LINAC2014 - List of Keywords (extraction)

Paper	Title	Other Keywords	Page
MOPP035	Bead-Pull Measurement Method and Tuning of a Prototype CLIC Crab Cavity	cavity, electromagnetic-fields, coupling, simulation	134
	R. Wegner, W. Wuensch CERN, Geneva, Switzerland G. Burt, B.J. Woolley Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	A bead-pull method has been developed which measures in a single bead passage the amplitude and phase advance of deflecting mode travelling wave structures. This bead-pull method has been applied to measure and tune a Lancaster University-designed prototype crab cavity for CLIC. The technique and tuning results are described.

TUPP006	Design of Relativistic Magnetron for High Power Microwave Generation	electron, simulation, cathode, cavity	452
	R. Chandra, S.R. Ghodke, A.S. Patel, A. Sharma, S.K. Singh BARC, Mumbai, India
	A Linear Induction Accelerator based upon magnetic storage, utilising magnetic switches has been made and it is capable of providing a 400 kV diode voltage, 4 kA beam current for 100 ns pulse duration with 100 Hz repetition rate. It operates in a very high repetition rate due to the use of magnetic switches in it. The lesser shot to shot variation make this system ideal for a Relativistic Magnetron operation, where a huge dependence of output power on applied voltage and applied current is observed. A relativistic magnetron with axial extraction is analytically designed and simulated for this system. This relativistic magnetron is expected to give a power of 100 MW per pulse when operated in its full rating. The design features of this relativistic magnetron are presented here. This magnetron was designed for an output microwave frequency of 2.52 GHz. *J. Benford, ''Space Applications of High-Power Microwaves'', IEEE Trans. Plasma Sci., vol. 36, no. 3, pp. 569–581, Jun. 2008

TUPP018	Analysis of Systematic and Random Error in SRF Material Parameter Calculations	simulation, cavity, SRF, niobium	465
	S.J. Meyers, M. Liepe, S. Posen Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA M. Liepe Cornell University, Ithaca, New York, USA
	Funding: NSF Career award PHY-0841213 and DOE award ER41628 To understand the relationship between an RF cavity’s performance and the material on its surface, one must look at various parameters, including energy gap, mean free path, and residual resistance. Though SRIMP fits for seven parameters, three parameters are eliminated using measurement and literature values, and the uncertainty of the fit of the remaining four parameters is further reduced by synthesizing two 3-parameter fits, each from a different data set. To study random error, Monte Carlo simulations were performed of ideal data with added noise; for systematic error, contour plots of normalized residual sum of squares (RSS) of the polymorphic fit on inputted data were generated.
	Poster TUPP018 [1.183 MB]

TUPP077	High Precision Manufacturing for LINAC's	linac, vacuum, controls, laser	603
	F.M. Mirapeix, J. Añel HTS, Mendaro, Spain J. Amores, J. Presa, A. Urzainki DMP, Mendaro, Spain
	A big effort in R&D focused to the LINAC devices together with the know-how already deployed through emblematic projects places DMP in the state of the art of the extreme precision mechanics. This mechanic culture makes of DMP a natural partner in early stages of design or driver of a comprehensive solution, optimizing industrial risks, quality and due date. Surface roughness below 1 nanometer, figure errors better than 50 nanometers in OFE copper enhances lifetime and performance of many devices for LINAC's. Research in joining techniques and combining several alternative technologies to traditional machining improves figure stability and makes complex cooling systems possible.

THPP085	The Prototype of the Proton Injector for the European Spallation Source	plasma, proton, emittance, simulation	1044
	L. Celona, L. Andò, G. Castro, S. Gammino, D. Mascali, L. Neri, G. Torrisi INFN/LNS, Catania, Italy
	The update of the design of the PS-ESS source and of its LEBT has been carried out in 2013 and the construction is now ongoing. The Ion Source will be able to provide a proton beam current larger than 70 mA to the 3.6 MeV RFQ. Several innovative solutions have been implemented in the redesign phase in order to cope with high-reliability/high-performance requirements of the ESS project. A flexible magnetic system will allow to investigate alternative configurations for future ion current upgrade of the machine based on the formation of a denser plasma. Innovative set-ups have been also explored for beam extraction, transport and chopping. Calculations have shown that space charge compensation up to 95 % is needed to preserve the low emittance in the low energy beam transfer line (LEBT). In order to obtain the optimal proton beam pulse rise and fall time – that should be 100 ns – we propose a LEBT chopping configuration that permits hundred nanosecond rise times despite the LEBT compensation needs few microseconds. The ongoing development of a 3D PIC code will be also described, that should allow predicting and tuning the beam pulse for different source/LEBT operative configurations.

THPP133	LLRF System for the CEBAF Separator Upgrade	cavity, controls, LLRF, electron	1171
	T. E. Plawski, R. Bachimanchi, C. Hovater, D.J. Seidman, M.J. Wissmann JLab, Newport News, Virginia, USA
	The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of four new 750 MHz deflecting, normal conducting cavities in the 5th pass extraction region. This system will work together with existing 499 MHz RF Separator in order to allow simultaneous delivery of the beam to four CEBAF experimental halls. The RF system employs two digital LLRF systems controlling four cavities in a vector sum. Cavity tune information of the individual cavities is also obtained using a multiplexing scheme of the forward and reflected RF signals. In this paper we will present detailed LLRF design and current status of the CEBAF 750 MHz beam extraction system.

Paper

Title

Other Keywords

Page

MOPP035

Bead-Pull Measurement Method and Tuning of a Prototype CLIC Crab Cavity

cavity, electromagnetic-fields, coupling, simulation

134

R. Wegner, W. Wuensch
CERN, Geneva, Switzerland
G. Burt, B.J. Woolley
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

A bead-pull method has been developed which measures in a single bead passage the amplitude and phase advance of deflecting mode travelling wave structures. This bead-pull method has been applied to measure and tune a Lancaster University-designed prototype crab cavity for CLIC. The technique and tuning results are described.

TUPP006

Design of Relativistic Magnetron for High Power Microwave Generation

electron, simulation, cathode, cavity

452

R. Chandra, S.R. Ghodke, A.S. Patel, A. Sharma, S.K. Singh
BARC, Mumbai, India

A Linear Induction Accelerator based upon magnetic storage, utilising magnetic switches has been made and it is capable of providing a 400 kV diode voltage, 4 kA beam current for 100 ns pulse duration with 100 Hz repetition rate. It operates in a very high repetition rate due to the use of magnetic switches in it. The lesser shot to shot variation make this system ideal for a Relativistic Magnetron operation, where a huge dependence of output power on applied voltage and applied current is observed. A relativistic magnetron with axial extraction is analytically designed and simulated for this system. This relativistic magnetron is expected to give a power of 100 MW per pulse when operated in its full rating. The design features of this relativistic magnetron are presented here. This magnetron was designed for an output microwave frequency of 2.52 GHz.
*J. Benford, ''Space Applications of High-Power Microwaves'', IEEE Trans. Plasma Sci., vol. 36, no. 3, pp. 569–581, Jun. 2008

TUPP018

Analysis of Systematic and Random Error in SRF Material Parameter Calculations

simulation, cavity, SRF, niobium

465

S.J. Meyers, M. Liepe, S. Posen
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
M. Liepe
Cornell University, Ithaca, New York, USA

Funding: NSF Career award PHY-0841213 and DOE award ER41628
To understand the relationship between an RF cavity’s performance and the material on its surface, one must look at various parameters, including energy gap, mean free path, and residual resistance. Though SRIMP fits for seven parameters, three parameters are eliminated using measurement and literature values, and the uncertainty of the fit of the remaining four parameters is further reduced by synthesizing two 3-parameter fits, each from a different data set. To study random error, Monte Carlo simulations were performed of ideal data with added noise; for systematic error, contour plots of normalized residual sum of squares (RSS) of the polymorphic fit on inputted data were generated.

Poster TUPP018 [1.183 MB]

TUPP077

High Precision Manufacturing for LINAC's

linac, vacuum, controls, laser

603

F.M. Mirapeix, J. Añel
HTS, Mendaro, Spain
J. Amores, J. Presa, A. Urzainki
DMP, Mendaro, Spain

A big effort in R&D focused to the LINAC devices together with the know-how already deployed through emblematic projects places DMP in the state of the art of the extreme precision mechanics. This mechanic culture makes of DMP a natural partner in early stages of design or driver of a comprehensive solution, optimizing industrial risks, quality and due date. Surface roughness below 1 nanometer, figure errors better than 50 nanometers in OFE copper enhances lifetime and performance of many devices for LINAC's. Research in joining techniques and combining several alternative technologies to traditional machining improves figure stability and makes complex cooling systems possible.

THPP085

The Prototype of the Proton Injector for the European Spallation Source

plasma, proton, emittance, simulation

1044

L. Celona, L. Andò, G. Castro, S. Gammino, D. Mascali, L. Neri, G. Torrisi
INFN/LNS, Catania, Italy

The update of the design of the PS-ESS source and of its LEBT has been carried out in 2013 and the construction is now ongoing. The Ion Source will be able to provide a proton beam current larger than 70 mA to the 3.6 MeV RFQ. Several innovative solutions have been implemented in the redesign phase in order to cope with high-reliability/high-performance requirements of the ESS project. A flexible magnetic system will allow to investigate alternative configurations for future ion current upgrade of the machine based on the formation of a denser plasma. Innovative set-ups have been also explored for beam extraction, transport and chopping. Calculations have shown that space charge compensation up to 95 % is needed to preserve the low emittance in the low energy beam transfer line (LEBT). In order to obtain the optimal proton beam pulse rise and fall time – that should be 100 ns – we propose a LEBT chopping configuration that permits hundred nanosecond rise times despite the LEBT compensation needs few microseconds. The ongoing development of a 3D PIC code will be also described, that should allow predicting and tuning the beam pulse for different source/LEBT operative configurations.

THPP133

LLRF System for the CEBAF Separator Upgrade

cavity, controls, LLRF, electron

1171

T. E. Plawski, R. Bachimanchi, C. Hovater, D.J. Seidman, M.J. Wissmann
JLab, Newport News, Virginia, USA

The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of four new 750 MHz deflecting, normal conducting cavities in the 5th pass extraction region. This system will work together with existing 499 MHz RF Separator in order to allow simultaneous delivery of the beam to four CEBAF experimental halls. The RF system employs two digital LLRF systems controlling four cavities in a vector sum. Cavity tune information of the individual cavities is also obtained using a multiplexing scheme of the forward and reflected RF signals. In this paper we will present detailed LLRF design and current status of the CEBAF 750 MHz beam extraction system.