Beetle Readout for the MaPMTs: First Results from the Testbeam  history of events  documentation of setup RICH meeting, Zürich, Stephan Eisenhardt University of Edinburgh   measurements & data   preliminary results

2 RICH meeting, Zürich, Stephan Eisenhardt History of Events I: pre-testbeam o Thu : first ever boardBeetle 1.2 finished and shipped to Edinburgh o Fri : lorry of carrier crashed in road accident o Mon : shipment of first boardBeetle 1.2 arrived at Edinburgh visual inspection: board OK o Wed : first data frames after sorting out problems in the I2C level adaptation and the temporary cabling o Wed : first boardBeetle 1.2MA0 finished and shipped to Edinburgh o Thu : adaptation of FED to differential read-out and first ever LED light signals via DAQ chain (boardBeetle 1.2)  success!! (although a limitation of the dynamic range was observed – amplifier saturates?!?) o Fri : test of boardBeetle 1.2MA0  success! o Sat : pack and go

3 RICH meeting, Zürich, Stephan Eisenhardt History of Events II: pre o Sun Wed : troubleshooting of interference between WinXP,NI- interface and Labview on DAQ PC o Mon : 4 more boardBeetle 1.2 delivered to CERN o Wed : move into beam area o Thu Fri : infrastructure & cabling for missing interface board o Sat : tuning of timing & first data frames with LED light and one boardBeetle 1.2 o Sun : tuning of setup for Cherenkov light & first Cherenkov photons with one boardBeetle 1.2 o Mon : cabling for the MaPMT cluster due to missing interface board o Tue : I2C problems with cluster  work around found o Wed : mounting & tuning of cluster of 8 8-dynode stage MaPMT o Thu : tuning of read-out map for right geometry match & first ring of Cherenkov photons  success!!

4 RICH meeting, Zürich, Stephan Eisenhardt History of Events III: post o Fri : 1 spare differential FED delivered to CERN to fix saturation (but of no use as with new CMS firmware) o Fri : lenses mounted on cluster o Sat : Silicon Telescope & Cherenkov counter in DAQ o Sun : TDC in DAQ & timing & DC-offset adjustment o Mon : first attempt on binary readout o Tue : data taking for: CF 4 for cluster of 8 MaPMT (Beetle 1.2) o Wed : end of testbeam… continuing with parasitic use of beam o Thu : data taking for: N 2 for cluster of 8 MaPMT (Beetle 1.2) & completion of cluster o Fri Sat : attempt to measure S-curves in binary readout data taking for: Air, CF 4 for cluster of 9 MaPMT (Beetle 1.2) o Sun : mount of cluster with 6 MaPMT (Beetle 1.2MA0) lenses, DC-offsets,…  ring fragments

5 RICH meeting, Zürich, Stephan Eisenhardt Beetle 1.2 chip: pre-bonding pads of pitch adapter pipeline front- end digital engine pads of Beetle analogue input pads of Beetle I/O

6 RICH meeting, Zürich, Stephan Eisenhardt Zoom for probe-tested Chip marks of probe needles made some problems at bonding - but finally it worked

7 RICH meeting, Zürich, Stephan Eisenhardt Pitch adapter o Pitch adapter is irregular: due to accident in submission –design was sent in low accuracy  rounding errors & shorts –layout altered at CERN to fix shorts (but not the rounding errors…) –not communication back to IC –so this structure only was found at bonding… o Cause of cross-talk??

8 RICH meeting, Zürich, Stephan Eisenhardt Equipped boardBeetle 10x8 PGAs (2 rows GND pins) Level 0: “back side” Level 5: “front side” preamp,analog, digital, comparator GND connections pitch adapterBeetle chip protective plastic cap buffer capacities and terminators 4x differential amplifiers 4x differential line drivers 4x single ended probe pins power SEQSI & I2C 4x differential out I2C address 4x pot for DC offset

9 RICH meeting, Zürich, Stephan Eisenhardt Cluster Setup base plate for mounting and grounding Cambridge bleeder board 5x boardBeetle with Beetle dynode stage MaPMT grounding points slits to access potentiometers mounting holes for lens mount mounting holes for mount to vessel HV point rotation of 4 bleeder chains

10 RICH meeting, Zürich, Stephan Eisenhardt Cluster Setup: vessel boardBeetle base plate pivot point MaPMT bleeder board photon direction

11 RICH meeting, Zürich, Stephan Eisenhardt Cluster Setup: with lenses

12 RICH meeting, Zürich, Stephan Eisenhardt Interface Board is missing… 3.3V power line for LVDS fan-out boards designed position of interface board daisy chain of power cables 5x LVDS fan out boards I2C bus 2 cable trees to distribute LVDS signals to boardBeetles

13 RICH meeting, Zürich, Stephan Eisenhardt Pre-Testbeam Results o using Heidelberg board at Edinburgh –noise –signal loss –comparison Beetle 1.2 / Beetle 1.2 MA0 o using boardBeetle at Edinburgh –first spectra –comparison Beetle 1.2 / Beetle 1.2 MA0 –Saturation –cross-talk

14 RICH meeting, Zürich, Stephan Eisenhardt Comparison using Heidelberg Board 8-dynode/Beetle1.212-dynode/BeetleMA0 less common mode noise Noise 1.3 ADC Noise 1.0 ADC

15 RICH meeting, Zürich, Stephan Eisenhardt Signal Loss Study Becki Cikoski, Edinburgh MSc Student

16 RICH meeting, Zürich, Stephan Eisenhardt First Spectra with boardBeetle before CM correction after CM correction Beetle 1.2: 800V  =1.02 Beetle 1.2: 900V  =1.06 Beetle 1.2MA0: 800V  =0.55 Beetle 1.2MA0: 900V  =0.55 Beetle 1.2: 800V  =0.77 Beetle 1.2: 900V  =0.78 Beetle 1.2MA0: 800V  =0.51 Beetle 1.2MA0: 900V  =0.53 Saturation at half the dynamic range: present before the FED!

17 RICH meeting, Zürich, Stephan Eisenhardt Saturation o A) differential amplifier –gain 10 seems too much for our signals –easy fix: gain 5 remove serial 50  ètotal gain maintained èdynamic range doubled o B) FED –Edinburgh FED was configured single-ended, unipolar –conversion to differential OK, but still unipolar (no level shifters), i.e. 0…0.75V instead of –0.75…0.75V  8-bit  7-bit reduction o … at least the two devices match…

18 RICH meeting, Zürich, Stephan Eisenhardt Cross-talk in LED Study o o Crosstalk – –two adjacent channels – –~8 % – –worst found case – –actual worst case?

19 RICH meeting, Zürich, Stephan Eisenhardt Preliminary Testbeam Results o first measurements with cluster: 8 8-dynode MaPMT & 5 Beetle1.2 –data frames, LED light, adjustment of pixel map, first Cherenkov ring o timing optimisation o noise level and CM suppression –cluster of 8-dynode MaPMT & Beetle1.2 –half cluster of 12-dynode MaPMT & Beetle1.2MA0 o cross-talk study –first approach to correct o photon yields: –Air: 960 mbar –N 2 : 960 mbar –CF 4 : 80 mbar, 800 mbar

20 RICH meeting, Zürich, Stephan Eisenhardt Data Frames sampled charge Channel ID sampled charge Channel ID cluster of 6 Beetle1.2zoom to 2 nd Beetle1.2 data frame header bits pedestals Cherenkov photons signal signature of a full ring

21 RICH meeting, Zürich, Stephan Eisenhardt LED Light o o 8 8-dynode MaPMTs – –6 new + 2 existing – –all working – –HV = 800 V o o 5 boardBeetle 1.2 – –all working o o Analysis – –in progress – –gain variation look okay

22 RICH meeting, Zürich, Stephan Eisenhardt Pixel Map

23 RICH meeting, Zürich, Stephan Eisenhardt First Cherenkov Light o o 8 MaPMTs – –no lenses – –HV = 800 V o o Cherenkov Ring – –Air 960 mbar – –3.6 pixels / event with 5 sigma cut – –from raw data

24 RICH meeting, Zürich, Stephan Eisenhardt Timing of Beam Photons o adjusted average timing between beam photons and Beetle clock –25ns jitter –measured by TDC o aim to sample at peak of signal –adjustment for average by cable delay 25ns delay: +0nsdelay: +10ns delay: +20nsdelay: +28ns sampled charge t [ns] 25ns

25 RICH meeting, Zürich, Stephan Eisenhardt Result of Timing Optimisation o made from Cherenkov Ring –Air 960 mbar –no lenses –HV = 800 V –8 8-stage MaPMTs –5 Beetle 1.2 o narrow distribution –as one expects –indicates shape of analog pulse signals at sampler in the Beetle additional delay t [ns] photons / event +18ns: final run condition

26 RICH meeting, Zürich, Stephan Eisenhardt Noise in Beetle1.2 o final noise level –after DC-offset tuning –after tuning of timing o full cluster –6 boardBeetle1.2 –9 8-stage MaPMT o from pedestal run –before CM correction è low  (1.0…1.5 ADC) èno CM problem è uniform offsets

27 RICH meeting, Zürich, Stephan Eisenhardt CM Suppression in Beam Run o from CF 4 beam run –HV= 800V –cluster of 8-stage MaPMT with Beetle1.2 o without cross-talk suppression –pedestals of ring pixels broadened background raw  =1.16 background corrected  =0.86 ring center raw  =1.56 ring center corrected  =1.18

28 RICH meeting, Zürich, Stephan Eisenhardt Noise in Beetle1.2MA0 o final noise level –after DC-offset tuning –after tuning of timing o half cluster –3 boardBeetle1.2MA0 –6 12-stage MaPMT o from pedestal run –before CM correction è lower  for charge divider (1.0 ADC) è even lower  for attenuator (0.5 ADC) è uniform offsets

29 RICH meeting, Zürich, Stephan Eisenhardt Cross-talk I: Correlation Coeff. Study by Andrew Pickford from raw datafrom CM corrected data 0.1

30 RICH meeting, Zürich, Stephan Eisenhardt Cross-talk II: tubes on one board 0.01 PMT2 v PMT2 PMT3 v PMT3 PMT2 v PMT Study by Andrew Pickford

31 RICH meeting, Zürich, Stephan Eisenhardt Cross-talk III: charge ratios o Cross-talk is: –horizontal –asymmetric ~13% right  left ~4% left  right –not vertical o Suspects: –tracks in or on boardBeetle –pitch adaptor Study by Andrew Pickford PMT2: pix1/pix2PMT2: pix2/pix1 PMT2: pix8/pix9PMT2: pix30/pix38

32 RICH meeting, Zürich, Stephan Eisenhardt Cross-talk reduction: first approach cut on one neighbour cut on four neighbours top neighbour left neighbour right neighbour bottom neighbour o LED photons: 8-stage MaPMT, Beetle1.2; with lenses, -800V

33 RICH meeting, Zürich, Stephan Eisenhardt Single Events o Cherenkov photons, CF 4 800mbar: 8-stage MaPMT, Beetle1.2; with lenses, -900V from raw data with cross-talk cut on left or right neighbour

34 RICH meeting, Zürich, Stephan Eisenhardt Cherenkov Rings I o Cherenkov photons, CF 4 800mbar: 8-stage MaPMT, Beetle1.2; with lenses, -900V from raw datawith cross-talk cut on left or right neighbour beam: -10 GeV  mostly  photons/evt6.5 photons/evt

35 RICH meeting, Zürich, Stephan Eisenhardt Cherenkov Rings II o Cherenkov photons, CF 4 80mbar: 8-stage MaPMT, Beetle1.2; with lenses, -900V from raw datawith cross-talk cut on left or right neighbour beam: -10 GeV   - and e photons/evt0.21 photons/evt

36 RICH meeting, Zürich, Stephan Eisenhardt Preliminary Photon Yield o photon yields from raw data: –no CM correction –no cross-talk correction –9 8-stage MaPMT – full ring (N 2 : only 8 tubes) –Beetle1.2 –with lenses –’99 result CM corrected

37 RICH meeting, Zürich, Stephan Eisenhardt Preliminary Photon Yield o photon yields from data with simple minded algorithm for cross-talk reduction: –no CM correction –cross-talk correction over-corrects –algorithm still questionable –9 8-stage MaPMT – full ring (N 2 : only 8 tubes) –Beetle1.2 –with lenses o further increase expected due to: –CM correction –better cross-talk correction Very Preliminary

38 RICH meeting, Zürich, Stephan Eisenhardt Unfinished Business I o cluster of 6 12-stage MaPMT & 3 boardBeetle1.2MA0: –time too short to get it to run properly –only ring fragments o measure with single base –to exclude cross-talk from bleeder board o measure with Hamamatsu bleeder board –check for load effects o test of interface board: –production only almost finished o fix saturation of amplifier o regain dynamic range in FED o fix I2C problem with cluster

39 RICH meeting, Zürich, Stephan Eisenhardt Unfinished Business II o binary readout: –in Oxford lab: threshold scan of single channel of Beetle1.2MA0 –at testbeam: threshold scan of cluster of Beetle1.2 but results not yet understood Study by Nigel Smale

40 RICH meeting, Zürich, Stephan Eisenhardt Unfinished Business III o locate source of cross-talk: –track in or on boardBeetle? –irregularities on pitch adaptor? Bond pads towards Beetle corrupted & badly fixed layout of IC pitch adaptor

41 RICH meeting, Zürich, Stephan Eisenhardt Conclusions o o the testbeam was a success: – –Beetle1.2 & 8-stage MaPMT work – –noise excellent, almost no CM – –preliminary photon yields look OK – –further analysis is ongoing o o issues: – –Beetle1.2MA0 not fully tested – –binary readout only started – –source of cross-talk – –no new data till review o o Thanks to all the people who made this result possible!!!