A high current multichannel (MEQALAC) system for ion implantation

Abstract

Due to the increasing interest in ion implantation into semiconductors and metals as well as in neutral particle heating and plasma diagnostics in fusion experiments, high current and high energy (MeV range) beams of light ions are required. In a collaboration between the FOM-Institute, Amsterdam and the Frankfurt University a Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) has been developed, which is able to accelerate parallel beams. This radio frequency (rf) device is useful for exit energies up to several MeV without the presence of a MV de-voltage. The parallel ion beams produced by a multiaperture ion source are transported via a low energy beam transport (LEBT) section to a modified interdigital-H-TE(111) resonator structure, where the simultaneous acceleration of the beams in a common rf-field takes place. The proof-of-principle MEQALAC at FOM operates at 40 MHz and accelerates four He + beams of 2.2 mA each up to 116 keV. The properties of this machine will be reported. In a second stage of this project a new system for the acceleration of ions (namely N + ) at various frequencies (19–25 MHz) to allow for a variation of output energy and ion species is being built. Only ∼ 2 m in length, this kind of rf-device could immediately be used for surface treatment of metals against corrosion.