JET-P(88)59
Determination of the Shear on the q = 1 Surface of the JET Tokamak
The large changes observed in visible light and X-ray emission when an injected pellet of solid D2 crosses the q = 1 surface of the JET tokamak are used to deduce the value of the magnetic shear on the q = 1 surface. Very low values are found and the implications for theories of the sawtooth instability are discussed.