高温超伝導サンプラーを用いた高周波電流波形観測

概要

論文の詳細を見る
We are developing a prototype system for measuring high-frequency current waveform flowing through a room-temperature sample without contact. It is based on a high-T C superconductor sampler that can measure current waveforms with pico-second resolution. The sampler chip is housed in a vacuum chamber and is cooled down to its operating temperature by a GM-pulse tube cryocooler. A current flowing through the sample, which is placed just below and outside the vacuum chamber, generates a magnetic field. The sampler can measure this current because a superconducting loop, which includes the comparator junction of the sampler, picks up the magnetic field. The system observed sinusoidal currents flowing through a 50-ohm microstrip line with correct periods up to 20 GH z. Their amplitudes, however, were reduced by jitter. The frequency dependence of the measurement sensitivity is another problem that must be overcome before the system can be put to practical use.
社団法人日本磁気学会の論文
2001-05-01