Paper  Title  Other Keywords  Page 

MOPLG01  Challenges in Simulating Beam Dynamics of Dielectric Laser Acceleration  laser, electron, experiment, acceleration  120 


Funding: ACHIP is funded by the Gordon and Betty Moore Foundation (Grant No. GBMF4744). U.N. acknowledges German BMBF Grant No. FKZ:05K16RDB. B.C. acknowledges NERSC, Contract No. DEAC0205CH11231. Dielectric Laser Acceleration (DLA) achieves the high est gradients among structurebased 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) laserbased 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 multicell 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. 

Slides MOPLG01 [3.947 MB]  
DOI •  reference for this paper ※ https://doi.org/10.18429/JACoWICAP2018MOPLG01  
About •  paper received ※ 20 October 2018 paper accepted ※ 24 October 2018 issue date ※ 26 January 2019  
Export •  reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPAF13  Calculation of the AGS Optics Based on 3D Fields Derived From Experimentally Measured Fields on Median Plane  extraction, closedorbit, kicker, optics  209 


Funding: Work supported by the US Department of Energy Closed orbit calculations of the AGS synchrotron were performed and the beam parameters at the extraction point of the AGS [1] were calculated using the RAYTRACE computer code [2] which was modified to generate 3D fields from the experimentally measured field maps on the median plane of the AGS combined function magnets. The algorithm which generates 3D fields from field maps on a plane is described in reference [3] which discusses the details of the mathematical foundation of this approach. In this presentation we will discuss results from studies [1,4] that are based on the 3D fields generated from the known field components on a rectangular grid of a plane. A brief overview of the algorithm used will be given, and two methods of calculating the required field derivatives on the plane will be presented. The calculated 3D fields of a modified Halbach magnet [5] of inner radius of 4.4 cm will be calculated using the two different methods of calculating the field derivatives on the plane and the calculated fields will be compared against the ’ideal’ fields as calculated by the OPERA computer code [6]. [1] N. Tsoupas et. al. ’Closed orbit calculations at AGS and Extraction Beam Parameters at H13 AD/RHIC/RD75 Oct. 1994 [2] S.B. Kowalski and H.A. Enge ’The IonOptical Program Raytrace’ NIM A258 (1987) 407 [3] K. Makino, M. Berz, C. Johnstone, Int. Journal of Modern Physics A 26 (2011) 18071821 [4] N. Tsoupas et. al. ’Effects of Dipole Magnet Inhomogeneity on the Beam Ellipsoid’ NIM A258 (1987) 421425 [5] ’The CBETA project: arXiv.org > physics > arXiv:1706.04245’’ [6] Vector Fields Inc. https://operafea.com/ 

Slides TUPAF13 [1.772 MB]  
DOI •  reference for this paper ※ https://doi.org/10.18429/JACoWICAP2018TUPAF13  
About •  paper received ※ 20 October 2018 paper accepted ※ 07 December 2018 issue date ※ 26 January 2019  
Export •  reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  