Difference between revisions of "TAGH LG inspection"
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Since ELJEN delivered 14 counters more than the ordered 260 counters and since we will need less than 245 counters for any considered option, there are sufficient counters of all sizes. | Since ELJEN delivered 14 counters more than the ordered 260 counters and since we will need less than 245 counters for any considered option, there are sufficient counters of all sizes. | ||
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| + | See inspection results in [[Media:TAGH_counter_assembly.xlsx Counter assembly spreadsheet]]. | ||
Revision as of 17:07, 13 October 2013
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| 17 counters surveyed by the JLAB Survey and Alignment Group. | All other counters visually inspected and checked for rough alignment at CUA |
Light guides (LG) and scintillators (SC) were produced by ELJEN, the light guides have a 3 mm deep and (mostly) 6 mm wide slot on one end, in which the scintillators have been glued. The slot width is 6 mm for the 8-mm, 10-mm, 16-mm, and 21-mm counters, and the smaller dimension for the other counters (3 mm, 4 mm, 5 mm).
We required the center positioning of SC on the LG to be better than 0.25 mm and the angular alignment to be better than 2 deg. for the wider scintillators (> 5 mm) and 1 deg. for the thinner ones. Based on precision tests of 17 counters by the JLab Survey and Alignment Group, these requirements were met by ELJEN. All counter but the 17 inspected at JLab were visually inspected at CUA. Alignment has been roughly checked by placing the counter on a mm-grid paper. Visual inspection of the SC and LG surfaces showed that 29 scintillators had some glue on the top surface, 13 SCs and 2 LGs have tiny scratches or dents, for 11 counters the glue joint shows small bubbles at corners, 22 glue joints are slightly cloudy (not completely translucent) whereas 4 joints are very cloudy (these counters cannot be used).
Since ELJEN delivered 14 counters more than the ordered 260 counters and since we will need less than 245 counters for any considered option, there are sufficient counters of all sizes.
See inspection results in Media:TAGH_counter_assembly.xlsx Counter assembly spreadsheet.
