Comparison of on-shot, in-tank, and equivalent-target-plane measurements of the OMEGA Laser System focal spot

Abstract
The newly developed full-beam-in-tank (FBIT) diagnostic has the capability to characterize multiple beamlines in the target chamber. In addition to measuring multiple beams, we can obtain measurements of the step-by-step changes to achieve smoothing by spectral dispersion (SSD), the SSD kernel, and SSD synchronization. Since other existing diagnostics are all located upstream of the target chamber, this diagnostic can be used to explore a propagating beam through the final optics assembly. In this work, we investigate current discrepancies between laser diagnostics and experimental results by comparing results of on-shot direct measurements using FBIT and the equivalent-target-plane diagnostic.