Construction of a Relaxation Calorimeter
Equipped with
Top-Loading Type Dilution Refrigerator

To achieve low temperature calorimetric experiments efficiently, we have constructed a new relaxation calorimetry system equipped with a top-loading dilution system. The dilution refrigerator is constructed so as to be inserted in a variable temperature insert system with a diameter of 30 mm. Instead of the 1 K pot inside the IVC( inner vacuum can), condensation of 3He gas is attained by the heat exchange of VTI temperature. It is possible to attain dilution temperature within 15 hours from the sample setting, since the dilution unit is constructed in a small size. The cooling power and minimum temperature attained in experiments were 25 mW and 90 mK. The system will be used for measuring heat capacity from 90 mK up to 10 K continuously.

(by Y. Nakazawa & R. Yoshimoto)

	Fig. 1. Schematic drawing of the top-loading type dilution refrigerator available in the 30 mm φ variable temperature insert.
	Photo. 1.