Bright table-top x-ray sources using laser wakefield acceleration

The aim of this project is to develop very bright x-ray sources based on the technique of laser wakefield acceleration. This can all be achieved in a compact, university-scale laboratory as laser wakefield acceleration can produce high energy electron beams ( ~ 1 GeV) in just 1 cm, compared with the 100s of metres required using conventional techniques. In laser wakefield acceleration electrons are accelerated in a plasma wave generated by a very intense laser pulse. As the electrons are accelerated in the wakefield they also oscillate, generating very bright x-rays with properties similar to or even surpassing those of conventional synchrotron radiation sources. In particular, the ultra-short nature of these betatron x-rays opens up the possibility of ultra-fast time-resolved studies that are not possible with conventional synchrotron radiation. Such bright x-rays have a multitude of uses in science and technology, being used to study the microscopic properties of matter in areas as diverse as biology, drug development and materials science. Bringing these bright x-ray sources down to a university-laboratory-scale could significantly increase and broaden access to these important tools for science and discovery.The project will study a number of methods that can manipulate the trajectories of the electrons within the wakefield itself to control and enhance the properties of the x-rays generated. Techniques based on laser pulse shaping, plasma profile shaping and the use of multiple laser pulses will be investigated both numerically, using state-of-the-art computational simulations, and on experiments at a number of world leading laser facilities around the world. Access to the multi-TW laser facilities at the Rutherford Appleton Laboratory, Lund University and the University of Michigan will enable these techniques to be studied for a range of laser parameters. The project builds on the strong track record of the Imperial College Laser-Plasma group in the field of laser wakefield acceleration and radiation generation, providing us with new tools for the study of these extremely bright, ultra-bright laser produced x-rays.

The development of bright high quality x-ray sources based on laser wakefield acceleration will have a direct impact on current users of bright x-ray sources. These include both a broad range of industrial and scientific users, for example at the Diamond light source users working in the areas of structural biology, material science, chemistry, environmental science, oceanography, archaeology, earth science, and even the fields of art, history and cultural heritage use bright x-rays. By developing light sources with comparable or complementary properties, but on a university or industrial laboratory scale, we will open up the possibility of wider access to bright x-rays, for example allowing techniques such as phase contrast imaging or lens-less imaging to be performed in-house. The majority of potential users of these bright x-rays will be from academic institutions, however the potential impact that research undertaken by such a wide range of scientists will be very broad, for example researchers using such sources in the field of structural biology could make discoveries that affect the development of new drugs that will impact wider society.