Petapascal Pressure Driven by Fast Isochoric Heating with a Multipicosecond Intense Laser Pulse

Area of Science:

• Plasma Physics
• High-Energy-Density Physics
• Laser-Matter Interactions

Background:

• Fast isochoric laser heating is a method for creating ultrahigh-energy-density (UHED) states using relativistic laser pulses.
• Achieving UHED states is crucial for fundamental physics research and inertial confinement fusion.
• Conventional methods often require substantial energy input and complex target configurations.

Purpose of the Study:

• To demonstrate an efficient fast isochoric heating scheme for creating UHED states.
• To investigate the role of externally applied magnetic fields in enhancing heating efficiency.
• To achieve a UHED state with significantly reduced laser energy compared to existing methods.

Main Methods:

• Utilized a kilojoule-class petawatt laser system for multipicosecond pulse delivery.
• Employed externally applied kilotesla magnetic fields to guide fast electrons.
• Heated a compressed dense plasma core to achieve the UHED state.
• Conducted two-dimensional particle-in-cell simulations to analyze heating mechanisms.

Main Results:

• Achieved an ultrahigh-energy-density state of 2.2 Petapascals (PPa).
• Required only 4.6 kilojoules (kJ) of laser energy, an order of magnitude less than conventional implosion schemes.
• Demonstrated efficient heating of the dense plasma core.
• Simulations confirmed the critical role of diffusive heating from the laser-plasma interaction zone.

Conclusions:

• Fast isochoric laser heating, assisted by magnetic fields, is an efficient pathway to UHED states.
• This method offers a significant energy reduction compared to traditional approaches.
• Diffusive heating is a key mechanism for efficient UHED state creation in this scheme.