calorimeter status pascal perret lpc clermont 22 march 2011

Calorimeter Status

Pascal Perret

LPC Clermont

22 March 2011

2

Xmas break activities

A lot … SPD

Resoldering of a wires on a VFE signal cable connector PS

Change of a FEE board ECAL:

Change of FEE boards, PMT, integrator boards HCAL

Change of FEE boards, PMT TELL1

Addition of 2 TELL1 for ECAL & PS/SPD Some unexpected:

HCAL incident … cf TB report on ThursdayMany thanks to the CERN teams: LHCb,

Transport, Vacuum, Survey, … Pascal Perret - LPC Clermont22/03/2011

3

Integrator boards

Pascal Perret - LPC Clermont22/03/2011

NB requires slight modification of CW bases: install 100 nF in series with 25 Ω. This does not affect the signal.

Recently, the integrators were upgraded: the 40 mezzanines were replaced with new ones.The work on production and installation of new integrator boards, including modification of host CW bases, was performed in December 2010 – January 2011 (Irina, Pavel, Anatoly Zh.).

The nominal sensitivity is 275 mV/μA (110 counts/μA). Measured at the lab before installation in 20 out of 40 boards (Pavel): ±2% deviation. When installed onto CWs, its sensitivity becomes 100 counts/μA because of the 100kΩ “safety” resistor at the CW base.

The anode current in ECAL is measured in 40 PMTs out of 6016, through “integrators”, 1-channel mezzanine boards installed at the back of each of these 40 PMT/CWs (original design by Yu. Gilitsky). Each integrator contains an amplifier for measuring current and pass-through for fast signal and LV/MV.

The readout is performed via SPECS DCU of regular CALO DAC/HV motherboards. Part of ECAL HV projects.

New version (install a 100 nF blocking capacitor in the fast signal line):• uses ~90% of the anode

current, instead of ~1%• sensitivity ~ 100 DCU

counts/μA • DC gain ~2.2 instead of

3000 no stability problems with TL072 (rad hard)

Yu. Guz

I, nA

4

Detector status

Good starting point!


SPD: Keep the 0.5 MIP recipe as the default for 2011Same threshold conditions as last year for most of the cells, only

significant changes in few outliers (0.7 MIPs in 6 cells)Can easily move to any other value if required by L0 e/ studies.

PS: 1 MIP = 10 ADC count instead of 15 ADC countValues of HV have been tuned in order to equalize all channelsTo be checked with first data

DateNumber of channels

Number of dead channels

EfficiencyMay July Sept. Nov. Feb.SPD 6016 0 0 0 1 0 1PS 6016 0 0 2 3 0 1

ECAL 6016 7 7 9 10 0 1HCAL 1448 3 3 3 3 0 1

7

5

ECAL/HCAL PM dark current

All HCAL channels are equipped with « integrator » boards: Dark current measures can be done for HCAL

To be followed (ok if < 1µA)


2011-02-06

06-Feb 12-Mar obviously increasing

2011-03-12

6

Online monitoring

Few improvements have been (or are being) implemented: Automated analyses:

Pedestal following, LED signal & gain monitoring • Reference samples out data are used to tune the thresholds that trigger

alarms in the automated analysis. They’re also used to create new alarms based on collision data.


Monitoring of the 0 mass being also added to the automated analysis:• mass histo available every ten minutes• Fit a gaussian + a polynomial (order 3)• Fill Trending histograms• Only looked at resolved 0 so far.

60min, run 80032

~1.27,

TCK 0x101710

S/B=0.19

<M>=139.40.3

=10.40.4

New plots in the DM page & new alarms on his screenOccupancy measurements: they can be used to spot dead/hot

channels, frozen FEB, etc… Data will be used to determine the thresholds that will trigger

“WARNING/ALARM/FATAL” messages on the shifters screen.

7

New LED flashing mode

Addition of an extra 11 kHz of periodic triggers for ECAL & HCAL LED flashing

This would reduce appreciably the gain variation of the PMT as function of luminosity

Commissioned thanks to Richard• Data were taken with additional

LED flashing of 11, 5.5 and 0 kHz: Rate effect up to +18% occurs.

• The rate effect at 5.5 kHz is already close to “saturation”.

• No special stability problems found in the 3.5 hour long run with 11 kHz flashing.

New LED reference samples for calibration have been built


Rate effectHCAL

8

Calibration

Different method are used consecutively in order to reach the best performances for ECAL:

Step 1: LED data to have a first calibration and to follow PMT gain changes

Step 2: smoothing of the energy flow: cell inter-calibration• Effect of trigger negligible : < 0.5% absolute effect on inter calibration• Effect of pile-up negligible : < 0.5% absolute effect on inter calibration

Step 3: Fine calibration with 0 Dead cells and border cells are removed Large amount of data needed: production of fmDST

• To be independent of the Stripping rates and to have an access to all the data collected during 2010: a dedicated production task has to be created. We're ready for production → production team

Step 4: smoothing of the energy flow to allow to recover border cells and surroundings of dead cells

We should reach an ECAL calibration at ~1.5% Pascal Perret - LPC Clermont22/03/2011

922/03/2011

Pile-up subtraction Observation on 2010 data : e/p and m(0) significantly increases

with nPV pile-up effect measured as +(0.68±0.07) MeV/c2 per PV above 1 on m(0)

was decided to subtract <EPU> per bin on SpdMult (to be independent of trigger GEC)

not trivial to define the pile-up energy <EPU> : several unsuccessful attempts …

Olivier found a working method:• for cluster at (x,y) look at 3x3 energy at the mirror position (-x,-y)• if Emirror < Ecluster /2 it is a valid ‘pile-up’ energy for that cluster

• Average Emirror per bin of SpdMult → <EPU>/bin =<Emirror>(bin i+1) - <Emirror>(bin i)

• More at: http://indico.cern.ch/getFile.py/access?contribId=27&sessionId=3&resId=0&materialId=slides&confId=130600

Pascal Perret - LPC Clermont

converted to (floating ADC)

up to ~4-5 ADC per 50 Spd inthe inner-bending plane

10

Pile-up subtraction Performance on reconstructed 0 mass

• check on fill 1427 & 1375 (October 2010 – nu > 2)


Pile-up correction implemented in software <EPU>=0.88 ADC per bin of 50 SpdMult above 200 for 3x3 areaNo longer dependency with nPV

(0 → unconverted only)

#PV <SpdMult> After Correction Before correction

μ (MeV/c2) σ (MeV/c2) μ (MeV/c2) σ (MeV/c2)

#PV=1 279 135.14 ± 0.04 7.84 ± 0.08 134.40 ± 0.09 8.6 ± 0.13

#PV=2 415 135.00 ± 0.04 8.24 ± 0.10 135.43± 0.11 8.87± 0.16

#PV=3 525 134.82 ± 0.07 8.26± 0.15 136.11± 0.17 8.96 ± 0.23

#PV=4 598 134.74± 0.12 9.26 ± 0.34 136.67± 0.33 8.19± 0.44

#PV=5 643 135.18± 0.27 9.56 ± 0.75 137.47± 1.22 6.4± 1.4

#PV=6 670 134.80± 0.74 7.63 ± 1.31

ALL PVs 134.98 ± 0.02 8.21 ± 0.06 135.35 ± 0.06 8.83 ± 0.09• Maybe slight negative gradient on mass after correction (-0.08±0.04)MeV/c2 • Note: the resolution is σ = 7.1 MeV/c2 for early data (nu << 1 , april-june) • Note : before/after correction does not correspond to same condDB (Ecorrection/Calibration)So absolute mass and sigma is not directly comparable (‘after correction’ is better tuned)

11

Reconstruction tuning for MC10

Purpose : extract reconstruction parameters from MC10 data in the same way it has been done for data :

few months needed for data, hopefully a couple of weeks for MC Tuning not yet completed

just preliminary/intermediate results shown today S-corrections and alignment :

initial MC parameters obtained from DC04/DC06 sample using MC-truth info


b parameter

OUTER MIDDLE INNER

old MC 0.102 0.129 0.144

MC10 0.133 0.158 0.169

Data 2010 0.142 0.168 0.178

S-shape main parameter :

MC10

Inner Ecal

Cluster Y

Tra

ck Y

Fit : yc = b asinh[yb/0.5 cosh(0.5/b)]+Δy

• Data parameters was 20-30% higher than (old) MC

• now: 5-7% larger than MC10

12

SPD Alignment

The SPD alignment wrt trackers has been measured for 2010 data

X coordinate: seem to be rotated around Z-axis ( / \ shape )

Rotation C-side: (0,0,-0.028º)Rotation A-side: (0,0,0.041º)

Global vertical displacement equivalent for all SM (~-7mm)

To be checked


Try to implement corrections in the condDB Rotation not foreseen …

And to re-align detectors during a long shut-down …

X coordinate

13

SPD vs M1 multiplicity

From Giovanni Passaleva, 17 January 2011:

M1 hits ~ 1/2 SPD hits


Miriam had a look: M1 hits ~ 1.1 SPD hits (October

2010 data (BHadron stream))

Same relation in MC than in data:

MC10 (bb-bar evts)

To be checked!

14

First look at 2011 data

SPD: Occupancy with first 2011 data

looks more homogeneous PS:

The MIP is consistently around 11-12 ADC counts for all boards.

Reminder: 10 ADC counts is the value of the most probable value of the Landau function.

The new calibration set in the electronics seems basically correct at that stage.

Fine analysis with tracks is required for a more detailed analysis / per channel.

Timing:Relative alignment of VFE within

σ=0.5 ns !alignment better than ±2 ns. Some ~

1 ns crate effects? Pascal Perret - LPC Clermont22/03/2011

15

First look at 2011 data

ECAL


16

Summary

Calorimeter detectors are in a good shape Few access needed during the next technical stop:

Annual control of the HCAL Cs sourceRepair of HCAL turbine C-side (control board)Fix minor problems, …

First look at 2011 data encouraging: Time alignment ok, …

Priority with first 2011 data Check gains Check spill over corrections for PS (needed with 75ns BC) Calibration Re-measure ECAL and PS, SPD (mis)alignment


17

Summary

Software: A lot of new corrections have been computed and implemented:

Energy correction, S-correction, L-correction, Alignment, …Pile-up correction implemented in software

• No longer dependency with nPVEnergy double counting in pi0 reconstruction understoodReconstruction tuning for MC10 well advanced

• good agreement with 2010 dataNew online monitoring version (to be active at pit soon)

Fine and detailed corrections took long time (and manpower) and are still not fully completed

Should be much faster with 2011 data• Hopefully we’ll just need to check the 2010 parameters are still OK for

2011• The tools to extract parameters are mostly in place


calorimeter status pascal perret lpc clermont 22 march 2011

Documents

boards pavel

new alarms

channel mezzanine boards

new ones

new version

new plots

anode current

fast signal line