Energy Range
12.03 and 11.99 eV
Wavelength
103.2 and 103.6 nm
Effective Area
1.85 cm2 at 103.5 nm (11.98 eV)
Energy Resolution
<0.07 nm at 103.5 nm (λ/Δλ >1500)
The sole observational instrument is a suite of four modified Rowland-Circle spectrographs with parallel channels. Each is equipped with a 6.2 cm × 3.7 cm off-axis parabolic mirror and a toroidal diffraction grating, a flight-proven variant similar to that used in FUSE, but with a lower spectral resolution in order to make it more sensitive to diffuse sources. The optical surfaces uses Al+LiF coatings. The detectors are micro-channel plates. Each of the four spectrographs are offset from each other by 60′ along the slit width direction.
