Status of the RICH project CSN1 Padova 19th May 2009 Clara Matteuzzi

Status of the RICH project Highlights on what is new since the last report 1. HPD news 2. Commissioning activities C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 HPD status T.Gys, Report on HPD status LHCb 2009-016 The facts: Out of the 550 HPD tubes, 10% have experienced vacuum problems 47 HPDs in RICH-2 (20 have been replaced in the detector) 1 HPD in RICH-1 (it has been replaced in the detector) 12 HPDs in lab 22 already repaired by Photonis, tested, accepted (actually most have IFB increase rate 0.07%) C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 HPD status Remind few definitions IFB (Ion FeedBack)  ions originated by e- ionising residual gas atoms Signature of IFB  cluster size: >=5 Alice pixels glowing: When the process ion-electron emission becomes self-sustained light emission, seen by photocathode and externally Signatures of self-sustained IFB (glowing): noise (light) seen during HV ramp-up at nominal HV, even in dark count run: light cone at tube centre bias current goes into saturation during light production in HPD C.Matteuzzi, CSN1 Padova, 19 maggio 2009

IFB measurement (cw laser method) Thresholds of glowing: no glowing HPD for IFB < 5% lower threshold at IFB > 5% i.e. HPDs can turn glowing at any point between IFB=5…8% full HPD sample IFB > 5% sample number of HPD number of HPD 5% Ion Feed Back (%) Ion Feed Back (%) C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 IFB measurement IFB vs. age 90% HPD are below 1% warning threshold IFB increase per year vs. age:  90% HPD have increase<0.5%/year 0.5%/yr 1% C.Matteuzzi, CSN1 Padova, 19 maggio 2009

Lifetime extrapolation For each HPD look across IFB measurements in RICH 1&2 categorise and fit behaviour linear fit gives good prediction Predicted IFB(%) Measured IFB(%) (From Ross Young) C.Matteuzzi, CSN1 Padova, 19 maggio 2009

Predictions of IFB Development HPDs passing IFB = 5% : ~11 HPDs per year A total of 55 tubes are expected to fail in the next 5 years 12 in RICH-1 43 in RICH-2 5 RICH1 4 2 1 years 13 RICH2 9 8 7 6 Plan to replace these 20 for september years C.Matteuzzi, CSN1 Padova, 19 maggio 2009 C.Matteuzzi, CSN1 Padova, 19 maggio 2009

RICH2 – Status Map (before intervention) 27 glowing 10 not glowing IFB>5% already 9 not glowing IFB>5% in 2009 11 not glowing IFB>5% in 2010 8_181 9_101 9_120 9_115 00 8_127 8_153 9_2 9_110 01 8_121 9_10 9_59 02 8_107 9_71 8_179 03 8_112 8_60 9_114 04 8_147 8_177 05 9_127 06 9_155 9_148 8_135 9_181 07 8_133 8_124 9_189 08 9_208 09 9_137 9_12 8_122 9_265 9_69 10 8_160 9_142 8_197 9_56 9_3 11 8_110 8_134 8_154 12 8_156 9_146 13 8_157 8_178 9_15 9_125 9_250 8_176 14 8_119 9_104 8_126 8_141 15 8_130 9_123 9_11 8_108 C0 C1 C2 C3 C4 C5 C6 C7 C8 A0 A1 A2 A3 A4 A5 A6 A7 A8 57 HPDs C.Matteuzzi, CSN1 Padova, 19 maggio 2009

HPD RICH2 replacement summary (intervention march 2009) 40 removed HPDs 32 shipped to Photonis-DEP (with 1 bake-out) 7 with 2 bake-outs 1 recovered, ie with ≥1 bake-out 28 replacement tubes installed 22 repaired 1 reference tube 5 spare tubes from RICH2 spare column 12 anodes installed (no ‘active’ pd) 17 tubes “at risk” for 2009 and 2010 to be replaced with the new repaired from Photonis-DEP (if back before august) C.Matteuzzi, CSN1 Padova, 19 maggio 2009

RICH2 – HPDs status (after march intervention) 00 8_113 8_163 01 8_153 9_27 8_138 02 8_107 9_114 9_156 03 9_146 8_161 9_203 04 8_60 9_4 05 8_104 06 9_3 10_147 8_135 9_181 07 10_136 9_147 10_157 08 9_187 09 9_42 8_118 8_160 9_265 9_166 10 9_128 10_291 9_101 9_56 10_177 11 10_202 9_223 4_15 12 8_110 8_155 13 9_36 9_124 9_69 9_125 9_240 8_106 14 8_119 8_157 15 C0 C1 C2 C3 C4 C5 C6 C7 C8 A0 A1 A2 A3 A4 A5 A6 A7 A8 replace by anode use HPDs LC>3mA redeploy HPDs repaired & spare HPD C.Matteuzzi, CSN1 Padova, 19 maggio 2009

RICH2 occupancy map from MonteCarlo C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 HPD status An excellent job of systematic understanding of all the measurements done (IFB monitoring, spectroscopy measurements, measurements of other type of HPD, temperature dependence,…) has been made The conclusions are: The evolution of each tube is under control all the tubes going bad are predictable (and they do according to this prediction) The bad tubes are from the first batches produced The improvement in the quality seems correlated to the improvement in QE C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 Several studies have been performed: Glow light spectroscopy brightest spectral line seen at 486 nm (hydrogen) in all glowing tubes tested, also those with no electronics encapsulated (models PP0380AK, prototypes PP0380V 61-pixel, PP0380AK for BteV) Visible glow light emission in dark room  blue glow seen in the center of the quartz window Temperature effects  intensity of the glow light reduced after cooldown at -20 oC and stability improved at 18 kV. Glow light return after heating at 50 oC Helium permeation tests through HPD quartz window Glow effect is seen to decrease and finally to switch off when glowing tubes are annealed for several days with different protocols Photocurrent and current on grounded electrodes and anode is measured with negative voltage applied to photocathode. Seen a change in gradient which can be attributed to a threshold for gas ionization C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 HPD status Considering the new schedule of LHC, we have time (until probably september 2009) to replace the tubes which are expected to glow in RICH-2 in 2009 and 2010. This will assure a safe and stable operation of the RICH detectors for the next long period of running. Financial aspects: An agreement with DEP-Photonis has been reached and all the 100 tubes to be repaired will be shared 50% -50% between LHCb and DEP C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 First ‘real data’ C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 BEAM 1 Single event with more than 140000 recorded hits Hits are attributed to Cherenkov light in the vessel, due to beam particle slightly splashing on a collimator A strong « beam halo light » is visible on the A-side Photocathode surface is clearly defined (no electronic noise) All HPDs operational Number of hits per tube could be more than 2000 (overlaps on pixels) for fully red tubes C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 Activities in the pit C.Matteuzzi, CSN1 Padova, 19 maggio 2009

Status of the new MDMS systems Both systems have now also been surveyed. Both systems have been measured in SSB1 C.Matteuzzi, CSN1 Padova, 19 maggio 2009

Photon funnel with MDMS system The lower photon funnel was installed on February 5th and its operation checked in situ that same week. The upper photon funnel was installed on February 19th and tests were planned for february 23rd. 20 C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 RICH commissioning Responsibility has passed from T. Bellunato to T.Blake and D.Perego (similfellow INFN) C.Matteuzzi, CSN1 Padova, 19 maggio 2009

Rich commissioning and operation Tests on RICH1 and RICH2 continue: L0 calibrations New mask for noisy pixels Monitored HV ramps IFB, Calibration, etc runs MDMS …. And also : Control software upgrades going on Online monitoring improvements Update of databases C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 FEST exercise every few weeks successfully used online systems to record and monitor “data” Hitmaps, DAQ errors, trackless rings Online monitoring works well BUT…… Monitoring generally too slow 2D histograms are too big need to speed optimisation have to decide on essential monitors More will be learn and tested at the Next FEST C.Matteuzzi, CSN1 Padova, 19 maggio 2009

C.Matteuzzi, CSN1 Padova, 19 maggio 2009 Summary HPDs Expect to have a stable and efficient detector Very satisfactory progress in the study and understanding the behaviour of that fraction of HPD with vacuum problems Work in the pit and commissioning Major intervention on RICH-1 to install MDMS has been completed (plus other interventions succesfully performed) Replacement of 27 HPDs in RICH-2 performe in march09 Last repaired HPD will be installed in aug.-sept. 2009 if they are back from DEP before july General readiness RICH in good shape (FEST exercises monitoring/ data quality very useful) Use of channels for PID calibration in progress (much more at the next general RICH meeting in 1 week) C.Matteuzzi, CSN1 Padova, 19 maggio 2009

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C.Matteuzzi, CSN1 Padova, 19 maggio 2009 Upgrade activities Upgrade for data at 40 MHz foresees to change the HPD and all the front end electronics. Studies already started and going on with MaPMT kind of photodetectors. C.Matteuzzi, CSN1 Padova, 19 maggio 2009

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C.Matteuzzi, CSN1 Padova, 19 maggio 2009