# Presentation: 222534

## ICD Update: January Shutdown Work

**Lee Sawyer**
***On behalf of***
**Andy White, Mark Sosebee, Barry Spurlock, Ted Elzroth **
***(Univ. of Texas – Arlington)*****,**** **
**Qun Yu, Alan Stone, and ibid.**
***(Louisiana Tech Univ.)***

## (Some of) The Cast of Characters

- Mark Sosebee

- Andy
- White

- Qun Yu

## Object of January Shutdown

**Fix Everything!**
**When the ICD-N was installed in Fall, 2001, we knew we had some questionable channels.**
**Other channels weakened or failed since then**
**Both electronics problems (preamp pulser)**
**And PMT or related problems (LED pulser)**
**On the order of 5% dead/bad channels by January**
**Spare motherboards, HV divider cards (“bases”), and replacement drawers were prepared in anticipation of the shutdown.**
**New PMTs ordered**
**Past the advertised lifetime for these tubes**
**But we run at low voltage => relatively low integrated current.**
**We anticipated on the order of 10% PMT replacement per year.**

## Drawer Repairs

**Only pulled drawers from the North Endcap**
**South has been in good shape since installation**
**Maybe two low channels that we would have liked to have examined on the teststand**
**Possibility of creating new problems when drawers are pulled => Law of Diminishing Returns sets in!**
**Total of 18 Drawers Pulled**
**Roughly equal number from NE and NW.**
**Major effort to uncable/recable an entire crate.**

## ICD Drawers

- NE Crate

- NW
- Crate

- Documentary evidence that professors occasionally do work...

## Repair Summary: NW

- NW1-CH1: Replaced PMT#9056 with PMT#7968 NW1-CH2: Replaced signal line (from socket to motherboard) NW1-CH3: Replaced signal line (from socket to motherboard) NW1-CH4: Replaced base NW3-CH3: Replaced preamp NW4-ALL: Replaced entire drawer with spare NW5-CH4: Replaced base NW5-CH5: Replaced preamp NW6-CH4: Replaced base NW7-CH5: Replaced base NW8-CH1: Replaced base NW8-CH4: Replaced preamp NW9-CH1: Replaced base and preamp NW10-CH4: Replaced base NW10-CH6: Replaced PMT#7906 with PMT#4839 NW11-CH2: Replaced PMT#5486 with PMT#8752 NW16-ALL: Replaced pulsar connector P135

## Repair Summary: NE

- NE5-CH1: Replaced base, replaced PMT#4094 with PMT#7979 NE5-CH2: Replaced base NE5-CH3: Installed spring posts (missing) NE5-CH4: Replaced base, installed spring posts (missing) NE5-CH5: Installed spring posts (missing) NE5-CH6: Relaced PMT socket, installed spring posts (missing) NE6-CH2: Replaced preamp NE6-CH3: Replaced base and preamp NE7-ALL: Replaced entire drawer with spare NE7-CH4: Replaced PMT#7487 with PMT#8019 NE11-CH2: Replaced base NE11-CH6: Replaced preamp, replaced PMT#8011 with PMT#7480 NE13-CH3: Replaced base NE14-CH4: Replaced base NE14:CH6: Replaced base NE16-CH1: Replaced base

## Radioactive Source Testing

**Andy White and Mark Sosebee also source tested 4.5 supertiles in the NE**
**Confirms mapping of an additonal 54 channels**
**Both top and bottom NE quadrants tested**
**Confirms mapping fixes to CalChan.cpp **
**In addition to sources testing previously done on other quadrants.**
**We are now confident in the ICD mapping**
**Source testing is tough**
**Signal hard to distingiush from noise**
**Need a strong source to penetrate Aluminum box**

## Conclusions

**Every ICD channels is being readout**
**Two weak channels in North and two in the South**
**A couple of other problems (pulser cable or pulser card in F/O) that do not hamper readout, but debugging a problem in the future.**
**New PMTs still need to have the High Voltages adjusted**
**Andy W. will do it this week.**
**Still need to verify teststand MIP response in situ**
**This may be a long-term goal**
**Should teststand channel-to-channel variations be used without verification with collider muons?**
**Still need to finalize ICD weighting in reconstruction.**