# Presentation: 543941

## Stony Brook Update

- T.K. Hemmick for the Stony Brook Crew

## Many things in these past 2 weeks

- Two dry runs of the production were done.
- Item addressed from evaporation through to the HBD vessel itself (dry runs revealed areas for improvement).
- Easiest way to discuss is to follow the path of a GEM through the system and discuss the items in that order.
- Life begins in the Evaporator...

## Quantum Efficiency

- Some suspicion of QE trouble:
- Photocathode read normal current.
- PMT read higher than normal current.
- QE low by ~20%.
- Chicklet test shows that trouble is likely a repair made to PMT system that increased its current without changing the cathodes.
- Quantum Efficiency is the normal good result when measured in Bob’s system.

## If cryos are cold, Why is it smoking?

- Cryo pump compressor makes smoke.
- After phone tag:
- That is only our brand name, we don’t service it.
- Nope, we sold it to them, they have to help you.
- Bill opened up the unit and found that the main power switch had developed a resistive character and burned.  Rest seems OK.

## Need to make QE system faster.

- After bad measurement, no fears to change circuit.
- Want QE scan to be faster.
- New wiring scheme:
- pAmmeter no longer floats at 166 V.
- Read into LabVIEW DAQ.
- PMT and cathode read at same time.

## The Low Rider...

- First Dry Run revealed that the Evaporator Box was too high when on the rails.
**Low Rider**: leading wheels go down gentle incline.
**Removable bridge**: back wheels to drop in slot.
- Low work surface.
- Locked in place.

- Removable Bridge

## Gain Box modifications.

- The lid of the Gain box is difficult to position in glove box.
- The gloves get caught in the bolts/nuts.
- Nuts now welded to the underside of top lip.
- 3 bolts are upright to act as guides to align lid accurately.
- Still heavy...what to do...hmmmm...

## Hoist System installed to ceiling.

- Two hoists ($45 each from eBay) lift the lids of the evap and gain boxes.
- Clean and new...no worries.

## More efficient data collection from GB

- Maestro (PC-based MCA software).
- Automated Gain Saturation Curves:
- One spectrum every 5 minutes.
- Root macros to plot gain curve.
- Automated Gain Map:
- Prompts user VOCALLY to move cable to next signal.
- New patch panel eliminates 50-ohm terminators.
- Complete map (56 pads) in one hour!

## Finally...the HBD is here.

- First (as requested) we cleaned it up on the outside.

## Then we mounted it to rotating fixture.

- As requested HBD is held principally by straps that run the perimeter.
- These straps are made from Industrial Velcro:
- Two mushroom-head pieces.
- No fuzzies.
- Strong, but not extreme.

## Then we put it in the glove box.

- Frame fits with HBD on it (we knew that).
- HBD can be lowered a few inches (no electronics yet).
- Rotation allows all but two end-most pieces to be installed nearly perfectly vertically.

## Issue:  Gas piping!!

- These are TWO gas inlet and TWO gas outlet connectors.
- Notice that the HV cover boxes (imagine them WITH the SHV) are in the way of a straight connection between these.
- Anyhow, do we REALLY want a SS tube running across the active area?
- NOTE:  The HBD body cannot support the weight of the 3-way valve on the inlet side!
- Idea:
- Cap one side (North, away from gas supply).
- Other side has 3-way valve on flexible bellows hanging now from rotating frame and later from support mounts.

- Two Connectors

## Issue:  Debris

- With continual use we noticed a few small flecks of debris on the gloves in the glove box.
- Dust means microscopic and often airborne.
- Debris are tiny pieces of solid.
- Searched for and FOUND source:  TOOLS!
- Removed all tools from glovebox.
- Setup (anew) Ultrasound cleaning station.
- More thorough cleaning procedure:
- Old:  Students would alcohol-wipe everything with non-dust wipe.
- New:
- 60o C-de-ionized water.
- 5 minutes each Ultrasonic frequency
- Alcohol chase (removes the water).
- Argon or nitrogen blow-dry (removes the alcohol).

## Miscellaneous

- We’re working on a wiki to keep our procedures in:
- _[http://hbd.on-wiki.net/](http://hbd.on-wiki.net/)_
- Some sections are now quite detailed.
- Some meager detail.
- Some just playing around.
- Please browse by and add pages.

## Schedules for Photo-cathode.

- Start this weekend or early next week.
- Original (leisurely schedule):
- 7 days per shot...3 shots...3 weeks.
- Reasonable schedule:
- 4 days per shot...3 shots...2 weeks.
- Outrageous schedule:
- 3 days per shot...3 shots...10 days.
- These are not particularly accurate until we begin.
- Real soon now....