• Decay solenoid – seal repair completed 8th April, cooldown either underway or imminent
• R78 target re-fit completed on 7th April, new bearings and shaft, running resumed
• Proton absorber under final test, install this shutdown
• SS2 move to R5.2 confirmed for 29th April
• Beamstopper should be fixed April 11th
• Request to survey online target during shutdown
• Bolt will be fitted to top of Potterax door (to solve PPS problems)
• PPD safety tour on 16th April, frantic tidy up in progress
• New MOM phone being purchased
• Rack room two will be ready for flooring 14th April
• TIARA/UMISS RF gear will be packed for DL April 16th
• Easter shutdown dates: 7th April – 6th May
- MICE ran on Sunday 6th April to test the new target double dip rate.
The target performed as expected and generated no problems in ISIS. Everyone is happy.
- The new DAQ was also tested with data and appeared to be working well too.
- A few niggling issues (glitch with the PPS, repair needed to the beam stop, a walk
in during the hall search) but all in all a very successful shift
From Monday 14th: Ray Gamet
- Decay solenoid – seal repair confirmed for Tuesday, 8th April
- Vacuum system mock-up complete
- Safety tour of R9 & R5.2 on April 16th
- RR2 flooring and cabling in progress, on schedule for rack delivery in May
- Tracker installation complete, site visit for solenoid movement 8th April
Hall Summary, 27-3-14¶
• Decay solenoid – fridge compressor replacement seal expected within two weeks
• A new problem with Linde chiller – controls and gas level
• Air conditioning in Hall fixed and available
• Ex. TIARA RF gear stripped and ready to ship to DL (for commissioning second TH116)
• RR2 cable tray work making good progress, then raised floor can be finalised
• FC#1 reached 188.5 amps in flip mode; inactive this week due to tracker installation, but will resume soon with extended stability testing
• Tracker installation in SS#2 should be complete this week; transport to R5.2 tentatively arranged for last week April
• PSU in DAQ rack now fixed
• R78 target running again
• West end crane back in use – minor defect with aux. hoist on East crane
• Conventional magnets exercised OK in readiness for April 6th run
The tracker installation is almost complete. Having ordered a few missing screws that we needed to complete things, we will be attaching the lightguides to the patch panel on Monday. We have been taking pictures throughout which will be posted very soon.
Following the discussion at the collaboration meeting the MICE news will
be publishing the name of the MOM.
Currently no MOM, but Andy Nichols is acting MOM for this month.
Work is going on in lab 9 this week
The following is an update for the MICE Spectrometer Solenoid #1 (2nd unit), which is continuing to be trained at Wang NMR. An additional five training runs have been carried out since last week's update (now 13 total). The system continues to be fully operational with all quenches determined to be normal coil training. The slope of the quench progression has slowed a bit over the past week but has continued to move upwards (6A per quench average last week). The currents are now at 94% of the target values. The next SS1 training run will be carried out Sunday 16th.
The following is an update for Spectrometer Solenoid #1 (2nd unit) for the MICE Project, which is currently being trained at Wang NMR. This is the first widely distributed update for the latest training runs, which have now been under way for 10 days.
A series of issues related to the HTS leads prevented the training from being completed towards the end of CY13. The initial problem was found to be related to faulty joints that connected the thermal intercepts at the top of the HTS leads to the cryocooler 50K copper plate. This issue has since been corrected and confirmed through additional instrumentation. A second problem involved two of the eight HTS leads that were installed new from the manufacturer (HTS-110). The two leads were showing resistive behavior during low current testing. Subsequent off line measurements in an LN bath and in a test cryostat confirmed the problem with these leads. The two faulty leads have been returned to HTS-110 for further analysis. Two other pre-tested leads have since been installed in SS1.
The LN cooldown was completed on January 23rd. Proper performance of the HTS leads was confirmed through a series of low current tests.
After repairing a small vacuum leak at the power feedthroughs, SS1 appears to be fully operational. Eight training runs have now been completed. The first quench occurred at currents that were lower than any of the first quenches on SS2, but larger increases in the quench currents were seen during the early runs. The first quench was at ~41% of the target currents (flip mode) and appeared to be normal training.
Training Run#7 resulted in a quench that was 2A lower than the previous run. This quench initiated in the M2 coil, and the voltage traces appeared to be somewhat different than the other quenches, except training Run#5, which also initiated in M2. However, our analysis of the voltages indicates that these are coil training and were not caused by some other system issue such as power supply instability or a voltage tap fault. All other quenches have originated in one of the end coils with more typical voltage traces. The SS1 training now appears to be following a similar path as the final training run series for SS2 (Feb 2013, red line). The currents reached 84% of the target values during yesterday's run. SS1 training will continue on Monday.
The MICE target has reached a major milestone. Just before Christmas, the demonstration system in R78 (target S1) reached 10 million actuations. Last week, we stripped it down for examination. No dust was visible at all on the bearings or in the "dust catcher" just below the target! The only sign of wear was a slight smear of material adhering to the upper part of the shaft. After 10 M actuations, the target was behaving perfectly normally, and would still have been suitable for continued operation. However, it has now been refurbished with a new set of bearings, and testing will continue.
Work was also done last month on the target in ISIS. A faulty fibre, which prevented operation in December, was replaced in the synchrotron This appears to have been mechanically damaged during work in the recent ISIS shut-down. The fibres have been tidied into a safer route, and we plan to add additional protection during a future shut-down. After the repair, the target was successfully operated at double the rate previously used in ISIS (50/64 Hz instead of 50/128).
Incidentally, during the test, one of the target's safety systems was also exercised! The power to the water chiller was accidentally interrupted while people were working on ISIS, and the temperature monitoring system successfully cut the power, avoiding any damage.
500 kW RF achieved in the MICE Hall: The first, of the RF amplifier systems, was installed, in the MICE Hall at RAL, over the Autumn of 2013; the TIARA milestone, of delivering half a megawatt RF pulses, to a resistive dummy load, was achieved in the Hall last December.
RF Operations expected during February and early March:
The RF team intend further to operate the RF amplifier system in the MICE Hall at RAL, for periods over the window from 10 February to 7th March 2014. During periods of operation, the RF equipment areas, on the upper and lower floors at the north side of the Hall, will be out of bounds to all but the RF ops team, except in emergency. No other impact on Hall activities is expected.
If you have questions for MICE administration rather than sending emails to Rose or Debbie
directly, please send to Miceadmin@stfc.ac.uk. They both check the mailbox, so if one of them
is away your query will still be answered and having everything funnelled through one mailbox
makes it easier for them to keep records.
Nine more crates with another ton of RF equipment has moved from Mississippi to MICE.
Three tetrode RF power tubes
One 300 kilowatt RF amplifier
Four Capacitor Charging Power Supplies
Two 40 kilovolt, 70 microFarad capacitors
The solenoid is in R9 now. The first operation will be some basic electrical tests, then any remedial work thought necessary on the HTS leads in light of the investigations on SS1, then it should be all clear for the tracker installation.
The refurbishment work on tracker 1 and tracker 2 has now been completed in the the new tracker lab, including retro-fitting an LED calibration system. Both trackers now await installation in the spectrometer solenoids.
Also available in: Atom