An Ultraviolet Spectrometer for the Rosetta Orbiter

The ALICE detector is a 2-dimensional MicroChannelPlate photon counting detector by O. Seigmund. It uses a 3-channel wedge-and-strip readout with a dual, solar-blind, photocathode coating of KBr and CsI; dimensions are 35 x 20 mm (spectral x spatial); Nyquist sampling with 5.6 Angstrom resolution.

Signal-to-Noise

Predicted SNR vs. integration time at 700 Angstroms (left), and at 1150 Angstroms (right) for an extended source that fills the slit, across 10 Angstroms of spectral bandwidth, at three brightnesses: 0.01 R, 0.1 R, and 1.0 R.