ALARA Loss Reduction Intensity reduction before the long
• ALARA Loss Reduction Intensity reduction before the long shutdown: In order to minimize the radiation exposure to the personnel working in the tunnel on our major Booster and Main Injector long shutdown jobs, we will be reducing beam loss levels in the Booster and Main Injector the week before the long shutdown. Monday, July 24, we had another meeting to discuss this in detail, and experts ran some beam reduction tests to see how far we would have to turn down the intensities to meet the beam loss limits. The latest iteration of the plan is as follows. – Step 1: Six days in advance of the long shutdown (08: 00, Tuesday, July 31), we will implement Booster power loss limits as well as limits on Main Injector loss monitors. • Booster power loss limit is ~200 Watts, and no more than 50% of the trip level. • Cut the Main Injector losses in half at I: LI 522 A and I: LI 305 A. – Early tests show that 11 Booster turns (down two turns) will meet this requirement with 4 e 12/pulse, and a stack rate of 16 -17 m. A/hr. • We will maximize stacking, Nu. MI will be off, and the remaining beam will be sent to Mini. Boo. NE and SY 120. – Step 2: Four days in advance of the long shutdown (08: 00, Thursday, August 2), we will implement both Booster and Main Injector power loss limits. • Booster power loss limit of ~200 Watts, and no more than 50% of the trip level. • Main Injector power loss limit of ~140 W (330 KJ as read by I: BEL for a 2. 4 second cycle time). – Early tests show that 9 Booster turns (down two more turns) will meet this requirement with 3. 3 e 12 per pulse, and a stack rate of 14 -15 m. A/hr. – User Priority: If there are questions on how to divide the beam, the priority levels are • Collider Program • Neutrino Program (Nu. MI is off) • SY 120
- Slides: 1