IPAC2022 - List of Authors (Parajuli, I.P.)

Paper	Title	Page
TUPOTK044	Preliminary Results of a Magnetic and Temperature Map System for 3 GHz Superconducting Radio Frequency Cavities	1315
	I.P. Parajuli, G. Ciovati, J.R. Delayen, A.V. Gurevich, B.D. Khanal ODU, Norfolk, Virginia, USA G. Ciovati, J.R. Delayen JLab, Newport News, Virginia, USA
	Funding: Work supported by NSF Grant 100614-010. Jlab work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Superconducting radio frequency (SRF) cavities are fundamental building blocks of modern particle accelerators. A surface resistance in the tens of nanoOhm range is achieved when cooling these cavities to liquid helium temperature, ~2 - 4 K. One of the leading sources of residual losses in SRF cavities is trapped magnetic flux. Flux trapping mechanism depends on different surface preparations and cool-down conditions. We have designed, developed and commissioned a combined magnetic and temperature mapping system using anisotropic magneto-resistance sensors and carbon resistors, respectively, to study the flux trap mechanism in 3 GHz single-cell niobium cavities. In this contribution, we will describe the experimental apparatus and present preliminary test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK044
About •	Received ※ 02 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 25 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOTK045	Magnetic Field Mapping of 1.3 GHz Superconducting Radio Frequency Niobium Cavities	1319
SUSPMF114	use link to see paper's listing under its alternate paper code
	I.P. Parajuli, G. Ciovati, J.R. Delayen, A.V. Gurevich ODU, Norfolk, Virginia, USA G. Ciovati, J.R. Delayen JLab, Newport News, Virginia, USA
	Funding: Work supported by NSF Grant 100614-010. Jlab work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Niobium is the material of choice to build superconducting radio frequency (SRF) cavities, which are fundamental building blocks of modern particle accelerators. These cavities require a cryogenic cool-down to ~2 - 4 K for optimum performance minimizing RF losses on the inner cavity surface. However, temperature-independent residual losses in SRF cavities cannot be prevented entirely. One of the significant contributor to residual losses is trapped magnetic flux. The flux trapping mechanism depends on different factors, such as surface preparations and cool-down conditions. We have developed a diagnostic magnetic field scanning system (MFSS) using Hall probes and anisotropic magneto-resistance sensors to study the spatial distribution of trapped flux in 1.3 GHz single-cell cavities. The first result from this newly commissioned system revealed that the trapped flux on the cavity surface might redistribute with increasing RF power. The MFSS was also able to capture significant magnetic field enhancement at specific cavity locations after a quench.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK045
About •	Received ※ 02 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 27 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Preliminary Results of a Magnetic and Temperature Map System for 3 GHz Superconducting Radio Frequency Cavities

1315

I.P. Parajuli, G. Ciovati, J.R. Delayen, A.V. Gurevich, B.D. Khanal
ODU, Norfolk, Virginia, USA
G. Ciovati, J.R. Delayen
JLab, Newport News, Virginia, USA

Funding: Work supported by NSF Grant 100614-010. Jlab work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Superconducting radio frequency (SRF) cavities are fundamental building blocks of modern particle accelerators. A surface resistance in the tens of nanoOhm range is achieved when cooling these cavities to liquid helium temperature, ~2 - 4 K. One of the leading sources of residual losses in SRF cavities is trapped magnetic flux. Flux trapping mechanism depends on different surface preparations and cool-down conditions. We have designed, developed and commissioned a combined magnetic and temperature mapping system using anisotropic magneto-resistance sensors and carbon resistors, respectively, to study the flux trap mechanism in 3 GHz single-cell niobium cavities. In this contribution, we will describe the experimental apparatus and present preliminary test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK044

About •

Received ※ 02 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 25 June 2022

Cite •

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

TUPOTK045

Magnetic Field Mapping of 1.3 GHz Superconducting Radio Frequency Niobium Cavities

1319

SUSPMF114

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

I.P. Parajuli, G. Ciovati, J.R. Delayen, A.V. Gurevich
ODU, Norfolk, Virginia, USA
G. Ciovati, J.R. Delayen
JLab, Newport News, Virginia, USA

Funding: Work supported by NSF Grant 100614-010. Jlab work is supported by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Niobium is the material of choice to build superconducting radio frequency (SRF) cavities, which are fundamental building blocks of modern particle accelerators. These cavities require a cryogenic cool-down to ~2 - 4 K for optimum performance minimizing RF losses on the inner cavity surface. However, temperature-independent residual losses in SRF cavities cannot be prevented entirely. One of the significant contributor to residual losses is trapped magnetic flux. The flux trapping mechanism depends on different factors, such as surface preparations and cool-down conditions. We have developed a diagnostic magnetic field scanning system (MFSS) using Hall probes and anisotropic magneto-resistance sensors to study the spatial distribution of trapped flux in 1.3 GHz single-cell cavities. The first result from this newly commissioned system revealed that the trapped flux on the cavity surface might redistribute with increasing RF power. The MFSS was also able to capture significant magnetic field enhancement at specific cavity locations after a quench.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK045

About •

Received ※ 02 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 27 June 2022

Cite •

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