Although TRAX
scores the various particle interactions
and energy depositions on a volume-by-volume basis,
specific physical problems might require dedicated analysis.
To support this, a couple of evaluation procedures and associated
commands are provided
which read
listmode
data files and output evaluated results as ASCII data files
in
gd plotting format.
Depth dose profiles are 1-dimensional projections
of the dose distribution
generated by particles emitted from a point source in a fixed direction.
See the
evaladose command.
Crossers, starters, stoppers, insiders
This procedure is not yet fully implemented!
Its intended purpose is the
evaluation of the number of ionizations volume-by-volume as well as the
energy deposited by particles
- crossing the volume (crossers), i.e. starting and stopping
outside the volume under consideration
- starting within the volume (starters), i.e. stopping
somewhere else,
- stopping within the volume (stoppers), i.e. starting
somewhere else,
- starting and stopping within a volume (insiders)
See the
evalcrossers command.
Microdosimetric distributions
These are specific energy, z, and lineal energy deposition,
y, calculated as a function of the radial distance from the
primary ion path. Both depend on the size (diameter) of the sensitive
volume as well as on its shape (cylinder, sphere).
Additionally, sort of an "inactivation" cross section
is calculated assuming a threshold (minimum number of ionizations)
for lethal damage.
See the
evalmdose command.
Emission spectra
These are single differential energy and angular distributions,
as well as double differential energy distributions with the angle
as a parameter.
The spectra are build from the energy and flight direction of
particles leaving a volume, e.g. a thin foil.
See the
evalout command.
Radial dose distribution
This is a 1-dimensional dose distribution assuming cylindrical
symmetry around an ion path, averaged along the z-axis.
It is obtained as an ionization as well
as an energy deposition distribution. The first one is closer to
most experiments since they "see" only ionizations,
not excitations. The calculated ionization dose, however,
needs to be multiplied with a global W-value (in keV) to be comparable with
experiments (which measure in Gy).
See the
evalrdose command.
Cylindrical (r-z) dose distributions
This is a 2-dimensional dose distribution assuming cylindrical
symmetry around an ion path. It is obtained as an ionization as well
as an energy deposition distribution. The first one is closer to
most experiments since they "see" only ionizations,
not excitations. The calculated ionization dose, however,
needs to be multiplied with a global W-value (in keV) to be comparable with
experiments (which measure in Gy).
See the
evalrzdose command.
Spherical dose distributions
This is a 1-dimensional dose distribution assuming spherical
symmetry around a point source, averaged along the polar and azimuth angles.
It is obtained as an ionization as well
as an energy deposition distribution. The first one is closer to
most experiments since they "see" only ionizations,
not excitations. The calculated ionization dose, however,
needs to be multiplied with a global W-value (in keV) to be comparable with
experiments (which measure in Gy).
See the
evalsphere command.
Time-energy spectra
For this evaluation electron energy spectra are taken corresponding
to specified intervals of time-of-flight of the electrons.
Should give some info on the time evolution.
However, I don't know if the information is reasonable (i.e. it has never been verified
against experiments) nor do I know if it's useful at all.
See the
evaltespec command.
Volume specific energy spectra
For each volume the energy deposition spectra are generated
(volume mode).
This corresponds more to a classical detector simulation.
See the
evalvolespc command.
Line track pictures
These are the well-known "track" pictures.
They are derived in a multi-pass evaluation from listmode data
necessarily resident on some file.
Output are the flight paths of electrons, coloured according to
their residual energy.
See the
linetrack command.
Point track pictures
With these pictures
tracks are represented as symbols for the points of
interactions. Different symbols are used for the different types
of interactions, as described in the gd header lines.
Different colours are used for the different
particle types:
- e-: blue,
- e+: red (not yet implemented),
- x: black (not yet implemented),
- n: yellow (not yet implemented),
- ions: green.
Additionally the local energy deposition is written as an additional
column, which might be used as a varying symbol size.
See the
pointtrack command.
Radical Evaluation
This is the way TRAX
currently handles radiation chemistry.
Physics events such as ionization, excitation and cutoff produce
chemical species (radicals and ions) by dissociation of the struck target
molecules.
These species are collected in a separate internal table until the end of the
physics simulation.
On end-of-run they are
followed up by a separate chemical simulation comprising diffusion and reaction.
The chemical simulation eventually yields G-values over time,
species track snapshots and species radial distributions.
See the
evalrcal command.
User Specific Evaluation
In addition to the builtin hardcoded evaluation functions,
a mechanism is provided for user supplied evaluation functions.
These require an external C function coded, compiled and linked according to
TRAX
standards.
See the
evalusr command.
Last updated: M.Kraemer
$Id: traxeval.html,v 1.7 2019/03/17 22:57:50 kraemer Exp $