Beampipe support geometry and other news

Documentation for the beampipe support geometry description development

After the completion of the 2007 run, the SVT and the SSD were removed from the STAR detector along with there utility lines. The support structure for the beampipe remained, however.

The following drawings describe the structure of the beampipe support as it exists in the late 2007 and probably throughout 2008

Further corrections to the SVT geometry model
 
In the course of recent discussion of the beampipe support and shield material, Dave Lynn has found that even though according to the plans, the material of the cooling water channels in the SVT was specified as Be, in reality carbon composite material was used for that purpose. Below, there are materil vs pseudorapidity plots for the "old" and "new" codes
 
 
 
It can be seen that the difference is of the order of 0.4% rad. length on top of the existing (roughly) 6%. This is enough grounds for cutting a new version of the geometry and will shall create a geometry tag Y2007A which will reflect such change.