1. 1M. Ellis - Tracker PC - 7th March 2007 VLPC Cassette Characterisation  Third application (as described in past tracker meeting and CM17) is now working and has been used on the data taken from cassettes 105 and 112.  First look at cassette 105 data and compare set points determined by this application with those used at KEK.  Then look at unknown cassette 112.  Application attempts to categorise each channel as either: u Dead(no obvious light with the LED on) u Alive(good multi photon fit) u Break down(wide pedestal, no clear multi photon peaks)  The application determines for each MCM which voltage produces the maximum number of alive channels with the highest number of photons seen (i.e. maximum QE).  The gain is also returned for this optimum value.

2. 2M. Ellis - Tracker PC - 7th March 2007 Cassette 105  Was used in KEK.  Set points were taken from D0 values and then modified while at KEK to attempt to optimise the performance for the cosmic ray data taking (lower rate).  This optimisation was done “by hand”, but serves as a resonable basis for comparison.  Following plots show results of application.  Three plots per MCM: 1. Shows the number of dead (red +), alive (green *) and broken down (blue o) channels as a function of the bias. 2. Shows the gain as a function of bias 3. Shows the number of photons as a function of bias.

3. 3M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 1

4. 4M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 2

5. 5M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 3

6. 6M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 4

7. 7M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 5

8. 8M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 6

9. 9M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 7

10. 10M. Ellis - Tracker PC - 7th March 2007 Cass 105 – MCM 8

11. 11M. Ellis - Tracker PC - 7th March 2007 Cass 105 – Results AFE MCM Bias Alive Gain Num PE --------------------------------------------- 264 1 6.700000 64 7.613062 2.241665 264 2 6.700000 64 7.442847 2.681228 264 3 7.000000 64 7.310161 2.468300 264 4 6.700000 64 8.646294 2.883595 264 5 6.300000 64 7.836441 2.631982 264 6 6.800000 64 8.597677 2.667130 264 7 7.100000 64 8.774846 2.350002 264 8 6.300000 64 7.603612 2.410063 MCMKEK VCalib VGain# PE 16.86.77.62.24 26.7 7.42.68 37.17.07.32.47 46.46.78.62.88 56.26.37.82.63 66.46.88.62.67 77.07.18.82.35 86.46.37.62.41 Voltages determined by application seem to be in reasonable agreement with values used in KEK run. Gains at these voltages are also similar. Mean number of PE is uniform ~ 10% over the cassette. No dead channels in cassette 105

12. 12M. Ellis - Tracker PC - 7th March 2007 Cassette 112  New VLPCs with unknown performance.  No prior experience (D0 or MICE) so no idea of correct bias, number of dead or noisy channels, gain, QE, etc...  Application returned the following:  A few channels are apparantly dead.  Two MCMS have all channels good.  Worst MCM has 5 dead channels.  Overall: 495 out of 512 good channels. 264 1 5.500000 64 5.397580 0.429997 264 2 5.500000 61 4.732149 0.124874 264 3 6.100000 59 6.382651 1.078974 264 4 5.700000 60 5.378247 0.271078 264 5 6.000000 62 8.675414 0.903699 264 6 5.900000 62 8.554704 0.823486 264 7 5.200000 64 6.186020 1.196068 264 8 5.300000 63 6.814510 1.756557

13. 13M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 1

14. 14M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 2

15. 15M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 3

16. 16M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 4

17. 17M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 5

18. 18M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 6

19. 19M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 7

20. 20M. Ellis - Tracker PC - 7th March 2007 Cass 112 – MCM 8

21. 21M. Ellis - Tracker PC - 7th March 2007 Conclusions  When I get a chance I want to tidy up the third application so that it is a little more user friendly, then it will go into CVS.  I think the tools are working reasoanbly, although I suspect Alan and I need to spend some time together looking over the results to tweak a few things.  We can get going with the VLPC characterisation (still need to sort out cryo set points for 9.5K though).  It looks like Cassette 112 should be fine for QA work, but perhaps shouldn’t be used for a production cryostat.