Ripe for detecting photons and other particles, the IRD AXUV 100GX absolute X-ray photodiodes possess known active silicon thicknesses and 100% internal quantum efficiency, making possible absolute measurement of X-ray flux with energies 100 keV and beyond. The photodiodes feature a 10 mm x 10 mm square active area with room-temperature operation and a small detector footprint. They require no external voltage for operation. A nitride-oxide front window provides up to a Giga rad of radiation hardness, which is allegedly 10,000 times greater than standard PIN silicon photodiodes. OPTO DIODE CORP., Newbury Park, CA. (805) 499-0335.