Angular distribution function from axial density measurements in a mirror confinement experiment

The angular distribution of particle velocities in a magnetized plasma can be uniquely determined by measurement of the variation of density along a magnetic field line. From measurements on the 2XII mirror experiment, it is determined that the angular distribution of ions is monotonic and very closely approximates sin2aθ, where a = 2.25 and θ is the pitch angle at the center. Particles with sin θ < 0.72 communicate with the region outside the mirrors and comprise approximately 5% of the total density at the center.