CAT Chat Minutes

February 25, 2000

Information and Follow-up Items

1. We have heard the acronym ACIS used frequently when the storage ring is discussed. What does it stand for?

ACIS stands for Access Control Interlock System, which is the engineered safety system for all accelerator enclosures, akin to the Personnel Safety System (PSS) for the beamlines.

2. Has their been any attempt to do the two minute top-up injections based on a fixed timing standard?

Not at this time. The accelerator functions are synchronized to multiple sources, e.g. power line, fixed oscillators, etc. We will need to review all of these timing interactions to see what could be done.

3. Can PA announcements be made to notify us when either the timing tests or regular top-up begin during the upcoming top-up studies period?

Yes. We will make an annoucement over the PA.

4. During shutdown periods, is it possible to provide top-up injection pulse and gate pulses even though no beam is in the machine, especially during the two-day studies period?

We will need to look into the logic which generates these signals to see what it will take to continue generating these pulses during non-user periods.

5. After a recent beam dump and refill, our users discovered a loss in their intensity. We traced it to an ID gap error due to the mechanical gear backlash in the ID. Is there a way that the IDs, when they are commanded to close after a fill, be closed to a smaller gap and then opened to the desired gap?

The close command is an automated global command affecting all the devices. At the present time, there is no way of performing the action that you are requesting. When the ID position encoder calibrations are done, the IDs are calibrated approaching from the open position. However, if it is desired, the calibrations can be performed from the opposite direction. This may be a solution for your specific case.

User Operations

The overall efficiency for the run thus far is about 95%. Several blocks of downtime occurred primarily due to an ACIS trip, an rf trip, and several power glitches.

A proposed top-up schedule was presented to the group. The user top-up studies take place starting on Monday, February 28 at 0800 hours and will last 24 hours. Three short (5 minute) periods will be available in order to test triggering with the injection magnets pulsing at a 2Hz rate. A cat-net message will be sent with the schedule and listing the critical PVs for top-up. The users run will resume Wednesday, March 1 at 0800 hours.

General Information

Visitors from the Shanghai National Synchrotron Radiation Center (SSRF) will be here next week for discussions with APS personnel. A seminar on the Status of the SSRF Project Linac and Booster will be presented on Tuesday, February 29, at 1:00 pm in Room A1100. Anyone who is interested is welcome to attend.

The Metrology Workshop will be held here at the APS on March 16-17, 2000. The registration deadline is March 1. This particular workshop is intended to gather diverse communities in the areas of: metrology, instrument developers and vendors, mirror manufacturers, x-ray and neutron optics scientists, and end users. Vendor exhibits will also be displayed in the APS gallery. Registration and further information can be found at