Table 1 Specification and performance of LEPi

Energy range

< 0.01–25

keV/q

Energy resolution

0.16 @ 0.01 keV/q

\(\Delta E / E\)

0.13 @ 12 keV/q

\(\Delta E / E\)

Analyzer constant

5.0

Inner dome radius

41.5

mm

Electrode in ESA

Outer dome radius

45.5

mm

Electrode in ESA

Mass discrimination

\(\hbox {H}^{+}\), \(\hbox {H}_{2}^{+}\)/\(\hbox {He}^{++}\), \(\hbox {He}^{+}\)

\(\hbox {N}^{++}\)/\(\hbox {O}^{++}\), \(\hbox {N}^{+}\)/\(\hbox {O}^{+}\)

\(\hbox {N}_{2}^{+}\)/\(\hbox {NO}^{+}\)/\(\hbox {O}_{2}^{+}\)

Post-acceleration potential

− 4.9

kV

Foil potential

Length of TOF drift path

26

mm

FOV

310 \(\times\) 4.5

deg × deg

FWHM

Angle response of azimuthal channels

16.0

deg

FWHM, wide channel

4.3

deg

FWHM, narrow channel

Separation of azimuthal channels

22.5

deg

Geometric factor

1.7 @ 0.01 keV/q

10\(^{-3}\) \(\hbox {cm}^{2}\) str keV/keV/channel

Wide channel

1.4 @ 12 keV/q

10\(^{-3}\) \(\hbox {cm}^{2}\) str keV/keV/channel

Wide channel

0.40 @ 0.01 keV/q

10\(^{-3}\) \(\hbox {cm}^{2}\) str keV/keV/channel

Narrow channel

0.32 @ 12 keV/q

10\(^{-3}\) \(\hbox {cm}^{2}\) str keV/keV/channel

Narrow channel

Number of energy steps

32

Number of mass bins

1–8

Normal mode, commandable

1–509

TOF mode, commandable

Number of azimuthal bins

1–15

Normal mode, commandable

1

TOF mode

Number of spin phase bins

1–16

Normal mode, commandable

1–4

TOF mode, commandable

Time resolution

1–65,536

Satellite spin (nominal spin period: 8 s)

Full 3D observation both for normal and TOF modes commandable

Dead time

1

ms/energy step

Commandable

Sensor size

235 \(\times\) 235 \(\times\) 362

mm \(\times\) mm \(\times\) mm

Sensor mass

6.94

kg

Power consumption

23.8

W

Primary side