IPAC2018 - List of Authors (Spataro, B.)

Paper	Title	Page
TUZGBE4	Toward High-Power High-Gradient Testing of mm-Wave Standing-Wave Accelerating Structures	1224
	E.A. Nanni, V.A. Dolgashev, A.A. Haase, J. Neilson, S.G. Tantawi SLAC, Menlo Park, California, USA S. Jawla, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA S. C. Schaub MIT, Cambridge, Massachusetts, USA B. Spataro INFN/LNF, Frascati (Roma), Italy
	Funding: This work is supported in part by Department of Energy contract DE-AC02-76SF00515 (SLAC) and DE-SC0015566 (MIT). We will preliminary testing results for single-cell accelerating structures intended for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures consist of pi-mode standing-wave cavities fed with TM01 circular waveguide mode. We fabricated of two structures one in copper and the other in CuAg alloy. Cold RF tests confirm the design RF performance of the structures. The geometry and field shape of these accelerating structures is as close as practical to single-cell standing-wave X-band accelerating structures more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. The structures will be powered with a MW gyrotron oscillator that produces microsecond pulses. One megawatt of RF power from the gyrotron may allow us to reach a peak accelerating gradient of 400 MeV/m.
	Slides TUZGBE4 [4.644 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBE4
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THPAK052	Single Bunch Instabilities in FCC-ee	3336
SUSPF076	use link to see paper's listing under its alternate paper code
	E. Belli Sapienza University of Rome, Rome, Italy G. Castorina, M. Migliorati INFN-Roma1, Rome, Italy G. Rumolo CERN, Geneva, Switzerland B. Spataro, M. Zobov INFN/LNF, Frascati (Roma), Italy
	FCC-ee is a high luminosity lepton collider with a centre-of-mass energy from 91 to 365 GeV. Due to the machine parameters and pipe dimensions, collective effects due to electromagnetic fields produced by the interaction of the beam with the vacuum chamber can be one of the main limitations to the machine performance. In this frame, an impedance model is required to analyze these instabilities and to find possible solutions for their mitigation. This paper will present the contributions of specific machine components to the total impedance budget and their effects on the beam stability. Single bunch instability thresholds will be estimated in both transverse and longitudinal planes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK052
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THPAL009	A TM01 Mode Launcher With Quadrupole Field Components Cancellation for High Brightness Applications	3631
	G. Castorina INFN-Roma1, Rome, Italy A.D. Cahill, J.B. Rosenzweig UCLA, Los Angeles, California, USA F. Cardelli, G. Franzini, A. Marcelli, B. Spataro INFN/LNF, Frascati (Roma), Italy L. Celona, S. Gammino, G. Torrisi INFN/LNS, Catania, Italy V.A. Dolgashev SLAC, Menlo Park, California, USA L. Ficcadenti Rome University La Sapienza, Roma, Italy M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy G. Sorbello University of Catania, Catania, Italy
	The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL009
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THPMK058	RF Design of the X-band Linac for the EuPRAXIA@SPARC_LAB Project	4422
SUSPF016	use link to see paper's listing under its alternate paper code
	M. Diomede Sapienza University of Rome, Rome, Italy D. Alesini, M. Bellaveglia, B. Buonomo, F. Cardelli, E. Chiadroni, G. Di Raddo, R.D. Di Raddo, M. Diomede, M. Ferrario, A. Gallo, A. Ghigo, A. Giribono, V.L. Lollo, L. Piersanti, B. Spataro, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy N. Catalán Lasheras, A. Grudiev, W. Wuensch CERN, Geneva, Switzerland
	We illustrate the RF design of the X-band linac for the upgrade of the SPARC_LAB facility at INFN-LNF (EuPRAXIA@SPARC_LAB). The structures are travelling wave (TW) cavities, working on the 2π/3 mode, fed by klystrons with pulse compressor systems. The tapering of the cells along the structure and the cell profiles have been optimized to maximize the effective shunt impedance keeping under control the maximum value of the modified Poynting vector, while the couplers have been designed to have a symmetric feeding and a reduced pulsed heating. In the paper we also present the RF power distribution layout of the accelerating module and a preliminary mechanical design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK058
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Paper

Title

Page

Toward High-Power High-Gradient Testing of mm-Wave Standing-Wave Accelerating Structures

1224

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

Funding: This work is supported in part by Department of Energy contract DE-AC02-76SF00515 (SLAC) and DE-SC0015566 (MIT).
We will preliminary testing results for single-cell accelerating structures intended for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures consist of pi-mode standing-wave cavities fed with TM01 circular waveguide mode. We fabricated of two structures one in copper and the other in CuAg alloy. Cold RF tests confirm the design RF performance of the structures. The geometry and field shape of these accelerating structures is as close as practical to single-cell standing-wave X-band accelerating structures more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. The structures will be powered with a MW gyrotron oscillator that produces microsecond pulses. One megawatt of RF power from the gyrotron may allow us to reach a peak accelerating gradient of 400 MeV/m.

Slides TUZGBE4 [4.644 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBE4

Export •

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

THPAK052

Single Bunch Instabilities in FCC-ee

3336

SUSPF076

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

E. Belli
Sapienza University of Rome, Rome, Italy
G. Castorina, M. Migliorati
INFN-Roma1, Rome, Italy
G. Rumolo
CERN, Geneva, Switzerland
B. Spataro, M. Zobov
INFN/LNF, Frascati (Roma), Italy

FCC-ee is a high luminosity lepton collider with a centre-of-mass energy from 91 to 365 GeV. Due to the machine parameters and pipe dimensions, collective effects due to electromagnetic fields produced by the interaction of the beam with the vacuum chamber can be one of the main limitations to the machine performance. In this frame, an impedance model is required to analyze these instabilities and to find possible solutions for their mitigation. This paper will present the contributions of specific machine components to the total impedance budget and their effects on the beam stability. Single bunch instability thresholds will be estimated in both transverse and longitudinal planes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK052

Export •

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

THPAL009

A TM01 Mode Launcher With Quadrupole Field Components Cancellation for High Brightness Applications

3631

G. Castorina
INFN-Roma1, Rome, Italy
A.D. Cahill, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
F. Cardelli, G. Franzini, A. Marcelli, B. Spataro
INFN/LNF, Frascati (Roma), Italy
L. Celona, S. Gammino, G. Torrisi
INFN/LNS, Catania, Italy
V.A. Dolgashev
SLAC, Menlo Park, California, USA
L. Ficcadenti
Rome University La Sapienza, Roma, Italy
M. Migliorati, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
G. Sorbello
University of Catania, Catania, Italy

The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL009

Export •

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

THPMK058

RF Design of the X-band Linac for the EuPRAXIA@SPARC_LAB Project

4422

SUSPF016

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

M. Diomede
Sapienza University of Rome, Rome, Italy
D. Alesini, M. Bellaveglia, B. Buonomo, F. Cardelli, E. Chiadroni, G. Di Raddo, R.D. Di Raddo, M. Diomede, M. Ferrario, A. Gallo, A. Ghigo, A. Giribono, V.L. Lollo, L. Piersanti, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
N. Catalán Lasheras, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland

We illustrate the RF design of the X-band linac for the upgrade of the SPARC_LAB facility at INFN-LNF (EuPRAXIA@SPARC_LAB). The structures are travelling wave (TW) cavities, working on the 2π/3 mode, fed by klystrons with pulse compressor systems. The tapering of the cells along the structure and the cell profiles have been optimized to maximize the effective shunt impedance keeping under control the maximum value of the modified Poynting vector, while the couplers have been designed to have a symmetric feeding and a reduced pulsed heating. In the paper we also present the RF power distribution layout of the accelerating module and a preliminary mechanical design.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK058

Export •

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