The upgrade for the power supplies of the preamps was needed  due to the increase in power from previous runs.  Because of space constraints, however, the boxes that contain the power supplies cannot be any bigger.  The solution is to use switching power supplies instead of linear ones, which are significantly more efficient.

The noise characteristics were found to be the same when the preamps were powered by either the switching power supply or the linear one.

These power supplies are to be placed immediately outside of the calorimeter in the muon magnet steel and will be immersed in a magnetic field.  When measurements were taken of the output voltage and current of the power supplies, it was adversely affected by this magnetic field.  Therefore it will be necessary to shield the power supplies inside an iron cage to ensure good performance.  The shield cages are under way for designing and testing.  Right now the sheilding is made of two steel shells separated by an aluminum shell.

Prototype Pictures  Power Supply Pictures  RunI  Supply  Front of Supply  Back of Supply  Power Supply Module