A new-type analyzer for measurement of energetic neutral atoms (ENAs) in an energy range of 4–40 keV is described. Incoming ENAs are ionized by electron stripping at passage of an ultrathin carbon foil. After post-acceleration (by 3 kV), the particles are guided to a time-of-flight (TOF) section over a wide energy-per-charge bandwidth by means of electrostatic deflection without any potential sweeping for electrodes. Then, their velocity is measured by the TOF technique, with which species can also be identified, because the particle energies are limited to a certain range by the electrostatic deflector and acceleration upon entering the TOF section. A unique feature in the present analyzer is in the rejection method of extreme ultraviolet (EUV) contamination. In contrast to conventional usage of serrated electrodes for EUV attenuation, one of the electrostatic deflection plates is machined to be so flat that EUV photons are guided to a photon trap regardless of wavelength. The TOF device can also be used in a coincidence mode for noise suppression. The present instrument was flown on a sounding rocket, and has successfully measured ENAs precipitating into the low-latitude upper atmosphere from the magnetosphere.

1.
D. J.
Williams
,
E. C.
Roelof
, and
D. G.
Mitchell
,
Rev. Geophys.
30
,
183
(
1992
).
2.
M.
Gruntman
,
Rev. Sci. Instrum.
68
,
3617
(
1997
).
3.
S.
Orsini
,
I. A.
Daglis
,
M.
Candidi
,
K. C.
Hsieh
,
S.
Livi
, and
B.
Wilken
,
J. Geophys. Res. [Space Phys.]
99
,
13489
(
1994
).
4.
T. E. Moore, M.-C. Fok, J. D. Perez, and J. P. Keady, in Cross-Scale Coupling in Space Plasmas, Geophys. Monograph 93, edited by J. L. Horowitz et al. (AGU, Washington, DC, 1995), pp. 37–46.
5.
K.
Asamura
,
T.
Mukai
,
Y.
Saito
,
Y.
Kazama
, and
S.
Machida
,
Geophys. Res. Lett.
26
,
33
(
1999
).
6.
R. L.
Rairden
,
L. A.
Frank
, and
J. D.
Craven
,
J. Geophys. Res. [Space Phys.]
91
,
13613
(
1986
).
7.
E. E.
Scime
,
H. O.
Funsten
,
D. J.
McComas
,
K. R.
Moore
, and
M. A.
Gruntman
,
Opt. Eng. (Bellingham)
33
,
357
(
1994
).
8.
C. J.
Pollock
,
K.
Asamura
,
J.
Baldonado
,
M. M.
Balkey
,
P.
Barker
,
J. L.
Burch
,
E. J.
Corpella
,
J.
Cravens
,
G. D.
Dirks
,
M.-C.
Fok
,
H. O.
Funsten
,
M.
Grande
,
M.
Gruntman
,
J.
Hanley
,
J.-M.
Jahn
,
M.
Jenkins
,
M.
Lampton
,
M.
Marckwordt
,
D. J.
McComas
,
T.
Mukai
,
G.
Penagor
,
S.
Pope
,
S.
Ritzau
,
M. L.
Schattenburg
,
E.
Scime
,
R.
Skoug
,
W.
Spurgeon
,
T.
Stecklein
,
S.
Storms
,
C.
Urdiales
,
P.
Valek
,
J. T. M.
Van Beek
,
S. E.
Weidner
,
M.
Wüest
,
M. K.
Young
, and
C.
Zinsmeyer
,
Space Sci. Rev.
91
,
113
(
2000
).
9.
H. O.
Funsten
,
D. J.
McComas
, and
B. L.
Barraclough
,
Opt. Eng. (Bellingham)
32
,
3090
(
1993
).
10.
W. Bernstein, R. L. Wax, N. L. Sanders, and G. T. Inouye, in Small Rocket Instrumentation Techniques (North-Holland, Amsterdam, 1969), pp. 224–231.
11.
D. J.
McComas
,
H. O.
Funsten
,
J. T.
Gosling
,
K. R.
Moore
,
E. E.
Scime
, and
M. F.
Thomsen
,
Opt. Eng. (Bellingham)
33
,
335
(
1994
).
12.
A.
Bürgi
,
M.
Oetliker
,
P.
Bochsier
, and
J.
Geiss
,
J. Appl. Phys.
68
,
2547
(
1990
).
13.
K. Asamura, T. Mukai, Y. Saito, Y. Kazama, and S. Machida, ISAS Res. Note No. 607, ISAS, Japan, 1997.
14.
W.
Meckbach
,
G.
Braunstein
, and
N.
Arista
,
J. Phys. B
8
,
L344
(
1975
).
15.
K. C.
Hsieh
,
E.
Keppler
, and
G.
Schmidtke
,
J. Appl. Phys.
51
,
2242
(
1980
).
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