FELIX provides infrared and THz radiation with energies corresponding to low energy vibrational, spin and electronic excitations in solids and molecules in solution and gas phase. Therefore, FELIX is ideally suited to study in detail their ground state properties. In this low energy region no other powerful, tunable and pulsed sources exist. At FELIX there are four free electron laser beamlines FEL-1 (30 – 150 μm), FEL-2 (3-45 μm), FELICE (5-100 μm) and FLARE (100-1500 μm), which produce microsecond-duration macropulses consisting of a train of picosecond micropulses. With this suite of free electron lasers FELIX offers the largest wavelength tuning range in a single facility to its user community. Primary applications are found in areas benefitting from the wide tunability, high brightness or the high fluence of the FELIX sources. Research projects include systems such as (bio) molecules, clusters and complexes as well as semiconductors, metals and magnetic materials, using various techniques (transmission, absorption, mass spectrometry, ionization spectroscopy etc.). The information obtained may serve as a fingerprint to identify species, determine molecular structure, probe quantum coherence, flip spins, identify chemical bonds etc. Both the radiation as well as all advanced additional infrastructure (spectrometers, molecular beam apparatus, ion traps, detectors, etc.) is provided to users for research.
The FELICE (Free Electron Laser for Intra-Cavity Experiments) beam line is the only FEL beam line in the world dedicated to intra-cavity experiments enabling optical studies on molecules and clusters throughout the infrared spectral region with unprecedented photon flux. With its instrumentation the FELIX Laboratory makes major contributions to the following research themes:
(i) Atomic and Molecular Physics
(ii) Condensed Matter Physics
(iii) Optical and Laser Physics
(vi) (Time-resolved, non-linear) Spectroscopy in high magnetic fields
A world-wide unique feature is that FELIX radiation can be combined with the high magnetic fields of the adjacent High Field Magnet Laboratory (HFML) which allows the study of matter in high magnetic fields and under intense infrared and THz radiation. With the recently commissioned full optical beamline, infrared/THz experiments at magnetic fields up to 33 T with picoseconds time-resolution have become possible. A combined HFML-FELIX research team has been formed to develop and exploit the unique research opportunities offered by this new combination of instrumentation.
FELIX was originally developed at the FOM institute Rijnhuizen and has recently been moved to the Radboud University. It has a lasting reputation as an excellent, internationally recognized facility, as exemplified e.g. by the Evaluation Reports of 2008 and 2011. The FELIX Laboratory is dedicated to research by both in house scientists as well as external users, resulting in more than 40 refereed journal publications per year including several in high profile journals. The fact that FELIX was conceived and functions exclusively as a research tool makes it a highly valued research facility, providing a hospitable and very flexible research environment. The embedding within the Radboud University has created a very stimulating and diverse research environment that significantly contributes to the strength of the facility