OPTICAL IMAGING CHAMBER FOR X-RAY ASTRONOMY

The light emitted by electron avalanches in a parallel plate chamber c an be used to image the tracks of photoelectrons liberated by the inte raction of an incident-x-ray with the gas filling the chamber. The dif fering morphologies of photoelectron tracks and high-energy charged pa rticle tracks can be used for background rejection. The initial direct ion (before scattering) of the liberated photoelectron also contains i nformation about the polarization of the incident radiation. We have b uilt a small test chamber with which we have imaged photoelectron trac ks using an intensified CCD camera. Our results show that optical imag ing could be used in a hard x-ray imaging polarimeter useful for astro nomy.