Spatiotemporal evolution of soft X-ray absorption in an ablated particle cloud created by a 100-fs laser pulse on an aluminum target

Author

Nakano, Hidetoshi ; Okano, Yasuaki ; Oguri, Katsuya ; Nishikawa, Tadashi

Author_Institution

NTT Basic Res. Labs., Kanagawa, Japan

fYear

2005

fDate

22-28 Oct. 2005

Firstpage

625

Lastpage

626

Abstract

This study develops a soft X-ray absorption spectroscopy system for photo-excited material dynamics with one-dimensional spatial resolution. The system consists of a femtosecond-laser-produced plasma X-ray source and a critical illumination system using a KB microscope and has a temporal resolution of approximately 30 ps and a spatial resolution of at least better than 25 μm. Snapshots of expanding aluminum plasma as spatially resolved absorption spectra are successfully obtained. The captured images show the blue shift of the Al L_II,III absorption edge caused by ionization in the ablated plasma. From the amount of soft X-ray absorption, the mean particle density near the target surface 5 ns after the laser pulse irradiation is estimated to be of the order of 10¹⁹ cm^-3.

Keywords

aluminium; high-speed optical techniques; laser ablation; photoexcitation; photoionisation; plasma X-ray sources; plasma diagnostics; plasma production by laser; plasma sources; spatiotemporal phenomena; spectral line shift; 100 fs; 5 ns; Al; Al L_II,III absorption edge; KB microscope; ablated particle cloud; ablated plasma; absorption spectra; aluminum plasma; aluminum target; blue shift; critical illumination system; femtosecond laser pulse; ionization; laser pulse irradiation; one-dimensional spatial resolution; photoexcited material dynamics; plasma X-ray source; soft X-ray absorption; soft X-ray absorption spectroscopy; spatiotemporal evolution; Aluminum; Clouds; Electromagnetic wave absorption; Optical pulses; Plasma density; Plasma x-ray sources; Spatial resolution; Spatiotemporal phenomena; Spectroscopy; X-ray lasers;

fLanguage

English

Publisher

ieee

Conference_Titel

Lasers and Electro-Optics Society, 2005. LEOS 2005. The 18th Annual Meeting of the IEEE

Print_ISBN

0-7803-9217-5

Type

conf

DOI

10.1109/LEOS.2005.1548160

Filename

1548160