rf ion source development for neutron generation and for material modification

TLDR

RF‑driven multicusp ion sources have been successfully employed across a range of applications. The group aims to develop RF ion sources for neutron production and high‑current, CW‑operated sources for SIMOX oxygen implantation. Their design features a 25 cm long, 5 cm diameter quartz plasma chamber with an external RF antenna, extraction electrode, and target assembly, a multi‑aperture high‑power neutron generator running at 80 kV, 150 mA deuterium beam on a 1 % duty cycle, and a dual‑antenna system for reliable long‑life CW operation. The neutron generator achieved a yield of 1.6 × 10⁷ neutrons per second.

Abstract

rf driven multicusp ion sources have been successfully used in various different applications. Lately the Plasma and Ion Source Technology Group at Lawrence Berkeley National Laboratory has been developing a rf ion source for neutron production and a high current density cw-operated ion source for SIMOX (Separation by Implantation of Oxygen)-application. The group has developed a small ion source, which consists of a quartz plasma chamber, an external rf-antenna, an extraction electrode, and a target assembly, all in a tube that is approximately 25 cm in length and 5 cm in diameter. Another neutron generator currently under development is a multiaperture, high power generator. The neutron generator currently operates at 1% duty cycle, 80 kV, and 150 mA of deuterium beam. The neutron yield measured from the generator is 1.6×107 n/s. For oxygen implantation, the group has been developing a source which could provide a high percentage of O+ at high current density using cw operation. A dual-antenna has been developed for the source to ensure reliable long life operation. The development of these sources will be discussed in this article.