To the right is a picture of the new emiT HV rack. It is much smaller and simpler than the previous rack, and is contained in a single unit (as opposed to having a separate HV transformer). The eventual plan is to have two HV output cables: a 3-conductor cable for the +/- 5 V (and ground) to run the external fiber drivers, and a 5-conductor cable for the +/- 6V (and ground) for the preamps, the detector bias, and bias ground. The fiber drivers tend to be noisy, and so are being isolated as much as possible from the electronics inside the vacuum. The actual set-up is a bit different from this at the moment, as described below.

Some of the details of the connections to the rack are illustrated to the left. The male bayonet for a 3-conductor HV cable rated at 70 kV. The HV input from the Bertan. A suitable plug and socket for this cable needs to be found. These cables are being used for temporary testing. They will be removed in the final system. These are the female sockets for the 3-conductor HV cables. One of them will be converted to a similar socket for a 5-conductor cable. A 12" ruler for scale.

The guts of the HV rack are shown to the right. +6 V and -6 V power supplies for the preamps. +5 V and -5 V power supplies for the fiber drivers, etc. Variable power supply for surface-barrier bias. The green power supplies are temporary so that we can run PINs, PIPS, and SBDs simultaneously. They will eventually be replaced by displays showing the bias voltage and leakage current, a leakage-current interlock, and fiber circuitry to send the bias voltage and leakage current to the DAQ. Ring at HV ground to prevent arcing from sharp points on power supplies. 12" ruler for scale.

Please send comments to: steiger@npl.washington.edu
Last update: October 10, 2000