Solar coronal heating through magnetic reconnection

Lead Research Organisation: University of Manchester
Department Name: Physics and Astronomy

Abstract

The overall aim of the project is to contribute to understanding how the solar flares release energy and accelerate charged particles, by studying the nature of magnetic energy release during magnetic flux tube reconnection. The focus will be on configurations which release stored magnetic energy trhough merger of twisted magnetic flux ropes. Initial work will focus on modelling test partices in 2D forced reconnection, extending previous work to include island (flux rope) merger. In order to achieve this, the evolution of the magnetic field during forced magnetic reconnection events in the corona will be investigated using magnetohydrodynamic simulations. These results will be used in test-particle simulations using the CGA code to determine the mechanisms by which some particle populations in the solar corona are accelerated to high energies. Building on previous work in unstable twisted coronal loops, more complex magnetic field configurations will then be considered, such as multi-thread and multi-loop interactions. There is also scope to extend the test-particle kinetic model to more self consistent kinetic models, as well as looking at possible applications of the modelling to fusion plasmas.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/N504178/1 01/10/2015 31/03/2021
1662280 Studentship ST/N504178/1 21/09/2015 31/03/2019 Max Potter
 
Title GCA code adjustments 
Description Using C code written by Mykola Gordovskyy (University of Manchester) I produced an updated 2D version of a guiding-centre approximation code for simulating the trajectories of particles in MHD fields. This allows for the study of particle acceleration in the magnetic reconnection environments that I have simulated previously. Multiple bugs were fixed as well as some issues with the assumptions made in the model. The code now correctly interfaces with a proprietory data format produced by the MHD simulation suite I use. 
Type Of Material Improvements to research infrastructure 
Year Produced 2016 
Provided To Others? No  
Impact The code now behaves correctly in cases where drift velocities are large, which is relevant to cases of coronal magnetic reconnection where curvature can be extreme. It also interfaces with previous MHD simulations, which was not previously possible. This allows for a chain of research, from the inception of a model of reconnection, to simulating the fields to understanding how those fields affect populations of particles. This will result in a series of papers. 
 
Title MHD visualisation package 
Description A pipeline now exists to produce large numbers of high quality plots with relative ease using Python. 
Type Of Material Improvements to research infrastructure 
Year Produced 2018 
Provided To Others? No  
Impact Previously plotting was done with IDL code which performed roughly 100 times slower than the new Python code and produced worse results. Control over the format of the plots was highly limited and is now almost limitless. This has been an immense improvement to my workflow, without which my current draft paper would not be possible. 
 
Title MHD studies of forced magnetic reconnection 
Description A collection of MHD simulations which form the basis of my first paper (in draft as of February 2018). These were performed with Lare2d and are based on the model of forced magnetic reconnection first considered by Hahm & Kulsrud. Here, the model has been studied in cases of sinusoidal perturbations, combinations of sinusoidal perturbations and localised (Gaussian) perturbations. In this way we build from the analytical model previously studies up to more realistic cases in the coronal environment, as well as studying the non-linear interaction between multiple perturbations. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? No  
Impact I have written a draft paper and presented the results at several conferences. 
 
Description Filament Reconnection in Tokamaks 
Organisation EURATOM/CCFE Fusion Association
Country United Kingdom 
Sector Academic/University 
PI Contribution I'm working on Hall-MHD simulations of filament reconnection in tokamaks, based on previous work from my department on merging compression in tokamaks. The overall goal is a better understanding of filament reconnection, particularly with respect to ELM instabilities, in tokamaks. I have presented related work in solar flares at a group collaboration meeting last November.
Collaborator Contribution A literature review has been completed, simulation benchmarks have been assessed between different codes and models for future simulations have been proposed.
Impact None yet, other than internal goals.
Start Year 2017
 
Description Bluedot Festival 2017 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Around 800 people attended Bluedot Festival, a music and science festival hosted at the Jodrell Bank radio observatory in Manchester. I was part of a team of postgraduates and undergraduates manning demonstration stalls. My role was to demonstrate use of the solar telescopes and answer any questions people had about sun spots and solar astronomy. I also hosted a stage discussing the work of SETI and astrobiology.
Year(s) Of Engagement Activity 2017
URL https://www.discoverthebluedot.com/
 
Description EGU Vienna 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact I visted the EGU conference in Vienna last year, where I gave a talk on my work on energetic particles in solar flares to an audience of solar physics peers. This talk was given again two weeks later to another international audience at a summer school in Genoble: http://ipag.osug.fr/~lesurg/plasmas2017/
Year(s) Of Engagement Activity 2017
URL https://www.egu2016.eu/