Prompt fission gamma-ray emission spectral data for ²³⁹Pu(n,f) using fast directional neutrons from the LICORNE neutron source

Abstract

Abstract. Prompt fission gamma-ray spectra (PFGS) have been measured for the 239 Pu(n,f) reaction using fast neutrons atĒ n =1.81 MeV produced by the LICORNE directional neutron source. The setup makes use of LaBr 3 scintillation detectors and PARIS phoswich detectors to measure the emitted prompt fission gamma rays (PFG). The mean multiplicity, average total energy release per fission and average energy of photons are extracted from the unfolded PFGS. These new measurements provide complementary information to other recent work on thermal neutron induced fission of 239 Pu and spontaneous fission of 252 Cf.

Potential of prompt $$\gamma $$-ray emission studies in fast-neutron induced fission: a first step

“…The results for 239 Pu(n,f) at E n = 1.8 MeV are presented for the first time (with some preliminary data shown in Ref. [20]). Its PFGS is displayed in Fig.…”

“…The reaction p( 7 Li, n) 7 Be was used to generate a quasi-monoenergetic kinematically focused neutron beam of energy E n = 1.8 MeV. To select fission events, a specifically-designed fission chamber was constructed at JRC-Geel, containing the 239 Pu sample [18,20]. The purity and total mass of the 239 Pu sample was 99.97% and 3.519 mg, respectively.…”

“…Details and spectra have been reported in Ref. [20]. The total number of fission events collected amounts to 5.5 × 10 6 .…”

“…The aim of the present work is to contribute to the ongoing worldwide investigation by exploiting the results of a recent experimental campaign [18][19][20] on fast-neutron induced fission of 238 U and 239 Pu, including also spontaneous fission of 252 Cf, at the ALTO/LICORNE facility [21], IPN Orsay, France. The results for n+ 239 Pu are presented for the first time.…”

Prompt $$\gamma $$-ray characteristics from $$^{235}$$U(n, f) at $${\overline{E}}_{n}$$ = 1.7 MeV

“…[11] for thermal neutrons, Refs. [12,13] for E n = 1.8 MeV). However, one should take into account that the width of the chosen prompt window in the thermal-neutron induced fission on 235 U [9] and the fast-neutron induced fission on 238 U [4] (used for the normalization) is five and four times the coincidence timing resolution, respectively.…”