Table 1: Used optical data.

Energy intervall [eV]	Reference
10 000-51.57	Lynch & Hunter (1996)
51.57-26.0	interpolation (see text)
26.-5	Moravec et al. (1976)
3.5-1.55	CRC (1998)
1.55-0.0124	Ordal et al. (1988)
0.0124-0.00124	extrapolation (see text)