Compact x-ray microscope for the water window based on a high brightness laser plasma source

Area of Science:

• Optics and photonics
• Biomedical imaging
• Laser-driven X-ray microscopy

Background:

• Traditional X-ray microscopy faces limitations in resolution and speed.
• The water window (2.4-4.4 nm) is crucial for imaging biological specimens in their native state.
• High-brightness X-ray sources are needed for efficient microscopy.

Purpose of the Study:

• To develop and characterize a laser plasma-based X-ray microscope for the water window.
• To achieve high photon flux and resolution for biological imaging applications.
• To reduce exposure times for faster microscopic analysis.

Main Methods:

• Utilized a high-average power laser system for plasma generation.
• Employed nitrogen Lyα line emission at 2.478 nm as the X-ray source.
• Used multilayer condenser optics to focus X-rays onto the sample.

Main Results:

• Achieved a brightness of 7.4 x 10^11 photons/(s x sr x μm^2) at 90 W laser power.
• Obtained 10^6 photons/(μm^2 x s) in the object plane with 0.3% reflectivity condenser.
• Resolved 40 nm lines with a 60-second exposure time at 60 W laser power.

Conclusions:

• The developed laser plasma X-ray microscope offers high performance for water window imaging.
• Potential for further improvement in speed (20 s exposure) with enhanced optics and higher laser power (130 W).
• This technology advances high-resolution, rapid X-ray microscopy for biological sciences.