Laboratory Measurements of Fast Hydrogen (H) and Oxygen (O) Atom Collisions Relevant to the Upper Atmosphere

通过光解离、辐射复合、解离复合、解离附着、电荷交换和超弹性（淬火）碰撞等现象，在地球高层大气中产生能量范围为 1-100 eV 及更高的快速氢、氮和氧原子。其中许多现象是由闪电放电引起的，闪电放电导致了被称为精灵、红色精灵和蓝色喷射的排放。快速原子与N2、O2、NO、H2O、CO2等物质碰撞，通过化学反应或直接激发目标，在高层大气和热层中产生排放，例如氢夜间和极尖极光，以及热氧日冕和地日冕。使用 JPL 的独特实验设施（在 NSF 先前的支持下建造），将在实验室能量范围 2-100 eV 内产生快速基态氢和氧原子。快原子将用于研究重要物质 N2、O2 和 NO 的两类大气反应。这些类别是 (a) 红外（振动）激发和发射，其中使用与 HgCdTe 红外探测器耦合的积分球测量横截面； (b) 电子捕获和剥离，其中使用潘宁离子阱进行横截面和质荷比测量。

Fast hydrogen, nitrogen, and oxygen atoms in the energy range 1-100 eV and higher are produced in the earth's upper atmosphere through phenomena such as photodissociation, radiative recombination, dissociative recombination, dissociative attachment, charge exchange, and superelastic (quenching) collisions. Many of these phenomena are induced by lightning discharges, which are responsible for emissions known as elves, red sprites, and blue jets. The fast atoms collide with species such as N2, O2, NO, H2O, CO2, etc. to produce, either through chemical reaction or direct excitation of the target, emissions in the upper atmosphere and thermosphere such as the hydrogen nighttime and polar-cusp aurora, and the hot oxygen corona and geocorona. Using a unique experimental facility at JPL, constructed with prior NSF support, fast ground-state hydrogen and oxygen atoms will be generated in the laboratory energy range 2-100 eV. The fast atoms will be used to study two classes of atmospheric reactions with the important species N2, O2, and NO. These classes are (a) infrared (vibrational) excitation and emission, where cross sections are measured using an integrating sphere coupled to a HgCdTe infrared detector; and (b) electron-capture and stripping, where cross-section and mass/charge ratio measurements are made using a Penning ion trap.