1. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 1 Goal: Build a Test Stand that can test and characterize 10 PMTs. Assumptions about MINERvA Electronics:  PMT Test Stand can be supported with 704 (=11 x 64) channels of ADCs  DAQ rate 500 Hz  Integration Time = 12  s George S. Tzanakos Physics Department, University of Athens, Greece

2. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 2 MINERvA Electronics (ADCs) Multiplexer 11 PMTs Stages-Filter Wheel Trigger Unit LED pulser Stage Controller HV controller TCP/IP SCSI bus signal cables HV cables special protocol VME bus

3. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 3 Diffuser from LED Top view of multiplexer 8x8 positions The same pixel in each PMT x,y,z stages 11 PMTs per batch 64 bundles of 11 fibers

4. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 4 DARK COUNTS: 1 sec  500 windows of 12  s  0.006 s of live time 1hr  21.6 s live time, For a DC rate of 250Hz  5400 DC total Assume a 0.5 hr collection  2700 counts total  42 counts/channel OPERATING HV 5 HV settings (-750, -800, -850, -900, -950 ), 64 positions, 5000 pulses/ position, 5 sec movement time, HV Settling  64pos x (5+5HVs x(5+5000/500)) = 1.42 hr  1.5 hrs (Oxford: 5 hrs)

5. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 5 Single pe Response, Gain uniformity, Linearity, Xtalk V0. 12 filters, 64 positions, 10000 light pulses per setting  64x(5+12x(5+10000/500)) = 5.4  5.5 hrs V1. 3 HVs, 12 filters, 64 positions, 10000 light pulses per setting  64x(5+3x(5+12x(5+10000/500))) = 16.4  16.5 hrs V2. 5 HVs, 12 filters, 64 positions, 5000 light pulses per setting  64x(5+5x(5+12x(5+5000/500))) = 16.5  16.5 hrs V3. 5 HVs, 8 filters, 64 positions, 5000 light pulses per setting  64x(5+5x(5+8x(5+5000/500))) = 11.2  11 hrs (Linearity) 64x(5+10000/500) = 0.44  0.5 hrs (Xtalk). Total = 11.5 hrs V4. 3 HVs, 8 filters, 64 positions, 5000 light pulses per setting  64x(5+3x(5+8x(5+5000/500))) = 6.8  7 hrs 64x(5+10000/500) = 0.44  0.5 hrs (Xtalk). Total = 7.5 hrs (Assumed: Settling time = 5 s for each: a)x-y-z pos b) filter c) HV )

6. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 6 ConditionLinearity Gain, SPE (hrs) Xtalk (N=10000) HV Setup (hrs) DARK Counts (hrs) Total (hrs) Grand Total NposNHVNFiltN 64112100005.5Included1.50.57.517 643121000016.5Included1.50.518.528 64512500016.5Included1.50.518.528 6458500011.00.51.50.513.523 643850007.00.51.50.59.519 Assume:  4 hrs preparation of new batch and processing of previous batch  4 hrs for PMT settling  1 cycle of testing (21 hrs)  1.5 hrs to repeat HV setup and verify gain stability Additional time = 4+4+ 1.5 = 9.5 hrs  GRAND TOTAL =

7. G. Tzanakos, MINERvA Collaboration Meeting, Jan 14, 2006 7 Justification  HV: Setup HV for fixed gain  Dark Counts: verify smooth behaviour, see DC single pe pulse  Gain: Stability, pixel-to-pixel uniformity  Xtalk: Measure to use later in MC simulation of each PMT  Linearity vs HV: correct data for non-linearities