CAPP-PACE Experiment with a Target Mass Range Around 10 μeV

Abstract

CAPP-PACE is a pilot experiment of IBS/CAPP for direct detection of axions with a mass around 10 μeV based on Sikivie’s microwave cavity scheme. The detector is equipped with an 8 T superconducting magnet and employs a dilution refrigerator that lowers the physical temperature of a high Q-factor split-type cavity to less than 45 mK. The frequency tuning system utilizes piezoelectric actuators with interchangeable sapphire and copper rods. The feeble signal (10−24 W) from the cavity is amplified and transmitted through the RF receiver chain with a HEMT amplifier whose noise temperature is around 1 K. I will present the results of CAPP’s first physics data runs in the axion mass range from 2.45 to 2.75 GHz and discuss our future plans and R&D projects.