论文标题
CLAS12向后角中子探测器（带）
The CLAS12 Backward Angle Neutron Detector (BAND)
论文作者
论文摘要
CLAS12的向后角中子检测器（频段）检测出$ 155^\ Circ $向后发射到$ 175^\ Circ $的中子，Momenta在$ 200 $至600美元之间。它位于目标上游3米的位置，包括$ 18 $行和5美元的$ 7.2 $ $ cm乘$ 7.2 $ $ $ CM闪烁的杆棒，并在PMT上读出两端，以测量闪烁剂层中的时间和能量沉积。在目标和带之间有一个2厘米厚的铅壁，然后是2厘米的否决层，以抑制伽玛并拒绝带电的颗粒。本文讨论了组件选择测试和检测器组件。使用新型的脉冲激光校准系统进行了定时校准（包括偏移和时间步行），从而使时间分辨率优于250美元$ PS（150 PS），以高于2 mevee（5 mevee）的能量沉积。宇宙射线和多种放射源用于校准检测器的能量响应。测量闪烁体杆衰减长度。时间分辨率导致中子动量重建分辨率，$ΔP/p <1.5 $ \％的中子动量$ 200 \ le p \ le p \ le 600 $ meV/c。显示了带有CLAS12的频带的最终性能，包括电子中性粒子的时序光谱以及对禁止中性污染作为能量沉积阈值的函数的讨论。
The Backward Angle Neutron Detector (BAND) of CLAS12 detects neutrons emitted at backward angles of $155^\circ$ to $175^\circ$, with momenta between $200$ and $600$ MeV/c. It is positioned 3 meters upstream of the target, consists of $18$ rows and $5$ layers of $7.2$ cm by $7.2$ cm scintillator bars, and read out on both ends by PMTs to measure time and energy deposition in the scintillator layers. Between the target and BAND there is a 2 cm thick lead wall followed by a 2 cm veto layer to suppress gammas and reject charged particles. This paper discusses the component-selection tests and the detector assembly. Timing calibrations (including offsets and time-walk) were performed using a novel pulsed-laser calibration system, resulting in time resolutions better than $250$ ps (150 ps) for energy depositions above 2 MeVee (5 MeVee). Cosmic rays and a variety of radioactive sources were used to calibration the energy response of the detector. Scintillator bar attenuation lengths were measured. The time resolution results in a neutron momentum reconstruction resolution, $δp/p < 1.5$\% for neutron momentum $200\le p\le 600$ MeV/c. Final performance of the BAND with CLAS12 is shown, including electron-neutral particle timing spectra and a discussion of the off-time neutral contamination as a function of energy deposition threshold.
