Langmuir emitting probe for plasma space potential diagnosing

Abstract

The invention discloses a Langmuir emitting probe for plasma space potential diagnosing. The Langmuir emitting probe comprises a probe body and a probe support. The probe body is made of a 2% thoriated tungsten wire 0.1 in diameter. The thoriated tungsten wire is bent into a U shape. The tail of the thoriated tungsten wire is welded with a copper conductor. The tail of the copper conductor welded with the central signal line of a shielding coaxial cable. The central signal line of the shielding coaxial cable serves as a signal transmission line. Multiple layers of insulation and thermal insulation protective materials wrap the central signal line of the shielding coaxial cable. The probe body is supported by the tubular probe support which is bent into an L shape. The probe support is connected to a spatial positioning device in a threaded manner. The Langmuir emitting probe is small in size, high in signal to noise ratio of signal transmission, high in heat resistance, good in stability, convenient in spatial positioning, small in repeated positioning error, suitable for fast and accurate measuring of plasma feature parameter spatial distribution under various plasma environments, and widely applicable to plasma scientific research and industrial application.

Description

technical field [0001] The invention belongs to the technical field of plasma diagnosis, and relates to a contact diagnosis method, specifically, a Langmuir emission probe used for plasma space potential diagnosis, which can not only be applied in cold plasma, such as glow Discharge plasma, corona discharge plasma, etc.; especially suitable for thermal plasma, such as arc plasma, combustion plasma, etc. Background technique [0002] Plasma is the fourth state of matter, which is a state of matter mainly composed of free electrons and charged ions. According to plasma temperature, plasma is divided into: [0003] (1) High-temperature plasma: plasma with complete ionization, extremely high electron temperature and gas temperature, such as the sun, controlled thermonuclear fusion plasma, etc. [0004] (2) Low-temperature plasma: Plasma with partial ionization and high electron temperature can be divided into the following two categories: [0005] a. Thermal plasma: plasma wi...

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Problems solved by technology

[0014] Existing Langmuir emission probes such as figure 2 As shown: (1) The front end of the head is not sealed, and the charged particles in the plasma will enter the copper wire along the front gap, which will bring errors to the measurement results; (2) the contact between the front end tungsten wire and the copper wire uses a contact Contact method is not as strong and reliable as welding method

If there is a virtual point contact during the experiment, it will cause heat to concentrate at the connection between the two and burn the probe, thus causing the failure of the transmitting probe; (3) the copper wire is not connected to the coaxial cable subsequently, and the subsequent signal transmission Performance and signal-to-noise ratio are low; (4) The copper wire is not coated with heat protection material, which reduces the life of the emission probe

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