[Solid_daq] Updates and today's meeting cancelled

[Xiaochao Zheng]

Dear All:

Since JLab is closed today due to snow, I will cancel the EC/DAQ meeting. In the following I will provide a brief update and plan on the EC testing.  Please do give the questions a thought, and feel free to comment:

1) As you recall our next goal is to find faster WLS fibers and improve the light collection. For this we need more fibers (other than Y11) and also scintillator blocks that allow us to embed fibers ourselves.

2) I contacted saint Gobain and am waiting for their quote. I plan to order the BCF91A (slow), BCF20 (fast) and BCF92 (fast), all in 1mm diameter and 3m length with diamond-cutting finish. Unfortunately they require a $500 minimum order per type, so I do not want to order more diameters or more lengths as the moment. The length of 3m is quote long, I will see if we can order 3m, 2m and 1m length that summed to $500 (rather than $500 for each length).

3) Prof. Feng at Shangdong U. will ship a hexagon-shape scintillator block to UVa. The block has 3mm groove in it (the deepest they have).  

4) Valdimir P. from IHEP replied to my email and said that they can provide both hexagon-shape in 20-mm thickness. He asked: 
 - how much scintillators do you need?
 - which size will be preferred?
 - which deep of groove do you need?

I am still thinking about the answer. I propose that we request 6.25-cm-side hexagons, with 10-mm deep grooves (to allow up to 10 turns of WLS fiber), and at least 2 blocks for quality control. One remaining question is the radius of the groove. Should we order 2-3 different radius, or only one for now?  If only one radius, what should it be?

5) At UVa we just moved the whole setup (PMT dark box, electronics, computers) to another lab. The first thing we need to do is to reproduce the results we had in December. This itself might take a couple of days, then we can start testing the new scintillators. The next time we will do the test will be mid Feb. 

Thanks,

Xiaochao

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Associate Professor, Department of Physics, University of Virginia
382 McCormick Rd, Charlottesville, VA 22904
Telephone: (434) 243-4032 (during academic year); or (757) 810-2885 (summer)
Homepage: http://people.virginia.edu/~xz5y/Main.html
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