Wakefield Accelerator

About Wakefield Accelerator

• Wakefield accelerator is a plasma-based accelerator that uses plasma waves to accelerate charged particles over a short distance.
• In contrast, conventional accelerators, such as the 27-km Large Hadron Collider (LHC) in Europe, use powerful magnets and electric currents to accelerate particles.
• Plasma: It is an ionized gas in which electrons and positively charged ions can move independently.
• Working Mechanism:
  • Driver: A strong driver is sent through the plasma to create the wakefield.
    • The driver can be either a laser pulse or an ultra-relativistic electron beam, making the acceleration laser-driven or particle beam-driven.
  • Electron Displacement: As the driver passes through the plasma, it pushes the lighter plasma electrons away from its path, while the heavier ions remain nearly stationary.
  • Restoring Force: After the driver passes, the ions pull the displaced electrons back towards the axis.
  • Wakefield Formation: The electrons overshoot and move back and forth, creating an oscillating density wavebehind the driver.
    • The electric fields of this wave are called wakefields.
  • Particle Injection: Other electrons are injected into the wakefield at the right point so that they can interact effectively with the moving electric fields.
  • Acceleration: The injected electrons surf the moving electric fields, drawing energy from the plasma wave and gaining high energy over a short distance.
• Key Advantage:
  • High Acceleration Gradient: It can produce an electric field gradient of up to 100 GV/m (Gigavolts per metre), allowing particles to gain much more energy over each metre.
    • This is about 1,000 times stronger than conventional radio-frequency accelerators, which achieve around 50–100 MV/m.
  • Miniaturisation: Higher energy gain per metre can reduce accelerator size from kilometres to a few metres or tabletop scale.
  • Cost-Efficiency: Shorter acceleration paths can reduce infrastructure, manufacturing, and operational costs.