Congratulations Felicity Maiden!
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Please join us in congratulating Felicity on passing her Viva. Well done Felicity!
Here is a snippit from her project which was a collaboration between the University of York, UKAEA and Tokamak Energy. She worked under the supervision of Roddy Vann, Simon Freethy, Vladimir Shevchenko and Erasmus du Toit
The project involved a theoretical study of the current drive mechanisms involved in solenoid-free microwave start-up. Solenoid-free start-up is advantageous for tokamak power plants, particularly spherical tokamaks which have limited space in the centre column for a shielded solenoid. Solenoid-free microwave start-up has been demonstrated experimentally and several mechanisms for the current drive have been proposed but some experimental observations remain unexplained. This project studied the solenoid-free microwave experiments previously executed on MAST and proposed a new mechanism for the negative current drive above the midplane in the open field line phase. A new mechanisms for the quasi-closed flux surface phase has also been proposed where a feedback loop between the ramping vertical field and the electron losses maintains an optimal confinement for current drive. These mechanisms were found to be significant when compared to mechanisms proposed in the literature. These results can be used in the design of future experiments and power plants.