Eur. Phys. J. A (2013) 49: 51
https://doi.org/10.1140/epja/i2013-13051-6

Regular Article - Experimental Physics

Mass dependence of azimuthal asymmetry in the fission of ²³²Th and ^{233,235,236,238}U by polarized photons

¹⁹⁸⁸¹ National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine
²⁹⁸⁸¹ Federal University of Technology - Paraná, Curitiba, Brazil
³⁹⁸⁸¹ Pelé Pequeno Príncipe Research Institute, Curitiba, Brazil

^* e-mail: denyak@gmail.com

Received: 7 January 2013
Revised: 15 March 2013
Accepted: 29 March 2013
Published online: 25 April 2013

Abstract

Fission of the even-even nuclei ²³²Th, ^236,238U and even-odd nuclei ^233,235U by linearly polarized photons has been studied at excitation energies in the region of a giant dipole resonance. The performed investigations unambiguously showed the existence of the fragment mass dependence of the cross section azimuthal asymmetry in the photofission of ²³⁶U and ²³⁸U. In addition, the obtained results provided the first evidence for the possible difference between the asymmetry values in asymmetric and symmetric mass distribution regions in the case of ²³⁶U. The measured cross section azimuthal asymmetry of the fission of ²³²Th does not show any fragment mass dependence. In the even-odd nuclei ²³³U and ²³⁵U the difference between the far-asymmetric and other mass distribution regions was also observed but with the statistical uncertainty not small enough for definitive conclusion.