$\Omega^{IM}/\gamma_{ITG}>1$, whereas the slab like generated zonal flows have $\Omega^{IM}/\gamma_{ITG} \approx 1$. The modulus of real frequency ($|\Omega^{RE}|$) of the slab like generated zonal flows are, in comparison, much larger than the values from the corresponding toroidally generated zonal flow real frequency. The results support the findings that turbulence suppression is small in linear devices with small curvature (in the present paper represented with small $\epsilon_n$).

![The zonal flow growth rate (positive) and real frequency (negative) (normalized to the ITG mode growth) as a function of $\eta_i$ with $\epsilon_n = 0.0$ (diamond) and $\epsilon_n = 1.0$ (square) are displayed. The other parameters are $\tau = 1$, $k_x = k_y = q_x = 0.3$, $\mu = 0$ and $k_{\parallel}^2 = 0.1$.](Fig_2b.eps){height=".3\textheight"}

Third, the scaling of the zonal flow quality ($\Omega^{IM}/\Omega^{RE}$) as a function of parallel wave number ($k_{\parallel}^2$) is displayed in Figure 4. In the figure it is shown that the quality for the slab like generated zonal flows is quite insensitive to a change in the parallel wave number. This is due to a similar behavior of zonal flow growth rate and frequency with parallel wave number e.g. Figure 5. The quality of the toroidally generated zonal flows improves with 