Louis Roux;Loris Martinazzoli;Marco PIzzichemi;Christophe Dujardin;Etiennette Auffray
{"title":"Influence of Crystal Fiber Inhomogeneity on the Energy Resolution of a Sampling Electromagnetic Calorimeter","authors":"Louis Roux;Loris Martinazzoli;Marco PIzzichemi;Christophe Dujardin;Etiennette Auffray","doi":"10.1109/TNS.2025.3559721","DOIUrl":null,"url":null,"abstract":"Sampling electromagnetic calorimeters (ECALs) are widely used in high-energy physics (HEP) experiments, thanks to their ability to efficiently measure electromagnetic particles’ energy over a broad dynamic range while maintaining good energy resolution. These detectors alternate passive layers made of dense absorber materials, with active layers, such as scintillators. Scintillating materials, such as inorganic garnets, are promising candidates for high-luminosity environments such as the Large Hadron Collider (LHC) due to their high radiation hardness, ensuring longer operational lifetimes without compromising performance. However, fluctuations in light yield (LY) can lead to a degradation in energy resolution (<inline-formula> <tex-math>$E_{R}$ </tex-math></inline-formula>). One concept of sampling calorimeter is the so-called spaghetti calorimeter (SpaCaL); it relies on optimal scintillating fiber placement inserted in the heavy absorber. Hence, addressing possible LY variations is critical to guarantee that the detector meets the stringent requirements of future high-luminosity runs at the LHC. To maintain optimal ECAL performance, providing feedback to scintillator producers on the acceptable limits of LY variation is essential. For this purpose, a tungsten for the absorber and GAGG for the scintillating material of the sampling electromagnetic calorimeter (W-GAGG) SpaCal was modeled using Monte Carlo (MC) methods. Electrons with energies ranging from 1 to 100 GeV were simulated through the SpaCal to study <inline-formula> <tex-math>$E_{R}$ </tex-math></inline-formula>. We introduced artificial longitudinal variations of LY along the GAGG fibers with fixed values across a range of conditions to evaluate their impact on our modeled detector’s performance. Our results indicate that to preserve <inline-formula> <tex-math>$E_{R}$ </tex-math></inline-formula> and maintain an acceptable constant term <inline-formula> <tex-math>$c=1\\%$ </tex-math></inline-formula>, the longitudinal variation of LY should not exceed 2%/cm. In addition, we found the optimal fiber configuration to minimize performance degradation from LY fluctuations by testing different end orientations and placements relative to the reflector in both SpaCal sections.","PeriodicalId":13406,"journal":{"name":"IEEE Transactions on Nuclear Science","volume":"72 7","pages":"2076-2081"},"PeriodicalIF":1.9000,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10962144","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Transactions on Nuclear Science","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/10962144/","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Sampling electromagnetic calorimeters (ECALs) are widely used in high-energy physics (HEP) experiments, thanks to their ability to efficiently measure electromagnetic particles’ energy over a broad dynamic range while maintaining good energy resolution. These detectors alternate passive layers made of dense absorber materials, with active layers, such as scintillators. Scintillating materials, such as inorganic garnets, are promising candidates for high-luminosity environments such as the Large Hadron Collider (LHC) due to their high radiation hardness, ensuring longer operational lifetimes without compromising performance. However, fluctuations in light yield (LY) can lead to a degradation in energy resolution ($E_{R}$ ). One concept of sampling calorimeter is the so-called spaghetti calorimeter (SpaCaL); it relies on optimal scintillating fiber placement inserted in the heavy absorber. Hence, addressing possible LY variations is critical to guarantee that the detector meets the stringent requirements of future high-luminosity runs at the LHC. To maintain optimal ECAL performance, providing feedback to scintillator producers on the acceptable limits of LY variation is essential. For this purpose, a tungsten for the absorber and GAGG for the scintillating material of the sampling electromagnetic calorimeter (W-GAGG) SpaCal was modeled using Monte Carlo (MC) methods. Electrons with energies ranging from 1 to 100 GeV were simulated through the SpaCal to study $E_{R}$ . We introduced artificial longitudinal variations of LY along the GAGG fibers with fixed values across a range of conditions to evaluate their impact on our modeled detector’s performance. Our results indicate that to preserve $E_{R}$ and maintain an acceptable constant term $c=1\%$ , the longitudinal variation of LY should not exceed 2%/cm. In addition, we found the optimal fiber configuration to minimize performance degradation from LY fluctuations by testing different end orientations and placements relative to the reflector in both SpaCal sections.
期刊介绍:
The IEEE Transactions on Nuclear Science is a publication of the IEEE Nuclear and Plasma Sciences Society. It is viewed as the primary source of technical information in many of the areas it covers. As judged by JCR impact factor, TNS consistently ranks in the top five journals in the category of Nuclear Science & Technology. It has one of the higher immediacy indices, indicating that the information it publishes is viewed as timely, and has a relatively long citation half-life, indicating that the published information also is viewed as valuable for a number of years.
The IEEE Transactions on Nuclear Science is published bimonthly. Its scope includes all aspects of the theory and application of nuclear science and engineering. It focuses on instrumentation for the detection and measurement of ionizing radiation; particle accelerators and their controls; nuclear medicine and its application; effects of radiation on materials, components, and systems; reactor instrumentation and controls; and measurement of radiation in space.