The US National Science Foundation (NSF) has awarded Cornell University $18 million to begin developing a high-brilliance, high-current Energy Recovery Linac (ERL) synchrotron radiation X-ray source.
All existing hard X-ray synchrotron radiation facilities are based on storage rings. Equilibrium emittance considerations limit the X-ray brilliance that is practically attainable and the ability to make short intense X-ray pulses. In an ERL the electron bunches are not stored; rather, electron bunches with very low emittance are created then accelerated by a superconducting linac.
After one circuit around a transport loop, where the X-rays are produced, the electron energy is extracted back into the radio-frequency (RF) field of the linac and used to accelerate new bunches. The energy-depleted bunches are dumped.
The beams from ERLs are predicted to be around 1000 times better in terms of brightness, coherence and pulse duration than current X-rays. They will enable investigations that are impossible to perform with existing X-ray sources.
The ERL is based on accelerator physics and superconducting microwave technology in which Cornell’s Laboratory of Elementary Particle Physics is a world leader. The NSF award to Cornell will fund the prototyping of critical components of the machine. The design team, led by Cornell’s professors Sol Gruner and Maury Tigner, has already almost completed the prototype design; scientists from Jefferson Laboratory worked with Cornell on the initial design. Prototype construction and testing should finish in 2008. Cornell then will seek funding for a full-scale ERL facility as an upgrade of the present synchrotron radiation facility, the Cornell High Energy Synchrotron Source (CHESS), which is based on the Cornell Electron Storage Ring (CESR).
