Nuclear charge distribution in the spontaneous fission of 252Cf

TL;DR

This study measures charge distributions in the spontaneous fission of 252Cf, revealing systematic trends related to fragment mass, energy, and odd-even effects, using a novel detector setup.

Contribution

It introduces a unique detector setup to measure charge distributions in 252Cf fission and analyzes their dependence on fragment mass and energy.

Findings

Charge distribution width decreases with fragment mass, showing odd-even effects.

Charge variation with energy exhibits an approximate V-shape curve.

Average nuclear charge correlates linearly with primary mass number.

Abstract

The measurement for charge distributions of fragments in 252Cf has been performed by using a unique style of detector setup consisting of a typical grid ionization chamber and a dE-E particle telescope. We found that the fragment mass dependency of the average width of the charge distribution shows a systematic decreased trend with the obvious odd-even effect. The variation of widths of charge distribution with kinetic energies shows an approximate V-shape curve due to the large number of neutron emission for the high excitation energies and cold fragmentation with low excitation energies. As for the behavior of the average nuclear charge with respect to its deviation {\Delta}Z from the unchanged charge distribution (UCD) as a function of the mass number of primary fragments A*, for asymmetric fission products {\Delta}Z is negative value, while upon approaching mass symmetry {\Delta}Z turns positive. Concerning the energy dependence of the most probable charge for given primary mass number A*, the obvious increasing tendencies for with the kinetic energies are observed. The correlation between the average nuclear charge and the primary mass number is given as linear function. The proton and neutron odd-even effects with light fragment kinetic energies are derived.