IPAC2019 - List of Authors (Spataro, B.)

Paper	Title	Page
MOPGW030	New Analytical Derivation of Group Velocity in TW Accelerating Structures	155
SUSPFO035	use link to see paper's listing under its alternate paper code
	M. Behtouei, M. Migliorati, L. Palumbo Sapienza University of Rome, Rome, Italy L. Faillace Universita’ degli Studi di Milano & INFN, Milano, Italy B. Spataro INFN/LNF, Frascati, Italy
	Ultra high-gradient accelerating structures are needed for the next generation of compact light sources. In the framework of the Compact Light XLS project, we are studying a high harmonic traveling-wave accelerating structure operating at a frequency of 35.982 GHz, in order to linearize the longitudinal space phase. In this paper, we propose a new analytical approach for the estimation of the group velocity in the structure and we compare it with numerical electromagnetic simulations that are carried out by using the code HFSS in the frequency domain.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW030
About •	paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUXXPLM3	First Operation of a Hybrid e-Gun at the Schlesinger Center for Compact Accelerators in Ariel University	1171
	A.N. Nause, A. Fukasawa, J.B. Rosenzweig, R.J. Roussel UCLA, Los Angeles, USA A. Friedman Ariel University, Ariel, Israel B. Spataro INFN/LNF, Frascati, Italy
	Funding: Israel Ministry of Defence Israel Ministry of Science A novel hybrid photo injector was designed and partially tested at the UCLA Particle Beam Physics Laboratory. It was later commissioned at Ariel University in Israel as an on-going collaboration between the two universities. This unique, new generation design provides a radically simpler approach to RF feeding of a gun/buncher system, leading to a much shorter beam via velocity bunching owed to an attached traveling wave section of the photo-injector. This design results in better performance in beam parameters, providing a high quality electron beam, with energy of 6 MeV, emittance of app 3 μm, and a 150 fs pulse duration at up to 1 nC per pulse. The Hybrid gun is driven by a SLAC XK5 Klystron as the high power RF source, and third harmonic of a fs level IR Laser amplifier (266 nm) to drive the Cathode. The unique e-gun will produce an electron pulse for a THz FEL, which will operate at the super-radiance regime, and therefore requires extraordinary beam properties. This paper briefly describes the gun and presents initial operational results from the gun and its sub-systems.
	Slides TUXXPLM3 [9.526 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUXXPLM3
About •	paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRB032	The CompactLight Design Study Project	1756
	G. D’Auria, S. Di Mitri, R.A. Rochow Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy M. Aicheler HIP, University of Helsinki, Finland A.A. Aksoy Ankara University, Accelerator Technologies Institute, Golbasi, Turkey D. Alesini, M. Bellaveglia, B. Buonomo, F. Cardelli, M. Croia, M. Diomede, M. Ferrario, A. Gallo, A. Giribono, L. Piersanti, B. Spataro, C. Vaccarezza INFN/LNF, Frascati, Italy R. Apsimon, A. Castilla Cockcroft Institute, Lancaster University, Lancaster, United Kingdom J.M. Arnesano, F. Bosco, L. Ficcadenti, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy A. Bernhard, J. Gethmann KIT, Karlsruhe, Germany G. Burt Lancaster University, Lancaster, United Kingdom M. Calvi, T. Schmidt, K. Zhang PSI, Villigen PSI, Switzerland H.M. Castaneda Cortes, J.A. Clarke, D.J. Dunning, N. Thompson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom A.W. Cross, L. Zhang USTRAT/SUPA, Glasgow, United Kingdom G. Dattoli, F. Nguyen, A. Petralia ENEA C.R. Frascati, Frascati (Roma), Italy R.T. Dowd, D. Zhu AS - ANSTO, Clayton, Australia W.D. Fang SINAP, Shanghai, People’s Republic of China A. Faus-Golfe, Y. Han LAL, Orsay, France E.N. Gazis, N. Gazis National Technical University of Athens, Zografou, Greece R. Geometrante, M. Kokole KYMA, Trieste, Italy V.A. Goryashko, M. Jacewicz, R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden X.J.A. Janssen, J.M.A. Priem VDL ETG, Eindhoven, The Netherlands A. Latina, X. Liu, C. Rossi, D. Schulte, S. Stapnes, X.W. Wu, W. Wuensch CERN, Geneva, Switzerland O.J. Luiten, P.H.A. Mutsaers, X.F.D. Stragier TUE, Eindhoven, The Netherlands J. Marcos, E. Marín, R. Muñoz Horta, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain G. Taylor The University of Melbourne, Melbourne, Victoria, Australia
	Funding: This project has received funding from the European Union’s Horizon2020 research and innovation programme under grant agreement No 777431 The H₂020 CompactLight Project (www. CompactLight.eu) aims at designing the next generation of compact X-rays Free-Electron Lasers, relying on very high gradient accelerating structures (X-band, 12 GHz), the most advanced concepts for bright electron photo injectors, and innovative compact short-period undulators. Compared to existing facilities, the proposed facility will benefit from a lower electron beam energy, due to the enhanced undulators performance, and will be significantly more compact, with a smaller footprint, as a consequence of the lower energy and the high-gradient X-band structures. In addition, the whole infrastructure will also have a lower electrical power demand as well as lower construction and running costs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB032
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPTS024	Design of a Full C-Band Injector for Ultra-High Brightness Electron Beam	1979
	D. Alesini, F. Cardelli, G. Castorina, M. Croia, M. Diomede, M. Ferrario, A. Gallo, A. Giribono, B. Spataro, C. Vaccarezza, A. Vannozzi INFN/LNF, Frascati, Italy
	High gradient rf photo-injectors have been a key development to enable several applications of high quality electron beams. They allow the generation of beams with very high peak current and low transverse emittance, satisfying the tight demands for free-electron lasers, energy recovery linacs, Compton/Thomson sources and high-energy linear colliders. In the paper we present the design of a new full C-band RF photo-injector recently developed in the framework of the XLS-Compact Light design study and of the EuPRAXIA@SPARC_LAB proposal. It allows to reach extremely good beam performances in terms of beam emittance (at the level of few hundreds nm), energy spread and peak current. The photo-injector is based on a very high gradient (>200 MV/m) ultra-fast (RF pulses <200 ns) C-band RF gun, followed by two C band TW structures. Different types of couplers for the 1.6 cell RF gun have been considered and also a new compact low pulsed heating coupler working on the TM020 mode on the full cell has been proposed. In the paper we report the design criteria of the gun, the powering system, and the results of the beam dynamics simulations. We also discuss the case of 1 kHz repetition rate.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS024
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYPLS1	Building the Impedance Model of a Real Machine	2249
	B. Salvant, D. Amorim, S.A. Antipov, S. Arsenyev, M.S. Beck, N. Biancacci, O.S. Brüning, J.V. Campelo, E. Carideo, F. Caspers, A. Farricker, A. Grudiev, T. Kaltenbacher, E. Koukovini-Platia, P. Kramer, A. Lasheen, M. Migliorati, N. Mounet, E. Métral, N. Nasr Esfahani, S. Persichelli, B.K. Popovic, T.L. Rijoff, G. Rumolo, E.N. Shaposhnikova, V.G. Vaccaro, C. Vollinger, N. Wang, C. Zannini, B. Zotter CERN, Meyrin, Switzerland D. Amorim Grenoble-INP Phelma, Grenoble, France T. Dalascu EPFL, Lausanne, Switzerland M. Migliorati Sapienza University of Rome, Rome, Italy R. Nagaoka SOLEIL, Gif-sur-Yvette, France V.V. Smaluk BNL, Upton, Long Island, New York, USA B. Spataro INFN/LNF, Frascati, Italy N. Wang IHEP, Beijing, People’s Republic of China S.M. White ESRF, Grenoble, France
	A reliable impedance model of a particle accelerator can be built by combining the beam coupling impedances of all the components. This is a necessary step to be able to evaluate the machine performance limitations, identify the main contributors in case an impedance reduction is required, and study the interaction with other mechanisms such as optics nonlinearities, transverse damper, noise, space charge, electron cloud, beam-beam (in a collider). The main phases to create a realistic impedance model, and verify it experimentally, will be reviewed, highlighting the main challenges. Some examples will be presented revealing the levels of precision of machine impedance models that have been achieved.
	Slides WEYPLS1 [5.648 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYPLS1
About •	paper received ※ 10 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB020	Compact Ultra High-Gradient Ka-Band Accelerating Structure for Research, Medical and Industrial Applications	2842
	L. Faillace INFN-Milano, Milano, Italy M. Behtouei Sapienza University of Rome, Rome, Italy V.A. Dolgashev SLAC, Menlo Park, California, USA B. Spataro, A. Variola INFN/LNF, Frascati, Italy G. Torrisi INFN/LNS, Catania, Italy
	Technological advancements are strongly required to fulfil demands for new accelerators devices from the compact or portable devices for radiotherapy to mo-bile cargo inspections and security, biology, energy and environmental applications, and ultimately for the next generation of colliders. In the frame of the collab-oration with INFN-LNF, SLAC (USA) we are working closely on design studies, fabrication and high-power operation of Ka-band accelerating structures. In par-ticular, new manufacturing techniques for hard-copper structures are being investigated in order to determine the maximum sustainable gradients above 150 MV/m and extremely low probability of RF breakdown. In this paper, the preliminary RF and mechanical design as well as beam dynamics estimations for a Ka-Band accelerating structure at 35 GHz are presented together with discussions on practical accelerating gradients and maximum average beam current throughput.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB020
About •	paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB024	Low Power RF Test of a Quadrupole-free X-Band Mode Launcher for High Brightness Applications	2856
	G. Torrisi, L. Celona, S. Gammino, O. Leonardi, G. Sorbello INFN/LNS, Catania, Italy G. Castorina Sapienza University of Rome, Rome, Italy V.A. Dolgashev SLAC, Menlo Park, California, USA L. Faillace INFN-Milano, Milano, Italy G.S. Mauro INFN/LNL, Legnaro (PD), Italy G. Sorbello University of Catania, Catania, Italy B. Spataro INFN/LNF, Frascati, Italy
	In this work we present the low power RF characterization of a novel TM01 X-band mode launcher for the new generation of high brightness RF photo-injectors. The proposed mode launcher exploits a fourfold symmetry which minimizes both the dipole and the quadrupole fields in order to mitigate the emittance growth in the early stages of the acceleration process. Two identical aluminum mode launchers have been assembled and measured in back-to-back configurations for three different central waveguide lengths. From the back-to-back results we infer the performance of each mode launcher. The low power RF test, performed at the Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS), validate both the numerical simulations and the quality of fabrication. An oxygen-free high-conductivity copper version of the device is being manufactured for high power and ultra high vacuum tests that are planned to be conducted at SLAC
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB024
About •	paper received ※ 09 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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THPGW080	Initial Results of High-Gradient Breakdown Tests for W-Band Accelerating Structures	3769
	M.A.K. Othman, V.A. Dolgashev, A.A. Haase, E.A. Nanni, J. Neilson, S.G. Tantawi SLAC, Menlo Park, California, USA S. Jawla, J.F. Picard, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA S.C. Schaub MIT, Cambridge, Massachusetts, USA B. Spataro INFN/LNF, Frascati, Italy
	Funding: This work was supported by Department of Energy contract DE-AC02-76SF00515 (SLAC) and grant DE-SC0015566 (MIT). This work was also supported by NSF grants PHY-1734015. Emerging accelerator technology at mm-wave and THz frequencies has recently shown notable progress. Indeed, metallic and dielectric accelerating structures at THz frequencies are plausible candidates toward miniaturization of accelerators. RF breakdown in such structures is a major factor limiting their performance. Therefore, comprehensive analysis of RF breakdown physics in mm-wave accelerating structures is needed, which includes understanding of dependencies of the breakdown rate on geometric, electromagnetic and material properties. In this work we report on high power tests of a 110 GHz single-cell standing wave accelerating structure powered by a 1 MW gyrotron. The RF power is coupled from the gyrotron into the accelerating structure with a Gaussian to TM01 mode converter through a quasi-optical setup. We demonstrate coupling of 10 ns, 100s of kilowatt pulses into the structure using a fast switch and achieving ~150 MV/m accelerating gradients. Measurements of RF signals and field-emitted currents allow for complete comprehensive of the high-gradient behavior of W-band structures, including breakdown probability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW080
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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Paper

Title

Page

MOPGW030

New Analytical Derivation of Group Velocity in TW Accelerating Structures

155

SUSPFO035

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

M. Behtouei, M. Migliorati, L. Palumbo
Sapienza University of Rome, Rome, Italy
L. Faillace
Universita’ degli Studi di Milano & INFN, Milano, Italy
B. Spataro
INFN/LNF, Frascati, Italy

Ultra high-gradient accelerating structures are needed for the next generation of compact light sources. In the framework of the Compact Light XLS project, we are studying a high harmonic traveling-wave accelerating structure operating at a frequency of 35.982 GHz, in order to linearize the longitudinal space phase. In this paper, we propose a new analytical approach for the estimation of the group velocity in the structure and we compare it with numerical electromagnetic simulations that are carried out by using the code HFSS in the frequency domain.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW030

About •

paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

TUXXPLM3

First Operation of a Hybrid e-Gun at the Schlesinger Center for Compact Accelerators in Ariel University

1171

A.N. Nause, A. Fukasawa, J.B. Rosenzweig, R.J. Roussel
UCLA, Los Angeles, USA
A. Friedman
Ariel University, Ariel, Israel
B. Spataro
INFN/LNF, Frascati, Italy

Funding: Israel Ministry of Defence Israel Ministry of Science
A novel hybrid photo injector was designed and partially tested at the UCLA Particle Beam Physics Laboratory. It was later commissioned at Ariel University in Israel as an on-going collaboration between the two universities. This unique, new generation design provides a radically simpler approach to RF feeding of a gun/buncher system, leading to a much shorter beam via velocity bunching owed to an attached traveling wave section of the photo-injector. This design results in better performance in beam parameters, providing a high quality electron beam, with energy of 6 MeV, emittance of app 3 μm, and a 150 fs pulse duration at up to 1 nC per pulse. The Hybrid gun is driven by a SLAC XK5 Klystron as the high power RF source, and third harmonic of a fs level IR Laser amplifier (266 nm) to drive the Cathode. The unique e-gun will produce an electron pulse for a THz FEL, which will operate at the super-radiance regime, and therefore requires extraordinary beam properties. This paper briefly describes the gun and presents initial operational results from the gun and its sub-systems.

Slides TUXXPLM3 [9.526 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUXXPLM3

About •

paper received ※ 14 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

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

TUPRB032

The CompactLight Design Study Project

1756

G. D’Auria, S. Di Mitri, R.A. Rochow
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
M. Aicheler
HIP, University of Helsinki, Finland
A.A. Aksoy
Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
D. Alesini, M. Bellaveglia, B. Buonomo, F. Cardelli, M. Croia, M. Diomede, M. Ferrario, A. Gallo, A. Giribono, L. Piersanti, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati, Italy
R. Apsimon, A. Castilla
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
J.M. Arnesano, F. Bosco, L. Ficcadenti, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
A. Bernhard, J. Gethmann
KIT, Karlsruhe, Germany
G. Burt
Lancaster University, Lancaster, United Kingdom
M. Calvi, T. Schmidt, K. Zhang
PSI, Villigen PSI, Switzerland
H.M. Castaneda Cortes, J.A. Clarke, D.J. Dunning, N. Thompson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A.W. Cross, L. Zhang
USTRAT/SUPA, Glasgow, United Kingdom
G. Dattoli, F. Nguyen, A. Petralia
ENEA C.R. Frascati, Frascati (Roma), Italy
R.T. Dowd, D. Zhu
AS - ANSTO, Clayton, Australia
W.D. Fang
SINAP, Shanghai, People’s Republic of China
A. Faus-Golfe, Y. Han
LAL, Orsay, France
E.N. Gazis, N. Gazis
National Technical University of Athens, Zografou, Greece
R. Geometrante, M. Kokole
KYMA, Trieste, Italy
V.A. Goryashko, M. Jacewicz, R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
X.J.A. Janssen, J.M.A. Priem
VDL ETG, Eindhoven, The Netherlands
A. Latina, X. Liu, C. Rossi, D. Schulte, S. Stapnes, X.W. Wu, W. Wuensch
CERN, Geneva, Switzerland
O.J. Luiten, P.H.A. Mutsaers, X.F.D. Stragier
TUE, Eindhoven, The Netherlands
J. Marcos, E. Marín, R. Muñoz Horta, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
G. Taylor
The University of Melbourne, Melbourne, Victoria, Australia

Funding: This project has received funding from the European Union’s Horizon2020 research and innovation programme under grant agreement No 777431
The H₂020 CompactLight Project (www. CompactLight.eu) aims at designing the next generation of compact X-rays Free-Electron Lasers, relying on very high gradient accelerating structures (X-band, 12 GHz), the most advanced concepts for bright electron photo injectors, and innovative compact short-period undulators. Compared to existing facilities, the proposed facility will benefit from a lower electron beam energy, due to the enhanced undulators performance, and will be significantly more compact, with a smaller footprint, as a consequence of the lower energy and the high-gradient X-band structures. In addition, the whole infrastructure will also have a lower electrical power demand as well as lower construction and running costs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB032

About •

paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

Export •

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

TUPTS024

Design of a Full C-Band Injector for Ultra-High Brightness Electron Beam

1979

D. Alesini, F. Cardelli, G. Castorina, M. Croia, M. Diomede, M. Ferrario, A. Gallo, A. Giribono, B. Spataro, C. Vaccarezza, A. Vannozzi
INFN/LNF, Frascati, Italy

High gradient rf photo-injectors have been a key development to enable several applications of high quality electron beams. They allow the generation of beams with very high peak current and low transverse emittance, satisfying the tight demands for free-electron lasers, energy recovery linacs, Compton/Thomson sources and high-energy linear colliders. In the paper we present the design of a new full C-band RF photo-injector recently developed in the framework of the XLS-Compact Light design study and of the EuPRAXIA@SPARC_LAB proposal. It allows to reach extremely good beam performances in terms of beam emittance (at the level of few hundreds nm), energy spread and peak current. The photo-injector is based on a very high gradient (>200 MV/m) ultra-fast (RF pulses <200 ns) C-band RF gun, followed by two C band TW structures. Different types of couplers for the 1.6 cell RF gun have been considered and also a new compact low pulsed heating coupler working on the TM020 mode on the full cell has been proposed. In the paper we report the design criteria of the gun, the powering system, and the results of the beam dynamics simulations. We also discuss the case of 1 kHz repetition rate.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS024

About •

paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

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

WEYPLS1

Building the Impedance Model of a Real Machine

2249

B. Salvant, D. Amorim, S.A. Antipov, S. Arsenyev, M.S. Beck, N. Biancacci, O.S. Brüning, J.V. Campelo, E. Carideo, F. Caspers, A. Farricker, A. Grudiev, T. Kaltenbacher, E. Koukovini-Platia, P. Kramer, A. Lasheen, M. Migliorati, N. Mounet, E. Métral, N. Nasr Esfahani, S. Persichelli, B.K. Popovic, T.L. Rijoff, G. Rumolo, E.N. Shaposhnikova, V.G. Vaccaro, C. Vollinger, N. Wang, C. Zannini, B. Zotter
CERN, Meyrin, Switzerland
D. Amorim
Grenoble-INP Phelma, Grenoble, France
T. Dalascu
EPFL, Lausanne, Switzerland
M. Migliorati
Sapienza University of Rome, Rome, Italy
R. Nagaoka
SOLEIL, Gif-sur-Yvette, France
V.V. Smaluk
BNL, Upton, Long Island, New York, USA
B. Spataro
INFN/LNF, Frascati, Italy
N. Wang
IHEP, Beijing, People’s Republic of China
S.M. White
ESRF, Grenoble, France

A reliable impedance model of a particle accelerator can be built by combining the beam coupling impedances of all the components. This is a necessary step to be able to evaluate the machine performance limitations, identify the main contributors in case an impedance reduction is required, and study the interaction with other mechanisms such as optics nonlinearities, transverse damper, noise, space charge, electron cloud, beam-beam (in a collider). The main phases to create a realistic impedance model, and verify it experimentally, will be reviewed, highlighting the main challenges. Some examples will be presented revealing the levels of precision of machine impedance models that have been achieved.

Slides WEYPLS1 [5.648 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYPLS1

About •

paper received ※ 10 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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

WEPRB020

Compact Ultra High-Gradient Ka-Band Accelerating Structure for Research, Medical and Industrial Applications

2842

L. Faillace
INFN-Milano, Milano, Italy
M. Behtouei
Sapienza University of Rome, Rome, Italy
V.A. Dolgashev
SLAC, Menlo Park, California, USA
B. Spataro, A. Variola
INFN/LNF, Frascati, Italy
G. Torrisi
INFN/LNS, Catania, Italy

Technological advancements are strongly required to fulfil demands for new accelerators devices from the compact or portable devices for radiotherapy to mo-bile cargo inspections and security, biology, energy and environmental applications, and ultimately for the next generation of colliders. In the frame of the collab-oration with INFN-LNF, SLAC (USA) we are working closely on design studies, fabrication and high-power operation of Ka-band accelerating structures. In par-ticular, new manufacturing techniques for hard-copper structures are being investigated in order to determine the maximum sustainable gradients above 150 MV/m and extremely low probability of RF breakdown. In this paper, the preliminary RF and mechanical design as well as beam dynamics estimations for a Ka-Band accelerating structure at 35 GHz are presented together with discussions on practical accelerating gradients and maximum average beam current throughput.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB020

About •

paper received ※ 08 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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

WEPRB024

Low Power RF Test of a Quadrupole-free X-Band Mode Launcher for High Brightness Applications

2856

G. Torrisi, L. Celona, S. Gammino, O. Leonardi, G. Sorbello
INFN/LNS, Catania, Italy
G. Castorina
Sapienza University of Rome, Rome, Italy
V.A. Dolgashev
SLAC, Menlo Park, California, USA
L. Faillace
INFN-Milano, Milano, Italy
G.S. Mauro
INFN/LNL, Legnaro (PD), Italy
G. Sorbello
University of Catania, Catania, Italy
B. Spataro
INFN/LNF, Frascati, Italy

In this work we present the low power RF characterization of a novel TM01 X-band mode launcher for the new generation of high brightness RF photo-injectors. The proposed mode launcher exploits a fourfold symmetry which minimizes both the dipole and the quadrupole fields in order to mitigate the emittance growth in the early stages of the acceleration process. Two identical aluminum mode launchers have been assembled and measured in back-to-back configurations for three different central waveguide lengths. From the back-to-back results we infer the performance of each mode launcher. The low power RF test, performed at the Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS), validate both the numerical simulations and the quality of fabrication. An oxygen-free high-conductivity copper version of the device is being manufactured for high power and ultra high vacuum tests that are planned to be conducted at SLAC

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB024

About •

paper received ※ 09 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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THPGW080

Initial Results of High-Gradient Breakdown Tests for W-Band Accelerating Structures

3769

M.A.K. Othman, V.A. Dolgashev, A.A. Haase, E.A. Nanni, J. Neilson, S.G. Tantawi
SLAC, Menlo Park, California, USA
S. Jawla, J.F. Picard, R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA
S.C. Schaub
MIT, Cambridge, Massachusetts, USA
B. Spataro
INFN/LNF, Frascati, Italy

Funding: This work was supported by Department of Energy contract DE-AC02-76SF00515 (SLAC) and grant DE-SC0015566 (MIT). This work was also supported by NSF grants PHY-1734015.
Emerging accelerator technology at mm-wave and THz frequencies has recently shown notable progress. Indeed, metallic and dielectric accelerating structures at THz frequencies are plausible candidates toward miniaturization of accelerators. RF breakdown in such structures is a major factor limiting their performance. Therefore, comprehensive analysis of RF breakdown physics in mm-wave accelerating structures is needed, which includes understanding of dependencies of the breakdown rate on geometric, electromagnetic and material properties. In this work we report on high power tests of a 110 GHz single-cell standing wave accelerating structure powered by a 1 MW gyrotron. The RF power is coupled from the gyrotron into the accelerating structure with a Gaussian to TM01 mode converter through a quasi-optical setup. We demonstrate coupling of 10 ns, 100s of kilowatt pulses into the structure using a fast switch and achieving ~150 MV/m accelerating gradients. Measurements of RF signals and field-emitted currents allow for complete comprehensive of the high-gradient behavior of W-band structures, including breakdown probability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW080

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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