Eur. Phys. J. A (2011) 47: 9
https://doi.org/10.1140/epja/i2011-11009-4

Regular Article - Experimental Physics

Nuclear-charge polarization at scission in proton-induced fission of ²³³U

¹ Japan Atomic Energy Agency, 319-1195, Tokai-mura, Naka-gun, Ibaraki, Japan
² School of Science, University of Tokyo, 113-0033, Hongo, Bunkyo-ku, Tokyo, Japan
³ Tokyo Metropolitan University, 192-0397, Minami-Ohsawa, Hachioji, Tokyo, Japan

^* e-mail: nishinaka.ichiro@jaea.go.jp

Received: 10 August 2010
Revised: 22 November 2010
Accepted: 30 November 2010
Published online: 7 January 2011

Abstract

The primary and the secondary fragment mass yields and neutron multiplicity in the 11.5MeV proton-induced fission of ²³³U were determined by a double time-of-flight method. The most probable charges of the secondary fragments in the isobaric chains with A = 126 , 127, 129, 132, and 136 have been derived from the secondary mass yields together with the literature values of the fractional cumulative and independent yields measured radiochemically. The nuclear-charge polarization of primary fragments at scission was obtained by correcting the secondary fragment mass for neutron evaporation. The results show that the nuclear-charge polarization is mostly determined by the minimum potential energy of nuclei at scission and that this behavior is nearly independent not only of mass and excitation energy but also of neutron-to-proton ratios of the fissioning nuclei.