physics 122 Lecture 02 October 1st 2013_final

# 1 2 qb qb v vy vx y m m 22 this describes

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: s also generate currents and hence magne;c ﬁelds. These ﬁelds aﬀect the mo;on of charged par;cles. In this chapter, we shall ignore the E and B ﬁelds formed by these par;cles. Instead, we will assume we are dealing with prescribed E and B ﬁelds [they do not change due to the mo;on of the charges]. Orbits Start with const E and B (spatially and temporally uniform) Take E=0, B along z. Intuitively, we know dv m = qv × B dt mvx = qBvy mvy = −qBvx mvz = 0 This gives a helical orbit → no forces in parallel direction Take B into page: ⊗ B ↑ qv Force is to the left for q&gt;0 (proton), Force is to the right for q&lt;0 (electron), (–) particles orbit in the RH sense. (+) particles orbit in the LH sense. Guiding Center Uniform E and B fields, E = 0 In this case, a charged particle has a simple cyclotron gyration. The equation of motion dv m = qv × B dt Taking z to be the direction of B = Bz mvx = qBv y mv y = − qBvx mvz = 0 2 qB ⎛ྎ...
View Full Document

## This document was uploaded on 01/17/2014.

Ask a homework question - tutors are online