论文标题
对伽马射线观测的气压校正及其能量依赖性
Barometric Pressure Correction to Gamma-ray Observations and its Energy Dependence
论文作者
论文摘要
在上个世纪，已经对宇宙射线（CRS）进行了广泛的研究，以了解宇宙和太阳系中的过程。在当今的卫星时代，尽管许多观察结果是由太空进行的，但地面的CR观察仍然被视为重要的工具。然而，这些观察结果主要检测到次级宇宙射线（SCR），例如中子，Muon和Gamma。众所周知，大气压在地面观察到的SCR通量中起着重要作用。气压校正是中子监视器（NM）数据的标准实践。但是，没有对伽马射线进行这种校正，无质量。但是压力会影响粒子，例如$ e^{\ pm} $，$μ^{\ pm} $，在级联中产生伽马射线。随后，可以预期伽马射线通量的间接压力依赖性。 我们通过研究NAI（TL）检测器检测到的伽马射线计数来详细研究这一方面。本研究证实，大气压力与从所有能量收集的总伽马射线计数之间没有相关性。但是，当分别研究不同能量的伽马射线通量时，情况有所不同。低于$ \ sim $ 3 MEV的能量的伽玛射线主要是由于地面的放射性，而3 MeV以上的伽马射线主要是在CR Cascade中生产的。据观察，高于3 MeV的能量计数与大气压力较为抗相关，因此需要纠正。事实证明，应用气压校正公式成功地消除了3 MeV高于3 MeV的伽马射线中的压力依赖性。因此，我们建议需要对3 MEV的伽马射线数据进行局部大气压力变化进行校正。
Cosmic rays (CRs) have been studied extensively in the last century to understand the processes in the universe as well as in the solar system. In today's satellite era, although many observations are made from space, CR observations from the ground are still viewed as an important tool. These observations, however, mostly detect the secondary cosmic rays (SCRs) such as neutron, muon, and gamma. It is well known that the atmospheric pressure plays an important role in the SCR flux observed on the ground. Barometric pressure correction is standard practice for neutron monitor (NM) data. However, no such correction is applied to gamma-ray, being massless. But the pressure affects the particles such as $e^{\pm}$, $μ^{\pm}$, which produce gamma rays in the cascade. Subsequently, the indirect pressure dependence of the gamma-ray flux can be anticipated. We examine this aspect in detail by studying the gamma-ray counts detected by the NaI (Tl) detector. The present study confirms that there is no correlation between the atmospheric pressure and the total gamma-ray counts collected from all energies. However, the scenario differs when the gamma-ray fluxes of different energies are investigated separately. The gamma rays of energy below $\sim$3 MeV are primarily due to the radioactivity originating from the ground, whereas gamma rays above 3 MeV are mainly produced in the CR cascade. It is observed that the counts of energy above 3 MeV are well anti-correlated with the atmospheric pressure and hence need to be corrected. It is demonstrated that applying the barometric correction formula successfully removes the pressure dependence in the gamma-ray flux above 3 MeV. Therefore, we suggest that the gamma-ray data above 3 MeV needs to be corrected for the local atmospheric pressure variations.
