【作者】 曹成芳；

【导师】 贾焕玉；

【作者基本信息】 西南交通大学 ， 理论物理， 2008， 硕士

【摘要】 近年来,极高能宇宙线成为了宇宙线物理的研究热点,世界上有许多大的实验工作在这一能区,但各个实验的观测结果并不一致,有的甚至得出相反的结论。其中一个重要原因就是各实验能量标定精度无法比较。为了解决这一问题,中国科学家提出了宇宙线τ中微子望远镜实验(Cosmic Rays TauNeutrino Telescope,CRTNT)。截止2006年10月底,CRTNT已研制出两台样机,并且在西藏羊八井国际宇宙线观测站(30.11°N,90.53°E,海拔4300m)ARGO-YBJ实验附近进行安装,主要目的是为了调试探测器并且实现与ARGO-YBJ实验的联合观测,进而进行膝区物理的研究。本文是基于CRTNT在西藏羊八井试运行的两台样机的标定工作展开的,包括探测器的光电倍增管增益一致性标定和指向标定。光电倍增管是CRTNT成像系统中最基本的单元和复杂器件,精细的标定对CRTNT的能量分辩能力等物理性能有着重要意义。通过分析测量LED紫外光所得数据,找出各个PMT的绝对增益,从而对采集的切伦科夫光事例进行离线调节,使采集的数据更加符合真实数据,使簇射产生的切伦科夫辐射的强度能够得到准确地重建。另外通过分析宇宙线τ中微子望远镜(CRTNT)于2007年2月在西藏羊八井国际宇宙线观测站试运行期间采集的星空背景数据,对CRTNT进行了指向标定。首先用经纬仪以ARGO-YBJ大厅为参照物初步测量望远镜指向,再通过选取在CRTNT视场范围内看到的比较亮的恒星做参考,即把通过实验数据分析得到的恒星的赤经、赤纬与J2000星表中的经纬度进行比较后,微调初步测量的指向。望远镜的指向最终以不大于0.25°的精度确定为(207°,52.75°)。指向标定的完成为进一步用CRTNT的观测数据进行事例方向重建等奠定了重要的基础。更多还原

【Abstract】 In recent years,sub-EeV cosmic ray becomes hot topic of the cosmic ray physics.Many experiments study on this area of sub-EeV energy in the world.but the observation results from every experiment are inconsistent,some even concluded reverse results.One important reason for this is that the precision of energy calibration from every experiment can’t compare with each other.To overcome this difficulty, Chinese scientists invent Cosmic Rays Tau Neutrino Telescope(CRTNT).Up to end of October 2006,Two prototype telescopes have been constructed and mounted at the Yangbajing Cosmic Ray Observatory(30.11°N,90.53°E,4300m a.s.l.)near the ARGO-YBJ experiment site.This setup is used for debugging the telescopes and coincident measurement of cosmic ray showers for composition around knee region.This thesis is developed based on the calibration of the Cosmic Ray Tau Neutrinos Telescope(CRTNT)prototypes at Yangbajing building by IHEP of Chinese Academy of Sciences,the calibration of gain consistency of photomultiplier tubes and telescope pointing are included.The purpose of gain consistency calibration is compute the relative gain of every PMTs by analyzing the data through observing LED ultraviolet light,then the data of Cherenkov events from observation can be corrected offline,the corrected data will be more closed to true observation data,the energy of Cherenkov event from extensive air shower(EAS)can be constructed correctly. In addition,By analysing the data collected by Cosmic Rays Tau Neutrino Telescope(CRTNT)prototypes at Yangbajing through observing the sky background during February of 2007,the pointing calibration of the CRTNT has been done.During the calibration,the pointing of the CRTNT relative to the hall of ARGO-YBJ has been measured with the theodolite firstly,then the bright stars seen by CRTNT is taken as reference to calibrate the pointing.That is to say,the difference between the equatorial coordinates of the stars received from CRTNT and that from J2000 star table is used as reference to correct the pointing measured firstly.At the end,The pointing of the CRTNT is determined as(207°,52.75°)within 0.25°.The finishment of the pointing calibration is very important for the determining of the shower impact point and the reconstruction of primary direction of CRTNT.更多还原