Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant cavities.In this paper,we describe the cryogenic readout system calibration of a 7.138 GHz cop...Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant cavities.In this paper,we describe the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factor Q_(1)=10^(4)whose operation at a temperature of 22 mK is based on a dilution refrigerator.Our readout system consists of High Electron Mobility Transistors working as cryogenic amplifiers at 4 K,plus room-temperature amplifiers and a spectrum analyzer for signal power detection.We tested the system with a superconducting two-level system based on a single-photon source in the microwave frequency regime.We obtained an overall 95.6 dB system gain and–71.4 dB attenuation in the cavity's input channel.The effective noise temperature of the measurement system is 7.5 K.展开更多
基金supported in part by the Scientific Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20190049)the International Partnership Program of Chinese Academy of Sciences for Grand Challenges(112311KYSB20210012)+1 种基金the National Natural Science Foundation of China(12074117,92365209,12150010,11875062,11947302,12047503,12074117,61833010,12061131011,12150410317,11905149,12275333)the Beijing Natural Science Foundation(IS23025)。
文摘Possible light bosonic dark matter interactions with the Standard Model photon have been searched using microwave resonant cavities.In this paper,we describe the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factor Q_(1)=10^(4)whose operation at a temperature of 22 mK is based on a dilution refrigerator.Our readout system consists of High Electron Mobility Transistors working as cryogenic amplifiers at 4 K,plus room-temperature amplifiers and a spectrum analyzer for signal power detection.We tested the system with a superconducting two-level system based on a single-photon source in the microwave frequency regime.We obtained an overall 95.6 dB system gain and–71.4 dB attenuation in the cavity's input channel.The effective noise temperature of the measurement system is 7.5 K.
