The dose‐depth profiles for electrons extracted from a pulsed electron beam machine have been studied using a castable radiation‐sensitive plastic. These profiles exhibit a pronounced range shortening at charge fluences greater than 0.5 μC/cm2 which reaches a limiting value, corresponding to a limiting internal field, at fluences greater than 1 μC/cm2. This behavior is interpreted in terms of charge build‐up and relaxation by radiation‐induced conductivity in the host material, poly(vinyl toluene). Positive charge‐trapping additives reduce this conductivity and allow the internal field to build up at lower charge fluences. The ratio of radiation‐induced conductivity to dose rate derived from these measurements 1.6 × 10−18 sec/Ω‐cm rad compares favorably with the value found at low dose by direct measurement of 3.0 × 10−18 sec/Ω‐cm rad.

1.
Bernhard
Gross
,
J. Polymer Sci.
27
,
135
(
1958
).
2.
H.
Lackner
,
I.
Kohlberg
, and
S. V.
Nablo
,
J. Appl. Phys.
36
,
2064
(
1965
).
3.
J. E.
Rauch
and
A.
Andrew
,
IEEE Trans. Nucl. Sci.
NS‐13
,
109
(
1966
).
4.
Bernhard
Gross
and
S. V.
Nablo
,
J. Appl. Phys.
38
,
2272
(
1967
).
5.
J.
Dow
and
S. V.
Nablo
,
IEEE Trans. Nucl. Sci.
NS‐14
,
231
(
1967
).
6.
L. A.
Harrah
,
Radiation Res.
39
,
223
(
1969
).
7.
L. A.
Harrah
,
Radiation Res.
41
,
229
(
1970
).
8.
R. G. Kepler (unpublished).
9.
W. H. Buckalew and L. D. Posey, Electron Beam Diagnostics: Part I, SC‐RR‐69‐512 (1969), Sandia Laboratories, Albuquerque, N. M. (unpublished).
10.
H. E.
Boesch
, Jr.
and
A. S.
Hill
,
IEEE Trans. Nucl. Sci.
NS‐16
,
124
(
1969
).
11.
E. H.
Martin
and
J.
Hirsch
,
Solid State Commun.
7
,
279
(
1969
).
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