PRODUCT YIELDS FOR THE PHOTOFISSION OF 238U, 237Np AND 239Pu


Akira Yamadera, Takeshi Kase and Takashi Nakamura

Cyclotron and Radioisotope Center, Tohoku University
Aramaki, Sendai-shi, Miyagi 980, Japan


Sheiichi Shibata

Institute for Nuclear Study, University of Tokyo
Midori-cho 3-2-1 Tanashi-shi, Tokyo 188, Japan


This paper shows the absolute yields for the mass distribution of photofission products of 238U, 237Np and 239Pu. The thin targets of 238U, 237Np and 239Pu were irradiated with the bremsstrahlung beam whose end-point energy was 20-, 30- and 60-MeV. Fission fragments recoiled out from the target were catched on the aluminum foil. The mass-yield distributions of fission fragments were obtained by measuring gamma-ray activities with a pure-Ge detector. Our mass distribution curves showed good agreement with the other experimental results.

KEYWORDS: photofission, cross section, bremsstrahlung, mass distribution, 238U, 237Np, 239Pu