MRI Consortium: Development of a Forward Calorimetry Upgrade for the STAR Detector

MRI 联盟：开发 STAR 探测器的正向量热升级

• 批准号: 1920077
• 负责人: Scott Wissink
• 金额: $ 195万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1920077&HistoricalAwards=false
• 关键词: MRI; Consortium; Development; Forward; Calorimetry

Quantum Chromodynamics, or QCD, is considered a cornerstone of modern physics. As the fundamental theory of the nuclear force, it describes strongly interacting matter in terms of point-like quarks bound together via exchange of massless particles called gluons. Yet despite its remarkable success in explaining measurements carried out at the highest energies, a detailed understanding of low-energy phenomena, such as the internal structure of the protons and neutrons that make up 99% of the visible mass of the universes, remains elusive theoretically and must be gained through experiment. Over the last few decades, much progress has been made in this area, but not for the very low or very high energy constituents within the proton. This project will upgrade the STAR detector in order to make possible the study of proton-proton collision products at far-forward angles, a kinematic regime dominated by the scattering of high-momentum quarks on low-momentum gluons. This study will provide a unique opportunity to explore how the quarks, gluons, and their spins are distributed in space and momentum. Using the same techniques in proton-nucleus collisions will allow for a better understanding of how properties of protons and neutrons are modified in the nuclear environment. That in turn will improve the understanding of nucleus-nucleus collisions.The STAR forward upgrade is designed to explore QCD physics in the very high and low regions of partonic momentum fraction, a kinematic regime that has thus far remained inaccessible at RHIC. It will provide superior detection and reconstruction capabilities for neutral pions, photons, electrons, jets, and leading hadrons over the pseudo-rapidity range 2.5-4. To reduce costs and risk, much of the detector package will consist of previously used components. The electromagnetic calorimeter will use refurbished sampling Pb-scintillator blocks from PHENIX. The hadronic calorimeter will be a sandwich iron-scintillator plate sampling type, designed and prototyped with separate R&D funds. Both calorimeters will share the same cost-effective readout electronics, and will use SiPMs as photo-sensors, thereby allowing them to operate without shielding in high magnetic fields and high radiation environments, as will be encountered in this location. By design, the system is scalable and reconfigurable: the EMCal blocks are simply stacked vertically, while HCal "slabs" will be assembled in place. Integration into STAR will require only minimal modification of existing infrastructure. Based on detailed GEANT simulations, the Forward Calorimetry System (FCS) will have very good electromagnetic (10% / sqrt(E) + 3%) and hadronic (~50% / sqrt(E) + 10%) energy resolution.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

量子色动力学（QCD）被认为是现代物理学的基石。作为核力的基本理论，它描述了强相互作用的物质，通过交换称为胶子的无质量粒子，将点状夸克束缚在一起。然而，尽管它在解释最高能量下进行的测量方面取得了显着的成功，但对低能现象的详细理解，例如构成宇宙可见质量99%的质子和中子的内部结构，在理论上仍然难以捉摸，必须通过实验来获得。在过去的几十年里，在这一领域取得了很大的进展，但不是质子中的非常低或非常高的能量成分。该项目将升级星星探测器，以便能够在远前角研究质子-质子碰撞产物，这是一种由高动量夸克在低动量胶子上的散射主导的运动学状态。这项研究将提供一个独特的机会来探索夸克、胶子及其自旋如何在空间和动量中分布。在质子-核碰撞中使用相同的技术将允许更好地理解质子和中子的性质如何在核环境中改变。星星的前向升级旨在探索部分子动量分数非常高和非常低的区域中的QCD物理，这是一个迄今为止在RHIC中仍然无法实现的运动学区域。它将为赝快度范围2.5-4的中性π介子、光子、电子、喷流和主导强子提供上级探测和重建能力。为了降低成本和风险，探测器包的大部分将由以前使用的组件组成。电磁量热计将使用PHENIX公司的翻新取样铅闪烁体块。强子量能器将是一个三明治铁闪烁体板采样类型，设计和原型与单独的研发基金。这两种量热计将共享相同的具有成本效益的读出电子设备，并将使用SiPM作为光传感器，从而使它们能够在高磁场和高辐射环境中无屏蔽地工作，正如在该位置将遇到的那样。通过设计，该系统是可扩展和可重新配置的：EMCal块只是垂直堆叠，而HCal“板”将在适当的位置组装。与星星的集成只需要对现有基础设施进行最小的修改。基于详细的GEANT模拟，前向量热系统（FCS）将具有非常好的电磁（10% / sqrt（E）+ 3%）和强子（~50% / sqrt（E）+ 10%）能量分辨率。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。