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Accelerator Update for March 26, 2008 - March 28, 2008 |
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Wednesday March 26 The day shift began with the Tevatron (TeV) in shot setup, with Operations monitoring the Recycler stash (385.3E10), with the Antiproton Source stacking (74.8E10), with the Main Injector (MI), Linac, and Booster operating normally, with the Collider Detector at Fermilab (CDF) and DZero (D0) waiting for colliding beam, and with NuMI and the SciBooNE / MiniBooNE (BNB) experiments taking beam. At 8:38 AM, Operations reported that MI was aborting after each transfer of antiprotons to the TeV. Operators halted shot setup and put MI into stacking/NuMI mode. MI experts reported that the aborting was due to an RF switch problem. Operations reduced the beam intensity for NuMI and then resumed shot setup. Operations established store 6007 at 9:12 AM with an initial luminosity of 275.0E30. At 9:17 AM, Operations reported that they were holding off Recycler stashing until MI experts investigate a possible heat exchanger problem in MI-31. Operations resumed stashing at 9:26 AM. Pbar began a no beam study at 9:52 AM. NuMI was taking beam during this study. The Pbar study ended at 10:41 AM and stacking resumed. At 10:54 AM, a Linac Klystron RF station (KRF3) tripped off. It reset. A MI expert reset the MI flying wires at 1:07 PM. At 2:58 PM, Operations reported that MI was still aborting after transfers of antiprotons, though not quite as often as before. RF experts reported that they had a fix, but it would mean 30 minutes of downtime. This work will be scheduled for Thursday. Operations reported at 3:58 PM that the Recycler had stashed antiprotons six times during the day shift. At 6:59 PM, KRF5 tripped off. It reset. Operations reported at 11:59 PM that the Recycler had stashed five times during the evening shift. Thursday March 27 The midnight shift began with Operations monitoring store 6007 (73.89E30) and the stash (313.8E10), with Pbar stacking (15.9E10), and with NuMI and BNB taking beam. At 12:14 AM, a Pbar Debuncher vacuum pump (IP712) in the AP2 transfer line tripped off for the first of five times in about two hours. Operators reset the pump four times and then left it off after its last trip. At 2:24 AM, a Pbar Debuncher vacuum pump (IP403) tripped off. It reset. Operations terminated store 6007 at 4:03 AM. Operations put the TeV into shot setup at 4:15 AM. At 4:27 AM, a TeV separator at sector A17 sparked during the reverse proton injection. At 5:17 AM, KRF5 tripped off on a LCW flow indication. It reset. Operations established store 6008 at 5:54 AM with an initial luminosity of 271.21E30. Operations reported at 7:49 AM that the Recycler had stashed three times during the midnight shift. Recycler experts began a study period at 7:50 AM. Operators prepared the Switchyard (SY) manholes for access at 7:59 AM. Operators began preparing MI for access at 9 AM. The main reason for this access was to complete the required safety system testing. Operations put the Booster into dump mode for sextupole work at 9:03 AM. Operations put Pbar into standby at 9:05 AM. Water experts began their MI heat exchanger flushing at 9:11 AM. At 9:13 AM, the 750keV area buncher tripped off. It reset. At 9:19 AM, LRF2 tripped off. It reset. Booster experts completed their sextupole work. Operators turned off the Booster beam and began preparing the area for access at 9:19 AM. At 9:42 AM, KRF4 tripped off. It reset. The interlock experts reported at 9:47 AM that they had begun the MI safety system testing. At 9:53 AM, a MI expert reported that the pond water pump at MI-30 was shut off due to a leak. At 10:03 AM, a Booster RF station (BRF10) tripped off. It reset. The Neutron Therapy Facility (NTF) reported at 10:30 AM that they had completed treatment on their last patient for the day. Operators began preparing Linac for access at 10:33 AM. Pbar experts reported at 10:42 AM that they were turning off the lithium lens LCW system to replace a turbine. Operations reported at 11:25 AM that the MI interlock “7A” had a problem and the interlock experts were working on it. Power supply experts reported at 11:34 AM that they had repaired a Booster supply (B:MI8BND). Operations reported at 11:49 AM that Preaccelerator experts accessed the I- Source to inspect its generator brushes. They came out of access 10 minutes later. Linac and Booster were out of access and were turned on by 12:08 PM. A Booster kicker expert reported at 12:10 PM that he had completed his work on MP02. At 12:34 PM, Operations reported that MI8BND would not turn on. Experts investigated. Operations reported at 12:42 PM that interlock experts had completed the MI safety system tests. Operators began the MI turn on. At 1:15 PM, LRF2 tripped off. It reset. NuMI reported that the scheduled MINOS power outage had ended and they began a 30-minute calibration run at 2:38 PM. Power supply experts reported at 3:52 PM that they had completed their repairs on B:MI8BND. Operations resumed sending beam to Pbar, BNB, and NuMI at 3:55 PM. At 4:32 PM, a TeV RF station (TRF1) tripped off on a ground fault indication for its water heaters. This station will be turned back on after the store ends. At 4:51 PM, a Pbar Accumulator RF station (ARF1) tripped off. It reset. At 5 PM, CDF experimenters lowered the high voltage for their detector. At some later time they brought their detector back online. At 5:38 PM, KRF3 tripped off. It reset. At 8:39 PM, KRF2 tripped off. It reset. At 9:15 PM, BRF11 tripped off. It reset. At 9:17 PM, LRF3 tripped off. It reset. Operations reported at 11:59 PM that the Recycler had stashed five times during the evening shift. Friday March 28 The midnight shift began with Operations monitoring store 6008 (56.46E30) and the stash (231.2E10), with Pbar stacking (21.2E10), and with NuMI and BNB taking beam. At 12:22 AM, a TeV octupole focusing power supply (T:OF) tripped off. At 1:39 AM, a Pbar Debuncher kicker (D:IKIK) tripped off. This caused a beam position problem in AP0 that stopped stacking. The kicker would not reset. Operations called in an expert. Operations put Pbar in standby mode at 2:26 AM. At 4:29 AM, KRF2 tripped off and would not reset. Operations contacted a Linac expert who helped operators identify that a relay had failed. The expert said he would come in to make repairs. A Pbar expert reported at 7:16 AM that D:IKIK was repaired. Operations reported at 7:59 AM that the Recycler had stashed once during the midnight shift. The Plans for Friday and the Weekend The plans for today are to terminate store 6008 around 9 AM to let CDF access and make a needed two-hour repair. D0 will also access to perform a couple of small jobs. For the rest of the day and weekend normal stacking, stashing, and storing will resume. |
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