NAPAC2016 - List of Authors (Schappert, W.)

Paper

Title

Page

A Novel Technique of Power Control in Magnetron Transmitters for Intense Accelerators

271

G.M. Kazakevich, R.P. Johnson, M.L. Neubauer
Muons, Inc, Illinois, USA
V.A. Lebedev, W. Schappert, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

A novel concept of a high-power magnetron transmitter allowing dynamic phase and power control at the frequency of locking signal is proposed. The transmitter compensating parasitic phase and amplitude modulations inherent in Superconducting RF (SRF) cavities within closed feedback loops is intended for powering of the intensity-frontier superconducting accelerators. The concept uses magnetrons driven by a sufficient resonant (injection-locking) signal and fed by the voltage which can be below the threshold of self-excitation. This provides an extended range of power control in a single magnetron at highest efficiency minimizing the cost of RF power unit and the operation cost. Proof-of-principle of the proposed concept demonstrated in pulsed and CW regimes with 2.45 GHz, 1kW magnetrons is discussed here. A conceptual scheme of the high-power transmitter allowing the dynamic wideband phase and mid-frequency power controls is presented and discussed.

Slides TUA2CO03 [0.714 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA2CO03

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FRA2CO04

Status of the SRF Cavities Resonance Control R&D Work at FNAL

Y.M. Pischalnikov, J.P. Holzbauer, W. Schappert
Fermilab, Batavia, Illinois, USA

There are several new machines under construction or development at this moment. Some machines, (LCLS II and PIP II ) will operate with the relatively low beam currents and high cavity quality factors. SRF cavities for these projects will be operated with small RF bandwidths, meaning that they will be highly sensitive to microphonics and Lorentz force detuning. Other future projects such as ESS will be operate with SRF cavities tuned for larger RF bandwidth but will still have significant Lorentz Force Detuning. Work is ongoing at FNAL to develop active resonance stabilization techniques using fast piezoelectric tuners in support of PIP-II and LCLS II. These techniques as well as testing and development results using a prototype, dressed low-beta single-spoke cavity and 9-cell elliptical cavities will be presented along with an outlook for future efforts.

Slides FRA2CO04 [3.544 MB]

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Paper	Title	Page
TUA2CO03	A Novel Technique of Power Control in Magnetron Transmitters for Intense Accelerators	271
	G.M. Kazakevich, R.P. Johnson, M.L. Neubauer Muons, Inc, Illinois, USA V.A. Lebedev, W. Schappert, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	A novel concept of a high-power magnetron transmitter allowing dynamic phase and power control at the frequency of locking signal is proposed. The transmitter compensating parasitic phase and amplitude modulations inherent in Superconducting RF (SRF) cavities within closed feedback loops is intended for powering of the intensity-frontier superconducting accelerators. The concept uses magnetrons driven by a sufficient resonant (injection-locking) signal and fed by the voltage which can be below the threshold of self-excitation. This provides an extended range of power control in a single magnetron at highest efficiency minimizing the cost of RF power unit and the operation cost. Proof-of-principle of the proposed concept demonstrated in pulsed and CW regimes with 2.45 GHz, 1kW magnetrons is discussed here. A conceptual scheme of the high-power transmitter allowing the dynamic wideband phase and mid-frequency power controls is presented and discussed.
	Slides TUA2CO03 [0.714 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA2CO03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRA2CO04	Status of the SRF Cavities Resonance Control R&D Work at FNAL
	Y.M. Pischalnikov, J.P. Holzbauer, W. Schappert Fermilab, Batavia, Illinois, USA
	There are several new machines under construction or development at this moment. Some machines, (LCLS II and PIP II ) will operate with the relatively low beam currents and high cavity quality factors. SRF cavities for these projects will be operated with small RF bandwidths, meaning that they will be highly sensitive to microphonics and Lorentz force detuning. Other future projects such as ESS will be operate with SRF cavities tuned for larger RF bandwidth but will still have significant Lorentz Force Detuning. Work is ongoing at FNAL to develop active resonance stabilization techniques using fast piezoelectric tuners in support of PIP-II and LCLS II. These techniques as well as testing and development results using a prototype, dressed low-beta single-spoke cavity and 9-cell elliptical cavities will be presented along with an outlook for future efforts.
	Slides FRA2CO04 [3.544 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)