Surface Ionization of Radioactive Nuclides - Numerical Simulations

Abstract

The Monte Carlo method based model of the ionization in the hot cavity taking into account radioactive decay of nuclides is presented. The code upgraded compared to the previous version enables calculation of the ion source ionization eciency not only for dierent geometries and temperatures of the ionizer, extraction voltages etc. but also gives opportunity of setting dierent values of the nuclide half-life and its sticking time, which may be considered as the main factor determining the time that a particle spends in the ion source. The results of calculations are presented together with the discussion of the radioactive decay on the ion source performance.

Calculations of Ion Beam Emittance for Hot Cavity Ion Source

“…Recently, a numerical model of ionization in hot cavity ion source has been developed [12,16,17], taking into account not only surface ionization but also possible eects of electron impact ionization mechanism [18]. Initially the model was suitable for stable and long-lived isotopes, but radioactive decay and delays due to the diusion and eusion were implemented [12,19], making it useful also for short-lived isotopes, which are common in on-line nuclear spectroscopy. Mainly tubular cavities were considered, but the model was extended to spherical cavities [20], which are employed in experiments [21,22].…”

Two-Dimensional Simulations of H-Ions Extraction

“…This is done using the successive over-relaxation method as in papers [16,17,[26][27][28][29][30]. Electric field is calculated by numerical derivation of the potential.…”

Ionization of Short-Lived Isotopes in Spherical Hot Cavities

“…Numerical model of ionization is similar to that described in [20,21,2325] where mainly tubular ionizers were considered. In the paper spherical ionizers are under investigation.…”

“…In the previous papers [20,21] the ionization of shortlived isotopes mostly in tubular ionizers was considered. Ionization of stable nuclides in spherical cavities was also studied.…”