An \( \alpha \)-particle (mass \( 4 \, \text{amu} \)) and a singly charged sulfur ion (mass \( 32 \, \text{amu} \)) are initially at rest. They are accelerated through a potential \( V \) and then allowed to pass into a region of uniform magnetic field which is normal to the velocities of the particles. Within this region, the \( \alpha \)-particle and the sulfur ion move in circular orbits of radii \( r_{\alpha} \) and \( r_{s} \), respectively. The ratio \( ( \frac{r_{s}}{r_{\alpha}} ) \) is _____
