A proton (charge + e, mass mp), a deuteron (charge + e, mass 2mp), and an alpha particle (charge + 2e, mass 4mp) are accelerated through a common potential difference 0V. Each of the particles enters a uniform magnetic field B, with its velocity in a direction perpendicular to B. The proton moves in a circular path of radius rp. Determine the radii of the circular orbits for the deuteron, rd, and the alpha particle, r1, in terms of rp.