ENTRY 23056 20220128 23102305600000001 SUBENT 23056001 20220128 23102305600100001 BIB 14 89 2305600100002 TITLE New experimental and theoretical results for the U-235 2305600100003 fission neutron spectrum. 2305600100004 AUTHOR (N.V.Kornilov, F.-J.Hambsch, I.Fabry, S.Oberstedt, 2305600100005 S.P.Simakov, A.Vorobyev) 2305600100006 REFERENCE (C,2007NICE,1,387,2007) 2305600100007 #doi:10.1051/ndata:07735 2305600100008 (C,2007CORSEN,,125,2007) 2305600100009 (P,EUR-23440,28,2008) EN. 2305600100010 #doi:10.2787/65683 2305600100011 INSTITUTE (2ZZZGEL) N.V.Kornilov,F.-J.Hambsch,I.Fabry,S.Oberstedt2305600100012 (2GERKFK) S.P.Simakov. 2305600100013 (4RUSLIN) A.Vorobyev 2305600100014 INC-SOURCE (P-LI7) Pulsed proton beam of about 1-1.5 ns FWHM at 2305600100015 repetition rate 1.25 MHz, average current 0.5 microA. 2305600100016 Li-7(p,n) reaction on LiF target of 596 microg/cm**2 2305600100017 thickness. 2305600100018 INC-SPECT Mono-energetic neutrons of 0.52 MeV average energy. 2305600100019 The actual neutron energy range due to LiF target 2305600100020 thickness and geometrical factor extended from 2305600100021 0.41 MeV to 0.58 MeV. 2305600100022 FACILITY (VDG,2ZZZGEL) 7-MV Van de Graaff accelerator. 2305600100023 Pulse mode operation at VdG with FWHM between 1-1.5 ns.2305600100024 METHOD (TOF) Fast neutron time-of-flight technique. 2305600100025 Time resolution of neutron TOF spectrometer consists 2305600100026 of components: detector resolution,shape of pulse from2305600100027 accelerator,neutron distribution inside the sample. 2305600100028 (PSD) Traditional neutron-gamma-ray discrimination 2305600100029 technique (pulse-shape analysis) was applied to 2305600100030 gamma-ray reduction. 2305600100031 SAMPLE Metallic U-235 sample (93.15% enrichment) ,weight 2305600100032 161.28 g consists of 10 concentric rings canned in an 2305600100033 aluminum container of 0.2 mm wall thickness. Outside 2305600100034 diameter of rings 3.00 cm, inside - 2.12 cm, height 2305600100035 2.41 cm. 2305600100036 Similar sized lead sample was applied to background 2305600100037 measurements. 2305600100038 Sample was placed at 5 cm and 8 cm from the neutron 2305600100039 producing target at 0 deg. angle with low-mass holder. 2305600100040 DETECTOR (SPEC,SCIN) Up to three NE213-equivalent liquid 2305600100041 scintillators of 10.2 cm diameter and 5.1 cm or 2.5 cm 2305600100042 length, coupled to XP4312/B photomultipliers. All were 2305600100043 placed in large collimating shields made of lithium 2305600100044 carbonate, paraffin, lead. 2305600100045 The distances between the center of scintillators and 2305600100046 sample were 273.0 +- 0.5 cm for the detector at 90 deg 2305600100047 and 240.0 +- 0.5 cm for the one at 120 deg relative to 2305600100048 the proton beam axis detectors. The flight path was 2305600100049 224 +- 1 cm when using the three identical detectors 2305600100050 (5.1 cm length) at 90, 150, and 120 deg. Additional 2305600100051 copper cylinder was placed between target and detectors2305600100052 to reduce the direct gamma-ray and neutron flux from 2305600100053 the target. Traditional n/g discrimination technique 2305600100054 was applied to gamma-ray reduction. 2305600100055 Another detector based on a PilotU plastic scintillator2305600100056 (diameter 3 cm, height 2 cm) mounted to XP2020Q 2305600100057 photomultiplier as monitor of the proton pulses. 2305600100058 Detector efficiencies were measured for all neutron 2305600100059 detectors simultaneously, relative to 252-Cf standard 2305600100060 spectrum - 252-Cf source inside a low mass, fast 2305600100061 ionization chamber developed at IRMM and put at place 2305600100062 of the U-sample keeping the same geometry. Total time 2305600100063 resolution (FWHM) for a neutron threshold of about 2305600100064 0.5MeV,estimated from the 252Cf efficiency measurement,2305600100065 is 1.5 ns for the detector at 90 deg. and 1.3 ns for 2305600100066 the one at 120 deg. The gamma-ray suppression was about2305600100067 1/200 for both detectors. 2305600100068 CORRECTION Energy distributions were corrected for detector 2305600100069 efficiencies,for neutron multiple scattering in sample,2305600100070 for time resolution. 2305600100071 ANALYSIS TOF spectra for uranium and lead were normalized to the2305600100072 elastic peak. 2305600100073 Exp. PFNS were normalized to unity and the average 2305600100074 secondary neutron energy was calculated. 2305600100075 Maxwellian spectrum was fitted in the energy range of 2305600100076 0.7 - 1.5 MeV and 9-11 MeV to the measured spectrum, 2305600100077 and extrapolation to zero and to 20 MeV was performed. 2305600100078 ADD-RES Average ratio of prompt neutron energy distribution 2305600100079 at 90 deg right to 120 deg left; Prompt fission neutron2305600100080 energy spectra at several angles were received from 2305600100081 first author, but were not included in EXFOR according 2305600100082 to the comment from IRMM, Dr.Peter Rullhusen. 2305600100083 HISTORY (20090316C) S.M. 2305600100084 (20100202U) Reference 2007CORSEN added 2305600100085 (20100713U) M.M. Reference EUR-23440 page was corrected2305600100086 Misprints in authors' names were corrected. 2305600100087 (20110711A) REACTION code in SAN 009, 010 corrected 2305600100088 after MEMO CP-D635 2305600100089 (20201028A) SD: Subents 006-008 corrected. 2305600100090 (20220128A) SD: Subents 008-010 deleted (see ADD-RES). 2305600100091 ENDBIB 89 0 2305600100092 COMMON 1 3 2305600100093 EN 2305600100094 MEV 2305600100095 0.52 2305600100096 ENDCOMMON 3 0 2305600100097 ENDSUBENT 96 0 2305600199999 SUBENT 23056002 20090303 22102305600200001 BIB 6 14 2305600200002 REACTION (92-U-235(N,F),PR,AKE/DA,N) Average energy of prompt 2305600200003 fast fission neutrons. 2305600200004 EXP-YEAR (2006) July of 2006. 2305600200005 METHOD Three runs: 2305600200006 Neutrons collected Run duration,h 2305600200007 1 8.0E+5 37.0 2305600200008 2 1.1E+6 42.1 2305600200009 3 8.5E+5 39.2 2305600200010 FLAG (1.) Run 1 . 2305600200011 (2.) Run 2 . 2305600200012 (3.) Run 3 . 2305600200013 ERR-ANALYS (DATA-ERR) Accuracy of average energy estimated . 2305600200014 STATUS (TABLE) Table 1 of C,2007NICE. 2305600200015 (PRELM) Preliminary data. 2305600200016 ENDBIB 14 0 2305600200017 COMMON 1 3 2305600200018 DATA-ERR 2305600200019 MEV 2305600200020 0.020 2305600200021 ENDCOMMON 3 0 2305600200022 DATA 3 6 2305600200023 ANG DATA FLAG 2305600200024 ADEG MEV NO-DIM 2305600200025 90. 2.018 1. 2305600200026 90. 2.022 2. 2305600200027 90. 2.014 3. 2305600200028 120. 2.087 1. 2305600200029 120. 2.103 2. 2305600200030 120. 2.092 3. 2305600200031 ENDDATA 8 0 2305600200032 ENDSUBENT 31 0 2305600299999 SUBENT 23056003 20090303 22102305600300001 BIB 6 17 2305600300002 REACTION (92-U-235(N,F),PR,AKE/DA,N) Average energy of prompt 2305600300003 fast fission neutrons. 2305600300004 EXP-YEAR (2006) July of 2006. 2305600300005 METHOD Average for 3 runs. 2305600300006 Preliminary values from C,2007NICE were 2305600300007 2.018+- 0.020 MeV and 2.094 +- 0.020 MeV for angles 2305600300008 90 deg and 120 deg, respectively. 2305600300009 ERR-ANALYS (DATA-ERR) Accuracy of average energy was estimated on 2305600300010 the base of detailed analysis of all incorporated 2305600300011 corrections and possible uncertainties. 2305600300012 CORRECTION Time resolution correction for the measured spectra was2305600300013 recalculated for experiment of 2006 year. 2305600300014 An additional energy dependence in neutron detector 2305600300015 efficiency at E > 4 MeV was taken into account. 2305600300016 STATUS (TABLE) Table 1 of R,EUR-23440,30,2008. 2305600300017 (DEP,23056002) 2305600300018 (PRELM) Preliminary data. 2305600300019 ENDBIB 17 0 2305600300020 COMMON 1 3 2305600300021 DATA-ERR 2305600300022 MEV 2305600300023 0.010 2305600300024 ENDCOMMON 3 0 2305600300025 DATA 2 2 2305600300026 ANG DATA 2305600300027 ADEG MEV 2305600300028 90. 2.004 2305600300029 120. 2.076 2305600300030 ENDDATA 4 0 2305600300031 ENDSUBENT 30 0 2305600399999 SUBENT 23056004 20090303 22102305600400001 BIB 4 8 2305600400002 REACTION (92-U-235(N,F),PR,AKE/DA,N) Average energy of prompt 2305600400003 fast fission neutrons. 2305600400004 EXP-YEAR (2007) April of 2007. 2305600400005 ERR-ANALYS (DATA-ERR) Accuracy of average energy was estimated on 2305600400006 the base of detailed analysis of all incorporated 2305600400007 corrections and possible uncertainties. 2305600400008 STATUS (TABLE) Table 1 of R,EUR-23440,30,2008. 2305600400009 (PRELM) Preliminary data. 2305600400010 ENDBIB 8 0 2305600400011 COMMON 1 3 2305600400012 DATA-ERR 2305600400013 MEV 2305600400014 0.010 2305600400015 ENDCOMMON 3 0 2305600400016 DATA 2 3 2305600400017 ANG DATA 2305600400018 ADEG MEV 2305600400019 90. 2.002 2305600400020 120. 2.050 2305600400021 150. 2.026 2305600400022 ENDDATA 5 0 2305600400023 ENDSUBENT 22 0 2305600499999 SUBENT 23056005 20090303 22102305600500001 BIB 5 10 2305600500002 REACTION (92-U-235(N,F),PR,AKE/DA,N) Average energy of prompt 2305600500003 fast fission neutrons. 2305600500004 EXP-YEAR (2008) January of 2008. 2305600500005 ERR-ANALYS (DATA-ERR) Accuracy of average energy was estimated on 2305600500006 the base of detailed analysis of all incorporated 2305600500007 corrections and possible uncertainties. 2305600500008 FLAG (1.) For left detector measurement. 2305600500009 (2.) For right detector measurement. 2305600500010 STATUS (TABLE) Table 1 of R,EUR-23440,30,2008. 2305600500011 (PRELM) Preliminary data. 2305600500012 ENDBIB 10 0 2305600500013 COMMON 1 3 2305600500014 DATA-ERR 2305600500015 MEV 2305600500016 0.010 2305600500017 ENDCOMMON 3 0 2305600500018 DATA 3 3 2305600500019 ANG DATA FLAG 2305600500020 ADEG MEV NO-DIM 2305600500021 90. 2.021 2. 2305600500022 90. 2.007 1. 2305600500023 150. 1.975 2. 2305600500024 ENDDATA 5 0 2305600500025 ENDSUBENT 24 0 2305600599999 SUBENT 23056006 20201028 22962305600600001 BIB 5 11 2305600600002 REACTION ((92-U-235(N,F)0-NN-1,PR,DA/DE)// 2305600600003 (92-U-235(N,F)0-NN-1,PR,DA/DE)) Average ratio of 2305600600004 prompt neutron energy distribution at 90 deg 2305600600005 to 120 deg. 2305600600006 EXP-YEAR (2006) July of 2006. 2305600600007 ERR-ANALYS (DATA-ERR) Not specified. 2305600600008 STATUS (TABLE) Text of C,2007NICE, page 388. 2305600600009 (PRELM) Preliminary data. 2305600600010 (DEP,23056008) 2305600600011 HISTORY (20201028A) SD: SF4=NN-1 added, SF7=N deleted from 2305600600012 REACTION code. 2305600600013 ENDBIB 11 0 2305600600014 COMMON 2 3 2305600600015 ANG-NM ANG-DN 2305600600016 ADEG ADEG 2305600600017 90. 120. 2305600600018 ENDCOMMON 3 0 2305600600019 DATA 4 1 2305600600020 E-MIN E-MAX DATA DATA-ERR 2305600600021 MEV MEV NO-DIM NO-DIM 2305600600022 6. 10. 1.022 0.015 2305600600023 ENDDATA 3 0 2305600600024 ENDSUBENT 23 0 2305600699999 SUBENT 23056007 20201028 22962305600700001 BIB 4 9 2305600700002 REACTION ((92-U-235(N,F)0-NN-1,PR,DA/DE)// 2305600700003 (92-U-235(N,F)0-NN-1,PR,DA/DE)) Average ratio of 2305600700004 prompt neutron energy distribution at 90 deg right 2305600700005 to 90 deg left. 2305600700006 ERR-ANALYS (DATA-ERR) Not specified. 2305600700007 STATUS (TABLE) Table 2 of R,EUR-23440,30,2008. 2305600700008 (PRELM) Preliminary data. 2305600700009 HISTORY (20201028A) SD: SF4=NN-1 added, SF7=N deleted from 2305600700010 REACTION code. 2305600700011 ENDBIB 9 0 2305600700012 COMMON 2 3 2305600700013 ANG-NM ANG-DN 2305600700014 ADEG ADEG 2305600700015 90. -90. 2305600700016 ENDCOMMON 3 0 2305600700017 DATA 4 7 2305600700018 E-MIN E-MAX DATA DATA-ERR 2305600700019 MEV MEV NO-DIM NO-DIM 2305600700020 0.8 2. 0.999 0.003 2305600700021 2. 3. 1.010 0.002 2305600700022 3. 4. 1.020 0.005 2305600700023 4. 5. 1.034 0.004 2305600700024 5. 6. 1.009 0.005 2305600700025 6. 8. 1.051 0.006 2305600700026 8. 10. 0.970 0.032 2305600700027 ENDDATA 9 0 2305600700028 ENDSUBENT 27 0 2305600799999 NOSUBENT 23056008 20220128 23102305600800001 NOSUBENT 23056009 20220128 23102305600900001 NOSUBENT 23056010 20220128 23102305601000001 ENDENTRY 10 0 2305699999999