B1
??
Qualitatively plot the subset of $U$ and $V$ parameter values that result in stable ion motion in the 3D RF trap. Calculate the values of the characteristic points of the stability region for $\omega_\text{rf} = 3\cdot 10^7~\text{s}^{-1}$, $r_0=1~\text{mm}$ and the ions of rubidium $\rm ^{87}Rb^+$. Consider that the generator in the lab allows you to get this range of voltage values $|U| \in [0; \: 200]~\text{V}$ and $|V| \in [0; \: 400]~\text{V}$.
H1
Motion along each axis should be stable.
H2
The motion along the $z$-axis with parameters $a_z$, $q_z$ is stable if the motion along the $x$-axis with parameters $a_x=-a_z/2$, $q_x=-q_z/2$ is stable.