The electron beam in the MAX IV linear accelerator can be tailored for special purposes, such as short pulses (10 fs), double pulses with a few hundred fs separation or ultra-low emittances. This is fundamental for applications such as Free Electron Laser or Plasma wake field acceleration. To achieve these custom made pulses precise laser pulse shaping is needed.
The process defining much of the properties of the electron pulses come from the laser pulses impinging on the photo cathode in the 3 GHz RF gun at the start of the acceleration process. By careful compression, stacking, timing and pointing a 260 nm laser pulse, together with the 100 MV/m Electric field in the gun it is possible to define the electron beam properties.