Global_arrays

NTRACK: the number of tracks in the track bank.

ITRACK(NPU): the track pointer for the NPU'th particle on the USTACK. ( used only during the WRITING of the track bank and therefore not of interest to most users.)

IQT(IT): The charge of particle IT.

ITT(IT): The particle type of track IT (same conv. as USTACK)

IAUXT(IT): Auxillary particle type of IT ( " " " " )

IPAR(IT): Index of parent track (0 if primary).

ETB(IT): Total energy of track IT at creation.

IRB(IT): index of creation region.

XB(IT),YB(IT),ZB(IT): X,Y,Z positions at creation vertex.

UB(IT),VB(IT),WB(IT): directional cosines of particle at creation vertex.

TB(IT): time of birth in nS.

IRF(IT): index of final region (i.e. region where particle, stops, decays, of is absorbed ).

XF(IT),YF(IT),ZF(IT): X,Y,Z positions at final vertex.

UF(IT),VF(IT),WF(IT): directional cosines of particle at final vertex.

TF(IT): time at which particle disappears in nS.

IFATE(IT): a "fate code" indicating the way in which the IT'th track was terminated.

=1 ==> came to rest due to energy loss.

2 ==> decayed in flight.

3 ==> absorbed in nuclear interaction.

4 ==> IDISC=1 (particle left detector).

5 ==> Neutrino or neutron, not tracked in this version. 6 ==> discarded due to IQUIT=1 or IDISCU=1

7 ==> T > Tmax tracking stopped.

Region_arrays

The arrays described below comprise a detailed record of the track's development. Tracks, or segments thereof, can be divided into two classes, showering and non-showering. Non-showering tracks typically follow a well defined trajectory between creation and termination along which they deposit their energy. Showering tracks divide themselves into several branches and deposit energy over a comparatively large spacial volume. This requires that the region associated arrays (described below) be defined differently for the two classes. Since class is an attribute of the region-plus-track combination and not just the track, a single track may contain regions of both classes. An example of this might be a high energy photon which travels in a straight line (non-showering) until con- version where it becomes a showering track. (In the present version of the program, however, photon tracks are considered to be entirely of the showering class.) NTREG(IT): the total number of regions through which a track passes or deposits energy in. Note that for non- showering tracks if a given region is entered, left, and then reentered, it will be counted twice. JTRACK(IT): pointer to last region (at this juncture NTREG and JTRACK are the same.) ( one usually includes the statement JT=JTRACK(IT) )

IRT(JT,IT): region index of JT'th region for IT'th track.

ITSTAT(JT,IT): flag to indicate region class =0 ==> Non showering =1 ==> showering

Additional Information on:

  • Non-showering_tracks
  • Showering_tracks
  • Drift_Chamber
  • Range_Chamber_arrays