[dsg-eic_dirc] DIRC laser lab daily operations

[Grzegorz Kalicy]

Hi Marc,

Here is the daily operation description. Let me know if this is what you had in mind or something else should be added.

Cheers,

Greg

"
The DIRC QA lab located in EEL108 will be used to evaluate synthetic fused silica bars received from SLAC for their mechanical and optical quality.
The lab will have four parts:
a) bar cleaning station with:
  1) table for unpacking, chair
  2) temporary storage rack
  3) table for visual inspection, chair
  4) halogen light for visual inspection
b) cleaning station with
  1) table
  2) shallow basin to collect waste water
  3) short-term storage rack
  4) cart with cleaning supplies
c) laser lab in interlocked darkroom with:
  1) optical table with laser setup: HeCd laser, set of standard optics components to guide the laser through bar, photodiodes, multimeter
  2) table or cart with DAQ computer
  3) chair
d) long-term storage: cabinet to store up to 600 bars (17x35x1225 mm each)

Operation:
The bar will be unpacked at the cleaning station (a) and placed into temporary storage.
Next the bar will be inspected for surface damage and pollution using the halogen light.
Bars requiring cleaning will be processed at the cleaning station (b) using either a chemical (acetone or isopropanol) or an abrasive (Hastelite) cleaning method.
The inspected bar is either placed in long-term storage (d) or mounted in holders for easier handling and in a short-term storage rack for processing in the laser lab (c). The bars go to
long-term storage (d) after the laser measurement.
All activities will be performed by a trained expert dressed in protective gear (gloves, mask, goggles, and lab coat)

Bars in the short-term storage rack are moved to the dark room (c).
A single bar is being mounted in the optical setup.
Before the laser is turned on the expert controls the optics of setup, ensures that the laser beam s contained by beam dumps and side panels attached to the optical table to prevent unwanted laser reflections.
The optical quality of the bar end surfaces and bulk material is determined by shining the laser along the long axis of the bar, measuring the effective attenuation length.
The coefficient of total internal reflection of the bar will be determined using the same setup after the bar and mirror are moved to create a different entry angle for the laser on the bar end, creating up to 52 internal reflections.
In both cases the laser intensity is monitored by two diodes.
The measurement is started using a pre-programmed sequence on a DAQ computer.
The trained expert will wear the appropriate laser safety gear (goggles, lab coat).
The presence of the expert inside the laser lab darkroom will be required for placing the bar into the laser, starting the measurements and changing the mirror/bar positions, and may be required for occasional manual measurements.


"
________________________________
From: Marc Mcmullen <mcmullen at jlab.org>
Sent: Monday, September 26, 2022 10:43 AM
To: Grzegorz Kalicy <gkalicy at jlab.org>
Cc: dsg-eic_dirc at jlab.org <dsg-eic_dirc at jlab.org>
Subject: DIRC laser lab daily operations

Hi Greg,

When you have time, can you send over the expected daily operations for the lab.

I'll use this as a template to develop the Task Hazard Analysis.

Also, I need a list of the chemicals needed for cleaning and specific details on the cleaning process you mentioned in the meeting.

We can then plan the space outside the laser controlled area.

Regards,
Marc
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