TRiP98 spectra files gd (ASCII) import format
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Spectra files gd (ASCII) import format

Files for gd ASCII import must be organized exactly as they are created by the
spc /export(gd)
command, i.e. with the naming conventions
<prefix><proj><targ>.<uuu><eeeee>.um<dddddd>.spc.gd
<prefix><proj><targ>.<uuu><eeeee>.nn0.spc.gd
where <prefix> is an optional prefix, <proj> denotes the projectile, <targ> the target material, <uuu> the unit ( keV, MeV, GeV) and <eeeee> the energy in these units, with the decimal point after the middle digit. <dddddd> is the depth value in micrometers. Example:
test.12C.H2O.MeV27000.um*.spc.gd
test.12C.H2O.MeV27000.nn0.spc.gd
refers to spectra at all depths for 12C beams of 270 MeV/u primary energy. The various components of the file name are significant and are used to derive projectile, target, primary energy and depth of the spectra to be imported.
Note that the existence of a .nn0.spc.gd file is implied without specifying it.
The format of a .spc.gd file is as follows:
header line                                     (1st line always ignored)
...                                             (other lines ignored until first H:)  
H: x y(Z=<z1>,A=<a1>),h1 n(cum),l0  (header for first Z,A pair)
<ebin> <bincontent> [<running sum>]
... more bin data

H: x y(Z=<z2>,A=<a2>),h2 n(cum),l0  (header for second Z,A pair)
<ebin> <bincontent> [<running sum>]
... more bin data
    
Note that the header lines, in particular the Z,A-description in parantheses, must be formatted exactly as shown. gd-style data modifications are not evaluated.
Lines starting with valid numbers are interpreted as spectrum histogram bins, each line must contain the lower energy bin limit (in MeV/u) and the bin content, normalized to the bin energy width (in MeV/u) and to an integral primary particle number of one. The third column is optional, it represents the running integral of the histogram ("cumulated histogram"), if not present, the histogram values will be integrated internally.
The last data entry belonging to a H:-block is assumed to be the uppermost bin limit (with the corresponding bin content value being meaningless).
Lines other than H:- or data lines are ignored.
An example can be found here
The *.nn0.spc.gd file serves as a kind of header file, its prime purpose is to specify quantities which cannot be retrieved elsewhere, such as the Bragg peak position (needed for the interpolation of spectra) and the overall normalization. These values are hidden in gd comment lines, e.g.:
c:importgd: P=2.59358 [g/cm**2]
c:importgd: N=1 [particles]
c:importgd: Version=19980704
the rest of the *.nn0.spc.gd file is ignored.
| GSI Biophysics | TRiP98 long write-up |
Last updated:
$Id: trip98fmtspcascii.html,v 1.2 2009/03/13 17:26:24 kraemer Exp $
M.Kraemer@gsi.de