CAT Chat Minutes

January 28, 2000

User Operations

Rod presented viewgraphs of the seven-day storage ring availability to the group. The causes for the trips that occurred over the past two weeks are still being investigated. This past Tuesday, on January 25th, the 8-hr machine studies period was used to perform work on the main dipole power supply and the RF system.

Next Monday, January 31st, machine studies will begin at 0800 hours and continue through Wednesday, February 2, 0800 hours. Shielding verification will take place for 4-ID-B on Tuesday, February 1st from 0700 through 1300 hours. Storage ring shutter permit will be available. Beam will be stored at 10mA for 3-hrs and at 30mA for 3-hrs.

One of the storage ring trips was attributed to a PSS trip at 11-ID. We were able to identify the problem to a manual door. The manual door was not latched both on the top and the bottom and this allowed the door to be jarred, either by accidental contact or pressure from the pneumatically actuated door. The small motion was sensed by one of the two door switches, which sent the signal to the PSS processor that the door was not closed. Since the shutter for the beamline was open, the PSS reacted with the correct response and aborted the stored beam. The PSS panel at the beamline indicated that the manual door was neither open nor closed (both LEDs were off).

To prevent this type of beam dump from occurring in the future, please ensure that both latches are engaged on manual doors. Also notify your floor coordinator if you notice any ambiguous indications on the PSS panels (either both LEDs on or both off). These are abnormal conditions and will prevent you from operating the beamline