!filetype trxsrc !fileversion <yyyymmdd> !filedate <dow> <mmm> <dd> <hh>:<mm>:<ss> <yyyy> # # Comment # { !particle <projectile> !energy [ <E> [ <prob> ] ] [ <E> <dN/dE> ... ] !direction { "*" | <theta> <phi> | <thmin> <thmax> <phmin> <phmax> } { !cylinder <cx> <cy> <cz> [ record ] !height <height> !radius [ <rmin> ] <rmax> [ !phi <min> <max> ] [ !rotate <axis> <angle> ] | !sphere <cx> <cx> <cx> [ record ] !radius [ <rmin> ] <rmax> [ !theta <min> <max> ] [ !phi <min> <max> ] | !box <cx> <cx> <cx> [ record ] !size <dx> <dy> <dz> [ !rotate <axis> <angle> ] | }
<projectile>
specifies the primary particle type.
As of TRAX
version >= 1102,
multiple projectiles are possible and will be sampled from their cumulative distributions.
The !energy
tag specifies either a monoenergetic source
or an energy distribution given as a pair of numbers
<E> <dN/dE>.
From this distribution the actual energy will be sampled.
Note that the distribution is assumed to be a histogram, i.e. the
<E>
values are represent bin boundaries,
and the <dN/dE>.
are assumed to be normalized to the bin width.
The distribution function <dN/dE> need not be normalized to 1.0,
normalization will be performed internally by simple cumulation.
Alternatively, for multiple projectiles, a single energy tag
can be specified with a single probability (TRAX
version >= 1102).
The !direction
tag allows to specify
*
2 numbers
4 numbers
The
!cylinder
,
!sphere
,
!box
keywords define the spatial source distribution,
the meaning is the same as for the
geometry volumes.
They might be used to implement volume, area, and
line sources with the given geometry.
The spatial source distribution is common to all particles.
!rotate
specifies a source volume rotated around the <axis>
(x,y,z
) by <angle>
.
This transformation is also applied to the particle's emission direction.
All lengths are in cm, angles in degree.
Energies are in keV, except for ions, for which it is in MeV/u.
The usual file name extension is .src
.
An example with an energy distribution is
here.
[ !distributionmode { "histogram" | "function" } ] !particle ... [ !distributionmode { "histogram" | "function" } ] [ !direction <cos(theta)> <dN/dOmega(theta,phi)> ... ] [ !ddcs !dim1 <E_1> <cos(theta_11)> <dN/dE/dOmega(theta,phi)> ... !dim1 <E_2> <cos(theta_21)> <dN/dE/dOmega(theta,phi)> ... !dim1 <E_n2> ]With
!distributionmode
the interpretation of the data columns can be selected.
histogram
assumes the data in the first column to be bin limits,
the data in the second column to be spectrum content divided by bin width.
This is the default, as before.
function
assumes the data to be pairs of numbers representing
break point and associated distribution function value, respectively.
Distribution functions need not be normalized to 1.0. This operation will be
performed internally by trapezoidal integration.
The !distributionmode
tag may appear before the
!particle
tag, in which case it holds globally,
or it may appear within a !particle
section, in which case
it selects the distribution mode specifically for that particle.
The !direction
tag allows to specify polar angular distributions
<dN/dOmega(theta,phi)>
as a function of cos(theta)
.
The azimuthal direction is chosen isotropically.
!ddcs
now allows to specify distributions in two dimensions,
energy and cos(theta) (double differential cross section).
The !dim1
tag introduces the polar angular distribution
for a particular energy E_{i}
, followed by the distribution
values.
In histogram
distribution mode, the last !dim1
closes the !ddcs
section without data following, thus representing
an upper bin limit.
Note that for file version 20170307, each particle section must individually
specify both energy and direction, using either a !ddcs
or both an !energy
and a !direction
.