Consolidated Grant in Solar Physics

等离子体的物理学——尤其是被磁场渗透的等离子体——决定了可见宇宙的大部分行为。近在咫尺，我们需要了解和测量等离子体、场和粒子，了解动态的太阳及其与日球层的相互作用。在本提案中，我们将重点关注太阳物理学中几个尚未解决的关键问题，这些问题也是对整个宇宙等离子体进行更广泛和更深入了解的原型。我们的首要问题是：高能辐射粒子在太阳耀斑和行星际空间中的表现如何？它们是如何加速的，它们是如何发射的，它们在耀斑及其对地球的影响中起关键作用吗？太阳是如何在其磁化的大气层中储存和释放能量的，我们可以通过计算机模拟和研究其发射的辐射来了解这个过程吗？磁场是太阳大气中一切活动的关键。集中的磁场区域穿过太阳表面进入大气层。在这里，它们与预先存在的磁场相互作用，结果是被称为耀斑的强烈能量爆发，它加速亚原子粒子（电子和离子），导致加热到数百万度，还可能导致磁化等离子体被驱逐到太空中，这可能导致破坏性的“太空天气”。耀斑具有独特的辐射特征，这些特征与磁场的结构密切相关，也与能量沿着磁场从日冕向下传递到太阳表面并进入遥远的日球层，并在传递过程中转化为其他形式的方式密切相关。通过解释这种辐射，我们可以了解耀斑中发生了什么。更普遍的是，太阳磁场在太阳大气中创造了偏心和动态的形状，例如旋转的“龙卷风”结构，其中等离子体，也许是支持它的磁场，正在旋转。我们的计划将观测数据与理论和数值建模相结合，以解决所有这些主题，并涵盖广泛的天文和技术问题，从等离子体辐射路径的建模到高能粒子加速；从电磁波到相对论粒子束；从图像处理到微弱信号的统计分析，从数学“纸笔”计算到高级数值模拟。我们将运用所有这些技巧来解决当前努力的核心问题，以更好地了解我们最近的恒星。我们工作的某些方面还将帮助我们评估太阳爆发的潜在威胁，这是空间天气预报的关键因素。

The physics of plasmas - particularly plasmas permeated by a magnetic field - dictates the behaviour of much of the visible universe. Close at hand, we need to understand and measure plasmas, fields and particles understand the dynamic Sun and its interaction with the heliosphere. In this proposal we focus on several key unsolved problems in solar physics that are also prototypes for a wider and deeper understanding of cosmic plasmas as a whole. Our top-level questions are: how do high-energy radiating particles behave in solar flares and in interplanetary space? How are they accelerated, are they beamed and do they play a key role in flares and their terrestrial impact? How does the Sun store and release energy in its magnetised atmosphere, and what can we learn about this process by computer simulations and by studying the radiation that is emitted? The magnetic field is key to everything that happens in the Sun's atmosphere. Concentrated magnetic regions emerge through the Sun's surface and into its atmosphere. Here they interact with the pre-existing magnetic field and the result is intense bursts of energy known as flares, which accelerate sub-atomic particles (electrons and ions), cause heating to millions of degrees, and can also lead to expulsion of magnetised plasma into space, which can lead to damaging `space weather'. Flares have distinctive radiation signatures that are closely related to the structure of the magnetic field, and to the way that energy is transmitted along the magnetic field from the corona down to the solar surface and out into the distant heliosphere, and converted into other forms as it goes. By interpreting this radiation we can understand what is happening in a flare. More generally solar magnetic fields create eccentric and dynamic shapes in the solar atmosphere, for example swirling `tornado-like' structures in which the plasma, and perhaps the magnetic field supporting it, is rotating.Our programme combines observational data with theoretical and numerical modelling to address all of these topics, and spans a wide range of astronomical and technical problems, from the modeling of the path of radiation in a plasma to high-energy particle acceleration; from electromagnetic waves to relativistic particle beams; from image processing to statistical analysis of weak signals, and from mathematical `pen-and-paper' calculations to advanced numerical simulations. We will bring all these skills to bear on questions at the heart of current efforts to better understand our nearest star. Some aspects of our work will also help us to assess the potential threat of eruptions on the Sun, which is a key element of space weather forecasting.