The vertical component of 1--20 MeV gamma rays at balloon altitudes
The vertical component of 1--20 MeV gamma rays at balloon altitudes
复制标题
气球高度处 1--20 MeV 伽马射线的垂直分量
DOI：
10.1086/158239
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
F. Penningsfeld
中科院分区：
文献类型：
--
作者：
V. Schoenfelder;F. Graml;F. Penningsfeld
根据Max-Planck研究所大面积康普顿望远镜在气球飞行过程中获得的伽马射线数据，确定了1-20 MeV伽马射线的漫射宇宙和垂直大气成分。与第一代康普顿望远镜以前的测量相比，这种新测量的基本改进是基于这样一个事实，即对于每个登记的事件，各种附加参数都是确定的。通过向上散射伽马射线的飞行时间分布和中子诱发事件的脉冲形状测量，可以从数据本身确定大多数不需要的背景事件。由此得到的来自高银河系纬度的宇宙伽马射线的能谱支持在MeV能量处的能谱中存在凹凸，高于硬X射线能量的外推。在大约5 MeV以上，光谱变得非常陡峭，并很好地连接到35到200 MeV之间的SAS 2测量结果。下移大气伽马射线在1到20 MeV之间的垂直分量可以用一个单一的幂定律来拟合：(6+-1)x10/sup-3/E/sup()-1.65正负0.15/光子cm/sup-2/S/sup-1/sr/sup-1/mev/sup-1/g/sup-1/cm/sup 2/。讨论了漫射宇宙伽马射线分量的起源问题，并将大气伽马射线分量的计算结果与不同模型的计算结果进行了比较。
From the gamma-ray data obtained during a balloon flight of the large-area Compton telescope of the Max-Planck-Institut, the diffuse cosmic and the vertical atmospheric component of 1--20 MeV gamma rays were determined. The basic improvement of this new measurement above previous measurements with a first version of the Compton telescope is based on the fact that for each registered event various additional parameters are determined. By means of the time-of-flight distribution of upward-scattered gamma rays and by means of the pulse shape measurement of neutron-induced events it is possible to determine most of the undesired background events from the data themselves. The resulting energy spectrum of cosmic gamma rays from high galactic latitudes supports the existence of bump in the spectrum at MeV energies above the extrapolation from hard X-ray energies. Above about 5 MeV the spectrum becomes very steep and nicely connects to the SAS 2 measurements between 35 and 200 MeV. The vertical component of downward-moving atmospheric gamma rays between 1 and 20 MeV can be fitted by one single power law: (6 +- 1) x 10/sup -3/ E/sup() -1.65plus-or-minus0.15/ photons cm/sup -2/ s/sup -1/ sr/sup -1/ MeV/sup -1/ g/sup -1/ cm/sup 2/. The question about the originmore » of the diffuse cosmic gamma-ray component is discussed, and the results about the atmospheric gamma-ray component are compared with different models calculations.« less