Microwave resonator with diffractive aperture excitation for ion sources and plasma traps

The invention proposes a new shape for the plasma chamber of the Electron Cyclotron Resonance (ECR) sources, ion sources used for particle accelerators. The new structure is characterized by a non-uniform cross-section, which better adapts to the conformation of the magnetic field. In addition, a new microwave launch pattern is proposed on the wall of the chamber.

How does it work?

The idea consists of a resonant cavity for magnetised plasmas of the ECR ion sources that breaks the cylindrical symmetry used so far. The new shape of the cavity is substantially imposed by the 3D structure of the plasma (and, therefore, of the magnetic field) and guarantees greater efficiency in heating the electrons. These new structures also make it possible to use microwave launch systems consisting of waveguides obtained in the chamber structure itself, from which diffractive slits open, and allow for a deep optimization also of the cooling systems and spaces in general. It is a new concept of Radio Frequency (RF) – plasma coupling for ECR Sources that is proposed with two innovative approaches: a) through the new shape of the plasma chamber for a more efficient heating of the electrons; b) through the reconfiguration of the relative microwave launch system by means of radiant openings along the side walls of the chamber.

Applications

Production of ion sources for:

• Particle Accelerators;
• Plasma Enhanced Chemical Vapour Deposition (PECVD);
• Industrial applications;
• Microelectronics;
• Treatment and analysis of materials;
• Hadrontherapy.

Advantages

• More room in the injection flange;
• Better coupling of the electromagnetic field;
• Optimization of plasma confinement;
• Improvement of the overall efficiency of the system.