Yazar "Tiras E." seçeneğine göre listele

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    Commissioning of CMS Forward Hadron calorimeters with upgraded multi-anode PMTs and ?TCA readout
    (Proceedings of Science (PoS), 2016) Tiras E.; Bilki B.; Onel Y.
    The high flux of charged particles interacting with the CMS Forward Hadron Calorimeter PMT windows introduced a significant background for the trigger and offline data analysis. During Long Shutdown 1, all of the original PMTs were replaced with multi-anode, thin window photomultiplier tubes. At the same time, the back-end electronic readout system was upgraded to ?TCA readout. The experience with commissioning and calibration of the Forward Hadron Calorimeter is described as well as the ?TCA system. The upgrade was successful and provided quality data for Run 2 data-analysis at 13 TeV. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).
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    Development of radiation hard scintillators
    (Proceedings of Science (PoS), 2016) Tiras E.; Wetzel J.; Bilki B.; Winn D.; Onel Y.
    Modern high-energy physics experiments are in ever increasing need for radiation hard scintillators and detectors. In this regard, we have studied various radiation-hard scintillating materials such as Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), our prototype material Scintillator X (SX) and Eljen (EJ). Scintillation and transmission properties of these scintillators are studied using stimulated emission from a 334 nm wavelength UV laser with PMT before and after certain amount of radiation exposure. Recovery from radiation damage is studied over time. While the primary goal of this study is geared for LHC detector upgrades, these new technologies could easily be used for future experiments such as the FCC and ILC. Here we discuss the physics motivation, recent developments and laboratory measurements of these materials. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).
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    Measuring the Scintillation Decay Constant of Pen and PET with 120 GeV Proton Beam Excitation
    (Institute of Electrical and Electronics Engineers Inc., 2020) Wetzel J.W.; Tiras E.; Bilki B.; Koseyan O.; Bostan N.; Onel Y.
    We report the scintillation decay constants of polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) determined by excitation of the plastic substrate with an accelerated beam of protons and resulting light yield measured as a function of time with a photomultiplier attached to an oscilloscope. The decay constant of PEN was found to be 35 ns and PET 7 ns. © 2020 IEEE
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    Performance Measurements of Optical Scintillating Fibers After Repeated Exposure to Radiation
    (Institute of Electrical and Electronics Engineers Inc., 2020) Wetzel J.W.; Tiras E.; Koseyan O.; Bostan N.; Bilki B.; Winn D.R.; Onel Y.
    We report the preliminary results from repeated irradiations of optical scintillating fibers exposed to gamma radiation. Optical fibers degrade in radiation fields, but exhibit some recovery once removed. Study of repeated irradiations are difficult to find in the literature. We find that a UV-blue optical wavelength shifting fiber exhibits permanent degradation, the recovery is incomplete, and an interesting two step damage process that appears to affect which wavelengths are darkened at different rates. © 2020 IEEE
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    Radiation Damage and Recovery Mechanisms of Various Scintillators and Fibers
    (Institute of Electrical and Electronics Engineers Inc., 2021) Wetzel J.W.; Bilki B.; Bostan N.; Koseyan O.K.; Onel Y.; Tiras E.; Winn D.
    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. © 2021 IEEE.
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    Results from in Situ Monitoring of Radiation Damage of Scintillation Fibers
    (Institute of Electrical and Electronics Engineers Inc., 2020) Wetzel J.W.; Tiras E.; Koseyan O.; Bostan N.; Bilki B.; Winn D.R.; Onel Y.
    We report preliminary results from in situ monitoring of an optical scintillating fiber while being exposed to a cesium-173 gamma radiatior. We measured the degradation of fiber transmittance across the visible spectrum as a function of time. We observed that the region below 500 nm was degraded quickly and thoroughly while wavelengths above 500 nm lost clarity more slowly. © 2020 IEEE
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    Secondary Emission Calorimetry
    (Institute of Electrical and Electronics Engineers Inc., 2022) Bilki B.; Dilsiz K.; Ogul H.; Onel Y.; Southwick D.; Tiras E.; Wetzel J.
    In high-radiation environments, electromagnetic calorimetry is particularly challenging. To address this, a feasible approach involves constructing a sampling calorimeter that employs radiation-hard active media, albeit at the expense of high energy resolution. In response, we developed an innovative technique, secondary emission calorimetry, which offers radiation resistance, rapid response, robustness, and cost-effectiveness. Our efforts involve the creation of prototype secondary emission sensors, subjected to comprehensive testing within test beams. In the secondary emission detector module, incident charged hadrons or electromagnetic shower particles trigger the generation of secondary emission electrons from a cathode. These generated electrons are subsequently amplified in a manner similar to the process within photomultiplier tubes. This report provides an insight into the principles underlying secondary emission calorimetry, presents findings from beam tests, and outlines Monte Carlo simulations that project towards the potential application of large-scale secondary emission electromagnetic calorimeters. © 2022 IEEE.