Biological Observation with Laser Plasma X-Rays.

Abstract

Biological observation with soft X-ray microscopy using intense laser-produced plasma X-rays is reviewed. When laser is focused on a solid target at the intensity of 1012-1015W/cm2, plasmas are produced on the solid surface and emit intense soft X-rays. The X-rays are useful for soft X-ray microscopy which draws much attention recently. Soft X-ray microscopy is developed extensively using synchrotron radiation and applied to biological observation. However, for the observation of hydrated biological specimens, synchrotron radiation is not intense enough to circumvent image blurring caused by radiation damage and thermal diffusion. The single shot exposure of laser-produced plasma X-rays will have enough intensity for imaging hydrated biological specimens and will circumvent these problems. Images of hydrated human chromosome fibers obtained with soft X-ray contact microscopy using laser-produced plasma X-rays are shown at the resolution of-10 nm as an example. The results indicate a big potential of laser-produced plasma X-rays for soft X-ray microscopy of hydrated biological specimens.