Development of a dedicated ion injector for accelerator-based nanoprobe facilities

The paper discusses possible ways of increasing beam brightness in ion injectors. The argon/helium ion injector comprising a newly designed RF ion source and, a Wien filter has been designed for use in accelerator-based nanoprobe facilities. The phase set degradation due to aberrations in the injector ion-optic system was simulated with allowance for multipole and fringing fields. The RF ion sources with different permanent magnet systems were tested. Experiments were performed with argon and helium. A plasma density of up to 3×10¹¹ cm⁻³ and beam brightness of ∼100 A/(m² rad² eV) were obtained. The ion current density inside an extracting electrode in the source was 10 mA/cm² for an emission hole diameter of 0.6 mm. Measurements of the current value and emittance were performed with ion source testing equipment permitting measurements of the ion beam current, emittance, mass composition, and RF power input into the plasma.