Speaker
Description
Axion is originally proposed by Peccei and Quinn to solve the mystery of the apparent CP conservation in Quantum Chromodynamics. With so called the strong CP problem, axion has cogent reasons to be a promising candidate of dark matter. Sikivie’s proposition, where the microwave cavity resonantly enhances the photon from axion-to-photon coupling in a strong magnetic field, is the most sensitive way to detect the axion up to date. Typically O(10−23) W of conversion power and its unknown mass, however, are still difficulties in being sensitive to the conversion signal down to the lower limit of theoretical predictions. The CAPP-MAX in IBS-CAPP is one of the most sensitive axion dark matter experiments around the world, and one of only a few experiments which is sensitive down to such limit after ADMX. It accommodates a dilution refrigerator below 30 mK of base temperature, a large-bore 12 T superconducting magnet, a microwave cavity with 37 L volume, readout chain including series of Josephson parametric amplifiers with added noise close to the standard quantum limit. The system has been successfully operated in the past two years and exclude the axion-to-photon coupling in 1.02 - 1.18 GHz range with DFSZ level sensitivity. In this presentation, I will present in detail about the overall experimental design, data taking and analysis. The upcoming science run targeting to 1.2 - 1.5 GHz scan at DFSZ sensitivity with a superconducting tuning rod and 6 JPA system will also be discussed.
