LINAC2018 - List of Authors (Park, H.)

Paper	Title	Page
TUPO032	First Test Results of Superconducting Twin Axis Cavity for ERL Applications	398
	H. Park, S.U. De Silva, J.R. Delayen ODU, Norfolk, Virginia, USA A. Hutton, F. Marhauser, H. Park JLab, Newport News, Virginia, USA
	Superconducting cavities with two beam pipes had been proposed in the past for energy recovery linac applications. The relatively complex geometry of those cavities presented a serious challenge for fabrication and surface processing. Main concerns have now been overcome with the production and successful RF testing of a new elliptical twin-axis cavity proposed by Jefferson Lab and optimized by the Center for Accelerator Science at Old Dominion University in the frame of a DoE accelerator stewardship program. The cavity design provides uniform accelerating or decelerating fields for both beams. This paper describes the cavity design, fabrication experience, and the first cold RF test results and explores potential applications especially for Jefferson Lab s EIC (JLEIC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO032
About •	paper received ※ 20 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO033	Cryogenic Test Results of the SPS Prototype RF-dipole Crabbing Cavity with Higher Order Mode Couplers	402
TUOP05	use link to see paper's listing under its alternate paper code
	S.U. De Silva, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA Z. Li SLAC, Menlo Park, California, USA H. Park JLab, Newport News, Virginia, USA
	The rf-dipole crabbing cavity planned for the LHC High Luminosity Upgrade is designed to deliver a transverse kick of 3.34 MV; crabbing the proton beam in the horizontal plane. The proton beams of the LHC machine operating at 7 TeV each sets high impedance thresholds on the crabbing cavity systems. The rf-dipole crabbing cavity is designed with a two higher order mode couplers to suppress those HOMs. The first prototype of the HOM couplers are fabricated at Jefferson Lab. This paper reports the cryogenic test results of the HOM couplers with the SPS prototype rf-dipole cavity.
	Slides TUPO033 [0.859 MB]
	Poster TUPO033 [1.838 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO033
About •	paper received ※ 17 September 2018 paper accepted ※ 09 November 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO031	Investigation of the Surface Resistance of Niobium Between 325 MHz and 1300 MHz Using a Coaxial Half-wave Cavity	395
TUOP04	use link to see paper's listing under its alternate paper code
	H. Park, S.U. De Silva, J.R. Delayen ODU, Norfolk, Virginia, USA
	The Center for Accelerator Science at Old Dominion University has built a half-wave coaxial cavity () to measure the surface resistance of niobium as a function of frequency, temperature, rf field, preparation techniques, over a wide range of frequencies of interest for particle accelerators. The characteristics of the half-wave coaxial cavity provide these information on a same surface. The preliminary results showed clearly the frequency dependence of residual surface resistance (). After establishing baseline, we have conducted a study of low temperature baking effect on the surface resistance under controlled environment. This paper will describe the details of the test procedure, results and we will explore underlying physics of the phenomenon. H. Park et al., MOPB003, Proc. SRF2015, http://jacow.org/ ** H. Park et al., THPB080, Proc. SRF2017, http://jacow.org/
	Slides TUPO031 [0.966 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO031
About •	paper received ※ 17 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPO035	Determination of the Field-dependence of the Surface Resistance of Superconductors from Cavity Tests	405
TUOP12	use link to see paper's listing under its alternate paper code
	J.R. Delayen, S.U. De Silva, H. Park ODU, Norfolk, Virginia, USA
	Cryogenic tests of superconducting cavities yield an average surface resistance as a function of the peak surface magnetic field. An analytical formalism has been developed to extract the actual field dependence of the surface resistance from cavity tests and is applied to coaxial cavities and cavities of more complex geometries.
	Slides TUPO035 [0.524 MB]
	Poster TUPO035 [1.002 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO035
About •	paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

First Test Results of Superconducting Twin Axis Cavity for ERL Applications

398

H. Park, S.U. De Silva, J.R. Delayen
ODU, Norfolk, Virginia, USA
A. Hutton, F. Marhauser, H. Park
JLab, Newport News, Virginia, USA

Superconducting cavities with two beam pipes had been proposed in the past for energy recovery linac applications. The relatively complex geometry of those cavities presented a serious challenge for fabrication and surface processing. Main concerns have now been overcome with the production and successful RF testing of a new elliptical twin-axis cavity proposed by Jefferson Lab and optimized by the Center for Accelerator Science at Old Dominion University in the frame of a DoE accelerator stewardship program. The cavity design provides uniform accelerating or decelerating fields for both beams. This paper describes the cavity design, fabrication experience, and the first cold RF test results and explores potential applications especially for Jefferson Lab s EIC (JLEIC).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO032

About •

paper received ※ 20 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

Export •

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

TUPO033

Cryogenic Test Results of the SPS Prototype RF-dipole Crabbing Cavity with Higher Order Mode Couplers

402

TUOP05

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

S.U. De Silva, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
Z. Li
SLAC, Menlo Park, California, USA
H. Park
JLab, Newport News, Virginia, USA

The rf-dipole crabbing cavity planned for the LHC High Luminosity Upgrade is designed to deliver a transverse kick of 3.34 MV; crabbing the proton beam in the horizontal plane. The proton beams of the LHC machine operating at 7 TeV each sets high impedance thresholds on the crabbing cavity systems. The rf-dipole crabbing cavity is designed with a two higher order mode couplers to suppress those HOMs. The first prototype of the HOM couplers are fabricated at Jefferson Lab. This paper reports the cryogenic test results of the HOM couplers with the SPS prototype rf-dipole cavity.

Slides TUPO033 [0.859 MB]

Poster TUPO033 [1.838 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO033

About •

paper received ※ 17 September 2018 paper accepted ※ 09 November 2018 issue date ※ 18 January 2019

Export •

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

TUPO031

Investigation of the Surface Resistance of Niobium Between 325 MHz and 1300 MHz Using a Coaxial Half-wave Cavity

395

TUOP04

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

H. Park, S.U. De Silva, J.R. Delayen
ODU, Norfolk, Virginia, USA

The Center for Accelerator Science at Old Dominion University has built a half-wave coaxial cavity (*) to measure the surface resistance of niobium as a function of frequency, temperature, rf field, preparation techniques, over a wide range of frequencies of interest for particle accelerators. The characteristics of the half-wave coaxial cavity provide these information on a same surface. The preliminary results showed clearly the frequency dependence of residual surface resistance (**). After establishing baseline, we have conducted a study of low temperature baking effect on the surface resistance under controlled environment. This paper will describe the details of the test procedure, results and we will explore underlying physics of the phenomenon.
* H. Park et al., MOPB003, Proc. SRF2015, http://jacow.org/
** H. Park et al., THPB080, Proc. SRF2017, http://jacow.org/

Slides TUPO031 [0.966 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO031

About •

paper received ※ 17 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019

Export •

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

TUPO035

Determination of the Field-dependence of the Surface Resistance of Superconductors from Cavity Tests

405

TUOP12

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

J.R. Delayen, S.U. De Silva, H. Park
ODU, Norfolk, Virginia, USA

Cryogenic tests of superconducting cavities yield an average surface resistance as a function of the peak surface magnetic field. An analytical formalism has been developed to extract the actual field dependence of the surface resistance from cavity tests and is applied to coaxial cavities and cavities of more complex geometries.

Slides TUPO035 [0.524 MB]

Poster TUPO035 [1.002 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO035

About •

paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

Export •

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