2026-10-15T01:33:46Z https://www.scidb.cn/oai

10.57760/sciencedb.45562 2026-08-20T16:20:47Z

2026-08-20 Tunable Betatron X-rays via Plasma Density Control with Ionization Injection for Multi-Material Imaging doi:10.57760/sciencedb.45562 en This study demonstrates two reproducible critical-energy (Ec) operating points of laser-driven betatron radiation selected by plasma density and examines the coupled imaging consequence of spectral hardening and enlarged transverse oscillations. Experiments with the SULF-1PW laser used densities from 2×1018 to 8×1018cm−3. Photon yield was measured at four densities and remained of order 1012 photons/sr within the reported variations. Stable Ec values, however, were established only at 2×1018 and 6×1018cm−3: 15.5±3.8 and 25.6±3.9 keV, respectively. PIC-derived trajectories show an increase of the RMS betatron amplitude proxy from 6.2 to 17.2 µm at the higher-density point, despite dephasing-induced loss of final electron energy. The harder spectrum improves penetration of an aluminum-alloy assembly, whereas the lower-density condition provides stronger edge enhancement in Teflon and a plant specimen. Geant4 calculations using the measured spectra and PIC derived source-size proxies reproduce the observed contrast trend. The results establish an operational two mode imaging strategy without claiming unmeasured Ec values at the other two density conditions. plasma; x-ray; lwfa 郭航 李松 RESTRICTED dataset Science Data Bank