Danny Sellers, LLO Laser Safety Officer, unplugged and locked out the PSL HPO diode box power supplies to prevent the accidental activation of the High Power Oscillator.
See photo. The appropriate laser safety documentation concerning the operation of the PSL is being reviewed and updated to reflect the implementation of this new administrative/ engineering control
Note: Having the HPO diode box power supplies off does not interfere in the operation of the 35W Front End laser.
Also note that LHO made the same change today.
The adding the capability to lock out the pump diodes for the HPO is an important change in operational configuration and how we operate the sites' PSLs. For the record, this is the path followed at LHO to investigate the possibility of an engineering control (the physical locking out of power to the pump diodes), the installation of the control , and the communication with our sister site.
1. Investigation of the way to disable power to the pump diodes and to determine the effect on auxilliary systems, e.g., FE (front-end monitors and coputer controlled interlocks).
LHO WORK PERMIT #5320
Date: Wed Jul 1 11:19:11 PDT 2015
Serial number: 5320
Task leader: Jason Oberling
People performing work: Jason, Rick
Facility: LHO
A lock and tag will not be used.
Period of Activity: 7/1/2015 - 7/1/2015
Area of Activity: H1 PSL, Laser Diode Room
Hazards:
Activity: In light of the event last week at LLO, to avoid accidental turning on of the PSL High Power Oscillator (HPO) we are going to test turning off the HPO diode box power supplies to see if the Front End (FE) still runs. The laser may trip during this test. In discussion with AEI Hanover, who has been talking with NeoLase, we have been told that this should be possible.
2. Announcement to the community of a change in configuration, email:
| Subject: | PSL HPO Diode Box Power Supplies Locked Out |
|---|---|
| Date: | Wed, 01 Jul 2015 12:58:38 -0700 |
| From: | Jason Oberling <oberling_j@ligo-wa.caltech.edu> |
| To: | lho all <lho-all@ligo-wa.caltech.edu> |
FYI for all:
I have turned off, unplugged, and locked out the H1 PSL HPO diode box power supplies. This is to prevent the accidental turning on of the HPO, and does not interfere with the operation of the 35W Front End laser. Lockout IDs are 3986 and 3770. If for some reason access to these power supplies is needed/desired, come see me.
Jason
3. Communication of change and status to a broader group; in particular, our LLO colleagues:
| Subject: | H1 PSL HPO diode power supplies turned off and locked out |
|---|---|
| Date: | Wed, 01 Jul 2015 13:04:59 -0700 |
| From: | Jason Oberling <oberling_j@ligo-wa.caltech.edu> |
| To: | lsc-psl@ligo.org, Janeen Romie <janeen@ligo-la.caltech.edu>, Richard Oram <roram@ligo-la.caltech.edu> |
| CC: | fred.raab@ligo.org |
As the subject says, I have turned off, unplugged and locked out the PSL HPO diode box power supplies to prevent the accidental turning on of the HPO. Benno reported in this morning's PSL meeting that this should be possible and I have confirmed: having the HPO diode box power supplies off does not interfere in the operation of the 35W Front End laser. I recommend LLO implement this as soon as they are able.
Jason