Latitude and altitude dependence of the cosmic ray albedo neutron flux
Latitude and altitude dependence of the cosmic ray albedo neutron flux
复制标题
宇宙射线反照率中子通量的纬度和高度依赖性
DOI：
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发表时间：
1970
期刊：
影响因子：
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通讯作者：
E. Chupp
中科院分区：
文献类型：
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作者：
R. Jenkins;J. Lockwood;S. Ifedili;E. Chupp
在1969年6月7日至17日期间，对400公里以上的宇宙射线反照率中子通量进行了初步测量。测量是由Ogo 6卫星上的探测器完成的，该探测器主要对能量范围在104至106 ev的中子做出反应。计数率的纬度变化在90°和0°之间为7.4/1，与Lingenfelter（1963）的预测相似。两极附近的中子计数率在450 ~ 950 km高度之间下降了26±5%，对应于R - 4.2±0.9的依赖关系，其中R是到地球中心的距离。这种高度依赖性排除了大气顶部中子通量的任何角分布，这些角分布在垂直方向上比cos θ（其中θ是与垂直方向的夹角）更有峰值，但它与各向同性中子通量并不矛盾。假设各向同性得到的中子泄漏总通量约为Lingenfelter（1963）预测的0.7倍。在相同的角度分布下，Ogo 6实验得到的中子泄漏通量值与其他具有相似中子能量响应的实验结果一致。利用Lingenfelter（1963）和Newkirk（1963）的泄漏中子能谱，从只响应于1 Mev以上的中子的实验中推断出的总中子泄漏通量的估计，在使用Newkirk能谱时与较低能量的结果一致，但在使用Lingenfelter能谱时，其结果高达较低能量结果的两倍。
Preliminary measurements of the cosmic ray albedo neutron flux above 400 km are reported for the period June 7 to 17, 1969. The measurements were made with a detector on board the Ogo 6 satellite that responds primarily to neutrons in the energy range 104 to 106 ev. The latitude variation of the counting rate was found to be 7.4/1 between 90° and 0°, similar to that predicted by Lingenfelter (1963). The neutron counting rate near the poles was found to decrease by 26±5% between 450 and 950 km altitude, corresponding to a R−4.2±0.9 dependence, where R is the distance from the center of the earth. This large altitude dependence excludes any angular distributions of neutron flux at the top of the atmosphere that are more peaked toward the vertical than cos θ (where θ is the angle from the vertical), but it is not in disagreement with an isotropic neutron flux. The total neutron leakage flux found by assuming isotropy was about 0.7 times that predicted by Lingenfelter (1963). The neutron leakage flux values obtained from the Ogo 6 experiment agree with those estimated from other experiments with a similar neutron energy response, if the same angular distribution is used. Estimates of the total neutron leakage flux, deduced from experiments responsive only to neutrons above 1 Mev by using the Lingenfelter (1963) and Newkirk (1963) energy spectra of leakage neutrons, show agreement with the lower energy results when the Newkirk spectrum is used but are up to twice as great as the lower energy results when the Lingenfelter spectrum is applied.