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format: markdown
title: Plasma position measurement and use of vertical stabilization 
...


#**Motivation**

Why do we want to measure the position of the plasma? Because we can (or we can try it at least) and also the knowledge of plasma position is necessary almost for interpretation of all experiments. As you will see, the plasma tends to move upwards in Golem tokamak, which ends with premature termination of a discharge. Appropriate usage of vertical stabilization can prolong the discharge and also improve the plasma performance.    


#**Tasks**

* Understand the principles of magnetic diagnostics  
* Learn about magnetic diagnostics used in tokamaks
* Learn digital data processing routines for determination of plasma position
    * Calculate the plasma position by different algorithms and compare results 
* Process magnetic data from various shots and compare determine plasma position with output from different diagnostics (fast camera, bolometers, etc.)
* Perform experiments with vertical stabilization on tokamak Golem
    * Try to move with the plasma or prolong duration of discharge 


#**Resources**

* J. Wesson: Tokamaks, Third edition, Oxford University Press, Clarendon Press, Oxford, 2004 (pages 108 – 120)
* J. P. Freidberg: Ideal Magnetohydrodynamics, Plenum Press, New York 1987 (pages 108 – 122)
* V.S. Mukhovatov, V.D. Shafranov: Plasma Equilibrium in a Tokamak, Nuclear Fusion 11, 605 (1971) (the best of them)
* [Plasma position at Golem](http://golem.fjfi.cvut.cz/wiki/Diagnostics/Magnetic/MirnovCoilsAtLimiter/Theory/plasma_position)
* [Mirnov Coil at Golem](http://golem.fjfi.cvut.cz/wiki/Diagnostics/Magnetic/MirnovCoilsAtLimiter/Theory/diagnostics_mirnov)
* [Magnetic field configurations and their measurement on tokamak GOLEM](https://physics.fjfi.cvut.cz/publications/FTTF/BP_Tomas_Markovic.pdf)
* [Measurement and Analysis of Magnetic Fields of the Tokamak GOLEM](https://physics.fjfi.cvut.cz/publications/FTTF/VU_Tomas_Markovic.pdf)
* [Measurement of Magnetic Fields on GOLEM Tokamak](https://physics.fjfi.cvut.cz/publications/FTTF/DP_Tomas_Markovic.pdf)

--------------------- in Czech only (still useful for figures :-)) ---------------------

* [Zpětnovazební řízení polohy na tokamaku GOLEM](https://physics.fjfi.cvut.cz/publications/FTTF/BP_Jindrich_Kocman.pdf)
* [Zpětnovazební řízení polohy plazmatu na tokamaku GOLEM](https://physics.fjfi.cvut.cz/publications/FTTF/VU_Jindrich_Kocman.pdf)
* [Řízení polohy plazmatického prstence na tokamaku GOLEM](https://physics.fjfi.cvut.cz/publications/FTTF/DP_Jindrich_Kocman.pdf)