The user tools

The data structure JSET is built through calls to the routine GSDET or GSDETV which assign detectors to sets and define their parameters. After this, the following routines can be called, for each detector, to complete the structure:

GSDETH

provides the parameters required for the storage of the hit elements in the data structure JHITS, such as the packing and scaling conventions;

GSDETD

provides the parameters required for the storage of the digitisations in the structure JDIGI, such as the packing conventions;

GSDETU

adds the user parameters, which may consist, for instance, of the intrinsic detector characteristics needed for computing the digitisations.

To permit storage of more than one type of hit for a given sensitive detector, or to provide additional detector entries, detector aliases can be defined through calls to the routine GSDETA. They are entered in the JSET structure as new detectors, with the same geometrical characteristics as the original one. The user has the possibility to call appropriate routines GSDETH, GSDETD and GSDETU for this new detector.

During the tracking, for each step inside the sensitive detectors, under control of the subroutine GUSTEP, the hits can be stored in the data structure JHITS through the subroutine GSAHIT (or GSCHIT, more appropriate for calorimetry). For each hit the information consists of:

• the reference to the track in the structure JKINE;
• the packed identifier of the physical detector;
• the packed data for the different elements of the hit.

When the tracking has been completed for the whole event the digitisations can be computed in the user subroutine GUDIGI which may extract the hits with the subroutine GFHITS and store the digitisations in the data structure JDIGI, with the subroutine GSDIGI. For each digitisation the information should at least consist of:

• the reference to the track(s);
• the packed identifier of the physical detector;
• the packed data for the digitisation itself.