Speaker
Description
A novel medium-current (up to 20 mA) and low normalized beam emittance (<1 π mm·mrad) ECR microwave H⁺ ion source has been developed at the Centre for Energy Research in Budapest, Hungary, to work as the serve as the core of a compact neutron source. Designed for high stability, the system aims for an energy ripple below 1%, delivering continuous or pulsed proton beams (20 mA) with adjustable pulse durations (0.1–10 ms) and modulation frequencies (0.01–40 Hz) at 35 keV. The configuration includes a microwave generator, four-stub tuner, E-bends, DC-break, vacuum window, and a four-section matching transformer, all connected to a 90 mm diameter, 100 mm length cylindrical plasma ionizing chamber. Magnetic fields are generated by six axially arranged permanent magnet bars. Magnetic simulations guided the placement of magnets and ferromagnetic components to achieve the desired field within the chamber. Beam simulations confirm effective proton beam focusing. High-voltage insulators are radially installed, minimizing the distance between the extraction slit and ion optic entrance. The extracted beam is diagnosed using a water-cooled Faraday cup. An infrared camera enables measurement of both beam current and its distribution.
Beam chopping is implemented via electrostatic deflection plates driven at ~3 kV, directing the beam to a Faraday cup acting as a beam dump. This approach avoids the challenges of high-voltage (35 kV) switching.
Measurement results are presented for both continuous and chopped beam modes.
