NAPAC2016 - List of Authors (Dolgashev, V.A.)

Paper	Title	Page
WEPOB41	Quality Factor in High Power Tests of Cryogenic Copper Accelerating Cavities	987
SUPO04	use link to see paper's listing under its alternate paper code
	A.D. Cahill, J.B. Rosenzweig UCLA, Los Angeles, California, USA V.A. Dolgashev, M.A. Franzi, S.G. Tantawi, S.P. Weathersby SLAC, Menlo Park, California, USA
	Funding: Research made possible by DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515 Recent SLAC experiments with cryogenically cooled 11.4 GHz standing wave copper accelerating cavities have shown evidence of 250 MV/m accelerating gradients with low breakdown rates. The gradient depends on the circuit parameters of the accelerating cavity, such as the intrinsic and external quality factors (Q0, QE). In our studies we see evidence that Q₀ decreases during rf pulse at 7-70 K. This paper discusses experiments that are directed towards understanding the change of Q0 at high power.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB41
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WEPOB42	High Gradient S-Band Cryogenic Accelerating Structure for RF Breakdown Studies	991
	A.D. Cahill, A. Fukasawa, J.B. Rosenzweig UCLA, Los Angeles, California, USA G.B. Bowden, V.A. Dolgashev, S.G. Tantawi SLAC, Menlo Park, California, USA
	Funding: Work Supported by DOE/SU Contract DE-AC02-76-SF00515 and DOE SCGSR Fellowship Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdowns. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape, cavity temperature, and material. Experimental and theoretical study of the effects of these parameters on the breakdown physics is ongoing at SLAC. As of now, most of the data has been obtained at 11.4 GHz. We are extending this research to S-band. We have designed a single cell accelerating structure, based on the extensively tested X-band cavities. The setup uses matched TM01 mode launcher to feed rf power into the test cavity. Our ongoing study of the physics of rf breakdown in cryogenically X-band accelerating cavities shows improved breakdown performance. Therefore, this S-band experiment is designed to cool the cavity to cryogenic temperatures. We use operating frequencies near 2.856 GHz. We present the rf design and discuss the experimental setup.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB42
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

WEPOB41

Quality Factor in High Power Tests of Cryogenic Copper Accelerating Cavities

987

SUPO04

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

A.D. Cahill, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
V.A. Dolgashev, M.A. Franzi, S.G. Tantawi, S.P. Weathersby
SLAC, Menlo Park, California, USA

Funding: Research made possible by DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515
Recent SLAC experiments with cryogenically cooled 11.4 GHz standing wave copper accelerating cavities have shown evidence of 250 MV/m accelerating gradients with low breakdown rates. The gradient depends on the circuit parameters of the accelerating cavity, such as the intrinsic and external quality factors (Q0, QE). In our studies we see evidence that Q₀ decreases during rf pulse at 7-70 K. This paper discusses experiments that are directed towards understanding the change of Q0 at high power.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB41

Export •

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

WEPOB42

High Gradient S-Band Cryogenic Accelerating Structure for RF Breakdown Studies

991

A.D. Cahill, A. Fukasawa, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
G.B. Bowden, V.A. Dolgashev, S.G. Tantawi
SLAC, Menlo Park, California, USA

Funding: Work Supported by DOE/SU Contract DE-AC02-76-SF00515 and DOE SCGSR Fellowship
Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdowns. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape, cavity temperature, and material. Experimental and theoretical study of the effects of these parameters on the breakdown physics is ongoing at SLAC. As of now, most of the data has been obtained at 11.4 GHz. We are extending this research to S-band. We have designed a single cell accelerating structure, based on the extensively tested X-band cavities. The setup uses matched TM01 mode launcher to feed rf power into the test cavity. Our ongoing study of the physics of rf breakdown in cryogenically X-band accelerating cavities shows improved breakdown performance. Therefore, this S-band experiment is designed to cool the cavity to cryogenic temperatures. We use operating frequencies near 2.856 GHz. We present the rf design and discuss the experimental setup.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB42

Export •

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