User name Charles Hyde-Wright
Log entry time 11:37:36 on February 1,2002
Entry number 81469
Last evening, we moved HRS-L from 14.57 deg to 4A endpoint kinematics
40.97 deg. After brief endpoint runs we moved HRS-L to
42.58 deg for production running.
Both moves were done without visual inspection in the hall.
Probably between 40.97 and 42.589 we pushed the concrete stop
on the floor and snagged a cable bundle. This bundle runs
from HRS photon arm, in front of the front bogies and to the
RCS electronics hut. The bundle consists of on HV cable, two
high quality signal cables and aprox 4 Rg-58.
The HV and 3/4 RG58 cables jammed under the guard plate
surrounding the bogie on the large angle side of the spectrometer.
The cables were stretched very tight (wrapping around a beam
dump support post). The HV set point of 500 V did not trip.
The HV cable drives a PMT monitoring the gain monitor laser
on photon arm. The signal cables are cosmic trigger, laser trig?, etc.
S0 trigger cable was also coiled dangerously close to middle bogies,
At 10:30 we went in to install post radiator in front of sweep magnet.
Could not pull cables free of bogie. Cut cables, and pulled cables
free during and after motion from 42.58 to 40.97 degrees.
Beam restore 11:30
Do not make large angle changes without visual inspection.