NAPAC2022 - List of Keywords (power-supply)

Paper	Title	Other Keywords	Page
MOPA22	Study on Electropolishing Conditions for 650 MHz Niobium SRF Cavity	cavity, cathode, SRF, niobium	97
	V. Chouhan, D.J. Bice, F. Furuta, M. Martinello, M.K. Ng, H. Park, T.J. Ring, G. Wu Fermilab, Batavia, Illinois, USA B.M. Guilfoyle, M.P. Kelly, T. Reid ANL, Lemont, Illinois, USA
	The PIP II linear accelerator includes different types of niobium SRF cavities including 650 MHz elliptical low (0.61) and high (0.92) beta cavities. The elliptical cavity surface is processed with the electropolishing method. The elliptical cavities especially the low-beta 650 MHz cavities showed a rough equator surface after the EP was performed with the standard EP conditions. This work was focused to study the effect of different EP parameters, including cathode surface area, temperature and voltage, and optimize them to improve the cavity surface.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA22
About •	Received ※ 02 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 03 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPA43	Dee Voltage Regulator for the 88-Inch Cyclotron	cyclotron, feedback, detector, controls	147
	M. Kireeff, P. Bloemhard, T. Hassan, L. Phair LBNL, Berkeley, California, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract No. DE-AC02-05CH11231 A new broadband Dee voltage regulator was designed and built for the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The previous regulator was obsolete, consequently, it was difficult to troubleshoot and repair. Additionally, during operation, it displayed problems of distortion and stability at certain frequencies. The new regulator uses off-the-shelf components that can detect and disable the RF during sparking events, protecting the RF driver system. Furthermore, it improves the tuning of the cyclotron and allows consistency in operation.
	Poster MOPA43 [1.032 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA43
About •	Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 16 August 2022 — Issue date ※ 09 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPA61	Modular Solid-State Switching and Arc Suppression for Vacuum Tube Bias Circuits	high-voltage, vacuum, pulsed-power, operation	179
	E.L. Atkinson, T.J. Houlahan, B.E. Jurczyk, R.A. Stubbers Starfire Industries LLC, Champaign, USA
	In this work, we present operational and performance data for a solid-state switching circuit that delivers pulsed power at up to 12 kV and 100 A. This circuit, which is comprised of a series configuration of IGBT-based subcircuits, is suitable for driving the high-power vacuum-tube amplifiers that are typically used in RF accelerator systems. Each subcircuit can switch up to 3 kV, and the subcircuits can be stacked in series to extend the overall voltage capabilities of the switch. The circuit is designed to prevent overvoltaging any single transistor during switching transients or faults, regardless of the number of series subcircuits. Further, the circuit also includes the capability for rapid arc detection and suppression. Testing has shown effective switching at up to 100 A at 12 kV and for pulse repetition frequencies and durations in the range of 1-200 Hz and 10-50 µs, respectively. Additionally, the arc suppression circuitry has been shown to reliably limit arcs at 8-12 kV with a quench time of <1 µs and with a total energy of <0.2 J, minimizing the grid erosion in the vacuum-tube during an arc.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA61
About •	Received ※ 01 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 20 August 2022 — Issue date ※ 10 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA29	Machine Learning for Predicting Power Supply Trips in Storage Rings	storage-ring, network, quadrupole, sextupole	413
	I. Lobach, M. Borland, G.I. Fystro, A. Sannibale, Y. Sun ANL, Lemont, Illinois, USA A. Diaw, J.P. Edelen RadiaSoft LLC, Boulder, Colorado, USA
	Funding: The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. In the Advanced Photon Source (APS) storage ring at Argonne National Lab, trips in the magnet power supplies (PSs) lead to a complete electron beam loss a few times a year. This results in unexpected interruptions of the users’ experiments. In this contribution, we investigate the historical data for the last two decades to find precursors for the PS trips that could provide an advance notice for future trips and allow some preventive action by the ring operator or by the PS maintenance team. Various unsupervised anomaly detection models can be trained on the vast amounts of available reference data from the beamtime periods that ended with an intentional beam dump. We find that such models can sometimes detect trip precursors in PS currents, voltages, and in the temperatures of magnets, capacitors and transistors (components of PSs).
	Poster TUPA29 [2.116 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA29
About •	Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 18 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPA30	Development of a Compact 2D Carbon Beam Scanner for Cancer Therapy	proton, simulation, magnet-design, radiation	417
	B. Mustapha, A. Barcikowski, J.A. Nolen ANL, Lemont, Illinois, USA V.P. Derenchuk, P. Osucha ProNova Solutions, Knoxville, USA N. Tsoupas BNL, Upton, New York, USA
	Funding: This work was supported by the U.S. Department of Energy, under Contract No. DE-AC02-06CH11357. This research was support through the DOE’s Accelerator Stewardship program. A novel trapezoidal coil 2D carbon beam scanner has been designed, and a prototype has been successfully developed and tested. The field performance of the magnet has been characterized and it is in excellent agreement with the simulations. A better than 1% field uniformity in both planes has been achieved within the useful aperture of the magnet. This represents a significant improvement over the prior art of the elephant-ear scanner design. A comparison of the two designs and the results from the new trapezoidal-coil design will be presented and discussed. Higher power and online beam testing are planned in the near future.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA30
About •	Received ※ 25 July 2022 — Revised ※ 14 August 2022 — Accepted ※ 15 August 2022 — Issue date ※ 25 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZD3	Magnetron R&D Progress for High Efficiency CW RF Sources of Industrial Accelerators	injection, controls, feedback, experiment	597
	H. Wang, K. Jordan, R.M. Nelson, S.A. Overstreet, R.A. Rimmer JLab, Newport News, Virginia, USA J.N. Blum VCU, Richmond, Virginia, USA B.R.L. Coriton, C.P. Moeller, K.A. Thackston GA, San Diego, California, USA J.L. Vega The College of William and Mary, Williamsburg, Virginia, USA G. Ziemyte UKY, Kentucky, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177, and DOE OS/HEP Accelerator Stewardship award 2019-2022. After the demonstration of using high efficiency magnetron power to combine and aim to drive a radio frequency accelerator at 2450MHz in CW mode [1], we have used trim coils adding to a water-cooled magnetron and three amplitude modulation methods in an open-loop control to further suppress the 120Hz side-band noise to -46.7dBc level. We have also successfully demonstrated the phase-locking to an industrial grade cooking magnetron transmitter at 915MHz with a 75kW CW power delivered to a water load by using a -26.6dBc injection signal. The sideband noise at 360Hz from the 3-Phase SCRs DC power supply can be reduced to -16.2dBc level. Their power combing scheme and higher power application to industrial accelerators are foreseeing. [1] H. Wang, et al, Magnetron R&D for High Efficiency CW RF Sources for Industrial Accelerators, TUPAB348, 12th Int. Particle Acc. Conf. IPAC2021, Campinas, SP, Brazil.
	Slides WEZD3 [3.074 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEZD3
About •	Received ※ 18 July 2022 — Revised ※ 25 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 11 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPA16	A 500 kV Inverted Geometry Feedthrough for a High Voltage DC Electron Gun	gun, high-voltage, electron, cathode	651
	C. Hernandez-Garcia, D.B. Bullard, J.M. Grames, G.G. Palacios Serrano, M. Poelker JLab, Newport News, Virginia, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177 and Office of Science Funding Opportunity LAB 20-2310 award PAMS-254442. The Continuous Electron Beam Accelerator Facility injector at Jefferson Lab (JLab) utilizes an inverted-geometry ceramic insulator photogun operating at 130 kV direct current to generate spin-polarized electron beams for high-energy nuclear physics experiments. A second photogun delivers 180 keV beam for commissioning a SRF booster in a testbed accelerator, and a larger version delivers 300 keV magnetized beam in a test stand beam line. This contribution reports on the development of an unprecedented inverted-insulator with cable connector for reliably applying 500 kV DC to a future polarized beam photogun, to be designed for operating at 350 kV without field emission. Such a photogun design could then be used for generating a polarized electron beam to drive a spin-polarized positron source as a demonstrator for high energy nuclear physics at JLab. There are no commercial cable connectors that fit the large inverted insulators required for that voltage range. Our proposed concept is based on a modified epoxy receptacle with intervening SF6 layer and a test electrode in a vacuum vessel.
	Poster WEPA16 [6.217 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA16
About •	Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 09 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPA22

Study on Electropolishing Conditions for 650 MHz Niobium SRF Cavity

cavity, cathode, SRF, niobium

97

V. Chouhan, D.J. Bice, F. Furuta, M. Martinello, M.K. Ng, H. Park, T.J. Ring, G. Wu
Fermilab, Batavia, Illinois, USA
B.M. Guilfoyle, M.P. Kelly, T. Reid
ANL, Lemont, Illinois, USA

The PIP II linear accelerator includes different types of niobium SRF cavities including 650 MHz elliptical low (0.61) and high (0.92) beta cavities. The elliptical cavity surface is processed with the electropolishing method. The elliptical cavities especially the low-beta 650 MHz cavities showed a rough equator surface after the EP was performed with the standard EP conditions. This work was focused to study the effect of different EP parameters, including cathode surface area, temperature and voltage, and optimize them to improve the cavity surface.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA22

About •

Received ※ 02 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 03 September 2022

Cite •

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

MOPA43

Dee Voltage Regulator for the 88-Inch Cyclotron

cyclotron, feedback, detector, controls

147

M. Kireeff, P. Bloemhard, T. Hassan, L. Phair
LBNL, Berkeley, California, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract No. DE-AC02-05CH11231
A new broadband Dee voltage regulator was designed and built for the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The previous regulator was obsolete, consequently, it was difficult to troubleshoot and repair. Additionally, during operation, it displayed problems of distortion and stability at certain frequencies. The new regulator uses off-the-shelf components that can detect and disable the RF during sparking events, protecting the RF driver system. Furthermore, it improves the tuning of the cyclotron and allows consistency in operation.

Poster MOPA43 [1.032 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA43

About •

Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 16 August 2022 — Issue date ※ 09 September 2022

Cite •

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

MOPA61

Modular Solid-State Switching and Arc Suppression for Vacuum Tube Bias Circuits

high-voltage, vacuum, pulsed-power, operation

179

E.L. Atkinson, T.J. Houlahan, B.E. Jurczyk, R.A. Stubbers
Starfire Industries LLC, Champaign, USA

In this work, we present operational and performance data for a solid-state switching circuit that delivers pulsed power at up to 12 kV and 100 A. This circuit, which is comprised of a series configuration of IGBT-based subcircuits, is suitable for driving the high-power vacuum-tube amplifiers that are typically used in RF accelerator systems. Each subcircuit can switch up to 3 kV, and the subcircuits can be stacked in series to extend the overall voltage capabilities of the switch. The circuit is designed to prevent overvoltaging any single transistor during switching transients or faults, regardless of the number of series subcircuits. Further, the circuit also includes the capability for rapid arc detection and suppression. Testing has shown effective switching at up to 100 A at 12 kV and for pulse repetition frequencies and durations in the range of 1-200 Hz and 10-50 µs, respectively. Additionally, the arc suppression circuitry has been shown to reliably limit arcs at 8-12 kV with a quench time of <1 µs and with a total energy of <0.2 J, minimizing the grid erosion in the vacuum-tube during an arc.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA61

About •

Received ※ 01 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 20 August 2022 — Issue date ※ 10 September 2022

Cite •

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

TUPA29

Machine Learning for Predicting Power Supply Trips in Storage Rings

storage-ring, network, quadrupole, sextupole

413

I. Lobach, M. Borland, G.I. Fystro, A. Sannibale, Y. Sun
ANL, Lemont, Illinois, USA
A. Diaw, J.P. Edelen
RadiaSoft LLC, Boulder, Colorado, USA

Funding: The work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
In the Advanced Photon Source (APS) storage ring at Argonne National Lab, trips in the magnet power supplies (PSs) lead to a complete electron beam loss a few times a year. This results in unexpected interruptions of the users’ experiments. In this contribution, we investigate the historical data for the last two decades to find precursors for the PS trips that could provide an advance notice for future trips and allow some preventive action by the ring operator or by the PS maintenance team. Various unsupervised anomaly detection models can be trained on the vast amounts of available reference data from the beamtime periods that ended with an intentional beam dump. We find that such models can sometimes detect trip precursors in PS currents, voltages, and in the temperatures of magnets, capacitors and transistors (components of PSs).

Poster TUPA29 [2.116 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA29

About •

Received ※ 03 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 10 August 2022 — Issue date ※ 18 August 2022

Cite •

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

TUPA30

Development of a Compact 2D Carbon Beam Scanner for Cancer Therapy

proton, simulation, magnet-design, radiation

417

B. Mustapha, A. Barcikowski, J.A. Nolen
ANL, Lemont, Illinois, USA
V.P. Derenchuk, P. Osucha
ProNova Solutions, Knoxville, USA
N. Tsoupas
BNL, Upton, New York, USA

Funding: This work was supported by the U.S. Department of Energy, under Contract No. DE-AC02-06CH11357. This research was support through the DOE’s Accelerator Stewardship program.
A novel trapezoidal coil 2D carbon beam scanner has been designed, and a prototype has been successfully developed and tested. The field performance of the magnet has been characterized and it is in excellent agreement with the simulations. A better than 1% field uniformity in both planes has been achieved within the useful aperture of the magnet. This represents a significant improvement over the prior art of the elephant-ear scanner design. A comparison of the two designs and the results from the new trapezoidal-coil design will be presented and discussed. Higher power and online beam testing are planned in the near future.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUPA30

About •

Received ※ 25 July 2022 — Revised ※ 14 August 2022 — Accepted ※ 15 August 2022 — Issue date ※ 25 August 2022

Cite •

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

WEZD3

Magnetron R&D Progress for High Efficiency CW RF Sources of Industrial Accelerators

injection, controls, feedback, experiment

597

H. Wang, K. Jordan, R.M. Nelson, S.A. Overstreet, R.A. Rimmer
JLab, Newport News, Virginia, USA
J.N. Blum
VCU, Richmond, Virginia, USA
B.R.L. Coriton, C.P. Moeller, K.A. Thackston
GA, San Diego, California, USA
J.L. Vega
The College of William and Mary, Williamsburg, Virginia, USA
G. Ziemyte
UKY, Kentucky, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177, and DOE OS/HEP Accelerator Stewardship award 2019-2022.
After the demonstration of using high efficiency magnetron power to combine and aim to drive a radio frequency accelerator at 2450MHz in CW mode [1], we have used trim coils adding to a water-cooled magnetron and three amplitude modulation methods in an open-loop control to further suppress the 120Hz side-band noise to -46.7dBc level. We have also successfully demonstrated the phase-locking to an industrial grade cooking magnetron transmitter at 915MHz with a 75kW CW power delivered to a water load by using a -26.6dBc injection signal. The sideband noise at 360Hz from the 3-Phase SCRs DC power supply can be reduced to -16.2dBc level. Their power combing scheme and higher power application to industrial accelerators are foreseeing.
[1] H. Wang, et al, Magnetron R&D for High Efficiency CW RF Sources for Industrial Accelerators, TUPAB348, 12th Int. Particle Acc. Conf. IPAC2021, Campinas, SP, Brazil.

Slides WEZD3 [3.074 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEZD3

About •

Received ※ 18 July 2022 — Revised ※ 25 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 11 August 2022

Cite •

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

WEPA16

A 500 kV Inverted Geometry Feedthrough for a High Voltage DC Electron Gun

gun, high-voltage, electron, cathode

651

C. Hernandez-Garcia, D.B. Bullard, J.M. Grames, G.G. Palacios Serrano, M. Poelker
JLab, Newport News, Virginia, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177 and Office of Science Funding Opportunity LAB 20-2310 award PAMS-254442.
The Continuous Electron Beam Accelerator Facility injector at Jefferson Lab (JLab) utilizes an inverted-geometry ceramic insulator photogun operating at 130 kV direct current to generate spin-polarized electron beams for high-energy nuclear physics experiments. A second photogun delivers 180 keV beam for commissioning a SRF booster in a testbed accelerator, and a larger version delivers 300 keV magnetized beam in a test stand beam line. This contribution reports on the development of an unprecedented inverted-insulator with cable connector for reliably applying 500 kV DC to a future polarized beam photogun, to be designed for operating at 350 kV without field emission. Such a photogun design could then be used for generating a polarized electron beam to drive a spin-polarized positron source as a demonstrator for high energy nuclear physics at JLab. There are no commercial cable connectors that fit the large inverted insulators required for that voltage range. Our proposed concept is based on a modified epoxy receptacle with intervening SF6 layer and a test electrode in a vacuum vessel.

Poster WEPA16 [6.217 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA16

About •

Received ※ 03 August 2022 — Revised ※ 05 August 2022 — Accepted ※ 07 August 2022 — Issue date ※ 09 October 2022

Cite •

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