Charge Dependence of Cosmic Ray Solar Modulation

太阳风携带的不规则磁场将带电粒子扫出太阳系，并导致宇宙射线通量与太阳活动水平之间的反相关。由于电子和原子核的电荷质量比有很大的不同，这两种粒子的速度和磁刚性的关系也有很大的不同。如果日球磁场具有长程序，宇宙射线粒子的电荷符号会影响其传播。最近的观测表明，同时再现电子和核子调制的电流调制模型的主要失败与每11年发生一次的太阳磁场反转有关。那么，当太阳场反转时，电荷依赖应该会改变，但与观察到的不同。pi将开展一项研究计划，通过一系列气球飞行来扩展宇宙射线太阳调制的电荷依赖性测量，以确定电子和正电子通量在广泛能量范围内的时间依赖性。这一研究将确定日球层磁场的大尺度阶对确定日球层带电粒子的运动轨迹的重要性。

Magnetic field irregularities carried by the solar wind sweep charged particles out of the solar system and cause the anti-correlation between cosmic ray fluxes and the level of solar activity. Since electrons and nuclei have greatly different charge/mass ratios, the relation of velocity and magnetic rigidity is significantly different for these two particle species. If the heliospheric magnetic field has long range order, the charge sign of cosmic ray particles can affect their propagation. Recent observations show that a major failure of current modulation models simultaneously reproducing electron and nucleon modulation is related to reversals of the solar magnetic field, which occur every eleven years. Charge dependence, then, should change when the solar field reverses, but differently from that observed. The PIs will conduct a research program extending measurements of charge dependence of cosmic ray solar modulation with a series of balloon flights to determine the time dependence of electron and positron fluxes over a broad energy range. This investigation will determine the importance of large scale order of the heliospheric magnetic field in determining trajectories of charged particles in the heliosphere.