Extreme Ultraviolet Spectrometer (EUV)

Charles W. Hord, Principal Investigator
University of Colorado

• Study the composition and structure of the upper Jovian atmosphere.

• Determine the loss rates of volatile gases from the Galilean satellites.

• Examine the physical processes occurring in the Io plasma torus.

• Do follow up studies to the Voyager UVS discoveries.

• The EUV is an objective grating spectrometer with a mechanical collimator.

• There is a concave dispersion grating that focuses extreme ultraviolet via a single reflection onto a detector consisting of a photocathode, microchannel plate electron multiplier, and an anode array.

• The EUV is a modified Voyager spare Ultraviolet Spectrometer with an electrical interface to adapt it to the Galileo command and data bus.

• The EUV has a 20 cm focal length and an aperture of 4.0 x 6.0 cm.

• The EUV covers 54 to 128 nm in 128 contiguous intervals of 0.59 nm.

• The EUV field of view is 0.17 Deg. FWHM in the dispersion direction and about 0.87 Deg. in the cross-dispersion direction.

• The wavelength resolution of the EUV is 3.5 nm for extended sources and 1.5 nm for point sources.

Instrument Mass:	12.23 Kg
Power Consumption: --Instrument	6.65 W
Microprocessor:	1802 type
ROM/RAM:	0 b/1.3 Kb
Size : --EUV Channel --Logic Module	44.3 x 16.9 x 14.9 cm 27.9 x 17.8 x 6.4 cm
Thermal Range: --Operating (GLL3-210) ----EUV Logic Module ----EUV Sensor --Non-operating (GLL 3-210) ----EUV Logic Module ----EUV Sensor	5 to 50 Deg. C -20 to 30 Deg. C 5 to 50 Deg. C -20 to 35 Deg. C
Instrument Modes: --Encounter --Cruise	Off POR On