MRI Consortium: Development of an Event Plane Detector for the sPHENIX Experiment at the Relativistic Heavy Ion Collider

该合同将资助布鲁克海文国家实验室的相对论重离子对撞机（RHIC）的sPHENIX事件平面探测器（sEPD）的建造、安装和调试。在RHIC中，原子核被加速到接近光速，然后相互碰撞，形成一个物质液滴，其温度如此之高，以至于组成原子核中子和质子的夸克和胶子不再受到限制。了解这种被称为夸克胶子等离子体（QGP）的新型物质，可以更好地理解强核力和亚原子物质自身组织的机制。QGP在产生后迅速膨胀和冷却，它的性质是通过测量探测器中产生的粒子来研究的。sEPD将通过在其他探测器未覆盖的区域内测量精细分割的带电粒子来更好地表征每次碰撞，从而提高多次测量的精度。了解QGP在RHIC中可以存在多小的液滴是至关重要的，并且只能使用sEPD授予的更高精度来确定。探测器的设计和建造将在大学层面进行，有本科生和研究生的强烈参与，对他们来说，这种动手的机会越来越少。来自代表性不足群体的学生将被招募，以增加他们对粒子和核物理探测器开发的参与，与整个物理学相比，他们在这些领域的代表性一直很低。sPHENIX探测器目前正在建设中，将于2023年在布鲁克海文国家实验室的相对论重离子对撞机上进行首次数据采集。sEPD将是一个新的探测器，将集成到sPHENIX中，在RHIC上提供独特的射流淬火各向异性测量。该建议是在2023年及时设计、建造和安装sEPD以获取数据。sEPD包括两个子探测器，分别位于前角和后角区域。每个子探测器包括12个方位扇区，每个扇区有31段。每一段都是一个闪烁体瓦，嵌入了一根光纤来提取光信号，然后通过硅光电倍增管（sipm）读出。闪烁体将由数控机床加工，光纤组件将由学生和博士后团队粘合。电子读出链将主要使用已经为sPHENIX设计的电子设备，但用于sipm的电路板及其所需的放大电路将为该项目新设计和组装。每个成品组件将使用放射性锶源进行测试，以确定测量效率并确保光纤的内部映射是正确的。完整的sEPD探测器将在布鲁克海文国家实验室组装和安装。该奖项反映了美国国家科学基金会的法定使命，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。

This award will fund the construction, installation, and commissioning of an Event Plane Detector called the sPHENIX Event Plane Detector (sEPD) at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. At RHIC, nuclei are accelerated to nearly the speed of light, and then collided in order to form a droplet of matter so hot that the quarks and gluons which comprise the neutrons and protons of the nuclei are no longer confined. Understanding this novel form of matter, called the Quark Gluon Plasma (QGP), allows a better understanding of the strong nuclear force and the mechanism by which sub-atomic matter organizes itself. The QGP rapidly expands and cools after its creation, and its properties are investigated through measurements of the resulting particles in the detectors. The sEPD will allow each collision to be better characterized by measuring charged particles with fine segmentation in a region not covered by other detectors, and will therefore improve the precision of multiple measurements. Understanding how small a droplet of QGP at RHIC can exist is of fundamental interest and can only be determined using the increased precision granted by the sEPD. The design and construction of the detector will be carried out at the university level, with strong involvement of undergraduate and graduate students, for whom such hands-on opportunities are increasingly rare. Students from underrepresented groups will be recruited in order to increase their participation in particle and nuclear physics detector development, where they have been historically poorly represented compared to physics as a whole.The sPHENIX detector is currently under construction and will be commissioned for first data taking in 2023 at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The sEPD will be a new detector that will be integrated into sPHENIX to deliver unique measurements of jet quenching anisotropy at RHIC. The proposal is to design, build, and install the sEPD in time for data taking in 2023. The sEPD comprises two sub-detectors, one in each of the forward and backward angle regions. Each sub-detector comprises 12 azimuthal sectors, each with 31 segments. Each segment is a scintillator tile with an optical fiber embedded to extract the light signal, which is then read out via silicon photomultipliers (SiPMs). The scintillator will be milled by CNC machines, with the optical fiber assemblies glued in by teams of students and post-docs. The electronics read-out chain will largely use electronics already designed for sPHENIX, but the boards for the SiPMs and the amplification circuit they require will be newly designed and assembled for the project. Each finished assembly will be tested using a radioactive strontium source in order to determine the measurement efficiency and to ensure that the internal mapping of the optical fibers is correct. The full sEPD detector will be assembled and installed at Brookhaven National Laboratory.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.