Amass spectrograph is operated with deuterons, which have a charge of +e and a mass of 3.34 x 10-27 kg. deuterons emerge from the source, which is grounded with negligible velocity. the velocity of the deuterons as they pass through the accelerator grid is 8.0 x 105 m/s. a uniform magnetic field of magnitude b = 0.20 t, directed out of the plane, is present at the right of the grid. in the figure, the deuterons are in circular orbit in the magnetic field. the radius of the orbit and the initial sense of deflection are closest to: