Public Liquid-Argon Calorimeter Plots for Collision Data

Introduction

Approved plots that can be shown by ATLAS speakers at conferences and similar events.
Please do not add figures on your own. Contact the responsible project leader in case of questions and/or suggestions.

Liquid Argon Ionization Pulse shapes

Ionization Pulse Shapes for the four elements of the LAr calorimeter: Electromagnetic barrel (EMB) Electromagnetic endcap (EMEC) Hadronic endcap (HEC) Forward (FCal) Data were collected in the special 32 sample readout mode; the prediction shown is the one used for energy reconstruction around the peak sample.

EMB eps EMEC eps HEC eps FCal eps

Timing alignment

Time difference between the side A (z>0) and side C (z<0). The average time of cells with energy above 5 sigma(noise) or 250 MeV is computed for each side and the difference is then plotted. Collision events have Delta(T) ~ 0; events with |Delta(T)| ~ 35 ns are probably beam halo or beam gas (35ns corresponds to the distance between the two endcaps). Collision data from the 23rd of November 2009 are included in this plot.	Delta(T) eps
Liquid Argon Electromagnetic Barrel (EMB): Distribution of the relative time for all of the electromagnetic barrel calorimeter FEBs. The average time among the 128 channels of each Front End Board (FEB) is computed; The average time measured for FEBs from the region |eta|<0.4 is used as a reference. The distribution shows the difference between the average time in each FEB w.r.t. to the reference time. Splash data from the 23rd of November 2009 are included in this plot.	EMB timing alignment eps
Liquid Argon Electromagnetic Endcap (EMEC): Distribution of the relative time for all of the electromagnetic endcap calorimeter FEBs. The average time among the 128 channels of each Front End Board (FEB) is computed; The average time measured for FEBs from the barrel region |eta|<0.4 is used as a reference. The distribution shows the difference between the average time in each FEB w.r.t. to the reference time. Splash data from the 23rd of November 2009 are included in this plot.	EMEC timing alignment eps
Liquid Argon Hadronic Endcap (HEC): Distribution of the relative time for all of the hadronic endap calorimeter FEBs. The average time among the 128 channels of each Front End Board (FEB) is computed; The average time measured for FEBs from the region |eta|<0.4 is used as a reference. The distribution shows the difference between the average time in each FEB w.r.t. to the reference time. Splash data from the 23rd of November 2009 are included in this plot.	HEC timing alignment eps
Liquid Argon Forward Calorimeter (FCal): Distribution of the relative time for all of the forward calorimeter FEBs. The average time among the 128 channels of each Front End Board (FEB) is computed; The average time measured for FEBs from the region |eta|<0.4 is used as a reference. The distribution shows the difference between the average time in each FEB w.r.t. to the reference time. Splash events data from the 23rd of November 2009 are included in this plot.	FCal timing alignment eps

Cell Energy Distributions

Distribution of cell energy with collision events for the four elements of the LAr calorimeter: Electromagnetic barrel (EMB) Electromagnetic endcap (EMEC) Hadronic endcap (HEC) Forward (FCal) For the data, a run with good data quality is considered. The cell energy distribution from random data (contribution of electronic noise only) is also shown, as well as non-diffractive minimum bias Monte-Carlo events. All cells, but ones known to be noisy and which are masked, are entered in the distributions. 40k events are used for the EM barrel and endcap and FCal, 5.5k events for the hadronic endcap. The distribution of cell energy in random events is not expected to be Gaussian, because the cell noise varies as a function of $\eta$(cf noise/cell vs . For the four calorimeter elements, the cell energy is measured at EM scale.

Cell Energy Distribution in EMB eps Cell Energy Distribution in EMEC eps Cell Energy Distribution in HEC eps Cell Energy Distribution in FCAL eps

Level1 CALO trigger

LVL1 CALO plots The entry in LVL1 Calo Et correlation to Offline plot is on Trigger Tower (0.1*0.1 in eta-phi range) bases, L1Et is calculated from the L1Calo ADC readout using (MaxADC-Pedestal)/4., which MaxADC is fitted by a parabola around the peak. And pedestal is calculated from recent run 136379 random events. LArgEt is the summation of energy from the cells connected to the corresponding trigger tower, convert to transverse energy. Trigger Towers with both L1Et and LArgEt greater than 3 GeV are kept. The resolution of LVL1 Calo Et with respect to LArgEt is divieded into LArgEt bin [3,5],[5,9],[9,17],[17,33],[33,65]GeV, and in each bin, the resolution fitted by a Gaussion. These plots are produced from data09_1beam physics_L1Calo.

Trigger vs standard R/O eps Trigger Transverse Energy Resolution eps

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Energy Flow in Forward Calorimeter vs Time

Run 142193 was taken on December 12th2009, during LHC beam activity. Events studied were recorded in the minimum bias stream. The ATLAS Liquid Argon Forward Calorimeter was on at nominal voltage during the entire run. No cuts on neither the energy nor the timing were applied. The red markers correspond to the total energy deposited in one of the LAr FCal sides (A) integrated over one luminosity block as a function of time. One luminosity block has a typical duration of 2min. The shaded yellow area covers the stable beam time range. The blue markers identify, within the stable beam period, known pathological luminosity blocks with short duration (forced lumi block start) or trigger inhibit. Information was extracted from random trigger rate variations. This approach is equivalent to counting events triggered by the minimum bias triggers over time, as shown in other ATLAS plots.

E vs time eps

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