Temperature oscillations in thin metallic tapes with transport current at liquid nitrogen temperature

Temperature oscillations were observed in thin metallic tapes cooled by liquid nitrogen at current densities above 108 A/m2. A boiling hysteresis in the transition region between conductive heat transfer and nucleate boiling caused a temperature decrease and a change in the resistance of the tape. The differential resistance was negative and the current voltage curve had a non-linear character. The amplitude of the resistance change and character of the oscillations depended on the type of metal used, current ramp rate, geometry of the tape, and on its position with respect to the liquid surface. The effect was most pronounced in Ni tapes; the resistance change during the temperature drop achieved a value of about 30%. Dumped and un-dumped oscillations were observed after the temperature drop.