用羊八井实验数据对宇宙线大尺度各向异性稳定性的研究

发布时间：2018-06-04 14:37

本文选题：宇宙线大尺度各向异性 + AS(?)　；参考：《河北师范大学》2016年硕士论文

【摘要】：世界上多家实验的结果表明,宇宙线在千分之一的量级上表现出了各向异性的结构,但不同的实验在某些细节上还存在着一定差异,分析这一结果的起因将有助于我们了解宇宙线起源及星际磁场结构的更多信息。本工作利用了羊八井宇宙线观测站高海拔(4300m)、宽视场等地理上的优势,采用了AS ?实验的数据,利用基于等天顶角方法的χ2迭代来分析宇宙线的大尺度各向异性,主要研究宇宙线各向异性是否对时间以及能量存在依赖关系。从年分布的结果中发现各向异性的振幅较为稳定,随着时间的推移只有万分之几的增长,而相位则表现出了与太阳活动相关的周期性变化。从季节分布的结果中发现了季节的调制,我们猜测这种季节调制可能是由地球在公转过程中所经过的星际磁场影响的。宇宙线在到达地球前要经过宇宙空间磁场的调制,而太阳作为离地球最近的源,其活动对探测到的宇宙线尤其是低能宇宙线的影响较大。低能段宇宙线随着时间的推移其振幅和相位都有较大的变化,且较低能段的宇宙线相位随时间的变化逐渐接近较高能段的相位,这个变化与太阳活动周期一致,即是在太阳活动较剧烈的年份高低能段宇宙线相位的差异较大,而在太阳活动较平静的年份,高低能段宇宙线的相位几乎一致。由于低能宇宙线更易受到太阳磁场的影响,我们推测宇宙线各向异性的相位变化与太阳活动相关。为了探究宇宙线能量对各向异性的影响,本文把AS ?实验数据分成了四个能段,发现随能量的增加相对强度有增加的趋势。且能量越高其拟合振幅和相位的变化越大,我们推测这与星际磁场相关。按异常结构所在的位置把天区分成四个区域,对每个区域分别进行研究,发现A、C区相对强度随着能量的增加表现出了先增强后减弱的趋势,且这两个区域呈现出了双极结构特征。而B、D区的相对强度则大小相似且较为稳定。由此我们推测虽然A区B区在全天区的位置相近且都是超出的结构但其形成的物理机制是不同的。本文的结构如下:第一章简单介绍了宇宙线的成分、能谱以及采用不同方法对宇宙线进行探测的几组实验。并介绍了什么是宇宙线大尺度各向异性以及各向异性都有什么样的结构。第二章介绍了位于羊八井的AS ?和ARGO两个实验的基本情况及探测原理,并简单介绍了本工作所采用的研究方法。第三章介绍了宇宙线大尺度各向异性的时间调制。发现宇宙线存在与太阳活动周期相关的变化规律,且每一年中间两个季度的各向异性相对强度大于另外两个季度的强度。由高低能段相位年变化的规律发现,太阳活动越剧烈,高低能宇宙线各向异性的相位差越大。第四章主要介绍了宇宙线大尺度各向异性的能量依赖。通过AS ?实验各个能段结果的对比发现能量越高各向异性现象越明显,第五章对上述实验的结果进行了总结并针对AS ?实验观测到的季节调制对比了ARGO实验的结果。最后介绍了未来还需要做哪些工作。
[Abstract]:The results of a number of experiments in the world show that the cosmic ray shows an anisotropic structure on the magnitude of 1/1000, but there are some differences in some details. The cause of the analysis will help us to understand more information about the origin of the cosmic ray and the structure of the interstellar magnetic field. The advantages of the high elevation (4300m) and wide field of view of the cosmic ray observatory, using the data of the AS? Experiment, using the chi 2 iteration based on the equal zenith angle method to analyze the large scale anisotropy of the cosmic ray, mainly to study whether the anisotropy of the cosmic ray is dependent on time and energy. The amplitude of the sex is more stable, with only a ten thousandth of growth over time, while the phase shows periodic changes associated with solar activity. The seasonal modulation is found from the results of the seasonal distribution, and we speculate that this seasonal modulation may be influenced by the earth's interstellar magnetic field through the process of the revolution. The universe is modulated by the space magnetic field before reaching the earth, and the sun, as the closest source to the earth, has a greater influence on the detected cosmic rays, especially the low energy cosmic rays. The amplitude and phase of the cosmic lines in the low energy section vary greatly with time, and the phase of the cosmic line in the lower energy section varies with time. It is close to the phase of the higher energy segment, which is in accordance with the solar activity cycle, that is, the phase of the cosmic ray of the high and low solar activity is larger, and the phase of the high and low cosmic ray is almost identical in the relatively quiet year of the solar activity, and we push the low energy cosmic ray to be more susceptible to the sun's magnetic field. The phase change of the anisotropy of the cosmic ray is related to the solar activity. In order to explore the influence of cosmic ray energy on the anisotropy, this paper divides the AS? Experimental data into four energy segments, and finds that the relative intensity increases with the increase of energy. And the higher the energy is, the greater the variation of the fitting amplitude and phase, we speculate that this is with the interstellar magnetic field. Field correlation. According to the location of the abnormal structure, the area is divided into four regions, and each region is studied separately. The relative intensity of A, C region shows a tendency to increase first and then weaken with the increase of energy, and the two regions show a bipolar structure characteristic. And the relative intensity of B, D region is similar and more stable. We speculate that although the B region of the A region is close to the whole day area and is all beyond the structure, the physical mechanism of the formation is different. The structure of this article is as follows: the first chapter briefly introduces the composition of the cosmic ray, the energy spectrum, and several groups of experiments using different methods to detect the cosmic ray. What is the structure of the anisotropy and the anisotropy. The second chapter introduces the basic conditions and detection principles of two experiments of AS? And ARGO in Yang eight well, and briefly introduces the research methods used in this work. The third chapter introduces the time adjustment of the large scale anisotropy of the cosmic ray. The relative intensity of the variation in the two quarter of each year is greater than that of the other two quarters. It is found that the solar activity is more intense and the phase difference of the anisotropy of the cosmic line is greater. The fourth chapter mainly introduces the energy dependence of the large scale anisotropy of the cosmic ray. Through the comparison of the results of each energy section of the AS experiment, it is found that the higher the energy anisotropy is, the fifth chapter summarizes the results of the above experiments and compares the results of the ARGO experiment with the seasonal modulation observed by the AS experiment. Finally, it introduces what needs to be done in the future.
【学位授予单位】：河北师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P172.4

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