LINAC2012 - List of Keywords (LLRF)

Paper	Title	Other Keywords	Page
MOPB020	LLRF System Improvement for HLS Linac Upgrade	linac, controls, feedback, low-level-rf	213
	G. Huang, D. Jia, K. Jin, H. Lin, Weishi, Zhou. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China Y. Liu USTC, Hefei, Anhui, People's Republic of China
	Funding: supported by NSFC-CAS Joint Fund, contract no. 11079034 The linac beam energy will be upgraded from 200 MeV to 800 MeV, in order to realize the full-energy injection of storage ring at Hefei Light Source. This paper introduces the improvement of linac LLRF system, which is composed of phase reference and driver signal transmission and distribution, auto-phasing system, phase reversal device for SLED. the LLRF prototype has been constructed, and the test results is described in the paper.

MOPB054	Test Results of Tesla-style Cryomodules at Fermilab	cryomodule, cavity, SRF, controls	297
	E.R. Harms, K. Carlson, B. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, Jr, A. Hocker, M.J. Kucera, J.R. Leibfritz, O.A. Nezhevenko, D.J. Nicklaus, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, P. Varghese Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Commissioning and operation of the first Tesla-style Cryomodule (CM-1) at Fermilab was concluded in recent months. It has now been replaced by a second Tesla Type III+ module, RFCA002. It is the first 8-cavity ILC style cryomodule to be built at Fermilab and also the first accelerating cryomodule of the Advanced Superconducting Test Accelerator (ASTA). We report on the operating results of both of these cryomodules.

MOPB083	Operational experience with the FERMI@Elettra S-band RF System	FEL, klystron, linac, gun	369
	A. Fabris, P. Delgiusto, F. Gelmetti, M.M. Milloch, A. Milocco, F. Pribaz, C. Serpico, N. Sodomaco, R. Umer, L. Veljak ELETTRA, Basovizza, Italy
	FERMI@Elettra is a single-pass linac-based FEL user-facility covering the wavelength range from 100 nm (12 eV) to 4 nm (310 eV) and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The machine is presently under commissioning and the first FEL line (FEL-1) will be opened to the users by the end of 2012. The 1.5 GeV linac is based on S-band technology. The S-band system is composed of fifteen 3 GHz 45 MW peak RF power plants powering the gun, eighteen accelerating structures and the RF deflectors. The S-band system has been set into operation in different phases starting from the second half of 2009. This paper provides an overview of the performance of the system, discussing the achieved results, the strategies adopted to assure them and possible upgrade paths to increase the operability and safety margins of the system.

TUPB019	Second CW and LP Operation Test of XFEL Prototype Cryomodule	cryomodule, feedback, cavity, HOM	516
	J.K. Sekutowicz, V. Ayvazyan, J. Branlard, M. Ebert, J. Eschke, A. Gössel, D. Kostin, W. Merz, F. Mittag, R. Onken DESY, Hamburg, Germany W. Cichalewski, W. Jałmużna, A. Piotrowski, K.P. Przygoda TUL-DMCS, Łódź, Poland K. Czuba, L. Zembala Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland I.M. Kudla, J. Szewiński NCBJ, Świerk/Otwock, Poland
	In summer 2011, we have performed the first test of continuous wave (cw) and long pulse (lp) operation of the XFEL prototype cryomodule, which originally has been designed for short pulse operation. In April and June 2012, the second test took place, with the next cryomodule prototype. For that test cooling in the cryomodule was improved and new LLRF system has been implemented. In this contribution we discuss results of the second RF test of these new types of operation, which can in the future extend flexibility in the time beam structure of the European XFEL facility

TUPB061	ADRC Control for Beam Loading and Microphonics	controls, cavity, beam-loading, simulation	615
	Z. Zheng, Z. Liu, J. Wei, Y. Zhang, S. Zhao FRIB, East Lansing, Michigan, USA Z. Zheng TUB, Beijing, People's Republic of China
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Superconducting RF (SRF) cavities are subject to many disturbances such as beam loading and microphonics. Although we implemented Proportional Integral (PI) control and Active Disturbance Rejection Control (ADRC) in the Low Level RF (LLRF) system at FRIB to stabilize the RF field, the control loop gains are inadequate in the presence of beam loading and microphonics. An improved scheme is proposed and simulated with much higher gains are achieved. The feasibility to include piezo tuner in ADRC and PI circuit is also presented in this paper.

TH1A01	Results Achieved by the S1-Global Collaboration for ILC	cavity, cryomodule, controls, feedback	748
	H. Hayano, M. Akemoto, S. Fukuda, K. Hara, N. Higashi, E. Kako, H. Katagiri, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, N. Ohuchi, T. Saeki, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya KEK, Ibaraki, Japan C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA T.T. Arkan, S. Barbanotti, M.A. Battistoni, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross, W. Schappert, B.E. Smith Fermilab, Batavia, USA A. Bosotti, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy K. Jensch, D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	The S1-Global collaboration (scope and plans presented at Linac10) ended successfully in 2011. In the S1-Global experiment several variants of ILC components (e.g. cavities, tuners, modules, couplers) proposed by all SCRF collaborators worldwide have been extensively tested and their performances compared, in order to build consensus for the technical choices towards the ILC TDR and to develop further the concept of plug-compatible components for ILC. The experiment has been carried at KEK with contribution of hardware and manpower from all collaborators.
	Slides TH1A01 [6.656 MB]

THPLB02	Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test	cavity, controls, klystron, rfq	810
	P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan Fermilab, Batavia, USA
	The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.
	Slides THPLB02 [1.610 MB]

THPB015	Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test	cavity, controls, klystron, rfq	879
	P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan Fermilab, Batavia, USA
	The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

THPB022	Beam Phase Measurement for PEFP Linear Accelerator	linac, DTL, simulation, proton	894
	H.S. Kim, Y.-S. Cho, J.-H. Jang, H.-J. Kwon, J.Y. Ryu, K.T. Seol, Y.-G. Song KAERI, Daejon, Republic of Korea
	Funding: Works supported by the Ministry of Education, Science and Technology of Korean Government. According to the commissioning plan of the PEFP proton linac, an accurate measurement of beam phase is essential, especially for setting up the RF operating parameters of DTL. Beam position monitors (BPMs) installed between DTL tanks can provide information about the beam phase as well as about the beam transverse position. By using a BPM as a beam phase monitor, beam phase can be measured without additional devices on the linac or the beam line. The signals from 4 electrodes in the BPM can be summed by using a 4-way RF combiner, by which the effect of the transverse beam offset on the phase measurement can be eliminated. The combined BPM signal (350 MHz) is mixed with LO signal (300 MHz) and down-converted to IF signal (50 MHz), then fed into the signal processing unit, where the phase information is extracted by using IQ demodulation method with a sampling frequency of 40 MHz. In this paper, the beam phase measurement system and signal processing scheme will be presented.

THPB084	A Low-Level RF Control System for a Quarter-Wave Resonator	controls, cavity, resonance, ion	1020
	J.-W. Kim, D.G. Kim IBS, Daejeon, Republic of Korea C.K. Hwang KAERI, Daejon, Republic of Korea
	A low-level rf control system was designed and built for an rf deflector, which is a quarter wave resonator and was designed to deflect a secondary electron beam to measure the bunch length of an ion beam. The deflector has a resonance frequency at near 88 MHz, and its required phase stability is approximately ±1° and amplitude stability less than ±1%. The control system consists of analog input and output components, and a digital system based on an FPGA for signal processing. It is a cost effective system, while meeting the stability requirements. Some basic properties of the control system were measured. Then the capability of the rf control has been tested using a mechanical vibrator made of a dielectric rod attached to an audio speaker system, which can induce regulated perturbation in the electric fields of the resonator. The control system is flexible such that its parameters can be easily configured to compensate for disturbance induced in the resonator.

THPB086	Precision Regulation of RF Fields with MIMO Controllers and Cavity-based Notch Filters	cavity, controls, resonance, feedback	1026
	Ch. Schmidt, J. Branlard, S. Pfeiffer, H. Schlarb DESY, Hamburg, Germany W. Jałmużna TUL-DMCS, Łódź, Poland
	The European XFEL requires a high precision control of the electron beam, generating a specific pulsed laser light demanded by user experiments. The low level radio frequency (LLRF) control system is certainly one of the key players for the regulation of accelerating RF fields. A uTCA standard LLRF system was developed and is currently under test at DESY. Its first experimental results showed the system performance capabilities. Investigation of regulation limiting factors evidenced the need for control over fundamental cavity modes, which is done using complex controller structures and filter techniques. The improvement in measurement accuracy and detection bandwidth increased the regulation performance and contributed to integration of further control subsystems.

Paper

Title

Other Keywords

Page

MOPB020

LLRF System Improvement for HLS Linac Upgrade

linac, controls, feedback, low-level-rf

213

G. Huang, D. Jia, K. Jin, H. Lin, Weishi, Zhou. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China
Y. Liu
USTC, Hefei, Anhui, People's Republic of China

Funding: supported by NSFC-CAS Joint Fund, contract no. 11079034
The linac beam energy will be upgraded from 200 MeV to 800 MeV, in order to realize the full-energy injection of storage ring at Hefei Light Source. This paper introduces the improvement of linac LLRF system, which is composed of phase reference and driver signal transmission and distribution, auto-phasing system, phase reversal device for SLED. the LLRF prototype has been constructed, and the test results is described in the paper.

MOPB054

Test Results of Tesla-style Cryomodules at Fermilab

cryomodule, cavity, SRF, controls

297

E.R. Harms, K. Carlson, B. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, Jr, A. Hocker, M.J. Kucera, J.R. Leibfritz, O.A. Nezhevenko, D.J. Nicklaus, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, P. Varghese
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Commissioning and operation of the first Tesla-style Cryomodule (CM-1) at Fermilab was concluded in recent months. It has now been replaced by a second Tesla Type III+ module, RFCA002. It is the first 8-cavity ILC style cryomodule to be built at Fermilab and also the first accelerating cryomodule of the Advanced Superconducting Test Accelerator (ASTA). We report on the operating results of both of these cryomodules.

MOPB083

Operational experience with the FERMI@Elettra S-band RF System

FEL, klystron, linac, gun

369

A. Fabris, P. Delgiusto, F. Gelmetti, M.M. Milloch, A. Milocco, F. Pribaz, C. Serpico, N. Sodomaco, R. Umer, L. Veljak
ELETTRA, Basovizza, Italy

FERMI@Elettra is a single-pass linac-based FEL user-facility covering the wavelength range from 100 nm (12 eV) to 4 nm (310 eV) and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The machine is presently under commissioning and the first FEL line (FEL-1) will be opened to the users by the end of 2012. The 1.5 GeV linac is based on S-band technology. The S-band system is composed of fifteen 3 GHz 45 MW peak RF power plants powering the gun, eighteen accelerating structures and the RF deflectors. The S-band system has been set into operation in different phases starting from the second half of 2009. This paper provides an overview of the performance of the system, discussing the achieved results, the strategies adopted to assure them and possible upgrade paths to increase the operability and safety margins of the system.

TUPB019

Second CW and LP Operation Test of XFEL Prototype Cryomodule

cryomodule, feedback, cavity, HOM

516

J.K. Sekutowicz, V. Ayvazyan, J. Branlard, M. Ebert, J. Eschke, A. Gössel, D. Kostin, W. Merz, F. Mittag, R. Onken
DESY, Hamburg, Germany
W. Cichalewski, W. Jałmużna, A. Piotrowski, K.P. Przygoda
TUL-DMCS, Łódź, Poland
K. Czuba, L. Zembala
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
I.M. Kudla, J. Szewiński
NCBJ, Świerk/Otwock, Poland

In summer 2011, we have performed the first test of continuous wave (cw) and long pulse (lp) operation of the XFEL prototype cryomodule, which originally has been designed for short pulse operation. In April and June 2012, the second test took place, with the next cryomodule prototype. For that test cooling in the cryomodule was improved and new LLRF system has been implemented. In this contribution we discuss results of the second RF test of these new types of operation, which can in the future extend flexibility in the time beam structure of the European XFEL facility

TUPB061

ADRC Control for Beam Loading and Microphonics

controls, cavity, beam-loading, simulation

615

Z. Zheng, Z. Liu, J. Wei, Y. Zhang, S. Zhao
FRIB, East Lansing, Michigan, USA
Z. Zheng
TUB, Beijing, People's Republic of China

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Superconducting RF (SRF) cavities are subject to many disturbances such as beam loading and microphonics. Although we implemented Proportional Integral (PI) control and Active Disturbance Rejection Control (ADRC) in the Low Level RF (LLRF) system at FRIB to stabilize the RF field, the control loop gains are inadequate in the presence of beam loading and microphonics. An improved scheme is proposed and simulated with much higher gains are achieved. The feasibility to include piezo tuner in ADRC and PI circuit is also presented in this paper.

TH1A01

Results Achieved by the S1-Global Collaboration for ILC

cavity, cryomodule, controls, feedback

748

H. Hayano, M. Akemoto, S. Fukuda, K. Hara, N. Higashi, E. Kako, H. Katagiri, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, N. Ohuchi, T. Saeki, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya
KEK, Ibaraki, Japan
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
T.T. Arkan, S. Barbanotti, M.A. Battistoni, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross, W. Schappert, B.E. Smith
Fermilab, Batavia, USA
A. Bosotti, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
K. Jensch, D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, P. Schilling, M. Schmökel, N.J. Walker, H. Weise
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

The S1-Global collaboration (scope and plans presented at Linac10) ended successfully in 2011. In the S1-Global experiment several variants of ILC components (e.g. cavities, tuners, modules, couplers) proposed by all SCRF collaborators worldwide have been extensively tested and their performances compared, in order to build consensus for the technical choices towards the ILC TDR and to develop further the concept of plug-compatible components for ILC. The experiment has been carried at KEK with contribution of hardware and manpower from all collaborators.

Slides TH1A01 [6.656 MB]

THPLB02

Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test

cavity, controls, klystron, rfq

810

P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan
Fermilab, Batavia, USA

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

Slides THPLB02 [1.610 MB]

THPB015

Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test

cavity, controls, klystron, rfq

879

P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan
Fermilab, Batavia, USA

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

THPB022

Beam Phase Measurement for PEFP Linear Accelerator

linac, DTL, simulation, proton

894

H.S. Kim, Y.-S. Cho, J.-H. Jang, H.-J. Kwon, J.Y. Ryu, K.T. Seol, Y.-G. Song
KAERI, Daejon, Republic of Korea

Funding: Works supported by the Ministry of Education, Science and Technology of Korean Government.
According to the commissioning plan of the PEFP proton linac, an accurate measurement of beam phase is essential, especially for setting up the RF operating parameters of DTL. Beam position monitors (BPMs) installed between DTL tanks can provide information about the beam phase as well as about the beam transverse position. By using a BPM as a beam phase monitor, beam phase can be measured without additional devices on the linac or the beam line. The signals from 4 electrodes in the BPM can be summed by using a 4-way RF combiner, by which the effect of the transverse beam offset on the phase measurement can be eliminated. The combined BPM signal (350 MHz) is mixed with LO signal (300 MHz) and down-converted to IF signal (50 MHz), then fed into the signal processing unit, where the phase information is extracted by using IQ demodulation method with a sampling frequency of 40 MHz. In this paper, the beam phase measurement system and signal processing scheme will be presented.

THPB084

A Low-Level RF Control System for a Quarter-Wave Resonator

controls, cavity, resonance, ion

1020

J.-W. Kim, D.G. Kim
IBS, Daejeon, Republic of Korea
C.K. Hwang
KAERI, Daejon, Republic of Korea

A low-level rf control system was designed and built for an rf deflector, which is a quarter wave resonator and was designed to deflect a secondary electron beam to measure the bunch length of an ion beam. The deflector has a resonance frequency at near 88 MHz, and its required phase stability is approximately ±1° and amplitude stability less than ±1%. The control system consists of analog input and output components, and a digital system based on an FPGA for signal processing. It is a cost effective system, while meeting the stability requirements. Some basic properties of the control system were measured. Then the capability of the rf control has been tested using a mechanical vibrator made of a dielectric rod attached to an audio speaker system, which can induce regulated perturbation in the electric fields of the resonator. The control system is flexible such that its parameters can be easily configured to compensate for disturbance induced in the resonator.

THPB086

Precision Regulation of RF Fields with MIMO Controllers and Cavity-based Notch Filters

cavity, controls, resonance, feedback

1026

Ch. Schmidt, J. Branlard, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
W. Jałmużna
TUL-DMCS, Łódź, Poland

The European XFEL requires a high precision control of the electron beam, generating a specific pulsed laser light demanded by user experiments. The low level radio frequency (LLRF) control system is certainly one of the key players for the regulation of accelerating RF fields. A uTCA standard LLRF system was developed and is currently under test at DESY. Its first experimental results showed the system performance capabilities. Investigation of regulation limiting factors evidenced the need for control over fundamental cavity modes, which is done using complex controller structures and filter techniques. The improvement in measurement accuracy and detection bandwidth increased the regulation performance and contributed to integration of further control subsystems.