Proton and Helium Spectra from the CREAM-III Flight
Proton and Helium Spectra from the CREAM-III Flight
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DOI：
10.3847/1538-4357/aa68e4
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发表时间：
2017-04
期刊：
影响因子：
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通讯作者：
Y. Yoon;T. Anderson;A. Barrau;N. Conklin;S. Coutu;L. Derome;J. Han;J. Jeon;K. C. Kim;
中科院分区：
文献类型：
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作者：
Y. Yoon;T. Anderson;A. Barrau;N. Conklin;S. Coutu;L. Derome;J. Han;J. Jeon;K. C. Kim;
自2004年以来，球载宇宙线能量和质量（CREAM）实验已经测量了初级宇宙线元素光谱。第三个CREAM有效载荷（CREAM-III）在2007-2008年南极季节飞行了29天。能量超过1 TeV的入射粒子的能量是用量热计测量的。使用两层硅电荷探测器，质子和氦核的电荷分辨率分别为10.12 e（以电荷单位计）和10.14 e。在大气层顶部测得的质子和氦能谱比其他现有的几十GeV的测量更难。在1 TeV/n ~ 63 TeV/n范围内，质子相对于氦核的相对丰度为9.53 ± 0.03。这个比率比其他测量值小得多，只有几十GeV/n。当能量超过1020 TeV时，谱线变得较软。然而，在这些能量下，我们的统计不确定性很大，需要更多的数据。
Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007–2008 Antarctic season. Energies of incident particles above 1 TeV are measured with a calorimeter. Individual elements are clearly separated with a charge resolution of ∼0.12 e (in charge units) and ∼0.14 e for protons and helium nuclei, respectively, using two layers of silicon charge detectors. The measured proton and helium energy spectra at the top of the atmosphere are harder than other existing measurements at a few tens of GeV. The relative abundance of protons to helium nuclei is 9.53 ± 0.03 for the range of 1 TeV/n to 63 TeV/n. This ratio is considerably smaller than other measurements at a few tens of GeV/n. The spectra become softer above ∼20 TeV. However, our statistical uncertainties are large at these energies and more data are needed.