Reduction of vibrational noise from continuously filled 1 K pots

We have examined the vibrational noise originating from 1.3 K pumped helium chambers (1 K pots) that are continuously filled from the 4.2 K bath throu gh an impedance. The noise can be largely eliminated by either heating the pot or by heating the impedance directly. Noise in 1 K pots has detrimental consequences for the operation of audio frequency torsional oscillators an d for high precision thermometry. (C) 1998 American Institute of Physics. [ S0034-6748(98)03512-6].