When a charged particle with charge $$q$$ and mass $$m$$ enters uniform magnetic field $$B$$ with velocity $$v$$ at right angles to $$B$$, the force on the moving particle is given by $$qvB$$. This force acts as the centripetal force making the charged particle go in a uniform circular motion with radius $$r=\frac{mv}{Bq}$$.Now if a hydrogen ion and a deuterium ion enter the magnetic field with velocities in the ratio 2:1 respectively, then the ratio of their radii will be __________.