KINE100 Storing and retrieving vertex and track parameters

CALL GSVERT (VERT,NTBEAM,NTTARG,UBUF,NUBUF,NVTX*)

VERT

( REAL) array of 3 containing the position of the vertex in the MRS;

NTBEAM

( INTEGER) beam track number origin of the vertex (0 if none exists);

NTTARG

( INTEGER) target track number origin of the vertex (0 if none exists);

UBUF

( REAL) user array of NUBUF user words to be stored in the data structure together with the vertex;

NWBUF

( INTEGER) number of user words;

NVTX

( INTEGER) number of the vertex stored (0 in case of error).

This routine stores the parameters of a vertex to which tracks should be attached via calls to GSKINE. Vertices are stored in the JVERTX data structure (see [KINE199]) and they are preserved for the whole duration of the event.

GEANT tracks one vertex at a time: all the particles of one vertex, and all the secondaries generated thereof must be transported before the particles of the next vertex are considered.

This routine should be called only from GUKINE when the initial kinematics of the event is defined. During tracking it is possible to add vertices to the JVERTX data structure, but this should be done via the GSKING routine and the appropriate variables in the /GCKING/ common block. Please see [TRAK300] for more information.

CALL GSVERU (NVTX,NUBUF,UBUF,IADR*)

NVTX

( INTEGER) vertex number;

NUBUF

( INTEGER) number of user words;

UBUF

( REAL) array of user words;

IADR

( INTEGER) position where information is stored in the user bank of the vertex.

This routine stores the first NUBUF words of array BUF in the user bank attached to vertex NVTX, starting at location IADR+1. On exit IADR is set to IADR+NUBUF, allowing subsequent filling. This allows effectively to add information to an existing vertex, whether or not it has already an user buffer. This is the only way to add user information to a vertex which has been created at tracking time by the routine GSKING via an appropriate setting of parameters in the common /GCKING/.

CALL GFVERT (NVTX,VERT*,NTBEAM*,NTTARG*,TOFG*,UBUF*,NUBUF*) Retrieves vertex parameters. The parameters have the same meaning than the ones of GSVERT.

TOFG

( REAL) time of flight when the vertex was created;

CALL GPVERT (IVTX)

Prints vertex parameters.

IVTX

( INTEGER) vertex number to be printed, all vertices if IVTX=0;

CALL GSKINE (PLAB,IPART,NV,UBUF,NUBUF,NT*)

PLAB

( REAL) array of 3 containing the components of the momentum of the particle in GeV $c-1$ ;

IPART

( INTEGER) particle code (see [CONS300]);

NV

( INTEGER) number of the vertex origin of track;

UBUF

( REAL) array of NUBUF user words to be stored with the track;

NUBUF

( INTEGER) number of user words;

NT

( INTEGER) number of the stored track (0 in case of error).

This routine stores the parameters of a track in the JKINE data structure (see [KINE199]). This data structure survives for the whole event, and it is wiped out by GTRIGI at the beginning of each new event. There are two reasons to store tracks in the JKINE data structure:

• at the beginning of an event, from within GUKINE, to define the initial kinematics of the event, i.e. the particles which GEANT will transport. This must be done through GSKINE after that the vertices from which the particles originate have been defined through GSVERT;
• during tracking, to preserve the kinematic information of a particular track till the end of the current event. In this case the user should not call GSKINE directly, but rather set the appropriate flags in the /GCKING/ common block and call GSKING. This is explained in detail in [TRAK300].

CALL GSKINU (NT,NUBUF,UBUF,IADR*)

NT

( INTEGER) track number;

NUBUF

( INTEGER) number of user words;

UBUF

( REAL) array of user words;

IADR

( INTEGER) position where information is stored in the user bank of the track.

This routine stores the first NUBUF words of array BUF in the user bank attached to track NT, starting at location IADR+1. On exit IADR is set to IADR+NUBUF, allowing subsequent filling. This allows effectively to add information to an existing track, whether or not it has already an user buffer. This is the only way to add user information to a track which has been created at tracking time by the routine GSKING via an appropriate setting of parameters in the common /GCKING/.

CALL GFKINE (ITRA,VERT*,PVERT*,IPART*,NVERT*,UBUF*,NUBUF*) Retrieves long-life track parameters. The parameters have the same meaning than the ones of GSKINE.

CALL GPKINE (ITRA) Prints initial track parameters.

ITRA

( INTEGER) track to be printed, all tracks if IVTX=0;

KINE199