How to operate a tokamak

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Shoot magnetic islands: a screen shot of 'Operation Tokamak'

The new app 'Operation Tokamak' invites gamers to have a go at realising fusion power.

Being the operator of a fusion machine, players have to control the plasma by shaping the magnetic field, bring up the heat with the help of powerful microwaves and blast harmful magnetic islands away.



It goes without saying that the script of a game has different requirements than a fusion device. Therefore some simplifications were necessary to develop the gameplay of ‘Operation Tokamak’. Despite that the motivation of this game has been to give the player a sense of the essential requirements that make fusion happen. The biggest difference between the game and reality is certainly that in ‘Operation Tokamak’ fusion energy is produced regularly and widely in many countries. In reality about 40 fusion laboratories do research on how this goal can be achieved.

Operation Tokamak in the control room


In a real control room there is more than one actor to run an experiment which is carefully planned in advanced. For a start, there are two main players working hand in hand: The Session Leader and the Engineer-in-Charge. The Session Leader is in charge of the scientific aims of the experiment while the Engineer-in-Charge makes sure that the systems are functioning properly and are used safely – he or she will hit the stop button if the scientists are getting too creative.


The Session Leaders’ job starts some days ahead of their duty in the control room: They design the plasma pulses to achieve the experimental goals as defined by the Scientific Coordinator. This means setting the plasma parameters such as magnetic field, plasma current, or gas, planning the sequence of steps from the start through to the end of the pulse and defining the required heating power. Together with the Additional Heating Pilots, the Session Leader discusses the best strategy for when and how to apply the heating systems – for instance, the powerful microwave systems also featured in ‘Operation Tokamak’. The Diagnostic Coordinators request all the measurement systems that are necessary to monitor the plasma and to record the experimental data.


picture of JET control room

In the JET control room (Picture taken in 2011 showing scientists follow the first plasma attempt with JET’s new ITER-Like-Wall)

The countdown begins


To begin a plasma pulse, the Power Supply Engineer starts JET’s two flywheel generators to build up hundreds of megawatts of power. Two nine meter wide steel wheels are set into a horizontal rotation and reach 225 rounds per minute – a spinning rate at which their edges rotate at a speed of 380 km/h. At the same time, The CODAS Duty Officers make sure that the computers and software are ready. A two and a half minute long countdown begins, urging all coordinators to ensure that their systems are ready. Once that is confirmed, the Engineer in Charge starts the pulse and the experiment is on. The magnetic field builds up. The heating pilots make sure that the microwave and particle beam systems to heat the plasma function correctly. The diagnostic coordinators monitor their systems to ensure the best quality of the experimental data.

Sorry, no shooting of instabilities in the control room

And the magnetic islands which players blast away in the game? Fusion scientists investigate various ways to mitigate these plasma instabilities. One of them is an automated feedback system. It picks up the magnetic islands thanks to their emission of tiny amounts of microwaves, automatically directs powerful microwaves at their spot and shrinks them to harmless size. Just like the players in ‘Operation Tokamak’.


You find lots of general and more in-depth information on our website to get a better understanding of the real science is pursued in a mutual European effort. Find out more about fusion conditions here.


But you are already prepared to run your own session in the ‘Operation Tokamak’ game. Find out how much energy you produced and how much CO2 you saved. And do not forget to share your score with your friends on your private Facebook account. Tweet about it using #optok. Good luck!