NAPAC2016 - List of Keywords (LLRF)

Paper	Title	Other Keywords	Page
TUPOA12	An Updated LLRF Control System for the TLS Linac	ion, controls, linac, EPICS	308
	C.Y. Wu, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Liao NSRRC, Hsinchu, Taiwan
	The amplitude and phase of the RF field at the linear accelerator (LINAC) decides the beam quality. To study and to improve the performance of the LINAC system for Taiwan Light Source (TLS), a new design of a low-level radio-frequency (LLRF) control system was developed and set up for the TLS LINAC. The main components of the LLRF control system are an I/Q modulator, an Ethernet-based arbitrary waveform generator, a digital oscilloscope and an I/Q demodulator; these are essential parts of the LLRF feed-forward control. This paper presents the efforts to improve the LLRF control system. The feasibility of the RF feed-forward control will be studied at the linear accelerator of TLS.
	Poster TUPOA12 [1.425 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA12
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TUPOA18	Low Level RF Control for the PIP-II Injector Test RFQ	ion, rfq, controls, cavity	323
	J.P. Edelen, B.E. Chase, E. Cullerton, J. Einstein, P. Varghese Fermilab, Batavia, Illinois, USA
	The PIP-II injector test radio frequency quadrupole (RFQ) arrived at Fermilab in the fall of 2015. The RFQ is a 162.5MHz H⁻ accelerator with a nominal drive power of 100kW, which produces a bunched H⁻ beam at 2.1MeV. In this paper we discuss commissioning, operational performance, and improvements to the low level RF (LLRF) control system for the RFQ. We begin by describing the general system configuration and initial simulation results. We will then highlight temperature related issues in the high power RF system, which necessitate active control over the phase balance of the two amplifiers. Finally we demonstrate performance of the RF feedback and feed-forward compensation needed to meet specification during a 20-microsecond beam pulse.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA18
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TUPOA40	Low Noise Digitizer Design for LCLS-II LLRF	ion, FPGA, cavity, hardware	364
	G. Huang, L.R. Doolittle, Y.L. Xu, J. Yang LBNL, Berkeley, California, USA Y.L. Xu, J. Yang TUB, Beijing, People's Republic of China
	Modern accelerators use a digital low level RF controller to stabilize the fields in accelerator cavities. The noise in the receiver chain and analog to digital conversion (ADC) for the cavity probe signal is critically important. Within the closed-loop bandwidth, it will eventually become part of the field noise seen by the beam in the accelerator. Above the open-loop cavity bandwidth, feedback processes transfer that noise to the high power drive amplifiers. The LCLS-II project is expected to use an undulator to provide soft X-rays based on a stable electron beam accelerated by a superconducting linac. Project success depends on a low noise, low crosstalk analog to digital conversion. We developed a digitizer board with 8 ADC channels and 2 DAC channels. The broadband phase noise of this board is measured at <-151\thinspace dBc/Hz, and the adjacent channel crosstalk is measured at <-80\thinspace dB. In this paper we describe the digitizer board design, performance test procedures, and bench-test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA40
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TUPOA52	Updates to the Low-Level RF Architecture for Fermilab	ion, controls, simulation, hardware	394
	J. Einstein, B.E. Chase, E. Cullerton, P. Varghese Fermilab, Batavia, Illinois, USA S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA D. Sharma RRCAT, Indore (M.P.), India
	Fermilab has teamed with Colorado State University on several projects in LLRF controls and architecture. These projects include new LLRF hardware, updated controls techniques, and new system architectures. Here we present a summary of our work to date.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA52
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TUPOA63	Preliminary Study of Advanced LLRF Controls at LANSCE for Beam Loading Compensation in the MaRIE X-FEL	ion, controls, beam-loading, FPGA	411
	A. Scheinker, S.A. Baily, J.T. Bradley III, L.J. Castellano, J.O. Hill, D.J. Knapp, S. Kwon, J.T.M. Lyles, M.S. Prokop, D. Rees, P.A. Torrez LANL, Los Alamos, New Mexico, USA
	The analog low level RF (LLRF) control system of the Los Alamos Neutron Science Center is being upgraded to a Field Programmable Gate Array (FPGA)-based digital system (DLLRF). In this paper we give an overview of the FPGA design and the overall DLLRF system. We also present preliminary performance measurements including results utilizing model-independent iterative feedforward for beam-loading transient minimization, which is being studied for utilization in the future MaRIE X-FEL, which will face difficult beam loading conditions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA63
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FRA2IO02	High Precision RF Control for the LCLS-II	ion, cavity, controls, feedback	1292
	G. Huang, K. Campbell, L.R. Doolittle, J.A. Jones, C. Serrano, V.K. Vytla LBNL, Berkeley, California, USA S. Babel, M. Boyes, G.W. Brown, D. Cha, B. Hong, A. Ratti, C.H. Rivetta SLAC, Menlo Park, California, USA R. Bachimanchi, C. Hovater, D.J. Seidman JLab, Newport News, Virginia, USA B.E. Chase, E. Cullerton, Q. Du, J. Einstein, D.W. Klepec Fermilab, Batavia, Illinois, USA
	Funding: Work supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515 The LCLS-II is a CW superconducting linac under construction to drive an X-ray FEL. The energy and timing stability requirements of the FEL drive the need for very high precision RF control. This paper summarize the design considerations and early demonstration of the performance of the components and system we developed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-FRA2IO02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPOA12

An Updated LLRF Control System for the TLS Linac

ion, controls, linac, EPICS

308

C.Y. Wu, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Liao
NSRRC, Hsinchu, Taiwan

The amplitude and phase of the RF field at the linear accelerator (LINAC) decides the beam quality. To study and to improve the performance of the LINAC system for Taiwan Light Source (TLS), a new design of a low-level radio-frequency (LLRF) control system was developed and set up for the TLS LINAC. The main components of the LLRF control system are an I/Q modulator, an Ethernet-based arbitrary waveform generator, a digital oscilloscope and an I/Q demodulator; these are essential parts of the LLRF feed-forward control. This paper presents the efforts to improve the LLRF control system. The feasibility of the RF feed-forward control will be studied at the linear accelerator of TLS.

Poster TUPOA12 [1.425 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA12

Export •

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

TUPOA18

Low Level RF Control for the PIP-II Injector Test RFQ

ion, rfq, controls, cavity

323

J.P. Edelen, B.E. Chase, E. Cullerton, J. Einstein, P. Varghese
Fermilab, Batavia, Illinois, USA

The PIP-II injector test radio frequency quadrupole (RFQ) arrived at Fermilab in the fall of 2015. The RFQ is a 162.5MHz H⁻ accelerator with a nominal drive power of 100kW, which produces a bunched H⁻ beam at 2.1MeV. In this paper we discuss commissioning, operational performance, and improvements to the low level RF (LLRF) control system for the RFQ. We begin by describing the general system configuration and initial simulation results. We will then highlight temperature related issues in the high power RF system, which necessitate active control over the phase balance of the two amplifiers. Finally we demonstrate performance of the RF feedback and feed-forward compensation needed to meet specification during a 20-microsecond beam pulse.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA18

Export •

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

TUPOA40

Low Noise Digitizer Design for LCLS-II LLRF

ion, FPGA, cavity, hardware

364

G. Huang, L.R. Doolittle, Y.L. Xu, J. Yang
LBNL, Berkeley, California, USA
Y.L. Xu, J. Yang
TUB, Beijing, People's Republic of China

Modern accelerators use a digital low level RF controller to stabilize the fields in accelerator cavities. The noise in the receiver chain and analog to digital conversion (ADC) for the cavity probe signal is critically important. Within the closed-loop bandwidth, it will eventually become part of the field noise seen by the beam in the accelerator. Above the open-loop cavity bandwidth, feedback processes transfer that noise to the high power drive amplifiers. The LCLS-II project is expected to use an undulator to provide soft X-rays based on a stable electron beam accelerated by a superconducting linac. Project success depends on a low noise, low crosstalk analog to digital conversion. We developed a digitizer board with 8 ADC channels and 2 DAC channels. The broadband phase noise of this board is measured at <-151\thinspace dBc/Hz, and the adjacent channel crosstalk is measured at <-80\thinspace dB. In this paper we describe the digitizer board design, performance test procedures, and bench-test results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA40

Export •

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

TUPOA52

Updates to the Low-Level RF Architecture for Fermilab

ion, controls, simulation, hardware

394

J. Einstein, B.E. Chase, E. Cullerton, P. Varghese
Fermilab, Batavia, Illinois, USA
S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
D. Sharma
RRCAT, Indore (M.P.), India

Fermilab has teamed with Colorado State University on several projects in LLRF controls and architecture. These projects include new LLRF hardware, updated controls techniques, and new system architectures. Here we present a summary of our work to date.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA52

Export •

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

TUPOA63

Preliminary Study of Advanced LLRF Controls at LANSCE for Beam Loading Compensation in the MaRIE X-FEL

ion, controls, beam-loading, FPGA

411

A. Scheinker, S.A. Baily, J.T. Bradley III, L.J. Castellano, J.O. Hill, D.J. Knapp, S. Kwon, J.T.M. Lyles, M.S. Prokop, D. Rees, P.A. Torrez
LANL, Los Alamos, New Mexico, USA

The analog low level RF (LLRF) control system of the Los Alamos Neutron Science Center is being upgraded to a Field Programmable Gate Array (FPGA)-based digital system (DLLRF). In this paper we give an overview of the FPGA design and the overall DLLRF system. We also present preliminary performance measurements including results utilizing model-independent iterative feedforward for beam-loading transient minimization, which is being studied for utilization in the future MaRIE X-FEL, which will face difficult beam loading conditions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA63

Export •

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

FRA2IO02

High Precision RF Control for the LCLS-II

ion, cavity, controls, feedback

1292

G. Huang, K. Campbell, L.R. Doolittle, J.A. Jones, C. Serrano, V.K. Vytla
LBNL, Berkeley, California, USA
S. Babel, M. Boyes, G.W. Brown, D. Cha, B. Hong, A. Ratti, C.H. Rivetta
SLAC, Menlo Park, California, USA
R. Bachimanchi, C. Hovater, D.J. Seidman
JLab, Newport News, Virginia, USA
B.E. Chase, E. Cullerton, Q. Du, J. Einstein, D.W. Klepec
Fermilab, Batavia, Illinois, USA

Funding: Work supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515
The LCLS-II is a CW superconducting linac under construction to drive an X-ray FEL. The energy and timing stability requirements of the FEL drive the need for very high precision RF control. This paper summarize the design considerations and early demonstration of the performance of the components and system we developed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-FRA2IO02

Export •

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