Quick VPT Test Rig meeting - minutes

Date of meeting: 8 September 2000

Venue: RAL

Present: P Flower, B Kennedy, L Lintern, D Mayer, M Sproston, J Williams

1. Mechanics
   • Almost complete.  End-stop in place for positive location of base plate.  Plate is currently held against end stop using G-clamps - need to design more permanent fixing method.  MS has ordered handles to allow easy manipulation of base plate.
2. Single-channel tests
   • MS encountered problems because the steel-reinforced drive belt is attracted to the pole tip.  Installed tensioners, and improved fixing of cog to drive shaft - these mods seem to have overcome the problems.
   • MS has carried out a -90^o - 90^o scan for RMB's NIM paper.  0^o measurement in mid-scan is significantly lower than 0^o measurements taken before and after the scan; this is not yet understood - possibly an indication of backlash in the stepper motor system ?
   • Noise is 2-3x higher than previous measurements - MS is investigating.
3. Anode current leakage box
   • ALL has almost finished wiring up the box - should be ready for testing early next week.
   • Some discussion of cathode current measurements.  Two possible methods: easier (and cheaper) option is to install 48MOhm resistors; harder option is to add 48 relays, requiring substantial extra wiring.  Will try the easy way first.
4. Readout/daq
   • ALL has ordered 8-way serial port fanout, along with 10 25-9 pin adapters and adapter cables.  Expect delivery next week.
   • JHW has made a start on the magnet control software.
5. LEDs
   • MS has received samples of the 430 and 426 LEDs, in both 3mm and 5mm sizes.  5mm versions sent to PRH at Brunel.
6. AOB
   • JHW has finished redesigning the VPT data sheet/passport as an Excel sheet.
   • ALL will try to finish wiring up the first row of 8 cans next week.
   • MS will be at CERN next week for OPAL shifts.

Bruce Kennedy / 05 December 2003