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.
Don Summers reports that
Eleven crates with six tons of RF equipment from Mississippi have now arrived in the United Kingdom at MICE including everything needed for the TIARA test.
Many thanks to everyone for their help.
Bill of Materials:
291 MEGA RF transmission lines, elbows, heliaxes, crossovers...
11 Altronic 200 kiolowatt RF dummy loads
10 Dimtel LLRF4 Amplifier Controller Boards
4 B1300 Capacitorr SAES Getter Vacuum Pumps
After a final two days of running over the weekend, the EMR commissioning run is now complete. In spite of a few issues with the DAQ configuration, we now have data with all Step I detectors in operation.
Arrived safely and is in the R55 reception area now. The plan is to move it into R9 for the tracker installation.
The R89 Data Centre is required to upgrade the UPS (Uninterruptible PowerSupply) room in order to support the current and future demands on power supply. The upgrade will enable an increase in supply from 400amps to 630amps.
This upgrade will take place on 05 November, and in order to minimise the effect on STFC critical IT services they will be connected via an alternate power supply. There will be some short disruptions whilst these supplies are being connected and removed, impacting on access to; internet, SharePoint, web servers and Scientific Computing services.
In order to fulfil the health and safety legislative requirements for running a Data Centre, we are required to test our power connections every 3-5 years. This work will be carried out over 05 and 06 November. The Data Centre will be running at risk during this period.
Email for the RAL site will be managed and run from Daresbury from 01 November onwards.
Impact of the work¶
On the morning of the 05 November between the hours of 06:30 and 08:00, the STFC core networking equipment will be connected to the alternate power supply. This will cause a short disruption to; internet, SharePoint, web servers and Scientific Computing services. Any further problems after this time will be communicated.
Once the work has been completed (approx 14:00), the networking equipment will be re-connected to the main power supply, again, this will cause a short disruption to; internet, SharePoint, web servers and Scientific Computing services. Any further problems after this time will be communicated.
It is not anticipated that the power testing work will cause any disruption to the IT services listed above. But in the unlikely event that this does occur, it will be communicated.
Over the weekend we took a full momentum scan using electron and pion beams to explore the behaviour of the EMR.
This would not have been possible without the EMR visualization software provided by Ruslan and Yordan's diligent work through Thursday and Friday.
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