UK director of the Felix partnership

Accelerators are often used to smash particles together or irradiate targets, and sometimes the purpose of this irradiation is to generate other kinds of radiation such as electromagnetic radiation. The other very important reason to use an accelerator is that any charge radiates when subject to acceleration, such as the centripetal acceleration when it is forced to perform a circular path in what is called a synchrotron, and if the speed of the particle is close to the speed of light the radiation is dominantly in the forwards direction. Particle beams can produce very bright and well collimated "laser-like" synchrotron light beams, and in some ways these beams can be much more attractive than regular lasers. For example, the intensity can be extremely high, since the beam of particles can't be damaged or burnt in the way that lasers made from glasses or crystals can. The light pulse duration is related to the particle beam pulse, and this can be very short. Finally, the wavelength of the light is determined by the particle beam energy and the strength of the acceleration, and since these parameters are widely tunable, so is the colour of the light. There are a dozen or so large accelerator based photon sources in Europe that sceintists can visit for experiment, including the UK synchrotron, the Diamond Light Source at Harwell. Many of these sources use the standard circular ring and the synchrotron light is generated by the centripetal force, but some are linear or have straight sections with what is called a line of magnets that cause the electrons to wiggle or undulate on their way through, and these can greatly enhance the light output. One such facility is the FELIX laboratory at the Radboud University, Nijmegen, the Netherlands, which is dedicated to providing intense, tunable and short pulsed infrared light.

The vision of this project is to provide free and easy access for any UK scientist to the FELIX Laboratory. FELIX is a suite of three Free Electron Lasers; unique, flexible, ultrafast light source for mid-infrared and THz spectroscopy. Mid-IR/THz light is important because the photon energy corresponds to many useful phenomena such as the "fingerprint" vibrations that allow identification of molecules, or some spin-flip or magnetic transitions important for memory devices, to name a few. FELIX's set of light characteristics are impossible to obtain simultaneously using standard UK University lab scale equipment, and a large-scale infrastructure, here a free-electron laser (FEL), is crucial for ground-breaking research at the extremes of what is achievable with modern day technology. FELIX provides a powerful means for investigating and manipulating matter in territory that is otherwise impossible to chart, driving it to otherwise unobtainable excited states with unprecedented temporal precision, revealing new functionalities. It is continuously tuneable in a region of the electromagnetic spectrum uniquely suited for driving specific excitations of not only molecules, clusters and collective modes of biologically important proteins, but also electrons in metals and semiconductors. The equipment sharing and user facility access model maximises the size of the UK community, and the provision of a variety of excellent beamlines maximises its diversity.

In this project we aim to understand better the needs of the UK research community, and help them to gain access to this world-leading facility. At the same time we aim to drive developments at FELIX that will meet the UK Community needs of the future.