Showing papers on "Calorimeter published in 2020"

Reaching the ultimate energy resolution of a quantum detector.

Abstract: Quantum calorimetry, the thermal measurement of quanta, is a method of choice for ultrasensitive radiation detection ranging from microwaves to gamma rays. The fundamental temperature fluctuations of the calorimeter, dictated by the coupling of it to the heat bath, set the ultimate lower bound of its energy resolution. Here we reach this limit of fundamental equilibrium fluctuations of temperature in a nanoscale electron calorimeter, exchanging energy with the phonon bath at very low temperatures. The approach allows noninvasive measurement of energy transport in superconducting quantum circuits in the microwave regime with high efficiency, opening the way, for instance, to observe quantum jumps, detecting their energy to tackle central questions in quantum thermodynamics.

Getting High: High Fidelity Simulation of High Granularity Calorimeters with High Speed

Abstract: Accurate simulation of physical processes is crucial for the success of modern particle physics. However, simulating the development and interaction of particle showers with calorimeter detectors is a time consuming process and drives the computing needs of large experiments at the LHC and future colliders. Recently, generative machine learning models based on deep neural networks have shown promise in speeding up this task by several orders of magnitude. We investigate the use of a new architecture -- the Bounded Information Bottleneck Autoencoder -- for modelling electromagnetic showers in the central region of the Silicon-Tungsten calorimeter of the proposed International Large Detector. Combined with a novel second post-processing network, this approach achieves an accurate simulation of differential distributions including for the first time the shape of the minimum-ionizing-particle peak compared to a full GEANT4 simulation for a high-granularity calorimeter with 27k simulated channels. The results are validated by comparing to established architectures. Our results further strengthen the case of using generative networks for fast simulation and demonstrate that physically relevant differential distributions can be described with high accuracy.

Enhanced Electrocaloric Effect in 0.73Pb(Mg1/3Nb2/3)O3-0.27PbTiO3 Single Crystals via Direct Measurement

Abstract: Electrocaloric properties of [110] and [111] oriented 0.73Pb(Mg1/3Nb2/3)O3-0.27PbTiO3 single crystals were studied in the temperature range of 293–423 K. The Maxwell relations and the Landau–Ginsburg–Devonshire (LGD) phenomenological theory were employed as the indirect method to calculate the electrocaloric properties, while a high-resolution calorimeter was used to measure the adiabatic temperature change of the electrocaloric effect (ECE) directly. The results indicate that the directly measured temperature changes of ΔT > 2.5 K at room temperature were procured when the applied electric field was reversed from 1 MV/m to −1 MV/m, which are larger than those deduced pursuant to the Maxwell relation, and even larger than those calculated using the LGD theory in the temperature range of 293–~380 K.

Thermal safety diagram for lithium-ion battery using single-crystal and polycrystalline particles LiNi0.8Co0.1Mn0.1O2

Abstract: Thermal runaway of lithium-ion battery (LIB) depends not only on the chemical composition of cathode materials but also on grain boundary. However, despite many studies on thermal stability of cathode materials to date, few safety diagrams of thermal runaway in full cells have been reported. In this study, the thermal safety diagram is compared in the full cell by using single-crystal and polycrystalline particles LiNi0.8Co0.1Mn0.1O2 (NCM 811) as cathode material and natural graphite (NG) as anode material. A thermal safety diagram is made using a differential scanning calorimetry (DSC) by using an all-inclusive cell, which consists of all LIB components. Since a thermal runaway reaction is a series of elementary reactions, it is determined using the Friedman differential isoconversional method. Thermal runaway prediction results obtained using DSC data are verified using an acceleration rate calorimeter (ARC). The prediction results nearly match the verification results of ARC measurements, and it is clarified that the full cell using single-crystal particles NCM 811 as the cathode material has higher thermal safety than that using polycrystalline particles NCM 811.

Thermal kinetics on exothermic reactions of a commercial LiCoO2 18650 lithium-ion battery and its components used in electric vehicles: A review

Abstract: A review gathering available results on the chemical kinetics in literature for the commercial 18650 lithium-ion batteries containing cathode material of LiCoO2 and related components is summarized and discussed. Most of these kinetic parameters derived from adiabatic and heat-flow calorimeter, some few of them with the fitting of electrochemical-thermal model associated with data of accelerating rate calorimeter. However, due to the complexity of solid-state reaction involving both anode and cathode as well as the difficulty to determine the reaction mechanism function by thermal analysis on the solid electrode, most of the interpretation of calorimetric data set the order to be unity for simplicity. Kinetics-based heat rates under thermal abuses encompass the decomposition of solid electrolyte interface (stage III from 85 to 120 °C), reaction of LixC6 with electrolyte (stage IV from 120 to 170 °C), reaction of LixCoO2 with electrolyte (stage V from 170 to 200 °C), decomposition of LixCoO2 (stage VI > 200 °C), decomposition of solvent (stage VI > 200 °C) induced by internal short, and auto-ignition of solvent (stage VI > 200 °C). To clearly capture the distinctive features of these kinetic behaviors, the standard deviations adopted by the American Society for Testing and Materials E2781 and International Confederation for Thermal Analysis and Calorimetry are applied to enhance the accuracy and precision of the kinetic parameters. A diagram integrating all the Ea and log A values of LiCoO2 battery and its components is depicted, in which a newly phenomenon of compensation effect has been discovered. The linear equation of log A versus Ea tells the truth that some large errors existed in the data acquisition of kinetic parameters. Taking and comparing individually the average kinetic parameters from the decomposition of SEI, reaction of LixC6 with electrolyte, reaction of LixCoO2 with electrolyte to the whole battery, it is noteworthy that the chemical kinetics of the LiCoO2 battery is next door to that of LixCoO2 with electrolyte in n-th order reactions. The autocatalytic model II in Ea versus log A diagram seems to have the biggest deviations. The paradoxical model between the n-th order and autocatalytic type regarding the reaction of LixCoO2 with electrolyte exists and has not been exactly solved. Practically, some unimaginable disagreement among parameters of Ea and logA (sec−1 M1-n) are as yet unsettled, which reveals that the more extensive studies are needed to resolve the existing disputes. For the near future, a breakthrough of exceedingly better technology for acquiring the accurate chemical kinetics of a LiCoO2 battery and its ingredients will be expected earnestly.

Characterization of reaction enthalpy and kinetics in a microscale flow platform

Abstract: We report an isothermal flow calorimeter for characterization of reaction enthalpy and kinetics. The platform consists of a thermoelectric element and a glass–silicon microreactor to measure heat flux and an inline IR spectrometer to monitor reaction conversion. The thermally insulated assembly is calibrated with a thin film heater placed between the microreactor and the thermoelectric element. Without any reconfiguration of hardware, the setup can also be used to efficiently characterize reaction kinetics in transient flow experiments. We tested the calorimeter with hydrolysis of acetic anhydride as a model reaction. We determined the exothermic reaction enthalpy and the endothermic heat of mixing of the reagent to be −63 ± 3.0 kJ mol−1 and +8.8 ± 2.1 kJ mol−1 respectively, in good agreement with literature values and theoretical predictions. Following calorimetry studies, we investigated reaction kinetics by applying carefully controlled residence time ramps at four different temperatures, and we obtained kinetic rate constants of 0.129 min−1 up to 0.522 min−1 for temperatures between 20 °C and 56.3 °C, also fitting well with data reported in the literature.

New perspectives on segmented crystal calorimeters for future colliders

Abstract: Crystal calorimeters have a long history of pushing the frontier on high-resolution electromagnetic (EM) calorimetry. We explore in this paper major innovations in collider detector performance that can be achieved with crystal calorimetry when longitudinal segmentation and dual-readout capabilities are combined with a new high EM resolution approach to PFA in multi-jet events, such as $e^+e^+\rightarrow HZ$ events in all-hadronic final-states at Higgs factories. We demonstrate a new technique for pre-processing $\pi^0$ momenta through combinatoric di-photon pairing in advance of applying jet algorithms. This procedure significantly reduces $\pi^0$ photon splitting across jets in multi-jet events. The correct photon-to-jet assignment efficiency improves by a factor of 3 with a $3\%/\sqrt{E}$ EM resolution. In addition, the technique of bremsstrahlung photon recovery significantly improves electron momentum measurements. A high EM resolution calorimeter increases the Z boson recoil mass resolution in Higgstrahlung events for decays into electron pairs to 80% of that for muon pairs. We present the design and optimization of a highly segmented crystal detector concept that achieves the required energy resolution, and a time resolution better than 30 ps providing exceptional particle identification capabilities. We demonstrate that, contrary to previous detector designs that suffered from large neutral hadron resolution degradation from one interaction length of crystals in front of a sampling hadron calorimeter, the implementation of dual-readout on crystals permits to achieve a resolution better than $30\%/\sqrt{E}\oplus 2\%$ for neutral hadrons. Our studies find that the integration of crystal calorimetry into future Higgs factory collider detectors can open new perspectives by yielding the highest level of combined EM and neutral hadron resolution in the PFA paradigm.

Reaction hazard and mechanism study of H2O2 oxidation of 2-butanol to methyl ethyl ketone using DSC, Phi-TEC II and GC-MS

Abstract: Methyl ethyl ketone (MEK) oxidation via H2O2 with tungsten-based polyoxometalate catalysts has gained much attention with an ever-growing body of knowledge focusing on the development of environmentally benign processes in chemical industry. In this study, two calorimetry techniques, differential scanning calorimetry (DSC) and Phi-TEC II adiabatic calorimetry, were employed to analyze the thermal hazards associated with the 2-butanol oxidation reaction system. Hydrogen peroxide was the oxidant and a tungsten-based polyoxometalate as the catalyst. Gas chromatography-mass spectrometry was used for identification of the organic products. Important thermal kinetic data were obtained including “onset” temperature, heat of reaction, adiabatic temperature rise and self-heat rate. From DSC results, three exothermic peaks were detected with a total heat generation of approximately 1.26 kJ/g sufficiently to induce a thermal runaway. Possible reaction pathway for three stages were proposed based on both DSC and GC-MS results. One exotherm was detected by Phi-TEC II calorimeter and the pressure versus temperature profile together with the DSC and GC-MS data demonstrate the complexity of 2-butanol reaction system under both thermal screening and adiabatic conditions.

Calibration and performance of the LHCb calorimeters in Run 1 and 2 at the LHC

Abstract: The calibration and performance of the LHCb Calorimeter system in Run 1 and 2 at the LHC are described. After a brief description of the sub-detectors and of their role in the trigger, the calibration methods used for each part of the system are reviewed. The changes which occurred with the increase of beam energy in Run 2 are explained. The performances of the calorimetry for $\gamma$ and $\pi^0$ are detailed. A few results from collisions recorded at $\sqrt {s}$ = 7, 8 and 13 TeV are shown.

A modular 3D printed isothermal heat flow calorimeter for reaction calorimetry in continuous flow

Abstract: Utilization of highly reactive compounds in novel flow syntheses requires new tools for process development. This work presents such a tool in the form of a modular calorimeter designed for direct heat flux measurements in continuous flow applications. The calorimeter consists mainly of 3D printed parts, which can be adapted and reassembled easily to meet user-defined applications. By utilizing selective laser melting (SLM) of stainless steel and digital light processing (DLP) of a UV curable resin, a device is produced to meet the requirements of handling highly reactive organic compounds. Calorimeter segments are temperature-regulated independently of each other by a microcontroller, allowing isothermal operation conditions. Direct heat flux measurements are possible in the device through Seebeck elements which are calibrated internally at prevailing process conditions with the aid of heating foils. Functionality of the designed calorimeter is shown by good agreement of conducted heat flux measurements with literature.

Calorimeter for real-time dosimetry of pulsed ultra-high dose rate electron beams

Abstract: An aluminium calorimeter was investigated as a possible real-time dosimeter for electron beams with ultra-high dose per pulse (DPP) as clinical applied at FLASH radiation therapy (1.5 Gy/pulse). Ion chambers, the most widely used active dosimeter type in conventional external beam radiation therapy, suffer very large ion recombination losses at these conditions. Passive dosimeters, as e.g. alanine, are independent of dose rate but do not provide real-time readout. In this work it is shown that the response of alanine is independent of the DPP in the investigated ultra-high DPP range (up to 2.3 Gy/pulse). Alanine dose measurements were then used to determine the ion recombination correction for an Advanced Markus parallel-plate ion chamber at ultra-high DPP. Ion collection losses larger than 50 % were observed. Therefore, ion chambers are not considered suitable for accurate dosimetry in FLASH radiation therapy. As alternative an aluminium open-to-atmosphere calorimeter, operated in quasi-adiabatic mode was investigated at ultra-high DPP electron radiation. The beam pulse charge, and thus the DPP, was varied to evaluate the linearity of the calorimeter response in the DPP range between 0.3 and 1.8 Gy/pulse. On average, the standard deviation of the calorimeter response was 0.1 %. The response was proportional to the DPP in the investigated range. The average deviation of

A new exploration of the fire behaviors of large format lithium ion battery

Abstract: In this paper, the fire behaviors of 60 Ah LiFePO4/graphite batteries with no safety valve are evaluated using an in situ calorimeter. The batteries experience a stable combustion stage with a small-scale flame rather than immediate jet fire after ignition and the special combustion process is analyzed and discussed in detail. It takes 201 s from ignition to thermal runaway for fully charged battery under an incident heat flux of 11.1 kW m−2. Such a time interval is beneficial for a possible early warning of the battery thermal runaway. Several characteristic parameters, including the ignition time, surface temperature, mass loss, heat release rate (HRR), and flame size are systematically determined. The peak HRR can be as high as 82.3 kW and the maximum average flame height for batteries under an incident heat flux of 11.1 kW m−2 reaches 634.6 mm. The influence of different state of charge (SOC) and incident heat flux are also investigated. The results show that the fully charged batteries exposed to high external heat flux are more vulnerable to have thermal runaway.

Evolution of Specific Heat Capacity with Temperature for Typical Supports Used for Heterogeneous Catalysts

Abstract: Heterogeneous catalysts are widely used in the chemical industry. Compared with homogeneous catalysts, they can be easily separated from the reaction mixture. To design and optimize an efficient and safe chemical process one needs to calculate the energy balance, implying the need for knowledge of the catalyst’s specific heat capacity. Such values are typically not reported in the literature, especially not the temperature dependence. To fill this gap in knowledge, the specific heat capacities of commonly utilized heterogeneous catalytic supports were measured at different temperatures in a Tian–Calvet calorimeter. The following materials were tested: activated carbon, aluminum oxide, amberlite IR120 (H-form), H-Beta-25, H-Beta-38, H-Y-60, H-ZSM-5-23, H-ZSM-5-280, silicon dioxide, titanium dioxide, and zeolite 13X. Polynomial expressions were successfully fitted to the experimental data.

Compact phonon-scintillation detection system for rare event searches at low temperatures

Abstract: We have developed a compact cryogenic measurement system to investigate the phonon and scintillation properties of various scintillating crystals. This system employs a 1 × 1 × 1 cm 3 crystal for the simultaneous detection of heat (phonon) and light (scintillation) signals based on metallic magnetic calorimeter (MMC) readouts at milliKelvin temperatures. Three molybdate crystals of CaMoO 4 , Na 2 Mo 2 O 7 , and Li 2 MoO 4 were tested in the detector system. This work surveys scintillating crystals as target materials for neutrinoless double beta ( 0 ν β β ) decay of 100 Mo. All the measurements are successful in simultaneously detecting heat and light signals from the crystals. The measurements also results in clear particle identification using the pulse shapes and the relative amplitude ratios of the heat and light signals. We report the performance of the detector system through the amplitudes and time constants of the signals and the particle identification discrimination powers with discussion on 0 ν β β applications.

Development of a fast-response diamond calorimeter heat transfer gauge

Abstract: A robust fast-response calorimeter heat transfer gauge called the Diamond Heat Transfer Gauge has been developed for use in transient hypersonic ground test facilities. Gauges have been produced us...

Thermal hazardous evaluation of autocatalytic reaction of cumene hydroperoxide alone and mixed with products under isothermal and non-isothermal conditions

Abstract: Severe fire and explosions are frequent phenomena during handling of organic peroxides that are promoted supremely by conditions such as chemical impurities and thermal instability. As an initiator in the polymerization process, cumene hydroperoxide (CHP) has wide usage in the chemical process industry. This violently reactive chemical is studied here experimentally using differential scanning calorimeter (DSC), an isothermal mode of operation that can access the thermal hazards in the decomposition of CHP alone and later mixed with products following an autocatalytic reaction scheme. Importantly, DSC-evaluated thermokinetic parameters such as reaction enthalpy (ΔHd), time to maximum rate (TMRiso), and maximum heat flow (Qmax) were estimated to ascertain the degree of thermal hazard under various transportation and storage temperatures. The Heat-Wait-Search mode of accelerating rate calorimeter has been used to investigate decomposition kinetics parameters data under an adiabatic condition. Data such as initial exothermic temperature (T0), self-heating rate (dT/dt), pressure rise rate (dP/dt) and pressure–temperature profiles help to gauge the runaway reaction hazard of CHP alone and then mixed with its products to support the autocatalytic model of exothermic decomposition. The curve fitting data indicated that activation energy had reduced from 245.4 to 236.7 and 242.3 kJ mol−1, when CHP was mixed with acetone or dicumyl peroxide, respectively. The decrease in activation energy for autocatalytic material thermal decomposition reaction is depicted here with various experimental findings and mathematical analysis.

Polysiloxane-based scintillators for shashlik calorimeters

Abstract: We present the first application of polysiloxane-based scintillators as active medium in a shashlik sampling calorimeter. These results were obtained from a testbeam campaign of a ∼ 6 × 6 × 45 cm 3 (13 X 0 depth) prototype. A Wavelength Shifting fiber array of 36 elements runs perpendicularly to the stack of iron (15 mm) and polysiloxane scintillator (15 mm) tiles with a density of about one over cm 2 . Unlike shashlik calorimeters based on plastic organic scintillators, here fibers are optically matched with the scintillator without any intermediate air gap. The prototype features a compact light readout based on Silicon Photo-Multipliers embedded in the bulk of the detector. The detector was tested with electrons, pions and muons with energies ranging from 1 to 7 GeV at the CERN-PS. This solution offers a highly radiation hard detector to instrument the decay region of a neutrino beam, providing an event-by-event measurement of high-angle decay products associated with neutrino production (ENUBET, Enhanced NeUtrino BEams from kaon Tagging, ERC project). The results in terms of light yield, uniformity and energy resolution, are compared to a similar calorimeter built with ordinary plastic scintillators.

Measurements of pρTx and specific heat capacity cv for (R290 + R1243zf) binary mixtures at temperatures from (292 to 350) K and pressures up to 11 MPa

Abstract: In this paper, isochoric pρTx and specific heat capacity (cv) for (R290 + R1243zf) binary mixtures were measured using an adiabatic batch calorimeter with intermittent heating. A total of 57 pρTx data points over temperatures from (292 to 350) K and 82 isochoric specific heat capacity data points over temperatures from (299 to 350) K were obtained for liquid with mole fractions of R290 at (0.788, 0.606, 0.435 and 0.170). The standard uncertainties were estimated to be 12 mK for temperature, 5 kPa for pressure, 0.30% for density and 0.96% for isochoric specific heat capacity. The experimental density and heat capacity data agree well with the Helmholtz equation of state (EOS) developed by Bell and Lemmon (2016), and the average absolute relative deviation (AARD) are 0.27% and 1.01%, respectively. Comparisons of the present cv data with values calculated by the generalized equation developed by Zhong et al. (2019a) was carried out as well, and the results show good agreements with deviations varying from −3.00% to 3.16% and the average absolute relative deviation (AARD) of 0.91%.

Characterisation and performance of the PADME electromagnetic calorimeter

Abstract: The PADME experiment at the LNF Beam Test Facility searches for dark photons produced in the annihilation of positrons with the electrons of a fix target. The strategy is to look for the reaction $e^{+}+e^{-}\rightarrow \gamma+A'$, where $A'$ is the dark photon, which cannot be observed directly or via its decay products. The electromagnetic calorimeter plays a key role in the experiment by measuring the energy and position of the final-state $\gamma$. The missing four-momentum carried away by the $A'$ can be evaluated from this information and the particle mass inferred. This paper presents the design, construction, and calibration of the PADME's electromagnetic calorimeter. The results achieved in terms of equalisation, detection efficiency and energy resolution during the first phase of the experiment demonstrate the effectiveness of the various tools used to improve the calorimeter performance with respect to earlier prototypes.

High-resolution Calorimetry in Pulsed Magnetic Fields

Abstract: We have developed a new calorimeter for measuring thermodynamic properties in pulsed magnetic fields. An instrumental design is described along with the construction details including the sensitivity of a RuO2 thermometer. The operation of the calorimeter is demonstrated by measuring heat capacity of three samples, pure Germanium, CeCu2Ge2, and $\kappa$-(BEDT-TTF)2Cu[N(CN)2]Br, in pulsed fields up to 43.5 T. We have found that realization of field-stability is a key for measuring high-resolution heat capacity under pulsed fields. We have also tested the performance of the calorimeter by employing two measurement techniques; the quasi-adiabatic and dual-slope methods. We demonstrate that the calorimeter developed in this study is capable of performing high-resolution calorimetry in pulsed magnetic fields, which opens new opportunities for high-field thermodynamic studies.

New forward hadron calorimeter and hodoscope for the BM@N heavy ions experiment

Abstract: New forward hadron calorimeter with transverse and longitudinal segmentation has been developed and constructed for the upgraded fixed target BM@N experiment at JINR, Dubna. The main purpose of this calorimeter is to provide event-by-event centrality and reaction plane orientation measurements in nucleus-nucleus collisions. The design of the hadron calorimeter composed of sampling lead/scintillator modules with a beam hole in the center is discussed. The light collection from longitudinal sections in modules is provided by Wave Length Shifting (WLS) fibers embedded in scintillator plates. Micro-pixel photodetectors (Hamamatsu MPPCs) are used for light detection from each longitudinal section of modules. The measured light yield is about 50 photoelectrons per section for MIPs. Sampling ADCs are used for signal readout in the calorimeter. The performance of the FHCAL is discussed. For centrality measurement additional forward quartz hodoscope is developed to measure charge of fragments in the FHCAL beam hole. The method of collision centrality determination is discussed.

The ENUBET positron tagger prototype: Construction and testbeam performance

Abstract: A prototype for the instrumented decay tunnel of ENUBET was tested in 2018 at the CERN East Area facility with charged particles up to 5 GeV. This detector is a longitudinal sampling calorimeter with lateral scintillation light readout. The calorimeter was equipped by an additional "$t_0$-layer" for timing and photon discrimination. The performance of this detector in terms of electron energy resolution, linearity, response to muons and hadron showers are presented in this paper and compared with simulation. The $t_0$-layer was studied both in standalone mode using pion charge exchange and in combined mode with the calorimeter to assess the light yield and the 1 mip/2 mip separation capability. We demonstrate that this system fulfills the requirements for neutrino physics applications and discuss performance and additional improvements.

Reconstruction of signal amplitudes in the CMS electromagnetic calorimeter in the presence of overlapping proton-proton interactions

Abstract: A template fitting technique for reconstructing the amplitude of signals produced by the lead tungstate crystals of the CMS electromagnetic calorimeter is described. This novel approach is designed to suppress the contribution to the signal of the increased number of out-of-time interactions per beam crossing following the reduction of the accelerator bunch spacing from 50 to 25 ns at the start of Run 2 of the LHC. Execution of the algorithm is sufficiently fast for it to be employed in the CMS high-level trigger. It is also used in the offline event reconstruction. Results obtained from simulations and from Run 2 collision data (2015–2018) demonstrate a substantial improvement in the energy resolution of the calorimeter over a range of energies extending from a few GeV to several tens of GeV.