Charge Dependence of Cosmic Ray Solar Modulation

宇宙线太阳调制的电荷依赖性

• 批准号: 9115492
• 负责人: Paul Evenson
• 金额: $ 29万
• 依托单位: Bartol Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-11-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9115492&HistoricalAwards=false
• 关键词: Charge; Dependence; Cosmic; Ray; Solar

The anti-correlation between cosmic ray fluxes and the level of solar activity (solar modulation) is caused by magnetic field irregularities carried by the solar wind that sweep charged particles out of the solar system and/or decelerate them. 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. A major failure of current modulation model simultaneously to reproduce electron and nucleon modulation is related to reversals of the solar magnetic field which occur every eleven years. Charge dependence should change when the solar field reverses, but in a way different from what is observed. The PIs propose a research program designed to extend measurements of charge dependence of cosmic ray solar modulation through comparison of electron data to be obtained under this proposal with electron and proton data available from an instrument on the ICE spacecraft as well as other data from the literature. This investigation will determine the extent to which large scale order of the heliospheric magnetic field is important in determining trajectories of charged particles in the heliosphere.

宇宙射线通量与太阳活动水平(太阳调制)之间的反相关性是由太阳风携带的磁场不规则性造成的，该磁场将带电粒子扫出太阳系并/或使其减速。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。如果日球层磁场具有长程有序，宇宙线粒子的电荷符号会影响其传播。电流调制模型不能同时再现电子和核子调制的一个重大失败与每11年发生一次的太阳磁场逆转有关。当太阳场反转时，电荷相关性应该会改变，但方式与观察到的不同。PIS提出了一项研究计划，旨在通过将根据这一建议获得的电子数据与ICE航天器上的仪器提供的电子和质子数据以及文献中的其他数据进行比较，扩大对宇宙线太阳调制电荷依赖性的测量。这项研究将确定日球层磁场的大尺度有序在多大程度上对确定日球层中带电粒子的轨迹很重要。