Showing papers on "Calorimeter published in 2014"

Electron and photon energy calibration with the ATLAS detector using LHC Run 1 data

Abstract: This paper presents the electron and photon energy calibration achieved with the ATLAS detector using about 25 fb(-1) of LHC proton-proton collision data taken at centre-of-mass energies of root s = 7 and 8 TeV. The reconstruction of electron and photon energies is optimised using multivariate algorithms. The response of the calorimeter layers is equalised in data and simulation, and the longitudinal profile of the electromagnetic showers is exploited to estimate the passive material in front of the calorimeter and reoptimise the detector simulation. After all corrections, the Z resonance is used to set the absolute energy scale. For electrons from Z decays, the achieved calibration is typically accurate to 0.05% in most of the detector acceptance, rising to 0.2% in regions with large amounts of passive material. The remaining inaccuracy is less than 0.2-1% for electrons with a transverse energy of 10 GeV, and is on average 0.3% for photons. The detector resolution is determined with a relative inaccuracy of less than 10% for electrons and photons up to 60 GeV transverse energy, rising to 40% for transverse energies above 500 GeV.

Progress and New Directions in Calorimetry: A 2014 Perspective

Abstract: To assess progress in high-temperature calorimetry over the past eighteen years, this feature article discusses both technical developments and new areas of application, with primary emphasis on high-temperature oxide melt solution calorimetry. The Calvet calorimeter for such measurements is now commercially available, and an extensive table of enthalpies of drop solution (sample at room temperature dropped into molten oxide solvent in calorimeter and dissolved) is provided for the user community. New developments in methodology are described and applications to nanomaterials, to nitrides and other monoxide materials, and to lanthanides and actinides are given.

Heat generation in high power prismatic Li-ion battery cell with LiMnNiCoO2 cathode material

Abstract: SUMMARY While in use, battery modules and battery packs generate large amounts of heat, which needs to be accounted for. The main challenge in battery thermal management is the correct estimation of heat generation in the battery cell during charging/discharging. In this paper, a method to calculate accurate heat generation in one individual cell is provided. The heat generation is calculated by measuring the overpotential resistances with four different methods and entropic heat generation in the cell. The effect and contribution of entropic heat generation towards the total heat generation in the cell are also calculated and measured. Finally, calorimeter tests are carried out to compare the calculated and measured heat generation. The results indicate that except for direct current resistance measured by impedance spectroscopy, all the overpotential resistances are very close to each other. Copyright © 2014 John Wiley & Sons, Ltd.

Comparison and validation of methods for estimating heat generation rate of large-format lithium-ion batteries

Abstract: The heat generation rate of a large-format 25 Ah lithium-ion battery is studied through estimating each term of the Bernardi model. The term for the reversible heat is estimated from the entropy coefficient and compared with the result from the calorimetric method. The term for the irreversible heat is estimated from the intermittent current method, the V–I characteristics method and a newly developed energy method. Using the obtained heat generation rates, the average cell temperature rise under 1C charge/discharge is calculated and validated against the results measured in an accelerating rate calorimeter (ARC). It is found that the intermittent current method with an appropriate interval and the V–I characteristics method using a pouch cell yield close agreement, while the energy method is less accurate. A number of techniques are found to be effective in circumventing the difficulties encountered in estimating the heat generation rate for large-format lithium-ion batteries. A pouch cell, using the same electrode as the 25 Ah cell but with much reduced capacity (288 mAh), is employed to avoid the significant temperature rise in the V–I characteristics method. The first-order inertial system is utilized to correct the delay in the surface temperature rise relative to the internal heat generation. Twelve thermocouples are used to account for the temperature distribution.

Acoustic Emission and Low-Temperature Calorimetry Study of Freeze and Thaw Behavior in Cementitious Materials Exposed to Sodium Chloride Salt

Abstract: This paper describes a series of experiments that were performed to assess the freeze-thaw behavior of mortar specimens exposed to sodium chloride (NaCl) solutions. A low-temperature longitudinal guarded comparative calorimeter was used to perform cyclic freeze-thaw testing on mortar specimens saturated with NaCl solutions. Heat flow and acoustic emission activity were monitored during the freeze-thaw experiment to detect ice formation and cracking. Although the conventional water-NaCl phase diagram would suggest that no freezing or damage would occur in specimens saturated with 15% and 23.3% NaCl solution by mass within the applied freeze-thaw temperature range, damage was observed. For these specimens, an additional heat flow peak attributed to an unexpected phase change, accompanied by acoustic activity, was detected at a temperature higher than the expected freezing point. For better understanding of the source of this damage, a low-temperature differential scanning calorimeter was used to investigate...

High-resolution thermal imaging with a combination of nano-focus X-ray diffraction and ultra-fast chip calorimetry.

Abstract: A microelectromechanical-systems-based calorimeter designed for use on a synchrotron nano-focused X-ray beamline is described This instrument allows quantitative DC and AC calorimetric measurements over a broad range of heating/cooling rates (≤100000 K s−1) and temperature modulation frequencies (≤1 kHz) The calorimeter was used for high-resolution thermal imaging of nanogram-sized samples subjected to X-ray-induced heating For a 46 ng indium particle, the measured temperature rise reaches ∼02 K, and is directly correlated to the X-ray absorption Thermal imaging can be useful for studies of heterogeneous materials exhibiting physical and/or chemical transformations Moreover, the technique can be extended to three-dimensional thermal nanotomography

The electromagnetic performance of the RD52 fiber calorimeter

Abstract: The RD52 calorimeter is an instrument intended to detect both electromagnetic and hadronic showers, as well as muons, using the dual-readout principle. Scintillation and Cherenkov light provide the two signals which, in combination, allow for superior hadronic performance. In this paper, we report on the electromagnetic performance of this instrument, and compare this performance with that of other calorimeters that were constructed with similar goals in mind.

Results on damage induced by high-energy protons in LYSO calorimeter crystals

Abstract: Lutetium-Yttrium Orthosilicate doped with Cerium (LYSO), as a bright scintillating crystal, is a candidate for calorimetry applications in strong ionising-radiation fields and large high-energy hadron fluences are expected at the CERN Large Hadron Collider after the planned High-Luminosity upgrade There, proton–proton collisions will produce fast hadron fluences up to ~ 5 × 10 14 cm − 2 in the large-rapidity regions of the calorimeters The performance of LYSO has been investigated, after exposure to different fluences of 24 GeV c−1 protons Measured changes in optical transmission as a function of proton fluence are presented, and the evolution over time due to spontaneous recovery at room temperature is studied The activation of materials will also be an issue in the described environment Studies of the ambient dose induced by LYSO and its evolution with time, in comparison with other scintillating crystals, have also been performed through measurements and FLUKA simulations

Measurements of wood pellets self-heating kinetic parameters using isothermal calorimetry

Abstract: Wood pellets release heat and gases during storage. A TAM air isothermal calorimeter was used to measure the rate of heat release by bulk pellets at temperatures ranging from 30 to 50 °C. The results showed that self-heating rate at the tested temperature range strongly depended on the reaction temperature and the age of pellets. Heat release rate increased as the reaction temperature increased but the rate was not sensitive to pellets moisture content. The activation energy of the self-heating reaction increased with the age of pellets. A simple global kinetic model for self-heating was developed from the experimental data. The model can be applied to simulate the self-heating process in pellets storage containers at different storage temperatures and age of stored pellets.

Calorimetry: Fundamentals, Instrumentation and Applications

Abstract: INTRODUCTION: Calorimetry: Definition, Application Fields and Units Definition of Calorimetry Application Fields for Calorimetry First Example from Life Sciences Second Example from Material Science Third Example from Legal Metrology Units PART I: Fundamentals of Calorimetry METHODS OF CALORIMETRY Compensation of the Thermal Effect Measurement of Temperature Differences Summary of Measuring Principles MEASURING INSTRUMENTS Measurement of Amount of Substance Measurement of Electric Quantities Measurement of Temperatures Chemical Composition FUNDAMENTALS OF THERMODYNAMICS States and Processes Phases and Phase Transitions HEAT TRANSPORT PHENOMENA Heat Conduction Convection Heat Radiation Heat Transfer Entropy Increase during Heat Exchange Conclusions Concerning Calorimetry SURROUNDINGS AND OPERATION CONDITIONS The Isothermal Condition The Isoperibol Condition The Adiabatic Condition The Scanning Condition MEASUREMENT AND EVALUATION Consequences of Temperature Relaxation within the Sample Typical Results from Different Calorimeters Reconstruction of the True Sample Heat Flow Rate from the Measured Function Special Evaluations Determination of the Measurement Uncertainty PART II: Practice of Calorimetry CALORIMETERS Functional Components and Accessories Heating Methods Cooling Methods Comments on Control Systems Thermostats On the Classification of Calorimeters On the Characterization of Calorimeters Isothermal Calorimeters Calorimeters with Heat Exchange between Sample and Surroundings Adiabatic Calorimeters Other Calorimeters RECENT DEVELOPMENTS Microchip Calorimetry Microchip Calorimetry Extreme Ranges of State Calorimetry as an Analytical and Diagnostic Tool CALORIMETRIC MEASUREMENTS: GUIDELINES AND APPLICATIONS General Considerations Guidelines to Calorimetric Measurements Calorimetric Applications Index

Vapor–Liquid Phase Equilibria and Excess Thermal Properties of Binary Mixtures of Ethylsulfate-Based Ionic Liquids with Water: New Experimental Data, Correlations, and Predictions

Abstract: This work reports the measurements of the vapor pressure, excess enthalpy of mixing, and molar heat capacity for selected {ionic liquid + water} binary systems. The studied ionic liquids are 1-ethyl-1-methylpiperidinium ethylsulfate, 1-ethyl-1-methylpyrrolidinium ethylsulfate, and 1-ethyl-1-methylmorpholinium ethylsulfate. The isothermal vapor–liquid phase equilibria have been measured by an ebulliometric method within temperature range from 338.15 to 368.15 K and pressure up to the vapor pressure of pure water. Excess enthalpy was measured with an isothermal titration calorimeter at temperature 298.15 K. Heat capacities have been determined within the temperature range from 288.15 to 383.15 K. The influence of temperature and composition as well as the structure of cation of the studied ionic liquids on the measured properties was assessed. The Redlich–Kister correlation was used in order to reduce the huge number of data points collected. Finally, thermodynamic modeling with molecular-based PC-SAFT equa...

Loss Definition of Electric Drives by a Calorimetric System With Data Processing

Abstract: An accurate measurement of power or heat losses of high-efficiency electrical devices is difficult with input and output powers. In the calorimetric method, these losses are measured directly. In this paper, a functional heat loss measurement concept with adequate data processing methods is suggested for heat losses up to 2 kW. Such a heat loss range can be applied to present-day power electronic converters with the rated power of up to 110 kW and motors up to 37 kW. The measurement system does not require a complex mechanical structure or a large footprint area on the measurement site. The concept is scalable to different sizes. New features to the balance type calorimeter data processing are introduced. These include a mass flow correction, a technique to detect the thermal equilibrium, and a method to correct measured heat losses to improve the measurement repeatability and reduce the measurement uncertainty. The measurement uncertainty of the proposed calorimetric concept is 0.4%. Laboratory measurements are carried out both for a commercial frequency converter and an electric motor. These are measured at the same time with two calorimeters. The losses of these devices are measured both by the input-output and calorimetric methods.

The time structure of hadronic showers in highly granular calorimeters with tungsten and steel absorbers

Abstract: The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

Monitoring and data quality assessment of the ATLAS liquid argon calorimeter

Abstract: The liquid argon calorimeter is a key component of the ATLAS detector installed at the CERN Large Hadron Collider. The primary purpose of this calorimeter is the measurement of electron and photon kinematic properties. It also provides a crucial input for measuring jets and missing transverse momentum. An advanced data monitoring procedure was designed to quickly identify issues that would affect detector performance and ensure that only the best quality data are used for physics analysis. This article presents the validation procedure developed during the 2011 and 2012 LHC data-taking periods, in which more than 98% of the proton-proton luminosity recorded by ATLAS at a centre-of-mass energy of 7–8 TeV had calorimeter data quality suitable for physics analysis.

Calibration of a T-History calorimeter to measure enthalpy curves of phase change materials in the temperature range from 40 to 200??C

Abstract: Thermal energy storage using phase change materials (PCMs) provides high storage capacities in small temperature ranges. For the design of efficient latent heat storage, the enthalpy curve of a PCM has to be measured with high precision. Measurements are most commonly performed with differential scanning calorimetry (DSC). The T-History method, however, proved to be favourable for the characterization of typical PCMs due to large samples and a measuring procedure close to conditions found in applications. As T-History calorimeters are usually individual constructions, performing a careful calibration procedure is decisive to ensure optimal measuring accuracy. We report in this paper on the calibration of a T-History calorimeter with a working range from 40 to 200??C that was designed and built at our institute. A three-part procedure, consisting of an indium calibration, a measurement of the specific heat of copper and measurements of three solid?liquid PCMs (stearic acid, dimethyl terephthalate and d-mannitol), was performed and an advanced procedure for the correction of enthalpy curves was developed. When comparing T-History enthalpy curves to literature data and DSC step measurements, good agreement within the uncertainty limits demanded by RAL testing specifications was obtained. Thus, our design of a T-History calorimeter together with the developed calibration procedure provides the measuring accuracy that is required to identify the most suitable PCM for a given application. In addition, the dependence of the enthalpy curve on the sample size can be analysed by comparing results obtained with T-History and DSC and the behaviour of the bulk material in real applications can be predicted.

Evaluating Models for Predicting Full-Scale Fire Behaviour of Polyurethane Foam Using Cone Calorimeter Data

Abstract: Two models that can be used to predict full-scale heat release rates of polyurethane foam slabs were evaluated in this study. Predictions were compared with results of furniture calorimeter tests of 10 cm thick polyurethane foam specimens which were ignited in the centre or on the edge. Furniture calorimeter results indicated that peak heat release rates and fire growth rates were higher during centre ignition tests than edge ignition tests. For both situations, the growth phase of the heat release rate curves measured in the full-scale tests was successfully predicted using t2 design fires; the choice of a specific t2 fire depended on the surface area of the specimen and ignition location. A model originally developed during the European Combustion Behaviour of Upholstered Furniture (CBUF) project was also evaluated using heat release rate data from cone calorimeter tests and flame area burning rates measured using infrared video records of the furniture calorimeter tests. This model was able to successfully predict the initial growth phase of the fires and predictions of peak heat release rates were within 17% of measured values. The model had less success in predicting heat release rates later in the growth phase and during the decay phase of the fires, and did not appear to capture all of the physics of the full-scale tests, in particular foam melting and subsequent liquid pool burning. As the model did show promise, future work is planned to address these shortcomings and to develop improved flame spread models for polyurethane foam.

A Novel On-chip Three-dimensional Micromachined Calorimeter with Fully Enclosed and Suspended Thin-film Chamber for Thermal Characterization of Liquid Samples

Abstract: A microfabricated calorimeter (μ-calorimeter) with an enclosed reaction chamber is presented. The 3D micromachined reaction chamber is capable of analyzing liquid samples with volume of 200 nl. The thin film low-stress silicon nitride membrane is used to reduce thermal mass of the calorimeter and increase the sensitivity of system. The μ-calorimeter has been designed to perform DC and AC calorimetry, thermal wave analysis, and differential scanning calorimetry. The μ-calorimeter fabricated with an integrated heater and a temperature sensor on opposite sides of the reaction chamber allows to perform thermal diffusivity and specific heat measurements on liquid samples with same device. Measurement results for diffusivity and heat capacitance using time delay method and thermal wave analysis are presented.

The LYSO crystal calorimeter for the Mu2e experiment

Abstract: The Mu2e experiment at Fermilab searches the neutrino-less conversion of the muon into electron in the field of an Aluminum nucleus. If such a process will be observed, it will be a proof of the charged-lepton-flavor-violation (cLFV), otherwise Mu2e will set an upper limit of R_μe < 6 × 10^(−17) @ 90% C.L. (which represents an improvement by 3–4 order of magnitude over the existing limit). The Mu2e detector apparatus consists of a magnetic spectrometer, devoted to the measurement of the electrons momentum, and an electromagnetic calorimeter (EMC) which provides an independent measurement of the electron energy, time and position, used for validating or rejecting candidate tracks selected by the tracking system. In this paper, we describe the baseline project of the EMC and present results in terms of performances and R&D.

Application of a novel type of adiabatic scanning calorimeter for high-resolution thermal data near the melting point of gallium

Abstract: A novel type of adiabatic scanning calorimeter (ASC) based on Peltier elements (PEs) is used to obtain high-resolution enthalpy and heat capacity data on the melting transition of gallium. The accuracy of the specific heat capacity and specific enthalpy is about 2 %, for a sub-mK temperature resolution. The simultaneously determined equilibrium specific heat capacity and specific enthalpy are used to determine the heat of fusion and the purity. In addition, the use of the PE-based ASC as a classical heat step calorimeter and as a constant rate (DSC-type) calorimeter is discussed. A comparison of the ASC results with literature data and DSC data shows the advantages of ASC for the study of phase transitions.

Calorimetric measurement of absolute terahertz power at the sub-microwatt level.

Abstract: We developed a calorimeter for determining absolute terahertz (THz) power. The calorimeter is based on a DC substitution method using an isothermal temperature-control technique. A neutral-density optical filter glass was used as a volume absorber, and its THz absorption was evaluated by a time-domain spectrometer. Highly sensitive measurement of the absolute THz power was experimentally achieved in the range from the submicrowatt to microwatt level at room temperature. Power measurement of a continuous-wave THz source using a photomixer was demonstrated. This calorimeter is expected to demonstrate the traceability of THz power at a submicrowatt level.

The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

Abstract: The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

Absolute x-ray dosimetry on a synchrotron medical beam line with a graphite calorimeter.

Abstract: Purpose: The absolute dose rate of the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter. The calorimetry results were compared to measurements from the existing free-air chamber, to provide a robust determination of the absolute dose in the synchrotron beam and provide confidence in the first implementation of a graphite calorimeter on a synchrotron medical beam line. Methods: The graphite calorimeter has a core which rises in temperature when irradiated by the beam. A collimated x-ray beam from the synchrotron with well-defined edges was used to partially irradiate the core. Two filtration sets were used, one corresponding to an average beam energy of about 80 keV, with dose rate about 50 Gy/s, and the second filtration set corresponding to average beam energy of 90 keV, with dose rate about 20 Gy/s. The temperature rise from this beam was measured by a calibrated thermistor embedded in the core which was then converted to absorbed dose to graphite by multiplying the rise in temperature by the specific heat capacity for graphite and the ratio of cross-sectional areas of the core and beam. Conversion of the measured absorbed dose to graphite to absorbed dose to water wasmore » achieved using Monte Carlo calculations with the EGSnrc code. The air kerma measurements from the free-air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. Results: Absolute measurements of the IMBL dose rate were made using the graphite calorimeter and compared to measurements with the free-air chamber. The measurements were at three different depths in graphite and two different filtrations. The calorimetry measurements at depths in graphite show agreement within 1% with free-air chamber measurements, when converted to absorbed dose to water. The calorimetry at the surface and free-air chamber results show agreement of order 3% when converted to absorbed dose to water. The combined standard uncertainty is 3.9%. Conclusions: The good agreement of the graphite calorimeter and free-air chamber results indicates that both devices are performing as expected. Further investigations at higher dose rates than 50 Gy/s are planned. At higher dose rates, recombination effects for the free-air chamber are much higher and expected to lead to much larger uncertainties. Since the graphite calorimeter does not have problems associated with dose rate, it is an appropriate primary standard detector for the synchrotron IMBL x rays and is the more accurate dosimeter for the higher dose rates expected in radiotherapy applications.« less

The CMS ECAL performance with examples

Abstract: The electromagnetic calorimeter (ECAL) of the CMS experiment at the CERN Large Hadron Collider is a hermetic, fine grained, homogeneous calorimeter containing 75848 lead tungstate crystals, completed by a silicon preshower installed in front of the endcaps. The main characteristics of the ECAL are reviewed. These include the challenges of calibration and triggering in the LHC environment, as well as the reconstruction and identification of photons and electrons. Several results achieved by the CMS experiment particularly exploit the ECAL excellent performance, here illustrated with reference to specific examples, comprising the Higgs boson search and characterization in the H → γγ and H → ZZ(*) decay channels and the search for non-standard phenomena such as high-mass gauge bosons decaying into electrons and long-lived particles with delayed signals in the calorimeter.