Scientific Instrument HED

The High Energy Density (HED) scientific instrument will be a new, unique platform for experiments combining hard X-ray FEL radiation and the capability to generate matter under extreme conditions of pressure, temperature or electric field using the FEL, high energy optical lasers, or pulsed magnets.

Scientific applications will be studies of matter occurring inside exoplanets, of new extreme-pressure phases and solid-density plasmas, and of structural phase transitions of complex solids in high magnetic fields. In July 2014, the Technical Design report for the HED instrument was published. The HED instrument experiment enclosure construction was completed in July 2014. Construction of the experimental hutches started in late 2015 and continued during 2016. X-ray and optical beamline components commenced in 2016, continued throughout 2017, and we foresee finishing the instrument installation in summer 2018. The first user experiment will start in 2019.

Key features

Bandwidth ΔE/E

10-3  (natural FEL source)

10-4  (standard monochromator)

10-5  (x-ray self-seeding)

10-6  (at 7.1 keV, high-resolution monochromator)

Photon energy range

5 – 20 keV (... – 25 keV *)

*Limited in terms of focusing capability, available photon number of sample, quantum efficiency of detectors


Linear (horizontal)
Circular (future option)

Pulse duration

2–100 fs FWHM (depending on bunch charge)

Pulse energy

of order 1 mJ in SASE mode

Beam size on target

Provided by compound refractive Be lenses (CRLs):

Sub-µm to > 100 µm (CRL 4 in target chamber)

several µm (CRL3 inthe optica hutch)

several 10s of µm (CRL2 in photon tunnel)

several 100s of µm (CRL1 at end of undulators)

of order 1 mm (collimated beam)

Special optics

X-ray Split and delay Line (BMBF contribution)

Standard 4-bounce Si monochromator

High-resolution monochromator at 7.1 keV

Optical lasers

DIPOLE-100X High-energy (100 J-class) long pulse (1-15 ns) laser (HIBEF contribution)
High-intensity (multi-100 TW-class) short pulse (~30 fs) laser (HIBEF contribution)
Pump–probe (mJ to 100 mJ class) short pulse (15 fs – 1 ps) laser