The total ionization cross sections of He, Ne, Ar, Kr, Xe, H2, D2, N2, O2, CO, NO, CO2, N2O, and CH4 have been measured from threshold to 1000 eV in a total ionization tube. More limited measurements were performed in C2H4 and SF6. Great care was taken to assure complete collection of electron and ion currents, and the absence of spurious instrumental errors. A new method was devised for obtaining absolute cross sections of gases relative to H2, and a McLeod gauge was used to obtain the absolute cross section in H2. The cross sections in NO and O2 could not be obtained by this method, and an approximate correction to direct McLeod‐gauge readings was used for these gases. It is believed that the results are as accurate as is possible with the present method. It is difficult to explain the differences found between cross sections measured by various investigators. McLeod‐gauge errors appear to account for most of the difference in absolute magnitude.

1.
P. T.
Smith
,
Phys. Rev.
36
,
1293
(
1930
).
2.
J. T.
Tate
and
P. T.
Smith
,
Phys. Rev.
39
,
270
(
1932
).
3.
E. W. McDaniel, Collision Phenomena in Ionized Gases (John Wiley & Sons, Inc., New York, 1964), p. 174.
4.
W. L.
Fite
and
R. T.
Brackmann
,
Phys. Rev.
113
,
815
(
1959
).
5.
W. L.
Fite
and
R. T.
Brackmann
,
Phys. Rev.
112
,
1141
(
1958
).
6.
A. C. H.
Smith
,
E.
Caplinger
,
E. W.
Rothe
, and
S. M.
Trujillo
,
Phys. Rev.
127
,
1647
(
1962
).
7.
E. W.
Rothe
,
L. L.
Marino
,
R. H.
Neynaber
, and
S. M.
Trujillo
,
Phys. Rev.
125
,
582
(
1962
).
8.
P. T.
Smith
,
Phys. Rev.
37
,
808
(
1931
).
9.
W.
Bleakney
,
Phys. Rev.
35
,
139
(
1930
).
10.
W.
Bleakney
,
Phys. Rev.
33
,
1180
(
1930
).
11.
W.
Bleakney
,
Phys. Rev.
36
,
1303
(
1930
).
12.
H. Harrison, Ph.D. thesis, Catholic University of America, Washington, D.C., 1956.
13.
J. W.
Liska
,
Phys. Rev.
46
,
169
(
1934
).
14.
B. A.
Tozer
and
J. D.
Craggs
,
J. Electron.
8
,
103
(
1960
).
15.
F. W.
Lampe
,
J. L.
Franklin
, and
F. H.
Field
,
J. Am. Chem. Soc.
79
,
6129
(
1956
).
16.
B. L.
Schram
,
F. J.
de Heer
,
M. J.
van der Wiel
, and
J.
Kistemaker
,
Physica
31
,
94
(
1965
).
17.
R. K.
Asundi
and
M. V.
Kurepa
,
J. Electron. Control
15
,
41
(
1963
).
18.
R. K.
Asundi
,
J. D.
Craggs
, and
M. V.
Kurepa
,
Proc. Phys. Soc. (London)
82
,
967
(
1963
).
19.
D.
Rapp
,
P. E.
Golden
, and
D. D.
Briglia
,
Bull. Am. Phys. Soc.
10
,
181
(
1965
);
P. E. Golden and D. Rapp, Lockheed Missiles and Space Company Tech. Rept. 6‐74‐64‐12, January 1964.
20.
L. J. Kieffer, “A Compilation of Critically Evaluated Electron Impact Ionization Cross Section Data for Atoms and Diatomic Molecules,” Joint Institute for Laboratory Astrophysics Rept. No. 30, Boulder, Colorado, 5 February 1965.
21.
D. D.
Briglia
and
D.
Rapp
,
J. Chem. Phys.
42
,
3021
(
1965
).
22.
D.
Rapp
,
P. E.
Golden
, and
D. D.
Briglia
,
J. Chem. Phys.
42
,
4081
(
1965
).
23.
D. D.
Briglia
and
D.
Rapp
,
Rev. Sci. Instr.
36
,
1259
(
1965
).
24.
F. H. Field and J. L. Franklin, Electron Impact Phenomena (Academic Press Inc., New York, 1957), however, see Ref. 21 regarding the onset in H2.
25.
At pressures of ∼1 Torr and higher, this exponent goes to zero.
26.
The authors are particularly indebted to D. D. Briglia for pointing this out.
27.
E. W.
Rothe
,
J. Vac. Sci. Tech.
1
,
66
(
1964
);
H.
Ishii
and
K.
Nakayama
,
Trans. Natl. Vac. Symp.
8th 1961,
1
,
519
(
1962
);
C.
Meinke
and
G.
Reich
,
Vakuum‐Technik
11
,
86
(
1962
);
C.
Meinke
and
G.
Reich
,
12
,
79
(
1963
).,
Vak.-Tech.
28.
H. S. W. Massey and E. H. S. Burhop, Electronic and Ionic Impact Phenomena (Oxford University Press, New York, 1952).
29.
R. K.
Asundi
,
Proc. Phys. Soc. (London)
82
,
372
(
1963
).
30.
J. R. Pierce, Theory and Design of Electron Beams (D. Van Nostrand Company, Inc., New York, 1954), 2nd ed.
31.
J. B. Hasted, Physics of Atomic Collisions (Butterworths Scientific Publications, Ltd., London, 1964), pp. 169–173.
32.
D. D. Briglia (personal communication).
This content is only available via PDF.
You do not currently have access to this content.