Dielectric Laser Accelerators (DLA)

Accelerating gradient (energy/distance) in modern RF particle accelerators is reaching a limit based on the damage threshold of metal accelerator structures. Dielectric-based accelerators hold promise to increase achievable gradients as a result of higher material damage thresholds, reducing overall length of systems. By driving acceleration with high-pulse-energy IR lasers, the transverse dimensions of these structures scale down with wavelength. The size and materials enable designs using standard microfabrication processes, especially lithographic miniaturization, to further drive down costs of systems employing such structures.

This has potential benefit for accelerators used in medicine and cargo interrogation, among other areas. University-scale, or even laboratory-scale, GeV DLAs could enable widespread availability of x-ray free electron lasers (XFEL). XFELs have applications in basic science and small, low-cost systems could prove useful in medical imaging and therapy.

We design and fabricate DLA structures using standard silicon MEMS and thin-film processing techniques to enable increased performance and reduce complexity.

The image above shows simulated electric field strength along the center of the electron channel over one optical period of the driving laser and one grating period (seen at left). The black line (A) is the path of maximum acceleration a relativistic electron can take, while the grey line (D) is the path of maximum deceleration.