IPAC2021 - List of Keywords (Windows)

Paper	Title	Other Keywords	Page
MOPAB336	Multipacting Analysis of Warm Linac RF Vacuum Windows	simulation, multipactoring, vacuum, GUI	1044
	G.D. Toby, Y.W. Kang, S.-H. Kim, S.W. Lee, J.S. Moss ORNL, Oak Ridge, Tennessee, USA
	Funding: * This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC05-00OR22725. Multipacting in accelerating structures is a complex phenomenon with which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures that have a higher thermal capacity and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Possible techniques for reducing and eliminating multipacting activities in these structures are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB336
About •	paper received ※ 17 May 2021 paper accepted ※ 28 May 2021 issue date ※ 29 August 2021
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TUPAB410	Finite Element Analysis and Experimental Validation of Low-Pressure Beam Windows for XCET Detectors at CERN	experiment, detector, photon, background	2487
	J. Buesa Orgaz, M. Brugger, G. Romagnoli, O. Sacristan De Frutos, F. Sanchez Galan CERN, Meyrin, Switzerland
	In the framework of the renovation and consolidation of experimental areas at CERN, a low-pressure design beam superimposed windows (250 µm Mylar and 150 µm polyethylene) for the Threshold Cherenkov counters (XCET) has been modelled and verified for its implementation. The XCET is a detector used to count the number of selected charged particles in the beam by adjusting the pressure that leads to the emission of Cherenkov photons only above certain pressure threshold. Simultaneously, the charged particles pass from a vacuum environment to the pressurized refractive gas vessel through a solid interface. Minimal material in this solid interface is therefore crucial to avoid interactions of the low-energy particles which may lead to beam intensity loss or background production. Hence, thin and low-density materials are required to mitigate multiple scattering and energy loss of the incoming particles while still allowing the needed pressures inside the counter vessel. A XCET validation methodology was conducted using Finite Element Analysis (FEA), followed by experimental validations performing burst pressure tests and using Digital Image Correlation (DIC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB410
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 24 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAB341	TiN Metalizing and Coating for Multi-Megawatt RF Vacuum Windows	electron, vacuum, multipactoring, high-voltage	4457
	M.L. Neubauer, A. Dudas, R.P. Johnson Muons, Inc, Illinois, USA
	Coatings on microwave windows and high-voltage ceramics are required to eliminate secondary electron emission (SEE), which initiates multipactoring discharge causing local heating and ceramic failures due to cracking and loss of vacuum. The region surrounding the triple junction (ceramic+metal+vacuum) is the primary source of free electrons and in microwave windows and high-voltage ceramics. This region is located at the metalizing and braze joint of the ceramic support structure making the vacuum seal. On very large microwave windows typically at low frequencies, this critical region is difficult to coat by the traditional techniques of sputter coating anti-multipactoring titanium nitride or other materials. The novel processes proposed here include a means for applying and controlling the thickness of titanium nitride both in the metallizing (controlling the source) and on the surface of the window, eliminating SEE and the multipactoring discharge.
	Poster THPAB341 [0.845 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB341
About •	paper received ※ 23 May 2021 paper accepted ※ 21 July 2021 issue date ※ 01 September 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPAB336

Multipacting Analysis of Warm Linac RF Vacuum Windows

simulation, multipactoring, vacuum, GUI

1044

G.D. Toby, Y.W. Kang, S.-H. Kim, S.W. Lee, J.S. Moss
ORNL, Oak Ridge, Tennessee, USA

Funding: * This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC05-00OR22725.
Multipacting in accelerating structures is a complex phenomenon with which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures that have a higher thermal capacity and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Possible techniques for reducing and eliminating multipacting activities in these structures are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB336

About •

paper received ※ 17 May 2021 paper accepted ※ 28 May 2021 issue date ※ 29 August 2021

Export •

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

TUPAB410

Finite Element Analysis and Experimental Validation of Low-Pressure Beam Windows for XCET Detectors at CERN

experiment, detector, photon, background

2487

J. Buesa Orgaz, M. Brugger, G. Romagnoli, O. Sacristan De Frutos, F. Sanchez Galan
CERN, Meyrin, Switzerland

In the framework of the renovation and consolidation of experimental areas at CERN, a low-pressure design beam superimposed windows (250 µm Mylar and 150 µm polyethylene) for the Threshold Cherenkov counters (XCET) has been modelled and verified for its implementation. The XCET is a detector used to count the number of selected charged particles in the beam by adjusting the pressure that leads to the emission of Cherenkov photons only above certain pressure threshold. Simultaneously, the charged particles pass from a vacuum environment to the pressurized refractive gas vessel through a solid interface. Minimal material in this solid interface is therefore crucial to avoid interactions of the low-energy particles which may lead to beam intensity loss or background production. Hence, thin and low-density materials are required to mitigate multiple scattering and energy loss of the incoming particles while still allowing the needed pressures inside the counter vessel. A XCET validation methodology was conducted using Finite Element Analysis (FEA), followed by experimental validations performing burst pressure tests and using Digital Image Correlation (DIC).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB410

About •

paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 24 August 2021

Export •

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

THPAB341

TiN Metalizing and Coating for Multi-Megawatt RF Vacuum Windows

electron, vacuum, multipactoring, high-voltage

4457

M.L. Neubauer, A. Dudas, R.P. Johnson
Muons, Inc, Illinois, USA

Coatings on microwave windows and high-voltage ceramics are required to eliminate secondary electron emission (SEE), which initiates multipactoring discharge causing local heating and ceramic failures due to cracking and loss of vacuum. The region surrounding the triple junction (ceramic+metal+vacuum) is the primary source of free electrons and in microwave windows and high-voltage ceramics. This region is located at the metalizing and braze joint of the ceramic support structure making the vacuum seal. On very large microwave windows typically at low frequencies, this critical region is difficult to coat by the traditional techniques of sputter coating anti-multipactoring titanium nitride or other materials. The novel processes proposed here include a means for applying and controlling the thickness of titanium nitride both in the metallizing (controlling the source) and on the surface of the window, eliminating SEE and the multipactoring discharge.

Poster THPAB341 [0.845 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB341

About •

paper received ※ 23 May 2021 paper accepted ※ 21 July 2021 issue date ※ 01 September 2021

Export •

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