Abstract
We present the first beam test results with centimeter-scale AC-LGAD strip sensors, using
the Fermilab Test Beam Facility and sensors manufactured by the Brookhaven National
Laboratory. ...Sensors of this type are envisioned for applications that require large-area precision
4D tracking coverage with economical channel counts, including timing layers for the Electron Ion
Collider (EIC), and space-based particle experiments. A survey of sensor designs is presented,
with the aim of optimizing the electrode geometry for spatial resolution and timing
performance. Several design considerations are discussed towards maintaining desirable signal
characteristics with increasingly larger electrodes. The resolutions obtained with several
prototypes are presented, reaching simultaneous 18 μm and 32 ps resolutions from
strips of 1 cm length and 500 μm pitch. With only slight modifications, these
sensors would be ideal candidates for a 4D timing layer at the EIC.
As the intensity frontier in high energy physics increases, new materials, tools, and techniques must be developed in order to accommodate the prolonged exposure of detectors to high amounts of ...radiation. It has been observed recently that many of the active media of detectors could survive to much lower radiation doses than initially expected. In addition to the challenges introduced by extremely high doses of radiation, there is also a significant lack of in-situ radiation damage recovery systems. In recent studies, we investigated the radiation damage to common plastic scintillators such as polyethylene naphthalate, and polyethylene terephthalate, a custom made elastomer based plastic scintillator, various special glasses and scintillating fibers together with their recovery mechanisms. Here we report on the irradiation studies and the investigation of the recovery mechanisms under various conditions.
We study the light output, light collection efficiency and signal timing of a variety of organic scintillators that are being considered for the upgrade of the hadronic calorimeter of the CMS ...detector. The experimental data are collected at the H2 test-beam area at CERN, using a 150 GeV muon beam. In particular, we investigate the usage of over-doped and green-emitting plastic scintillators, two solutions that have not been extensively considered. We present a study of the energy distribution in plastic-scintillator tiles, the hit efficiency as a function of the hit position, and a study of the signal timing for blue and green scintillators.
The Phase I upgrade of the CMS Hadron Endcap Calorimeters consists of new photodetectors (Silicon Photomultipliers in place of Hybrid Photo-Diodes) and front-end electronics. The upgrade will ...eliminate the noise and the calibration drift of the Hybrid Photo-Diodes and enable the mitigation of the radiation damage of the scintillators and the wavelength shifting fibers with a larger spectral acceptance of the Silicon Photomultipliers. The upgrade also includes increased longitudinal segmentation of the calorimeter readout, which allows pile-up mitigation and recalibration due to depth-dependent radiation damage. As a realistic operational test, the responses of the Hadron Endcap Calorimeter wedges were calibrated with a 60Co radioactive source with upgrade electronics. The test successfully established the procedure for future source calibrations of the Hadron Endcap Calorimeters. Here we describe the instrumentation details and the operational experiences related to the sourcing test.
To address the challenges of providing high performance calorimetry in future hadron collider experiments under conditions of high luminosity and high radiation (FCChh environments), we are ...conducting R&D on advanced calorimetry techniques suitable for such operation, based on scintillation and wavelength-shifting technologies and photosensor (SiPM and SiPM-like) technology. In particular, we are focusing our attention on ultra-compact radiation hard EM calorimeters, based on modular structures (RADiCAL modules) consisting of alternating layers of very dense absorber and scintillating plates, read out via radiation hard wavelength shifting (WLS) solid fiber or capillary elements to photosensors positioned either proximately or remotely, depending upon their radiation tolerance. The RADiCAL modules provide the capability to measure simultaneously and with high precision the position, energy and timing of EM showers. This paper provides an overview of the instrumentation and photosensor R&D associated with the RADiCAL program.
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