Geoscience Reference
In-Depth Information
R
1
r
*
R
2
a
r
DISTANCE FROM CENTER
Fig. 3.16
Same as in Fig.
3.13
.Atnegativeenergies,
E
< 0, the situation is knottier. Ions with
L<L.r
/ reach the particle surface if L.r
/<L.R/. Otherwise, only ions with L<L.R/can
reach the particle surface
surface only if the energy
E
exceeds the value defined by the conditions
@L
2
.r/
@r
D
0; L
2
.r/
D
0
The energy is always positive at
E
> 0, but the ion reaches the particle surface if
E
exceeds the threshold energy. Then the ions with L<L.r
/ reach the particle
surface.
No problem comes up for monotonous repulsion alone. In this case
L
a
D
L
2
.a/
D
2ma
2
.E
U.a//
The lower integration limit over
E
is always U.r/.
