Development of a broadband shot noise measurement system at low-temperature for noise thermometry

We report our experimental setup for the shot noise thermometry system at KRISS. Precision RF measurement setup in the frequency range of about 1 GHz has been installed in a He-3 refrigerator, which can be cooled down to 300 mK. The shot noise of Al-AlOx-Al tunnel junction, fabricated by two angle- evaporation technique, was measured and compared with theoretical curve. The inferred temperature from the noise curve agrees well with the measured temperature.