ENTRY 14601 20200113 14631460100000001 SUBENT 14601001 20200113 14631460100100001 BIB 11 57 1460100100002 TITLE Determining the average prompt-fission-neutron 1460100100003 multiplicity for 239Pu(n,f) via a 240Pu(a,af) 1460100100004 surrogate reaction 1460100100005 AUTHOR (B.S.Wang,J.T.Harke,O.A.Akindele,R.J.Casperson, 1460100100006 R.O.Hughes,J.D.Koglin,K.Kolos,E.B.Norman,S.Ota, 1460100100007 A.Saastamoinen) 1460100100008 INSTITUTE (1USALRL,1USABRK,1USATAM) 1460100100009 REFERENCE (J,PR/C,100,064609,2019) 1460100100010 FACILITY (CYCLO,1USATAM) Experiment performed using K150 1460100100011 cyclotron at the Texas A&M University Cyclotron 1460100100012 Institute 1460100100013 SAMPLE (94-PU-240,ENR=0.99995) 1460100100014 (94-PU-238,ENR=0.0000493) 1460100100015 240Pu material was electroplated on 100 mu-g/cm2 1460100100016 thick natural-carbon foil covering circular area 1460100100017 of 1.90 cm in diameter. Activity of 240Pu was 1460100100018 67.374 mu-Ci, thickness was 104.078 mu-g/cm2. 1460100100019 Carbon foil was glued by epoxy glue onto Al frame. 1460100100020 DETECTOR (TELES,SISD,SISD) Charged particles were detected 1460100100021 with a Si telescope located 19 mm downstream from the 1460100100022 target. Telescope consisted of two Micron S-2 type 1460100100023 anular Si detectors, 152 mu-m thick dE detector and 1460100100024 994 mu-m thick E detector, separated by 4 mm. 1460100100025 Both Si detectors were segmented into 48 0.5-mm-wide 1460100100026 rings on one side and 16 22.5deg wide sectors on 1460100100027 the other. Fission fragments were detected with a 1460100100028 third 146 mu-m thick Micron S2 silicon detector 1460100100029 located 19 mm upstream from the target. 1460100100030 (SCIN) Target and charged particle telescopes were 1460100100031 located inside neutron detector, consisting of a tank 1460100100032 filled with 3.5 t of liquid scintillator EJ-335, 1460100100033 doped with 0.25 wt% of natural gadolinium. Tank 1460100100034 was segmented into four identical quadrants, which 1460100100035 formed central cylindrical part of the detector and 1460100100036 two spherical endcups. Twenty photomultiplier tubes, 1460100100037 three on each quadrant and four on each endcup were 1460100100038 used to read out the neutron detector. In present 1460100100039 experiment only central part of the detector was 1460100100040 used. 1460100100041 METHOD (EDE) Charged particles p, d, t, 3He and alpha were 1460100100042 identified by E-dE method in forward Si telescope 1460100100043 (COINC) A 240Pu(a,a'f) reaction was identified by 1460100100044 a coincidence of alpha particle in forward telescope 1460100100045 and fission fragment in backward telescope. 1460100100046 ANALYSIS (SURGT) Surrogate method was used. For identified 1460100100047 240Pu(a,a'f) reactions a time window opened 50mu-s 1460100100048 before and closed 500 mu-s after the event was used 1460100100049 for neutron detection.The excitation energy of 240Pu 1460100100050 following inelastic alpha particle scattering was 1460100100051 determined from the beam energy,the scattered alpha 1460100100052 particle energy and the 240Pu recoil energy. 1460100100053 The equivalent incident neutron energy 1460100100054 was determined from calculated excitation energy. 1460100100055 ERR-ANALYS (DATA-ERR) Uncertainty is dominated by statistical 1460100100056 uncertainty in the number of coincidences and the 1460100100057 number of detected neutrons 1460100100058 HISTORY (20200113C) Compiled by S.H. 1460100100059 ENDBIB 57 0 1460100100060 NOCOMMON 0 0 1460100100061 ENDSUBENT 60 0 1460100199999 SUBENT 14601002 20200113 14631460100200001 BIB 2 2 1460100200002 REACTION (94-PU-239(N,F),PR,NU) 1460100200003 STATUS (TABLE) Data taken from tab. 2 of the reference 1460100200004 ENDBIB 2 0 1460100200005 NOCOMMON 0 0 1460100200006 DATA 3 51 1460100200007 EN DATA DATA-ERR 1460100200008 MEV PRT/FIS PRT/FIS 1460100200009 0.25 2.97 0.08 1460100200010 0.75 3.08 0.09 1460100200011 1.25 3.17 0.09 1460100200012 1.75 3.17 0.09 1460100200013 2.25 3.23 0.09 1460100200014 2.75 3.35 0.10 1460100200015 3.25 3.48 0.10 1460100200016 3.75 3.48 0.10 1460100200017 4.25 3.55 0.11 1460100200018 4.75 3.62 0.11 1460100200019 5.25 3.78 0.12 1460100200020 5.75 3.79 0.12 1460100200021 6.25 3.89 0.12 1460100200022 6.75 4.00 0.12 1460100200023 7.25 4.06 0.12 1460100200024 7.75 4.16 0.12 1460100200025 8.25 4.36 0.13 1460100200026 8.75 4.33 0.13 1460100200027 9.25 4.26 0.13 1460100200028 9.75 4.36 0.13 1460100200029 10.75 4.49 0.14 1460100200030 11.25 4.49 0.14 1460100200031 11.75 4.67 0.15 1460100200032 12.25 4.73 0.15 1460100200033 12.75 4.93 0.16 1460100200034 13.25 4.84 0.15 1460100200035 13.75 4.87 0.15 1460100200036 14.25 4.95 0.16 1460100200037 14.75 4.92 0.16 1460100200038 15.25 4.95 0.16 1460100200039 15.75 5.13 0.17 1460100200040 16.25 5.24 0.17 1460100200041 16.75 5.24 0.17 1460100200042 17.25 5.16 0.17 1460100200043 17.75 5.26 0.17 1460100200044 18.25 5.36 0.17 1460100200045 18.75 5.38 0.18 1460100200046 19.25 5.67 0.19 1460100200047 19.75 5.58 0.19 1460100200048 20.25 5.48 0.20 1460100200049 20.75 5.80 0.20 1460100200050 21.25 5.83 0.21 1460100200051 21.75 6.06 0.23 1460100200052 22.25 5.96 0.24 1460100200053 22.75 6.14 0.25 1460100200054 23.25 6.06 0.26 1460100200055 24.25 6.03 0.29 1460100200056 24.75 6.19 0.34 1460100200057 25.25 6.53 0.39 1460100200058 25.75 6.34 0.44 1460100200059 26.25 6.56 0.55 1460100200060 ENDDATA 53 0 1460100200061 ENDSUBENT 60 0 1460100299999 ENDENTRY 2 0 1460199999999