MICE Target Failure and 2011 running
Report from the Target Group¶
During running on Wednesday 13 July, the target in ISIS, which had previously
been operating normally, performed two actuations where it was observed
to hit the lower stop rather than returning to "hold" position. Shortly
afterwards, it overshot the hold position and went too high. This
behaviour has not been observed before, and is thought to be due to a
malfunction of the position-measuring system.
The target frame has now been raised so that the target cannot intercept
the beam. Further investigations are in progress, but it appears likely
that the target has jammed in the upper bearing and cannot be
actuated. If this is the case, the target will be out of action until
it can be replaced in the next ISIS shut-down".
Implications of the target failure: Spokesman¶
This target has successfully performed 571k pulses and it had been
decided in agreement with ISIS to leave it in the ring until it broke
while better design was being developed. Both of these things have now
happened. We are fortunate enough to have at least one design that works
(and an even better one in preparation).
This means that the summer run had to be canceled, something that caused
disappointment -- we all like to see MICE alive and running!
Nevertheless the EMR test, which was the main aim of the run, could be
sufficiently successful in the few days of running starting 29 June. The
EMR will therefore be sent back to University of Geneva.
The baseline schedule is that we re-install a new target before the
planned running in February-March 2012 (full EMR run). If anyone has a
strongly motivated proposal for data taking before then please let the
MOM and Spokesperson know as soon as possible.
There is no reason to believe that this incident will have an impact on
the schedule that was agreed at the collaboration meeting (EMR run in
February 2012, StepIV run in October 2012 to March 2013).
August Bank Holiday at RAL: Friday 26th – Monday 29th August:¶
· R22 closes at 4pm on Fri 26th Aug and re-opens at 07:30 on Tuesday 30th August
· R1 Coffee Lounge closes at 4pm on Fri 26th Aug and re-opens at 08:30 on Wednesday 31st August
· Electron cafe closes at 3:30pm on Fri 26th Aug and re-opens at 08:30 on Tuesday 30th August
· Breakfast will be available in Ridgeway House for anyone who is at RAL over the weekend
Reduced service on Tuesday 30 August 2011:
· R22 open for breakfast and lunch only, from 07:30 to 16:00 (there will be no dinner service)
· Electron Cafe open, from 08:30 to 15:30
· R1 Coffee Lounge closed
Both beams are down and any guests in staying in Ridgeway will be advised on alternative venues for dinner.