Development of a 14.5 GHz all-permanent magnet multicharged ECR ion source for remote operation

Abstract

Collisions of slow (impact velocity below 25 keV/amu) multiply-charged ions (MCI) with atoms, molecules and solid surfaces is of considerable interest in various fields of modern research; e.g., thermonuclear fusion plasmas, astrophysical and ionospheric processes, surface analytics and nanotechnology. In this respect, the so-called electron cyclotron resonance (ECR) ion source, invented by the French physicist Richard Geller, has become a workhorse for the production of slow MCI beams. Commonly, the magnetic fields used to confine ECR-heated plasmas are produced by normal conducting or superconducting electromagnetic coils, the use of which has a high operating cost due to their energy consumption. In this thesis, the construction of and initial operational results from a novel 14.5 GHz ECR ion source, based on permanent magnets only, is described. This ion source has been built and tested both on a test bench and with a small ion accelerator for atomic collision experiments, both in the gas phase and on solid surfaces in ultra-high vacuum. The new ECR ion source can be operated remotely via a LabVIEW program and the Internet.<br />In this context we briefly recount some experimental activities on fast helium beam emission spectroscopy for boundary plasma diagnostics at JET, the world-leading Joint European Torus fusion experiment in Culham, England, where remote participation is commonly used.<br />