# Presentation: 526483

##     - Calorimeter Calibration

** ****Overview of the calorimeter electronics**
** ****Online calibration:**
** ****Online Calibration System****	**
** ****Linearity measurements**
** ****Systematic Effects**
** ****Offline calibration:**
** ******** ****-inter calibration **
** ****Z reconstruction**
** ****E/p in W-events**
** ****Jet Energy Scale **

## Tevatron - Run II Upgrade

******p source**

**4.8**

**2.3**

**2.5**

- interactions/xing

**132**

**396**

**3500**

- bunch xing (ns)

**105**

**17.3**

**3.2**

-  Ldt (pb-1/week)

**5.2x10****32**

**8.6x10****31**

**1.6x10****30**

- typ L (cm-2s-1)

**1.96**

**140x103**

**Run 2b**

** ****Main Injector and Recycler**
** ****Increase of luminosity by reduced time between bunch crossing**
** ****Increase of beam-energy**
** ****Luminosity expected for 2002: 300 pb****-1**

##  Run II Detector

**Tracking Systems: *****solenoid, Silicon-vertex detector, Fiber-Tracker and PreShower detectors – ******provide momentum measurement***

**Calorimeter: *****Fast Read-Out Electronics, Trigger Read-Out  - ******preserve Run I performances in Run II environment***

**Shielding**

** ********-detectors: *****MDT, PDT, scintillater****** – ******increased coverage***

** **-detector, calorimeter and SI-detector fully commissioned and operational
-  Fiber Tracker/PS electronics to be completed and commissioned this spring** **

## Calorimeter – Electronics Upgrade

**55000 channels Ur/liq. Argon **
**improvements for Run II:**** **
**	****replacement  of trigger and readout electronics to accommodate  132 ns interaction time**
-  55k dual FET PreAmps
-  23k Switched Capacitor Arrays (SCA)  with 8M storage cells
-  1200 Baseline Subtraction (BLS)-boards
**~ 50 bad channels (~0.1%) **

## Calorimeter Electronics

**Calorimeter Electronics**

**Preamp/**
**Driver**

**L2 SCA**

**LAr cell**

**Calibration**

**ADC**

**Trig. sum**

**Filter/**
**Shaper**

**x1**

**x8**

**BLS**

**Analog Storage**

**BLS board**

**PreAmp Board**

**4  * L1 SCA (48 deep)**

**x8**

**gain selection**

**BLS: signal shaping, analog storage, baseline subtraction and gain selection**

**for further details see talk of Nirmalya Parua**

## Electronics Calibration

**Pulse**** controller**
**(Pulser)**

**PIB**

- Trigger

**Pr****eA****mp**
**Card**

- 6 Active Fan-outs with 16 switches:
- inductances form the pulse shape

- 6 commands (3x2)
- 96 courrents

- PreAmp
- Box

-  12 Pulsers deliver:
-  continuous current  pulse height
-  command determines pulse start

- Pulser Interface: configuration management

## Pulser & Fan-out

## Pulser commissioning

** ****measurement of current/DAC for all pulsers**
** ****<slope>= 825 mAmps/DAC**
** ****all calorimeter pulsers within 0.2%**
** ****variations of currents delivered within 1 pulser <0.1%**

**1****st**** pulser: used for ICD**** **

**slopes A/DAC**

**variation for all pulsers **

**variation each pulser **

## Pulse Shape Measurements

-  measurement of all pulse shapes in situ with final installation (Pulsers, FanOuts and PreAmp Cards)
-  study of systematic effects on signal amplitude, integral and timing
-  correction factors for differences between pulses still to be derived

## Linearity Studies

**Fit slopes**** *****a*****8**** ****and**** *****a*****1**** ****(or**** *****g = a******8******/a******1*****) for all channels**
** ****~0.25 ADC count/DAC unit **(1 DAC unit  1 MeV)
** ****g ******** 1 expected by design**

- DAC/1000

- ADC

- saturation

-  gain 8
-  gain 1

- slope = a1

- slope = a8

** ****determine calibration coefficients for channel to channel variations**
** ****verify pulser and electronics linearity **
** ****compare response as function of pulse height for gain path ********1  and ********8 **

**Response**

## Comparison of residuals from a line (ax+b) after appropriate scaling for gain 1 and 8 
below 10 ADC counts (<0.3%) above ~2 GeV
non-linearity similar for all channels
Intercept b non-zero: ~ 50 ADC counts

**below ********10 ADC counts (<0.3%) above ~2 GeV**
**non-linearity similar for all channels**
**Intercept ****b**** non-zero: ~ 50 ADC counts**

**Non-Linearity**

******10**

**DAC/1000**

** ****gain ********1**

** ****gain ********8**

**ADC**

** ****scaling residuals indicates non-linear behavior of SCA**
** ****non-scaling residuals correspond to non-linearity of pulsers**

**Residuals**

## Pulser offset

**	****Non-scaling observed for some pulsers at low DAC values**

** ****non-scaling is due to pulsers with onset of current delivered at DAC>>0**
** ****effect corrected by applying appropriate shift**

**DAC/1000**

**for example:**

## SCA non-linearity

** ****functional form of SCA non-linearity correction function**
**correction important at low energies**

**ADC to energy conversion with**
**universal function for SCA non-linearity**
**2 gains a****8**** and a****1**** ( or a****8**** and g = a****8****/a****1 ****)**
**Residuals better than ********5 ADC counts on the whole range for both gains**

## Effect of SCA-non linearity

**applied to Z********e****+****e****-**** events: peak at 89.6 GeV without any scale correction (MC 89.9 GeV)**

**for energies >200MeV non-linearity introduces an offset of ~250 MeV for the gain 8 measurements**

## Calibration Coefficients

**Dispersion:****  **
** ****~5% in em**** ****(PreAmp Type A,E,F)**** **
**~10% in had**** ****(PreAmp Type D)**** **

***a*****8****~0.25 ADC/DAC**

***g *****= a****8****/a****1****= 1+ O(1%)**

**slopes from linear fit, gain ×8:**

**ratio of slopes  gain ×8/gain ×1:**

**0.1**

**0.3**

**0.9**

**1.1**

**PreAmp Type**

**Dispersion:****  **
**~0.5% in em**** ****(PreAmp Type A,E,F)**** **
**~1% in had**** ****(PreAmp Type D)**** **

## Slope correction to Z  ee

-  = 85.1 GeV
-  = 2.7 GeV

**raw data**

**slope corrections**

**p****T1****, p****T2****>20 GeV****   **

-  = 85.0 GeV
-  = 3.0 GeV

**p****T1****, p****T2****>30 GeV**
** ****back to back**

** ****apply cell by cell calibration coefficients to em-objects**
** ****improves resolution of z-peak**
** ****doesn’t change position by constructions**

**GeV**

**Events**

**50**

**100**

##  Timing corrections

** ****all linearity runs have been taken at fixed timing, but: slope depends on timing position**
** ****but: same timing differences seen in physics and in pulser-calibration runs**
** ****only timing differences with a pulser have to be corrected**
** ****timing adjustment improved at the level of 10ns **

** ****determining calibration coefficients at the signal maximum reduces dispersion, especially for hadronic channels**

**em channel**

**had channel**

## Calibration vs. Detector Signal

**Calibration vs. Detector Signal**

** ****difference in signal shape for detector and calibration signal**
** ****calibration signal slower than detector**
** ****reflection of calibration signal **
** ****difference in response to detector parameters **

** ****detector input**
** ****calibration input**

**simulation**

** ****comparison of the variation in PreAmp input impedance (Z****in****):  ********cal/********det-1 **(phys taken as reference at its signal max)
** ****stable point at max of calibration signal (B), although correction needed  **

**time(ns)**

******cal/********det-1**

**B**

## Reflection Measurements

** ****determination of all other stable detector parameters from reflection measurements for all 55k channels**

** ****parameters extracted from fit:**

**capacitance of D-Type detector channels**

## Signal shape comparison

** ****But: signal about 20% slower from shaper output measurement in the detector comparing to simulation for both detector and calibration signals**
** ****measurement and simulation in agreement for test bench measurements **
** ****discrepancy in shape for hadronic signals**
** ****studies of these effects ongoing **

##  - intercalibration

** ****divide each ********-ring of the calorimeter in its 64 ********-modules**
** ****compare ****N(E****0****) =**** number of events with E>E****0**
**     ****S(E****0****)=**** sum of energy > E****0**
** ****determine energy**** ****E****i**** **** ****in each module ****i****, such as  the **
**	****	****N(E****i****) = N(E****ref****)****  ****with **

** ****evaluation criteria of method for data/MC - flatness:**
** ****rms of the total energy distribution in each module for 1 ********-ring**** **

## method of Z-calibration

** ****determine di-electron mass in data and MC:**

**  ****fit a Breit-Wigner to the Z-peak region of the obtained distribution **
** ****define calibration coefficients as:**

** ****w.r.t the statistics, define various detector regions in ******** for the calibration**
** ****maximize a likelihood function to determine the calibration coefficients**

## Scale Calibration with Zee

** ****calibration coefficients determined without**** ****corrections from online-calibration**
** ****calibration coefficients derived for 3 cryostat regions, which restores Z-peak at expected value**
** ****after online-corrections, calibration coefficients expected to be small**

## W e Candidates

**EM cluster**
**with SMT track**

** ****search for cluster track matching with global tracks (SMT+CFT)**
** ****E/p ~ 1 in selected W sample with E****T****>25 GeV**

**em objects**
** ****with tack match**
** ****el-id criteria**

** ****W selection**

## Jet Energy Scale 

** ****correct Jet Energy to the particle level**

** ****E****offset**** ****energy offset from underlying event, ****	****pile-up, noise**
***determined from Min. Bias Events***
** ****R****calo**** ****calorimeter response**
***using **********-jet events: Missing E******T****** Projection Fraction Method***
** ****R****cone**** ****energy contained in jet cone**
***corrections from MC - energy in cones around the jet axis ***

## JES - Calorimeter Response

** ****ideal calorimeter **

** ****jet response (with calibrated ********):**

**jet response obtained from plate level MC:**
** ****90% for E<50GeV**
** ****various parameterization models give similar response**

## Conclusions

** ****First online calibration of the new  D0-calorimeter electronics determined**
** ****no major scale corrections expected for em-objects after SCA non-linearity corrections**
** ****dispersion for em-channels ~ 5%, hadronic channels ~10% **
** ****understanding of signal shapes**
** ****offline calibration procedures established**
** ****Z-peak reconstruction**
** ****E/p matching in W-events**
** ****expected correction of JES at 10% level **
** ****quantitative results after coherent propagation of online corrections**