BL1A was started yesterday and brought up to 10μA.  A problem was noticed with the T1 protect monitor (the right and bottom plates were not showing any response when the beam was swept across the monitor).  The protect monitor is new and was installed on the target assembly in February 2012, so this is the first time it has seen beam.  A 'blip' test was performed on the monitor in the hot cell and once again from the mezzanine after the target had been installed in the beam line.  Both tests showed that the monitor was performing normally, so an internal wiring mistake on the monitor was initially suspected and it was decided that the T1-MK1 target should be swapped with the T1-MK2 target.

Today the T1 monolith was uncovered, the T1-MK1 target was moved to the storage pit, and the T1-MK2 target was moved from the hot cell to the beam line.  The T1 volume pumped down normally after installation and a 'blip' test performed from the mezzanine showed that the protect monitor on the new target was functioning normally.  The potentiometer look-up tables were switched to the appropriate target (initially Graham Waters had difficulty with the control software, but was able to solve the problem by accessing the program remotely).  The T1 target is now ready for BL1A start-up.

This afternoon Bill Rawnsley discovered that there were two different protect monitor designs, one with a different internal wiring configuration than what has been used in the past.  If the protect monitor on the T1-MK1 target is the design with the different configuration, this could explain the symptoms observed yesterday.  If we had known this earlier, it may have been possible to solve the problem by installing a simple wire adapter at the mezzanine to switch the wires in the connector to the same configuration as the original design and the target swap would not have been necessary (saving time, dose, and the potential for damaging equipment due to handling).  This will be investigated further to determine if it is really the case.