IPAC2021 - List of Authors (Sauza-Bedolla, J.)

Paper	Title	Page
MOPAB142	A Compact, Low-Field, Broadband Matching Section for Externally-Powered X-Band Dielectric-Loaded Accelerating Structures	495
	Y. Wei, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom H. Bursali Sapienza University of Rome, Rome, Italy N. Catalán Lasheras, S. Gonzalez Anton, A. Grudiev, R. Wegner, Y. Wei CERN, Meyrin, Switzerland B.T. Freemire, C.-J. Jing Euclid TechLabs, Solon, Ohio, USA J. Sauza-Bedolla Lancaster University, Lancaster, United Kingdom Y. Wei, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	It has been technically challenging to efficiently couple external radiofrequency (RF) power to cylindrical dielectric-loaded accelerating (DLA) structures. This is especially true when the DLA structure has a high dielectric constant. This contribution presents a novel design of a matching section for coupling the RF power from a circular waveguide to an X-band DLA structure with a dielectric constant ε_r=16.66 and a loss tangent \tanθ = 3.43× 10^-5. It consists of a very compact dielectric disk with a width of 2.035 mm and a tilt angle of 60 degrees, resulting in a broadband coupling at a low RF field which has the potential to survive in the high-power environment. To prevent a sharp dielectric corner break, a 45-degree chamfer is added. Moreover, a microscale vacuum gap, caused by metallic clamping between the thin coating and the outer thick copper jacket, is studied in detail. Based on simulation studies, a prototype of the DLA structure with the matching sections was fabricated. Results from preliminary bench measurements and their comparison with design values will also be discussed.
	Poster MOPAB142 [2.617 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB142
About •	paper received ※ 11 May 2021 paper accepted ※ 21 May 2021 issue date ※ 19 August 2021
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MOPAB370	X-Band RF Spiral Load Optimization for Additive Manufacturing Mass Production	1143
	H. Bursali Sapienza University of Rome, Rome, Italy N. Catalán Lasheras, R.L. Gerard, A. Grudiev, O. Gumenyuk, P. Morales Sanchez, B. Riffaud CERN, Geneva, Switzerland J. Sauza-Bedolla Lancaster University, Lancaster, United Kingdom
	The CLIC main linac uses X-band traveling-wave normal conducting accelerating structures. The RF power not used for beam acceleration nor dissipated in the resistive wall is absorbed in two high power RF loads that should be as compact as possible to minimize the total footprint of the machine. In recent years, CERN has designed, fabricated and successfully tested several loads produced by additive manufacturing. With the current design, only one load can be produced in the 3D printing machine at a time. The aim of this study is optimizing the internal cross-section of loads in order to create a stackable design to increase the number of produced parts per manufacturing cycle and thus decrease the unit price. This paper presents the new design with an optimization of the internal vacuum part of the so-called RF spiral load. In this case, RF and mechanical designs were carried out in parallel. The new cross section has showed good RF reflection reaching less than -30 dB in simulations. The final load is now ready to be manufactured and high-power tested. This new load will not only provide cost saving but also faster manufacturing for mass production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB370
About •	paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 23 August 2021
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WEPAB416	Industrialization Study of the Accelerating Structures for a 380 GeV Compact Linear Collider	3674
	A. Magazinik Tampere University, Tampere, Finland N. Catalán Lasheras CERN, Meyrin, Switzerland S. Mäkinen Tampere University of Technology, Tampere, Finland J. Sauza-Bedolla Lancaster University, Lancaster, United Kingdom
	The LHC at CERN will continue its operation for approximately 20 years. In parallel, diverse studies are conducted for the design of a future large-scale accelerator. One of the options is the Compact Linear Collider (CLIC) who aims to provide a very high accelerating gradient (100 MV/m) achieved by using normal conducting radiofrequency (RF) cavities operating in the X-band range (12 GHz). Each accelerating structure is a challenging component involving ultra-precise machining and diffusion bonding techniques. The first stage of CLIC operates at a collision energy of 380 GeV with an accelerator length of 11 km, consisting of 21630 accelerating structures. Even though the prototypes have shown a mature and ready to build concept, the present number of qualified suppliers is limited. Therefore, an industrialization study was done through a technical survey with hi-tech companies. The aim is to evaluate current capabilities, to ensure the necessary manufacturing yield, schedule, and cost for mass production. This paper presents the results of the industrialization study for 12 GHz accelerating structures for CLIC 380 GeV, highlighting the principal challenges towards mass production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB416
About •	paper received ※ 19 May 2021 paper accepted ※ 22 June 2021 issue date ※ 14 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

A Compact, Low-Field, Broadband Matching Section for Externally-Powered X-Band Dielectric-Loaded Accelerating Structures

495

Y. Wei, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
H. Bursali
Sapienza University of Rome, Rome, Italy
N. Catalán Lasheras, S. Gonzalez Anton, A. Grudiev, R. Wegner, Y. Wei
CERN, Meyrin, Switzerland
B.T. Freemire, C.-J. Jing
Euclid TechLabs, Solon, Ohio, USA
J. Sauza-Bedolla
Lancaster University, Lancaster, United Kingdom
Y. Wei, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

It has been technically challenging to efficiently couple external radiofrequency (RF) power to cylindrical dielectric-loaded accelerating (DLA) structures. This is especially true when the DLA structure has a high dielectric constant. This contribution presents a novel design of a matching section for coupling the RF power from a circular waveguide to an X-band DLA structure with a dielectric constant ε_r=16.66 and a loss tangent \tanθ = 3.43× 10^-5. It consists of a very compact dielectric disk with a width of 2.035 mm and a tilt angle of 60 degrees, resulting in a broadband coupling at a low RF field which has the potential to survive in the high-power environment. To prevent a sharp dielectric corner break, a 45-degree chamfer is added. Moreover, a microscale vacuum gap, caused by metallic clamping between the thin coating and the outer thick copper jacket, is studied in detail. Based on simulation studies, a prototype of the DLA structure with the matching sections was fabricated. Results from preliminary bench measurements and their comparison with design values will also be discussed.

Poster MOPAB142 [2.617 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB142

About •

paper received ※ 11 May 2021 paper accepted ※ 21 May 2021 issue date ※ 19 August 2021

Export •

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

MOPAB370

X-Band RF Spiral Load Optimization for Additive Manufacturing Mass Production

1143

H. Bursali
Sapienza University of Rome, Rome, Italy
N. Catalán Lasheras, R.L. Gerard, A. Grudiev, O. Gumenyuk, P. Morales Sanchez, B. Riffaud
CERN, Geneva, Switzerland
J. Sauza-Bedolla
Lancaster University, Lancaster, United Kingdom

The CLIC main linac uses X-band traveling-wave normal conducting accelerating structures. The RF power not used for beam acceleration nor dissipated in the resistive wall is absorbed in two high power RF loads that should be as compact as possible to minimize the total footprint of the machine. In recent years, CERN has designed, fabricated and successfully tested several loads produced by additive manufacturing. With the current design, only one load can be produced in the 3D printing machine at a time. The aim of this study is optimizing the internal cross-section of loads in order to create a stackable design to increase the number of produced parts per manufacturing cycle and thus decrease the unit price. This paper presents the new design with an optimization of the internal vacuum part of the so-called RF spiral load. In this case, RF and mechanical designs were carried out in parallel. The new cross section has showed good RF reflection reaching less than -30 dB in simulations. The final load is now ready to be manufactured and high-power tested. This new load will not only provide cost saving but also faster manufacturing for mass production.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB370

About •

paper received ※ 18 May 2021 paper accepted ※ 26 May 2021 issue date ※ 23 August 2021

Export •

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

WEPAB416

Industrialization Study of the Accelerating Structures for a 380 GeV Compact Linear Collider

3674

A. Magazinik
Tampere University, Tampere, Finland
N. Catalán Lasheras
CERN, Meyrin, Switzerland
S. Mäkinen
Tampere University of Technology, Tampere, Finland
J. Sauza-Bedolla
Lancaster University, Lancaster, United Kingdom

The LHC at CERN will continue its operation for approximately 20 years. In parallel, diverse studies are conducted for the design of a future large-scale accelerator. One of the options is the Compact Linear Collider (CLIC) who aims to provide a very high accelerating gradient (100 MV/m) achieved by using normal conducting radiofrequency (RF) cavities operating in the X-band range (12 GHz). Each accelerating structure is a challenging component involving ultra-precise machining and diffusion bonding techniques. The first stage of CLIC operates at a collision energy of 380 GeV with an accelerator length of 11 km, consisting of 21630 accelerating structures. Even though the prototypes have shown a mature and ready to build concept, the present number of qualified suppliers is limited. Therefore, an industrialization study was done through a technical survey with hi-tech companies. The aim is to evaluate current capabilities, to ensure the necessary manufacturing yield, schedule, and cost for mass production. This paper presents the results of the industrialization study for 12 GHz accelerating structures for CLIC 380 GeV, highlighting the principal challenges towards mass production.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB416

About •

paper received ※ 19 May 2021 paper accepted ※ 22 June 2021 issue date ※ 14 August 2021

Export •

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