• RTV cookie/mold: The 25-cookie mold is finished and looks really nice once the holes are well polished. I gave the mold to Tom and Jeff so they can design a table for cookie production and start it.

 
• Pb-glass radiation damage: David has shown the measurements he has made on the damaged Pb-glass blocks. There is a definite loss of transmission, about a factor 4. He has tried to heal the block with a very well focused UV light beam (100 W UV lamp focused on a ~5 mm diameter area on the block). In an 1 hour time, the block seems to have gained most of his transmission back (~95% of the initial value). This is a very good news. David will investigate on how to cure a whole block with a larger and/or more powerful UV lamp. Bogdan will install a new block in the hall on thursday with different thickness of lucite to study how to avoid the very low energy radiation damage we observed.

 
• Cooling system: Tom will show us the manifold for the 25-block prototype next week, he should be done by then.

 
• Gain monitoring system: Again we discussed what to choose for the gain monitoring system. We settled the design of the titanium flange: 4 symetric tapped holes (8x32).

 
• Parts ordering: The JLab account is not setup yet. Alan is working on making that faster so we can start ordering the parts.

 
• Circuit board: I've asked for 6 circuit boards of the last prototype, so Albert can make sure it is all right and people can train on soldering on them too. The electronics shop can't have it before late this week or next week (some equipment broke and had to be replaced there).

 
• Long Al tube holding system: Jeff has cut a number of tubes and demonstrated he could do it right at ODU for much less money. We can start ordering the raw tubes very soon through JLab so the cutting can start soon.

 
• High voltages: Jack told us that he planned on using 4 racks for the high voltages, 2 of them being used for the patch panels. We will use multiwire cables, with something like ~56 wires by cable. There will be another patch panel on the frame of the calorimeter. We plan on using 'cheap" two-pin connectors to connect to the PMT base. Jack and Eugene will try to find the right connectors (with Bogdan's help).

 
• 9-block prototype: The 9-block protype should be ready in the Moller apparatus this thursday. It will use the Moller DAQ. Alan placed the scintillator and the lucite pieces there too to test them. Those signals are brought back to the counting house.

 
• Pb-glass blocks: The first ~200 blocks were supposed to arrive last friday but will actually arrive at JLab only this friday. For the moment, they will stay in there boxes. As soon as we got the shelves we need, we can store them appropriately (~1 to 2 more weeks).

 
• LED pulser: I will get the LED pulser modified so the pulse frequency will be something like ~30 Hz and not 30 kHz (we can't use it that fast). It can be useful for some tests later.

 
Franck Sabatie - 05/12/1999


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