Repairing of lead glass modules

Disassemble Lead Glass Module

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  Fig. 1 Lead glass module: Lead glass block wrapped with Al mylar. PMT housing is attached to the block using steel strap assembly.

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  Fig. 2 Unscrew flange from the PMT side

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  Fig. 3 Remove steel strap assembly

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  Fig. 4 Remove silicon cookie from the PMT side of the glass bar

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  Fig. 5 Remove wrapping from the module

Lead glass characteristics:

Lead glass length: 45 cm

Silicon cookie width: 2 mm

Light guide: length 2 inches (5.08 cm)

             diameter D = 1.25 inches

PMT length: 10 cm ( + 9 mm including pins)

Base length: 17 cm

Total length: 45 + 5 + 10 + 17 = 77 cm

Step 1: Inspect lead glass module (see corresponding section) to make sure the the module has to be disassembled.

Step 2. Loose screws on the flange attached to the PMT housing

Step 3. Remove steel strap assembly holding together the PMT housing and lead glass block

Step 4. Remove silicon cookie (note the cookie may stick to the glass block; use a wood stick to scrub if needed)

Step 5. Remove aluminized mylar wrapped around the glass block. Note, the Al Mylar thickness is about 13 um; the Mylar joint is positioned under the strap (no sticky tape is used on the joint)