Cross-facility absolute charge calibration of scintillating screens for laser wakefield accelerated beam diagnostics.

Scintillation screens are widely used to diagnose high-charge density, low-average current electron beams from laser wakefield accelerators (LWFAs). However, the absolute response between emitted photons and electron charge has only been calibrated at a limited number of facilities, and there have been discrepancies between these calibrations. In this report, we comprehensively revised the absolute charge calibration of two high relative brightness scintillating screens of LANEX Regular (Carestream) and PI200 (Mitsubishi) by employing the high-brightness photoinjector at the National Synchrotron Radiation Research Center (NSRRC), which provides electron beams with variable charges (50-350 pC per pulse) and energies (26.

Seeding of a soft-x-ray laser in a plasma waveguide by high harmonic generation.

A strongly saturated waveguide-based optical-field-ionization soft-x-ray laser seeded by high harmonic generation was demonstrated for Ni-like Kr lasing at 32.8 nm. Compared with the same laser seeded only with spontaneous emission, seeding with high harmonics yields much smaller divergence, enhanced spatial coherence, and controlled polarization.

Single-shot soft-x-ray digital holographic microscopy with an adjustable field of view and magnification.

Single-shot digital holographic microscopy with an adjustable field of view and magnification was demonstrated by using a tabletop 32.8 nm soft-x-ray laser. The holographic images were reconstructed with a two-dimensional fast-Fourier-transform algorithm, and a new configuration of imaging was developed to overcome the pixel-size limit of the recording device without reducing the effective NA.