FEL2014 - List of Keywords (linear-collider)

Paper	Title	Other Keywords	Page
MOP062	FEL Proposal Based on CLIC X-Band Structure	linac, FEL, klystron, undulator	186
	A.A. Aksoy, O. Yavaş Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey E. Adli University of Oslo, Oslo, Norway D. Angal-Kalinin, J.A. Clarke STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc SLSA, Clayton, Australia N. Charitonidis, A. Grudiev, A. Latina, D. Schulte, I. Syratchev, W. Wuensch CERN, Geneva, Switzerland G. D'Auria, S. Di Mitri Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy W. Fang, Q. Gu SINAP, Shanghai, People's Republic of China E.N. Gazis National Technical University of Athens, Athens, Greece M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden Z. Nergiz Nigde University, Nigde, Turkey
	A linear accelerating structure with an average loaded gradient of 100 MV/m at X-Band frequencies has been demonstrated in the CLIC study. Recently, it has been proposed to use this structure to drive an FEL linac. In contrast to CLIC the linac would be powered by klystrons not by an RF source created by a drive beam. The main advantage of this proposal is achieving the required energies in a very short distance, thus the facility would be rather compact. In this study, we present the structure choice and conceptual design parameters of a facility which could generate laser photon pulses below Angstrom. Shorter wavelengths can also be reached with slightly increasing the energy.

THP051	Thyratron Replacement	operation, klystron, network, target	847
	I. Roth, M.P.J. Gaudreau, M.K. Kempkes Diversified Technologies, Inc., Bedford, Massachusetts, USA
	Funding: DOE Contract DE-SC0011292 Semiconductor thyristers have long been used as a replacement for thyratrons, at least in low power or long pulse RF systems. To date, however, such thyristor assemblies have not demonstrated the reliability needed for installation in short pulse, high peak power RF stations used with many pulsed electron accelerators. The difficulty is that a fast rising current in a thyristor tends to be carried in a small region, rather than across the whole device, and this localized current concentration can cause a short circuit failure. It is not clear that this failure mode can be overcome with currently available device designs. An alternate solid-state device, the insulated-gate bipolar transistor (IGBT), can readily operate at the speed needed for the accelerator, but commercial IGBTs cannot handle the voltage and current required. Diversified Technologies, Inc. (DTI) has patented and refined the technology required to build these arrays of series-parallel connected switches. Under DOE contract, DTI is currently developing an affordable, reliable, form-fit-function replacement for the klystron modulator thyratrons at SLAC capable of pulsing at 360 kV, 420 A, 6 μs, and 120 Hz.

THP052	Affordable Short Pulse Marx Modulator	high-voltage, controls, network, collider	849
	R.A. Phillips, G. DelPriore, M.P.J. Gaudreau, M.K. Kempkes Diversified Technologies, Inc., Bedford, Massachusetts, USA J.A. Casey Rockfield Research Inc., Las Vegas, Nevada, USA
	Funding: DOE Contract DE-SC0004251 High voltage short-pulse klystron modulators are required for numerous X-Band accelerator designs. At the very high voltages required for these transmitters, all of the existing designs are based on pulse transformers, which significantly limits their performance and efficiency. There is not a fully optimized, transformer-less modulator design capable of meeting the demanding requirements of very peak power, short pulse RF stations. Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator. The modulator is designed for high efficiency in the 100 kV to 500 kV range, for currents up to 250 A, pulse lengths of 0.2 to 5.0 μs, and risetimes <300 ns. Key objectives of the development effort are modularity and scalability, combined with low cost and ease of manufacture. For short-pulse modulators, this Marx topology provides a means to achieve fast risetimes and flattop control that are not available with hard switch or transformer-coupled topologies. The system is in the final stages of testing prior to installation at Yale University.

THC03	Suppression of the CSR-induced Emittance Growth in Achromats using Two-dimensional point-kick Analysis	dipole, emittance, simulation, optics	976
	Y. Jiao, X. Cui, X.Y. Huang, G. Xu IHEP, Beijing, People's Republic of China
	Coherent synchrotron radiation (CSR) effect causes transverse emittance dilution in high-brightness light sources and linear colliders. Suppression of the emittance growth induced by CSR is essential and critical to preserve the beam quality and to help improve the machine performance. To evaluate the CSR effect analytically, we propose a novel method, named “two-dimensional point-kick analysis”. In this method, the CSR-induced emittance growth in an n-dipole achromat can be evaluated with the analysis of only the motion of particle in (x, x') two-dimensional plane with n-point kicks, which can be, to a large extent, counted separately. To demonstrate the effectiveness of this method, the CSR effect in a two-diople achromat and a symmetric TBA is studied, and generic conditions of suppressing the CSR-induced emittance growth, which are independent of concrete element parameters and are robust against the variation of initial beam distribution, are found. These conditions are verified with the ELEGANT simulations and can be rather easily applied to real machines.
	Slides THC03 [1.941 MB]

Paper

Title

Other Keywords

Page

MOP062

FEL Proposal Based on CLIC X-Band Structure

linac, FEL, klystron, undulator

186

A.A. Aksoy, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
E. Adli
University of Oslo, Oslo, Norway
D. Angal-Kalinin, J.A. Clarke
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc
SLSA, Clayton, Australia
N. Charitonidis, A. Grudiev, A. Latina, D. Schulte, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
G. D'Auria, S. Di Mitri
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
W. Fang, Q. Gu
SINAP, Shanghai, People's Republic of China
E.N. Gazis
National Technical University of Athens, Athens, Greece
M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
Z. Nergiz
Nigde University, Nigde, Turkey

A linear accelerating structure with an average loaded gradient of 100 MV/m at X-Band frequencies has been demonstrated in the CLIC study. Recently, it has been proposed to use this structure to drive an FEL linac. In contrast to CLIC the linac would be powered by klystrons not by an RF source created by a drive beam. The main advantage of this proposal is achieving the required energies in a very short distance, thus the facility would be rather compact. In this study, we present the structure choice and conceptual design parameters of a facility which could generate laser photon pulses below Angstrom. Shorter wavelengths can also be reached with slightly increasing the energy.

THP051

Thyratron Replacement

operation, klystron, network, target

847

I. Roth, M.P.J. Gaudreau, M.K. Kempkes
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: DOE Contract DE-SC0011292
Semiconductor thyristers have long been used as a replacement for thyratrons, at least in low power or long pulse RF systems. To date, however, such thyristor assemblies have not demonstrated the reliability needed for installation in short pulse, high peak power RF stations used with many pulsed electron accelerators. The difficulty is that a fast rising current in a thyristor tends to be carried in a small region, rather than across the whole device, and this localized current concentration can cause a short circuit failure. It is not clear that this failure mode can be overcome with currently available device designs. An alternate solid-state device, the insulated-gate bipolar transistor (IGBT), can readily operate at the speed needed for the accelerator, but commercial IGBTs cannot handle the voltage and current required. Diversified Technologies, Inc. (DTI) has patented and refined the technology required to build these arrays of series-parallel connected switches. Under DOE contract, DTI is currently developing an affordable, reliable, form-fit-function replacement for the klystron modulator thyratrons at SLAC capable of pulsing at 360 kV, 420 A, 6 μs, and 120 Hz.

THP052

Affordable Short Pulse Marx Modulator

high-voltage, controls, network, collider

849

R.A. Phillips, G. DelPriore, M.P.J. Gaudreau, M.K. Kempkes
Diversified Technologies, Inc., Bedford, Massachusetts, USA
J.A. Casey
Rockfield Research Inc., Las Vegas, Nevada, USA

Funding: DOE Contract DE-SC0004251
High voltage short-pulse klystron modulators are required for numerous X-Band accelerator designs. At the very high voltages required for these transmitters, all of the existing designs are based on pulse transformers, which significantly limits their performance and efficiency. There is not a fully optimized, transformer-less modulator design capable of meeting the demanding requirements of very peak power, short pulse RF stations. Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator. The modulator is designed for high efficiency in the 100 kV to 500 kV range, for currents up to 250 A, pulse lengths of 0.2 to 5.0 μs, and risetimes <300 ns. Key objectives of the development effort are modularity and scalability, combined with low cost and ease of manufacture. For short-pulse modulators, this Marx topology provides a means to achieve fast risetimes and flattop control that are not available with hard switch or transformer-coupled topologies. The system is in the final stages of testing prior to installation at Yale University.

THC03

Suppression of the CSR-induced Emittance Growth in Achromats using Two-dimensional point-kick Analysis

dipole, emittance, simulation, optics

976

Y. Jiao, X. Cui, X.Y. Huang, G. Xu
IHEP, Beijing, People's Republic of China

Coherent synchrotron radiation (CSR) effect causes transverse emittance dilution in high-brightness light sources and linear colliders. Suppression of the emittance growth induced by CSR is essential and critical to preserve the beam quality and to help improve the machine performance. To evaluate the CSR effect analytically, we propose a novel method, named “two-dimensional point-kick analysis”. In this method, the CSR-induced emittance growth in an n-dipole achromat can be evaluated with the analysis of only the motion of particle in (x, x') two-dimensional plane with n-point kicks, which can be, to a large extent, counted separately. To demonstrate the effectiveness of this method, the CSR effect in a two-diople achromat and a symmetric TBA is studied, and generic conditions of suppressing the CSR-induced emittance growth, which are independent of concrete element parameters and are robust against the variation of initial beam distribution, are found. These conditions are verified with the ELEGANT simulations and can be rather easily applied to real machines.

Slides THC03 [1.941 MB]