TEMF, TU Darmstadt, Darmstadt, Germany
PSI, Villigen PSI, Switzerland
DESY, Hamburg, Germany
Stanford University, Stanford, California, USA
CFEL, Hamburg, Germany
UCLA, Los Angeles, California, USA
Tech-X, Boulder, Colorado, USA
SLAC, Menlo Park, California, USA
EPFL, Lausanne, Switzerland
Universität Bern, Institute of Applied Physics, Bern, Switzerland
University of Erlangen-Nuremberg, Erlangen, Germany
NTHU, Hsinchu, Taiwan
Friedrich-Alexander Universität Erlangen-Nuernberg, University Erlangen-Nuernberg LFTE, Erlangen, Germany
Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
Purdue University, West Lafayette, Indiana, USA
LANL, Los Alamos, New Mexico, USA
Dielectric Laser Acceleration (DLA) achieves the high- est gradients among structure-based electron accelerators. The use of dielectrics increases the breakdown field limit, and thus the achievable gradient, by a factor of at least 10 in comparison to metals. Experimental demonstrations of DLA in 2013 led to the Accelerator on a Chip International Program (ACHIP), funded by the Gordon and Betty Moore Foundation. In ACHIP, our main goal is to build an acceler- ator on a silicon chip, which can accelerate electrons from below 100keV to above 1MeV with a gradient of at least 100MeV/m. For stable acceleration on the chip, magnet- only focusing techniques are insufficient to compensate the strong acceleration defocusing. Thus spatial harmonic and Alternating Phase Focusing (APF) laser-based focusing tech- niques have been developed. We have also developed the simplified symplectic tracking code DLAtrack6D, which makes use of the periodicity and applies only one kick per DLA cell, which is calculated by the Fourier coefficient of the synchronous spatial harmonic. Due to coupling, the Fourier coefficients of neighboring cells are not entirely independent and a field flatness optimization (similarly as in multi-cell cavities) needs to be performed. The simu- lation of the entire accelerator on a chip by a Particle In Cell (PIC) code is possible, but impractical for optimization purposes. Finally, we have also outlined the treatment of wake field effects in attosecond bunches in the grating within DLAtrack6D, where the wake function is computed by an external solver.
