Section Of Calorimeter Research Articles

Study of the hadron calorimeters response for CBM and BM@N experiments at hadron beams

The results of beam tests of the hadron calorimeter with transverse and longitudinal segmentation and with the micropixel photodetectors light readout performed at CERN T9 and T10 beamlines in proton momentum range 2-10 GeV/c are shown. The new signal processing technique based on the waveform fitting of calorimeter signals using the Prony least squares method is proposed. This technique allows to identify weak signals comparable to the level of electronic noise, which is important for performing a muon calibration of calorimeter sections. For the energy calibration of the hadron calorimeter sections with cosmic muons, a new approach that uses the reconstruction of the muon track in the calorimeter is proposed.

Performance of CMS High Granularity Calorimeter prototypes in beam test experiments

The present electromagnetic and hadronic calorimeters of the CMS experiment will be upgraded to cope with the harsh radiation environment and pileup conditions posed by the high luminosity operations of the LHC (HL-LHC) expected to start in 2027. The CMS collaboration has opted for a sampling calorimeter in the endcap sections of the detector, based on silicon and scintillator technologies, with unprecedented transverse and longitudinal segmentation to facilitate particle identification, particle-flow reconstruction and pileup rejection. As part of the ongoing development and testing phase of this High Granularity Calorimeter (HGCAL), prototypes of both the silicon and scintillator based calorimeter sections have been tested in 2018 in beams at CERN. We report on the performance of the prototype detectors in terms of stability of noise and pedestals, calibration with minimum-ionizing-particles (MIPs), and energy linearity and resolution for electrons and pions. We compare the measurements with a detailed GEANT4-based simulation.

Methods of signal processing and cosmic muon calibration for the BM@N sampling lead/scintillator hadron calorimeter

Recently developed new forward lead/scintillator sampling hadron calorimeters with transverse and longitudinal segmentation will be used in the upgraded BM@N (Baryonic Matter at Nuclotron) experiment at the Nuclotron-NICA acceleration complex in JINR (Dubna). These calorimeters are very important for measurements of centrality and the reaction plane orientation in heavy-ion collisions. Digitizing the analog signals in a wide dynamic range with sampling ADC leads to the fluctuations of the measured charge. The procedure of signal processing based on the Prony least squares fit method has been developed to improve the response requiring minimum machine time. In addition, fitting the signals with a known function allows one to select effectively weak signals at the level of electronics noise, that is important for performing a calibration of calorimeter sections with cosmic muons for the BM@N experiment. The same procedure will be used for hadron calorimeter in CBM experiment at FAIR. New methods of signal processing and cosmic muon tracking for forward hadron calorimeters will be presented.

The Detector Development and Physics Program in sPHENIX Experiment at RHIC

The sPHENIX experiment at RHIC will collect high statistics proton-proton, proton-nucleus and nucleus-nucleus data, starting in the early 2020's. The sPHENIX capabilities enable state-of-the-art studies of jet modification, upsilon suppression and open heavy flavor production to probe the microscopic nature of the strongly-coupled Quark Gluon Plasma, and will allow a broad range of cold QCD studies. The sPHENIX detector will provide precision vertexing, tracking and electromagnetic and hadronic calorimetry in the central pseudorapidity region |η| < 1.1, with full azimuth coverage, at the full RHIC collision rate, delivering unprecedented data sets for hard probe tomography measurements at RHIC. In this talk, we will present a brief overview of the sPHENIX detector design with emphasis on calorimetry. The novel design of the sPHENIX calorimeters includes a tungsten/scintillating fiber electromagnetic calorimeter and two steel/scintillating tile hadronic calorimeter sections. The calorimeter has been optimized for upsilon and jet measurements in the high multiplicity environment of heavy-ion collisions. The design has been simulated in detail using GEANT4, and the simulations have extensively vetted against results obtained from the T-1044 test beam facility at FNAL. Both simulation data and test beam data, and the resulting jet physics performance, will be presented in this talk.

Time calibration of the ATLAS tile calorimeter using an integrated laser system

The ATLAS hadronic Tile Calorimeter is ready for data taking with proton-proton collisions provided by the Large Hadron Collider (LHC). The Tile Calorimeter is a sampling calorimeter with iron absorbers and scintillators as active medium. The scintillators are read out by wave length shifting fibers (WLS) and photomultipliers (PMTs). The LHC provides collisions every 25 ns, putting very stringent requirements on the synchronization of the ATLAS triggering systems and the read out of the on-detector electronics. More than 99% of the read out channels of the Tile Calorimeter have been time calibrated using laser pulses sent directly to the PMTs. Timing calibration constants can be calculated after corrections for differences in laser light paths to the different parts of the calorimeter. The calibration consists of two parts: programmable corrections implemented in the on-detector electronics, and residual deviations from perfect timing stored in a database used during the offline reconstruction of the Tile Calorimeter data. Data taken during long ATLAS cosmic runs and during LHC beam time in September 2008 has confirmed a timing uniformity of 2 ns in each of the four calorimeter sections. The remaining offsets between the four calorimeter sections, have been measured in two ways. First by using the laser pulses interleaved with cosmic triggers inside a global ATLAS run. The second method uses the real LHC events acquired during the 2008 beam time. Both methods give consistent results. The main limitations on the precision of the time calibration are presented.

The H1 lead/scintillating-fibre calorimeter

The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high-resolution lead/scintillating-fibre calorimeter. The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out-of-time background events at the first trigger level. It must be compact due to space restrictions. These requirements were fulfilled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic fibres embedded in a lead matrix. Its lead-to-fibre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter fibres with a lead-to-fibre ratio of 3.4:1. The mechanical construction of the new calorimeter and its assembly in the H1 detector are described.

Liquid ionization calorimetry with time-sampled signals

We present the results of a study of amplitude and timing measurements made in a liquid krypton electromagnetic calorimeter, using multiply sampled signals of the shaped waveform. The measurements were designed to emulate the type of data that will be available from a calorimeter operating at future hadron-hadron colliders with short (∼ 20 ns) spacing between bunch crossings. Data have been collected with 18 ns sample spacing on waveforms from individual calorimeter sections with a shaping time of 40 ns and from 5 × 5 tower analog sums with a shaping time of 50 ns. The amplitude was measured using the analog sum signal, and the timing was measured using the signal from the individual sections. The data were processed using the method of optimal filtering, and a reduction in the noise of about a factor of two over that for a single sample is seen when using multiple samples for determining the amplitude. We find an energy resolution of 6.7% E , in agreement with the resolution measured for the same calorimeter using a single sample measured at the peak of the waveform. The timing resolution for a section of a calorimeter tower with deposited energy ∈ can be expressed as ( c ∈ ) 2 + σ cal 2 , with a value of c of 0.38 GeV ns for the front section (the first 6 radiation lengths) and 0.70 GeV ns for the back section, and a value of 0.15 ns for σ cal .