06/03/06 Calice TB preparation 1

HCAL test beam monitoring- online plots & fast analysis -

- what do we want to monitor- how do we want to store & communicate information

Marius Groll

06/03/06 Calice TB preparation 2

HCAL statusHCAL Prototype:

• 1 m3

• ~8000 calorimeter tiles equipped with SiPM• 6 layers now ready• assembling of the next modules has been started• Minimum for CERN test beam: 18 layers+ ECAL+ TC

high number of channels how to control and check them? how to establish a fast feedback during data taking?

06/03/06 Calice TB preparation 3

HCAL monitoring„We would not work with dirty data (it will be meaningless)“

Vasiliy Morgunov, May 2004

What do we have to monitor?

1. Beam properties

2. Positioning of the detector

3. HCAL detector properties: dead and noisy channels

How to we communicate developments/changes?

1. Predefined checklists and logbook entries for the test beam crew

2. Database entries for the analysis team

06/03/06 Calice TB preparation 4

HCAL monitoring: softwareAll used software should be very comfortable, user friendly and stable

Software checks on recent taken data:

Three parts:

1. DAQ provided online displays on an additional DAQ-PC, which is using ROOT-Map file mean and noise averages data taking stability checksidentical information for ECAL & HCAL are already provided at this stage

BUT: some improvements are needed- real pedestal subtraction is needed- indications for the non-expert: acceptation band in histogram / reference histograms

e.g. What is a fluctuation and what is a shift in pedestal position and pedestal width?

06/03/06 Calice TB preparation 5

HCAL monitoring: software2. Data quality checks by the shift crew (Semi-online)

has to be based on event information and has to provide fast feedbackprobably different tasks for ECAL & HCAL

Task:

1. check and test the monitoring and calibration quality2. identify dead and noisy channels and label them:

- diagnostic of wrong pedestal position or its width- diagnostic of readout electronics: overflow in ADC, non-linearity of ASIC

- diagnostic of coherent noise (1 chip, 1 cable, 1 FE…)

06/03/06 Calice TB preparation 6

HCAL monitoring: software

3. Data quality checks by analysis team @ home (Near-offline / LCIO monitoring)

Task: check changes in calibration in detail- diagnostic of change in MIP peak position or its width- diagnostic of change in SiPM gain; single photon resolution- diagnostic of unusual channel spectrum (long discharge…)

06/03/06 Calice TB preparation 7

HCAL monitoring: softwareHow to do this – particular at CERN?

• Online: DAQ online histograms• Semi-Online: binaries or on-the-fly conversion

on-the-fly conversion has the advantage of reusability of the code in the final LCIO based analysis,but it is dependent on the converter status will there be a DAQ software change during this period? When the DAQ and the software will be “frozen” for the test beam?

• Near-Offline: LCIO/Marlin/LCCD based analysis on the converter output do we need a PC for this at the test beam?

• a lot of channels (HCAL alone: 4000-8000) used in different modes a lot of plots!! large screens are needed / is there a printer?

06/03/06 Calice TB preparation 8

data taking check listsHow do we take track of the observed changes:

Some predefined information has to be written in the logbook/check list for the shift crew has to be done regularly and after access

Development of user check list to monitor changes:• Give update to next shift crew• Check HV and LV• Check DAQ: errors, timeouts…• Check trigger rate; are triggers occuring at a reasonable time• Check histograms

which channels behave strange• Have recent files been written correctly to the HDD; converter job

and backup• …

06/03/06 Calice TB preparation 9

Event display

• ECAL has a beautiful event display

• we also tried something far away from the ECALstatus lets try not to duplicate it a combined event display would be the goal (switches to turn HCAL/ECAL/TC on/off)

06/03/06 Calice TB preparation 10

Beam quality and controlBeam properties effect the shower reconstruction Clean beam is needed / clean the data offline available wire chambers and cherenkov must be implemented in

DAQ readout

Goals for the offline analysis:• Beam energy resolution should be in 1 - 2% range• Good particle purity (better than 1% additional particles)• Beam spot size should be 2x2cm2 (3x3cm3) and particle position

monitoring on the 1mm level• What are the beam background conditions: halo size and gammas• Muon trigger behind calorimeter 10x10 cm2 to get clean sample?• MIP trigger in parasitic calibration mode? how?

06/03/06 Calice TB preparation 11

Conclusion

• We agree on the three monitoring stages, pointed out in the UK-ECAL task list (online, semi-online, near-offline (LCIO))

• We have a lot of different tools, but we still have to make an user-friendly monitoring/analysis program to get fast feedback like George and Götz have done it for the ECAL

this is the goal for the combined test beam at DESY in April-…

• This combined test beam rehearsal will be a major step to the running & monitoring at CERN