CAT Chat Minutes

February 13, 1998

Issues that require action and/or follow-up

1. Tuesday's start up delay was really a problem for our users. We usually have new users on Tuesday, and when we have a late start, we end up staying well into the night with them. Does this have something to do with the fill at 1600 and 2000?

No. The problem was in restoring the storage ring operations. We encountered numerous faults soon after 3:30 p.m.

2. The Control Room took away gap control. When they do this, we do not run. What led to this?

We are fully aware of the fact that being able to control the ID gap at all times is an essential part of the operation of each beamline. We will intentionally take away the ID control only when really warranted. In this particular case, we were losing communication with certain IOCs, and the global feedback process stopped working. As a result, the beam had drifted away and was close to the BPLD trip points. By taking away the gap control and opening the devices, we could have prevented the beam from tripping due to BPLDs. However even before we could attempt to do this, we lost the beam.

3. Can more gravel be added to the 435 auxiliary parking lot? Will it ever be paved?

The gravel should have been added last summer to have a useful lot. We will do this when we have better weather. The lot was meant to be paved, but there is an approval requirement on a wetland issue. The longer range plan is to expand this lot or to have a drive through to the next parking lot.

4. What is the plan for the 1998-2 SOM?

We have received two requests for 1998-2 that are very similar to 1998-1 SOM. We will let you know the details next week.

5. Can the ATM in the 401 lobby be stocked with $5.00 bills in order to be compatible with the vending machines? Or could a change machine that will take $10.00 bills be put in where the vending machines are located?

We will check into this.

6. Getting food after hours is a real problem for our users. Could there be an after hours snack bar, or at least somewhere they could go to get something warm, or something other than food that has been sitting around a long time? Pizza or bagels would be okay.

We will check into this.

7. When steering corrections are being done, the announcements of these are not consistent. It is also difficult to see when the correction is complete. It may be that the person who requests the correction does not know when the correction has occurred.

If you have a machine status screen, you should be able to tell when the steering is complete. All steering is done in small steps, not the full amount at one time. When the operator starts the steering, the orbit correction flag is set. However, in the middle of the steering, if the operator finds some other problems and he stops steering, the flag is removed. At this time, the steering flag truly reflects only when the correctors are actively applying corrections to steer for a particular beamline.

8. Has anyone noticed any difference in beam when corrections are made?

The general consensus was no. In spite of that, we will make certain that the announcements of orbit corrections continue for another month.

9. Has anyone considered providing an ice machine for users?

Yes, Bruce Glagola is working on this with suggestions from the SBC CAT director.

Information/Follow-up Items

APS Operational Status Update

Shielding verification had been scheduled for Tuesday for 6-ID. Vacuum problems were encountered that forced the verification to take longer than expected. Storage ring lattice problems also had to be analyzed, which further delayed the beam back to users. Even more problems were encountered when the singlet SOM was begun on Wednesday. The resulting beam instabilities will limit the maximum fill current for the duration of SOM. Although studies had been done, not enough experience had been gained in understanding all of the issues with this operating mode with the small aperture chamber. During the next studies period, additional studies will be done to improve storage ring performance in this mode.

Monday 2-16 at 0800, we go into a scheduled maintenance period.


CAT Chat was preceded by a short good-bye party for Panayotis (Joe) Georgopoulos, who will be leaving DND Cat as director. He has taken another job but will still keep an interest in beamlines at the APS.

Feb. 21, 1998, there will be a power shutdown for switch gear maintenance of Sector 4 -8. If you will need extension cords, see your FCs Kevin Beyer and Bill Wesolowski for these.

May 2, 1998, there will be a power shutdown of ANL 138 kV feed for ~ 4 hours.

The x 4-0101 will be carried 24 hours during the maintenance period starting at the end of this run. You can reach a FC for emergency purposes at this number. All other calls should go to your FC during normal working hours.