CAT Chat Minutes

May 21, 1999

Information/Follow-up items

1. During the fill-on-fill with shutters open, will we be able to continue scanning the undulator gaps?

At the present time, we expect that undulator scans will be allowed to continue. The impact will be further investigated during the machine studies. We will let you know if the interaction with injection is significant enough to require suspending the undulator scans.

2. Is there a reason why we need two fills per day?

Operation with singlets results in a higher current per bunch, causing a decrease in the stored beam lifetime. Therefore, we have to refill twice a day. This does result in a higher average current overall.

3. While working on our beamline, we noticed the status of the shutter enable and the indicators for front-end shutter positions changing state. We use some of these signals as inputs into our beamline control system. Since we are in scheduled maintenance, what is occurring?

During this shutdown, ACIS validation is occurring in the storage ring. Part of the validation requires the front-end shutters be cycled to ensure that the system response is correct. There are multiple PVs available, which can be used to disable control functions during shutdown periods. Let us know if you need help implementing such a fix.

4. When does the liquid nitrogen dewar filling service begin?

We will resume filling the dewars next Wednesday, May 26.

User Operations

Beginning June 2, at 8:00 am, user operations will resume with fill on fill with shutters open. Blanking signals will be available next week to test your electronics. We will provide more detailed information on these signals next week. If the beam is lost, shutter will be closed prior to reinjection. The standard fill pattern will be singlets with two fills per day, nominally at 0800 and 2000 hours.

During the scheduled maintenance, we had two failures in the machine status link chassis. If you experience a fault in this chassis, please contact M. Ramanathan at x-3773.

General Information

General Facility Maintenance - A number of maintenance personnel will be in the area repairing parking lots, replacing cracked laboratory sinks, sealing LOM door leaks, and performing numerous other minor repairs that have been reported. Please keep your floor coordinator informed of other problems that are found.