Calorimetry in Particle Physics

PREFACE.

CONTENTS.

Calorimeters are widely used in astro- and particle physics experiments. They provide the means to explore new physics in an energy range from several eV to more than 10²⁰ eV. An attempt is made to discuss the historical developments of these devices. This report is far from being complete and the author apologizes for possible omissions and misquotations.

No abstract received.

Astrophysical environments produce charged particles and photons over an enormous range of energies. Single particles have been detected with energies in excess of 10²⁰eV. Studying these particles and photons requires a range of calorimetry techniques which are matched to the intensities and shower properties at various energies. At lower energies where the particle intensity is large, straight-forward techniques can be used on spacecraft or high altitude balloons. At the highest energies, the atmosphere itself is used as an interaction medium because of the huge effective collecting area required. Weakly interacting particles require low background detectors with even larger mass. Experiments are underway to use deep water volumes, the Antarctic ice, and even the Moon for neutrino detection.

Current trends in the consideration of calorimeters for a future linear e⁺e⁻ collider detector are discussed. The physics requirements and LC environment are briefly reviewed. The paradigm that excellent jet reconstruction can best be realized when the charged and neutral jet components are separated in the calorimeter is discussed. Design ideas are given, citing specific examples now under consideration in Europe, Asia, and N. America.

The Energy-Flow method is based on the idea to replace, for the charged fraction of the event, the energy and angle information as derived by the calorimeter by the much more accurate particle momentum as measured in the powerful tracker device. The optimal application of this method requires establishment of sufficient spatial and energy resolution for all individual tracks to allow efficient shower separation in the boosted jets. Thus the calorimeter has to have good energy resolution and it has to be highly granular. The imaging detector capability, along with the use of the Combined Energy-Flow technique, allows the reconstruction of almost all individual particles in an event. Reconstruction for di–jets from Z⁰ decay using the Combined Energy-Flow method within TESLA detector results in a final mass resolution of better then 3 GeV.

No abstract received.

ATIC (Advanced Thin Ionization Calorimeter) is a balloon borne experiment designed to measure the Cosmic Ray composition for elements from hydrogen to nickel and their energy spectra from 50 GeV to near 100 TeV. It consists of a Simatrix detector to determine the charge of a CR particle, a scintillator hodoscope for tracking, carbon interaction targets and a fully active BGO calorimeter. ATIC had its first flight from Mcmurdo, Antarctica from 28/12/2000 to 13/01/2001, local time, recording over 360 hours of data. The constraints, the design and the operation of this balloon borne instrument are described.

A Monte Carlo analysis, based upon FLUKA, of neutron backscatter albedoes is presented using the ATIC balloon experiment as a study case. Preparation of the FLUKA input geometry has been accomplished by means of a new semi-automatic procedure for converting GEANT3 simulations. Resultant particle fluences (neutrons, photons, and charged particles) produced by incident Carbon nuclei striking ATIC with energies up to 1 TeV/A are discussed. The analysis is part of a broad goal of simulating space radiation transport in materials science by means of the FLUKA code in conjunction with a ROOT-based interface.

A silicon-tungsten imaging calorimeter has been designed and built for the PAMELA satellite-borne experiment. The main physics task is the measurement of the flux of antiprotons, positrons and light nuclei in the cosmic radiation. The calorimeter is made by 22 layers of tungsten (each 0.74 X₀ thick) interleaved with X-Y silicon sensor planes. The signals are read out by a dedicated custom VLSI front-end chip, the CR1.4P, with a dynamic range of 7.14 pC or 1400 MIPs (Minimum Ionizing Particle) and self-trigger capability. We report on the calorimeter design details, the expected performance in PAMELA, the experimental results obtained in test beams and their comparison with simulations.

The electromagnetic imaging calorimeter made of Lead and scintillating fibers will identify the high energy leptons and γ rays in AMS-02 experiment on the International Space Station. Physics requirements and space qualification constraints lead to severe optimizations of the detector design, the mechanics and the electronics for this 16,5X₀ calorimeter sampled by 1296 electronic channels.

A full-scale prototype of the e.m. calorimeter for the AMS-02 experiment was tested at Cern in October 2001 using 100 GeV pions and electrons beams with energy ranging from 3 to 100 GeV. The detector, a lead-scintillating fibers sampling calorimeter about 17 radiation lengths deep, is read out by an array of multi-anode photomultipliers. The calorimeter’s high granularity allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. From the test beam data, linearity and energy resolution were measured as well as the effective sampling thickness. The latter was extracted from the data by fitting the longitudinal e.m. showers profiles at different energies.

GLAST is a gamma-ray observatory for celestial sources in the energy range from 20 MeV to 300 GeV. This is NASA project with launch anticipated in 2006. The principal instrument of the GLAST mission is the Large Area Telescope (LAT), consisting of an Anti Coincidence Detector (ACD), a silicon-strip detector Tracker (TKR) and a hodoscopic CsI Calorimeter (CAL). It consists of 16 identical modules arranged in a 4 × 4 array. Each module has horizontal dimensions 38 × 38cm² and active thickness 8.5 radiation length. It contains 96 CsI (Tl) crystals arranged in 8 layers with 12 crystals per layer. The scintillation light is measured by PIN photodiodes mounted on both ends of each crystal. The sum of signals at the two ends of the crystal provides the energy measurement. The difference in these signals provides the position measurement along the crystal. The calorimeter was designed to meet the goals of good energy resolution (better than 10% for photon energies 100 MeV - 100 GeV), position resolution of ~ 1mm for photon energies > 1GeV, and a rejection factor of > 100 for charged cosmic rays, under limitations on calorimeter weight (95 kg per module) and power consumption (6 W per module). The Monte Carlo simulation and prototype beam test results confirm that proposed design meets the requirements. Calorimeter production is planned to start in 2003.

The GLAST Large Area Telescope to be launched in 2006 is dedicated to gamma-ray astronomy from 20 MeV to 300 GeV. Its calorimeter consists of 16 modules of 8 layers of 12 CsI(Tl) crystals arranged in an hodoscopic array. Each module is placed under a silicon tracker using tungsten converters. The calorimeter is only 8.5X₀ thick. Therefore, depending on the energy regime, the shower containment is rather poor and corrections need to be applied. We present here the correction algorithms as well as the performances of GLAST calorimeter in terms of energy, position and direction, based on detailed simulations of the instrument and beam tests results.

CREAM is slated to fly as the first NASA Ultra Long Duration Balloon (ULDB) payload in late 2003. On this 60-plus-day flight CREAM is expected to collect more direct high-energy cosmic ray events than the current world total. With three such flights CREAM is expected to have a proton energy reach above 5×10¹⁴ eV, probing near 100 TeV for the predicted kink in the cosmic-ray proton spectrum. With a Transition Radiation Detector (TRD) above a sampling tungsten/scintillator calorimeter, an in-flight cross-calibration of the absolute energy scale becomes possible with heavy ions. We report on results from a 2001 beam test of the calorimeter in an SPS beam at the European High Energy Physics lab (CERN) and on the planned in-flight calibration.

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is a wide energy range (50 GeV - 50 TeV) imaging atmospheric Cherenkov detector that will provide a high sensitivity and good energy resolution for astrophysical γ-ray sources. Recent discoveries of γ-ray blazars have opened the possibility of probing the intergalactic IR fields by analyzing the shape of TeV γ-ray spectra. Also, the search for the origin of cosmic rays using secondary γ-rays requires accurate energy spectral measurements. The technical concept and design of VERITAS and its capabilities for calorimetric measurements are discussed.

The Pierre Auger Observatory is designed to observe and study a high statistics sample of ultra high energy cosmic rays (UHECR) with energy greater than 10¹⁹ eV. The hybrid nature of the observatories, using both air-fluorescence and ground water Cherenkov array, will enable Auger to measure the energy of the cosmic ray showers with an improved accuracy compared to previous experiments. With a surface area of ~ 3000 Km², and an effective aperture of at least 7350 Km²Sr for each observatory, the PAO will be the world’s largest calorimeter to date, and will be able to conclusively determine whether the cosmic ray spectrum extends beyond the GZK cutoff. The Auger detector components, and the status of the observatory are described in this report.

The Extreme Forward Calorimeter (EFC) at Belle has been operating since the spring of 1999 on KEKB. It consists of 320 radiation-hard BGO crystals surrounding the beam pipe to cover the small angle region in both forward and backward directions. The main function of EFC is to provide on-line luminosity information using Bhabha scattering and it also acts as a tag for two-photon production events. The calorimeter has been performing well and running stably under high luminosity and beam currents. Its performance and status are presented.

The BABAR detector at the B-factory at SLAC is equipped with a calorimeter consisting of 6580 CsI(Tl) crystals. This allows for the measurement of the energies of photons and neutral pions and the identification of electrons with high precision, needed in the reconstruction of B-meson decays. The detailed performance of the calorimeter will be presented. As the B-factory operates at high luminosity the calorimeter is exposed to substantial background and radiation damage. The calorimeter is calibrated regularly at different energies in order to meet the precision goals. The calibration methods include the use of a radioactive source, Bhabha events, radiative Bhabha events, π⁰-Mesons, and a light pulser system. This article largely follows reference¹.

We study the impact of radiation damage on large CsI(Tl) crystals in the BABAR electromagnetic calorimeter. Average radiation exposure of up to 400 Rad to date, originating primarily from beam backgrounds, has been measured by RadFETs located at the front face of crystals.

The electromagnetic calorimeter of the BELLE detector built for experiments on B-meson physics is described. The calorimeter consisting of 8736 CsI(Tl) crystals demonstrates its good performance in the experiment while its parameters are close to the project ones. The luminosity monitoring and tolerance to high background conditions are briefly described as well.

In this paper we present results of the development of yttrium doped lead tungstate crystal at Shanghai Institute of Ceramics. The crystal growth by modified Bridgman method is described. The segregation coefficient of yttrium ions in lead tungstate crystals was determined. The scintillation emission and transmittance spectra, light output, decay kinetics, light response uniformity and radiation induced color centers were measured. It is found that yttrium doping suppresses the slow scintillation component and improve crystal’s radiation resistance.

The PrimEx collaboration at Jefferson Lab is planning to perform a precision measurement of the neutral pion lifetime via the Primakoff effect. This will be a state-of-the-art experimental determination of the lifetime with a precision of less than 1.5%. Such a measurement requires an electromagnetic calorimeter with high resolution and high efficiency for detecting the photons from pion decay. A new electromagnetic hybrid calorimeter is under construction at Jefferson Lab consisting of 1200 lead tungstate (PbWO₄) crystal detectors and 600 lead glass Cerenkov modules. Recent beam tests were performed with few GeV electrons on the PbWO₄ crystals obtained from two different manufacturers (Bogoroditsk, Russia and Shanghai, China). Results from energy and position resolution studies, and the dependence of detector response on radiation rate are presented.

A compact photon detector with nearly 4π-coverage in solid angle has been proposed to be implemented into the magnetic spectrometer ANKE at COSY, Jülich. Based on the physics program and the experimental requirements the instrumental concept will be presented. As part of the R&D program, the response functions of PbWO₄ to photons and charged particles have been measured at different accelerator facilities up to energies of a few GeV and are compared to fast scintillator materials such as CeF₃ and BaF₂. The applicability of fine-mesh photomultiplier tubes (Hamamatsu R5505) has been tested successfully for the read-out of first prototype detectors.

The CMS experiment at the LHC has decided to install a homogeneous electromagnetic calorimeter made of about 80000 PWO scintillating crystals. The LHC is a very hard environment for both the radiation levels in the detectors and the high beam crossing rate, so very demanding requirements are set on the characteristics of the detector. After a long R&D the PWO crystals are now well adapted to the experiment. We will review the crystal properties and their implications on the calorimeter performance. In particular we will discuss the light collection crystal uniformity and its effect on the constant term of the calorimeter resolution, measured in a high energy electron beam.

Avalanche Photodidoes (APD’s) will be used to readout the CMS barrel electromagnetic calorimeter. After several years of detailed prototyping studies the final design of the CMS APD is now fixed and it is now in production. The design of the calorimeter will make access to the APD’s extremely difficult once they are installed. In view of this the APD group has devised a system of tests to ensure that the APD’s will have a high-probability of surviving for ten years in the harsh environment in the CMS detector. In this paper we describe the methods that we have adopted to select the APD’s for the CMS detector.

The CMS electromagnetic calorimeter is now in its construction phase. The barrel part of this calorimeter consists of 36 super-modules containing in total 61200 PbWO4 crystals equipped with 2 avalanche photodiodes (APDs). Each super-module contains 1700 crystals assembled in 4 modules. The construction of these modules is shared between two regional centres, CERN and INFN/ENEA Rome. Prior to the construction, all the ECAL components follow a strict quality control procedure. In this paper, a presentation of the organisation of the ECAL barrel construction, a status of the construction progress as well as the results of the quality control of some components like crystals and APDs will be given.

No abstract received.

The instrumentation used for the nuclear medical imaging technique of Positron Emission Tomography (PET) shares many features with the instrumentation used for electromagnetic calorimetry. Both fields can certainly benefit from technical advances in many common areas, and this paper discusses both the commonalties and the differences between the instrumentation needs for the two fields. The overall aim is to identify where synergistic development opportunities exist. While such opportunities exist in inorganic scintillators, photodetectors, amplification and readout electronics, and high-speed computing, it is important to recognize that while the requirements of the two fields are similar, they are not identical, and so it is unlikely that advances specific to one field can be transferred without modification to the other.

Systematic R&D on basic mechanism in inorganic scintillators, initiated by the Crystal Clear Collaboration at CERN 10 years ago, has contributed not to a small amount, to the development of new materials for a new generation of medical imaging devices with increased resolution and sensitivity. The first important requirement for a scintillator to be used in medical imaging devices is the stopping power for the given energy range of X and γ rays to be considered, and more precisely the conversion efficiency. A high light yield is also mandatory to improve the energy resolution, which is essentially limited by the photostatistics and the electronic noise at these energies. A short scintillation decay time allows to reduce the dead time and therefore to increase the limiting counting rate. When all these requirements are fulfilled the sensitivity and image contrast are increased for a given patient dose, or the dose can be reduced. Examples of new materials under development by the Crystal Clear Collaboration will be given with an emphasis on the major breakthrough they can bring in medical imaging, as compared to present equipments.

GePEToS is a simulation framework which we have developed over the last few years for assessing the instrumental performance of PET scanners under development. It is based on Geant4, written in OO C++ and runs on Linux platforms. The validity of GePEToS was tested on the well-known Siemens ECAT EXACT HR+ camera. We also present the results of two application examples: the configuration optimization of a liquid Xe μPET camera dedicated to small animal imaging; the evaluation of the effect of a strong axial magnetic field on the image resolution of a Concorde P4 μPET camera.

Electromagnetic calorimeters based on silicon sensors are under consideration for detectors at future linear colliders. This session reviews some existing special purpose devices as well as plans for calorimeters at linear colliders.

A pair of compact Silicon-Tungsten calorimeters was operated in the OPAL experiment at LEP to measure the integrated luminosity from detection of Bhabha e^± scattered at small angles from the beam line. The performance of the detector at both LEP-I and LEP-II is reviewed.

The hadron electron separator (HES), a component of the ZEUS experiment is designed to improve the identification of electrons generally and, in particular, within jets. It consists of 20518 silicon diodes with 20m² active area. The diodes are installed after 3–5 X₀ of the electromagnetic uranium-calorimeter, where the maximum intensity of the shower is expected. With an analog readout of each channel the deposited energy is measured. The HES improves the electron identification by a energy dependent factor 2.5 to 5 and the granularity by a factor 10. The attained position resolution is 5.4mm.

We discuss some issues relevant for a highly granular silicon-tungsten electromagnetic calorimeter, such as those currently being designed for a future linear collider detector. An important issue is the interplay between the silicon pixels and readout electronics. Here, we propose an integrated solution.

In the framework of the ECFA- DESY study for an electron linear collider we have studied a calorimetry intended to be well suited for jet measurement. As a result we contend that the best solution for the electromagnetic part is a silicon- tungsten sandwich. We describe here the current status of the study going on inside the CALICE collaboration: http://polywww.in2p3.fr/tesla/calice.html.

After a short reminder on the physics to be expected at the linear collider, we state what may be the requirements for the electromagnetic calorimetry and a possible “optimum” design. As an example of implementation the ECFA- DESY TDR design is briefly sketched. We then focus on the current R&D developments for electromagnetic calorimetry in the CALICE collaboration and its objectives, the current design of prototypes and the perspectives.

No abstract received.

We have simulated and reconstructed one million of QCD jet events. This study was done with CMS full detector simulation, based on GEANT3 package, and object-oriented CMS C++ reconstruction program. The understanding of QCD jet background is important for the Higgs search in two-photon decay mode. The comparison with other types of backgrounds was also done. It was shown that the isolation tools were important ones to isolate the signal process from the huge background one. Using the isolation criteria based on the information from PbWO₄ electromagnetic calorimeter and the tracker we were able to reduce the QCD jet background to 15% of the total one.

Signals from electrons and muons taken at testbeams with different modules of the ATLAS Liquid Argon Calorimeter have been compared to corresponding simulations using the GEANT4 toolkit. These simulations have also been compared in some detail with GEANT3 based predictions. Results for signal linearity, energy resolution, and shower shapes all generally indicate a good agreement between experiment and the two simulation packages, typically at the level of a few percent.

The electromagnetic calorimeter of CMS consists of a barrel and two endcap calorimeters containing a sum of over 80000 lead tungstate crystals. If all the crystals were to be read-out in a triggered event, the total amount of ECAL data would excess by a factor 20 the CMS data acquisition system limits allowed for ECAL. This paper presents the strategies developed by CMS in order to reduce the ECAL data volume to the required level.

The upgraded CDF II detector has collected first data during the initial operation of the Tevatron accelerator in Run II. The simulation of the CDF electromagnetic and hadronic central and upgraded plug (forward) calorimeter is based on the Gflash calorimeter parameterization package used within the GEANT based detector simulation of the Run II CDF detector. We present the results of tuning the central and plug calorimeter response to testbeam data.

Results of Geant4 based simulations of the response of the ATLAS hadronic endcap calorimeter to charged pions are presented. The first results of hadronic simulations with Geant4 for the ATLAS forward calorimeter are shown as well. Predictions of Geant4 and Geant3 on energy response and resolution for charged pions are compared. Where it is possible, the comparison with experimental results of beam tests is done.

Several MC Studies of the Tile Hadronic calorimeter (Tilecal) using GEANT3 and GEANT4 have been done after tunning the code with data from tests with high energy particle beams at CERN. The comparision between the two codes started with the study of the simulation of the electromagnetic interactions and results are presented. A preliminary study of the evaluation of the simulation of the hadronic interactions is also presented.

The measurement of jets and missing transverse energy reconstruction will play an important role for many physics channels at the Large Hadron Collider (LHC). The performance of the ATLAS detector for reconstructing jets and missing transverse energy has been evaluated using detailed simulations. In this paper results based on these simulations will be shown for the jet energy resolution, in addition to some selected examples of the simulated jet and missing transverse energy physics performance. Special emphasis will be put on the experimental aspects like electronic and pile-up noise, non-compensation, and dead material, as well as their realisation in the simulation.

The CMS calorimeter is a non-compensating calorimeter and has non-linear response to jet energy. A 4 Tesla magnetic field in a tracking volume induces extra smearing of energy measurement by the calorimeter. Various algorithm to improve the measurement have been tested. A simple mapping of the calorimeter response to jets is implemented in the trigger and more sophisticated energy flow algorithm may be used at a later stage.

No abstract received.

The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAΦNE, the Frascati ϕ-factory. A lead scintillating-fiber sampling calorimeter has been built, providing good energy resolution and timing accuracy. The calorimeter is calibrated on-line using cosmic rays, Bhabha, and e⁺e⁻ → γγ events. ϕ decays are then used to monitor the performance.

We report monitoring and calibration issues to have stable operation of the Belle electromagnetic calorimeter. As a result, good mass resolutions for π⁰ and η are obtained to be 4.8 and 12.1 MeV/c², respectively. The degradation of light output due to the radiation damage is small, about 3% for the radiation dose of 40rad.

One of the main components of the ZEUS detector at the HERA storage ring is the Uranium Calorimeter (UCAL). It has been running successfully since ZEUS started data taking in 1992. The UCAL is a Uranium-Scintillator calorimeter with equal response for electrons and hadrons , a linear energy response and a high energy resolution of for electrons and for hadrons. It covers 99.7% of the solid angle and is able to handle bunch crossing rate of up to 10.4 MHz. This performance demands a very precise calibration and a constant monitoring of the detector. In this paper we present the procedure to achieve a calibration accuracy of better than 3% and to maintain it stable to better than 2% for more than 10 years.

In the early summer of 2000, the PHENIX experiment for heavy-ion physics at RHIC began, and that for spin physics was started in 2001. In this experiment, the electromagnetic calorimeter (EMCal) plays an important role in detecting photons and electrons/positrons. In order to cover topics in both areas of physics, e.g., thermal photon measurements in heavy-ion physics, and prompt photon, π⁰ and weak boson measurements in spin physics, the EMCal must cover a wide energy range from a few hundred MeV to 80 GeV. Spin physics also requires the energy measurement to be within 2% accuracy for measuring cross sections of prompt photons and π⁰ production with 10% errors, because the cross sections have steep transverse momentum (p_T) slopes. The PHENIX EMCal consists of a lead scintillator (PbSc) and lead glass (PbGl). In this paper, we will report the performance of the PbSc and the achievement of 2% accuracy.

The front-end electronics of the DØ Ur/liquid Argon Calorimeter has been replaced for the Run 2 of the Tevatron to operate with the new shorter time separation between particle bunches (396/132 ns compared to 3.5 μs for Run 1). The signal shaping was changed to accommodate this shorter time between bunches. That change led to the replacement of the existing electronics calibration system so that the injected calibration pulse shape would more closely match the actual detector pulse shape. First results using the online calibration system as well as the off-line calibration from reconstructed object are presented.

Three different methods of setting the hadronic energy scale of a longitudinally segmented calorimeter system are compared with each other. The merits of these methods have been studied with testbeam data from the CDF Plug Upgrade Calorimeter. It turns out that one of the calibration methods introduces a number of undesirable side effects, such as an increased hadronic signal nonlinearity and a dependence of the reconstructed energy of hadrons on the starting point of their showers. These problems can be avoided when a different calibration method is used.

The MINOS experiment employs both a far and near detector to study neutrino oscillations. The near detector is used to characterize the beam before it has travelled far enough for oscillations to significantly occur. Oscillation measurements, including the energy spectrum of charged-current events at the near and far detectors, are made by comparing the events observed at the far detector to those in the near detector. The relative calibration of the near detector and the far detector, and the different regions of the far detector itself, is paramount in the interpretation of the oscillation results. The absolute calibration is established using a small Calibration Detector while the relative calibration is established using cosmic-ray muons and a light injection system to track short term variations in detector response. In this paper we present the overall strategy for calibration of the MINOS detectors and first results in calibration using muons and light injection in the calibration detector.

The MINOS Calibration Detector (CalDet) is a small version of the MINOS Near and Far neutrino detectors. A program of exposure to beams of muons, electrons, pions and protons at the CERN PS will provide calibration of the calorimetric and topological response of the Near and Far detectors. In this talk, we briefly discuss the goals and design of the CalDet and present first results from the initial beam exposure.

The Sudbury Neutrino Observatory (SNO) is a heavy water (D₂O) Čerenkov detector designed to detect ⁸B solar neutrinos. This is done via the charged-current, neutral-current, and neutrino-electron elastic scattering interactions with the target D₂O. Success of the experiment necessitates an extensive calibration program for characterizing and testing the SNO detector’s response to Čerenkov light producing particles as well as backgrounds. This has required the development of a variety of specialized calibration devices which includes sources of isotropic light, γ-rays, neutrons, and β-particles. A detailed description of these devices along with the results of their application in the SNO experiment is given.

The AMANDA-II neutrino telescope currently operating at the South Pole is an array of 677 optical modules (OMs) deployed in the ice at depths between 1200 m and 2300 m beneath the surface. Calibration of the timing offsets of each OM is effected primarily by means of in-ice light pulses transmitted via optical fibers from a surface YAG laser. Discriminator walk, which is significant due to the transmission of electrical signals over 2 km distances, is also calibrated using the YAG laser. Another way to calibrate the timing offsets is to use downgoing cosmic ray muons. This method has the advantages of fuller coverage and year-round availability, i.e., it can be done anytime the detector is taking data. Finally, preliminary results of a technique used to calibrate, with nanosecond precision, the local clocks in “digital optical modules” (DOMs), which digitize and timestamp PMT signals in situ, are presented using DOMs in operation in AMANDA-II. The DOM is part of the baseline design for the planned IceCube detector.

Physics processes Z⁰ → e⁺e⁻, W → e^±ν_e, J/ψ → e⁺e⁻ and ϒ(1s) → e⁺e⁻ were investigated for calibration of the electromagnetic calorimeter in site at LHC. The production cross sections of these processes, including high order corrections, were calculated by using PYTHIA 6.136 as well as CDF data. As an example, the Level 1 trigger efficiency was calculated by using events simulated with CMSIM 121 and ORCA_4_4_0_optimized. The result of this investigation indicates that although the process of J/ψ → e⁺e⁻ has a factor of 16,000 larger cross section as compared to that of Z⁰ → e⁺e⁻, about 1 or 0.5 year data taking at relatively low luminosity of 10³²cm⁻²s⁻¹ or 10³³cm⁻²s⁻¹ respectively is still required to reach a sub percent calibration precision by using electron pairs from J/ψ. A combination of all physics processes thus may be needed at the beginning of the data taking.

Light monitoring will track variations of the calibration of the CMS lead tungstate crystals in situ at LHC, which is crucial for maintaining crystal calorimeter’s sub percent constant term in the energy resolution. This paper presents the design of the CMS ECAL monitoring light source and high level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of yttrium doped PbWO₄ crystals were investigated, and were used to study monitoring linearity and sensitivity as a function of wavelength. The monitoring wavelength was determined so that a good linearity as well as adequate sensitivity can be achieved. The performance of a custom manufactured tunable laser system is presented. Issues related to monitoring precision are discussed.

A multichannel Light Monitoring System (LMS) based on super-bright blue LED, has been developed for the high resolution electromagnetic hybrid calorimeter (HYCAL) at Jefferson Lab. The central part of the calorimeter consists of 1200 PbWO₄ crystal modules. The prototype LMS has been constructed and tested, and has demonstrated a capability of providing an adequate light pulse per each channel, equivalent to the signal of 5 GeV electrons in the detector. The final Light Monitoring System with 1800 output channels and fiber optics light distribution system is presently under construction. The light source of the LMS represents an assembly of 31 super bright blue LEDs connected in series. The uniformity of the output light is achieved by mixing light from the LED assembly in an integrating sphere. The light intensity is being monitored using PIN photo diode and reference photomultipliers with Am²⁴¹ radioactive source. In order to achieve (0.1 - 0.3)% long term stability, the system including the light source, the photo diode with the preamplifier and the reference PMT, is thermally stabilized.

No abstract received.

Cubic lead fluoride (PbF₂) crystals were grown by non-vacuum modified Bridgman method. Their optical transmission may deteriorate because of oxygen contamination during growth, annealing and machining, storing and carrying. It was found that the role of oxygen is to promote the transformation of β → α phase in the initial cubic structured mono-crystals, which results in the formation of cryptocrystalline or microlithic texture composed of crystalline α-PbF₂ grains. This texture is suggested to be responsible for the transmission loss of lead fluoride crystals.

We describe the design and construction of a gas Cerenkov Calorimeter with three unique features: 1) it is constructed wholly of metal and gas and therefore indestructible by any dose of radiation; 2) the Cerenkov threshold is above 10 MeV so it is completely blind to any radioactivation as well as low energy e^±γ; 3) it has a time resolution of about 50 ps. The response is directionally sensitive and can be exploited, for example, in muon colliders - suppression off-axis muon and decay e halo backgrounds. The manufacturing is robust and inexpensive, making this calorimeter suitable as a luminosity monitor for existing hadron colliders and possibly as the only surviving technology for future colliders at high energies and luminosities above 10³⁵cm⁻²s⁻¹.

The experiments at the Large Hadron Collider will have to deal with unprecedented radiation levels. The design of the CMS forward calorimetry detector (HF) is now finalized. The present design of CMS calls for the HF calorimeter to be based on quartz fiber technology. It consists of two modules, located symmetrically at about 11 meters from either side of interaction point. They cover the pseudorapidity range 3-5. The length along the beam is 1.65m or 10 nuclear interaction lenghts. Each calorimeter consists of a large steel block that serves as the absorber. Embedded quartz fibers in the steel absorber run parallel to the beam and constitute the active component of the detector. In order to optimize energy resolution for E and E^T flows and forward jets, the calorimeter is effectively segmented longitudinally by using two different fiber lengths. The present status will be discussed.

Radio Ice Cherenkov Experiment (RICE) is an ultrahigh-energy (UHE) cosmic ray neutrino detector for neutrino energies greater than a PeV. This pilot project explores the radio detection technique for UHE particles. Deployed at the Antarctic polar ice cap, RICE antennas have been operational since 1996. Basic calibrations of the antenna array have been done using data taken mostly in situ. The calibration results and an upper limit on electron neutrino flux based on one month of analyzed data are reported here.

Darkening of various types of high OH⁻ fibres were studied by irradiating them with 500 MeV electrons. The transmission of Xe light was measured in situ in the 300-700 nm range. The induced attenuation at 450 nm is typically (1.52 ± 0.15) dB/m for 100 Mrad absorbed dose. Two-parameter fits for darkening were presented. After irradiation the tensile strength remains essentially unchanged. For Polymicro quartz core fibres the tensile strength is typically (4.6 ± 0.4) GPa.

No abstract received.

The status of the construction of the ATLAS TILECAL hadron calorimeter is reported. The various aspects of the construction started at the end of 1998: mechanics, optics, instrumentation, certification and final integration will be presented. At present 80% of the 3 cylinders: 1 barrel and 2 extended barrels is fully instrumented and stored at CERN. Various quality control steps are done during the components production and during the modules instrumentation. An evaluation of the modules uniformity extracted during the final certification using a radioactive ¹³⁷Cs source is shown. The status of the electronics production and the modules performance extracted during the calibration with particle beams are described in other talks of this conference presented by M.Varanda, F.Martin and S. Nemecek.

Extensive studies of the ATLAS Tile hadron calorimeter, TileCal, performance were conducted between 1996 and 1998 on full size prototypes. The construction of the calorimeter started in late 1998. Research activities since then focussed on controlling the energy resolution and sensitivity to muons. Most of the activities take place at the SPS H8 beam line at CERN. The status of these studies is presented, with comparisons to results on prototypes. An update on prospects of using the calorimeter signal in muon triggers in ATLAS is reported. The calibration program of TileCal modules with test beams started in 2001. A brief overview of the calibration and monitoring program of the calorimeter is given.

The central Hadron Calorimeter for CMS Detector is a sampling calorimeter with active medium as scintillator plates interleaved with brass absorber plates. It covers the central pseudorapidity region (|η| < 3.0). The design and construction aspects are reported. The status of construction and assembly of various sub-detectors of HCAL are presented.

The ZEUS Forward Plug Calorimeter performed with an energy resolution of for electrons and for pions. An independent calibration using beam halo muons confirms the results obtained from test beam measurement and ⁶⁰Co-scans within an uncertainty of 8.2%.

A new forward/backward endplug calorimeter, covering the eta range between 1.1 and 3.5, has been installed for CDF Run II at the Fermilab Tevatron. One of the key components is a scintillating strip/wavelength shifting fiber detector located at the electromagnetic shower maximum. Its purpose is to measure the position of electromagnetic particles and to help discern early showering hadronic particles from electromagnetic decays. I will discuss the design, functionality and calibration of the Shower Maximum Detector and present performance results from the beginning of Run II.

The Run IIa integrated calorimetry environment of CDF II comprises: sampling scintillator calorimeters, e.m. pre-shower and shower-maximum detectors (gas based in the central, scintillator based in the forward), crack-filler detectors, radioactive source calibration systems, light pulse calibration systems, dedicated triggers for critical low energy calibrations, new FEE, a Windows NT slow control system, the master online-offline Oracle Database and an online data validation framework, distilled over the previous years of CDF data taking (now based on the CERN Root). The pre-existing central calorimeters are the bridge between the energy and time measurement of the past and current physics runs. New forward calorimeters (the “plugs”), built with the modern scintillating tile-fiber technique, replaced the old gas calorimeters. Together they form an integrated, general-purpose calorimetry system which has been successfully commissioned with the 2000-2001 collider data. The time measurement, before present only in the central hadron, has now been extended the plug hadron calorimeter. To complete the integration in Run IIb (>2004), the central gas pre-shower will be replaced with a tile-fiber detector and the time information will be added also to the e.m. calorimeters. Select jet energy topics are described which show how the CDF II calorimetry has the capability to improve the measurement of the W and the top-quark masses, and to enhance the search for dijet mass peaks in conjunction with b-tagging.

Borexino is a large unsegmented calorimeter featuring 300 tons of liquid scintillator, contained in a 8.5 meter nylon vessel, viewed by 2200 PMTs. The main goal of Borexino is the study, in real time, of low energy solar neutrinos, and in particular, the monoenergetic neutrinos coming from ⁷Be, which is one of the missing links on the solar neutrino problem. The achievement of high radiopurity level, in the order of 10⁻¹⁶g/g of U/Th equivalent, necessary to the detection of the low energy component of the solar neutrino flux, was proved in the Borexino prototype: the Counting Test Facility. The detector is located underground in the Laboratori Nazionali del Gran Sasso in the center of Italy at 3500 meter water equivalent depth. In this paper the science and technology of Borexino are reviewed and its main capabilities are presented.

The MINOS experiment will study neutrino oscillations using the Fermilab Main Injector neutrino beam and both near and far detectors. The detectors are fine-grained sampling calorimeters with 1 inch thick steel absorbers with scintillator as the sampling elements. The scintillator planes are segmented in 4 cm wide strips for tracking and event topology measurements. The very large size of the far detector (26,000m² of scintillator) requires that the cost per unit of detector be kept low. A combination of extruded solid scintillator, wavelength-shifting fibers, multi-pixel PMTs and low-cost electronics meets this challenge. In this talk some important details of the system design will be discussed along with test results from fabrication and initial performance of the first 100 installed far detector planes.

We present in this paper the initial status of a research and development project that will result in the construction and testing of a new prototype electromagnetic calorimeter consisting of a composition of corrugated (accordion shaped) Lead plates and scintillator sheets with embedded fibers for light collection. This novel design is simultaneously addressing a few of the major concerns of collider experiments - projection geometry and hermeticity while keeping mechanical structure relatively simple.

The TESLA linear collider detector is described in a short overview and his unique feature of optimised particle flow measurement is underlined. A review of the technical concept, design and readout of the hadronic tile calorimeter HCAL is followed by a presentation of some actual R&D results for the optimisation of the scintillator tile wavelength shifter system. Concluded is with a discussion on further efforts and plans for a 1m³ HCAL prototype for beam tests and calibration studies.

No abstract received.

After a short description of the ATLAS¹ tile calorimeter front end electronics, the quality control procedure is presented. It is required both to ensure that the electronics match the ATLAS requirements and to face the complexity of any maintenance access in ATLAS. The test benches dedicated to tests of more than 10000 photomultipliers and all 256 entire electronics modules are described, and some results about the radiation hardness are given.

The ATLAS Liquid Argon Front End rad-tolerant electronics chain is described, and the main requirements that have led to today’s architecture are discussed. Performance characteristics of the rad-soft prototype system, based on results obtained from about 6000 read-out channels installed in the test beam, are presented. During the past year, significant progress has been made in the transition to rad-tolerant electronics, which is based on a number of ASICs both in DMILL and DSM technology. Initial measurements on the prototype of the final version of the front-end board are presented.

The Front-End readout system PACE2 for the CMS Preshower detector consists of two chips: Delta is a 32 channel pre-amplifier and shaper that provides low noise, charge to voltage readout for large capacitive silicon sensors over a large dynamic range (up to 400 MIPs); PACE-AM contains a 32-channel wide, 160-cell deep, analog memory with a 32 to 1 multiplexer for serial readout. These chips are designed in .8 μm BiCMOS DMILL radiation tolerant technology. The performance in terms of dynamic range, linearity, noise, peaking time and memory uniformity are presented.

For the readout of the calorimeters of the LHCb experiment at CERN, specific front-end electronics have been designed. In particular, three different front-end analog chips were studied respectively for the ECAL/HCAL, Preshower and Scintillator Pad Detector. We will present the three front-end electronic chains, point out their specific requirements together with their common purpose, and describe the corresponding ASICs.

Upgrades made to the Fermilab Collider to increase luminosity have made it necessary to replace the original CDF sample-and-hold calorimeter electronics with a synchronous system based on the Fermilab QIE series of ASICs. The QIE is an auto-ranging, gated integrator with eight binary-weighted ranges. We have designed and produced a front-end readout system, which digitizes the CDF calorimeter signals, produces trigger information and operates within a two-level trigger system. The architecture of this system and some results from the commissioning period are reported.

In the scope of the upgrade of the HERA collider, the H1 luminosity system was re-built anew. The analog electronics has been designed to transmit photo-multiplier pulses with a repetition rate of 10.4 MHz through 125 m cables, to compensate for the cable skewing and to do a fast shaping avoiding pile-up. The corresponding acquisition is based on custom digitizing cards using the 41 MHz, 12 bits AD9042 ADC chip, a custom 48 Mb/s readout bus, and a commercial computing board (MFCC from C.E.S.) performing fast histogrammation of data. Preliminary results show the ability to readout data at a rate of 0.6 MHz and process them at 0.4 MHz.

The BABAR experiment at the SLAC B-Factory has recorded more than 80 fb⁻¹ of integrated luminosity since 1999. Its electromagnetic calorimeter which consists of 6580 CsI(Tl) crystals has to detect both photons below 20 MeV as well as electrons in the 0.5-9 GeV range with a few percent resolution. Status and performance of the readout electronics including reliability issues and operational experience after the first three years of operation are presented.

The H1 collaboration has performed an upgrade of its data acquisition system for the calorimeters in view of the HERA-II programme. A heterogeneous system based on 29K/VRTX, 68k/OS9 and Vax/VMS was replaced by an integrated Unix cluster composed of two PPC/LynxOS VME boards and Sparc/SunOS stations, using TCP/IP protocols for inter process communication (IPC) and POSIX standards in general. Software transcription consisted of porting three essential functions: hardware setup, calibration datataking with a high serial data through-put and online datataking which emphasizes low frontend deadtime through a three level buffering by means of POSIX threads and messages. Low performance control tasks were programmed in Perl, the user interface has been written in Java. Although the very frontend electronics remain unchanged, a factor two increase in performance was obtained together with a manifestly improved environment for monitoring and diagnostics.

No abstract received.

The D0 Argon purity Test Cell (ATC) measures the O₂-equivalent pollution of a liquid argon sample extracted from the calorimeters. The cell consists in two radioactive sources, α (²⁴¹Am) and β (¹⁰⁶Ru), immersed in liquid argon which produce ionizations. Then, the created charges are drifted by an adjustable electric field. Due to absorption of e⁻ by electronegative impurities, the total collected charge depends on the O₂ pollution. The device is an upgraded version of Run I D0 ATC. Its present sensitivity is estimated to be better than ± 0.15 ppm.

A pulser with adjustable frequency is used to calibrate the electronics. The electric field is ramped step by step between 5 kV cm⁻¹ and 15 kV cm⁻¹. Furthermore, for calibration purpose, the ATC is equipped with a system to pollute a pure Argon sample, with a given amount of O₂.

The setup and method of analysis of α and β measurements will be described. Measurements of the purity of the gas Argon from the three calorimeters (Central, North and South End Cap) will be presented.

The front-end electronics of the DØ calorimeter has undergone a complete redesign to operate successfully with the shorter bunch spacing time at the RunII of the Fermilab Tevatron. After the successful installation of the new electronics, first results of the commissioning, the calibration and the performance of the calorimeter will be presented.

The status of the construction of the ATLAS electromagnetic calorimeter is presented. The quality controls of the module production, their results and consequences are rewiewed. Electron test beam data are used to further assess the uniformity of the modules.

Barrel and endcap modules for the electromagnetic calorimeter of ATLAS have been built and exposed to electron beams of up to 245 GeV. Their performance in terms of noise, energy and position resolution is discussed and compared with Monte Carlo simulations.

The construction of the ATLAS Hadronic Endcap Calorimeter is nearing completion. Beam tests of the series modules have been completed. The performance of the modules yields a resolution for electrons of and for pions of , where ⊕ denotes a quadratic sum. The uniformity and linearity have been verified. The details of the electronic readout chain are well understood and allow precision predictions for the performance of the calorimeter under the final ATLAS operating conditions.

Serial modules of the ATLAS hadronic end-cap calorimeter have been successfully tested in particle beams at CERN in 2000 and 2001. Main performance parameters of calorimeter modules, obtained by analyses of electron, muon and charged pion data, are presented. Detailed comparisons of experimental results with predictions, based on Geant3 simulations, are done.

A calorimetric detector based on ionization has been employed as a low-angle luminosity monitor for the parity violation experiment E158¹ at SLAC. The experiment utilizes a 50 GeV polarized electron beam on a liquid hydrogen target. The detector looks at high energy Mott and Moller scattered electrons, with a per pulse flux of 4 × 10⁸ particles. This large signal allows the device to serve the dual role of monitoring target density fluctuations, as well as detecting false asymmetries, In the first physics run of the experiment, the detector has achieved a per-pulse intensity asymmetry resolution of 170 parts per million. The linearity of the device also has been verified to ≤1%.

The impact of the jet energy and direction measurement performances is studied through the 4 jets (W pair production) at LEP2. Emphasis is put on the sensitivity of the algorithms to the calibration of the jet component and to the the jet fragmentation modelling. The implication upon the systematics for the main physics channels are derived.

The physics programme for a coming electron linear collider is dominated by events with final states containing many jets, dijets from H, W, Z. We contend that, in the energy range under consideration, the best approach is to optimise the independent measurement of the tracks in the tracker, the photons in the electromagnetic calorimeter and the neutral hadrons in the calorimetry, together with a good lepton identification. This can be achieved with a good tracker and a high granularity calorimetry providing particle separation, through an efficient energy flow algorithm. But we do not contend that this is a universal panacea. Following that programme from the calorimetric side on hardware and software issues is the goal of the CALICE collaboration.

The jet calibration of the Liquid-Argon-Calorimeter of the H1 Detector at HERA is described. In the measurement of high jet transverse energies systematic uncertainties as low as 2% can be reached in deep inelastic scattering with a high photon virtuality (Q²) and in photoproduction. Furthermore, the concept of a new energy weighting scheme of H1 is presented. First applications with a high Q² neutral current deep inelastic scattering sample show that the resolution of the balance in transverse momentum between the hadronic system and the electron is improved.

A much improved determination of the transverse energy of jets has been carried out in ZEUS, using a correction procedure based on two independent methods. The first is based on a combination of tracking and calorimeter information which optimises the resolution of reconstructed kinematic variables. The conservation of energy and momentum in neutral current deep inelastic e⁺p scattering events is exploited to determine the energy corrections by balancing the kinematic quantities of the scattered positron with those of the hadronic final state. The method has been independently applied to data and simulated events. The second method uses calorimeter cells as inputs to the jet algorithm. Simulated events are then used to provide a correction for the energy loss due to inactive material in front of the calorimeter. A detailed comparison of the jet transverse energy and the transverse energy of tracks in a cone around the jet provides the final correction. This procedure relies on an accurate simulation of charged tracks and so is less reliant on simulating the energy loss of neutral particles in inactive material. Final comparisons of the data and simulated events for both methods allow an uncertainty ±1% to be assigned to the jet energy scale.

Jet clustering algorithms which have been developed for the analysis of Run II data are presented and compared. A shortcoming of the new cone algorithm is presented and discussed in the framework of an analytic model.

Multiple low–p_T (min-bias) interactions within a beam crossing at a high luminosity hadronic collider contribute to pile-up noise in the calorimetric measurements of jets. I show how to minimize this noise by taking advantage of correlations in these background events. Substantial reductions are possible.

This paper presents recent results, current problems, and possible solutions for analyses that use both the k_T and cone jet algorithms. Hadronization of final-state partons can improve the level of agreement between NLO QCD predictions and the inclusive jet cross section observed using k_T jets. The dijet transverse thrust analysis, which also uses k_T, provides a jet measurement in two kinematic regions where NLO has little predictive power. The results suggest both resummation and higher-order predictions can improve the theory in their respective regions. Finally, the cone jet algorithm, including the recent “midpoint” improvement, contains an inherent weakness, as identified by CDF (see Matthais Toennesmann’s presentation in this session). The DØ Collaboration is exploring the suggested modification to this algorithm, in the hope that both experiments will use a common algorithm in Run II of the Tevatron.

The Jet Measurement in OPAL is summerised. In OPAL, jet is reconstructed from the energy flow “object” which are the output of the energy flow algorithm. The algorithm tries to subtract track momentum from calorimeter energy and tries to do software compensation. For better measurement of particle mass such as Z⁰ W or H⁰, jet re-association technique is used. The detail of energy flow algorithm and jet re-association is described.

The most relevant techniques used by DELPHI to identify jets in multihadronic final states are reviewed. The performance of jet reconstruction algorithms is analysed together with the additional use of energy and momentum conservation in order to allow for a precise reconstruction of the event kinematics. Also jet flavour tagging methods are summarised. Applications in some analyses like searches for new particles such as Higgs bosons, W mass physics and QCD studies are presented.

The status of R&D at Argonne National Laboratory on the design of a future Hadron Calorimeter (HCAL) is presented here. This includes work done on optimization of the HCAL for best energy resolution for jets reconstructed using E-flow techniques and initial tests of the use of Resistive Plate Chambers (RPCs) as a calorimeter readout device.

The elementary constituents of hadronic matter (quarks, anti-quarks, gluons) manifest themselves experimentally in the form of jets of particles. We investigate the precision with which the energy of these fragmenting objects can be measured. The relative importance of the instrumental measurement precision and of the jet algorithm is assessed. We also evaluate the “energy flow” method, in which the information from a charged-particle tracker is combined with that from a calorimeter in order to improve the jet energy resolution.

The paper begins by defining the role of calorimetry in high energy physics experiments. Then the status of the present state of the art is briefly examined. Recent improvements in calorimetry, e.g. “energy flow” are examined, particularly in the light of fundamental limitations in the calorimetric technique. Directions of possible future developments in calorimetry as new facilities are planned and designed are examined.

The measurement methodologies of astrophysics experiments reflect the enormous variation of the astrophysical radiation itself. The diverse nature of the astrophysical radiation, e.g. cosmic rays, electromagnetic radiation, and neutrinos, is further complicated by the enormous span in energy, from the 1.95K relic neutrino background to cosmic rays with energy > 10²⁰ eV. The measurement of gravity waves and search for dark matter constituents are also of astrophysical interest. Thus, the experimental techniques employed to determine the energy of the incident particles are strongly dependent upon the specific particles and energy range to be measured. This paper summarizes some of the calorimetric methodologies and measurements planned by future astrophysics experiments. A focus will be placed on the measurement of higher energy astrophysical radiation. Specifically, future cosmic ray, gamma ray, and neutrino experiments will be discussed.

Conference Pictures.

AUTHOR INDEX.

LIST OF PARTICIPANTS.