LINAC2016 - List of Authors (Burt, G.)

Paper	Title	Page
MOOP09	Dielectric and THz Acceleration (Data) Programme at the Cockcroft Institute	62
MOPRC003	use link to see paper's listing under its alternate paper code
	S.P. Jamison, Y.M. Saveliev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R.B. Appleby, H.L. Owen, T.H. Pacey, T.H. Pacey, G.X. Xia UMAN, Manchester, United Kingdom G. Burt, R. Letizia, C. Paoloni Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A.W. Cross USTRAT/SUPA, Glasgow, United Kingdom D.M. Graham The University of Manchester, The Photon Science Institute, Manchester, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: This work has been funded by STFC Normal conducting RF systems are currently able to pro-vide gradients of around 100 MV/m, limited by break-down on the metallic structures. The breakdown rate is known to scale with pulse length and, in conventional RF systems, this is limited by the filling time of the RF struc-ture. Progressing to higher frequencies, from RF to THz and optical, can utilise higher gradient structures due to the fast filling times. Further increases in gradient may be possible by replacing metallic structures with dielectric structures. The DATA programme at the Cockcroft Insti-tute is investigating concepts for particle acceleration with laser driven THz sources and dielectric structures, beam driven dielectric and metallic structures, and optical and infrared laser acceleration using grating and photonic structures. A cornerstone of the programme is the VELA and CLARA electron accelerator test facility at Daresbury Laboratory which will be used for proof-of-principle experiments demonstrating particle acceleration.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOOP09
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MOPLR011	Design of a Dielectric-lined Waveguide for Terahertz-driven Linear Electron Acceleration	158
SPWR012	use link to see paper's listing under its alternate paper code
	A.L. Healy, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom M.J. Cliffe, 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 R. Valizadeh Cockcroft Institute, Warrington, Cheshire, United Kingdom
	A dielectric-lined waveguide has been designed for use as an accelerating structure in terahertz-driven electron acceleration experiments at Daresbury. Experimental verification of acceleration will take place on Versatile Electron Linear Accelerator (VELA). The choice of a rectangular waveguide structure with sidewall dielectric layers enables tuning by varying the spacing between dielectric slabs to account for potential manufacturing errors. Schemes for coupling free-space single cycle THz pulses into the waveguide have been evaluated and optimised through CST simulation. Comparison of simulation with experimental measurements will also be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR011
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MOPLR016	Status of the Injection System of the CLARA FEL Test Facility	174
	B.L. Militsyn, D. Angal-Kalinin, R.K. Buckley, R.J. Cash, J.A. Clarke, L.S. Cowie, B.D. Fell, P. Goudket, T.J. Jones, K.B. Marinov, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, T.C.Q. Noakes, B.J.A. Shepherd, R. Valizadeh, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom V.V. Paramonov RAS/INR, Moscow, Russia
	The 250 MeV CLARA FEL test facility is now under construction at Daresbury Laboratory. Electron beam for this facility is provided by two normal conducting S-band photocathode guns: a 10 Hz 2.5 cell gun earlier used as the injector for the VELA machine, and a 400 Hz 1.5 cell gun now under commissioning. At the initial stage of Phase I CLARA will operate with the 10 Hz gun and a 45 MeV 2 m long linac section working as a buncher and/or booster. The beam will be deflected into the existing VELA beamline with an S-bend and directed to the spectrometer line for analysing beam properties or into one of two VELA user areas. The 400 Hz gun will be installed in the VELA beamline for detailed high power RF and beam commissioning in the VELA beam diagnostics suite. As the 400 Hz gun is equipped with an interchangeable photocathode it is possible to investigate different metal photocathodes and select the one providing minimal beam emittance at highest quantum efficiency. A state of the art photocathode preparation system is under commissioning at Daresbury. After commissioning the 400 Hz gun will be installed to the CLARA beam line to deliver high energy, high repetition rate beams for the FEL facility, and the 10 Hz gun will be returned to the VELA beam line.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR016
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MOPLR066	ProBE: Proton Boosting Extension for Imaging and Therapy	283
	S. Pitman, R. Apsimon, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A.F. Green, H.L. Owen UMAN, Manchester, United Kingdom A. Grudiev, A. Solodko, W. Wuensch CERN, Geneva, Switzerland
	Funding: This work was funded by STFC and IPS Proton beam therapy has been shown to be a promising alternative to traditional radiotherapy, especially for paedi- atric malignancies and radio-resistant tumours. Allowing a highly precise tumour irradiation, it is currently limited by range verification. Several imaging modalities can be utilised for treatment planning, but typically X-ray CT is used. CT scans require conversion from Hounsfield units to estimate the proton stopping power (PSP) of the tissue be- ing treated, and this produces inaccuracy. Proton CT (pCT) measures PSP and is thought to allow an improvement of the treatment accuracy. The Christie Hospital will use a 250 MeV cyclotron for proton therapy, in this paper a pulsed linac upgrade is proposed, to provide 350 MeV protons for pCT within the facility. Space contraints require a compact, high gradient (HG) solution that is reliable and affordable.
	Poster MOPLR066 [0.610 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR066
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TUPRC016	S-Band Booster Design and Emittance Preservation for the Awake e-Injector	449
	O. Mete Apsimon, R. Apsimon, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S. Döbert CERN, Geneva, Switzerland G.X. Xia UMAN, Manchester, United Kingdom
	AWAKE is a proton driven plasma wakefield acceleration experiment at CERN which uses the protons from the SPS. It aims to study the self modulation instability of a proton bunch and the acceleration of an externally injected electron beam in the plasma wakefields, during the so called Phase II until the technical stop of LHC and its injector chain (LS2) in 2019. The external electron beam of 0.1 to 1nC charge per bunch will be generated using an S-band photo injector with a high QE semiconducting cathode. A booster linac was designed to allow variable electron energy for the plasma experiments from 16 to 20 MeV. For an RF gun and booster system, emittance control can be highlighted as a challenging transmission task. Once the beam emittance is compensated at the gun exit and the beam is delivered to the booster with an optimum beam envelope, fringing fields and imperfections in the linac become critical for preserving the injection emittance. This paper summarises the rf design studies in order to preserve the initial beam emittance at the entrance of the linac and alternative mitigation schemes in case of emittance growth.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPRC016
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TUPRC017	Field Flatness and Frequency Tuning of the CLARA High Repetition Rate Photoinjector	452
	L.S. Cowie, P. Goudket, B.L. Militsyn STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom T.J. Jones STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom B. Keune RI Research Instruments GmbH, Bergisch Gladbach, Germany
	The High Repetition Rate Photoinjector, designed for the CLARA FEL at Daresbury Laboratory, was tuned at the manufacturers for both field flatness and frequency. Due to the high average power in the cavity of 6.8 kW the cavity requires significant cooling, achieved by water channels in the cavity body. These channels prohibit the use of tuning studs to tune the cavity. The cavity was tuned by taking pre-braze clamped low power RF measurements and using the data to trim the cavity cells to the optimum length for both field flatness and frequency. The optimum field flatness is 100% and the design frequency is 2998.5 MHz. Both cells were trimmed in 3 stages, resulting in a post-braze frequency of 2998.51 MHz and field flatness of 98%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPRC017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOOP09

Dielectric and THz Acceleration (Data) Programme at the Cockcroft Institute

62

MOPRC003

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

S.P. Jamison, Y.M. Saveliev
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R.B. Appleby, H.L. Owen, T.H. Pacey, T.H. Pacey, G.X. Xia
UMAN, Manchester, United Kingdom
G. Burt, R. Letizia, C. Paoloni
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A.W. Cross
USTRAT/SUPA, Glasgow, United Kingdom
D.M. Graham
The University of Manchester, The Photon Science Institute, Manchester, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: This work has been funded by STFC
Normal conducting RF systems are currently able to pro-vide gradients of around 100 MV/m, limited by break-down on the metallic structures. The breakdown rate is known to scale with pulse length and, in conventional RF systems, this is limited by the filling time of the RF struc-ture. Progressing to higher frequencies, from RF to THz and optical, can utilise higher gradient structures due to the fast filling times. Further increases in gradient may be possible by replacing metallic structures with dielectric structures. The DATA programme at the Cockcroft Insti-tute is investigating concepts for particle acceleration with laser driven THz sources and dielectric structures, beam driven dielectric and metallic structures, and optical and infrared laser acceleration using grating and photonic structures. A cornerstone of the programme is the VELA and CLARA electron accelerator test facility at Daresbury Laboratory which will be used for proof-of-principle experiments demonstrating particle acceleration.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOOP09

Export •

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

MOPLR011

Design of a Dielectric-lined Waveguide for Terahertz-driven Linear Electron Acceleration

158

SPWR012

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

A.L. Healy, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
M.J. Cliffe, 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
R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom

A dielectric-lined waveguide has been designed for use as an accelerating structure in terahertz-driven electron acceleration experiments at Daresbury. Experimental verification of acceleration will take place on Versatile Electron Linear Accelerator (VELA). The choice of a rectangular waveguide structure with sidewall dielectric layers enables tuning by varying the spacing between dielectric slabs to account for potential manufacturing errors. Schemes for coupling free-space single cycle THz pulses into the waveguide have been evaluated and optimised through CST simulation. Comparison of simulation with experimental measurements will also be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR011

Export •

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

MOPLR016

Status of the Injection System of the CLARA FEL Test Facility

174

B.L. Militsyn, D. Angal-Kalinin, R.K. Buckley, R.J. Cash, J.A. Clarke, L.S. Cowie, B.D. Fell, P. Goudket, T.J. Jones, K.B. Marinov, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, T.C.Q. Noakes, B.J.A. Shepherd, R. Valizadeh, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
V.V. Paramonov
RAS/INR, Moscow, Russia

The 250 MeV CLARA FEL test facility is now under construction at Daresbury Laboratory. Electron beam for this facility is provided by two normal conducting S-band photocathode guns: a 10 Hz 2.5 cell gun earlier used as the injector for the VELA machine, and a 400 Hz 1.5 cell gun now under commissioning. At the initial stage of Phase I CLARA will operate with the 10 Hz gun and a 45 MeV 2 m long linac section working as a buncher and/or booster. The beam will be deflected into the existing VELA beamline with an S-bend and directed to the spectrometer line for analysing beam properties or into one of two VELA user areas. The 400 Hz gun will be installed in the VELA beamline for detailed high power RF and beam commissioning in the VELA beam diagnostics suite. As the 400 Hz gun is equipped with an interchangeable photocathode it is possible to investigate different metal photocathodes and select the one providing minimal beam emittance at highest quantum efficiency. A state of the art photocathode preparation system is under commissioning at Daresbury. After commissioning the 400 Hz gun will be installed to the CLARA beam line to deliver high energy, high repetition rate beams for the FEL facility, and the 10 Hz gun will be returned to the VELA beam line.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR016

Export •

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

MOPLR066

ProBE: Proton Boosting Extension for Imaging and Therapy

283

S. Pitman, R. Apsimon, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A.F. Green, H.L. Owen
UMAN, Manchester, United Kingdom
A. Grudiev, A. Solodko, W. Wuensch
CERN, Geneva, Switzerland

Funding: This work was funded by STFC and IPS
Proton beam therapy has been shown to be a promising alternative to traditional radiotherapy, especially for paedi- atric malignancies and radio-resistant tumours. Allowing a highly precise tumour irradiation, it is currently limited by range verification. Several imaging modalities can be utilised for treatment planning, but typically X-ray CT is used. CT scans require conversion from Hounsfield units to estimate the proton stopping power (PSP) of the tissue be- ing treated, and this produces inaccuracy. Proton CT (pCT) measures PSP and is thought to allow an improvement of the treatment accuracy. The Christie Hospital will use a 250 MeV cyclotron for proton therapy, in this paper a pulsed linac upgrade is proposed, to provide 350 MeV protons for pCT within the facility. Space contraints require a compact, high gradient (HG) solution that is reliable and affordable.

Poster MOPLR066 [0.610 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR066

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

TUPRC016

S-Band Booster Design and Emittance Preservation for the Awake e-Injector

449

O. Mete Apsimon, R. Apsimon, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
S. Döbert
CERN, Geneva, Switzerland
G.X. Xia
UMAN, Manchester, United Kingdom

AWAKE is a proton driven plasma wakefield acceleration experiment at CERN which uses the protons from the SPS. It aims to study the self modulation instability of a proton bunch and the acceleration of an externally injected electron beam in the plasma wakefields, during the so called Phase II until the technical stop of LHC and its injector chain (LS2) in 2019. The external electron beam of 0.1 to 1nC charge per bunch will be generated using an S-band photo injector with a high QE semiconducting cathode. A booster linac was designed to allow variable electron energy for the plasma experiments from 16 to 20 MeV. For an RF gun and booster system, emittance control can be highlighted as a challenging transmission task. Once the beam emittance is compensated at the gun exit and the beam is delivered to the booster with an optimum beam envelope, fringing fields and imperfections in the linac become critical for preserving the injection emittance. This paper summarises the rf design studies in order to preserve the initial beam emittance at the entrance of the linac and alternative mitigation schemes in case of emittance growth.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPRC016

Export •

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

TUPRC017

Field Flatness and Frequency Tuning of the CLARA High Repetition Rate Photoinjector

452

L.S. Cowie, P. Goudket, B.L. Militsyn
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
B. Keune
RI Research Instruments GmbH, Bergisch Gladbach, Germany

The High Repetition Rate Photoinjector, designed for the CLARA FEL at Daresbury Laboratory, was tuned at the manufacturers for both field flatness and frequency. Due to the high average power in the cavity of 6.8 kW the cavity requires significant cooling, achieved by water channels in the cavity body. These channels prohibit the use of tuning studs to tune the cavity. The cavity was tuned by taking pre-braze clamped low power RF measurements and using the data to trim the cavity cells to the optimum length for both field flatness and frequency. The optimum field flatness is 100% and the design frequency is 2998.5 MHz. Both cells were trimmed in 3 stages, resulting in a post-braze frequency of 2998.51 MHz and field flatness of 98%.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPRC017

Export •

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