The Superconducting Electron Linear Accelerator

The radiation source ELBE is based on a superconducting linear accelerator that can be operated in high average power mode (quasi continous wave mode, cw). Electrons are preaccelerated in a  250 keV thermionic DC electron gun and prebunched in a two stage RF-buncher section. Main acceleration is accomplished in two 20 MeV superconducting linear accelerator modules operating at 1.3 GHz which are cooled with liquid helium. The RF power is generated by transistor amplifiers,  controled by the low level RF system.

With an electromagnetic chicane between the modules the micropulse duration and energy spread of the beam can be optimized. The accelerator is mainly controled by the control system and the electron beam parameters can be measured by multiple diagnostic tools.

Design Parameters of the ELBE Linac




Electron beam energy / MeV

5 - 40

Max. bunch charge /pC

< 100 *

Max. average beam current /mA


Normalized transverse emittance /mm mrad(rms)

< 20

Normalized longitudinal emittance /keV ps(rms)

< 100

Micropulse duration /ps

1 ... 5 **

Micropulse repetition rate /MHz

<= 26 or Singelpulse

Macropulse duration /ms

0.1 - 40 or cw

Macropulse repetition rate /Hz

1 - 25

*   Superconducting Photoelektron Source - actual bunch charge: < 200 pC

**  Micropulse duration THz: >~ 150 fs