CAT Chat Minutes

April 15, 2002


Information and Follow-up Items

1. On April 8, the beam became unstable. The problem had been identified on the tv monitors, but no announcement was made. What caused this problem and why was an announcement not made?

The reason for the beam motion was an error in the recently rewritten procedure. This procedure required rework as a result of the software changes associated with increasing the orbit correction update rate from 0.4 Hz to 1.5 Hz. This has been corrected. In the confusion of trying to identify and correct the problem, no announcement was made. We will continue to work on improving notifications in such situation.

2. Recently, when I needed items from the stockroom, I was unable to purchase supplies because the bar code on my badge could not be read. In the past, we were able to punch in the badge number for stockroom issues. Why has the procedure changed?

The losses in the stockroom have been steadily increasing due to incorrectly entered badge numbers and/or charge codes. The card readers were added to minimize the losses and to improve tracking of stockrooom issues. If your badge is unreadable, the user office will issue you a new one.

3. We are having problems operating the gap control of the undulator slowly to synchronize it with our data collection. Can the speed be reduced further?

At the current time the slowest speed for the undulator is about 6 microns/sec. The device can be slowed further, but this change will require more investigation to avoid resonances. If you need to do synchronous scanning at speeds less than 5 microns/sec, it is better to do point scans with the ID deadband of approximately 5 microns.


User Operations

The machine has been running well with availability for the run at approximately 97%. Earlier this week we had several problems, primarily with power supplies and rf trips.

We are in a 48-hour machine studies ending on April 17 at 0800. User operation with low emittance lattice top up with a hybrid fill containing a singlet will start on Wednesday and will continue until April 23. Beginning April 23 at 1600 hours, the hybrid fill pattern will be switched to a triplet with non top-up, high emittance lattice.


General Information

During this coming maintenance period, the low temperature hot water system will be shut down and the gaskets, which have been prone to leaking, will be replaced. The system will be drained and contractor personnel will be making the repairs. A schedule will be available soon, and the floor coordinators will work with each of the sector personnel to ensure that equipment is protected and that the contractors have access to the overhead piping. If you have any further questions, please contact your floor coordinator.

The user staging area, occupying an area of 20 by 20 feet, has been prepared at Sector 30. It will be available for short-term storage for periods no longer than 7 days. Kevin Beyer will be the contact person to arrange using the staging area.

The April TWG meeting will be held Thursday, April 18 in Bldg. 401, room. A1100. Glenn Decker will give a presentation on beam stability.


Operation of Beamlines

The formal documents that govern beamline operation are the Commissioning Activity Approval (CAA) form and the Experimental Safety Approval Form (ESAF). At this stage of the APS development, most beamlines have completed their initial commissioning activities. Beamlines, which are submitting ESAFs for their activities, are considered from the facility operations standpoint as Operational. In this context, the term "Operational" denotes that CAA forms are no longer required for defining operational limits and DOES NOT reflect a beamline's status for accepting proposals under the Independent Investigator (II) program. We will be updating all of the beamlines that are still operating under a CAA form, but using the ESAFs. The affected beamline representatives will receive an e-mail when this is done. The status of each beamline is listed on the APS Beamline Station Operation Limits Information web page at: