高海拔宇宙线观测站(Large High Altitude Air Shower Observatory,LHAASO)主要用于探索高能宇宙线起源、高能天体演化以及新物理前沿等。其中的大面积缪子探测器(Muon Detector,MD)阵列,具有对原初伽马射线的高鉴别能力,能够完成超高...高海拔宇宙线观测站(Large High Altitude Air Shower Observatory,LHAASO)主要用于探索高能宇宙线起源、高能天体演化以及新物理前沿等。其中的大面积缪子探测器(Muon Detector,MD)阵列,具有对原初伽马射线的高鉴别能力,能够完成超高能伽马射线的高灵敏度探测。缪子探测器通过阳极和第七打拿极两路信号共同读出的方式,实现1~10000个缪子的大动态范围探测。为了减小在阳极信号饱和后的区域,直接转换为打拿极信号进行测量的误差,提出了将阳极(阳极未饱和部分)和打拿极(阳极饱和部分)两部分信号进行拼接测量的电荷测量优化方案。通过数值模拟得出阳极与打拿极之间的连接方式,可以采用实验室标定的阳极、打拿极关系进行连接。数值模拟结果表明,该方案在1~10000个缪子的大动态范围内有效降低了测量误差,误差小于1%,缪子谱结构得到明显改善。利用全波形信号进行数据分析的结果与模拟结果很好符合,验证了该方案的有效性。展开更多
The full array of the Large High Altitude Air Shower Observatory(LHAASO)has been in operation since July 2021.For its kilometer-square array(KM2A),we optimized the selection criteria for very high and ultrahigh energy...The full array of the Large High Altitude Air Shower Observatory(LHAASO)has been in operation since July 2021.For its kilometer-square array(KM2A),we optimized the selection criteria for very high and ultrahigh energyγ-rays using data collected from August 2021 to August 2022,resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%,compared with that of previous cuts.With the implementation of these new selection criteria,the angular resolution was also significantly improved by approximately 10%at tens of TeV.Other aspects of the full KM2A array performance,such as the pointing error,were also calibrated using the Crab Nebula.The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model,which is consistent with the previous results from LHAASO and other experiments.展开更多
文摘高海拔宇宙线观测站(Large High Altitude Air Shower Observatory,LHAASO)主要用于探索高能宇宙线起源、高能天体演化以及新物理前沿等。其中的大面积缪子探测器(Muon Detector,MD)阵列,具有对原初伽马射线的高鉴别能力,能够完成超高能伽马射线的高灵敏度探测。缪子探测器通过阳极和第七打拿极两路信号共同读出的方式,实现1~10000个缪子的大动态范围探测。为了减小在阳极信号饱和后的区域,直接转换为打拿极信号进行测量的误差,提出了将阳极(阳极未饱和部分)和打拿极(阳极饱和部分)两部分信号进行拼接测量的电荷测量优化方案。通过数值模拟得出阳极与打拿极之间的连接方式,可以采用实验室标定的阳极、打拿极关系进行连接。数值模拟结果表明,该方案在1~10000个缪子的大动态范围内有效降低了测量误差,误差小于1%,缪子谱结构得到明显改善。利用全波形信号进行数据分析的结果与模拟结果很好符合,验证了该方案的有效性。
基金Supported by the National Key R&D Program of China(2018YFA0404201,2018YFA0404202,2018YFA0404203,2018YFA0404204)the National Natural Science Foundation of China(12022502,12205314,12105301,12261160362,12105294,U1931201)+2 种基金the Youth Innovation Promotion Association CAS(2022010)in Thailand by the National Science and Technology Development Agency(NSTDA)the National Research Council of Thailand(NRCT):High-Potential Research Team Grant Program(N42A650868)。
文摘The full array of the Large High Altitude Air Shower Observatory(LHAASO)has been in operation since July 2021.For its kilometer-square array(KM2A),we optimized the selection criteria for very high and ultrahigh energyγ-rays using data collected from August 2021 to August 2022,resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%,compared with that of previous cuts.With the implementation of these new selection criteria,the angular resolution was also significantly improved by approximately 10%at tens of TeV.Other aspects of the full KM2A array performance,such as the pointing error,were also calibrated using the Crab Nebula.The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model,which is consistent with the previous results from LHAASO and other experiments.
