Update 25 July 2017
LH2 commissioning and preparations for the next cycle
Update: liquid-hydrogen system commissioning:¶
Progress on the preparation of the liquid-hydrogen system has been steady since CM48 in Belgrade. The modifications to the turret required to address the issues raised during commissioning with neon have all been addressed. The turret has been installed in the focus coil and the connections to the liquid-hydrogen vessel have been made.
Last week, the absorber/focus-coil module was placed back on the beam line. Vacuum in the hydrogen vessel, the safety volume and the interspace was established at the required levels and the cool-down of the system with helium gas was initiated by Mark Tucker on Saturday 22Jul17, a milestone for the preparation of the system. Another milestone was passed yesterday (Monday, 24Jul17) morning when the temperature of the vessel fell below 75K; the temperature at which the change is made from helium to the gas which will be liquified, in this case neon. Neon is presently being liquified by the system; the third, and final, test of the system with neon is now underway.
On Thursday 20Jul17, the preliminary safety tour of the liquid-hydrogen system took place. This is the first formal step in gaining permission to operate the system with liquid hydrogen. It is testament to the care with which the liquid-hydrogen team have prepared the system that only a few, minor, issues were identified by the reviewers. These issues will be addressed once the final system test with neon is complete.
The timetable now is:
• A full system test with liquid neon will be performed. This test will include the test of each of the sequences required during operation with hydrogen. The safety systems will also be tested. It is anticipated that the full set of tests will complete around 04Aug17;
• The system will be warmed up to allow the hydrogen-quench line to be finalised. In parallel to the completion of the hydrogen-quench line, a final round of leak checking on the hydrogen-gas panel will be carried out. It is anticipated that this will take place in the week of 07Aug17;
• Following the completion of the above work, a second, hopefully final, safety tour will take place that, if successful, will allow the system to be signed off as safe to operate with hydrogen.
The culmination of the steps listed above, the second hydrogen safety tour, should take place in around three weeks time. I would like to congratulate Josef Boehm, Mark Tucker, Phil Warburton and the whole of the liquid-hydrogen team for pushing the work past the two critical milestones that have just been achieved.
Preparation for operation in Cycle 2017/02:¶
The next User Cycle, 2017/02 starts on 19Sep17, in only eight-weeks time. Steve Boyd and Colin Whyte will take the lead in the coordination of the steps necessary to bring up all the MICE systems. Careful scheduling will be required to dovetail the work on the superconducting magnets, the tracker readout, the MICE Muon Beam and target and all the instrumentation, readout and control systems that we require to run.
Of particular importance in the short term is a thorough and careful review of the alarm handler, its limits and the way in which it is used. This will be coordinated by the Duty Coordinator (presently Paul Hodgson). Ajit Kurup will implement necessary changes to alarm limits etc. The “owners” of each system giving an alarm will be contacted and supported to make the changes necessary to remove the alarm or to perform the analysis required to set more appropriate limits. Everyone appreciates the importance of this work, it is a necessary first step to bringing up the system for data taking.
In Belgrade we discussed the programme that we wish to carry out in the coming Cycle and identified the bones of a strong case for extended running. However, we need to be clear that Cycle 2017/02 may be our last. This means that we need to be ready to start when ISIS delivers stable operation on 19Sep17, which in turn means that our pre-Cycle preparations must be both efficient and effective. Plans have been laid for the recommissioning of the magnets, the tracker electronics and readout and other systems. I am confident that we shall be in good shape for data taking in September.
With best wishes …