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

该合同将为布鲁克海文国家实验室相对论重离子对撞机(RHIC)的事件平面探测器sPHENIX事件平面探测器(SEPD)的建造、安装和调试提供资金。在RHIC，原子核被加速到接近光速，然后相互碰撞，以形成一滴非常热的物质，以至于组成原子核的中子和质子的夸克和胶子不再受到限制。理解这种新的物质形式，称为夸克胶子等离子体(QGP)，可以更好地理解强大的核力和亚原子物质自我组织的机制。QGP在产生后迅速膨胀和冷却，其性质是通过测量探测器中产生的粒子来研究的。SEPD将允许通过在其他探测器未覆盖的区域测量精细分割的带电粒子来更好地表征每次碰撞，因此将提高多次测量的精度。了解RHIC上QGP的液滴有多小具有根本意义，只能通过SEPD提供的更高精度来确定。探测器的设计和建造将在大学一级进行，本科生和研究生将大力参与，对他们来说，这样的动手机会越来越少。来自代表性不足的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，他们在这方面的历史代表性一直很低。sPHENIX探测器目前正在建造中，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将是一种新的探测器，它将被集成到sPHENIX中，以提供RHIC喷注淬火各向异性的独特测量。该提议是设计、建造和安装SEPD，以便在2023年获取数据。SEPD包括两个子探测器，每个子探测器位于前角和后角区域中。每个子探测器包括12个方位扇区，每个扇区有31个段。每一段都是一块闪烁体，嵌入了一根光纤来提取光信号，然后通过硅光电倍增管(SiPM)读出信号。闪烁体将由数控机床加工，光纤组件由学生和博士后团队粘合在一起。电子读取链将主要使用已经为sPHENIX设计的电子产品，但SiPM的电路板和它们所需的放大电路将为该项目重新设计和组装。每个完成的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正确。完整的SEPD探测器将在布鲁克海文国家实验室组装和安装。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.