Köhn Christoph, Diniz Gabriel, Harakeh Muhsin N
DTU Space, National Space Institute Technical University of Denmark Lyngby Denmark; Center for Mathematics and Computer Science CWI Amsterdam Netherlands.
Instituto Nacional de Pesquisas Espaciais São José dos Campos Brazil; Instituto de Física Universidade de Brasília Brasília Brazil.
J Geophys Res Atmos. 2017 Jan 27;122(2):1365-1383. doi: 10.1002/2016JD025445.
It has been discussed that lightning flashes emit high-energy electrons, positrons, photons, and neutrons with single energies of several tens of MeV. In the first part of this paper we study the absorption of neutron beams in the atmosphere. We initiate neutron beams of initial energies of 350 keV, 10 MeV, and 20 MeV at source altitudes of 4 km and 16 km upward and downward and see that in all these cases neutrons reach ground altitudes and that the cross-section areas extend to several km. We estimate that for terrestrial gamma-ray flashes approximately between 10 and 2000 neutrons per ms and m are possibly detectable at ground, at 6 km, or at 500 km altitude. In the second part of the paper we discuss a feedback model involving the generation and motion of electrons, positrons, neutrons, protons, and photons close to the vicinity of lightning leaders. In contrast to other feedback models, we do not consider large-scale thundercloud fields but enhanced fields of lightning leaders. We launch different photon and electron beams upward at 4 km altitude. We present the spatial and energy distribution of leptons, hadrons, and photons after different times and see that leptons, hadrons, and photons with energies of at least 40 MeV are produced. Because of their high rest mass hadrons are measurable on a longer time scale than leptons and photons. The feedback mechanism together with the field enhancement by lightning leaders yields particle energies even above 40 MeV measurable at satellite altitudes.
已经讨论过闪电会发射出单能几十兆电子伏特的高能电子、正电子、光子和中子。在本文的第一部分,我们研究了中子束在大气中的吸收情况。我们在4千米和16千米的源高度向上和向下引发初始能量为350千电子伏特、10兆电子伏特和20兆电子伏特的中子束,发现在所有这些情况下中子都能到达地面高度,并且横截面面积延伸到几千米。我们估计,对于地面伽马射线闪光,在地面、6千米或500千米高度处,每毫秒每米可能检测到大约10到2000个中子。在本文的第二部分,我们讨论了一个涉及闪电先导附近电子、正电子、中子、质子和光子的产生和运动的反馈模型。与其他反馈模型不同,我们不考虑大规模雷暴云场,而是考虑闪电先导的增强场。我们在4千米高度向上发射不同的光子和电子束。我们给出了不同时间后轻子、强子和光子的空间和能量分布,发现产生了能量至少为40兆电子伏特的轻子、强子和光子。由于强子的静止质量很高,它们在比轻子和光子更长的时间尺度上是可测量的。反馈机制与闪电先导引起的场增强一起,产生了甚至在卫星高度可测量的高于40兆电子伏特的粒子能量。