Contents

1 Introduction

KVedaLoss provides range tables for the stopping of charged ions in a variety of solid and gaseous media. It can be used to calculated energy losses, residual energies, ranges, and the corresponding inverse calculations. It is based on the original code VEDALOSS developed by R. Dayras and E. De Filippo for the INDRA collaboration [1]. This code interpolates the range tables of Northcliffe and Schilling [2] with those of Hubert, Bimbot and Gauvin [3] in order to calculate ranges based on data valid in the energy range 0.1 ≤ E∕A ≤ 250 MeV. For E∕A < 2.5 MeV ranges are taken from [2] (which include the contribution from nuclear stopping), while at higher energies ranges are taken from [3]. It should be noted that the ranges of [3] were calculated from 2.5 MeV/nucleon upwards, taking the Northcliffe and Schilling range at 2.5 MeV/nucleon as starting point.

2 Method

For each material, the interpolated range for each ion from Z = 1 to Z = 100 has been parametrised as

(1)

where R is the range [g∕cm²] of the ion and ϵ its incident energy [MeV /nucleon]. The six parameters a_i for each atomic number Z (for a reference isotope A) were found by fitting Eq. 1 to the range data taken from [2, 3]. Ranges for different isotopes, A′, can be calculated simply using the relation

(2)

The range function, Eq. 1, is implemented in the code using the ROOT class TF1. In order to invert the range function and obtain the incident energy corresponding to a given range, we use method TF1::GetX().

The energy loss ΔE of a charged ion of incident energy E in a thickness Δx of a given material is calculated using

(3)

where R^-1 is the inverse range function and ρ the density [g∕cm³] of the material. Again, this energy loss function is parametrised using ROOT::TF1, which allows to obtain incident energies from measured energy loss using TF1::GetX().

3 Comparison with tables

The following figures present comparisons between KVedaLoss and the original tables of [2, 3]. They are extracted from [6].

3.1 Solid materials

3.2 Gaseous materials

Ranges for gaseous materials were parametrised using a modified form of the ion effective charge energy dependence, using data from [4, 5]. Some comparisons between KVedaLoss and that data are presented here.

References