Medical cyclotrons need efficient sources of protons to

Last updated: 7/26/2022

Medical cyclotrons need efficient sources of protons to inject into their center. In one kind of ion source, hydrogen atoms (i.e., protons with one orbiting electron) are fed into a chamber where there is a strong magnetic field. Electrons in this chamber are trapped in tight orbits, which greatly increases the chance that they will collide with a hydrogen atom and ionize it. One such source uses a magnetic field of 90 mT, and the electrons' kinetic energy is 1.2 eV. If the electrons travel in a plane perpendicular to the field, what is the radius of their orbits? (mₑ =9.11x 10⁻³¹kg, qₑ = 1.60 x 10⁻¹⁹ C, 1eV = 1.6 x 10⁻¹⁹ J) Express your answer in meters to two significant figures.