Ball-pen probe

Last updated
Ball-pen probe used on tokamak CASTOR in 2004. A stainless steel collector moves inside a ceramic (boron nitride) shielding tube. BPP probe head.png
Ball-pen probe used on tokamak CASTOR in 2004. A stainless steel collector moves inside a ceramic (boron nitride) shielding tube.
Schematic picture of a single ball-pen probe. Ions (in red) have a large gyromagnetic radius and can reach the collector more easily than electrons (in blue). Ball-pen probe schematic.png
Schematic picture of a single ball-pen probe. Ions (in red) have a large gyromagnetic radius and can reach the collector more easily than electrons (in blue).

A ball-pen probe [1] is a modified Langmuir probe used to measure the plasma potential [2] in magnetized plasmas. The ball-pen probe balances the electron and ion saturation currents, so that its floating potential is equal to the plasma potential. Because electrons have a much smaller gyroradius than ions, a moving ceramic shield can be used to screen off an adjustable part of the electron current from the probe collector.

Contents

Ball-pen probes are used in plasma physics, notably in tokamaks such as CASTOR, (Czech Academy of Sciences Torus) [1] [2] [3] ASDEX Upgrade, [4] [5] [6] [7] [8] [9] [10] COMPASS, [6] [7] [11] [12] [13] [14] [10] [15] [16] [17] [1] ISTTOK, [10] [18] MAST, [19] [20] TJ-K, [21] [22] RFX, [23] H-1 Heliac, [24] [25] IR-T1, [26] [27] [28] GOLEM [29] as well as low temperature devices as DC cylindrical magnetron in Prague [21] [30] [31] [32] [33] and linear magnetized plasma devices in Nancy [34] [35] and Ljubljana. [21] [30] [36] [ excessive citations ]

Principle

If a Langmuir probe (electrode) is inserted into a plasma, its potential is not equal to the plasma potential because a Debye sheath forms, but instead to a floating potential . The difference with the plasma potential is given by the electron temperature :

where the coefficient is given by the ratio of the electron and ion saturation current density ( and ) and collecting areas for electrons and ions ( and ):

The ball-pen probe modifies the collecting areas for electrons and ions in such a way that the ratio is equal to one. Consequently, and the floating potential of the ball-pen probe becomes equal to the plasma potential regardless of the electron temperature:

Design and calibration

Potential and ln(R) of the ball-pen probe for different positions of the collector. Vfl lnIsat Ball-pen probe 80mm.png
Potential and ln(R) of the ball-pen probe for different positions of the collector.

A ball-pen probe consists of a conically shaped collector (non-magnetic stainless steel, tungsten, copper, molybdenum), which is shielded by an insulating tube (boron nitride, Alumina). The collector is fully shielded and the whole probe head is placed perpendicular to magnetic field lines.

When the collector slides within the shield, the ratio varies, and can be set to 1. The adequate retraction length strongly depends on the magnetic field's value. The collector retraction should be roughly below the ion's Larmor radius.[ citation needed ] Calibrating the proper position of the collector can be done in two different ways:

  1. The ball-pen probe collector is biased by a low-frequency voltage that provides the I-V characteristics and obtain the saturation current of electrons and ions. The collector is then retracted until the I-V characteristics becomes symmetric. In this case, the ratio is close to unity, though not exactly. [1] [5] [37] If the probe is retracted deeper, the I-V characteristics remain symmetric.
  2. The ball-pen probe collector potential is left floating, and the collector is retracted until its potential saturates. The resulting potential is above the Langmuir probe potential. [ clarification needed ]

Electron temperature measurements

Using two measurements of the plasma potential with probes whose coefficient differ, it is possible to retrieve the electron temperature passively (without any input voltage or current). Using a Langmuir probe (with a non-negligible) and a ball-point probe (whose associated is close to zero) the electron temperature is given by:

where is measured by the ball-pen probe, by the standard Langmuir probe, and is given by the Langmuir probe geometry, plasma gas composition, the magnetic field, and other minor factors (secondary electron emission, sheath expansion, etc). It can be calculated theoretically, its value being about 3 for a non-magnetized hydrogen plasma. [38] [39]

In practice, the ratio for the ball-pen probe is not exactly equal to one, [5] so that the coefficient must be corrected by an empirical value for :

where

Related Research Articles

<span class="mw-page-title-main">Tokamak</span> Magnetic confinement device used to produce thermonuclear fusion power

A tokamak is a device which uses a powerful magnetic field to confine plasma in the shape of a torus. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power. As of 2016, it was the leading candidate for a practical fusion reactor. The word "tokamak" is derived from a Russian acronym meaning "toroidal chamber with magnetic coils".

<span class="mw-page-title-main">Plasma stability</span> Degree to which disturbing a plasma system at equilibrium will destabilize it

In plasma physics, plasma stability concerns the stability properties of a plasma in equilibrium and its behavior under small perturbations. The stability of the system determines if the perturbations will grow, oscillate, or be damped out. It is an important consideration in topics such as nuclear fusion and astrophysical plasma.

A Langmuir probe is a device used to determine the electron temperature, electron density, and electric potential of a plasma. It works by inserting one or more electrodes into a plasma, with a constant or time-varying electric potential between the various electrodes or between them and the surrounding vessel. The measured currents and potentials in this system allow the determination of the physical properties of the plasma.

Plasma diagnostics are a pool of methods, instruments, and experimental techniques used to measure properties of a plasma, such as plasma components' density, distribution function over energy (temperature), their spatial profiles and dynamics, which enable to derive plasma parameters.

<span class="mw-page-title-main">Levitated Dipole Experiment</span>

The Levitated Dipole Experiment (LDX) was an experiment investigating the generation of fusion power using the concept of a levitated dipole. The device was the first of its kind to test the levitated dipole concept and was funded by the US Department of Energy. The machine was also part of a collaboration between the MIT Plasma Science and Fusion Center and Columbia University, where another (non-levitated) dipole experiment, the Collisionless Terrella Experiment (CTX), was located.

<span class="mw-page-title-main">Magnetic confinement fusion</span> Approach to controlled thermonuclear fusion using magnetic fields

Magnetic confinement fusion (MCF) is an approach to generate thermonuclear fusion power that uses magnetic fields to confine fusion fuel in the form of a plasma. Magnetic confinement is one of two major branches of controlled fusion research, along with inertial confinement fusion.

The polywell is a proposed design for a fusion reactor using an electric and magnetic field to heat ions to fusion conditions.

An edge-localized mode (ELM) is a plasma instability occurring in the edge region of a tokamak plasma due to periodic relaxations of the edge transport barrier in high-confinement mode. Each ELM burst is associated with expulsion of particles and energy from the confined plasma into the scrape-off layer. This phenomenon was first observed in the ASDEX tokamak in 1981. Diamagnetic effects in the model equations expand the size of the parameter space in which solutions of repeated sawteeth can be recovered compared to a resistive MHD model. An ELM can expel up to 20 percent of the reactor's energy.

<span class="mw-page-title-main">Plasma (physics)</span> State of matter

Plasma is one of four fundamental states of matter characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars, but also dominating the rarefied intracluster medium and intergalactic medium. Plasma can be artificially generated, for example, by heating a neutral gas or subjecting it to a strong electromagnetic field.

The GLAss Spherical Tokamak is a name given to a set of small spherical tokamaks located in Islamabad, Pakistan. They were developed by the Pakistan Atomic Energy Commission (PAEC) as part of the National Tokamak Fusion Program (NTFP) in 2008 and are primarily used for teaching and training purposes.

<span class="mw-page-title-main">COMPASS tokamak</span> Tokamak fusion energy device

COMPASS, short for Compact Assembly, is a compact tokamak fusion energy device originally completed at the Culham Science Centre in 1989, upgraded in 1992, and operated until 2002. It was designed as a flexible research facility dedicated mostly to plasma physics studies in circular and D-shaped plasmas.

<span class="mw-page-title-main">Hybrid Illinois Device for Research and Applications</span> Toroidal magnetic fusion device

The Hybrid Illinois Device for Research and Applications (HIDRA) is a medium-sized toroidal magnetic fusion device housed in the Nuclear Radiation Laboratory and operated by the Center for Plasma-Material Interactions (CPMI) within the Department of Nuclear, Plasma and Radiological Engineering at the University of Illinois at Urbana–Champaign, United States. HIDRA had its first plasma at the end of April 2016 and started experimental campaigns by December of that year. HIDRA is the former WEGA classical stellarator that was operated at the Max Planck Institute for Plasma Physics in Greifswald Germany from 2001 to 2013.

High-confinement mode, or H-mode, is an operating regime possible in toroidal magnetic confinement fusion devices – mostly tokamaks, but also in stellarators. In this regime the plasma has a higher energy confinement time.

Jose A. Boedo is a Spanish plasma physicist and a researcher at University of California, San Diego. He was elected as a fellow of the American Physical Society in 2016 for "his ground-breaking contributions to the studies of plasma drifts and intermittent plasma transport in the peripheral region of tokamaks".

Hartmut Zohm is a German plasma physicist who is known for his work on the ASDEX Upgrade machine. He received the 2014 John Dawson Award and the 2016 Hannes Alfvén Prize for successfully demonstrating that neoclassical tearing modes in tokamaks can be stabilized by electron cyclotron resonance heating, which is an important design consideration for pushing the performance limit of the ITER.

Noah Hershkowitz was an American experimental plasma physicist. He was known for his pioneering research on the understanding of plasma sheaths, solitons and double layers in plasmas, as well as the development of the emissive probe which measures the plasma potential.

Keith Howard Burrell is an American plasma physicist.

Friedrich E. Wagner is a German physicist and emeritus professor who specializes in plasma physics. He was known to have discovered the high-confinement mode of magnetic confinement in fusion plasmas while working at the ASDEX tokamak in 1982. For this discovery and his subsequent contributions to fusion research, was awarded the John Dawson Award in 1987, the Hannes Alfvén Prize in 2007 and the Stern–Gerlach Medal in 2009.

<span class="mw-page-title-main">Tokamak Chauffage Alfvén Brésilien</span> Tokamak at the University of Sao Paulo, Brazil

The Tokamak Chauffage Alfvén Brésilien (TCABR) is a tokamak situated at the University of Sao Paulo (USP), Brazil. TCABR is the largest tokamak in the southern hemisphere and one of the magnetic-confinement devices committed to advancing scientific knowledge in fusion power.

Low to High Confinement Mode Transition, more commonly referred to as L-H transition, is a phenomenon in the fields of plasma physics and magnetic confinement fusion, signifying the transition from less efficient plasma confinement to highly efficient modes. The L-H transition, a milestone in the development of nuclear fusion, enables the confinement of high-temperature plasmas. The transition is dependent on many factors such as density, magnetic field strength, heating method, plasma fueling, and edge plasma control, and is made possible through mechanisms such as edge turbulence, E×B shear, edge electric field, and edge current and plasma flow. Researchers studying this field use tools such as Electron Cyclotron Emission, Thomson Scattering, magnetic diagnostics, and Langmuir probes to gauge the PLH and seek to lower this value. This confinement is a necessary condition for sustaining the fusion reactions, which involve the combination of atomic nuclei, leading to the release of vast amounts of energy.

References

  1. 1 2 3 4 Adámek, J.; J. Stöckel; M. Hron; J. Ryszawy; M. Tichý; R. Schrittwieser; C. Ionită; P. Balan; E. Martines; G. Van Oost (2004). "A novel approach to direct measurement of the plasma potential". Czechoslovak Journal of Physics. 54 (3): 95–99. Bibcode:2004CzJPS..54C..95A. doi:10.1007/BF03166386. ISSN   1572-9486. S2CID   54869196.
  2. 1 2 Adámek, J.; J. Stöckel; I. Ďuran; M. Hron; R. Pánek; M. Tichý; R. Schrittwieser; C. Ionit; P. Balan; E. Martines; G. Oost (2005). "Comparative measurements of the plasma potential with the ball-pen and emissive probes on the CASTOR tokamak". Czechoslovak Journal of Physics. 55 (3): 235–242. Bibcode:2005CzJPh..55..235A. doi:10.1007/s10582-005-0036-8. ISSN   0011-4626. S2CID   54002051.
  3. ↑ J. Adámek, C. Ionita, R. Schrittwieser, J. Stöckel, M. Tichy, G. Van Oost. "Direct Measurements of the Electron Temperature by a Ball-pen/Langmuir probe", 32nd EPS Conference on Plasma Phys. Tarragona, 27 June - 1 July 2005 ECA Vol.29C, P-5.081 (2005)
  4. ↑ Adamek, J.; V. Rohde; H.W. Müller; A. Herrmann; C. Ionita; R. Schrittwieser; F. Mehlmann; J. Stöckel; J. Horacek; J. Brotankova (2009). "Direct measurements of the plasma potential in ELMy H-mode plasma with ball-pen probes on ASDEX Upgrade tokamak". Journal of Nuclear Materials. 390–391: 1114–1117. Bibcode:2009JNuM..390.1114A. doi:10.1016/j.jnucmat.2009.01.286. hdl: 11858/00-001M-0000-0026-F6E0-E .
  5. 1 2 3 Adamek, J.; J. Horacek; H.W. Müller; V. Rohde; C. Ionita; R. Schrittwieser; F. Mehlmann; B. Kurzan; J. Stöckel; R. Dejarnac; V. Weinzettl; J. Seidl; M. Peterka (2010). "Ball-Pen Probe Measurements in L-Mode and H-Mode on ASDEX Upgrade". Contributions to Plasma Physics. 50 (9): 854–859. Bibcode:2010CoPP...50..854A. doi: 10.1002/ctpp.201010145 . S2CID   122712744.
  6. 1 2 Adamek, J.; J. Horacek; J. Seidl; H.W. Müller; R. Schrittwieser; F. Mehlmann; P. Vondracek; S. Ptak (2014). "Direct Plasma Potential Measurements by Ball-Pen Probe and Self-Emitting Langmuir Probe on COMPASS and ASDEX Upgrade". Contributions to Plasma Physics. 54 (4): 279–284. Bibcode:2014CoPP...54..279A. doi:10.1002/ctpp.201410072. S2CID   117937384.
  7. 1 2 J. Adamek, H.W. Müller, J. Horacek, R. Schrittwieser, P. Vondracek, B. Kurzan, P. Bilkova, P. Böhm, M. Aftanas, R. Panek. "Radial profiles of the electron temperature on COMPASS and ASDEX Upgrade from ball-pen probe and Thomson scattering diagnostic", 41st EPS Conference on Plasma Physics, Berlin, P2.011
  8. ↑ Horacek, J.; J. Adamek; H.W. Müller; J. Seidl; C. Ionita; F. Mehlmann; A.H. Nielsen; V. Rohde; E. Havlickova (2010). "Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade". Nuclear Fusion. 50 (10): 105001. Bibcode:2010NucFu..50j5001H. doi:10.1088/0029-5515/50/10/105001. hdl: 11858/00-001M-0000-0026-EFA1-2 . S2CID   123227789.
  9. ↑ Müller, H.W.; J. Adamek; R. Cavazzana; G.D. Conway; C. Fuchs; J.P. Gunn; A. Herrmann; J. Horacek; et al. (2011). "Latest investigations on fluctuations, ELM filaments and turbulent transport in the SOL of ASDEX Upgrade". Nuclear Fusion. 51 (7): 073023. Bibcode:2011NucFu..51g3023M. doi:10.1088/0029-5515/51/7/073023. hdl: 11858/00-001M-0000-0026-EBAB-0 . S2CID   121614262.
  10. 1 2 3 Adamek, J.; H.W. Müller; C. Silva; R. Schrittwieser; C. Ionita; F. Mehlmann; S. Costea; J. Horacek; B. Kurzan; P. Bilkova; P. Böhm; M. Aftanas; P. Vondracek; J. Stöckel; R. Panek; H. Fernandes; H. Figueiredo (2016). "Profile measurements of the electron temperature on the ASDEX Upgrade, COMPASS, and ISTTOK tokamak using Thomson scattering, triple, and ball-pen probes". Review of Scientific Instruments. 87 (4): 043510. Bibcode:2016RScI...87d3510A. doi:10.1063/1.4945797. PMID   27131677.
  11. ↑ J. Seidl, B. Vanovac, J. Adamek, J. Horacek, R. Dejarnac, P. Vondracek, M. Hron "Probe measurement of radial and parallel propagation of ELM filaments in the SOL of the COMPASS tokamak", 41st EPS Conference on Plasma Physics, Berlin, P5.059
  12. ↑ Loureiro, J.; C. Silva; J. Horacek; J. Adamek; J. Stockel (2014). "Scrape-off layer width of parallel heat flux on tokamak COMPASS". Plasma Physics & Technology. 1 (3): 121–123. ISSN   2336-2634.
  13. ↑ J. Adamek, J. Seidl, R. Panek, M. Komm, P. Vondracek, J. Stöckel. "Fast measurements of the electron temperature in divertor region of the COMPASS tokamak using ball-pen probe", 42nd EPS Conference on Plasma Physics, lisbon, P4.101
  14. ↑ Panek, R.; J. Adamek; M. Aftanas; P. Bilkova; P. Böhm; F. Brochard; P. Cahyna; J. Cavalier; R.Dejarnac; M. Dimitrova; O. Grover; J. Harrison; P. Hacek; J. Havlicek; A. Havranek; J. Horacek; M. Hron; M. Imrisek; F. Janky; A. Kirk; M. Komm; K. Kovarik; J. Krbec; L. Kripner; T. Markovic; K. Mitosinkova; J. Mlynar; D. Naydenkova; M. Peterka; J. Seidl; J. Stöckel; E. Stefanikova; M. Tomes; J. Urban; P. Vondracek; M. Varavin; J. Varju; V. Weinzettl; J. Zajac (2016). "Status of the COMPASS tokamak and characterization of the first H-mode". Plasma Phys. Control. Fusion. 58 (1): 014015. Bibcode:2016PPCF...58a4015P. doi: 10.1088/0741-3335/58/1/014015 .
  15. ↑ Grover, O.; J. Adamek; J. Seidl; A. Devitre; M. Sos; P. Vondracek; P. Bilkova; M. Hron (2017). "First simultaneous measurements of Reynolds stress with ball-pen and Langmuir probes". Review of Scientific Instruments. 88 (6): 063501. Bibcode:2017RScI...88f3501G. doi:10.1063/1.4984240. PMID   28668002.
  16. ↑ Adamek, J.; J. Seidl; M. Komm; V. Weinzettl; R. Panek; J. Stöckel; M. Hron; P. Hacek; M. Imrisek; P. Vondracek; J. Horacek; A. Devitre (2017). "Fast measurements of the electron temperature and parallel heat flux in ELMy H-mode on the COMPASS tokamak". Nuclear Fusion. 57 (2): 022010. Bibcode:2017NucFu..57b2010A. doi:10.1088/0029-5515/57/2/022010. S2CID   125525532.
  17. ↑ Adamek, J.; J. Seidl; J. Horacek; M. Komm; T. Eich; R. Panek; J. Cavalier; A. Devitre; M. Peterka; P. Vondracek; J. Stöckel; D. Sestak; O. Grover; P. Bilkova; P. Böhm; J. Varju; A. Havranek; V. Weinzettl; J. Lovell; M. Dimitrova; K. Mitosinkova; R. Dejarnac; M. Hron (2017). "Electron temperature and heat load measurements in the COMPASS divertor using the new system of probes". Nuclear Fusion. 57 (11): 116017. Bibcode:2017NucFu..57k6017A. doi:10.1088/1741-4326/aa7e09. hdl: 11858/00-001M-0000-002D-BA59-3 . S2CID   125143428.
  18. ↑ Silva, C.; J. Adamek; H. Fernandes; H. Figueiredo (2015). "Comparison of fluctuations properties measured by Langmuir and ball-pen probes in the ISTTOK boundary plasma". Plasma Physics and Controlled Fusion. 57 (2): 025003. Bibcode:2015PPCF...57b5003S. CiteSeerX   10.1.1.691.3443 . doi:10.1088/0741-3335/57/2/025003. S2CID   59151012.
  19. ↑ Walkden, N R; J. Adamek; S. Allan; B. D. Dudson; S. Elmore; G. Fishpool; J. Harrison; A. Kirk; M. Komm (2015). "Profile measurements in the plasma edge of MAST using a ball pen probe". Review of Scientific Instruments. 86 (2): 023510. arXiv: 1411.7298 . Bibcode:2015RScI...86b3510W. doi:10.1063/1.4908572. PMID   25725845. S2CID   21518172.
  20. ↑ N. R. Walkden, "Properties of Intermittent Transport in the Mega Ampere Spherical Tokamak", PhD Thesis,
  21. 1 2 3 Adamek, Jiri; Matej Peterka; Tomaz Gyergyek; Pavel Kudrna; Mirko Ramisch; Ulrich Stroth; Jordan Cavalier; Milan Tichy (2013). "Application of the ball-pen probe in two low-temperature magnetised plasma devices and in torsatron TJ-K". Contributions to Plasma Physics. 53 (1): 39–44. Bibcode:2013CoPP...53...39A. doi:10.1002/ctpp.201310007. S2CID   120969312.
  22. ↑ "Plasma Dynamics and Diagnostics | Institute of Interfacial Process Engineering and Plasma Technology | University of Stuttgart". 13 September 2023.
  23. ↑ "Welcome to Consorzio RFX site". Archived from the original on 2009-09-01. Retrieved 2020-06-26.
  24. ↑ Michael, C.A.; F. Zhao; B. Blackwell; M. F. J. Vos; J. Brotankova; S. R. Haskey; B. Seiwald; J. Howard (2017). "Influence of magnetic configuration on edge turbulence and transport in the H-1 Heliac" (PDF). Plasma Physics and Controlled Fusion. 59 (2): 024001. Bibcode:2017PPCF...59b4001M. doi:10.1088/1361-6587/59/2/024001. hdl: 1885/112461 . S2CID   73588015.
  25. ↑ Hole, M.J.; B.D. Blackwell; G. Bowden; M. Cole; A. Koenies; C.A. Michael; F. Zhao; S.R. Haskey (2017). "Global Alfven eigenmodes in the H-1 heliac". Plasma Physics and Controlled Fusion. 59 (12): 125007. arXiv: 1704.02089 . Bibcode:2017PPCF...59l5007H. doi:10.1088/1361-6587/aa8bdf. S2CID   119096017.
  26. ↑ Meshkani, S.; M. Ghoranneviss; A. Salar Elahi; M. Lafouti (2015). "Design and Fabrication of Comparative Langmuir Ball-Pen Probe (LBP) for the Tokamak". Journal of Fusion. 34 (2): 394–397. doi:10.1007/s10894-014-9811-5. ISSN   1572-9591. S2CID   121106547.
  27. ↑ S. Meshkani, M. Ghoranneviss, M. Lafouti, "Effect of Biasing on Electron Temperature in IR-T1 Tokamak", Proceedings of the 5th International Conference on Development, Energy, Environment, Economics (DEEE '14), Florence, Italy November 22–24, 2014
  28. ↑ Ghoranneviss, M.; S. Meshkani (2016). "Techniques for improving plasma confinement in IR-T1 Tokamak". International Journal of Hydrogen Energy. 41 (29): 12555–12562. doi:10.1016/j.ijhydene.2016.03.075.
  29. ↑ J. Cerovsky, M. Farnik, M. Sos, J. Svoboda, O. Ficker, M. Hetflejs, P. Svihra, M. Shkut, O. Grover, J. Veverka, V. Svoboda, J. Stockel, J. Adamek, M. Dimitrova, "Tokamak GOLEM for fusion education", 44th EPS Conference on Plasma Physic, 26–30 June 2017, Belfast, Northern Ireland (UK), P1.107,
  30. 1 2 Adamek, Jiri; J. Adamek; M. Peterka; P. Kudrna; M. Tichy T.; Gyergyek (2012). "CDiagnostics of magnetized low temperature plasma by ball-pen probe". Nukleonika. 57 (2): 297–300.
  31. ↑ Zanaska, Michal; J. Adamek; M. Peterka; P. Kudrna; M. Tichy (2015). "Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma". Physics of Plasmas. 22 (3): 033516. Bibcode:2015PhPl...22c3516Z. doi:10.1063/1.4916572.
  32. ↑ Peterka M., "Experimental and theoretical study of utilization of probe methods for plasma diagnostics", Diploma Thesis, Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, 2014 (only Czech language)
  33. ↑ Zanaska M., "Measurement of the plasma potential by means of the ball-pen and Langmuir probe", Bachelor thesis, Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, 2013 (only Czech language)
  34. ↑ G. Bousselin, J. Cavalier, J. Adamek, G. Bonhomme. "Ball-pen probe measurements in a low-temperature magnetized plasma", 39th EPS Conference & 16th Int. Congress on Plasma Physics, Stockholm, Sweden, P4.042 (2012)
  35. ↑ Bousselin, G.; J. Cavalier; J. F. Pautex; S. Heuraux; N. Lemoine; G. Bonhomme (2013). "Design and validation of the ball-pen probe for measurements in a low-temperature magnetized plasma". Review of Scientific Instruments. 84 (1): 013505–013505–8. Bibcode:2013RScI...84a3505B. doi: 10.1063/1.4775491 . ISSN   0034-6748. PMID   23387648.
  36. ↑ L. Šalamon, G. Ikovic, T. Gyergyek, J. Kovačič and B. Fonda, "Ball-pen probe diagnostics of a weakly magnetized discharge plasma column", 1st EPS conference on Plasma Diagnostics, 14–17 April 2015, Frascati, Italy,
  37. ↑ Silva, C.; J. Adamek; H. Fernandes; H. Figueiredo (2014). "Comparison of fluctuations properties measured by Langmuir and ball-pen probes in the ISTTOK boundary plasma". Plasma Physics and Controlled Fusion. 57 (2): 025003. Bibcode:2015PPCF...57b5003S. CiteSeerX   10.1.1.691.3443 . doi:10.1088/0741-3335/57/2/025003. S2CID   59151012.
  38. ↑ Stangeby P.C.: The Plasma Boundary of Magnetic Fusion Devices, Institute of Physics Publishing. Bristol and Philadelphia (2000).
  39. ↑ Hutchinson I.H.: Principles of Plasma Diagnostics, Cambridge University Press (1992).
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.