Requirements

The basic requirements for the HV board, as agreed upon during the March 1998 ATLAS week, are:

• Provide HV to 24 MDTs
• Gracefully handle a shorted or sparking MDT
• Provide a fusible disconnect for a group of 8 or fewer MDTs

In addition, this board must be part of a complete HV system which meets the following requirements:

1.

Reliability in normal operation (maintaining the noise performance of the chambers by not compromising the Faraday cage)

2.

Adhering to the ATLAS muon grounding policy[1] (avoiding ground loops)

3.

Reliability of the fuse blowing operations

4.

Ability to operate in negative HV mode for chamber ``annealing''.

A solution is proposed here which appears to meet all of the above criteria, but it should be noted that as of this writing it has not been tested. General details of operation of such a fuse system are described elsewhere[2] and will not be repeated here.