CAT Chat Minutes

September 24, 2001

 

Information/Follow-up Items

What radiation levels can we expect with high current operation?

Measurements done with passive dosimeters on the shielding wall close to the FOE show most locations with zero level gamma and neutron dose rates. Some dosimeters indicate an above background neutron dose, but these readings do not indicate any consistent pattern with FOE locations and are a result of subtle changes in the loss patterns from run to run. The dose rates in other beamlines locations are monitored routinely and are well within our prescribed limits. If we double the stored beam current, all of these levels are expected to double. These levels would still be well within the limits, but we plan to perform extensive surveys as we begin high current operation.

 

User Operations

Currently, we are in the last week of operations for Operating Cycle 2001-3. Three faults occurred this past week, all from rad monitor trips. An 8-hour machine intervention/studies period will start on Tuesday, September 25 beginning at 0800 hours. The last week of the run will continue using hybrid fill with top-up. This mode will be a standard 3 + 8 7.

Overall, availability for the present run is approaching 96%. During this run, nearly 1200 hours of beam time will have been delivered. Scheduled maintenance will begin on Sunday, September 30 and will last approximately 4 weeks.

On Sunday, September 30, machine studies are planned to investigate storage ring operation at currents up to 200 mA. We are looking towards the future for operation at a higher current. All systems appear to be working well at the 100 mA level and the storage ring has been designed for higher current. The front-end current limit is being investigated. In the near future, we will be requesting the CATs to identify any apparent limitations in their own beamlines.

The APS Run Fiscal Year 2001 Operation Statistics, to date, are shown below:

Run

Availability

MTBF

00-4

95.30%

21.28 hours

01-1

96.54%

28.37 hours

01-2

95.51%

33.84 hours

01-3

95.23%

20.65 hours

Total

95.65%

26.04 hours