1. Calorimeter Status: Preparing RUN II & LS2 Pascal Perret LPC Clermont 24 February 2015

2. 2 LS1 ACTIVITIES 24/02/2015 Pascal Perret - LPC Clermont

3. 3 Reopening of the Calorimeter …  CALO opening (January 28) Few problems to fix: PS: 1 VFE board A side (64 channels) Back before to change it ECAL: 1 PMT line (20 PMT) + 2 PMT non operational cells at the A side, because of 3 dead CW + 4 PMT C-side Pascal Perret - LPC Clermont 24/02/2015 access ECAL LEDs The 4 th problem seems to be related to the FEB and not to the PMT

4. 4 Reopening of the Calorimeter … HCAL: benefit of the access to: Fix one dead cell side A New shielding for few PMT: the idea was to try to reproduce the ECAL situation in electrostatic configuration – decouple the PMT glass from ground add insulator between the steel and the µ-metal shields remove rubber O-rings in order to study the PMT degradation problem, modify magnetic shielding in a part of PMTs (66 pc, only new ones, installed in 2014) Need to re-run the 137 C s calibration before physics data taking Pascal Perret - LPC Clermont 24/02/2015 GND O-rings (conductive) µ-metal shield contacts to ground GND conductive O-rings removed wrapped with plastic tape no contact to gnd

5. 5 Calorimeter LS1 Activities  ECAL and HCAL ECS ECAL: Both DAQ and HV are configured via the new SPECS works well, with both SpecsServer and CAT – a great success!!! Patrick and Clara continue debugging, to achieve perfection HCAL DAQ and HV work via old SPECS. the 137 C s source control and readout of integrators are migrated to linux (V. Kudryavtsev, BINP) integrated into DCS (the HCDCS project was created by Clara) fully operational (used for the source run on 06/12/2014) there is room for improvement of interface etc in case of migration to new SPECS masters, the 137 C s control may require a dedicated SPECS node (to be tested). Pascal Perret - LPC Clermont 24/02/2015

6. 6 Calorimeter LS1 Activities  CALO opening (January 28) Closed Wednesday 11/02  Last minute: Water leak on demi water circuit? ~3l lost since ~1 month … some drops identified on a manifold last week Laurent/Cédric are investigating … Pascal Perret - LPC Clermont 24/02/2015

7. 7 SPD status  VFE 24 noisy cells Two noisy cells were found in one of the replaced VFEs during cosmic data taking: Pascal Perret - LPC Clermont 24/02/2015 Solution: higher thresholds were configured. 735: 1 MIP 794: 0.7 MIPS To be checked CellIDs = 735, 794 Dec. 2014

8. 8 SPD status Check done during operation week (01/26/2015) Cosmics data taken: looks ok! Pascal Perret - LPC Clermont 24/02/2015  ECS software improvements done

9. 9 Calorimeter LS1 Activities: summary  A lot of movements/activities: ~275m Pascal Perret - LPC Clermont 24/02/2015  + Maraton maintenance, Addition of TELL1, etc. ECAL Fibre installation XCAL PMT SPD VFE CERN Open Days PS VFE Muon activities Passive dosimeters Closing/Alignment XCAL PMT Moving system maintenance Closing

10. 10 Calibration  An alternative ageing measurement has been developed by Irina and taken over by Marie-Noelle & Jean-François: it is based on raw occupancy: the method as a reminder Pascal Perret - LPC Clermont 24/02/2015 Precision reached with 1 hour data taking

11. 11 Calibration Occupancy method Compare occupancy wrt reference sample Ratio of occupancies proportional to changes in hardware characteristics Request HV changes if occupancy ratio passes some criteria Deviation > 1% & deviation > 2-sigma of its resolution This method was used in November 2012 to update ECAL HV It will remove the ageing dependence from trigger Depends on the instantaneous luminosity, trigger type, magnet polarity, etc; Need proper selection of events and of stable periods Statistics needed: goal: reach 1% error on the occupancy ratio 600K : 1% reached for half of channel (80Hz → 168 k/hour) Most channels 2000K ~ 10 hours Possible to check the agreement with LED measurement Pascal Perret - LPC Clermont 24/02/2015

12. 12 Calibration scheme 80Hz minimum bias data from ODIN/L0 Sent to a dedicated farm e.g. Calo Calibration farm as CALD007 Produce occupancy profile histogram each 10 min (50K) Store on Saveset/ CaloDAQxx with on line Timestamp From on line luminosity info select stable time interval Calculate gain change from selected stable luminosity interval Produce gain change table Produce new PMT HV settings First check of ROOT files production made successfully on FEST 2 weeks ago; new tests this week at the pit Pascal Perret - LPC Clermont 24/02/2015 Data taking Interfill period LED response could be used as a cross-check and where the statistics is too low (outer part)

13. 13 Calibration: Occupancy method  Further studies ongoing: Sample selection A sample not tagged on calorimeter could be used instead of MB: Di-muon sample is a good candidate! Pascal Perret - LPC Clermont 24/02/2015 Occupancy comparison: Factor at least 2 Up to a factor 2.8 in outer region Difference on the derived corrections MB wrt di-muon: <0.2%, RMS=2% Further checks on-going

14. 14 Calibration: Occupancy method  Further studies ongoing: magnet up/down transition Occupancy change after a polarity transition even with a small ageing Fill 2266 Magnet up - Fill 3273 Magnet down Similar effect for down/up transition Pascal Perret - LPC Clermont 24/02/2015 Idea: to build a map to derive the effect of the transition Plans: Precise determination of the ratio using all the up/down transition of 2012 Use this map on 2012 data → test method accuracy. The map can be used at the root level. More study needed to study the mu dependence

15. 15 Calibration  Occupancy method will not give the initial calibration … Fine π 0 calibration needed (with FMDST)! Alternative to off-line fine calibration under investigation Use on line cluster to calculate π 0 mass candidate / cell Uses low multiplicity event : SPD hit selected Cell without SPD hit matching to highest cell used Cell with more than 60% of photon cluster energy Request PS contribution to photon energy <10% of the cluster energy. Book 1 histo/cell Fit each histogram Determine gain to be changed using determination precision from fit quality Replace iteration by adjusted HV on the next bunch of events Data needed from 8TeV runs are estimated to be ~20 hours of data taking. Use of occupancy method to correct from ageing from fill to fill Pascal Perret - LPC Clermont 24/02/2015

16. 16 UPGRADE NEWS Pascal Perret - LPC Clermont 24/02/2015

17. 17 ASIC  2 concurrent solutions for the analog electronics The ASIC has been chosen Present version very close to the final one. The last version is being submitted and should be received in June 2015  2 test beams are planned: June 2015: most probably using the current version November 2015: final ASIC soldered on a new FEB This is an aggressive schedule for the FEB  The EDR of the ASIC should take place soon (April) However, we may wish do the EDR after the test beam Pascal Perret - LPC Clermont 24/02/2015

18. 18 New Front-End Board  CAD design of the new FEB prototype about to start Should be as close to the final version as possible Use final components 32 channels Components are defined CAD documentation received from CERN (DC-DC, GBT, …)  However, we need to decide on the number of fibres per FEB 2 solutions proposed 5 fibres: 4 for DAQ and 1 for the LLT No data reduction (full BX id transmission, 4 fibres fully independent, …) 4 fibres: LLT data embedded on the 4 DAQ fibres Data reduction necessary, more risky, but much more cost efficient ! Organize a meeting with the online experts by the end of March The firmware of the FE and Trigger PGA of the new FEB is almost written Pascal Perret - LPC Clermont 24/02/2015

19. 19 New FEB Pascal Perret - LPC Clermont GBT VTTx GBT ICECAL-ADC-FE FPGA (4ch) VTTx ICECAL-ADC-FE FPGA (4ch) GBT SCA Trigger FPGA Old FEBFirst idea on the topology on the future FEB 24/02/2015

20. 20 Next steps and milestones Choice for the Analog electronics Choice between GBT/IGLOO2 for the serialization Decide on the number of fibres per FEB by the end of March EDR/PRR milestones: EDR FE Analog → April 2015 (July ?) PRR FE Analog→ Sept. 2015 EDR FE board→ Sept. 2015 PRR FE board→ Jan. 2016 EDR Ctl board→ Jan. 2016 EDR Electronics (HV, Monitoring, Calib.)→ Jan. 2016 PRR Ctl board→ July 2016 PPR Electronics (HV, Monitoring, Calib.)→ July 2016 Ready for installation → Sept. 2018 Pascal Perret - LPC Clermont 24/02/2015

21. 21 Summary  A lot of work achieved during LS1 Detector status Detector closed: all channels are functional A small water leak has been detected on demi water system Is it on PS/SPD system? To be followed … Maraton maintenance? Calibration Good progress made First tests successful with FEST Still some work to do and new ideas on the table HCAL Cs source scan to be performed  Upgrade: Final ASIC version being submitted and should arrive in summer CAD design of the new FEB proto about to start  Ready to take data! Pascal Perret - LPC Clermont 24/02/2015

22. 22 SPARES Pascal Perret - LPC Clermont 24/02/2015

23. 23 HCAL status  HCAL PMT problem – follow-up (unstability and large dark current) Discussion with Hamamatsu on-going Few samples sent Pascal Perret - LPC Clermont 24/02/2015 From HAMAMATSU: light emission shows the place where dark current occurs Found by HAMAMATSU experts: the vacuum inside the PMT bulb is not degraded, no micro cracks in glass the problems (dark current etc) are caused by migration of alcali inside the bulb: but why??? one PMT had been baked for 1.5 hour at 125°C – the behavior improved significantly however the HAMAMATSU experts do not expect the improvement to be stable for long term

24. 24 HCAL PMT problem – follow-up Pascal Perret - LPC Clermont 24/02/2015 While the way of degradation was found (migration of alcalis within PMT bulb), the reason why it happens in ECAL and not in ECAL is unclear. We can only make hypotheses. The differences in the HCAL/ECAL operating conditions which can be relevant are only somewhat higher voltage (900 – 1300 vs 600 – 900) in combination with electrostatic conditions (grounded bulb) The limit operating voltage for this type of PMTs is 1800 V according to the specs, it is not exceeded. However an additional factor leading to the decrease of allowed voltages can be the special treatment of the dynode system, which HAMAMATSU made for us in order to decrease the rate effect When purchasing additional PMTs from HAMAMATSU, we can think of asking them to produce (a significant part of) PMTs without such treatment. The rate effect will of course become larger; however it will be mitigated by the 11 kHz LED pulsing. It can be a good compromise for (most of) HCAL, where the requirements are not very tight (5% will be good enough) – of course if the guess is right and PMTs without treatment will not experience such degradation We can also try to modify the electrostatic conditions in HCAL, by, e.g., wrapping the µ-metal shield with kapton tape In the meanwhile, we can bake the bad PMTs (we have ~150 for the moment) and see whether it will help; however HAMAMATSU experts do not expect steady improvement