Prospects for a 4th Generation Light Source for the UK

A 4th Generation Light Source (4GLS) forms a major part of the new CASIM (Centre for Accelerator Science, Imaging and Medicine) project that has been proposed to be based at Daresbury Laboratory. Such a light source is envisaged to contain 3 free electron lasers (FELs) that are integrated with a highly optimised low energy synchrotron radiation source. The light source will be optimised to cover the photon energy range of 5 to 100 eV as well as being designed to host a cavity based FEL that would operate in the UV region. A second, linac based, infrared FEL would be placed in the same building thus enabling pump-probe experiments to be carried out with,state, of the art photon flux and brightness. The third FEL would not initially be a user facility but would be a linac based SASE FEL research project with the aim of producing ultra high brightness light in the VUV/SXR region. The primary source of 5 to 100 eV light could either be a storage ring or an energy recovery linac. Both options are presently being studied and a choice will be made by the Autumn of 2001. This paper describes the present concept for the 4GLS project and details the current status of the designs