Measurement of differential (n,x{alpha}) cross section using 4{pi} gridded ionization chamber Sanami, Toshiya; Baba, Mamoru; Matsuyama, Shigeo; Kiyosumi, Takehide; Nauchi, Yasushi; Saito, Keiichiro; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan). Faculty of Engineering]; Kawano, Toshihiko 66 PHYSICS; NICKEL 58 TARGET; NEUTRON REACTIONS; ALPHA SPECTRA; DIFFERENTIAL CROSS SECTIONS; CARBON 12 TARGET; EXCITATION FUNCTIONS; MULTIWIRE IONIZATION CHAMBERS; ANGULAR DISTRIBUTION; MEV RANGE 01-10; MEV RANGE 10-100 We carried out the measurements of high resolution {alpha} emission spectra of {sup 58}Ni and {sup nat}Ni between 4.5 and 6.5 MeV, and {sup 12}C(n,x{alpha}) cross section using a 4{pi} gridded ionization chamber. In Ni measurement, overall energy resolution was improved to around 200 keV by optimizing a sample thickness and a neutron source width. Measured alpha spectra showed separate peaks corresponding to the ground and low-lying excited states of the residual nucleus ({sup 55}Fe). These results were compared with another direct measurement and statistical model calculations. In {sup 12}C measurement, GIC was applied for (n,x{alpha}) reactions of light nuclei. This application is difficult to (n,x{alpha}) cross sections of light nuclei, because of the influences of large recoil energy and multi-body break-up. We developed new methods which eliminate the effects of recoil nuclei and multi-body break-up and applied them to {sup 12}C(n,x{alpha}) reaction at En=14.1 MeV. In our experiment, the {sup 12}C(n,{alpha}{sub 0}){sup 9}Be angular differential cross section and {sup 12}C(n,n`3{alpha}) cross section were obtained. (author) Japan Atomic Energy Research Inst., Tokyo (Japan) OSTI as DE97758661 Japan 1997-03-01 English Conference Conference: ISND-1: 1. internet symposium on nuclear data, Tokai (Japan), 8 Apr - 15 Jun 1996; Other Information: PBD: Mar 1997; Related Information: Is Part Of Proceedings of the first internet symposium on nuclear data; Fukahori, Tokio; Iwamoto, Osamu; Nakagawa, Tsuneo [eds.] [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment]; PB: 285 p. Medium: ED; Size: pp. 225-233 https://doi.org/ ON: DE97758661 [] JAERI-Conf-97-004; CONF-9604220-; INDC(JPN)-178/U Other: ON: DE97758661; TRN: JP9708208 JPN; SCA: 663430; PA: JPN-97:008208; EDB-97:134336; SN: 97001850460 2018-05-18 530415 https://www.osti.gov/etdeweb/servlets/purl/530415