[en] According to a theory based on energy balance, the radius ratio rsub(p)/r0 of a constant-current plasma pinch depends only value of the effective specific heat ratio γ of the pinched plasma. The value of γ for argon is computed as a function of temperature. From these values the constant-current pinch ratios are computed. The results show argon pinch ratios of about 0.08 from (2-4)x106K, rising to 0.18 at 1.1x107K and to 0.27 at 108K