Multiple Inner-Shell Electron Excitations (IMAGE) Osaka University Caption (a) Comparison of experimentally observed spectra and theoretical spectra modeled by Los Alamos ATOMIC Code. Spectra generated in zone 2 and 3 are the spectra of Hollow ions. (b) Non-linear growth of X-ray spectra intensities as a function of laser intensity for Al foils with different thickness. Credit Osaka University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.