80 Chapter 3. Motion of a single plasma particle
̂
R̂
R
B
center of curvature
Figure 3.5: Local cylindrical coordinate system defined by curved magnetic field,ˆφ=B.ˆ
The drifts can be summarized as
v⊥gc=vE+v∇B+vc+vP (3.87)
where
- the ‘EcrossB’ drift is
vE=
E×B
B^2
(3.88)
- the ‘gradB’ drift is
v∇B=−
mv^2 L 0
2 qB^3
∇B×B (3.89)
- the ‘curvature’ drift is
vc=−
mv‖^2 gc
qB^2
B̂·∇B̂×B=^1
qB^2
(
mv‖^2 gcRˆ
R
)
×B (3.90)
- the ‘polarization’ drift is
vP=−
m
qB^2
[
d
dt
(vE+v∇B+vc)