Accelerator Update - July 7 - July 9
The integrated luminosity for last week was 2719.1 nb-1.
At 9:50 AM, a Pbar Debuncher power supply (D:VT925) stopped putting out current, which delayed the shot setup. Operators contacted an expert who had the supply operating normally by 10:13 AM.
Operations reported seeing a possible correlation, at 1:15 PM, between the rise in outside temperatures and Booster MH2 power supply problems. Its regulation suffered whenever line voltage drooped.
The Main Injector (MI) power supplies at MI-10 tripped off at 9:44 PM. Operators called an expert who instructed the operators to check certain systems. Nothing of any significance was found. Stacking resumed at 10:05 PM.
A cryo system expert investigated the TeV sector C3 wet engine, at 11:19 PM, and confirmed it would not last much longer. If this engine was turned off or tripped off the store would be lost. They were devising a plan to try using a JT valve to keep the flow of helium to the cryo magnets when a power glitch, at 11:20 PM, caused the store to abort. Too many things tripped off to bother naming. Everything was, eventually, turned back on.
The Collider Detector Facility (CDF) and D-zero (D0) experiments accessed their collision halls at 11:36 PM.
Pbar resumed stacking at 11:42 PM.
Work on the TeV sector C3 wet engine began at 11:50 PM.
Tuesday July 8
D0 came out of access at 12:31 AM, and CDF came out an hour later.
The cryo techs reported, at 2 AM, that the C3 wet engine needed its flywheel changed. They completed their work at 3:14 AM.
Operations put the TeV through a dry squeeze and then began shot setup at 3:49 AM.
Operations established store 2770 at 6 AM. Its initial luminosity was 32.37E30. Pbar resumed stacking.
A Booster RF station (BRF9) tripped off seven times between 4:22 PM and 5:43 PM. Operators talked with an expert who advised lowering the modulator's voltage; this stopped the sparking.
MiniBooNE asked to have their beam stopped, at 6:34 PM, so AC techs could repair their detector's air conditioning. They were back on line at 8 PM.
A Booster device (B:CEPSE2) tripped off at 8:42 PM. Operators investigated, found and changed a bad MADC chassis.
Pbar resumed stacking at 9:28 PM.
A Booster kicker (MKS03) tripped off at 9:31 PM. Operations called in two experts who had the kicker working by 11 PM.
At 10:49 PM, a Booster device (B:CEPSE2) tripped again, this time due to power supply fault indication.
Booster suffered from a flurry of RF problems at 11 PM. All the RF stations were back on by 11:19 PM except for station 13. An expert, called in earlier, arrived and began investigations and possible repairs.
Pbar resumed stacking at 11:40 PM.
Wednesday July 9
A TeV sector A2 wet engine tripped off at 12:21 AM, due to a gas bottle going empty that operated the engine's brake. A cryo tech changed out the bottle.
The expert investigating the BRF13 problems stated, at 12:30 AM, that the station's modulator needed changing. The station was bypassed and the repair was put off until a later date.
Operations terminated store 2770 at 2:05 AM.
The Switchyard expert finished his study at 2:14 AM.
Operations put the TeV through a dry squeeze at 2:53 AM and then into shot setup at 3:23 AM.
Operations established store 2772 at 7 AM with an initial luminosity of 33.38E30. Pbar resumed stacking.
Comments and Suggestions
|last modified 7/9/2003 email Fermilab|