The database file contains constants of the spectrometers and their detectors. In the future this database can be accessed with a package developed around HEPDB. For the time being it is a plain ASCII file. We describe here how the part for spectrometer E looks like, the part for the other spectreometer has the same structure.
The first seven lines of the database file contain drift chamber information and should look as follows:
1 1 1 1 416 320 416 320 0.0000 0.0240 0.2720 0.2960 0.0000 40.000 0.0000 40.000 0.0050 0.0050 0.0050 0.0050 0.5000 0.5000 0.5000 0.5000 0.52E-01 0.52E-01 0.52E-01 0.52E-01 2.0 0.0 0.0 0.0 -4.479051e-5 1.588897e-4 3.861646e-4 -6.223269e-5
The meaning of these lines is:
Next lines contain for each wire plane and each wire, the wire number and the TDC offsets. Each line contains information for five wires, f.i.:
1 503.0 2 503.0 3 503.0 4 503.0 5 503.0
If the wire number is negative then this wire will not be used in the analysis. This should be followed by lines containing wire number and position:
1 1.42057 2 1.41557 3 1.41057 4 1.40557 5 1.40057
Now information about the trigger detectors comes (first S1, then S2)
0.405 0.40 0.750 0.0150 0.00 42.46 37.18 36.65 39.97 36.02 45.50 46.86 30.57 16.25 37.34 18.28 74.78 66.88 32.37 0.0 0.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.395 0.40 2.000 0.0150 26.38 19.86 43.99 86.05 28.40 39.03 72.97 55.40 48.41 31.00 27.92 0.00 48.41 57.83 98.86 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0
The meaning of these lines is:
At the end of the database the transport information of the spectrometer is
given. The first number is the radius of the central ray through the dipoles.
Then the coefficients for polynome of the spectrometer constant
(MeV/kG) are given and it is followed by
the dispersion constants
which together link dispersive position
and momentum p through the relation:
The number following the dispersion constants indicates the definition of the transport matrix:
1.400 41.972 0.0 0.0 1.2063E-01 1.1105E-02 -1.0599E-03 -1.1160E-04 -1.2408E-04 0.0 2
It is completed with a list of the transfer elements. Each line contains the
following information. The first INTEGER tells whether the transfer
element will be fitted when an OPTIMIZE command has been given.
A 0
means keep fixed, a 1
means fit it and -1
indicates
that when reconstructing the vertex at the target the first time use the
values in the database but keep them fixed on zero during the fit.
This is followed by the dependence of the particular transfer
coefficient and its name:
For example, the line for looks like
1 1 0 0 -5.748E-1 1.254E-3 -1.028E-5 6.655E-8 0.000E+0 -1.21E-12 'T100'