Author/Authors :
Yvon، نويسنده , , D and Cummings، نويسنده , , A and Stockwell، نويسنده , , W and Barnes، نويسنده , , P and Stanton، نويسنده , , C and Sadoulet، نويسنده , , B and Shutt، نويسنده , , T and Stubbs، نويسنده , , C، نويسنده ,
Abstract :
We have developed voltage and charge sensitive FET preamplifiers which feature ultra low noise, convenience and flexibility for phonon and ionization detectors operated at 20 mK. With an NJ132L J-FET, the white noise of the voltage amplifier is 1.1 nV/√Hz at room temperature and 0.9 nV/√Hz when the FET is cooled to ≈120 K; the 1f knee is below 100 Hz. The power dissipation of the FET, about 7 mW in our application, allows it to be used in a 4 K environment. With the same cooled FET, the charge amplifier has shown a noise of 120 e− rms with a total input capacitance of 45 pF.
