TRiP98 yield command
yield | beamenergy / echannels(0) write debug
projectile braggpos() export(gd)
target erelfwhm(0) path()
outbins(8,8,16,16) delete
braggeps(0.003)
braggdiff(0.01)
braggiter(5)
Purpose
This is the beam model. Fragment spectral distributions (differential
in charge and energy, but 1-dimensional in space) as well as derived
depth dose distributions can be calculated and stored on file.
To be functional, valid
dE/dx as well as
reaction cross section
tables must be loaded.
Note that from the 0509e release onwards
external fragmentation cross sections
have to be loaded as well.
The respective tables can be found in the
DATA/DEDX
,
DATA/SIGTOT
,
and
DATA/XS
subdirectories of the installation directory.
Parameters
- beamenergy
-
If specified, a new calculation is started with this energy (MeV/u).
- projectile
-
Primary projectile to be calculated. At present C.
- target()
-
Material. At present H2O.
- echannels(echn)
-
Number of fragment energy bins.
If
<echn>
<= 0 the number of bins
and the binsize are chosen automatically so that the relative change of energy loss
of the projectile is less than 2E-3 across a single bin.
If <echn>
> 0 this number of equidistant bins
is used.
It should be large enough
to allow for correct prediction of the depth dose maximum.
Since this is determined by the primary particle, the number
of energy bins for the primary is enlarged by a factor of 8.
The maximum fragment energy (in MeV/u) is chosen 1.1 times larger
than the original beam energy.
- braggpos(bpos)
-
Estimated position of the depth dose maximum (aka "Bragg peak"), g/cm**2.
This is very important because the internal depth spacing is chosen
relative to
<bpos>
.
Usually the calculations have to be iterated 2-3 times manually until a "stable"
position is achieved. That is, the resulting approximate peak position
should be used as a better estimate for the next iteration.
You may, however, choose bpos=0
, in this case
the iteration is performed automatically, with the following control parameters:
- bragg(bdiff)
-
For
bdiff>0
the iteration is aborted if the difference
of subsequent positions is <bdiff
.
- bragg(beps)
-
For
beps>0
the iteration is aborted if the relative change
of subsequent positions is <beps
.
beps
takes precedence over bdiff
.
- bragg(biter)
-
Maximum number of iterations to find appropriate Bragg peak position.
- erelfwhm(erelf)
-
The original beam energy is assumed to have
a spread of
<erelf>
percent FWHM.
- write
-
Writes the calculated spectra and depth dose distributions.
File naming conventions:
<path><proj><targ>.MeV<eeeee>.spc
<path><proj><targ>.MeV<eeeee>.ddd
where <eeeee>
is the energy in MeV/u times 100.
(path)
- export(fmt)
-
Exports the calculated distributions in some non-native format,
at present only <fmt>="gd" is implemented to export for the
gd plot program.
File naming convention is:
<path><proj><targ>.MeV<eeeee>.um<dddddd>.spc.gd
<path><proj><targ>.MeV<eeeee>.ddd.gd
where <eeeee>
is the energy in MeV/u times 100,
where <dddddd>
is the depth in micrometers.
(path)
- path(path)
-
Output path for the calculated distributions.
It is just a prefix put in front of the file naming convention.
Might be a directory or just part of a file name.
- delete
-
Releases memory occupied by dose profiles and spectra from previous calls of this command.
Sometimes useful if large data sets are processed.
Note that "old" data are not discarded until the allocation of new ones
is successful, which may cause memory bottlenecks.
- outbins(oblist)
-
Specifies a list of binsizes by which the output energy distributions
are compressed in order to save space and time.
- debug
-
Debug switch. Lots of output!
Remark
none
Examples
dedx "$TRIP98BEAM/DATA/DEDX/20070326.dedx" /read
sigtot "$TRIP98BEAM/DATA/SIGTOT/20070516.sigtot" /read
xs '$TRIP98BEAM/DATA/XS/0705.1H.nf.xs,$TRIP98BEAM/DATA/XS/0705.16O.nf.xs' /read
yld 270 / braggpos(14.4) write path(/s/bio/kraemer/) outbins(8,16,32)
Compute the beam model for 270 MeV/u with an estimated peak position at
14.4 cm in water. The spectra and the depth dose tables should be written
immediately after calculation into directory
/s/bio/kraemer/
. The fragment spectra are compressed by a factor
of 8 in the first third of the energy range, by 16 in the second third
and by 32 in the last third, respectively.
Last updated:
$Id: trip98cmdyld.html,v 1.13 2015/11/03 15:54:03 kraemer Exp $
M.Kraemer@gsi.de