By accurately measuring composition and energy spectrum of cosmic ray, the origin problem of so called “knee” region (energy >one PeV) can be solved. However, up to the present, the results of the spectrum in the knee region obtained by several previous experiments have shown obvious differences, so they cannot give effective evidence for judging the theoretical models on the origin of the knee. Recently, the Large High Altitude Air Shower Observatory (LHAASO) has reported several major breakthroughs and important results in astro-particle physics field. Relying on its advantages of wide-sky survey, high altitude location and large area detector arrays, the research content of LHAASO experiment mainly includes ultra high-energy gamma-ray astronomy, measurement of cosmic ray spectra in the knee region, searching for dark matter and new phenomena of particle physics at higher energy. The electron and thermal neutron detector (EN-Detector) is a new scintillator detector which applies thermal neutron detection technology to measure cosmic ray extensive air shower (EAS). This technology is an extension of LHAASO. The EN-Detector Array (ENDA) can highly efficiently measure thermal neutrons generated by secondary hadrons so called “skeleton” of EAS. In this paper, we perform the optimization of ENDA configuration, and obtain expectations on the ENDA results, including thermal neutron distribution, trigger efficiency and capability of cosmic ray composition separation. The obtained real data results are consistent with those by the Monte Carlo simulation.

通过精确测量宇宙射线的成分和能谱，可以解决所谓“拐点”区（能量>1 PeV）的起源问题。然而，到目前为止，之前的几次实验获得的膝部区域的光谱结果都表现出明显的差异，因此无法为判断膝部起源的理论模型提供有效的证据。近日，大型高空空气簇射天文台（LHAASO）报道了天体粒子物理领域的多项重大突破和重要成果。依托其广天巡天、高空定位和大面积探测器阵列的优势，LHAASO实验的研究内容主要包括超高能伽马射线天文学、膝区宇宙射线谱测量、寻找暗物质等以及高能粒子物理的新现象。电子热中子探测器（EN-Detector）是一种应用热中子探测技术测量宇宙射线广延空气簇射（EAS）的新型闪烁体探测器。该技术是LHAASO的延伸。 EN 探测器阵列 (ENDA) 可以高效测量二次强子产生的热中子，即 EAS 的“骨架”。在本文中，我们对ENDA配置进行了优化，并获得了对ENDA结果的预期，包括热中子分布、触发效率和宇宙线成分分离能力。得到的真实数据结果与蒙特卡罗模拟结果一致。