Accessibility condition of wave propagation and multicharged ion production in electron cyclotron resonance ion source plasma

Abstract

A new tandem type source of electron cyclotron resonance (ECR) plasmas has been constructing for producing synthesized ion beams in Osaka University. Magnetic mirror field configuration with octupole magnets can be controlled to various shape of ECR zones, namely, in the 2nd stage plasma to be available by a pair mirror and a supplemental coil. Noteworthy correlations between these magnetic configurations and production of multicharged ions are investigated in detail, as well as their optimum conditions. We have been considering accessibility condition of electromagnetic and electrostatic waves propagating in ECR ion source plasma, and then investigated their correspondence relationships with production of multicharged ions. It has been clarified that there exits efficient configuration of ECR zones for producing multicharged ion beams experimentally, and then has been suggested from detail accessibility conditions on the ECR plasma that new resonance, i.e., upper hybrid resonance, must have occurred.

Enhanced Production of Multicharged Ions by Mixing Low Z Gas and Emittance Measurement on Electron Cyclotron Resonance Ion Source

“…Figure 1 shows the top view of our ECRIS consisting of the ion source, the beam line, and the ion beam irradiation system (IBIS). [8] We use the cartesian coordinate system with the origin at the center of the chamber. The magnetic field in the ECRIS consists of the octupole permanent magnets and mirror coils, main coil A, B, and adjustment coil C. The diagram in figure 1 shows the typical magnetic field in 𝑧 direction at the center of the cylindrical chamber.…”

Interaction between plasma and electromagnetic field in ion source of 10 cm ECR ion thruster

“…In the plasma, extraordinary (X), right and left hand circu-larly polarized (R and L) waves exist. [18,19] As microwave frequency is equal to that of the electron gyrating, ω = ω ce , R wave will become the ECR wave to heat electron, and cut off as ω ce < ω < ω R , where ω R = ω ce 2 + ω 2 pe + ω 2 ce 4 . As ω 2 = ω 2 ce + ω 2 pe , X wave will become upper hybrid resonant (UHR) wave to heat electrons, and cut off as ω R < ω < ω L , where ω L = − ω ce 2 + ω 2 pe + ω 2 ce 4 .…”

Cutoff limitation of left-hand polarization wave and candidates for further enhanced producing multicharged ions on ECRIS

“…On the other hand, our device makes it possible to understand phenomena in existing plasma parameters by taking advantage of the ability to measure their distributions in the ECR plasma. As a result of experimental verification of the efficiency of ECR [6][7][8] and consideration of the accessibility condition of electromagnetic wave propagation in the magnetized plasma in ECRIS, the possibility of highfrequency upper hybrid resonance (UHR) heating was shown [9]. By the way, the UHR is the lowestorder mode resonance of the electron Bernstein wave (Bn wave) that converts the mode from electromagnetic waves to electrostatic waves [1].…”