Publication

SWISSCASE : development and characterization of an electron cyclotron resonance ion source for the calibration of space flight instruments

Michael Bodendorfer
2008
Theses

Abstract

This PhD thesis consists of planning, simulating, building, testing and characterizing a new electron cyclotron resonance (ECR) ion source, SWISSCASE. the Solar Wind Ion Source Simulator for the CAlibration of Space Experiments located at the University of Bern, Switzerland. The ion source will be operated in the existing CASYMS ultra high vacuum (UHV) facility and will extend the application field of the existing filament electron collision ion source inside CASYMS and the existing electron cyclotron resonance ion source MEFISTO, operated in its own UHV facility. The chosen ECR ionization concept operating at 10.88 GHz delivers high currents of highly charged ions of up to 2 µA for Ar8+ and a maximum identified charge state of Ar12+. In addition to argon, the ECR plasma of SWISSCASE has been operated with krypton, xenon and carbon dioxide gas, revealing all of the expected charge states and featuring a charge states distribution in favor of highly charged ions. Design constraints were given by the final application of SWISSCASE being implemented in CASYMS with limited space and power. The new ion source was realized with limited funding. Numerical simulations gave insight in unprecedented quality and detail about the complex three dimensional extent of the magnetic field distribution of the full permanent magnet confinement of both, SWISSCASE and MEFISTO, the second ECR ion source, operated since 1997 at the University of Bern. For both confinement systems, the isocontour surface, defined by the electron cyclotron resonance condition of the incident microwave, is visualized in 3D. In addition to the realization of the ECR ion source, a plasma Bremsstrahlung measurement revealed an average ECR electron temperature of 10 keV for an argon plasma. This temperature was used to perform numerical simulations of electron trajectories inside the SWISSCASE and the MEFISTO confinement. The simulated magnetic field distribution of MEFISTO and the simulated electron distribution of SWISSCASE are closely related to the observed triangle shaped surface coating patterns found in hexapole confined ECR ion sources.

Official source

https://infoscience.epfl.ch/entities/publication/4a26c239-49ce-43c9-a4ee-c7e722491acd

Michael Bodendorfer
2008
Theses

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/4a26c239-49ce-43c9-a4ee-c7e722491acd

Related concepts (29)

Electron cyclotron resonance

Electron cyclotron resonance (ECR) is a phenomenon observed in plasma physics, condensed matter physics, and accelerator physics. It happens when the frequency of incident radiation coincides with the natural frequency of rotation of electrons in magnetic fields. A free electron in a static and uniform magnetic field will move in a circle due to the Lorentz force. The circular motion may be superimposed with a uniform axial motion, resulting in a helix, or with a uniform motion perpendicular to the field (e.

Ion source

An ion source is a device that creates atomic and molecular ions. Ion sources are used to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines. Electron ionization Electron ionization is widely used in mass spectrometry, particularly for organic molecules. The gas phase reaction producing electron ionization is M{} + e^- -> M^{+\bullet}{} + 2e^- where M is the atom or molecule being ionized, e^- is the electron, and M^{+\bullet} is the resulting ion.

Inertial electrostatic confinement

Inertial electrostatic confinement, or IEC, is a class of fusion power devices that use electric fields to confine the plasma rather than the more common approach using magnetic fields found in magnetic confinement fusion (MCF) designs. Most IEC devices directly accelerate their fuel to fusion conditions, thereby avoiding energy losses seen during the longer heating stages of MCF devices. In theory, this makes them more suitable for using alternative aneutronic fusion fuels, which offer a number of major practical benefits and makes IEC devices one of the more widely studied approaches to fusion.

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