An alpha particle of charge $+2$e $($e $=1\mathrm{.}61019$ C$)$ and mass $4$mp $($mp $=1\mathrm{.}661027$ kg$)$ and a doubly ionized oxygen atom $16$O$2+$ of charge $+2$e and mass $16$mp$,$ are both moving in the same uniform magnetic field. The velocities of both particles are at right angles to the magnetic field. The paths of the particles have the same radius of curvature. The ratio of the kinetic energy of the alpha particle $($E$)$ to that of the $16$O$2+($EO$)$ ion is