stopping.power.source: Sources of stopping power data
Description
Three stopping power data sources are implemented in libamtrack.
They are referred to using keywords or integer identifiers (see below). In
addition, the user can provide a filename point to custom data in text
format. The built-in sources provide electronic mass stopping power as a
function of specific energy (details see below).
Scaling with density (or use of material parameters by Bethe formular) is done
using the material specified. In case of custom stopping power data, the user
has either to make sure that the right data (i.e. electronic mass stopping
power) are provided with the correct units (E/u and MeV*cm2/g) OR use any
kind of data / units if they know what they are doing...
(material.no = 0).
Built-in data are given in specific energy per amu for the most frequent
isotope (i.e. H-1, He-4 etc.) or directly in specific energy per nucleon
(i.e. in case of the Bethe formula). Scaling to other isotopes happens via
the number of nucleons. Thus, effects of changes in binding energy per
nucleon are neglected. These are usually small (0.7 important for high-accuracy application. The same is true for the material
parameters, e.g. the I-value. In that case, it is adviced to use external
tabulated data.
These tabulated data have to be plain ASCII with three columns (separated by
space): charge, energy, and stopping power. The datahave to be sorted in
ascending order by first charge than energy. In addition, any alphanumeric
comment can be inserted (in separate lines).
Stopping power data handling underwent a major rework in v0.6.0 and
identifiers were changed. To avoid confusion, downward compatibility might be
not maintained and integer identifiers depreceated.Details
The stopping power sources are:
rcl{
stopping.power.source.no stopping.power.source description
--- data are read from external file (see details)
1 Bethe Analytical Bethe formular, including density effect, for
any material, if composition is given.
2 PSTAR Tabulated data from NIST's PSTAR code, for other ions
scales by the square of the effective charge. CAVE: Scaling by E/n!
3 ICRU Tabulated data from ICRU49 (H, He) and ICRU73, for liquid
water only. N.B. the I value inconsistency between the two reports
--- libdEdx_SOURCE Reserved keyword for later use with libdEdx and
data source SOURCE
}See Also
More information, especially the explicit formulas used, valid energy
ranges and references to literature are found in the libamtrack reference
manual
(http://libamtrack.dkfz.org/libamtrack/images/3/31/LibamtrackReferenceMa
nual.pdf).