Understand the thermometry of hot nuclei from the energy spectra of light charged particles

TL;DR

This study assesses how accurately the temperature of hot nuclei can be measured using light charged particle spectra, considering experimental and theoretical factors, and identifies conditions for reliable measurements.

Contribution

It demonstrates that with ideal detection and conditions, the apparent temperature can be determined within 10% accuracy, improving understanding of nuclear thermometry.

Findings

Temperature determination accuracy is about 10% under ideal conditions.

Deuterons and tritons are the most reliable particles for temperature measurement.

Detection imperfections can significantly impair temperature measurements.

Abstract

In the domain of Fermi energy, the hot nucleus temperature can be determined by using the energy spectra of evaporated light charged particles. But this method of measurement is not without difficulties both theoretical and experimental. The presented study aims to disentangle the respective influences of different factors on the quality of this measurement : the physics, the detection (a 4? detector array as INDRA) and the experimental procedure. This analysis demonstrates the possibility of determining from an energy spectrum, with an accuracy of about 10 %, the true apparent temperature felt by a given type of particle emitted by a hot nucleus. Three conditions are however necessary : have a perfect detector of particles, an important statistics and very few secondary emissions. According to the GEMINI event generator, for hot nuclei of intermediate mass, only deuterons and tritons could fill these conditions. This temperature can allow to trace back to the initial temperature by using an appropriate method. This determination may be better than 15 %. With a real experimental device, an insufficient angular resolution and topological distortions caused by the detection can damage spectra to the point to make very difficult a correct determination of the apparent temperature. The experimental reconstruction of the frame of the hot nucleus may also be responsible for this deterioration