Abstract
A very low-noise, variable temperature insert for a standard liquid-helium cryostat has been developed. The design provides a 10-100 K operating range, with temperature stability better than 20 mK in the range 25-100 K, improving to 2 mK below 25 K. This temperature stability figure is obtained by balancing the cooling power due to the thermal coupling of the sample to liquid helium, with the heating power of a stream of room-temperature He gas flowing through a heat exchanger. The heating power is continuously regulated within a feedback loop by throttling the gas flow with a proportional valve, using the error signal from the temperature controller. The system provides good temperature stability without the need for low-resistance leads in the vicinity of the sample holder as those needed to feed an electrical heater. This is relevant to experiments where electromagnetic interference must be minimized.
Original language | English |
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Pages (from-to) | 2071-2075 |
Number of pages | 5 |
Journal | Review of Scientific Instruments |
Volume | 68 |
Issue number | 5 |
DOIs | |
State | Published - 1 Jan 1997 |
ASJC Scopus subject areas
- Instrumentation