Half-disks volume organization

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The reorganization of the FVTX volumes allows for easier implementation of alignment corrections once we get survey information on the
  • position of wedges in the half-disks
  • half-disks in the cages
  • cages in the VTX/FVTX frames and
  • the VTX/FVTX frames in the hall.
In Geant3, the silicon cage SICG holds the FVTX North and South arms SCMS and SCMN, as well as the barrel volumes and support structures.

These in turn hold the (half-)cages SCM1,2 in the South, and (half-)cages SCM3,4 in the North.

Cage SCM1 holds half-disks SI05,7,9,11 etc. Positions are as follows: 

          SCM2           West          SCM4
          +-------------\    /------------+
          | SI06 08 10   \  /   16 18 20  |
          |            12    14           |
  South   +---------------  --------------+   North
          |            11    13           |
          |   05 07 09   /  \   15 17 19  |
          +-------------/    \------------+
          SCM1           East          SCM3
SI05 and SI06 make up station 4 South etc.

Files involved:
src/svx/svx_fvtx.f
src/svx/svx_digi.f
src/svx/ svx.f
src/root/SvxPISAHit.cc
src/root/SvxPISAHit.h
src/root/rootAncSvx.cc
src/root/PISAEvent.cc
inc/fpdlink.inc

(committed 8 Feb 2011)
SCM1,2,3,4 are the cage mother volumes. Since the wedges hang over the centerline of the disks, the mother volume spans more than 180°. Therefore there are ovelapping volumes: SCM1 overlaps with SCM2, and SCM3 overlaps SCM4, and these have to be declared 'MANY' when they are positioned. In order to limit the GEANT searches, these 'MANY' volumes are immediately enclosed by holding volume SCMN or S, which are declared 'ONLY'. Volumes SCMN and SCMS should not be moved during alignment. Move the cages SCM1-4 instead.
Each half-disk has the support disk SUPB and 24 wedge modules SIPB, which in turn consist of carbon support SICB, hdi HDIB, readout chips CHMR, and silicon SISB. The silicon has some passive bits, and 2 columns SISI, which can optionally be divided into 70μm strips


Hubert van Hecke
Last modified: Tue Feb 8 15:50:44 MST 2011