A multichannel microwave reflectometer system is used to measure the electron density profile at JET. A new measurement technique is described which gives continuous information on the electron profile in time. Profile measurements using swept-frequency measurements are combined with accurate measurements of the evolution of the density using fixed-frequency operation. The analysis of the data can be carried out routinely for each discharge at JET. The method includes estimates for the uncertainties on the measurements, corrections for finite sweep on the data and relativistic effects. The results compare well with other measurements of the electron density in JET.
Implementation of real-time reflectometry for electronic density profile reconstruction on the WEST tokamak