IPAC2017 - Table of Session: THOBB (Contributed Oral Presentations, Accelerator Technology)

Paper	Title	Page
THOBB1	High Power Test Results of the Eli-NP S-Band Gun Fabricated with the New Clamping Technology Without Brazing	3662
	D. Alesini, A. Battisti, M. Bellaveglia, A. Falone, A. Gallo, V.L. Lollo, L. Pellegrino, S. Pioli, S. Tomassini, A. Variola INFN/LNF, Frascati (Roma), Italy F. Cardelli, L. Palumbo University of Rome La Sapienza, Rome, Italy L. Ficcadenti, V. Pettinacci INFN-Roma, Roma, Italy D.T. Palmer Istituto Nazionale di Fisica Nucleare, Milano, Italy L. Piersanti INFN-Roma1, Rome, Italy
	High gradient RF photoguns 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. A new fabrication technique for this type of structures has been recently developed and implemented at the Laboratories of the National Institute of Nuclear physics in Frascati (LNF-INFN, Italy). It is based on the use of special RF-vacuum gaskets that allow avoiding brazing in the realization process. The S-band gun of the Compton-based ELI-NP gamma beam system (GBS) has been fabricated with this new technique. It operates at 100 Hz with 120 MV/m cathode peak field and long RF pulses to allow the 32 bunch generation foreseen for the GBS. High gradient tests have been performed at full power full repetition rate and have shown the extremely good performances of the structure in term of breakdown rates. In the paper we report and discuss all experimental results with details of the electromagnetic design and mechanical realization processes.
	Slides THOBB1 [6.211 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THOBB1
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THOBB2	Plasma Processing R&D for LCLS-II Cavities
	M. Martinello, S. Aderhold, P. Berrutti, A. Grassellino, T.N. Khabiboulline Fermilab, Batavia, Illinois, USA A. Burrill, D. Gonnella, G. Lanza, C.-K. Ng, M.C. Ross, L. Xiao SLAC, Menlo Park, California, USA M. Doleans ORNL, Oak Ridge, Tennessee, USA
	Field emission is one the major limitations to the maximum usable accelerating gradient of SRF cavities in cryomodules. Taking advantage of the plasma chemistry, field emitting particles may be preferentially attacked with the purpose of modifying the work function, smoothing the particle shape or even removing completely the field emitter. Relying on this idea, a collaboration between FNAL, SLAC and ORNL was established with the purpose of building a plasma processing system as a tool capable to minimize and overcome the problem of field emission in LCLS-II cryomodules. The plasma processing system is inspired to the one already built at the Spallation Neutron Source (SNS), that is capable to process in-situ cavities from hydrocarbon contaminants, by means of a neon-oxygen reactive plasma mixture. Here we show an innovative RF design that has been optimized in order to ignite the plasma using a mixture of fundamental pass-band and high order modes. In addition, the first results obtained on contaminated samples and single-cell cavities are shown together with the future plan of the project.
	Slides THOBB2 [9.433 MB]
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THOBB3	ESS SRF Linear Accelerator Components Preliminary Results and Integration	3666
	C. Darve, N. Elias, C.G. Maiano, F. Schlander ESS, Lund, Sweden C. Arcambal, G. Devanz, F. Peauger CEA/DRF/IRFU, Gif-sur-Yvette, France E. Cenni CEA/IRFU, Gif-sur-Yvette, France G. Costanza Lund University, Lund, Sweden P. Duthil, G. Olry, D. Reynet IPN, Orsay, France L. Hermansson Uppsala University, Uppsala, Sweden P. Michelato, D. Sertore INFN/LASA, Segrate (MI), Italy
	The European Spallation Source (ESS) is a pan-European project and one of world's largest research infrastructures based on neutron sources. This collaborative project is funded by a collaboration of 17 European countries and is under construction in Lund, Sweden. The 5 MW, 2.86 ms long pulse proton accelerator has a repetition frequency of 14 Hz (4 % duty cycle), and a beam current of 62.5 mA. The Superconducting Radio-Frequency (SRF) linac is composed of three families of Superconducting Radio-Frequency (SRF) cavities, which are being prototyped, counting the spoke resonators with a geometric beta of 0.5, medium-beta elliptical cavities (beta_g=0.67) and high-beta elliptical cavities (beta_g=0.86). After a description of the ESS linear accelerator layout, this article will focus on the recent progress towards integration of the first test results of the main critical components to be assembled in cryomodules, then in the ESS tunnel.
	Slides THOBB3 [25.611 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THOBB3
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

High Power Test Results of the Eli-NP S-Band Gun Fabricated with the New Clamping Technology Without Brazing

3662

D. Alesini, A. Battisti, M. Bellaveglia, A. Falone, A. Gallo, V.L. Lollo, L. Pellegrino, S. Pioli, S. Tomassini, A. Variola
INFN/LNF, Frascati (Roma), Italy
F. Cardelli, L. Palumbo
University of Rome La Sapienza, Rome, Italy
L. Ficcadenti, V. Pettinacci
INFN-Roma, Roma, Italy
D.T. Palmer
Istituto Nazionale di Fisica Nucleare, Milano, Italy
L. Piersanti
INFN-Roma1, Rome, Italy

High gradient RF photoguns 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. A new fabrication technique for this type of structures has been recently developed and implemented at the Laboratories of the National Institute of Nuclear physics in Frascati (LNF-INFN, Italy). It is based on the use of special RF-vacuum gaskets that allow avoiding brazing in the realization process. The S-band gun of the Compton-based ELI-NP gamma beam system (GBS) has been fabricated with this new technique. It operates at 100 Hz with 120 MV/m cathode peak field and long RF pulses to allow the 32 bunch generation foreseen for the GBS. High gradient tests have been performed at full power full repetition rate and have shown the extremely good performances of the structure in term of breakdown rates. In the paper we report and discuss all experimental results with details of the electromagnetic design and mechanical realization processes.

Slides THOBB1 [6.211 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THOBB1

Export •

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

THOBB2

Plasma Processing R&D for LCLS-II Cavities

M. Martinello, S. Aderhold, P. Berrutti, A. Grassellino, T.N. Khabiboulline
Fermilab, Batavia, Illinois, USA
A. Burrill, D. Gonnella, G. Lanza, C.-K. Ng, M.C. Ross, L. Xiao
SLAC, Menlo Park, California, USA
M. Doleans
ORNL, Oak Ridge, Tennessee, USA

Field emission is one the major limitations to the maximum usable accelerating gradient of SRF cavities in cryomodules. Taking advantage of the plasma chemistry, field emitting particles may be preferentially attacked with the purpose of modifying the work function, smoothing the particle shape or even removing completely the field emitter. Relying on this idea, a collaboration between FNAL, SLAC and ORNL was established with the purpose of building a plasma processing system as a tool capable to minimize and overcome the problem of field emission in LCLS-II cryomodules. The plasma processing system is inspired to the one already built at the Spallation Neutron Source (SNS), that is capable to process in-situ cavities from hydrocarbon contaminants, by means of a neon-oxygen reactive plasma mixture. Here we show an innovative RF design that has been optimized in order to ignite the plasma using a mixture of fundamental pass-band and high order modes. In addition, the first results obtained on contaminated samples and single-cell cavities are shown together with the future plan of the project.

Slides THOBB2 [9.433 MB]

Export •

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

THOBB3

ESS SRF Linear Accelerator Components Preliminary Results and Integration

3666

C. Darve, N. Elias, C.G. Maiano, F. Schlander
ESS, Lund, Sweden
C. Arcambal, G. Devanz, F. Peauger
CEA/DRF/IRFU, Gif-sur-Yvette, France
E. Cenni
CEA/IRFU, Gif-sur-Yvette, France
G. Costanza
Lund University, Lund, Sweden
P. Duthil, G. Olry, D. Reynet
IPN, Orsay, France
L. Hermansson
Uppsala University, Uppsala, Sweden
P. Michelato, D. Sertore
INFN/LASA, Segrate (MI), Italy

The European Spallation Source (ESS) is a pan-European project and one of world's largest research infrastructures based on neutron sources. This collaborative project is funded by a collaboration of 17 European countries and is under construction in Lund, Sweden. The 5 MW, 2.86 ms long pulse proton accelerator has a repetition frequency of 14 Hz (4 % duty cycle), and a beam current of 62.5 mA. The Superconducting Radio-Frequency (SRF) linac is composed of three families of Superconducting Radio-Frequency (SRF) cavities, which are being prototyped, counting the spoke resonators with a geometric beta of 0.5, medium-beta elliptical cavities (beta_g=0.67) and high-beta elliptical cavities (beta_g=0.86). After a description of the ESS linear accelerator layout, this article will focus on the recent progress towards integration of the first test results of the main critical components to be assembled in cryomodules, then in the ESS tunnel.

Slides THOBB3 [25.611 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THOBB3

Export •

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