MRI: Construction of One Layer of a Highly Efficient Neutron Detector to Study Neutron-Rich Rare Isotopes at the NSCL

由密歇根州立大学和佛罗里达州立大学组成的联盟提议建造一个高效、大面积的中子探测器，用于探测高能中子，用于国家超导回旋加速器实验室（NSCL）的快速稀有同位素实验。该联盟由波尔州立大学、中密歇根大学、明尼苏达州穆尔黑德的康考迪亚学院加入。美国霍普学院、印第安纳大学南本德分校、米利金大学、西密歇根大学和韦斯特蒙特学院，每一所大学都将组装和测试探测器的一个完整层。该探测器由144个水平的塑料闪烁体块组成，分布在9层，每层16个探测器，覆盖面积为2.0米宽，1.6米高。该探测器具有位置敏感和多命中能力。无源铁转换器的加入提高了对能量在100 MeV以上的中子的探测效率，平均效率高达70%。高探测效率将允许研究只能用小强度产生的非常富中子的核。该探测器将与新型扫磁器及其独立模式的焦平面探测器以及扫磁器和S800磁谱仪的组合一起使用。因此，它对耦合回旋加速器设施的实验程序是必不可少的。由于其模块化设计，探测器可以优化到更高的光束能量，只需进行微小的修改。它可能是第一个用于稀有同位素快速碎片束的探测器。

The consortium between Michigan State University and Florida StateUniversity proposes the construction of a highly efficient,large-area neutron detector for the detection of high-energyneutrons to be used in experiments with fast rare isotopes at theNational Superconducting Cyclotron Laboratory (NSCL). Thisconsortium is joined by Ball State University, Central MichiganUniversity, Concordia College in Moorhead, Minn., Hope College,Indiana University at South Bend, Millikin University, WesternMichigan University, and Westmont College, each of which willassemble and test one complete layer of the detector.The proposed detector consists of 144 horizontal blocks of plasticscintillator arranged in 9 layers of 16 detectors each, covering anarea of 2.0 m wide by 1.6 m high. The detector is positionsensitive and features multi-hit capability. The addition ofpassive iron converters enhances the detection efficiency forneutrons with energies above 100 MeV for an average efficiency of upto 70%. The high detection efficiency will allow the investigationof very neutron-rich nuclei that can only be produced with smallintensities.The detector will be used in connection with the new sweeper magnetwith its focal plane detectors in stand-alone mode as well as withthe combination of sweeper magnet and the S800 magneticspectrograph. It will therefore be essential for the experimentalprogram at the coupled cyclotron facility. The detector can beoptimized for even higher beam energies with only minormodifications due to its modular design. It could be the firstdetector to be used for fast fragmentation beams at the Rare Isotope.