**Abstract:**

The effect of quantum degeneracy on the work output from a Stirling cycle working at quantum degeneracy conditions ~QDCs! is analyzed. Expressions for net work outputs of Stirling power cycles working with monatomic ideal Bose and Fermi gases are derived by using the quantum ideal gas equation of state. Ratios of net work outputs of Stirling cycles working with Bose and Fermi gases to the net work output of a classical Stirling cycle (RW B and RW F , respectively! are obtained. Variations of RW B and RW F with TH are examined for a given temperature ratio (t5TL /TH) and a speciﬁc volume ratio (rn5nH /nL). At QDC, it is seen that RW B has a maximum value, which is greater than unity. On the other hand, there is no maximum or minimum point for RW F and RW F <1 for any values of TH . Consequently, the use of Bose gas as a working ﬂuid in a Stirling cycle provides an advantage since it causes the net work output per cycle to increase by consuming more heat energy. This fact is seen to be in the opposite direction for a Stirling cycle working with Fermi gas.

**H. SAYGIN** and A. ŞİŞMAN, “*Quantum degeneracy effect on the work output from a Stirling cycle*”, **Journal of Applied Physics**, Vol. 90, No. 6, pp. 3086–3089 **(2001)**.