FOC Instrument Science Report 067 "History of High Background Events Observed in the f/48 Relay" 11/92 by W. Hack and A .Nota Abstract excerpted from the report: This report discusses the occurrences of high background levels in the f/48 relay up to Day 261 (1992) when the high-voltage supply for the image intensifier switched off immediately after powering up. We will give in this report the history of the occurrences of the high background events and provide some statistics to show the flux levels detected by the f/48 relay during the observations taken prior to the high-voltage shutdown of Day 261. It is currently believed that the high background rates are the result of a corona breakdown due to delamination of the potting between the 8kV and 12kV supply lines to the f/48 intensifier tube.
