The Buneman–Hartree condition is re-examined in a cylindrical, smooth-bore, relativistic magnetron using both the conventional, single particle model, and the Brillouin flow model. These two models yield the same result for the Buneman–Hartree condition only in the limit of a planar magnetron. When b/a=1.3, where a is the cathode radius and b (>a) is the anode radius, the difference in the two models becomes significant. When b/a=4 the difference is acute, the Buneman–Hartree magnetic field at a given voltage in the Brillouin flow model exceeds four times that in the single particle model. Such a difference is always present, whether the voltage is relativistic or not. These results are quantified for b/a1 using Davidson’s model, conveniently cast in terms of the normalized gap voltage and normalized magnetic flux imposed on the cylindrical magnetron. A comparison with the University of Michigan/L-3 relativistic magnetron experiment is given.

1.
J. C.
Slater
,
Microwave Electronics
(
Van Nostrand
,
New York
,
1951
), p.
302
.
2.
J.
Benford
,
J. A.
Swegle
, and
E.
Schamiloglu
,
High Power Microwaves
, 2nd ed. (
Taylor & Francis
,
New York
,
2007
).
3.
R. J.
Barker
,
N. C.
Luhmann
,
J. H.
Booske
, and
G. S.
Nusinovich
,
Modern Microwave and Millimeter Wave Power Electronics
(
IEEE
,
Piscataway, NJ
,
2004
).
4.
V. L.
Granatstein
and
I.
Alexeff
,
High-Power Microwave Sources
(
Artech House
,
Norwood, MA
,
1987
).
5.
R. C.
Davidson
,
Physics of Nonneutral Plasmas
(
Addison-Wesley
,
Redwood City, CA
,
1990
).
6.
Y. Y.
Lau
, in
High-Power Microwave Sources
, edited by
V. L.
Granatstein
and
I.
Alexeff
(
Artech House
,
Norwood, MA
,
1987
), p.
309
.
7.
R. M.
Gilgenbach
,
Y. Y.
Lau
,
H.
McDowell
,
K. L.
Cartwright
, and
T. A.
Spencer
, in
Modern Microwave and Millimeter Wave Power Electronics
, edited by
R. J.
Barker
,
N. C.
Luhmann
,
J. H.
Booske
, and
G. S.
Nusinovich
, (
IEEE
,
Piscataway, NJ
,
2004
) Chap. 6.
8.
R. L.
Walker
, in
Microwave Magnetrons
, edited by
G. B.
Colloins
(
McGraw-Hill
,
New York
,
1948
), p.
227
.
9.
J. R. M.
Vaughan
,
IEEE Trans. Electron Devices
20
,
818
(
1973
).
10.
It is often forgotten that the orbital theory results, Eqs. (3) and (4), are also valid even when there is an axisymmetric space charge distribution in a cylindrical crossed-field gap. Since these two equations compare the energy and canonical angular momentum of an electron at the anode and at the cathode, an axisymmetric space charge distribution would not alter these quantities at the end points (anode and cathode). The simple derivation of the BH condition toward the end of Appendix  A illustrates this fact which was mentioned in Refs. 1 and 8.
11.
R. C.
Davidson
,
G. L.
Johnston
,
K. T.
Tsang
, and
A. T.
Drobot
,
Proc. SPIE
1061
,
186
(
1989
).
12.
T. M.
Antonsen
and
E.
Ott
,
Phys. Fluids
19
,
52
(
1976
).
13.
E.
Ott
and
R. V.
Lovelace
,
Appl. Phys. Lett.
27
,
378
(
1975
).
14.
R.
Kowalczyk
,
Y. Y.
Lau
,
T. M.
Antonsen
,
J. W.
Luginsland
,
D. P.
Chernin
,
C. B.
Wilsen
,
W.
Tang
, and
R. M.
Gilgenbach
,
IEEE Trans. Electron Devices
52
,
2087
(
2005
).
15.
Y. Y.
Lau
and
D. P.
Chernin
,
Phys. Fluids
B4
,
3473
(
1992
).
16.
B. E.
Carlsten
,
R. J.
Faehl
,
M. V.
Fazio
,
W. B.
Haynes
,
R. D.
Ryne
, and
R. M.
Stringfield
,
IEEE Trans. Plasma Sci.
22
,
730
(
1994
).
17.
D.
Price
,
J. S.
Levine
, and
J. N.
Benford
,
IEEE Trans. Plasma Sci.
26
,
256
(
1998
).
18.
M. D.
Haworth
,
K. L.
Cartwright
,
J. W.
Luginsland
,
D. A.
Shiffler
, and
R. J.
Umstattd
,
IEEE Trans. Plasma Sci.
30
,
992
(
2002
).
19.
J.
Benford
,
F. J.
Agee
,
D. M.
Goebel
,
F.
Hegeler
,
K. J.
Hendricks
,
R. M.
Gilgenbach
,
C.
Grabowski
,
H.
Jory
, and
J. P.
Verboncoeur
, in
High-Power Microwave Sources and Technologies
, edited by
R. J.
Barker
and
E.
Schamiloglu
(
IEEE
,
New York
,
2001
) Chap. 4;
K. J.
Hendricks
,
J.
Benford
,
J.
Eastwood
,
M.
Friedman
,
M.
Haworth
,
R. W.
Lemke
,
J.
Luginsland
,
R. B.
Miller
, and
J.
Pasour
,
High-Power Microwave Sources and Technologies
, (
IEEE
,
New York
,
2001
) Chap. 3;
Also,
F. J.
Agee
,
IEEE Trans. Plasma Sci.
26
,
235
(
1998
).
20.
Y. Y.
Lau
,
J. W.
Luginsland
,
K. L.
Cartwright
, and
M. D.
Haworth
,
Phys. Rev. Lett.
98
,
015002
(
2007
).
21.
O.
Buneman
, in
Crossed-Field Microwave Devices
, edited by
E.
Okress
(
Academic
,
New York
,
1961
), p.
218
.
22.
A.
Palevsky
, Ph.D. dissertation,
Massachusetts Institute of Technology
, Cambridge, MA,
1980
.
23.
T. J.
Orzechowski
and
G.
Bekefi
,
Phys. Fluids
22
,
978
(
1979
).
24.
A.
Palevsky
and
G.
Bekefi
,
Phys. Fluids
22
,
986
(
1979
).
25.
P. J.
Christenson
,
D.
Chernin
,
A.
Gardner
, and
Y. Y.
Lau
,
Phys. Plasmas
3
,
4455
(
1996
).
26.
P. J.
Christenson
and
Y. Y.
Lau
,
Phys. Plasmas
1
,
3725
(
1994
);
P. J.
Christenson
and
Y. Y.
Lau
,
Phys. Rev. Lett.
76
,
3324
(
1996
).
[PubMed]
27.
P.
Mardahl
and
J.
Watrous
, personal communication.
28.
G. D.
Sims
, in
Crossed-Field Microwave Devices
, edited by
E.
Okress
(
Academic
,
New York
,
1961
), p.
180
.
29.
V. B.
Neculaes
,
R. M.
Gilgenbach
, and
Y. Y.
Lau
,
Appl. Phys. Lett.
83
,
1938
(
2003
);
V. B.
Neculaes
,
R. M.
Gilgenbach
, and
Y. Y.
Lau
, U.S. Patent No. 6,872,929 (29 March
2005
);
V. B.
Neculaes
,
R. M.
Gilgenbach
, and
Y. Y.
Lau
, U.S. Patent No. 6,921,890 (26 July
2005
).
30.
V. B.
Neculaes
,
P.
Pengvanich
,
Y.
Hidaka
,
Y. Y.
Lau
,
R. M.
Gilgenbach
,
W. M.
White
,
M. C.
Jones
,
H. L.
Bosman
, and
J. W.
Luginsland
,
IEEE Trans. Plasma Sci.
33
,
654
(
2005
).
31.
M. C.
Jones
,
V. B.
Neculaes
,
Y. Y.
Lau
,
R. M.
Gilgenbach
, and
W.
White
,
Appl. Phys. Lett.
85
,
6332
(
2004
).
32.
M. C.
Jones
,
V. B.
Neculaes
,
Y. Y.
Lau
,
R. M.
Gilgenbach
,
W. M.
White
,
B. W.
Hoff
, and
N. M.
Jordan
,
Appl. Phys. Lett.
87
,
081501
(
2005
).
33.
M.
Fuks
and
E.
Schamiloglu
,
Phys. Rev. Lett.
95
,
205101
(
2005
).
34.
J. I.
Kim
,
J. H.
Won
,
G. S.
Park
,
H. J.
Ha
, and
J. C.
Shon
,
Appl. Phys. Lett.
88
,
221501
(
2006
).
35.
P.
Pengvanich
,
V. B.
Neculaes
,
Y. Y.
Lau
,
R. M.
Gilgenbach
,
M. C.
Jones
,
W. M.
White
, and
R. D.
Kowalczyk
,
J. Appl. Phys.
98
,
114903
(
2005
).
36.
P.
Pengvanich
,
Y. Y.
Lau
,
E.
Cruz
,
R. M.
Gilgenbach
,
B.
Hoff
, and
J. W.
Luginsland
,
Phys. Plasmas
15
,
103104
(
2008
).
37.
E. J.
Cruz
,
B. W.
Hoff
,
P.
Pengvanich
,
Y. Y.
Lau
,
R. M.
Gilgenbach
, and
J. W.
Luginsland
,
Appl. Phys. Lett.
95
,
191503
(
2009
).
38.
K. D.
Bergeron
,
Appl. Phys. Lett.
28
,
306
(
1976
);
K. D.
Bergeron
,
Phys. Fluids
20
,
688
(
1977
).
39.
S.
Riyopoulos
,
Phys. Rev. E
47
,
2839
(
1993
).
You do not currently have access to this content.