Transition radiation is emitted as the ultra-short electron or positron bunches pass through a one-micron thick titanium foil oriented at 45 degrees relative to the beam.
Non-coherent optical transition radiation (OTR) is viewed by a CCD camera for measurement of the transverse beam profile.
We have various OTR locations in the FACET beamline.
The typical OTR installation comprises a stepper motor and a "ladder" that allows a choice of targets to be inserted into the beam. We've tried various designs of ladders and installed many different materials on them. We can install the material of your choice on a ladder if you wish to study what happens when a material is inserted into the beam. Our standard target for OTR is 500 micron thick polished titanium.
A typical installation may also include a YAG screen for visualization of low charge density beams.