Eur. Phys. J. A (2014) 50: 144
https://doi.org/10.1140/epja/i2014-14144-4

Regular Article - Experimental Physics

Mass distribution in the quasi-mono-energetic neutron-induced fission of ²³²Th

¹ Radiochemistry Division, Bhabha Atomic Research Centre, 400 085, Mumbai, India
² Microtron Centre, Department of Studies in Physics, Mangalore University, Karnataka, India
³ Nuclear Physics Division, Bhabha Atomic Research Centre, 400 085, Mumbai, India
⁴ Physics Department, Faculty of Science, The M. S. University of Baroda, 390 002, Vadodara, India
⁵ Department of Physics, University of Pune, 411 007, Pune, India
⁶ Department of Statistics, Manipal University, 576 104, Manipal, India
⁷ Radiopharmaceutical Division, Bhabha Atomic Research Centre, 400 085, Mumbai, India

^* e-mail: naikhbarc@yahoo.com

Received: 29 June 2014
Revised: 10 August 2014
Accepted: 14 August 2014
Published online: 19 September 2014

Abstract

The cumulative yields of various fission products in ²³²Th(n, f) with average neutron energies of 6.35, 8.53 and 10.09 MeV have been determined using an off-line -ray spectrometric technique. The neutron beam was produced from the ⁷Li(p, n) reaction. From the cumulative fission yields, the mass chain yields were obtained by using charge distribution correction of medium energy. The peak-to-valley () ratio, the average value of light mass (), heavy mass () and the average number of neutrons () at the three different neutron energies of the present work and at other energies from the literature in the ²³²Th(n, f) reaction were obtained from the mass yield data. The present and the existing literature data in the ²³²Th(n, f) reaction at various excitation energies were compared with similar data in the ²³⁸U(n, f) reaction. The fine structure in the mass yield distribution was interpreted from the point of nuclear structure effect such as shell closure proximity and even-odd effect. The role of standard I and standard II asymmetric mode of fission was discussed. The different types of mass-yield distributions between ²³²Th(n, f) and ²³⁸U(n, f) reactions were explained from different types of the potential energy between the two fissioning systems. The role of excitation energy was also investigated.