343 



JET Diagnostics 



To find out whal is happening within the Much of the equipment for operating 



plasma, a number of measuring these systems is situated outside the 



systems are used These systems. Torus Hall to allow easy access to t 



called diagnostics, are used to obtain mstrunrtentation dunng machine 



experimental data from the plasma operation 



JET Power Supplies 



The peak eleclncal power required (or each JET pulse 

 exceeds 700 MW and because there is a limit to the powe 

 which may be drawn directly from the grid, two flywheel 

 generators are used as a means of storing energy 

 Each of the flywheel generators consists of a 9 

 diameter rotor weighing 775 tonnes Between each pulse 

 the flywheels are increased to lull speed of 225 rpm by 

 8.8 MW motors When power is needed lor a JET pulse the 

 rotor windings are energised and the rotational energy is 

 converted into electrical energy causing the rotors to slow 

 down to about half speed 



The generators are each capable of delivering 400 MW of 

 pulsed power 



