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

Calorimeter Status:

Preparing RUN II & LS2

Pascal Perret

LPC Clermont

24 February 2015

2

LS1 ACTIVITIES

24/02/2015 Pascal Perret - LPC Clermont

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 Clermont24/02/2015

access

ECAL LEDs

• The 4th problem seems to be related to the FEB and not to the PMT

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 137Cs calibration before physics data taking


GND

O-rings(conductive)

µ-metal shieldcontacts to ground

GND

conductive O-ringsremoved

wrapped with plastic tapeno contact to gnd

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

HCALDAQ and HV work via old SPECS. the 137Cs 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 137Cs control may

require a dedicated SPECS node (to be tested).


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 …


7

SPD status

VFE 24 noisy cells Two noisy cells were found in one of the replaced VFEs during

cosmic data taking:


Solution: higher thresholds were configured.• 735: 1 MIP• 794: 0.7 MIPS• To be checked

CellIDs = 735, 794

Dec. 2014

8

SPD status Check done during operation week (01/26/2015)

Cosmics data taken: looks ok!


ECS software improvements done

9

Calorimeter LS1 Activities: summary

A lot of movements/activities: ~275m


+ Maraton maintenance, Addition of TELL1, etc.

HCAL ECAL PS LEAD SPD HCAL ECAL PS LEAD SPD19/03/2013 5 5 4 4 6 6 5 4,5 4,5 5 O02/07/2013 1 C03/09/2013 3,8 4,8 4 4 4 C26/09/2013 3,5 3 4,5 C30/10/2013 4,5 3,5 C29/11/2013 1 0,5 0,5 0,5 C16/01/2014 4,8 O19/02/2014 4,6 O25/02/2014 4 O04/03/2014 4,8 4 4,5 C, OO19/06/2014 4,5 4,5 4,5 O25/06/2014 9 C/O22/07/2014 4,8 4 3,5 4 O29/07/2014 4,8 9,6 O,C,O04/11/2014 8 4,8 4,8 O/C, C06/11/2014 4,5 4,5 4,5 4 3,5 4 C10/11/2014 4,8 O13/11/2014 4,5 4,5 4,8 C28/01/2015 4,5 2 2 2 O02/02/2015 5 O09/02/2015 5 O11/02/2015 5 5 2 2 2 5 C

28 31,5 21 20,5 34 38,6 43,6 16,5 19,5 21,5 274,7

A C

ECAL Fibre installation

XCAL PMT

SPD VFECERN Open Days

PS VFE

Muon activities

Passive dosimeters

Closing/Alignment

XCAL PMT

Moving system maintenance

Closing

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


Precision reached with 1 hour data taking

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Calibration Occupancy method

Compare occupancy wrt reference sampleRatio of occupancies proportional to changes in hardware

characteristicsRequest 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 HVIt will remove the ageing dependence from triggerDepends 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


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 intervalProduce 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


Dat

a ta

king

Inte

rfill

per

iod

LED response could be used as a cross-check and where the statistics is too low (outer part)

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!


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

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


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

2012Use 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

Calibration

Occupancy method will not give the initial calibration … Fine π0 calibration needed (with FMDST)! Alternative to off-line fine calibration under investigation

Use on line cluster to calculate π0 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

qualityReplace 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


16

UPGRADE NEWS


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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


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 components32 channels

Components are definedCAD 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


19

New FEB

Pascal Perret - LPC Clermont

GBT

VTTx

GBT

GBT

GBT

GBT

ICECAL-ADC-FE FPGA (4ch)

VTTx

VTTx








GBTSCA

Trigger FPGA

Old FEB First idea on the topology on the future FEB

24/02/2015

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. 2015EDR FE board → Sept. 2015PRR FE board → Jan. 2016EDR Ctl board → Jan. 2016EDR Electronics (HV, Monitoring, Calib.)→ Jan. 2016PRR Ctl board → July 2016PPR Electronics (HV, Monitoring, Calib.) → July 2016

Ready for installation → Sept. 2018


21

Summary

A lot of work achieved during LS1 Detector status

Detector closed: all channels are functionalA small water leak has been detected on demi water system

• Is it on PS/SPD system? To be followed …Maraton maintenance?

CalibrationGood 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 summerCAD design of the new FEB proto about to start

Ready to take data!


22

SPARES


23

HCAL status

HCAL PMT problem – follow-up (unstability and large dark current) Discussion with Hamamatsu on-going

Few samples sent


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

HCAL PMT problem – follow-up


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 effectWhen 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 degradationWe 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

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

Documents

pmt slide

ls2 pascal perret lpc

gnd slide

pmt glass

pmt line

calorimeter hcal

calorimeter status

pmt degradation problem