Year: 2004
Type: article
Abstract: The 4GLS project is a novel next generation solution for a UK national light source proposed to be sited at Daresbury.It is based on an energy recovery linac (ERL) operating at high average beam currents up to 100mA and with compression schemes producing pulses in the 10-100 fs range.This would provide a unique spontaneous emission source with high average brightness output both from undulators and bending magnets.In addition to this operating regime a high peak current mode would also be possible at lower duty cycle, enabling a high gain FEL amplifier to generate XUV radiation.Longer wavelength FELs are also planned.This challenging accelerator technology, new to Europe, necessitates a significant R&D programme and as a major part of this a low energy prototype, the ERLP, is being constructed at Daresbury.The paper summarises the ERLP design specification, describes the component solutions adopted and explains the 4GLS project status and plans. THE 4GLS PROJECTThe 4GLS project is a proposed national light source for the UK, optimised for the low energy user community and exploiting 4 th generation concepts in order to extend the capabilities of existing 3 rd generation designs.It abandons the traditional electron storage ring solution and replaces this with an electron linac, taking advantage of the combination of transverse and longitudinal brightness that can thereby be achieved.Use of such a linac also permits incorporation of advanced free electron laser (FEL) devices to supplement the spontaneous emission sources.This multi-source concept originated at Daresbury in 2001 and has been developed significantly since then [1,2,3].A key feature of such a light source is the need to provide transverse brightness competitive with that at the 3 rd generation facilities: a combination of low emittance and high beam current that implies a high brightness injector and an average beam current capability of at least 100mA.This latter requirement necessitates adoption of an Energy Recovery Linac (ERL) solution, as successfully demonstrated at both the Jefferson [4] and JAERI [5] Laboratories.A novel feature of the Daresbury proposal is that the electron return path, needed to return the beam for deceleration in a second pass through the linac, is also utilised to provide a range of photon sources, including various undulators and FELs.An ERL is no longer restricted by the dynamic equilibrium properties of a storage ring.Its high energy beam properties are determined by those of its injector, together with the ability then to preserve or manipulate
Authors: M.W. Poole, Elaine A. Seddon
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: Office of Science
OpenAlex ID: W2186325227