Electron density measurements of a field-reversed configuration plasma using a novel compact ultrastable second-harmonic interferometer.
A compact high-sensitivity second-harmonic interferometer for line-integrated electron density measurements on a large plasma machine is presented. The device is based on a fiber coupled near-infrared continuous-wave Nd:YAG laser and is remotely controlled. The performances of the instrument are tested on the Irvine field-reversed configuration machine, and a sensitivity of few 10(14) cm(-2) in measuring line integrated electron density is demonstrated with a time resolution of a few microseconds. The interferometer is self calibrated, has an impressive stability, and it does not require any further alignment after proper installation. These features make this device a real turn-key system suitable for electron density measurement in large plasma machines.
Brandi
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Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa, Italy. fernando.brandi@iit.it
Giammanco
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Harris
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Roche
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Trask
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Wessel
F J
FJ