Accelerator Update - June 11-June 13
The integrated luminosity for last week was 4674.7 nb-1.
Experts changed the controls for a Pbar Debuncher RF station (DRF1) at 1:18 PM as a test. Controls were then returned to normal.
During the morning a Linac RF station (KRF1) had been causing problems. At 2:58 PM, after Operations loaded protons into the TeV for the shot, Linac technicians began repairing the station.
Booster vacuum valves closed at 4:26 PM, stopping all downstream beam. Operators had the valves open and beam restored five minutes later.
Booster next suffered trips on four RF stations (BRF3, 4, 5, & 6). They all reset okay.
At 10 PM, the Linac and Booster beam intensity had dropped. Operators tuned the beam.
Thursday June 12
Booster had two RF stations (BRF11 & 12) trip off at 2:24 AM. Operators reset BRF11, but didn't get BRF12 back on until 2:44 AM.
At 3:16 AM, a TeV RF station (TRF5) tripped off.
Problems with the Booster beam appeared again at 5:37 AM. Operators resumed tuning the beam, which of course affected the MiniBooNE beam. Then, at 6:39 AM, two RF stations (BRF13, & 14) tripped off. Operators reset the stations.
TeV experts began end-of-store studies at 7:31 AM.
Operations terminated store 2673 at 8:21 AM. TeV experts began a beam maintenance period and Switchyard experts began a study period.
Operations turned TRF5 back on at 8:46 AM.
At noon, Operations put the TeV into shot setup.
Booster suffered a vacuum burst at 1:08 PM. A vacuum tech began changing a vacuum pump power supply at 2:43 PM. Stacking and MiniBooNE beam resumed a half hour later.
At 3:18 PM, Operations established store 2676 with an initial luminosity of 27.54E30. Pbar resumed stacking.
Problems with Linac quadrupole controls and power supplies for QPS308 and 307 began at 6:22 PM. They continued until 7:33 PM when operators called in an expert to change out a power supply. The expert had QPS307 operational by 8:16 PM.
Booster beam problems reappeared at 10:27 PM. Operators resumed tuning.
Another Booster vacuum burst occurred at 11 PM.
Friday June 13
Operators returned from their Booster access at 12:56 AM. BRF4 simply needed a new aspirin; humidity had caused it to disintegrate. Aspirin tablets are used in spring style switches because they readily dissolve when hit with water.
At 1:33 AM, Operations resumed sending beam to Booster and MiniBooNE, but the Booster beam was very poor.
A TeV expert began a study period at 4:32 AM.
A Pbar Debuncher quadrupole power supply fault halted stacking at 6:56 AM. Operators managed to get the power supply working fifteen minutes later.
At 7:10 AM, the Pbar stack was lost. An Accumulator device (A:LQ) tripped off. Operators called in an expert.
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|last modified 6/16/2003 email Fermilab|