IPAC2019 - List of Keywords (RF-structure)

Paper	Title	Other Keywords	Page
WEPRB075	Optimizing Room Temperature RF Structures for Accelerator Driven System Operations	vacuum, cavity, operation, DTL	2993
	D.L. Brown, M.T. Crofford ORNL, Oak Ridge, Tennessee, USA C.C. Peters ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. Minimizing beam trip rates is one of the key operational goals at the Spallation Neutron Source (SNS). Trip rates are closely monitored, and real-time statistics are kept during beam operations for immediate analysis. Beam trips are automatically binned by the length of the trip along with the cause for each trip. The shortest beam trips occur with the highest frequency and those trip rates are dominated by the room temperature RF structures. There can be many causes for the RF structure malfunctions, but one area that has had a major impact on trip rates is improvement in how RF processing is done on structures after extended maintenance periods. Details about the improvement in RF conditioning will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB075
About •	paper received ※ 13 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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WEPRB113	Toolbox for Optimization of RF Efficiency for Linacs	linac, klystron, booster, software	3074
	J. Ögren, A. Latina, D. Schulte CERN, Meyrin, Switzerland
	We present a toolbox for optimizing the rf efficiency for linacs and as an example we use it to re-optimize the Compact Linear Collider booster linac. We have implemented a numerical model of a SLED-type pulse compressor that can generate a single or a double pulse. Together with the CERN CLICopti library, an RF structure parameter estimator, we created the toolbox which enables thorough optimizations of linacs in terms of RF efficiency, beam stability, and cost simultaneously, via a simple and concise Octave script. This toolbox was created for the optimization of X-band-based linacs, however it can also be used at lower frequencies, e.g. in the S- and in the C- bands of frequencies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB113
About •	paper received ※ 06 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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THPGW078	Prototyping of Brazed mm-Wave Accelerating Structures	cavity, resonance, simulation, GUI	3764
	M.A.K. Othman, B.J. Angier, A.A. Haase, E.A. Nanni, M.R. Roux, A.V. Sy SLAC, Menlo Park, California, USA
	Funding: This work was supported by Department of Energy contract DE-AC02-76SF00515. This work was also supported by NSF grants PHY-1734015. Advanced fabrication and prototyping of metallic RF structures play a fundamental role in advancing accelerator technologies particularly at mm-wave and THz frequencies. With the scaling of the RF structure up to these frequencies, conventional fabrication techniques do not achieve the required accuracy and tolerances. Improved manufacturing techniques including diffusion bonding, brazing or clamping split-block geometries produce high quality structures when successfully implemented. However, in most schemes the resulting gap and irregularities at the iris result in a local field enhancement which is not desirable for high-gradient operation. Development of advanced split-block braze technique for THz accelerators was required for high quality miniature accelerators. A new braze technique was developed for W-band structures to control the flow of braze alloy, enabling fabrication of the first high-gradient brazed structures at mm-wave frequencies. This fabrication process has the potential to overcome consistent fabrication defects around the cell iris. Thin spacers were used to set the final gap between blocks during the braze process; while braze foil thickness is varied with minimal impact on the resulting frequency. To demonstrate the robustness of this technique, testing after the various manufacturing steps was done to monitor and track frequency change throughout the process. This technique is further pushed to produce G-band RF structures, operating at 300 GHz.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW078
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)

Paper

Title

Other Keywords

Page

WEPRB075

Optimizing Room Temperature RF Structures for Accelerator Driven System Operations

vacuum, cavity, operation, DTL

2993

D.L. Brown, M.T. Crofford
ORNL, Oak Ridge, Tennessee, USA
C.C. Peters
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.
Minimizing beam trip rates is one of the key operational goals at the Spallation Neutron Source (SNS). Trip rates are closely monitored, and real-time statistics are kept during beam operations for immediate analysis. Beam trips are automatically binned by the length of the trip along with the cause for each trip. The shortest beam trips occur with the highest frequency and those trip rates are dominated by the room temperature RF structures. There can be many causes for the RF structure malfunctions, but one area that has had a major impact on trip rates is improvement in how RF processing is done on structures after extended maintenance periods. Details about the improvement in RF conditioning will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB075

About •

paper received ※ 13 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)

WEPRB113

Toolbox for Optimization of RF Efficiency for Linacs

linac, klystron, booster, software

3074

J. Ögren, A. Latina, D. Schulte
CERN, Meyrin, Switzerland

We present a toolbox for optimizing the rf efficiency for linacs and as an example we use it to re-optimize the Compact Linear Collider booster linac. We have implemented a numerical model of a SLED-type pulse compressor that can generate a single or a double pulse. Together with the CERN CLICopti library, an RF structure parameter estimator, we created the toolbox which enables thorough optimizations of linacs in terms of RF efficiency, beam stability, and cost simultaneously, via a simple and concise Octave script. This toolbox was created for the optimization of X-band-based linacs, however it can also be used at lower frequencies, e.g. in the S- and in the C- bands of frequencies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB113

About •

paper received ※ 06 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)

THPGW078

Prototyping of Brazed mm-Wave Accelerating Structures

cavity, resonance, simulation, GUI

3764

M.A.K. Othman, B.J. Angier, A.A. Haase, E.A. Nanni, M.R. Roux, A.V. Sy
SLAC, Menlo Park, California, USA

Funding: This work was supported by Department of Energy contract DE-AC02-76SF00515. This work was also supported by NSF grants PHY-1734015.
Advanced fabrication and prototyping of metallic RF structures play a fundamental role in advancing accelerator technologies particularly at mm-wave and THz frequencies. With the scaling of the RF structure up to these frequencies, conventional fabrication techniques do not achieve the required accuracy and tolerances. Improved manufacturing techniques including diffusion bonding, brazing or clamping split-block geometries produce high quality structures when successfully implemented. However, in most schemes the resulting gap and irregularities at the iris result in a local field enhancement which is not desirable for high-gradient operation. Development of advanced split-block braze technique for THz accelerators was required for high quality miniature accelerators. A new braze technique was developed for W-band structures to control the flow of braze alloy, enabling fabrication of the first high-gradient brazed structures at mm-wave frequencies. This fabrication process has the potential to overcome consistent fabrication defects around the cell iris. Thin spacers were used to set the final gap between blocks during the braze process; while braze foil thickness is varied with minimal impact on the resulting frequency. To demonstrate the robustness of this technique, testing after the various manufacturing steps was done to monitor and track frequency change throughout the process. This technique is further pushed to produce G-band RF structures, operating at 300 GHz.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW078

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)