Measurement of Shafranov shift with soft x-ray CCD camera on large helical device

The Shafranov shift is derived from the two-dimensional profile of x-ray intensity measured with a soft x-ray CCD camera in large helical device. The accuracy of the measurement of the magnetic axis is 3% of the Shafranov shift at high β. The measured Shafranov shift increases linearly up to 280±3 mm, which is 47% of the minor radius as the volume averaged β<βdia> measured with a diamagnetic loop is increased up to 2.6%. The Shafranov shift measured with a soft x-ray CCD camera agrees with that calculated with the three-dimensional equilibrium code VMEC. The reduction of the Shafranov shift due to the higher harmonics of the Fourier components of the magnetic field is also observed. (author)