Measurement of high-energy prompt -rays from neutron induced fission of U-235

Makii, Hiroyuki   ; Nishio, Katsuhisa   ; Hirose, Kentaro  ; Orlandi, R.  ; Lguillon, R.; Ogawa, Tatsuhiko   ; Soldner, T.*; Hambsch, F.-J.*; Astier, A.*; Pollitt, A.*; Petrache, C. M.*; Tsekhanovich, I.*; Mathieu, L.*; Ache, M.*; Frost, R.*; Czajkowski, S.*; Guo, S.*; Kster, U.*

The measurement of the prompt fission -ray spectrum (PFGS) is quite important to study the de-excitation process of neutron-rich fission fragments as well as to generate data required to design a generation-IV reactors. The PFGS measured for spontaneous fission of Cf shows a broad hump at energies more than 8 MeV. This is interpreted as a giant dipole resonance (GDR) of the fragments centered around 15 MeV. To understand how the GDR is populated in the fission process, one needs to measure the PFGS for the reactions with the mass yields different from the spontaneous fission of Cf, such as (n,f). The measurements of the PFGS for (n,f), however, are limited less than 9 MeV even in the recent experiment. This prompts us to make a new measurement to extend the know PFGS up to 20 MeV. The measurement has been carried out at the PF1B beam line of Institut Laue-Langevin. In this contribution we will present the results obtained the measurement.