STUDY OF NEUTRON CROSS-SECTIONS AND THE α=σγ/σf VALUE FOR U-235 IN THE 1 meV-2 eV ENERGY RANGE

Authors & Affiliations

Grigoriev Yu.V.1, Sinitsa V.V.1, Borzakov S.B.2, Ilchev2 G.L., Fajkov-Stanchik H.2, Panteleev C.C.2, Yaneva N.B.3

1Russian Federation National Research Centre - Institute for Physics and Power Engineering, Obninsk, Russia
2Joint Institute for Nuclear Research (JINR), Dubna, Russia
3Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria

Abstract

The time-of-flight and amplitude spectra of low-energy capture gamma rays and prompt fission gamma rays were measured on the 34 m and 27 m time-of-flight bases of the IBR-2 at the Neutron Physics Laboratory of the JINR using HPGe and Ge(Li) detectors. The sample-radiator was a thin metal disk of 235U (90%) and 238U (10%), 0.25 mm thick and 48 mm in diameter. The alpha value was obtained from the amplitude spectra for 27 energy groups in the 1 meV-2 eV energy range, as the ratio of the measured gamma-rays yields per capture to fission events; this was normalized to the standard alpha value for the thermal neutron energy.

Keywords
time of flight, amplitude spectra, low energy capture gamma-rays and prompt fission gamma-rays, alpha value, gamma-rays per capture to fission events

Article Text (in English, PDF, Translated by IAEA)

References

UDC 621.039.51

Problems of Atomic Science and Technology. Series: Nuclear Constants, issue 1, 2000