The first measurement of plasma density in an ECRIS-like device by means of a frequency-sweep microwave interferometer

The note presents the first plasma density measurements collected by a novel microwave interferometer in a compact Electron Cyclotron Resonance Ion Sources (ECRIS). The developed K-band (18.5 divided by 26.5 GHz) microwave interferometry, based on the Frequency-Modulated Continuous-Wave method, has been able to discriminate the plasma signal from the spurious components due to the reflections at the plasma chamber walls, when working in the extreme unfavorable condition lambda(p) similar or equal to L-p similar or equal to L-c (lambda(p), L-p, and L-c being the probing signal wavelength, the plasma dimension and the plasma chamber length, respectively). The note describes the experimental procedure when probing a high density plasma (n(e) > 1 . 10(18) cm(-3)) produced by an ECRIS prototype operating at 3.75 GHz. Published by AIP Publishing.