The only problem at Linac 2 were “flash-overs”, i.e. sparks at the outside of the vacuum chamber (and may-be inside) between the source at high potential and pieces (Faraday cage) at ground potential. At the worst point, it was impossible to hold the source at 90 kV. The rate, es with which such flash-overs occur, diminished immediately after cleaning and further decreases with time. The air for ventilation (possible source of dirt) is taken now from the Linac tunnel.
The source of Linac 3 runs with indium ions. At the moment, there is a problem with the power supplies of the steerers. The repair (replacement of transistors) will last about a day (unless people doing the work are unavailable to work on other problems).
D. Küchler warns the PSB team (see test with Indium planned this week in the PSB) that the oven (in the source to produce vapour of the element to be produced) life-time is reduced with Indium ions. Last time, the oven was broken after 8 days of running and a replacement takes about 8 to 24 hours. Note that the reduced life-time of the oven will apply also for the SPS fixed target run scheduled in 2003.
Next BS meeting Tuesday April 30, 2002 at 10.00 in the MCR
Minutes by Ch. Carli