Electromagnetic radiation attenuating and scattering member with improved thermal stability

Abstract

The present invention provides a thermally stable reference member comprising, at least one radiation attenuating element and at least one radiation scattering element. The radiation attenuating element comprising at least one aperture for transmission of radiation therethrough. The attenuating and scattering elements placed in series so that radiation transmitted through the reference member passes through each of the attenuating and scattering elements. The attenuating and scattering elements of the reference member may further comprise a thermally stable mount to hold the elements in a selected position relative to each other, and in relation to an instrument, or the elements may be bonded together. The radiation attenuating element may be comprised of a material selected from the group consisting of INVAR, tungsten, brass, and a material substantially non-transparent for incident radiation, and the radiation scattering element may be comprised of a radiation scattering material selected from the group consisting of opalescent glass, SPECTRALON, PTFE, ZERODUR, fused silica, quartz, sapphire, diamond, and a transparent material with essentially low thermal expansion.

Dependencies are inferred from the claim text.