Design of a proton beamline specialized for radiation testing of semiconductors at KOMAC

Abstract

The demand for radiation hardness testing of semiconductor devices has been rapidly increasing, particularly for space and high-reliability applications. To address this need, a dedicated proton beamline for semiconductor radiation testing is being developed at the Korea Multipurpose Accelerator Complex (KOMAC) using an existing 100 MeV proton accelerator. The beamline is designed to deliver a large-area, low-flux proton beam suitable for displacement damage and single event effect tests. The beamline incorporates a graphite-based water-cooled collimator to reduce the beam intensity and a magnet optics system consisting of quadrupole and octupole magnets to generate a wide and uniform flat-top beam profile. Beam dynamics simulations were performed to evaluate different optics configurations under the geometrical constraints of the penetration pipe. The simulation results demonstrate that a beam size of 100 mm × 100 mm with a uniformity better than ± 10% can be achieved. The collimator was designed to withstand an average beam power of up to 800 W, and coupled thermal–structural analyses confirmed that both temperature rise and thermal stresses remain within safe limits. Radiation shielding analyses further verified that the resulting dose rates satisfy radiation safety requirements. In addition, two octupole electromagnets were designed, fabricated, and experimentally characterized, showing good agreement between measured and simulated magnetic field properties. A dedicated target room was also designed to support efficient semiconductor irradiation experiments, featuring real-time beam diagnostics, redundant beam on-off control, and an integrated control interface with the accelerator system. The proposed beamline is expected to significantly enhance proton irradiation capabilities at KOMAC and provide an effective testing platform for the semiconductor industry and related research fields.