Development of BigBite: A Large Acceptance Magnetic Spectrometer for JLab

该提案将提供资金升级名为BigBite的探测器，该探测器将从目前位于荷兰的NIKHEF核物理设施转移到弗吉尼亚州纽波特纽斯的杰斐逊实验室（JLAB）。BigBite的广泛接受将补充JLAB A厅现有的两台高分辨率光谱仪，使实验能够在几个月或几周内完成，否则可能需要数年才能完成。与NIKHEF相比，该合同支持的升级将使BigBite在JLAB处理更高的计数率（高达6个数量级）。将使用BigBite的关键批准实验包括中性介子电产生的高精度测量（提供手性QCD动力学测试），高动量转移时中子电子形状因子的测量，以及通过三重巧合质子敲除反应研究原子核的短程性质。探测器的升级和实验本身将以一种必不可少的方式涉及学生和初级研究人员。

This proposal will provide funds to upgrade a detector known as BigBite, which will be moved from its present location at the NIKHEF nuclear physics facility in the Netherlands to Jefferson Laboratory (JLAB) in Newport News, Virginia. The large acceptance of BigBite will complement the two existing high-resolution spectrometers in Hall A at JLAB, enabling experiments to be completed in months or weeks that might otherwise have taken years to complete. The upgrade supported by this award will enable BigBite to handle themuch higher counting rates (up to six orders of magnitude) at JLAB compared to NIKHEF. Key approved experiments that will make use of BigBite include a high-precision measurment of neutral pion electroproduction (providing a test of chiral QCD dynamics), a measurement of the neutron electron form factor at high momentum transfer, and a study of short-range properties in nuclei via a triple-coincidence proton-knockout reaction. The detector upgrade and the experiments themselves will involved students and junior investigators in an essential way.