  Characterizations of transverse profiles for low-power beams in the
accelerators of the proposed linear colliders (ILC and CLIC) using imaging
techniques are being evaluated. Assessments of the issues and limitations for
imaging relativistic beams with intercepting scintillator or optical transition
radiation screens are presented based on low-energy tests at the Fermilab A0
photoinjector and are planned for the Advanced Superconducting Test Accelerator
at Fermilab.
