BSD Conversion Box for Ortec 660
In testing setups, the high-voltage for the HPGe will be provided by the Ortec NIM 660 dual high-voltage module (BSD in Ortec Mode: -4V=Cold, Closed=Warm). Ensure that this module is on 'Ortec' shutdown mode by inspecting the internal jumper board positioning. The High-Voltage shutdown signal from the GRIFFIN NIM Preamp-Power module is suitable for the CAEN A1883PE High-Voltage card in a CAEN SYS1527 Mainframe (Closed=Cold, Open=Warm). Therefore this signal must be translated via the GRIFFIN NIM BSD Conversion module. The RJ45 ouput connections on the GRIFFIN NIM Preamp-Power module should be connected via a Cat-6 cable to the front-panel input of the GRIFFIN NIM BSD Conversion module. The 4 outputs on the rear of the GRIFFIN NIM BSD Conversion module should be connected to the 'BSD' input on the rear of the Ortec NIM 660 module via a BNC-BNC, RG-58 cable. The 'Enable' buttons on each module must be pressed in sequence; GRIFFIN NIM Preamp-Power module then Ortec NIM 660 dual high-voltage module. The modules will only reset if the detector is properly cold at liquid nitrogen temperature. Test the shutdown circuit by unplugging the BSD connector at the detector bulkhead. Everything should go to a trip status and not reset when the BSD connector at the bulkhead is restored. Now reset the modules again in order. The detector can now be biased to the specified operarting voltage printed on the detector dewar.
Note the input signal is only taken from pins 1 and 2 on the front panel CAT-6 connector. Note all 4 BNC signals on the back are identical.