The Energy Spectrum of Cosmic-Ray Electrons from 10 to 100 GeV Observed with a Highly Granulated Imaging Calorimeter
The Energy Spectrum of Cosmic-Ray Electrons from 10 to 100 GeV Observed with a Highly Granulated Imaging Calorimeter
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DOI：
10.1086/322274
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发表时间：
2001-10
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影响因子：
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通讯作者：
S. Torii;T. Tamura;N. Tateyama;K. Yoshida;J. Nishimura;T. Yamagami;H. Murakami;T. Kobayashi;Y. Komori;K. Kasahara;T. Yuda
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作者：
S. Torii;T. Tamura;N. Tateyama;K. Yoshida;J. Nishimura;T. Yamagami;H. Murakami;T. Kobayashi;Y. Komori;K. Kasahara;T. Yuda
利用一个新的球载有效载荷-带有闪烁光纤的球载电子望远镜（BETS）观测到了能量范围从12至~100 GeV的宇宙射线电子。这是第一次出版的绝对能量谱的电子测量与高度颗粒化的纤维量热计。量热计可以通过对纵向和横向簇射发展的详细观察，从背景质子中选择电子。探测器的性能由CERN-SPS加速器束校准：电子从5到100 GeV，质子从60到250 GeV。1997年和1998年在日本的Sanriku气球中心（空间和宇宙航行科学研究所）进行了两次气球观测。在34公里以上的高度，观测时间总共约为13小时。共收集了1349个电子候选者，其中628个事件的能量超过12.5 GeV，远高于地磁刚性截止~10 GV，已被用来组成一个微分绝对能谱在大气顶部。能谱的幂律指数为3.00 ± 0.09，10 GeV时的绝对微分强度为0.199 ± 0.015 m-2 s-1 sr-1 GeV-1。10 ~ 100 GeV能谱的整体形状可以用扩散模型来解释，在该模型中，我们假设注入谱的能量依赖扩散系数（E_0.3）为E-2.4。
Cosmic-ray electrons have been observed in the energy range from 12 to ~100 GeV with a new balloon-borne payload, the Balloon-borne Electron Telescope with Scintillating Fibers (BETS). This is the first publication of the absolute energy spectrum of electrons measured with a highly granulated fiber calorimeter. The calorimeter makes it possible to select electrons against the background protons by detailed observation of both the longitudinal and the lateral shower development. The performance of the detector was calibrated by the CERN-SPS accelerator beams: electrons from 5 to 100 GeV, protons from 60 to 250 GeV. The balloon observations were carried out twice, in 1997 and 1998, at the Sanriku Balloon Center (Institute of Space and Astronautical Science) in Japan. The observation time was ~13 hr in all at an altitude above 34 km. A total of 1349 electron candidates were collected, and the 628 events with energies above 12.5 GeV, well above the geomagnetic rigidity cutoff of ~10 GV, have been used to compose a differential absolute energy spectrum at the top of the atmosphere. The energy spectrum is described by a power-law index of 3.00 ± 0.09, and the absolute differential intensity at 10 GeV is 0.199 ± 0.015 m-2 s-1 sr-1 GeV-1. The overall shape of the energy spectrum in 10 ~ 100 GeV can be explained by a diffusion model, in which we assume an energy-dependent diffusion coefficient (∝ E0.3) for an injection spectrum, E-2.4.