Monochromatic backlighting as a laser-fusion diagnostic

Area of Science:

• Plasma Physics
• Nuclear Fusion
• X-ray Optics

Background:

• Laser-driven inertial confinement fusion (ICF) research requires detailed diagnostics of target conditions.
• Characterizing peak compression in ICF targets is challenging due to self-emission and resolution limits.
• Distinguishing target emissions from backlight signals is crucial for accurate imaging.

Purpose of the Study:

• To investigate X-ray radiography techniques for imaging CH-shell targets during laser-driven implosion.
• To address the challenge of discriminating against target self-emission at peak compression.
• To evaluate methods for obtaining high-resolution, selective X-ray images of ICF targets.

Main Methods:

• Utilizing X-ray radiography with a backlight source for CH-shell targets imploded by the Omega Upgrade laser.
• Developing monochromatic imaging techniques using single spectral lines from the backlight.
• Comparing two experimental configurations: X-ray microscope with a flat crystal monochromator and pinhole imaging with a curved crystal monochromator.

Main Results:

• Successful selective imaging of CH-shell targets was achieved using monochromatic X-ray backlight.
• The proposed methods effectively discriminate against target self-emission.
• High-quality images were obtained without requiring a short-pulse backlight beam.

Conclusions:

• Monochromatic X-ray imaging is a viable technique for diagnosing laser-fusion targets.
• This approach overcomes limitations imposed by target self-emission and resolution requirements.
• The study demonstrates practical configurations for obtaining diagnostic images in ICF experiments.