Electron density and temperature in NIO1 RF source operated in oxygen and argon

M. Barbisan, B. Zaniol, M. Cavenago, R. Pasqualotto, G. Serianni, M. Zanini

Research output: Contribution to conferencePaper

1 Citation (Scopus)

Abstract

The NIO1 experiment, built and operated at Consorzio RFX, hosts an RF negative ion source, from which it is possible to produce a beam of maximum 130 mA in H-ions, accelerated up to 60 kV. For the preliminary tests of the extraction system the source has been operated in oxygen, whose high electronegativity allows to reach useful levels of extracted beam current. The efficiency of negative ions extraction is strongly influenced by the electron density and temperature close to the Plasma Grid, i.e. the grid of the acceleration system which faces the source. To support the tests, these parameters have been measured by means of the Optical Emission Spectroscopy diagnostic. This technique has involved the use of an oxygen-argon mixture to produce the plasma in the source. The intensities of specific Ar I and Ar II lines have been measured along lines of sight close to the Plasma Grid, and have been interpreted with the ADAS package to get the desired information. This work will describe the diagnostic hardware, the analysis method and the measured values of electron density and temperature, as function of the main source parameters (RF power, pressure, bias voltage and magnetic filter field). The main results show that not only electron density but also electron temperature increase with RF power; both decrease with increasing magnetic filter field. Variations of source pressure and plasma grid bias voltage appear to affect only electron temperature and electron density, respectively.
Original languageEnglish
DOIs
Publication statusPublished - 9 Aug 2017
Externally publishedYes
Event5th International Symposium on Negative Ions, Beams and Sources, NIBS 2016 - Oxford, United Kingdom
Duration: 9 Aug 2017 → …

Conference

Conference5th International Symposium on Negative Ions, Beams and Sources, NIBS 2016
CountryUnited Kingdom
CityOxford
Period9/8/17 → …

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Barbisan, M., Zaniol, B., Cavenago, M., Pasqualotto, R., Serianni, G., & Zanini, M. (2017). Electron density and temperature in NIO1 RF source operated in oxygen and argon. Paper presented at 5th International Symposium on Negative Ions, Beams and Sources, NIBS 2016, Oxford, United Kingdom. https://doi.org/10.1063/1.4995751