ENTRY 22731 20151009 22452273100000001 SUBENT 22731001 20151009 22452273100100001 BIB 14 67 2273100100002 TITLE Measurement of fission cross-section of neptunium-237 2273100100003 in resonance region with Electron Linac-driven Lead 2273100100004 Spectrometer. 2273100100005 AUTHOR (A.Yamanaka, I.Kimura, S.Kanazawa, K.Kobayashi, 2273100100006 S.Yamamoto, Y.Nakagome, Y.Fujita, T.Tamai) 2273100100007 INSTITUTE (2JPNKTO) Yamanaka, Kimura, Kinazawa - Departament 2273100100008 of Nuclear Engineering . 2273100100009 Katsuhei Kobayashi, Yamamoto, Nakagome, Fujita, 2273100100010 Tamai - Research Reactor Institute. 2273100100011 REFERENCE (J,NST,30,863,1993) Main reference 2273100100012 REL-REF (I,,A.Yamanaka+,S,JAERI-M-92-027,375,1992) 2273100100013 Experimental details 2273100100014 FACILITY (LINAC,2JPNKTO) Electron linear accelerator in pulsed 2273100100015 mode. Pulse repetition rate 180 pps, pulse width 2273100100016 33 nanosec, peak neutron current 2 A, accelerating 2273100100017 energy 32 MeV, average neutron yield = 1.0E+11 n/s 2273100100018 INC-SOURCE (PHOTO) Pb(gamma,n) reaction. Lead slowing-down 2273100100019 spectrometer of the Kyoto University research reactor 2273100100020 institute. The size and weight of this lead 2273100100021 spectrometer are 1.5 m cubic and about 38 t, 2273100100022 respectively. An air cooled photoneutron source which 2273100100023 consists of 12 Ta-discs is placed at its center. 2273100100024 DETECTOR (BF3,PROPC) For the slowing-down characteristics of 2273100100025 the lead spectrometer. 2273100100026 (IOCH) Back-to-back type double fission chambers for 2273100100027 measured the fission cross section of Np-237 relative 2273100100028 to that of U-235. The chambers were made of Al and 2273100100029 filled with a mixed gas of 97% Ar and 3% N(2) at 2273100100030 pressure of 1-atm. 2273100100031 (SIBAR) The number of atoms in the sample deposit and 2273100100032 that in the reference one together with those of 2273100100033 impurities were determined by the alpha-spectrometry 2273100100034 with a Si-surface barrier detector in vacuum. 2273100100035 INC-SPECT .Neutron spectrum was modified with the help of the 2273100100036 resonance filters In, Ta, Au, Ag, Mo, Co, Mn. 2273100100037 *EN-RSL* the energy resolution at 27.5-eV is 2273100100038 39+-1%, i.e. 11 eV 2273100100039 PART-DET (FF) 2273100100040 METHOD (SLODT) Slowing-down time 2273100100041 (STTA) Stack target irradiation using back-to-back 2273100100042 fission chambers 2273100100043 SAMPLE Neptunium oxide Np-O2 of about 2 mg weight with high 2273100100044 purity was electrodeposited on a stainless steel plate2273100100045 28-mm in diameter and 0.2-mm thick. The diameter of 2273100100046 the deposit was 2-cm. Number of Np237 atoms is 2273100100047 (1.99 +- 0.02)E+17, thickness 25 microgram/cm2. 2273100100048 Pu-238 admixture was 0.320+-0.003 ppm, 2273100100049 Pu-239 admixture was 1.10 +-0.13 ppm, 2273100100050 Uranium-235 monitor sample, highly enriched uranium 2273100100051 oxide, purity 99.91%, electrodeposited in the same 2273100100052 way as Np-237. After the electrodeposition, each plate2273100100053 was sintered with gas burner, and the reference 2273100100054 deposit became U3-O8. Number of U-235 in the sample 2273100100055 is (4.12 +- 0.09)E+17, Thickness is 50 microgram/cm2 2273100100056 ERR-ANALYS (ERR-T) The uncertainty is reported by authors in 2273100100057 table, in which: 2273100100058 * the statistical error for the fission, 2273100100059 * the error in the determination of the numbers of 2273100100060 Np-237 and U-235, 2273100100061 (ERR-SYS) 2% as systematic error and 2273100100062 * the uncertainty in the fission cross section for 2273100100063 U-235 were taken into account. 2273100100064 HISTORY (20060111C) S.M. 2273100100065 (20060210U) Last corrections have been done. 2273100100066 (20151009A) SD: SF8=SDT to REACTION code in Subent 002.2273100100067 Ref. on report moved to REL-REF and 2273100100068 corrected: JAERI-M-92 -> JAERI-M-92-027. 2273100100069 ENDBIB 67 0 2273100100070 COMMON 1 3 2273100100071 ERR-SYS 2273100100072 PER-CENT 2273100100073 2.0 2273100100074 ENDCOMMON 3 0 2273100100075 ENDSUBENT 74 0 2273100199999 SUBENT 22731002 20151009 22452273100200001 BIB 7 11 2273100200002 REACTION (93-NP-237(N,F),,SIG,,SDT) 2273100200003 ANALYSIS The cross section for the Np-237(n,f) reaction from 2273100200004 about 1 eV to about 5-keV normalized to that for the 2273100200005 U-235(n,f) reaction. 2273100200006 CORRECTION .Corrections were made for setting position of Np-237 2273100200007 and U-235 deposits. The loss of fission fragments in 2273100200008 the both deposited was found to be negligible. 2273100200009 MONITOR (92-U-235(N,F),,SIG) 2273100200010 MONIT-REF (,R.F.Rose,R,BNL-NCS-17541,1991) ENDF/B-VI 2273100200011 STATUS (TABLE) .Table 1 in NST,30,863,1993 2273100200012 HISTORY (20151009A) SD: SF8=SDT to REACTION code. 2273100200013 ENDBIB 11 0 2273100200014 COMMON 2 3 2273100200015 EN-NRM-MIN EN-NRM-MAX 2273100200016 EV EV 2273100200017 1. 5000. 2273100200018 ENDCOMMON 3 0 2273100200019 DATA 4 74 2273100200020 EN EN-RSL DATA ERR-T 2273100200021 EV EV MB MB 2273100200022 1.05 35.6 5.3 2273100200023 1.17 35. 5.1 2273100200024 1.32 32.6 4.4 2273100200025 1.48 21. 3.1 2273100200026 1.66 15.5 2.4 2273100200027 1.86 10.6 1.9 2273100200028 2.08 13.1 2.2 2273100200029 2.34 10. 2.2 2273100200030 2.62 11.7 2.3 2273100200031 2.94 13.7 2.5 2273100200032 3.3 19.6 3. 2273100200033 3.7 19.3 2.9 2273100200034 4.16 25. 3.3 2273100200035 4.66 38.2 4.7 2273100200036 5.23 50.7 5.7 2273100200037 5.87 51.8 5.7 2273100200038 6.58 48.4 5.5 2273100200039 7.39 45.3 5. 2273100200040 8.29 36. 4.1 2273100200041 9.3 31.2 3.5 2273100200042 10.4 25.8 3.1 2273100200043 11.7 24. 2.9 2273100200044 13.1 22.2 2.8 2273100200045 14.7 20. 2.4 2273100200046 16.5 24.7 2.6 2273100200047 18.5 44.5 3.8 2273100200048 20.8 87. 5.9 2273100200049 23.3 159.4 9.1 2273100200050 26.2 11. 270. 14. 2273100200051 29.4 432. 21. 2273100200052 32.9 618. 30. 2273100200053 37. 680. 33. 2273100200054 41.5 530. 26. 2273100200055 46.5 326. 17. 2273100200056 52.2 196. 11. 2273100200057 58.5 116.7 6.7 2273100200058 65.7 80. 4.9 2273100200059 73.7 61.9 3.9 2273100200060 82.7 68.1 4.2 2273100200061 92.7 88.3 5.1 2273100200062 104. 98.7 5.6 2273100200063 117. 95.6 5.4 2273100200064 131. 91.3 5.2 2273100200065 147. 114. 6.2 2273100200066 165. 148. 7.7 2273100200067 185. 152. 7.9 2273100200068 207. 134. 7.1 2273100200069 233. 112. 6. 2273100200070 261. 97.9 5.3 2273100200071 293. 88.7 4.9 2273100200072 329. 77.4 3.9 2273100200073 369. 64. 3.3 2273100200074 413. 54.5 2.9 2273100200075 464. 51.4 2.9 2273100200076 520. 49.9 2.9 2273100200077 584. 51.8 3.1 2273100200078 655. 48.1 3. 2273100200079 735. 55.3 3.5 2273100200080 824. 55.9 3.6 2273100200081 925. 52.5 3.6 2273100200082 1040. 53.7 3.8 2273100200083 1160. 44. 3.1 2273100200084 1310. 39.8 2.8 2273100200085 1470. 38.4 2.6 2273100200086 1640. 31.4 2.1 2273100200087 1840. 37.6 2.5 2273100200088 2070. 39.2 2.6 2273100200089 2320. 31.4 2.1 2273100200090 2600. 34. 2.2 2273100200091 2920. 32.4 3.1 2273100200092 3280. 29.7 1.9 2273100200093 3680. 27.7 1.7 2273100200094 4120. 32.6 2. 2273100200095 4630. 37.9 2.3 2273100200096 ENDDATA 76 0 2273100200097 ENDSUBENT 96 0 2273100299999 ENDENTRY 2 0 2273199999999