Difference between revisions of "Visual inspection"
From GlueXWiki
(→Possible issues with lead glass module) |
(→Possible issues with lead glass module) |
||
| Line 20: | Line 20: | ||
# Broken lead glass, see Fig. 1 (module taken from the FCAL prototype) | # Broken lead glass, see Fig. 1 (module taken from the FCAL prototype) | ||
| − | #* | + | #* some problems can be seen by looking on the lead glass block from the side opposite to the PMT |
#* lead glass module has to be disassembled; the glass block has to be replaced. | #* lead glass module has to be disassembled; the glass block has to be replaced. | ||
# Issues with wrapping: | # Issues with wrapping: | ||
Revision as of 11:11, 18 October 2022
Fig. 1 Broken glass
Fig. 2 Wrapping issue: teared Aluminized mylar, can be fixed without disassembling module
Fig. 3 Wrapping issue: Al layer peeled off
Fig. 4 Wrapping issue: Al layer peeled off, teared wrapping foil
Fig. 5 Damaged PMT
Fig. 6 Colored lead glass module, possible radiation damage issue. Can be seen without removing steel flange.
Fig. 7 Colored lead glass module
Possible issues with lead glass module
- Broken lead glass, see Fig. 1 (module taken from the FCAL prototype)
- some problems can be seen by looking on the lead glass block from the side opposite to the PMT
- lead glass module has to be disassembled; the glass block has to be replaced.
- Issues with wrapping:
- small damages (holes) in the Aluminized mylar, see Fig. 2. This can be fixed by using Al sticky tape, thickness < 20 um
- Aluminum layer in the wrapping foil peels off or adheres to the glass block (penetrates into the block):
- Fig. 3 and Fig. 4: Aluminum layer peeled off resulting in some transparent holes in wrapping.
- Recommend to disassemble and re-wrap the lead glass block
- Issues with Silicon cookies and PMT
- Inspect optical coupling of the glass block and the PMT by look inside the crystal from the side opposite to the PMT
- Possible damages of the PMT during deinstallation (see Fig. 5)
