CAT Chat Minutes

October 3, 1997


Issues that require action and/or follow-up
1. The APS is proposing to run the low-beta mode during user beam time. Why can't Machine Studies time be used to run this low-beta mode?

The machine studies time is used to prepare and/or improve the operation of the storage ring and its injector systems. Time is also spent to ensure that the new conditions will not jeopardize the subsequent user operation. This has been the case for the low-beta studies which have shown that the effects will be minimal. Since for any operating mode, the photon beam characteristics and stability in the beamline are the most critical conditions to be met, the ultimate test is to operate in the user mode. We are planning to run the low-beta tests during shifts originally scheduled for shielding verification. The current plan is to run the tests on October 28 and November 4. There is no shielding verification planned for either of these days, so other operating conditions will be normal.

2. Will you continue to hold some of these SV days back even after most of the verification has been done?

Yes, we will continue to do this for a while. Aside from the occasional shielding verifications that may be required, there may be a need for special beam tests as mentioned above. We have also offered you this time to map apertures. We will inform you of the intended use for these periods as soon as we determine there is a need. If no special requirements are needed, this shift will revert to user operations.

3. What is the standard bunch fill pattern for now?

The standard fill consists of a group of 6 sequential buckets filled for BPM triggering followed by 17 groups of triplets (3 sequential buckets filled) with a spacing of 100 nsec (6 + 17*3). We are currently looking at providing 25 triplets (6 + 25*3) as the standard filling pattern. Better lifetime should result from this operating mode.

5. Some people have experienced non-correctable dead time because of this fill pattern. What can we do?

A paper has been written by Wah Keat Lee and Denny Mills that describes a correction method. It can be found in the Review of Scientific Instruments 63 (1), January 1992, pp. 1225-1228.

6. We had a power outage during this past week. What was the reason?

We found out through testing that some faulty circuits had been supplied in the utility power distribution switch gear. These faulty circuits caused the breakers to trip when we had a communications loss with the monitoring computer. The only way to discover which circuits were faulty was by removing the communication link. The number of faulty circuits was greater than anticipated. The switch gear supplier will replace the faulty circuits. This is currently planned for the December shutdown.

It was again noted during this outage that the cryogenic pumps did not restart after the power went down. The Users need to review whether any other critical components will not come back up after power shutdowns.

7. What about Cardkey access for weekend visitors, particularly students?

The floor coordinators will have some visitor cards available for off-normal hours. The FC can give visitors/students orientation but will not be able to provide a permanent user card until the User Office can issue it. If you are bringing students in on the weekend, they will be your responsibility and must be escorted at all times.

Information/Follow-up Items
Card Key:  The card key system begins Tuesday, October 7, 1997. The procedure for deliveries is essentially no different with Cardkey than it was before. Here is the current procedure for User deliveries:

All deliveries for Users are handled through Steve Downey and the APS stockroom. When freight (i.e., requiring the use of riggers) arrives, the VRC notifies Steve, and he directs the driver to the appropriate location, meets the truck, and arranges for riggers to deliver it to the proper location. He then contacts the User and delivers the freight bill. The "T-run," UPS, and Federal Express all deliver to a central location (for UPS, it is the 431 overhead door at 9:00 am, for Fed-Ex, it is the 401 stockroom, etc.) Deliveries are made to Users from that central location by Steve Downey or Frank Bradbury (who works for PFS but is assigned full-time to the APS).

For deliveries during normal hours - S. Downey receives the call - he allows the delivery person to pass and will direct them to the central pentagon of the LOM. At the central pentagon will be a phone with a complete phone list for the delivery person to contact the recipient of the delivery. If that person cannot be reached, the delivery will be made to the stockroom. Someone there will then make arrangements to deliver the package. After-hours deliveries will go to the Guest House. Someone from there will make the arrangements to deliver the package. Not every reader has a phone at this time. Arrangements are being made to install phones at these doors. Signs with the phone numbers of the User Officer for use during regular hours and the Control Room for off-hours will be posted near the phones. The cylinder areas will be locked and the keys given to the sector people and the control room.


APS Operational Status Update:  We are currently in a maintenance period. We will come back up in two weeks on Monday, October 20, 1997, at 0800 hrs. There will be no shielding verification day on Tuesday, October 21, 1997 as we had indicated on the schedule. It will revert back to User Operations. There will be no interruptions in User Operations for the first week.

T. Rauchas went over the performance numbers for FY '97. See attachment. The goal for FY '98 is to provide 4500 hrs. of User Operations. In the next week or so, we will give you an idea of the types of activities that will be going on during the long maintenance period in November/December.


New Issues from the APS:  In the pursuit of learning about the limits of this machine, we would like to test out a low beta mode.  We are currently running with beta of 11 meters. The lower beta gives you a smaller beam size but a larger divergence. We want to test this mode to learn whether we would be able to do such things as sector-specific low-beta operation. We will use a couple of the Tuesdays that we had set aside for SV and will run this low-beta mode for a couple of hours on those days.


Computers:  Today, October 3, 1997, at 5:00 p.m., Oxygen and Ozone will go down for upgrades. They will be back up sometime Sunday, October 5, in the evening. Please use Phoebus as a time server and name server.

Next week we will make the PV gateway a name server and time server.