Extremely brilliant GeV γ-rays from a two-stage laser-plasma accelerator

Area of Science:

• High-energy physics
• Plasma physics
• Laser-driven acceleration

Background:

• Compact ultrashort X/gamma-ray sources are advancing, rivaling synchrotron brilliance.
• Current sources have low efficiency and limited photon output (10^7-8 photons/shot).

Purpose of the Study:

• To present a novel scheme for efficient production of collimated, ultrabright gamma-ray beams.
• To achieve tunable photon energies up to GeV with high efficiency.

Main Methods:

• Focusing a multi-petawatt laser pulse into a two-stage wakefield accelerator.
• Utilizing a high-intensity laser to generate a multi-GeV electron beam in the first stage.
• Directing laser and electron beams into a higher-density plasma region in the second stage.

Main Results:

• Generation of over 10^12 gamma-ray photons/shot with energy conversion efficiency >10% for photons >1 MeV.
• Achieved peak brilliance exceeding 10^26 photons s^-1 mm^-2 mrad^-2 (0.1% bandwidth at 1 MeV).
• Tunable GeV photon energies demonstrated.

Conclusions:

• The novel two-stage accelerator efficiently produces ultrabright, tunable GeV gamma-ray beams.
• This advancement offers significant opportunities for fundamental and applied research.
• The high photon yield and brilliance surpass current limitations of laser-driven sources.