The Simulation Of LHAASO-KM2A Array's In Knee Area

Since the beginning of the last century has been found in cosmic rays, origin and acceleration mechanism of cosmic rays has been a fundamental problem of particle astrophysics. The knee region of cosmic ray (1014~1016eV) are very sensitive to this problem, The correct interpretation of the cause of the knee region will play a decisive role to answer the problem. This interpretation depends on the energy spectrum and composition measurements for the cosmic rays in the knee region. All along, many aimed at this goal of scientists conducted a number of experiments using various means of observing the knee region. But the various experiments are inconsistent with the energy spectrum, especially in the knee region, the compositions still differ in uncertainty of about 30%.LHAASO project (Large High Altitude Air Shower Observatory, a large high-altitude air shower observatories) is planning to establish 1km2 detector array at the YBJ research centers in Tibet. Using a variety of detection means, precise observation, take full advantage of YBJ Centre 4300m altitude, and strengthen international co-operation, greatly improving high-energy cosmic rays detection capabilities which the other experimentals can not compared.The KM2A array in LHAASO projects which constituted with electronic andμdetectors. This article simulate the array, use the sensitivity above 30TeV energy region to optimize the array, to study the array of measured cosmic ray spectrum in the knee region and the identification of each component capacity.This can be roughly divided into the following parts:The first chapter introduces the origin and acceleration mechanism of cosmic rays and the national and international research progress in the knee region.The second chapter introduces the scientific objectives of the LHAASO project and the basic settings with the KM2A array detector and trigger conditions and data acquisition.The third chapter make a detailed introduction of the EAS simulated data generated, the LHAASO-KM2A simulation program, the parameters of the detector response and the analysis of the data. The fourth chapter describes the optimization of KM2A array. Using the program to caculated the results of angle-resolved, effective area, g/p resolution and sensitivity of the KM2A array. In different detection area and time accuracy, simulated the results of sensitivity of the KM2A array, and based on the results to acquire optimization of the KM2A array.The fifth chapter introduces the simulation of the knee region with the KM2A array. Measurement of the energy spectrum in the knee region, and identify the compositon of cosmic rays of light nuclei, the moderate nuclei and the heavy nuclei.The sixth chapter summarizes this work and look forward to the contribution of the LHAASO projects may make on cosmic ray physics.