calorimeter status

Calorimeter Status

Pascal Perret

LPC Clermont

27 March 2012

Outline: X-mas break activities

Preparation for 2012

Ageing & Calibration

2

X-mas break activities

A lot of detector movements

Pascal Perret - LPC Clermont27/03/2012

Every thing went well and on schedule!But SPD had to be reopened to fix 1 VFE & 1 regulator board

problems …

Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr Mo Tu We Th Fr

Detector Side Activities 5 6 7 8 9 12 13 14 15 16 19 20 21 22 23 26 27 28 29 30 2 3 4 5 6 9 10 11 12 13 16 17 18 19 20 23 24 25 26 27 30 31 1 2 3

CERN Closure

AUG Cooling towers maintenance

HCAL side A M1 front, M2-M5

ECAL side A M1 front, M2-M5

PS side A M1 front, M2-M5

Lead side A M1 front, M2-M5

SPD side A M1 front, M2-M5

HCAL side C M1 back, M2-M5

ECAL side C M1 back, M2-M5

PS side C M1 back, M2-M5

Lead side C M1 back, M2-M5

SPD side C M1 back, M2-M5

HCAL side A Maintenance

ECAL side A Maintenance

PS side A

Lead side A

SPD side A

HCAL side C Maintenance

ECAL side C Maintenance

PS side C

Lead side C

SPD side C

CALO System Alignment

XCAL FEB Platform, side A,C FEEB repairs

L0 CABLES Platform, side A cable chain

PS FEB Platform, side A,C FEEB repairs

M1 side A Open

M1 side C Closed, Nacelle

M2-M5 side A Muon nacelle M2-M5 OPEN

M2-M5 side C Muon nacelle M2-M5 OPEN

Muon System Alignment

Yellow nacelle XCAL XCAL

Green nacelle M1 M1

Red nacelle

PS passerelle

XCAL Access

OPEN

A-sideC-side

Week 4 Week 5Week 3

DECEMBER JANUARY

Week 49 Week 50 Week 51 Week 52 Week 1 Week 2

# movements Distance

XCAL 30 99 m

PSPD 25 65 m

3


Beam pipe protection Installation of marks on

beam pipe protection


Installation of mechanical end stoppers when beam pipe protection is in place

ECAL

HCAL

4


Dismounting of passive dosimeter detectors for reading PS:

Mystery of a 2nd VFE resetNot yet understood …

L0 hadron trigger: cable tests (XCAL platform) Low rate errors seen in the hadron trigger, from time to time,

usually after powering on/off a crate, and solved by re-plugging the cable (in a different connector or even in the same one)

Reason not understood, very small effect on data but … Several tests done (attenuation of signal, etc.)

No evidence of problem because of weak signal levels in trigger cables

Problem with connectors ?Additional tests to do …


5


Relative crate phase measurements FEB modifications to fix the 2 regimes

observed (collisions/no collisions)The reference calibration signal given by the Sequencer of the FEB

is affected during collisions by many bit flips • ACTEL flash FPGA known problem

The solution adopted consists in taking the calibration signal before the sequencer

+ Fully equip each one of the 2 FEB with 32 channels to reduce X-talks

Cables installation between HCAL and ECAL FEB: HCAL now connected!

Survey measurements Measurements of ECAL irradiated modules


collisions (L0) - no collisions (no L0)

6


SPD Regulator boards

a slight increase in current was observed in some boards (warnings generated during operation!)• Measurements are based on a dedicated fuse• Fuse impedance increase • Exchange the fuse by a higher value avoid any future problem


6 boards affected (of a total of 16) in SM 1,2, 7, and 8 top• Boards have been dismounted and

the fuses replacedTests ok!

1 VFE showed subtractor problems for 16 channelsImpact only if consecutive eventsNew VFE board installed (same PMT)

7


SPD Maraton Backplane problems

Patch-panel measurements: 3.5V instead of 5.5V in 2 channels causing offset problems to all VFEs powered by the same RB.

Problem: loosen nuts at the Maraton backplane providing bad LV cabling contact.

Solution: access from cable platform above the gantry and use an articulated socket wrench and tighten the nuts of the connections.


8


SPD VFE

A new problem appeared once the detector were closed!• One of the voltages was wrong• Connector problems but …• This connector was stuck with

glue as emergency solution (2008) on RB side!

The damaged cable AND the regulator board had to be changed!


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> 200 nA (13)100-200 nA (14)50-100 nA (20)

rate effect > 0.2 (11)dead CW (1)


HCAL 59 PM replaced: 2x more than in 2010/2011!

Dead: 1Dark current > 50 nA: 47Unstable (rate effect>0.2)

• mainly for studies.


10


ECAL 24 PM replaced


Green: dismounted for C-W lab. studies (1)Red: the rest of replaced PMs (23)Blue: replaced connectors, PM side (9)Brown: problematic connectors, FEB side (11)Red frame: replaced LEDs (2)

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Preparations for the 2012 run

HCAL: HV tuning Reduction of PMT gain by a factor 2 to reduce radiation damage

ETmax 15 GeV 30 GeV , but higher noiseHV recipe produced are based on 137Cs run 26/01/2012


• The ratio is not exactly 0.5: it appears that PMTs’ regulation curves deviate by few % from the exact power law, G=G0∙UB.

• The final adjustment of the 30GeV recipe was done using LEDs.

12


HCAL: HV tuning Another 137Cs run done 12-Mar-2012 for check:

Cs readout system working fine at ETmax=30 GeV Quite significant gain drift since 26-Jan-2012 observed


The source speed on side C has increased by 12% (34.5 cm/s instead of stable 30.8 in 2009-2012)!• No effect, but to be understood why …

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BEFORE AFTER

HCAL: Running at ETmax=30 GeV HCAL PHYSICS HV recipe in use since March 3rd

The LED amplitudes were increased accordingly Change of trigger calibration constants needed in HCAL Front-End

boards:L0 recipe for ETmax = 30 GeV have been produced and in used Problem is that now the transition

• 01 L0ADC, is for ADC=3 (it was for ADC=6 before)• For the trigger, we compute 2x2 sums and take the highest: the board

electronics noise gives always hadron L0 candidates with non 0 ET.

ET hadron ET hadron

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HCAL: Running at ETmax=30 GeV Input and output L0 hadron candidates are sent from the Selection Boards

to the TELL1: 90 candidates.TELL1 algorithm is to suppress candidates with 0 ET, but now none of the

candidates have 0 ET, and the TELL1 must process the 90 candidates, for which it is not designed throttling when running at 1 MHz (these are the worse conditions the system can achieve)

TELL1 firmware was designed to allow suppression of candidates with ET below a given threshold: this feature is back• TELL1 configured with a Zero-Suppression threshold of 160 MeV.

In parallel, add the possibility to do this suppression directly in the Selection Board: the candidates would then be suppressed both in the DAQ and trigger paths.

The energy scale in the reconstruction (Conddb) is going to be recovered


15


ECAL: HV tuning LED change during X-mas break:


PmPin(12 Mar)/PmPin(30 Oct) PmPin(21 June)/PmPin(21 May)

AgeingRecovery Average recovery is on the level of 8÷13%, strongly depends on the detector area (up to 25% in the “horns”)

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ECAL: Ageing


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Change of HV has an impact on timing!update FEB recipeLED system time alignment to be tunedDetector timing to be checked with TAE

Required gain changeRequired gain change

/ Real gain change

ECAL: HV tuning to make uniform the gain after ageing HV have been changed for ageing over 800pb-1 to take care of

refreshing effect : π calibration used (September 25⁰ th)

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ECAL ageing & calibration

An ageing model is being built by Marie-Noelle 2 components

Neutral (neutral calorimeter clusters) • Distribution of flux weighted by cluster energy

• Corrected by cell surface


• Fit Aexp(-br) Shape of neutral flux (Tails are not described)

Charged (charged cluster flux)

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An ageing model is being built by Marie-Noelle 2 components

Charged (charged cluster flux)• Take charged cluster weighted by cluster energy• Adjust on the central zone weighted (1/ cell size)


• Parametrization A exp(-bx)exp(-cy) Radiation flux:

42% Neutral and 58% charged

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An ageing model is being built by Marie-Noelle 2 effects:

Scintillator/fiber ageing proportional to the fluxDecrease of the PMT gain due to current

• Depend of the integrated flux / cell Contribution of the 2 effects adjusted from fine calibration

• 52% PMT and 48% radiation


New coefficients are being produced for 2011 data

Deviation Sept/June Modelisation

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Calibration

Isolated electrons could also be used Selection

Only RICH was used to identify electrons;Track momentum pe > 3. GeV or pe > 10. GeV;No charged tracks within circle with R = 30 cm at ECAL entrance;Total Preshower energy deposition associated with track

• EPS > 20 MeV;

Total HCAL energy deposition associated with track• EHCAL < 1 GeV.

SampleIt was processed ~3.14x108 physical events collected by LHCb in

2011 (MagDown + MagUp BHADRON streams are used), and ~1.15x108 e-candidates were selected


O. Stenyakin, O. Yushchenko

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Calibration

Isolated electrons could also be used


The method is promising!• It can be used to

perform ECAL and PS calibration (in progress)

• More tests needed

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2012 Running

HCAL Over a ~200 pb-1 period (or at a change of the magnet polarity):

We expect a change of the gain by ~1.5%; corresponding to a ~2.5% hadron loss

Adjustment of the PMT HV according to LED system During TS

Calibration with Cs source scan ECAL

With the first collisions give new fine calibration time estimate ~ 2 weeks implemented during 1st TS

Update database + ageing Update calibration monthly


24

Summary & Conclusion

After TS 100% channels are functional ECAL & HCAL PMT HV settings have been tuned to make

uniform detector and reduce possible radiation damage effects Time alignment of the detectors have to be adjusted/checked

with TAE events an first data Piquets:

Almost the same team than last year:-3 + 1Funding could become an issue to have persons at CERN …

Calibration and ageing survey to perform all over the year Production of FmDST is a key tool for ECAL calibration Not in a routine mode! Volunteers are welcome!


25 Pascal Perret - LPC Clermont27/03/2012

26

Hadron rate understanding


-25%Muon/Hadron1.065 1.167 on-line (L0DU) -9%assuming muon rate is stable

-30%Plot from Renaud

Rate not understood ? test to be done when data taking resume

calorimeter status

Documents

ageing calibrationnxmas

place ecalhcalnxmas

regulator board problems

evidence of problem

cable platform

damaged cable

vfe resetnot

attenuation of signal