SCENA: A simulation tool for radiation-induced gas scintillation

Abstract

Within the framework of the dependable neutron ux instrumentation development for Sodium-cooled Fast Reactor (SFR) of Generation IV, the French Alternative Energies and Atomic Energy Commission (CEA) is investigating an innovative technology based on optical signals produced within an ionization chamber. In such gaseous detectors, neutrons interact with a ssile material, releasing heavy ions in the MeV-range, eventually leading to spontaneous photon emission in the ultraviolet to infrared range. In this paper, the process of light generation is analyzed through a newly-developed computer code named SCENA. Semi-empirical models for ion-to-gas energy exchange and secondary electron production are assessed. The output of the SCENA subroutines are satisfactory checked against other electron swarm simulation tools, experimental data and a theoretical gas model. SCENA is able to follow the cold-plasma created along a heavy ion slowing-down in space and time evolution. This performance is a key point in the development of optical ionization chambers.

Simulation of heavy-ion slowing-down tracks with the SCENA code

“…We chose, as Budnik et al [15] to study individual slowing down tracks mechanisms along a space and time evolution in an attempt to build future radiationplasma macro-model, considering the plasma as an assembly of independent ionization tracks. Population states of this problem is achieved by a Monte-Carlo solved particle transport computer code developed previously, the Simulation of Collisions Electrons-Neutrals in Atmospheres (SCENA) [4]. SCENA allows a 3dimensions and time coupled analysis of both projectile ions and delta-electrons interactions with a monoatomic buer gas, as found in ssion chambers.…”

“…This paper starts with a historical review of radiation-induced cold-plasma simulations, their hypothesis and limitations. SCENA, our self-developed ssioninduced plasma simulation code [4] is briey described. A comparison between previous analytical work and SCENA set with similar hypothesis is assessed.…”