Isoentropic compression

The cooling power in an isoentropic compression is given by eq. (7.1). It is obviously necessary to start from T < 0.32 K and perform an adiabatic solidification of a part of liquid 3He. It can be demonstrated [12] that ... 

For temperatures above 0.32 K, the entropy of liquid is higher than that of the solid as happens in all other materials (see Section 7.2.1) below 0.32 K, the situation is reversed. We remind that this property allows to cool the liquid by isoentropic compression (see Section 7.1). 

Based on the Maxwell relations, the definitions of the isothermal compressibility (Kj or jSr), the isoentropic compressibility (Ks or jSr), and the thermal expansion coefficient (a) can be written with the In V removed as, respectively. 

Similarly, through the definition of isothermal and isoentropic compressibility, the ratio and difference of Cp and Cy can also be simplified to... 

The ideal power consumption (Pij) related to isoentropic (adiabatic) compression can be calculated according to ... 

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