We present measurements of the scattering, reflection, absorption, and transmission of a 1.5 MW, 110 GHz quasioptical gyrotron beam by a self-induced air breakdown plasma. The breakdown forms a periodic array of plasma filaments, oriented parallel to the incident electric field polarization that propagates toward the microwave source. For incident intensity of 3 MW/cm2, calorimetric measurements show that as much as 45% of the full beam power is absorbed by the plasma, averaged over the pulse, 1% is reflected backward, and the remainder is transmitted and also scattered into a wide angular spread. We observe that approximately 10 times more power is scattered in the direction perpendicular to the filaments than parallel. The far-field angular distribution of transmitted power exhibits a diffraction pattern that changes throughout the 2-μs life of the plasma.

1.
K. L.
Felch
,
B. G.
Danly
,
H. R.
Jory
,
K. E.
Kreischer
,
W.
Lawson
,
B.
Levush
, and
R. J.
Temkin
,
Proc. IEEE
87
,
752
781
(
1999
).
2.
T.
Imai
,
N.
Kobayashi
,
R.
Temkin
,
M.
Thumm
,
M. Q.
Tran
, and
V.
Alikaev
,
Fusion Eng. Des.
55
,
281
289
(
2001
).
3.
J. L.
Doane
and
R. A.
Olstad
,
Fusion Sci. Technol.
53
,
39
53
(
2008
).
4.
M. A.
Shapiro
,
E. J.
Kowalski
,
J. R.
Sirigiri
,
D. S.
Tax
,
R. J.
Temkin
,
T. S.
Bigelow
,
J. B.
Caughman
, and
D. A.
Rasmussen
,
Fusion Sci. Technol.
57
,
196
207
(
2010
).
5.
Y.
Oda
,
K.
Komurasaki
,
K.
Takahashi
,
A.
Kasugai
, and
K.
Sakamoto
,
J. Appl. Phys.
100
,
113307
(
2006
).
6.
V.
Granatstein
and
G.
Nusinovich
,
J. Appl. Phys.
108
,
063304
(
2010
).
7.
D.
Anderson
,
A.
Kim
,
M.
Lisak
, and
K.
Madsen
,
J. Plasma Phys.
63
,
329
341
(
2000
).
8.
E.
Koretzky
,
S. P.
Kuo
, and
J.
Kim
,
J. Plasma Phys.
59
,
315
332
(
1998
).
9.
A. L.
Vikharev
,
A. M.
Gorbachev
,
A. V.
Kim
, and
A. L.
Kolysko
,
Sov. J. Plasma Phys.
18
,
554
(
1992
).
10.
S. K.
Nam
and
J. P.
Verboncoeur
,
Phys. Rev. Lett.
103
,
055004
(
2009
).
11.
J.-P.
Boeuf
,
B.
Chaudhury
, and
G. Q.
Zhu
,
Phys. Rev. Lett.
104
,
015002
(
2010
).
12.
Y.
Hidaka
,
E. M.
Choi
,
I.
Mastovsky
,
M. A.
Shapiro
,
J. R.
Sirigiri
, and
R. J.
Temkin
,
Phys. Rev. Lett.
100
,
035003
(
2008
).
13.
A.
Cook
,
M.
Shapiro
, and
R.
Temkin
,
Appl. Phys. Lett.
97
,
011504
(
2010
).
14.
J. P.
Anderson
,
M. A.
Shapiro
,
R. J.
Temkin
,
I.
Mastovsky
, and
S. R.
Cauffman
,
IEEE Trans. Plasma Sci.
32
,
877
(
2004
).
15.
A. M.
Cook
,
J. S.
Hummelt
,
M. A.
Shapiro
, and
R. J.
Temkin
,
Phys. Plasmas
18
,
080707
(
2011
).
16.
B.
Chaudhury
,
J. P.
Boeuf
, and
G. Q.
Zhu
,
Phys. Plasmas
17
,
123505
(
2010
).
17.
Q.
Zhou
and
Z.
Dong
,
Appl. Phys. Lett.
98
,
161504
(
2011
).
18.
M. N.
Shneider
and
R. B.
Miles
,
J. Appl. Phys.
98
,
033301
(
2005
).
19.
A. D.
MacDonald
,
Microwave Breakdown in Gases
(
Wiley
,
New York
,
1966
).
20.
G. S.
Nusinovich
,
P.
Sprangle
,
V. E.
Semenov
,
D. S.
Dorozhkina
, and
M. Y.
Glyavin
,
J. Appl. Phys.
111
,
124912
(
2012
).
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