[short talk] A Plan for Slow Positron Beam Facility in KAERI

by Dr Jaegi Lee (HANARO Utilization Division, Korea Atomic Energy Research Institute (KAERI))

Monday 6 Dec 2021, 14:30 → 15:30 Europe/Berlin

Zoom Webinar

Korea Atomic Energy Research Institute (KAERI) has been operating the High-Flux Advanced Neutron Application Reactor (HANARO) since 1995. In the HANARO reactor, seven horizontal beam ports are available, including a cold neutron source. KAERI has a plan to develop a slow positron beam facility to analyze the defect or free volume on the surface (< few μm) of the samples. The HANARO research reactor can generate a slow positron beam with high flux (> 1 × 10^8 e+/cm^2·s) based on the Monte Carlo simulations. To insert a positron converter in the HANARO reactor, one of the thermal neutron facilities should be moved. KAERI has a plan to make new thermal neutron beamlines using the ST1 port. After the immigration of thermal neutron facilities such as thermal-TAS, neutron radiography, and high resolution powder diffractometer, a slow positron beam facility could be built in the HANARO reactor.

HANARO utilization division in KAERI has been operating Na-22 isotope-based positron annihilation spectrometers for three years. Two positron annihilation lifetime spectrometers and one coincidence Doppler-broadening spectrometer are operating. Metal alloys were analyzed for defect change in different thermomechanical processes such as reduced activation ferritic/martensitic steels, structural materials in nuclear power plants, and aluminum ternary alloys. For polymers, polyethylene terephthalate as a waterproof film, polyamide membrane for reverse osmosis filter for the polluted water in nuclear power plant, and coating material for hydrogen container were received to calculate the free volume and fractional volume of the molecule. Also, silicon and silicon carbide wafers will be analyzed for the defect change after neutron transmutation doping.