SRF2021 - List of Authors (Kedzie, M.)

Paper	Title	Page
TUPCAV015	Performance of a Low Frequency QWR-Based SRF Gun	472
	G. Chen, M.V. Fisher, M. Kedzie, M.P. Kelly, T.B. Petersen, T. Reid ANL, Lemont, Illinois, USA X. Lu, P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. Superconducting radio-frequency (SRF) electron guns are generally considered to be an effective way of producing beams with high brightness and high repetition rates (or continuous wave). In this work, the 199.6 MHz quarter wave resonator (QWR)-based Wisconsin Free Electron Laser (WiFEL) superconducting electron gun was recently refurbished and tested at Argonne (ANL). The field performance of the e-gun was fully characterized. During this time, multipacting (MP) conditioning was performed for over 20 hours to overcome the hard MP barrier observed in the accelerating voltage range of 8 to 40 kV; the presence of multipacting is expected to operationally important for future e-guns. Here we simulated and studied the effect using CST* Microwave Studio and Particle Studio and compare with the measured data. * CST Studio Suite, version 2020, https://www.cst.com.
	Poster TUPCAV015 [4.874 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV015
About •	Received ※ 21 June 2021 — Revised ※ 20 December 2021 — Accepted ※ 22 February 2022 — Issue date ※ 23 March 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPCAV015	Refurbishment and Testing of the WiFEL E-Gun at Argonne	627
	T.B. Petersen, G. Chen, M.V. Fisher, M. Kedzie, M.P. Kelly, T. Reid ANL, Lemont, Illinois, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	We report on the refurbishment and testing of the Wisconsin Free Electron Laser (WiFEL) superconducting radiofrequency electron gun with application as an electron injector for DOE accelerators and as a possible future stand-alone tool for electron microscopy. Initial testing at ANL showed the cavity had a very low quality factor, ~10⁷, later determined to be due to contamination some-time since the initial assembly. Following ultrasonic cleaning, high-pressure water rinsing, reassembly, and cold testing, the e-gun has largely recovered with Q~10⁹ and surface electric fields ~15 MV/m. We intend that WiFEL be available as a testbed for future high brightness sources and, in particular, for testing an SRF gun photocathode loader design; an essential, and as yet, not sufficiently proven technology. We report here on many operationally important properties of a quarter-wave SRF cavity for application as an e-gun, including microphonics, pressure sensitivity, and mechanical tuning. New electromagnetic simulations show that the WiFEL cavity shape and design can be optimized in several respects.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV015
About •	Received ※ 21 June 2021 — Revised ※ 23 October 2021 — Accepted ※ 07 April 2022 — Issue date ※ 07 April 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Performance of a Low Frequency QWR-Based SRF Gun

472

G. Chen, M.V. Fisher, M. Kedzie, M.P. Kelly, T.B. Petersen, T. Reid
ANL, Lemont, Illinois, USA
X. Lu, P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
Superconducting radio-frequency (SRF) electron guns are generally considered to be an effective way of producing beams with high brightness and high repetition rates (or continuous wave). In this work, the 199.6 MHz quarter wave resonator (QWR)-based Wisconsin Free Electron Laser (WiFEL) superconducting electron gun was recently refurbished and tested at Argonne (ANL). The field performance of the e-gun was fully characterized. During this time, multipacting (MP) conditioning was performed for over 20 hours to overcome the hard MP barrier observed in the accelerating voltage range of 8 to 40 kV; the presence of multipacting is expected to operationally important for future e-guns. Here we simulated and studied the effect using CST* Microwave Studio and Particle Studio and compare with the measured data.
* CST Studio Suite, version 2020, https://www.cst.com.

Poster TUPCAV015 [4.874 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPCAV015

About •

Received ※ 21 June 2021 — Revised ※ 20 December 2021 — Accepted ※ 22 February 2022 — Issue date ※ 23 March 2022

Cite •

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

WEPCAV015

Refurbishment and Testing of the WiFEL E-Gun at Argonne

627

T.B. Petersen, G. Chen, M.V. Fisher, M. Kedzie, M.P. Kelly, T. Reid
ANL, Lemont, Illinois, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

We report on the refurbishment and testing of the Wisconsin Free Electron Laser (WiFEL) superconducting radiofrequency electron gun with application as an electron injector for DOE accelerators and as a possible future stand-alone tool for electron microscopy. Initial testing at ANL showed the cavity had a very low quality factor, ~10⁷, later determined to be due to contamination some-time since the initial assembly. Following ultrasonic cleaning, high-pressure water rinsing, reassembly, and cold testing, the e-gun has largely recovered with Q~10⁹ and surface electric fields ~15 MV/m. We intend that WiFEL be available as a testbed for future high brightness sources and, in particular, for testing an SRF gun photocathode loader design; an essential, and as yet, not sufficiently proven technology. We report here on many operationally important properties of a quarter-wave SRF cavity for application as an e-gun, including microphonics, pressure sensitivity, and mechanical tuning. New electromagnetic simulations show that the WiFEL cavity shape and design can be optimized in several respects.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPCAV015

About •

Received ※ 21 June 2021 — Revised ※ 23 October 2021 — Accepted ※ 07 April 2022 — Issue date ※ 07 April 2022

Cite •

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