ELBE Center for High-Power Radiation Sources
ELBE is a world-wide unique instrument providing compact, accelerator-driven photon and particle sources. The variety of secondary radiation being offered extends from high-energy gamma rays, to infrared and THz radiation, to neutron, positron and electron beams.
ELBE is operated as a user facility, providing more than 50% of the beamtime to external user groups.
The core of the ELBE Center for High-Power Radiation Sources is the 40 MeV superconducting electron accelerator ELBE (Electron Linear accelerator with high Brilliance and low Emittance), generating a variety of secondary radiation beams like MeV Bremsstrahlung, neutrons and positrons and driving multiple photon sources comprised of two free electron lasers (called FELBE) and a superradiant THz source (called TELBE). Roughly 40% of the total beamtime at ELBE is given to the IR and THz beams.
The FELBE FELs are the only FELs in Europe providing ultrashort pulses at a continuous high repetition rate (13 MHz). The two FELs of FELBE provide continuous tunability over a spectral range of 5 µm - 250 µm (U37 : 5 µm - 40 µm, U100 : 20 µm - 250 µm) with a bandwidth of ~0.4 - 3% and a maximum average power up to tens of Watts, corresponding to pulse energies of a few µJ. The ultrashort pulsewidth scales with the wavelength, ranging from sub-ps to a few tens of ps, resulting in a maximum peak power within each pulse of ~ 1 MW and fields up to MV/cm. The high repetition rate (13 MHz) and high average power enable exceptional signal-to-noise and data statistics, but additional time structures such as a macropulse (burst) mode or lower repetition rates by pulse-picking are also available.
The THz user laboratory was completed and brought into operation for early users in August 2016. The two THz sources (diffraction and undulator) can be operated in parallel and generate carrier-envelope phase (CEP) stable single-cycle, and tuneable multi-cycle, THz pulses that are transported in two separate optical beamlines into the laboratory. A novel pulse-resolved data-acquisition system in combination with a femtosecond arrival-time monitor were developed, enabling time-resolved experiments with sub-THz cycle temporal resolution of better than 12 fs. The high repetition rate allows pulse sorting and signal averaging, providing high sensitivity and dynamic range for both time- and frequency-domain measurements. Several experimental techniques for probing THz field driven dynamics in matter have been implemented and successfully demonstrated in close collaboration with leading international groups, examples being transient Faraday/MOKE (magneto-optic Kerr effect), or THz-emission spectroscopy.
All ELBE sources including FELBE and TELBE are open to users through an online portal (GATE). There are two calls for Beamtime Proposals per year with deadlines in the spring and in the fall.
The next deadline for the submission of beamtime applications is September 18th, 2023.
User access to the ELBE - Center for High-power Radiation Sources is managed in line with the recommendations of the European Charter for Access to Research Infrastructures. Beamtime proposals are reviewed by an external science advisory committee. It is quality-based and relies on a peer-review procedure based on research proposals. The primary selection criterion is scientific excellence. Among scientifically equally ranked proposals, priority is given to users from countries without national FEL and from EU-13 states, to PhD students, and to women PIs.
ELBE as a whole is operated 24 h, 7 days/week, beamtime is granted in units of 12 hours from 6:00 to 18:00 and from 18:00 to 6:00.