Source file format


File version 20000118

!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

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.

File version 20170307

In addition to version 20000118:
[
!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 Ei, 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.


Last updated: M.Kraemer,
$Id: traxfmtsrc.html,v 1.17 2017/03/14 15:50:04 kraemer Exp $