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

 

Parameter

X-rays

Bremsstrahlung

IR, Neutrons, Positrons

Electron beam energy / MeV

12 - 40

8 - 20

12 - 40

Max. bunch charge /pC

0.77

77

77

Max. average beam current /µA

200

1000

1000

Normalized transverse emittance /mm mrad(rms)

3

20

20

Normalized longitudinal emittance /keV ps(rms)

50

140

140

Micropulse duration /ps

2

2

1 - 10

Micropulse repetition rate /MHz

260

13

13

Macropulse duration /ms

0.1 - 40 / cw

0.1 - 40 / cw

0.1 - 40 / cw

Macropulse repetition rate /Hz

1 - 25

1 - 25

1 - 25