Optical diagnostics on ETA II for X-ray spot size

Gated and streak cameras have been used to look at a high current focused electron beam on a target, and the X-rays produced by that interaction. An optical camera images the optical transition radiation (OTR) from the beam hitting a C target to give focused beam profiles. Blackbody radiation from heavy metal targets is experimentally proven to be dominant, The roll bar technique is used as a thick knife edge to 'image' the X-ray spot produced by the beam-target interaction. The X-ray shadow is converted to visible photons using a scintillator and imaged using a gated optical camera. The scintillator thickness places a limit on the resolution of the diagnostic. Data will be presented from these techniques and compared to an X-ray pinhole camera.