An alpha-particle moves in a uniform magnetic field with an induction of 1.2 tesla (T) in a circle of 49 cm radius in the plane perpendicular to the lines of force. Find the speed and the kinetic energy of the particle.

Answer

`2.8 xx 10^(7) m//s.` 16 MeV.

Explanation

The momentum of the particle may be found from the condition `(mu^2)/R=2eBu`, since an alpha-particle is a doubly ionized helium atom. Having established the fact his is nonrelativistic particle, we find its velocity and kinetic energy from the equations.
`u=2e BR//m and K=2e^2 B^2 R^2//m`