Light source device, method for manufacturing the same and filament

摘要

A filament showing high radiation characteristics and hardly suffering from disconnection and film separation is provided by using a high melting point metal compound such as tantalum carbide or hafnium carbide. For example, as the filament, a filament comprising a tungsten base material 30, a tantalum or hafnium layer 31 coating the tungsten base material 30, and a tantalum or hafnium carbide layer 32 coating the layer 31 is used. High adhesion is obtained at the interface of the layers of tungsten and tantalum or hafnium.