Geoscience Reference
In-Depth Information
2D/v
T
l = infty
2D/v
T
l = 2
2D/v
T
l = 1
2D/v
T
l = 2/3
10
1
1
10
100
PARTICLE DIAMETER (nm)
Fig. 3.21
Good agreement is illustrated between the theory and experiment. Shown is the
enhancement factor versus particle size for four ratios of 2D=
v
T
l
c
4Dl
c
1
exp .
l
c
=R.a//
˛.a/
D
(3.192)
where R.a/
D
4D=
v
T
for small particles. Because all ion-carrier gas collisions
lead to the loss of ion energy and are thus responsible for ion capture happening
inside the free molecule zone, then this consideration takes them into account.
We compared the charging efficiency of a neutral metallic particle with the
experimental data of Pui et al. (
1988
)(Fig.
3.21
). We calculated the enhancement
factor (charging efficiency/condensation efficiency). The enhancement is related to
the action of the image forces between the particle and the ion. The calculations
were done for the ratios 2D=
v
T
from Pui's paper (Pui et al.
1988
). The last value,
