300 BeV Energy Achieved July 16th
The severe electrical storms that broke over Northern Illinois on Friday, July 14th were a serious distraction for the NAL Accelerator Section crews that were tuning the machine on a 300 BeV ramp for the first time. The system tripped off four times on Friday night due to the turbulence. Each time, the painstaking operations were involuntarily interrupted and resumed. On Saturday morning, replacement of a magnet halted progress for several hours. But, in spite of all delays, efforts continued through Saturday and during the day on Sunday, July 16th.
Good beam on a 100 BeV ramp came Sunday afternoon; the ramp was raised to 300 BeV at 8:35 p.m. A satisfactory coasting beam was achieved by 9:10 p.m. Exactly two minutes later, after the radio frequency voltage had been turned on, acceleration reached 300 billion electron volts.
Except for coping with the effects of the natural phenomena outdoors, the 300 BeV occurrence came as a methodical, step-by-step achievement on the shift led by Jon Sauer as Operations Chief. Keith Meisner was chief accelerator operator, assisted by Barry Bames, Grover McIntyre and R. Webber. Bob Angstadt carried out the Main Ring electrical function with Vie Garzotto and F. Johns on on Main Ring mechanical. John Benolken served as Duty Assistant. Dick Cassel performed his magic calculations on the power supplies during Sunday afternoon operations. Stan Tawzer and Jim Griffin handled R.F. duties. A few other interested persons came and went from the control room area in the course of the hours of the decisive run while the machine and the crew performed well, again.
Preparations were underway immediately to extract the 300 BeV protons from the Main Ring and route them to the 30-inch Bubble Chamber to carry out the first experiment at the higher energy. The crews, still plagued with such distractions as a tornado warning evacuation on Monday night, July 17th, and power outages beyond their control attained some 300 BeV extraction success by Wednesday, July 19th.
During the tests, engineers and technicians from Commonwealth Edison stood by to monitor the effect of the higher energy accelerator operation on Commonwealth Edison's power distribution system. The new high in acceleration came as one of three fronts being attacked in the Accelerator Section - namely, continued improvement in the general operation of the machine, developing intensity, and achieving slow extraction. Efforts in the Section rotate from one phase to another, in addition to providing beam to the Internal Target and Neutrino laboratory experiments. With a total of 41 power supplies now installed and with operation increasingly reliable, the try for 300 BeV was a logical progression. Increased intensity in the Main Ring to match intensity levels achieved regularly in the Linac and the Booster, and slow extraction are expected to reach satisfactory levels in the near future.
Dr. Boyce McDaniel, head of the Accelerator Section, commented on the 300 BeV event, "We had expected that we would achieve higher energy without much difficulty, but we were still very pleased when it happened."