.geo.
Examples for a
radial dose calculation and a
line track simulation and a simulation involving an
electric field.
!filetype trxgeo !fileversion <yyyymmdd> !filedate <dow> <mmm> <dd> <hh>:<mm>:<ss> <yyyy> # # Comment #The
fileversion determines the allowable syntax within the geo file.
The filedate is generated when geo files are written, for bookkeeping only, otherwise no effect.
Comment lines start with # (hash) and can appear anywhere in the geo file.
{
!cylinder <name> <material> <cx> <cy> <cz> [ record ]
!height <height>
!radius [ <rmin> ] <rmax>
[
!phi <min> <max>
]
[
!rotate <axis> <angle>
]
[
!efieldhomo <Ex> <Ey> <Ez>
]
[
!cutoff <particle> <Ecut>
]
[
!density <density>
]
|
!sphere <name> <material> <cx> <cy> <cz> [ record ]
!radius [ <rmin> ] <rmax>
[
!theta <min> <max>
]
[
!phi <min> <max>
]
[
!efieldhomo <Ex> <Ey> <Ez>
]
[
!cutoff <particle> <Ecut>
]
[
!density <density>
]
|
!box <name> <material> <cx> <cy> <cz> [ record ]
!size <dx> <dy> <dz>
[
!rotate <axis> <angle>
]
[
!efieldhomo <Ex> <Ey> <Ez>
]
[
!cutoff <particle> <Ecut>
]
[
!density <density>
]
}
<cx>
<cy>
<cz>
specifies the position of the centre of the volume.
The optional record keyword specifies that deposition events occuring
within the respective volume will be recorded on the listmode trackfile.
!efieldhomo specifies a homogeneous electrical field in a
volume, with the components in V/cm.
!cutoff sets the lower
energy cutoff limit for trajectory termination,
with
<particle> = { n | x | e- | e+ | ion }
specifying the particle type.
<Ecut> specifies the energy: MeV/u for ions, keV for
the other particles.
<density> allows to specify a material density (g/cm**3)
differing from the material definition. This is useful e.g. for gases
at various pressures, where the material properties are the same, except
the density.
!rotate specifies a volume rotated around the <axis>
(x,y,z) by <angle>.
All lengths are in cm, angles in degree.
!diffusion entry in the volume section.
{ !cylinder | !sphere | !box } ...
...
[
!diffusion <FWHM>
]
...
<diffusion> specifies the FWHM (in cm)
of a Gaussian distribution by which inelastic events are smeared out
in order to mimick the diffusion of radicals.
that this very crude approximation is unrelated to the
radical evaluation.
Reminder:
FWHM = sigma * sqrt( 8 ln(2) ).
!pO2 entry in the volume section.
{ !cylinder | !sphere | !box } ...
...
[
!pO2 <pO2>
]
...
pO2 specifies the partial oxygen pressure (0..1) in the respective volume.
Affects only the radical evaluation, and only
if pO2 > 0.
pO2 is converted into a concentration via:
Concentration [mol/cm3] = Kh * pO2 * NAvogadrowhere
Kh=1.3E-6[mol/cm3/atm] is Henry's constant,
and NAvogadro is the Avogadro number.
!scavenger entry in the volume section.
Affects only the radical evaluation.
Unlike chemical species,
scavengers are treated as homogeneously distributed within the volume.
{ !cylinder | !sphere | !box } ...
...
[
!scavenger <scav1> <conc1>
]
[
!scavenger <scav2> <conc2>
]
...
[
!scavenger <scavn> <concn>
]
...
The <scavi> specify scavenger molecules with concentrations [mol/cm3].
An arbitrary number of scavengers may be specified.
!scavenger O2 and !pO2 are specified,
!pO2 takes precedence.