Authors & Affiliations
Vorobyev A.S., Shcherbakov O.A.
B.P Konstantinov Petersburg Nuclear Physics Insitute, NRC “Kurchatov Institute”, Gatchina, Russia
Shcherbakov O.A. - Senior Researcher, Dr. Sci.(Phys.-Math.) NRC “Kurchatov Institute” B.P Konstantinov Petersburg Nuclear Physics Insitute.
The prompt fission neutron spectra from thermal neutron - induced fission of 233U, 239Pu and spontaneous fission of 252Cf have been measured under the equal experimental conditions at the PNPI research reactor (Gatchina). During the measurements, the identity of the experimental geometry and subsequent analysis of the data obtained for these two investigated nuclei was guaranteed by the construction of the experimental set-up and data processing procedure. The measurements were performed simultaneously for the 11 values of angle between neutron emission direction and the light fission fragment direction of motion. To select fission fragment direction, the multi-wire proportional counters were used. The prompt fission neutron energy was obtained by the time-of-flight method. The pulse shape analysis was additionally used for separation of neutron and γ-quanta events. As a result of the data analysis performed, the ratios of the total prompt fission neutron spectrum of 233U(n,f) and 239Pu(n,f) to the total prompt fission neutron spectrum of 252Cf(sf) have been obtained. The obtained ratios have a weak dependence on the features of the experimental set-up and are free from errors inherent to absolute measurements. By using these ratios, the total prompt fission neutron spectra of 235U(n,f) and 239Pu(n,f) were calculated using the total prompt fission neutron spectrum of 252Cf(sf) recommended as an international standard for neutron spectra measurement.
nuclear fission, 235U, 239Pu, thermal neutrons, total prompt fission neutron spectra
1. Capote Noy R., Maslov V.M., Bauge E., Ohsawa T., Vorobyev A., Chadwick M.B., Oberstedt S., Consultants’ Meeting on Prompt Fission Neutron Spectra of Major Actinides. Report INDC(NDS)-0541. IAEA, Vienna, 2009.
2. Vorobyev A.S., Shcherbakov O.A., Pleva Yu.S., Gagarski A.M., Val’ski G.V., Petrov G.A., Petrova V.I., Zavarukhina T.A. Measurements of angular and energy distribution of prompt neutrons from thermal neutron-induced fission. Nuclear Instruments and Methods in Physics Research Section A, 2009, vol.598, no.3, pp.795-801. doi:10.1016/j.nima.2008.10.017
3. Vorobyev A.S., Shcherbakov O.A., Pleva Yu.S., Gagarski A.M., Val’ski G.V., Petrov G.A., Petrova V.I., Zavaruknina T.A. Angular and energy distributions of prompt neutrons from thermal neutron-induced fission of 233, 235U(n,f). Neutron Spectroscopy, Nuclear Structure, Related Topics. Proc. XVII Int. Sem. on Interaction of Neutrons with Nuclei, ISINN-17. Dubna, 2009.
4. Vorobyev A.S., Shcherbakov O.A. Integral''nyy spektr mgnovennykh neytronov pri delenii 235U teplovymi neytronami [Total prompt fission neutron spectrum from thermal-neutron-induced fission of 235U]. Voprosy atomnoy nauki i tekhniki. Seriya: Yadernye konstanty - Problems of atomic science and technology. Series: Nuclear Constants, 2011-2012, no.1-2, p. 37-54. Available at: http://vant.ippe.ru/images/pdf/2011-2012/4.pdf (accessed 27.04.2016).
5. Reich C.W., Mannhart W., England T. ENDF/B-VII.
6. Starostov B.I., Nefedov V.N., Boitsov A.A. Prompt fission neutron spectra from thermal neutron-induced fission of 233U, 235U, 239Pu and from spontaneous fission of 252Cf in energy range from 0.01 MeV to 12 MeV. Voprosy atomnoy nauki i tekhniki. Seriya:Yadernye konstanty - Problems of atomic science and technology. Series: Nuclear Constants, 1985, no.3, p. 16. EXFOR 40871013, 40872008 (for 233U) and 40871006, 40872003 (for 239Pu).
7. Lajtai A., Kecskemeti J., Safar J., Dyachenko P.P., Piksaikin V.M. IAEA-TECDOC-335 (1985) 312. EXFOR 30704002 (for 233U) and 30704004 (for 239Pu).