003 9 thickness was 63.0 microg/cm2 (242Pu) (as measured by 14795003 10 alpha spectroscopy). The source material for the 242Pu 14795003 11 target was 99.964 wt% 242Pu. The assumed chemical 14795003 12 composition of the targets was that of PuF4. The C 14795003 13 backing thickness was 100 microg/cm2. The targets were 14795003 14 at an angle of 45 degree with respect to the incident 14795003 15 beam. 14795003 16 ERR-ANALYS (DATA-ERR) Error bars are uncertainty on measurements 14795003 17 from the Gaussian fits. 14795003 18 STATUS (TABLE,,A.Pica,J,PR/C,106,044603,2022) - Table VI 14795003 19 ENDBIB 17 0 14795003 20 NOCOMMON 0 0 14795003 21 DATA 6 10 14795003 22 EN-MIN EN-MAX DATA 1DATA-ERR 1DATA 2DATA-ERR 214795003 23 MEV MEV MEV MEV MEV MEV 14795003 24 0.62 1.09 179.5 0.4 177.3 0.414795003 25 1.09 1.55 178.7 0.4 176.8 0.414795003 26 1.55 2.26 179.4 0.4 177.1 0.414795003 27 2.26 3.28 177.7 0.4 175.2 0.414795003 28 3.38 5.10 178.0 0.4 175.8 0.414795003 29 5.10 8.36 177.8 0.4 175.3 0.414795003 30 8.36 13.97 176.5 0.4 174.3 0.414795003 31 13.97 29.86 174.7 0.4 171.9 0.414795003 32 29.86 42.50 173.1 0.4 170.1 0.414795003 33 42.50 100. 171.8 0.4 168.5 0.414795003 34 ENDDATA 12 0 14795003 35 ENDSUBENT 34 0 1479500399999 ENDENTRY 3 0 1479599999999