CAT Chat Minutes

August 20, 2002


Information and Follow-up Items

[Correction to last weeks minutes: Plant Facilities is looking at various options to preventing wildlife from shorting out the 13.2 ANL feeder. One of these options is to electrify the fence.]

Will there be any power or water outages during the upcoming shutdown?



1) Switchgear maintenance will be taking place on September 7th and the 14th between 06:00-18:00.

* Switchgear J1 will be down on September 7th. This will affect technical power for the LEUTL, as well as conventional power for the Linac/PAR/LEUTL. Lighting, HVAC, water pumps, and rack power will be affected during this switchgear's maintenance. J2 will affect the Booster dipoles, which will be of little impact to anyone.

* Switchgear J3 will be down on September 14th, and this will affect the Booster quads, and also all of LINAC/PAR technical power (IOC's, water stations, rack power, etc.).

2) For the 14th, the emergency transfer switches will be tested for the APS site, which means a rolling interruption to emergency power across the site. 15 seconds when they are tripped and momentary when they are reset. All systems on emergency power will be affected.

3) The affected 13.2 line that was damaged during the last power outage should be repaired and put back on-line during the maintenance period. An exact date is unknown at this time, and the work should be transparent (no power events should take place). No. All power and water will be up and running throughout the whole run.


The only plans for the outage are to connect Sector 16 to the primary process (de-ionized) water system. The user water systems on emergency power will be affected by item 2 above.

2.A user from PNC-CAT was taking pictures of the beamline. Unfortunately, security came by and interrogation took place. Are we NOT allowed to take pictures of our beamline?

You are allowed to take pictures of your beamline. This was a security error. Security will be contacted so this does not happen again.

3.During this shutdown, will there be security walk-throughs?

Yes. The security walk-throughs will take place Monday through Friday.

4.The distances to the source from the ID BPMs are not indicated on Glen Deckers medm screen. Will these be put on the screen so users can calculate angular changes in the beam?

Glen will be adding these to the screen.

5.Will there be any type of computer network downtime through this shutdown period?

Yes. A few channel access gateways will be upgraded during shutdown. Computer support will inform you in advance of exactly when this will occur.

6.Can ASD mechanical group support the compressed air lines and water lines?

The ASD mechanical group can support this work. This work should be consistent with ANL/APS DavisBacon interpretations.


User Information

Glen Decker presented the overall storage ring current and beamline operations history. Glen indicated availability is ~ 96% for the 12th week of the run. The mean time between failures has been 21.84 hours. Six faults occurred this past week caused by a power breaker trip and a rad monitor trip leading to ~ 5 hours of downtime.

The overall statistics for the run is ~ 97.6% availability with MTBF of 47.05 hours. The FY2002 summary thus far is 1640 scheduled and 1600 delivered hours.

Glen displayed a viewgraph of the comparison between lower emittance vs. lower emittance lattices. The plan is to use the lower emittance lattices during the standard top-up user operation mode on October 15. Lower emittance w/lattice has been tested and is working great. This dispersion is ~ 50% larger in lower emittance. A web page will be updated to display the new procedure. See e-mail from Glen Decker and Louis Emery to CATs indicating how parameters change in the lower emittance lattice.

Currently we are in a 48-hour machine intervention/studies period, which will end August 24 at midnight. At 0800 hours will begin top-up user operation in low emittance mode hybrid fill using a single bunch containing a maximum of 5mA isolated from the remaining bunches by symmetrical 1.59 microseconds gaps. The remaining current is distributed in eight groups of seven consecutive bunches with a maximum current of 12 mA per group and a spacing of 48 nanoseconds between groups, one fill per day.

Yifei Jaski presented viewgraphs on the Replacement for Front End 2nd Photon Shutter. After water leak of PS2 in 6-ID was detected, the PS2 was removed from 6-ID and carefully examined. Cracks are found near the bent areas of the blade and as of now we dont know if the cracks are due to material defects in this particular shutter or due to thermal mechanical fatigue stress. Study is underway to calculate the thermal stress in the bending area and mechanical stress from actuating the shutter. In the meantime, we have to prepare spares for any PS2 failure in different sectors. Currently we only have one PS2 spare blade, which will be installed on 2ID this outage and we are not going to make more hockey-stick-style PS2 due to high cost. We currently have four fixed-mask-style PS2s in fabrication for canted undulator. The question is if the canted undulator type PS2 can be used as a replacement for the existing front end. Careful calculations of the thermal loading indicate that the canted undulator PS2 can be used as a replacement for the existing front end up to a maximum beam current of 180 mA at closed gap.

Mohan Ramanathan presented viewgraphs of data from May 97-04 through August 2002 showing the number of PS2 shutter closures on the BM and ID lines to look for a correlation with the 6ID PS2 water leak. There is no correlation evident as there have been many other PS2s that have been closed a lot more. This may point in the direction of manufacturing defects for 6ID.

Bruce Glagola reminded the group that he would be collecting the number of shifts allocated to experiments on the Experiment Safety Approval Form (ESAF) for reporting to DOE-BES. About a week after this run ends, Bruce will be sending out another list. He will be asking to have the corrections back within one week so we have enough time to prepare the annual report to DOE-BES.