Mathias Hoppe, Physics and Astronomy
Title of Master's thesis: A synthetic synchrotron diagnostic for runaway electrons in tokamaks
Abstract of thesis
Magnetic confinement fusion is one of the best options for cheap and long-term sustainable energy production in the future, and of the various magnetic fusion devices currently being investigated the tokamak is the most promising candidate. Despite being crucial to bringing commercial fusion closer to reality than ever before over the past decades, the tokamak suffers a number of drawbacks. One of the more urgent issues that must be addressed is the generation of the highly relativistic electrons known as "runaway electrons" which can escape confinement and collide with the tokamak wall, potentially causing severe damage to the device and critically decreasing the lifetime of wall components. In the ITER tokamak - the flagship of international fusion research currently under construction in Cadarache, France - the successful mitigation of runaway electrons will be crucial to the success of the entire project, something which requires a solid understanding of the processes involving runaway electrons.
One of the most common ways for studying runaway electrons in experiment is to measure the spectrum and making images of the synchrotron radiation emitted by them. In this project the synthetic synchrotron diagnostic SOFT was developed to model the synchrotron cameras used in experiment and to simulate the synchrotron images resulting from runaway electron synchrotron emission. The angular- and spectral distribution of synchrotron radiation is derived from first-principles, and by utilizing characteristic properties of synchrotron radiation a simplified model can be derived. Using SOFT, the dependence of a synchrotron image on the electron energy, pitch angle, radial distribution and camera location is investigated, allowing general conclusions about the synchrotron image due to a population of runaway electrons to be drawn.
Supervisor: Ola Embreus
Examiner: Tünde Fülöp
Opponent: Ingrid Strandberg
Student project presentation
N6115 seminar room, Origo building 6th floor, Fysikgården 1
12 May, 2017, 10:00
12 May, 2017, 11:00