Search Results (9)

Calorimetry at the High Luminosity LHC (HL-LHC) faces many challenges, particularly in the forward direction, such as radiation tolerance and large in-time event pileup. To meet these challenges, the CMS Collaboration is preparing to replace its current endcap calorimeters from the HL-LHC era with a high-granularity calorimeter (HGCAL), featuring an unprecedented transverse and longitudinal segmentation, for both the electromagnetic and hadronic compartments, with 5D information (space–time–energy) read out. The proposed design uses silicon sensors for the electromagnetic section (with fluences above ${10}^{16} {\mathrm{n}}_{eq}{\mathrm{/cm}}^2$) and high-irradiation regions (with fluences above ${10}^{14} {\mathrm{n}}_{eq}{\mathrm{/cm}}^2$) of the hadronic section, while in the low-irradiation regions of the hadronic section, plastic scintillator tiles equipped with on-tile silicon photomultipliers (SiPMs) are used. Full HGCAL will have approximately 6 million silicon sensor channels and about 280 thousand channels of scintillator tiles. This will allow for particle-flow-type calorimetry, where the fine structure of showers can be measured and used to enhance particle identification, energy resolution and pileup rejection. In this overview we present the ideas behind HGCAL, the current status of the project, results of the beam tests and the challenges that lie ahead. Full article

Noble liquid calorimeters have been successfully used in particle physics experiments for decades. The project presented in this article is that of a new noble liquid calorimeter concept, where a novel design allows us to fulfil the stringent requirements on calorimetry of the physics programme of the electron-positron Future Circular Collider at CERN. High granularity is achieved through the design of specific readout electrodes and high-density cryostat feedthroughs. Excellent performance can be reached through new very light cryostat design and low electronics noise. Preliminary promising performance is achieved in simulations, and ideas for further R&D opportunities are discussed. Full article

The SiD detector concept capitalizes on high granularity in its tracker and calorimeter to achieve the momentum resolution and particle flow calorimetry physics goals in a compact design. The collaboration has had a long interest in the potential for improved granularity in both the tracker and ECal with an application of monolithic active pixel sensors (MAPS) and a study of MAPS in the SiD ECal was described in the ILC TDR. Work is progressing on the MAPS application in an upgraded SiD design with a prototyping design effort for a common SiD tracker/ECal design based on stitched reticules to achieve 10 × 10 cm² sensors with 25 × 100 micron² pixels. Application of large area MAPS in these systems would limit delicate and expensive bump-bonding, provide possibilities for better timing, and should be significantly cheaper than the TDR concept due to being a more conventional CMOS foundry process. The small pixels significantly improve shower separation. Recent simulation studies confirm previous performance projections, indicating electromagnetic energy resolution based on digital hit cluster counting provides better performance than the SiD TDR analog design based on 13 mm² pixels. Furthermore, the two shower separation is excellent down to the millimeter scale. Geant4 simulation results demonstrate these expectations. Full article

A novel high-granularity, dual-readout calorimetric technique (ADRIANO2) is under development as part of the research program of T1604 Collaboration. (Talk Presented at the 19th International Conference on Calorimetry in Particle Physics (CALOR 2022), University of Sussex, Sussex, UK, 16–20 May 2022). The building block of such a calorimeter consists of a pair of optically isolated, small size tiles made of scintillating plastic and lead glass. The prompt Čerenkov light from the glass can be exploited to perform high resolution timing measurements, while the high granularity provides good resolution of the spatial components of the shower. Dual-readout compensation and particle flow techniques can be applied simultaneously to the scintillation and to the Čerenkov section, providing excellent energy resolution as well as PID particle identification. These characteristics make ADRIANO2 a 6-D detector, suited for High Energy as well as High Intensity experiments. A report on the status of the ADRIANO2 project, preliminary measurements of light yield, and current and future R&D plans by T1604 Collaboration are discussed. Full article

Precision measurements of Z, W, and H decays at the next generation of circular lepton colliders will require excellent energy resolution for both electromagnetic and hadronic showers. The resolution is limited by event-to-event fluctuations in the shower development, especially in the hadronic system. Compensating for this effect can greatly improve the achievable energy resolution. Furthermore, the resolution can benefit greatly from the use of particle-flow algorithms, which requires the calorimeters to have a high granularity. The approach of dual-readout calorimetry has emerged as a candidate to fulfil both of these requirements by allowing to reconstruct the fluctuations in the shower development event-by-event and offering a high transverse granularity. An important benchmark of such a calorimeter is the electromagnetic energy resolution; a prototype of the IDEA calorimeter has been built for use in testbeams. In parallel, a simulation of this prototype has been developed in Geant4 for a testbeam environment. Here, we outline how this simulation was used to study the electromagnetic energy resolution and conclude that a resolution of $14\%/\sqrt{E}$ is achievable. Full article

We report a greater than factor of two improvement in the hadronic energy resolution of a simulated Cherenkov calorimeter by estimating the energy with machine learning over traditional techniques. The prompt signal formation and energy threshold properties of Cherenkov radiation provide identifiable features that machine learning techniques can exploit to produce a superior model for energy reconstruction. We simulated a quartz-fiber calorimeter via the GEANT4 framework to study the reconstruction techniques in single events. We compared the machine learning-based reconstruction performance to the traditional simple sum of signal and dual-readout techniques that use both Cherenkov and scintillation signals. We describe why this game-changing approach to Cherenkov hadron calorimetry excels and our plans for a dedicated beam test to validate these findings with a fast, radiation-hard hadron calorimeter prototype. Full article

The Liquid Argon Calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region $\left|\mathrm{\eta }\right|<3.2$, and for hadronic and forward calorimetry in the region from $\left|\mathrm{\eta }\right|=1.5$ to $\left|\mathrm{\eta }\right|=4.9$. They also provide inputs to the first level of the ATLAS trigger. After a successful period of data taking during the LHC Run 2 between 2015 and 2018, the ATLAS detector entered into a long period of shutdown. In 2022, the LHC will restart and the Run 3 period should see an increase of luminosity and pile-up of up to 80 interactions per bunch crossing. To cope with these harsher conditions, a new trigger readout path has been installed during the long shutdown. This new path should significantly improve the triggering performance on electromagnetic objects. This will be achieved by increasing the granularity of the objects available at trigger level by up to a factor of ten. The installation of this new trigger readout chain also required the update of the legacy system. More than 1500 boards of the precision readout have been extracted from the ATLAS pit, refurbished and re-installed. The legacy analog trigger readout, which will remain during the LHC Run 3 as a backup of the new digital trigger system, has also been updated. For the new system, 124 new on-detector boards have been added. Those boards that are operating in a radiative environment are digitizing the calorimeter trigger signals at 40 MHz. The digital signal is sent to the off-detector system and processed online to provide the measured energy value for each unit of readout. In total up to 31 Tbps are analyzed by the processing system and more than 62Tbps are generated for downstream reconstruction. To minimize the triggering latency the processing system had to be installed underground. The limited available space imposed a very compact hardware structure. To achieve a compact system, large FPGAs with high throughput have been mounted on ATCA mezzanines cards. In total, no more than three ATCA shelves are used to process the signal from approximately 34,000 channels. Given that modern technologies have been used compared to the previous system, all the monitoring and control infrastructure is being adapted and commissioned as well. This contribution presents the challenges of the installation, the commissioning and the milestones still to be completed towards the full operation of both the legacy and the new readout paths for the LHC Run 3. Full article

Based on the particle-flow paradigm, a new hadronic calorimeter (HCAL) with scintillating glass tiles is proposed to address major challenges from precision measurements of jets at the future lepton colliders, such as the Circular Electron Positron Collider (CEPC). Tiles of high-density scintillating glass, with a high-energy sampling fraction, can significantly improve the hadronic energy resolution in the low-energy region (typically below 10 GeV for major jet components at Higgs factories). The hadronic energy resolution of single hadrons and the effects of key parameters of scintillating glass have been evaluated in the Geant4 full simulation, followed by the physics benchmark studies on the Higgs boson with jets in the final state. R&D efforts of scintillating glass materials are ongoing within a dedicated collaboration since 2021 with the aim to achieve a high light yield, a high density, and a low cost. Measurements have been performed for the first batches of scintillating glass samples including the light yield, emission and scintillation spectra, scintillation decay times, and cosmic responses. An optical simulation model of a single scintillating glass tile has been established to provide guidance in the development of scintillating glass. Highlights of the expected detector performance and the latest scintillating glass developments are presented in this contribution. Full article

Polylactic acid (PLA) has made inroads in the commercial market segment with many unique characteristics. To list a few, such as tenacity, low flame rate, moisture regain percentage, loss of ignition percentage, combustion heat, UV resistance, elastic recovery, and higher melting point, make PLA a predominant material in the commercial market. This study is an attempt to test the feasibility of PLA’s mechanical property and strength aspects with cement mix. An article published on biodegradability aspects backed up by the essential preliminary strength and physical test results is discussed in detail in this manuscript. The work focuses on the multi-scale study along with mechanical properties and strengths to evaluate the elemental characteristics. Thermo gravimetric analysis revealed that PLA would hold inclusion into construction applications either in granular form or filament. Differential Scanning Calorimetry (DSC) found that PLA in filament form is the best inclusion material for construction applications. However, fiber’s tenacity has to be checked, as currently available filaments in the market do not have high tenacity value. From EDX(Energy-dispersive X-ray Spectroscopy) reports, 30% inclusion of PLA as a replacement for fine aggregate has constituent members as Calcium carbonate(CaCO₃), Silica(SiO₂), and Wollastonite (CaK) resulted in the best composition among the rest. FESEM images revealed that proper gradation in size, PLA granular form’s rough surface, or filament form would enhance the mechanical/physical behavior or even PLA’s chemical behavior. Full article