IPAC2017 - List of Authors (Jamison, S.P.)

Paper	Title	Page
THPAB053	Laser Heater Deisgn for the CLARA FEL Test Facility	3833
	A.D. Brynes, S.P. Jamison, B.D. Muratori, N. Thompson, P.H. Williams STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom S.P. Jamison, B.D. Muratori, N. Thompson, P.H. Williams Cockcroft Institute, Warrington, Cheshire, United Kingdom
	We present considerations of microbunching studies in the CLARA (Compact Linear Accelerator for Research and Applications), the proposed UK FEL test facility under construction at Daresbury Laboratory. CLARA, a high-brightness electron linac, presents an opportunity to study the microbunching instability. A number of theoretical models have been proposed concerning the causes of this instability, and it has also been observed at various FEL facilities. We have applied these models to the CLARA FEL, and propose a suitable laser heater design which will provide flexibility in terms of the range of modes of operation for CLARA. We also propose a method for inducing and controlling the microbunching instability via pulse stacking of the photoinjector laser.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB053
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WEPVA019	Group Velocity Matching in Dielectric-Lined Waveguides and its Role in Electron-THz Interaction	3296
SUSPSIK031	use link to see paper's listing under its alternate paper code
	A.L. Healy, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom D.M. Graham The University of Manchester, The Photon Science Institute, Manchester, United Kingdom S.P. Jamison STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Terahertz(THz)-driven dielectric-lined waveguides have applications in electron manipulation, particularly acceleration, as the use of dielectric allows for phase velocities below the speed of light. However matching a single frequency to the correct velocity does not maximise electron-THz interaction; waveguide dispersion typically results in an unmatched group velocity and so the pulse envelope of a short THz pulse changes along the length of the structure. This reduces field amplitude and therefore accelerating gradient as the envelope propagates at a different velocity to the electron. Presented here is an analysis of the effect of waveguide dispersion on THz-electron interaction and its influence on structure dimensions and choice of THz pulse generation. This effect on net acceleration is demonstrated via an example of a structure excited by a single-cycle THz pulse, with a comparison of multi-cycle, lower intensity THz pulses on net acceleration.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Laser Heater Deisgn for the CLARA FEL Test Facility

3833

A.D. Brynes, S.P. Jamison, B.D. Muratori, N. Thompson, P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.P. Jamison, B.D. Muratori, N. Thompson, P.H. Williams
Cockcroft Institute, Warrington, Cheshire, United Kingdom

We present considerations of microbunching studies in the CLARA (Compact Linear Accelerator for Research and Applications), the proposed UK FEL test facility under construction at Daresbury Laboratory. CLARA, a high-brightness electron linac, presents an opportunity to study the microbunching instability. A number of theoretical models have been proposed concerning the causes of this instability, and it has also been observed at various FEL facilities. We have applied these models to the CLARA FEL, and propose a suitable laser heater design which will provide flexibility in terms of the range of modes of operation for CLARA. We also propose a method for inducing and controlling the microbunching instability via pulse stacking of the photoinjector laser.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB053

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPVA019

Group Velocity Matching in Dielectric-Lined Waveguides and its Role in Electron-THz Interaction

3296

SUSPSIK031

use link to see paper's listing under its alternate paper code

A.L. Healy, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
D.M. Graham
The University of Manchester, The Photon Science Institute, Manchester, United Kingdom
S.P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Terahertz(THz)-driven dielectric-lined waveguides have applications in electron manipulation, particularly acceleration, as the use of dielectric allows for phase velocities below the speed of light. However matching a single frequency to the correct velocity does not maximise electron-THz interaction; waveguide dispersion typically results in an unmatched group velocity and so the pulse envelope of a short THz pulse changes along the length of the structure. This reduces field amplitude and therefore accelerating gradient as the envelope propagates at a different velocity to the electron. Presented here is an analysis of the effect of waveguide dispersion on THz-electron interaction and its influence on structure dimensions and choice of THz pulse generation. This effect on net acceleration is demonstrated via an example of a structure excited by a single-cycle THz pulse, with a comparison of multi-cycle, lower intensity THz pulses on net acceleration.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)