Accelerator Update for January 23, 2008 - January 25, 2008

Wednesday January 23

The day shift began with Operations monitoring the Tevatron (TeV) store 5860 (104.51E30) and the Recycler stash (201.5E10), with the Antiproton Source stacking (32.7E10), with the Main Injector (MI), Linac, and Booster operating normally, with the Collider Detector at Fermilab (CDF) and D-Zero (D0) experiments using the colliding beams, and with the NuMI and SciBooNE / MiniBooNE (BNB) experiments taking beam.

Controls experts rebooted the Pelletron front-end at 8:06 AM.

At 8:15 AM, a Booster RF station (BRF1) tripped off. It reset.

Pelletron experts accessed MI-31 at 9:30 AM.

At 1 PM, Pelletron experts came out of access from MI-31. They reported that there was still a problem with the Pelletron’s solenoid and that cooling was poor. They will continue to investigate ways to improve electron cooling.

At 2:55 PM, Linac experts began work on the Linac 800 MHz clock power supply. Since this halted all downstream beam, Operations put Pbar into standby, and allowed MIRF experts to begin work on MIRF12.

The Linac clock power supply work was completed by 3:45 PM.

At 3:46 PM, LRF2 & 4 tripped off. After a few minutes, operators were able to reset both stations.

At 4 PM, KRF2 tripped off. It reset.

Operations reported at 4:01 PM that the Recycler had stashed antiprotons twice during the day shift.

A Pbar expert began a reverse injection study at 4:25 PM.

At 5:03 PM, KRF2 tripped off. It reset.

At 5:47 PM, KRF6 tripped off. It reset.

At 5:58 PM, BRF9 tripped off. It reset.

At 9:35 PM, KRF3 tripped off. It reset.

Operations terminated store 5860 at 10:22 PM.

Operations put the TeV into shot setup at 10:39 PM.

Operations reported at midnight that the Recycler had stashed three times during the evening shift.

Thursday January 24

The midnight shift began with the TeV in shot setup, with Operations monitoring the stash (265.9E10) and the stack (89.0E10), and with NuMI and BNB taking beam.

Operations established store 5861 at 12:50 AM with an initial luminosity of 270.05E30.

At 1:26 AM, MIRF13 tripped off. It reset, but with the reset the NuMI beam permit tripped off. The permit reset.

At 1:40 AM, BRF10 tripped off. It reset.

At 4:57 AM, KRF2 tripped off. It reset.

Operations reported at 8:01 AM that the Recycler had stashed five times during the midnight shift.

At 1:48 PM, Operations reported an unusual Recycler alarm that indicated the horizontal dampers had been turned off. Operators discovered that a Recycler expert was testing the dampers.

Operations reported at 4 PM that the Recycler had stashed four times during the day shift.

A MI expert began a MI-30 collimator study at 5:03 PM. The study ended at 5:46 PM.

A MI expert began 45-minute dump study at 5:47 PM.

At 6:21 PM, LRF3 tripped off. It reset. A Linac expert reported that he thought the interlock module was causing the problem and if the tripping got worse the module should be replaced with the module from the test station.

At 9:13 PM, KRF3 tripped off. It reset.

CDF experimenters reported at 9:30 PM that they had begun tracking chamber measurements.

Operations terminated store 5861 at 10:08 PM. CDF and D0 went into a 30-minute period of quiet time.

Operations put the TeV into shot setup at 11 PM.

At 11:02 PM, the Recycler suffered an emittance blow up that caused the loss of about 8E10 of the stash. Operators investigated the cause of the emittance problem, but found nothing obviously wrong. Operations contacted an expert.

At 11:12 PM, KRF3 tripped off. It reset.

Operations reported at midnight that the Recycler had stashed three times during the evening shift.

Friday January 25

The midnight shift began with the TeV shot setup delayed due to the Recycler emittance problem, with Operations monitoring the stash (413.8E10), with Pbar stacking (72.9E10), and with NuMI and BNB taking beam.

Operations reported at 12:54 AM that the Recycler transverse emittances were slowly coming down.

At 1:21 AM, a TeV power supply (T:VE16) tripped off due to a fuse fault. Operators aborted the protons in the machine and then changed the supply’s regulator.

Operations put the TeV through a dry squeeze at 1:52 AM.

Operations put the TeV into shot setup at 2:31 AM.

At 4:26 AM, KRF3 tripped off. It reset.

At 4:32 AM, Operations established store 5863, but then the store quenched at TeV sector F4. Operators investigated and found a TeV power supply (T:HA24) had tripped off and caused an orbit distortion, which in turn triggered an abort.

Operators reported at 5:59 AM that they were changing the power supply for T:HA24. Later, operators reported that the TeV corrector magnet had quenched.

At 6:06 AM, BRF1 tripped off. It reset.

At 6:22 AM, BRF2 tripped off. It reset.

At 6:44 AM, LRF2 tripped off for the first of three times in about one hour. It reset.

At 7:42 AM, T:HA24 tripped off with a quench indication. Operations called in a power supply expert.

Operations reported at 7:57 AM that the Recycler had stashed two times during the midnight shift.

The Plans for Friday and the Weekend

The initial plan for today is to fix T:HA24. The plans for today and the weekend are to stack, stash, and store.

Accelerator Update Archive

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