Laser-Accelerated Ions from a Shock-Compressed Gas Foil.

Area of Science:

• Plasma Physics
• Laser-Matter Interaction
• Particle Acceleration

Background:

• Laser-driven ion acceleration is crucial for various applications.
• Controlling ion beam properties requires precise target design.
• Existing methods face limitations in energy and focus.

Purpose of the Study:

• To investigate energetic laser-ion acceleration from a tailored gas target.
• To explore the transition between different acceleration regimes.
• To understand the underlying physics of magnetic vortex acceleration.

Main Methods:

• Utilized a near solid density hydrogen gas jet compressed by colliding hydrodynamic shocks.
• Employed ultraintense laser pulses interacting with the compressed gas target.
• Conducted a density scan to observe acceleration regime transitions.
• Performed three-dimensional simulations to analyze electron dynamics and Z-pinch formation.

Main Results:

• Demonstrated energetic laser-ion acceleration from the tailored gas target.
• Observed a transition from target normal sheath acceleration (low-energy, wide-angle beams) to magnetic vortex acceleration (focused beams with high-energy halo).
• Simulations confirmed Z-pinch formation driven by laser wakefield accelerated electrons, leading to ion acceleration via space charge fields and Coulombic repulsion.

Conclusions:

• Tailored, near solid density gas targets enable efficient laser-ion acceleration.
• Magnetic vortex acceleration offers a pathway to focused, high-energy ion beams.
• The study provides insights into the physics of laser-driven Z-pinches and subsequent ion acceleration.