Physics of Plasmas and Ionized Media

(P4F2 and P4F2A)

The study program covers all aspects of plasma physics and with extensions to theoretical physics (elementary processes) and to some topics of astrophysics (interplanetary space plasma, dust / ice cloud problems in the solar system) and nuclear fusion. Studies include also borderline disciplines such as plasma chemistry, plasma interaction with solid surface and complex plasma. The program prepares professionals with a broad foundation in mathematics, physics, and computer modeling of physical processes and with deep knowledge of plasma physics.

Research fields are more or less defined by the current projects at our department and it similarly applies to the cooperating institutes of Czech Academy of Sciences.


Space Physics group is involved in a number of space plasma missions and its members interpret the data in following fields:

  1. Solar wind properties on large and small scales (experimental and theoretical investigations)
  2. Interaction of the solar wind with the magnetosphere
  3. Dust and dusty plasma in space and laboratory conditions
  4. Waves and wave–particle processes in the magnetosphere of Earth and planets

Plasma Physics group deals with elementary processes and transport phenomena in low-temperature plasma with an accent on diagnostic methods and applications:

  1. Elementary processes relevant to astrophysical environment (in laboratory and in simulations)
  2. Low-temperature plasma and its diagnostics
  3. Hot plasma in the magnetic field (e.g., tokamak)
→ Both groups develop new measuring methods for space applications and plasma technologies
Cooperating institutes

Available PhD Topics

It's always a good idea, if you find a topic for you, to contact supervisor first, i.e., prior application!

Reactions of anions with neutral molecules at low temperatures


Supervisor: Doc. RNDr. Radek Plašil, Ph.D.

Group of Plasma Physics and Numerical Simulations

The role of negative ions—anions—in interstellar space has been debated for many years. However, anions were only detected in interstellar gas clouds in 2006. They are also found in the gaseous tails of comets and planetary atmospheres. Now their reactions are being studied to explain astrochemical processes.

The proposed work aims to study the reactions of anions with neutral molecules and determine their rate coefficients as a function of temperature. With the equipment available in our laboratory, it is possible to study the reactions of selected anions with neutral atoms and molecules in the temperature range of 10 - 300 K. Simple anions consisting of carbon, oxygen, and hydrogen atoms will be selected for the study. Their reactions with neutral molecules present in interstellar space such as H2, HD, CO and the formation of larger molecular ions will be investigated. 

Low-temperature ion trap apparatus and laser absorption spectroscopy will be used for the study. The necessary experimental equipment in our laboratory is fully operational.

Literature:

  • [1] Smith I.W.M., Low temperatures and cold molecules, World Scientific Publishing, 2008, ISBN 978-1-84816-209-9.
  • [2] Millar T. J., C. Walsh, and T. A. Field. “Negative Ions in Space.” Chemical Reviews 117, no. 3 (2017) 1765–95. doi: 10.1021/acs.chemrev.6b00480
  • [3] P.K. Ghosh, Ion Traps, Clarendon Press, Oxford, 1995.
  • [4] Atkins P.W., Physical Chemistry, Oxford University Press, 2002, ISBN 0-19-879285-9.
  • [5] Massey H.S.W., Negative Ions, Cambridge University Press, Cambridge, 1974.
  • Other papers will be recommended by the supervisor

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Space plasma environment of Mars


Supervisor: Prof. RNDr. František Němec, Ph.D.

Space Physics Group

Mars, unlike Earth, lacks a global magnetic field that would shield it from the direct influence of the solar wind. Instead, the solar wind induces currents in the ionosphere, forming what is known as an induced magnetosphere. A magnetic pile-up boundary can be identified, along with a bow shock farther upstream due to the supersonic nature of the solar wind. The interaction is further complicated by the presence of remnant crustal magnetic fields, which locally influence the interaction and the ionospheric conditions. As a result, Mars exhibits a highly variable plasma environment governed by numerous factors, fostering irregularities and wave phenomena.

The aim of the thesis is to use plasma and wave measurements from recent spacecraft missions (Mars Express, MAVEN) to investigate the variability of the Martian ionosphere and its interaction with the solar wind. Particular attention is given to wave phenomena, especially in regions of crustal magnetic fields. The study involves both systematic analyses of all available data and case studies of specific events and their effects on the Martian plasma environment. Modern data processing methods, including the potential use of machine learning algorithms, are envisaged to be employed throughout the thesis.

Literature

D. A. Gurnett, A. Bhattacharjee: Introduction to Plasma Physics: With Space, Laboratory and Astrophysical Applications. Cambridge University Press, 2005. M. G. Kivelson, C. T. Russell: Introduction to Space Physics. University Press, Cambridge, 1995. G. K. Parks: Physics of Space Plasmas: An Introduction. 2nd ed. Westview Press, 2004. Papers in scientific journals recommended by the thesis supervisor.

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Mapping the distribution and composition of dust around Saturn


Supervisor: RNDr. Libor Nouzák, Ph.D.

Space Physics Group

Interplanetary space is not empty but is filled with the solar wind plasma and small objects of various material of micrometer and sub-micrometer size of different shapes called dust. This dust is mostly the product of cometary debris or the collisional cascade of larger objects (e.g., asteroids, micrometeoroids, or space debris). On the other hand, dusty environments around the moons or ringed planets in the interplanetary space can be also populated by ejecta of micrometeoroid bombardment of moon surfaces (e.g., Moon, Europa, etc.) or by volcanic (Io) or thermal activity of the moons themselves (Enceladus). The physical properties of dust particles can be studied in-situ by using both electric field antennas located on the spacecraft and special dust detectors that are designed for each dust environment separately, thus are rarely present. The electric field antennas are a part of the plasma wave subsystem on each spacecraft and the dust is detected as a transient event (spike) in the electric field data. The dust flux is estimated from the abundance of spikes in the data. The ratio of antenna signals provides information about the flux direction, while the size of the signals brings information about the mass of dust particles present in the flux. This approach has been successfully employed on the Parker Solar Probe and Solar Orbiter spacecraft to measure alpha and beta meteroids in the close vicinity of the Sun as well as to determine interplanetary dust flux variation with radial distance from the Sun and solar cycle. We suppose to employ the same detection method for analysis of the Saturn and its rings at different radial distances from Saturn using the Cassini spacecraft. In this case, we plan to involve data from the CDA (Cosmic Dust Analyser) instrument located on board Cassini with motivation to obtain supplementary information about the dust particles detected by the antenna instruments.

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