The VSAT project has been facing a very difficult situation for LEP II conditions. At the same time as the VSAT group was suffering from a constantly decrease of manpower, an upgrade of detector and software had to be made to assimilate the new signal and physics conditions. Many of the key personnel that were responsible for the design and construction of the detector and software system, have left both the project and the University.
In spite of these difficulties, detector performance has been boosted and solutions to all problems have been generated. The movement of the detector closer to the beam pipe increased the VSAT gamma-gamma cross section as expected. The background rate did however also heavily increase, but thanks to the good resolution in the VSAT strip-planes background rejection can be made very effective.
The universality of the trigger system is able to handle the new severe trigger rates and VSAT has adapted to DELPHI specifications. Some degeneration of the FAD planes can be seen in the outer modules, but with only two more years of data taking this does not present any problem. Resolution are obtained below 5%. The energy response of the FAD planes are now well understood and stable non saturated signals are obtained.
The offline processing and analysis have been optimized both to the new conditions of the data as well as the amount of man hours available. Tools and programs have been created to minimize tedious offline work and very satisfactory results have been obtained.