3. The apparatus shown below is designed to measure the energy of alpha particles emitted by a radioactive source. (Alpha particles have a mass roughly four times the proton mass and a charge that is twice the proton charge.) The source is placed at the entrance of a channel that forms a quarter of a circle. A uniform magnetic field is applied perpendicular to the plane of the channel. Alpha particles with a specific velocity will make their way through the channel and be detected at the exit. All others will strike the walls and be lost. What is the range of values of B necessary to analyze alpha particles whose energy range up to 6 MeV? 10 cm Source Detector