Effectiveness of Some 0 dB Cryogenic Microwave Attenuators as Thermal Heatsinks

Abstract Coaxial cables are widely used in radiofrequency and microwave cryogenic setups for condensed matter and quantum experiments. Since the inner conductor of coaxes is often in good thermal contact with the sample to be measured, it is desirable to know the phononic heat channeled by the inner conductor. Although cryogenic attenuators are widely used to thermalize the inner conductor of coaxes, to our knowledge, quantitative information is not available. We present data on the effectiveness of three commercially available 0 dB attenuators as thermal heatsinks. In particular, we measured the temperature of the inner pin of several 0 dB attenuators under a heat load. This information will aid in designing and carefully controlling the thermal environment of samples in high-frequency experiments mounted in dilution refrigerators and on nuclear demagnetization stages.