Multi-pronged events from Coulomb fission of nuclei at very low energies

TL;DR

This study observes multi-pronged tracks in nuclear track detectors exposed to a Californium-252 source, attributing their origin to Coulomb fission at very low energies around 1 MeV/A.

Contribution

It provides experimental evidence linking multi-pronged tracks to Coulomb fission at low energies, supported by systematic observations with metal-coated detectors.

Findings

Multi-pronged tracks observed in solid state nuclear track detectors.

Coulomb fission identified as the likely cause of multi-pronged tracks at low energies.

Metal coating influences track morphology.

Abstract

Multi-pronged tracks have been recorded in the polyethylene terephthalate (C$_{10}$H$_8$O$_4$)$_n$ solid state nuclear track detector by exposure to a $^{252}$Cf fission source. After chemical etching, two-prong to six-pronged tracks along with single tracks have been observed under the optical microscope. We carried out a systematic study to understand the origin of the prongs. The track detectors were coated with metals (Cu, Ag and Pb) and were exposed to $^{252}$Cf source. After chemical etching two-prong to four pronged tracks were observed in each plate. We believe that at this very low energy of the order of 1 MeV/A, Coulomb fission is the only plausible explanation for the origin of such multi-pronged tracks.