Plasma electron density measuring device

Abstract

The invention discloses a plasma electron density measuring device which comprises a first terahertz solid source, a second terahertz solid source, an interferometer light path and the like. The interferometer light path is used for outputting a light beam generated by the first solid source to the first detector; the laser is also used for outputting the light beam generated by the first solid source to the second detector; the interferometer light path is used for outputting a light beam generated by the second solid source to the first detector; the second detector is also used for outputting the light beam generated by the second solid source to the corner reflector passing through the plasma, so that the second detector receives the light beam returned by the corner reflector; the first detector and the second detector are used for obtaining a combined beam signal, so that the device calculates the plasma electron density according to the combined beam signal. The plasma electron density measuring device provided by the embodiment of the invention has the advantages of compact layout, fewer used optical devices, no need of using a large-scale bracket, convenience in design and installation on a large-scale plasma experimental device, stable operation and low operation and maintenance cost.

Description

technical field [0001] The invention relates to the field of optical technology, in particular to a plasma electron density measuring device. Background technique [0002] In the magnetic confinement fusion experimental device and the space plasma experimental simulation and research device, the plasma electron density is a crucial physical parameter. Almost all experimental devices require the ability to accurately and quickly measure the plasma in the experimental research of plasma physics. electron density. [0003] In the prior art, the light source in the far-infrared band is suitable for tokamak fusion experimental devices, and is the most applicable light source in interferometer systems at home and abroad. Gas lasers, as described in the article "Xu Qiang et al. 2008 Plasma Sci. Technol. 10 519", the HCN interferometer system developed on the EAST tokamak experimental setup, uses an HCN laser with a cavity length of 3 meters, The laser is an electrically excited g...

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Problems solved by technology

[0003] In the prior art, the light source in the far-infrared band is suitable for tokamak fusion experimental devices, and it is the most suitable light source in interferometer systems at home and abroad. However, the light source in this band has been used in the past with large volume and low output stability. Gas laser, as described in the article "Xu Qiang et al.2008Plasma Sci.Technol.10 519", the HCN interferometer system developed on the EAST tokamak experimental device, using the HCN laser with a cavity length of 3 meters, The laser is an electrically excited gas laser, which uses a rotating grating to modulate the difference frequency signal. The entire laser system is large in size and needs to occupy a large area of ​​experimental space. The power output of the laser is unstable, and it is necessary to continuously adjust the power output during operation, and The difference frequency of the rotating grating modulation is low, so that the time resolution of the entire interferometer is low; as described in the article "H Q Liu et al.2013JINST 8C11002", 11-channel polarization interference was developed on the EAST tokamak experimental device Instrument system, the system uses 3 imported carbon dioxide pumped formic acid lasers as light sources, the power output of the light source is relatively stable, using the principle of dual lasers, the difference frequency can reach the order of megahertz, and the time resolution is also high, but the whole The laser system needs to build a large-area laser clean room with constant temperature and humidity and vibration reduction effects, and the system uses the principle of dual lasers for difference frequency output. The difference frequency output also needs to be adjusted by the staff at any time during the experiment, which increases the Operating costs

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