Accelerator Update for May 30, 2008 - June 2, 2008

Friday May 30

The day shift began with Operations monitoring Tevatron (TeV) store 6176 (70.6E30) and the Recycler stash (259.2E10), with the Antiproton Source (Pbar) stacking (34.7E10), with the Main Injector, Booster, and Linac operating normally, with the Collider Detector at Fermilab (CDF) and DZero (D0) using the colliding beams, and with the NuMI and SciBooNE / MiniBooNE (BNB) experiments taking beam.

At 10:29 AM, Operations reported that two Linac RF stations were having problems (LRF4 was having a control problem and LRF5 was having a driver screen voltage problem).

At 10:51 AM, Operations reported that the Linac bunch length had grown and the Linac intensity was down a little. Operators investigated.

At 12:58 PM, Operations reported having a problem with a MI-8 transfer line collimator. Experts were investigating.

Linac experts reported at 1:01 PM that they were swapping out the control module for LRF4.

Operations terminated store 6176 at 1:21 PM.

Controls experts reported at 1:23 PM that they were swapping out the MADC for Switchyard (SY) CAMAC crate #60.

At 1:25 PM, a Linac Klystron RF station (KRF4) tripped off. It reset.

Operations put the TeV into shot setup at 1:53 PM.

Operations established store 6177 at 3 PM with an initial luminosity of 225.78E30.

Operations reported at 4 PM that the Recycler had stashed antiprotons once during the day shift.

A Recycler expert reported at 4:26 PM that he would be conducting studies during the next stash.

At 5:29 PM, Operations reported that the NuMI horn #1 expansion tank was not recovering water. Operations contacted experts.

At 6:01 PM, Operations turned off beam to NuMI.

Operations turned off the NuMI beam for an access into their LCW room at 7:05 PM. The experts will try to turn on the second water pump.

At 7:21 PM, a Booster RF station (BRF8) tripped off. It reset.

Operations prepared the NuMI target hall for access at 8:02 PM. NuMI experts reported that turning on the second pump didn’t help. They will enter the target hall and try lowering the spray nozzle.

At 8:39 PM, a TeV correction magnet (T:VB12) tripped off on a quench indication. There was an emittance spike, but the store remained intact.

At 8:46 PM, a MI RF station (MIRF1) tripped off on a supply shunt over-current trip. This station eventually reset.

A NuMI expert reported at 9:13 PM that adjusting the spray nozzles allowed the return water flow to keep up. Operations resumed sending beam to NuMI at 9:22 PM.

At 9:45 PM, a Pbar Debuncher septum (D:ISEPV) tripped off on a ground fault indication. It reset.

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

Saturday May 31

The midnight shift began with Operations monitoring store 6177 (82.73E30) and the stash (270.2E10), with Pbar stacking (26.8E10), and with NuMI and BNB taking beam.

At 12:14 AM, BRF11 tripped off. It reset.

At 1:41 AM, BRF3 tripped off. It reset.

At 2:51 AM, the Linac Klystron Vernier tripped off on a transformer LCW flow fault. It reset.

At 2:59 AM, KRF4 tripped off. It reset.

Operations terminated store 6177 at 3:02 AM.

At 3:28 AM, KRF4 tripped off. It reset.

Operators reported at 3:38 AM that they had changed the regulator for T:VB12.

Operations put the TeV through a dry squeeze at 3:59 AM.

Operations put the TeV into shot setup at 4:23 AM.

At 4:38 AM, Operations reported that with the Time Line Generator (TLG) 2B event, 50-80% of beam was being lost due to a bad tune. Operators loaded new tune setting and everything was back to normal by 4:59 AM.

At 5:27 AM, KRF4 tripped off. It reset.

Operations established store 6179 at 6:07 AM with an initial luminosity of 257.06E30.

At 6:54 AM, KRF4 tripped off. It reset.

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

At 9:18 AM, the Linac Klystron Vernier tripped off on a flow fault. It reset.

At 10:46 AM, KRF4 tripped off. It reset.

At 1:30 PM, CDF and D0 informed Operations that luminosity was drifting. Operators investigated.

At 2:57 PM, Operations reported that the TeV sector C49 separator power supply went erratic for about five minutes and then resumed stable operations. Later, two TeV experts investigated.

At 4:11 PM, the TeV suffered an E1 quench due to a voltage regulation problem with the C49 separator.

At 5:07 PM, Operations reported that the MI beam had been suffering aborts for the last 20 minutes due to bad beam positions. A MI expert recommended operators reboot the MI low level RF system. Operators rebooted the system, but the bad beam positions persisted.

TeV experts reported at 5:25 PM that they had replaced the C49 separator voltage regulator.

At 5:40 PM, Operations reported that NuMI beam was off due to the MI RF problems, which were due to a quadrupole power supply. Operations contacted power supply experts.

At 5:45 PM, a Booster vacuum pump tripped off (B:IPRF17) and caused BRF7 & 8 to also trip off. Everything reset.

Operations reported at 7:42 PM that the MI beam position problems disappeared when the MI was running on a non-NuMI event (29) in the TLG.

Operations started ramping the TeV at 7:56 PM.

Operations reported at 8 PM that the Recycler had stashed seven times during the last 12 hours.

Operations put the TeV through a dry squeeze at 8:12 PM.

At 9:41 PM, Operations had tried to put the TeV through a wet squeeze, but the beam was lost before the ramp began. Operators investigate and discovered that a kill beam command was accidentally given.

At 9:46 PM, KRF4 tripped off. It reset.

A power supply expert reported at 9:49 PM that he was changing out a regulator card for MI quadrupole power supply.

Operations reported at 10:11 PM that they had power cycled the MECAR crate at MI-60 in an effort to fix the MI injector problems. This did not help. Operations contacted an MI expert.

The MI expert reported at 11:02 PM that he thought there was a timing problem. He conferred with the power supply expert who aligned the power supply’s control bit with the ramp reference, which fixed the problem.

At 11:13 PM, cryo system experts at CHL reported an alarm on the TeV sector E4 cold compressor. Experts were called in to replace the compressor’s 24-volt power supply.

Pbar resumed stacking at 11:57 PM.

Sunday June 1

The midnight shift began with Operations monitoring the stash, with Pbar stacking, with NuMI off due to MI problems, and with BNB taking beam.

NuMI resumed taking beam at 12:02 AM.

At 1:23 AM, the Linac Klystron Vernier tripped off on a flow fault. It reset.

At 1:35 AM, the NuMI beam permit tripped off due to a problem with the MIRF gap envelope. It reset.

Operations put the TeV through a dry squeeze at 2:57 AM.

Operations put the TeV through a wet squeeze at 3:48 AM.

Operations put the TeV into shot setup at 4:11 AM.

Operations established store 6184 at 5:52 AM with an initial luminosity of 227.37E30.

Operations reported at 7:54 AM that Pbar had set a New Stacking Record with a rate of 26.91 mA per hour.

Operations reported at 7:59 AM that the Recycler had stashed once during the last 12 hours.

At 10:44 AM, a Pbar Debuncher septum (D:ISEPV) tripped off for the first of two times in three minutes. It reset.

At 11:13 AM, KRF4 tripped off. It reset.

At 2:06 PM, Operations reported that the I- Source’s high voltage was “acting up.”

At 2:20 PM, KRF4 tripped off. It reset.

At 2:52 PM, LRF4 tripped off. It reset.

At 3:13 PM, the Pbar VSA stopped communicating while stashing. Operators halted the stash. The VSA starting operating normally two minutes later.

Operations terminated store 6184 at 4:08 PM.

Operations put the TeV into shot setup at 4:19 PM.

At 4:47 PM, KRF4 tripped off for the first of two times in about 40 minutes. It reset.

At 5:32 PM, KRF7 tripped off. It reset.

At 6:28 PM, Operations reported more Pbar VSA problems.

Operations established store 6185 at 6:31 PM with an initial luminosity of 237.37E30.

Operations reported at 8 PM that the Recycler had stashed six times during the last 12 hours.

At 8:55 PM, LRF5 tripped off. It reset

At 9:07 PM, KRF4 tripped off. It reset.

At 9:31 PM, LRF2 tripped off. It reset.

At 10:38 PM, a MI correction magnet power supply (I:H602) tripped off on an overcurrent trip and caused the NuMI beam permit to trip off. Operators changed out the power supply’s regulator.

Operations resumed sending beam to Pbar and NuMI at 11:16 PM.

At 11:35 PM, KRF4 tripped off. It reset.

Monday June 2

The midnight shift began with Operations monitoring store 6185 and the stash, with Pbar stacking, and with NuMI and BNB taking beam.

At 1:31 AM, KRF6 tripped off. It reset.

At 2:47 AM, a TeV RF station (TRF8) tripped off. The luminosity dropped. CDF turned off its detector due to beam in the abort gap.

At 3:40 AM, BRF14 tripped off and would not reset. Operators bypassed the station and brought BRF19 on in its place.

Operations reported at 4:24 AM that they had cleaned out the TeV abort gap. CDF turned its detector back on.

Operations reported at 8 AM that the Recycler had stashed eight times during the last 12 hours.

The Plans for Monday

The plans for today are to terminate store 6185 this morning, let cryo experts work on the TeV sector C4 compressor, and then resume stacking, stashing, and storing.

Accelerator Update Archive

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