New data on prefission neutrons

Boikov, G. S.; Dmitriev, V. D.; Kudyaev, G.A.; Ostapenko, Yu. B.; Svirin, M. I.; Smirenkin, G.N.

doi:10.1007/bf01284483

Cited by 13 publications

(3 citation statements)

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“…Whilst prompt fission neutron emission is being studied during the last 50 years, see, e.g., refs. [1][2][3][4][5][6], prompt γ-ray emission was investigated essentially in the early 1970 years and only for a limited number of fissioning isotopes. From measured prompt fission γ-ray spectra (PFGS) average values for the total energy release per fission and γ-multiplicity were obtained.…”

Section: Introductionmentioning

confidence: 99%

Future research program on prompt $\gamma$ -ray emission in nuclear fission

et al. 2015

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Abstract. In recent years the measurement of prompt fission γ-ray spectra (PFGS) has gained renewed interest, after about forty years since the first comprehensive studies of the reactions 235 U(n th , f), 239 Pu(n th , f) and 252 Cf(sf). The renaissance was initiated by requests for new values especially for γ-ray multiplicity and average total energy release per fission in neutron-induced fission of 235 U and 239 Pu. Both isotopes are considered the most important ones with respect to the modeling of innovative cores required for the Generation-IV reactors, the majority working with fast neutrons. During the last 5 years we have conducted a systematic study of spectral data for thermal-neutron-induced fission on 235 U and 241 Pu as well as for the spontaneous fission of 252 Cf with unprecedented accuracy. From the new data we conclude that those reactions do not considerably contribute to the observed heat excess and suspect other reactions playing a significant role. Possible contributions may originate from fast-neutron-induced reactions on 238 U, which is largely present in the fuel, or from γ-induced fission from neutron capture in the construction material. A first experiment campaign on prompt γ-ray emission from fast-neutron-induced fission on 235,238 U was successfully performed in order to test our assumptions. In the following we attempt to summarize, what has been done in the field to date, and to motivate future measurement campaigns exploiting dedicated neutron and photon beams as well as upcoming highly efficient detector assemblies.

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Section: Introductionmentioning

confidence: 99%

Future research program on prompt $\gamma$ -ray emission in nuclear fission

et al. 2015

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“…Veeser, 21 and Fréhaut. 16 The evaluation of ν -(E n ) in JENDL-3.3 in addition considers Boikov 22 and Mughabghab. 23 The present formulas agree quite well with JENDL-3.3 evaluation.…”

Section: Verificationmentioning

confidence: 99%

Empirical Formulas for Estimation of Fission Prompt Neutron Multiplicity for Actinide Nuclides

Ohsawa¹

2008

Journal of Nuclear and Radiochemical Sciences

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“…The neutron energy ranges from zero to 15 MeV. The publications of Boikov et al [2] and Ethvigot et al [3] report such neutron spectrum measurements by using multi-layer ionization chambers containing thin deposits of fissile elements. The detection of a fission fragment was taken as an indication of a fission event and also as the time the fission event occurred.…”

Section: Introductionmentioning

confidence: 97%

Measurement of U-235 Fission Neutron Spectra Using a Multiple Gamma Coincidence Technique

Ji¹,

Kegel²,

Egan³

et al. 2005

AIP Conference Proceedings

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The Los Alamos Model of Madland and Nix predicts the shape of the fission neutron energy spectrum for incident primary neutrons of different energies. Verifications of the model normally are limited to measurements of the fission neutron spectra for energies higher than that of the primary neutrons because the low-energy spectrum is distorted by the admixture of elastically and inelastically scattered neutrons. This situation can be remedied by using a measuring technique that separates fission from scattering events. One solution consists of using a fissile sample so thin that fission fragments can be observed indicating the occurrence of a fission event. A different approach is considered in this paper. It has been established that a fission event is accompanied by the emission of between seven and eight gamma rays, while in a scattering interaction, between zero and two gammas are emitted, so that a gamma multiplicity detector should supply a datum to distinguish a fission event from a scattering event. We proceed as follows: A subnanosecond pulsed and bunched proton beam from the UML Van de Graaff generates nearly mono-energetic neutrons by irradiating a thin metallic lithium target. The neutrons irradiate a 235 U sample. Emerging neutron energies are measured with a time-of-flight spectrometer. A set of four BaF 2 detectors is located close to the 235 U sample. These detectors together with their electronic components identify five different events for each neutron detected, i.e., whether four, three, two, one, or none of the BaF 2 detectors received one (or more) gamma rays. We present work, preliminary to the final measurements, involving feasibility considerations based on gamma-ray coincidence measurements with four BaF 2 detectors, and the design of a Fission-Scattering Discriminator under construction.

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New data on prefission neutrons

Cited by 13 publications

References 10 publications

Future research program on prompt $\gamma$ -ray emission in nuclear fission

Future research program on prompt $\gamma$ -ray emission in nuclear fission

Empirical Formulas for Estimation of Fission Prompt Neutron Multiplicity for Actinide Nuclides

Measurement of U-235 Fission Neutron Spectra Using a Multiple Gamma Coincidence Technique

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