[Halld-cal] acrylic sheets for Fcal monitoring system

[Elton Smith]

Matt,

We are trying to converge on properties for the acrylic sheet for the 
Fcal monitoring system that is available and affordable.  At first we 
investigated the availability of UVT for two reasons
1) make sure there is good transmittance of the UV laser light
2) this material is environmentally more stable than UV absorbing 
acrylic that yellows over time.

We have had no success with finding sources of UVT acrylic in 1/2" 
thickness without ordering large batches. The UV-violet LED for the 
monitoring system is at 405 nm, which is mostly within the transmission 
window of UV absorbing acrylic. Also the tests in Athens were conducted 
with UV absorbing plastic.  Therefore we are investigating options for 
purchasing UV absorbing 1/2" plastic.

We will also need to adjust the clamps on the panes so that we 
accommodate the use of 4'x8' sheets of material. It is unclear what the 
availability is of larger sheets (e.g. 51"x51", which was used for 
testing in Athens).

Let me know if there are any comments or concerns to this course of action.

Thanks, Elton.

-- 
Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave STE 16
Newport News, VA 23606
(757) 269-7625
(757) 269-6331 fax