DEVELOPMENT AND TESTING OF A SYSTEM DIAGNOSTIC BASED ON A TRIPLE LANGMUIR PROBE IN A PLASMA-BEAM INSTALLATION

The paper presents the development of a triple probe consisting of three tungsten electrodes with a diameter of 1 mm, intended for applications on a plasma beam installation (PBI). The appropriate measuring equipment and electrical wiring diagram have been selected. The probe has successfully passed the commissioning tests, during which key factors were identified that are important for accurate interpretation of the results and integration into the diagnostic system of the PBI. Experimental measurements of plasma parameters using a triple probe showed comparable results with a single probe: the electron temperature was 7 eV, and the plasma concentration was – 10¹⁶ m⁻³. The experimental results obtained confirm the correct operation of the developed probe and its use in experiments due to the simplicity of data processing compared with other types of probes.

1. https://www.iter.org/proj/inafewlines.

2. Patent RK No. 2080. Imitatsionnyy stend s plazmennopuchkovoy ustanovkoy / Kolodeshnikov A.A., Zuev V.A., Ganovichev D.A., Tulenbergenov T.R. [i dr.]; zayavitel' i patentoobladatel' RGP NYaTs RK. – No. 2016/0108.2; zayavl. 29.02.2016; opubl. 15.03.2017, Byul. No. 5.– 3 p. (In Russ.)]

3. Chektybayev B.Zh., Skakov M.K., Tulenbergenov T.R., Sokolov I.A., Miniyazov A.Zh., Zhanbolatova G.K., Nauryzbayev R.Zh. Measurement of plasma parameters in the PBI using the Langmuir probe // Fusion Engineering and Design .–2024.– Vol. 205.– P. 114546. https://doi.org/10.1016/j.fusengdes.2024.114546

4. Bhattarai Sh., Nath Mishra L. Theoretical Study of Spherical Langmuir Probe in Maxwellian Plasma // International Journal of Physics. – 2017. –Vol. 5(3). –P. 73–81. https://doi.org/10.12691/ijp-5-3-2.

5. Godyak V.A., Piejak R.B., Alexandrovich B.M. Measurement of electron energy distribution in lowpressure RF discharges // Plasma Sources Science and Technology. – 1992. –Vol. 1. –P. 36. – https://doi.org/10.1088/0963-0252/1/1/006

6. Crowley B., Dietrich S.A. Langmuir probe system incorporating the Boyd–Twiddy method for EEDF measurement applied to an inductively coupled plasma source // Plasma Sources Science and Technology. – 2009. – Vol. 18. – P. 014010. https://doi.org/10.1088/0963-0252/18/1/014010

7. Chen F.F. Langmuir probes in RF plasma: surprising validity of OML theory // Plasma Sources Science and Technology. – 2009. –Vol. 18. – P. 035012. https://doi.org/10.1088/0963-0252/18/3/035012

8. Bang J.Y., Chung C.W., 2010 Phys. Plasmas

9. Merlino R.L. Understanding Langmuir probe currentvoltage characteristics // American Association of Physics Teachers. – 2007. – Vol. 75. – P. 1078.

10. Ovsyannikov A.A. Zhukov M.F. Plasma diagnostics. – Cambridge International Science Publishing: Cambridge, UK, 2000.

11. Buchenauer D., Hsu W. L., Smith J. P., Hill D.N. Langmuir Probe Array for the DiiiD Divertor // Review of Scientific Instruments. – 1990. –Vol. 61. – P. 2873. https://doi.org/10.1063/1.1141811

12. Asakura N., Shimizu K., Hosogane N., Itami K., Tsuji S., Shimada M.Recycling Enhancement with ne and QEff in High-Density Discharges on Jt-60u // Nuclear Fusion. – 1995. – Vol. 35. – P. 381

13. Xu J. C. et al. Upgrade of Langmuir probe diagnostic in ITER-like tungsten mono-block divertor on experimental advanced superconducting tokamak // Review of Scientific Instruments. –2016. – Vol. 87. – P. 083504. https://doi.org/10.1063/1.4960181

14. Ming T. F. et al. Improvement of divertor triple probe system and its measurements under full graphite wall on EAST // Fusion Engineering and Design. – 2009. – Vol. 84. – P. 57. https://doi.org/10.1016/j.fusengdes.2008.10.005

15. Bak J. G., Lee S.G., Kim J.Y. Electrical Probe Diagnostics for KSTAR // Contributions to Plasma Physics . –2010. – Vol. 50. –P. 892. https://doi.org/10.1002/ctpp.201010151

16. Hammond K. C. et al. Drift effects on W7-X divertor heat and particle fluxes // Plasma Physics and Controlled Fusion. – 2019. – Vol. 61. – P. 125001. https://doi.org/10.1088/1361-6587/ab4825

17. Pandey S., Carls A. Pop-up Langmuir probe diagnostic in the water cooled divertor of Wendelstein 7-X // Review of Scientific Instruments. – 2024. – Vol. 95(4). –P. 043503. https://doi.org/10.1063/5.0188738

18. Tulenbergenov T.R., Sokolov I.A., Miniyazov A.Zh., Kayyrdy G.K., Sitnikov A. A. The linear accelerators review // NNC RK Bulletin. – 2019. Issue 4. – P. 59–67. (In Russ.)]. https://doi.org/10.52676/1729-78852019-4-59-67

19. Jang S. H., Kim G. H., Chung C. W. In situ method for real time measurement of dielectric film thickness in plasmas // J. Appl. Phys.– 2010. – Vol. 107.–P. 023303.

20. Sobolewski M. A. Measuring the ion current in highdensity plasmas using radio-frequency current and voltage measurements // J. Appl. Phys. –2001. – V. 90. – P. 2660– 2671.

21. Mehs D. M., Niemczyk T. M. Plasma models applicable to low pressure discharges // Spectrochim. Acta. Pt B. – 1981. – Vol. 36. – P. 965–971.

22. Rayzer Yu.P. Fizika gazovogo razryada. – Dolgoprudnyy: Intellekt, 2009. (In Russ.)]

23. Qayyum A., Ahmad N., Ahmad S., Deeba F., Ali R., Hussain S. Time-resolved measurement of plasma parameters by means of triple probe // Review of Scientific Instruments. – 2013. – Vol. 84. – P. 123502. https://doi.org/10.1063/1.4838658.

24. Naz M.Y. Ghaffar A. Double and triple Langmuir probes measurements in inductively coupled nitrogen plasma // Progress In Electromagnetics Research . – 2011. – Vol. 114. https://doi.org/10.2528/PIER10110309.

25. Chen Sin-Li., Sekiguchi T. Instantaneous Direct-Display System of Plasma Parameters by Means of Triple Probe // Journal of Applied Physics. – 1965. – Vol. 36. – № 8. https://doi.org/10.1063/1.1714492

26. Bondarenko D. et al. Engineering design of plasma generation devices using Elmer finite element simulation methods // Engineering Science and Technology. – 2016. https://doi.org/10.1016/j.jestch.2016.07.015

27. Roussel R., Andonian G., Hansel C., Lawler G., Lynn W., Majernik N., Robles R., Sanwalka K., Wisniewski E., Rosenzweig J. Externally Heated Hollow Cathode Arc Plasma Source for Experiments in Plasma Wakefield Acceleration // Instruments . – 2019. – Vol. 3. – P. 48.

28. Amrollahi R., Mirzaei H.R., Ghasemi M. Optimizing the Plasma startup through ECR plasma pre-ionization in Taban Tokamak via Triple Langmuir probe // Fusion Engineering and Design. – 2020. – Vol. 150. – P. 111362. https://doi.org/10.1016/j.fusengdes.2019.111362

29. Qin Y. Improved treatment of triple-probe data for determination of electron temperature // Review of Scientific Instruments. – 2005. – Vol. 76(11). – P. 116102. https://doi.org/10.1063/1.2130935

30. Yong-ik S., Lim H. B., Houk R. S. Diagnostic studies of low-pressure inductively coupled plasma in argon using a double Langmuir probe // J. Analyt. Atom. Spectrometry. – 2002. – Vol. 17. – P. 565–569.

31. Itagaki N., Iwata S., Muta K., et al. Electron-temperature dependence of nitrogen dissociation in 915 MHz ECR plasma // Thin Solid Films. – 2003. –Vol. 435. – P. 259– 263.