IPAC2016 - Classification: 06 Beam Instrumentation, Controls, Feedback and Operational Aspects / T27 Low Level RF

Paper	Title	Page
WEPOR033	Progress in the Work on the Tuner Control System of the cERL at KEK	2742
	F. Qiu, T. Matsumoto, S. Michizono, T. Miura KEK, Ibaraki, Japan S.B. Wibowo Sokendai, Ibaraki, Japan
	A compact energy recovery linac (cERL), which is a test machine for future 3 GeV ERL project, was constructed at KEK. Five superconducting (SC) cavities were installed in the injector and main linac of the cERL. The SC cavities in cERL are prone to detuning by disturbances such as microphonics. Therefore, a piezo-based tuner system was used to compensate for the detuning of the SC cavity in the cERL. We have proposed advanced control methods that aim at improving the performance of the cERL tuner systems. In this paper, we present the progress in our work on the cERL tuner systems. The preliminary results of the beam-commissioning are also presented.
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WEPOR034	Design and Evaluation of a Broad Band microTCA.4 Based Downconverter	2746
SUPSS084	use link to see paper's listing under its alternate paper code
	N. Gan, Y.L. Chi, R.L. Liu, X. Ma IHEP, Beijing, People's Republic of China
	Modern low-level RF (LLRF) control systems of particle accelerators are designed to achieve extremely precise field amplitude and phase regulation inside the accelerating cavities, the RF field signal is usually converted to an intermediate frequency (IF) before being sampled by ADC. As the down-conversion is an important procedure of the digital signal processing in LLRF system, designing a high performance and broad band downconverter compatible with various accelerators will be significant. In this paper, the design of a MicroTCA based downconverter is presented, the major design objective of this module is wider operating frequency range and more flexibility in application. Several performance evaluations on different frequency points of this module have been conducted and the module presents a good performance in the operating frequency range.
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WEPOR035	MicroTCA.4-Based LLRF System for Spoke Cavities of C-ADS Injector I	2749
	X. Ma, N. Gan, X. Huang, N. Liu, R.L. Liu, G.W. Wang, Q.Y. Wang IHEP, Beijing, People's Republic of China H.Y. Lin Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	The C-ADS Injector I is being built in IHEP, which includes 14 β=0.12 superconducting single spoke cavities enclosed with two cryomodules under 2 K. The MicroTCA.4-based Low Level RF (LLRF) system provides GDR mode for the operation of the cavities. The LLRF system supports both CW and duty-adjustable pulsed operation modes for the high power source and the cavities. The firmware of the FPGA controller and the EPICS IOC software has been upgraded during the last half year adding feedforward and abnormal detection. The operator interface (OPI) software and automatic operation script are also described. The MicroTCA.4 platform runs well for the beam commissioning of the Injector I. Some gained experiences with stable beam operation are also shown.
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WEPOR036	Design and Commissioning of LLRF System for ADS Project in China	2752
	R.L. Liu, Y.L. Chi, N. Gan, X. Huang, N. Liu, X. Ma, Z.H. Mi, G.W. Wang, Q.Y. Wang, S.Z. Wang, Z.S. Zhou IHEP, Beijing, People's Republic of China H.Y. Lin Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	This article describes a low-level RF control system for the ADS project at IHEP, which includes control units for an RFQ, 2 Bunchers and 14 spoke superconducting cavities with the reference line distribution. The paper covers system design consideration and implementation for those units. we will also presented some experience and results for the last one year operation of these LLRF systems.
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WEPOR037	Beam Loading Effects in SSRF Storage Ring	2755
SUPSS085	use link to see paper's listing under its alternate paper code
	Y. Xia, Q. Chang, Z. Li, K. Xu, Zh.G. Zhang, S.J. Zhao, Y.B. Zhao, X. Zheng SINAP, Shanghai, People's Republic of China
	The beam current in the storage ring of Shanghai Synchrotron Radiation Facility (SSRF) is now normally 240 mA and projected to be raised to 300 mA. Heavy beam loading will be serious and associated Robinson instability needs to be compressed. In this paper, the beam loading effects in SSRF storage ring and methods to increase current limit will be discussed. .
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WEPOR039	Development of 200 MHz Digital LLRF System for the 1 MeV/n RFQ at KOMAC	2758
	H.S. Jeong, T.S. Ahn, Y.-S. Cho, H.S. Kim, S.G. Kim, H.-J. Kwon Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea Y.G. Song KAERI, Daejon, Republic of Korea
	KOMAC (Korea Multi-purpose Accelerator Complex) has a plan to develop the multipurpose ion irradiation system. This system includes the ion source, LEBT, RFQ and MEBT systems to transport ion particles to the target. In particular, the RFQ (Radio Frequency Quadrupole) system should receive 200 MHz RF within 1% amplitude error stability. To supply stable 200 MHz RF signal to the RFQ cavity, the LLRF (Low-Level Radio Frequency) system should be controlled through a control system which implemented using commercial digital board. This 1 MeV/n RFQ LLRF system has a concept to minimize the number of the analog components for minimizing the control error. For this, the FPGA (Field Programmable Gate Array) in the digital board will control the frequency of the output sinusoidal signal. In addition, this LLRF system applied the direct sampling, Non-IQ sampling, direct RF generation and fast IQ set update rate algorithm. In this presentation, the FPGA control logics of the LLRF digital board will be introduced. Also, the LLRF PI control logic test using 200 MHz dummy cavity will be described.
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WEPOR040	LLRF Development for PAL-XFEL	2761
	J. Hu, W.H. Hwang, H.-S. Kang, H.-S. Lee, C.-K. Min, G. Mun PAL, Pohang, Kyungbuk, Republic of Korea J.H. Chang, J.S. Han, Y.S. Kim RFPT, Gyeonggi-do, Republic of Korea O.J. Kim, H.S. Lee Mobiis Co., Ltd., Seoul, Republic of Korea
	PAL-XFEL construction is completed. Now, beam commissioning is ongoing after RF conditioning. The LLRF and SSA systems installed and in normal operation are presented. Those structures, features, characteristics, and performances are described.
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WEPOR042	LLRF Control of High Loaded-Q Cavities for the LCLS-II	2765
	C. Serrano, L.R. Doolittle, G. Huang, A. Ratti LBNL, Berkeley, California, USA S. Babel, M. Boyes, B. Hong SLAC, Menlo Park, California, USA R. Bachimanchi, C. Hovater JLab, Newport News, Virginia, USA B.E. Chase, E. Cullerton, J. Einstein Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515 The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW Superconducting Radio Frequency (SCRF) linac. The nature of the machine places stringent requirements in the Low-Level RF (LLRF) system, expected to control the cavity fields within 0.01 degrees in phase and 0.01% in amplitude, which is equivalent to a longitudinal motion of the cavity structure in the nanometer range. This stability has been achieved in the past but never for hundreds of superconducting cavities in Continuous-Wave (CW) operation. The difficulty resides in providing the ability to reject disturbances from the cryomodule, which is incompletely known as it depends on the cryomodule structure itself (currently under development at JLab and Fermilab) and the harsh accelerator environment. Previous experience in the field and an extrapolation to the cavity design parameters (relatively high Q_Lc≈ 4×10⁷ , implying a half-bandwidth of around 16 Hz) suggest the use of strong RF feedback to reject the projected noise disturbances, which in turn demands careful engineering of the entire system.
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WEPOR044	Fpga Implementation of a Control System for the LANSCE Accelerator	2771
	S. Kwon, L.J. Castellano, D.J. Knapp, J.T.M. Lyles, M.S. Prokop, D. Rees, A. Scheinker, P.A. Torrez LANL, Los Alamos, New Mexico, USA
	As part of the modernization of the Los Alamos Neutron Science Center (LANSCE), a digital low level RF (LLRF) system was designed. The LLRF control system was implemented in a Field Programmable Gate Array (FPGA) using embedded Experimental Physics and Industrial Control System (EPICS) Input Output Controller (IOC) under the Real-Time Executive for Multiprocessor Systems (RTEMS). Proportional-Integral (PI) feedback controller, static beam feedforward controller, and iterative learning controller are implemented on the FPGA. The closed loop system performance was tested with a 10mA peak current proton beam.
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THOAA03	MicroTCA.4 based Single Cavity Regulation including Piezo Controls	3152
	K.P. Przygoda, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany P. Echevarria HZB, Berlin, Germany R. Rybaniec Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
	We want to summarize the single cavity regulation with MTCA.4 electronics. Presented solution is based on the one MTCA.4 crate integrating both RF field control and piezo tuner control systems. The RF field control electronics consists of RTM for cavity probes sensing and high voltage power source driving, AMC for fast data processing and digital feedback operation. The piezo control system has been setup with high voltage RTM Piezo driver and low cost AMC based FMC carrier. The communication between both control systems is performed using low latency link over the AMC backplane with data throughput up to the 3.125 Gbps. First results from CW operation of the RF field controller and the cavity active resonance control with the piezo tuners are demonstrated and briefly discussed.
	Slides THOAA03 [2.693 MB]
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Paper

Title

Page

Progress in the Work on the Tuner Control System of the cERL at KEK

2742

F. Qiu, T. Matsumoto, S. Michizono, T. Miura
KEK, Ibaraki, Japan
S.B. Wibowo
Sokendai, Ibaraki, Japan

A compact energy recovery linac (cERL), which is a test machine for future 3 GeV ERL project, was constructed at KEK. Five superconducting (SC) cavities were installed in the injector and main linac of the cERL. The SC cavities in cERL are prone to detuning by disturbances such as microphonics. Therefore, a piezo-based tuner system was used to compensate for the detuning of the SC cavity in the cERL. We have proposed advanced control methods that aim at improving the performance of the cERL tuner systems. In this paper, we present the progress in our work on the cERL tuner systems. The preliminary results of the beam-commissioning are also presented.

Export •

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

WEPOR034

Design and Evaluation of a Broad Band microTCA.4 Based Downconverter

2746

SUPSS084

use link to see paper's listing under its alternate paper code

N. Gan, Y.L. Chi, R.L. Liu, X. Ma
IHEP, Beijing, People's Republic of China

Modern low-level RF (LLRF) control systems of particle accelerators are designed to achieve extremely precise field amplitude and phase regulation inside the accelerating cavities, the RF field signal is usually converted to an intermediate frequency (IF) before being sampled by ADC. As the down-conversion is an important procedure of the digital signal processing in LLRF system, designing a high performance and broad band downconverter compatible with various accelerators will be significant. In this paper, the design of a MicroTCA based downconverter is presented, the major design objective of this module is wider operating frequency range and more flexibility in application. Several performance evaluations on different frequency points of this module have been conducted and the module presents a good performance in the operating frequency range.

Export •

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

WEPOR035

MicroTCA.4-Based LLRF System for Spoke Cavities of C-ADS Injector I

2749

X. Ma, N. Gan, X. Huang, N. Liu, R.L. Liu, G.W. Wang, Q.Y. Wang
IHEP, Beijing, People's Republic of China
H.Y. Lin
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

The C-ADS Injector I is being built in IHEP, which includes 14 β=0.12 superconducting single spoke cavities enclosed with two cryomodules under 2 K. The MicroTCA.4-based Low Level RF (LLRF) system provides GDR mode for the operation of the cavities. The LLRF system supports both CW and duty-adjustable pulsed operation modes for the high power source and the cavities. The firmware of the FPGA controller and the EPICS IOC software has been upgraded during the last half year adding feedforward and abnormal detection. The operator interface (OPI) software and automatic operation script are also described. The MicroTCA.4 platform runs well for the beam commissioning of the Injector I. Some gained experiences with stable beam operation are also shown.

Export •

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

WEPOR036

Design and Commissioning of LLRF System for ADS Project in China

2752

R.L. Liu, Y.L. Chi, N. Gan, X. Huang, N. Liu, X. Ma, Z.H. Mi, G.W. Wang, Q.Y. Wang, S.Z. Wang, Z.S. Zhou
IHEP, Beijing, People's Republic of China
H.Y. Lin
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

This article describes a low-level RF control system for the ADS project at IHEP, which includes control units for an RFQ, 2 Bunchers and 14 spoke superconducting cavities with the reference line distribution. The paper covers system design consideration and implementation for those units. we will also presented some experience and results for the last one year operation of these LLRF systems.

Export •

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

WEPOR037

Beam Loading Effects in SSRF Storage Ring

2755

SUPSS085

use link to see paper's listing under its alternate paper code

Y. Xia, Q. Chang, Z. Li, K. Xu, Zh.G. Zhang, S.J. Zhao, Y.B. Zhao, X. Zheng
SINAP, Shanghai, People's Republic of China

The beam current in the storage ring of Shanghai Synchrotron Radiation Facility (SSRF) is now normally 240 mA and projected to be raised to 300 mA. Heavy beam loading will be serious and associated Robinson instability needs to be compressed. In this paper, the beam loading effects in SSRF storage ring and methods to increase current limit will be discussed. .

Export •

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

WEPOR039

Development of 200 MHz Digital LLRF System for the 1 MeV/n RFQ at KOMAC

2758

H.S. Jeong, T.S. Ahn, Y.-S. Cho, H.S. Kim, S.G. Kim, H.-J. Kwon
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
Y.G. Song
KAERI, Daejon, Republic of Korea

KOMAC (Korea Multi-purpose Accelerator Complex) has a plan to develop the multipurpose ion irradiation system. This system includes the ion source, LEBT, RFQ and MEBT systems to transport ion particles to the target. In particular, the RFQ (Radio Frequency Quadrupole) system should receive 200 MHz RF within 1% amplitude error stability. To supply stable 200 MHz RF signal to the RFQ cavity, the LLRF (Low-Level Radio Frequency) system should be controlled through a control system which implemented using commercial digital board. This 1 MeV/n RFQ LLRF system has a concept to minimize the number of the analog components for minimizing the control error. For this, the FPGA (Field Programmable Gate Array) in the digital board will control the frequency of the output sinusoidal signal. In addition, this LLRF system applied the direct sampling, Non-IQ sampling, direct RF generation and fast IQ set update rate algorithm. In this presentation, the FPGA control logics of the LLRF digital board will be introduced. Also, the LLRF PI control logic test using 200 MHz dummy cavity will be described.

Export •

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

WEPOR040

LLRF Development for PAL-XFEL

2761

J. Hu, W.H. Hwang, H.-S. Kang, H.-S. Lee, C.-K. Min, G. Mun
PAL, Pohang, Kyungbuk, Republic of Korea
J.H. Chang, J.S. Han, Y.S. Kim
RFPT, Gyeonggi-do, Republic of Korea
O.J. Kim, H.S. Lee
Mobiis Co., Ltd., Seoul, Republic of Korea

PAL-XFEL construction is completed. Now, beam commissioning is ongoing after RF conditioning. The LLRF and SSA systems installed and in normal operation are presented. Those structures, features, characteristics, and performances are described.

Export •

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

WEPOR042

LLRF Control of High Loaded-Q Cavities for the LCLS-II

2765

C. Serrano, L.R. Doolittle, G. Huang, A. Ratti
LBNL, Berkeley, California, USA
S. Babel, M. Boyes, B. Hong
SLAC, Menlo Park, California, USA
R. Bachimanchi, C. Hovater
JLab, Newport News, Virginia, USA
B.E. Chase, E. Cullerton, J. Einstein
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515
The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW Superconducting Radio Frequency (SCRF) linac. The nature of the machine places stringent requirements in the Low-Level RF (LLRF) system, expected to control the cavity fields within 0.01 degrees in phase and 0.01% in amplitude, which is equivalent to a longitudinal motion of the cavity structure in the nanometer range. This stability has been achieved in the past but never for hundreds of superconducting cavities in Continuous-Wave (CW) operation. The difficulty resides in providing the ability to reject disturbances from the cryomodule, which is incompletely known as it depends on the cryomodule structure itself (currently under development at JLab and Fermilab) and the harsh accelerator environment. Previous experience in the field and an extrapolation to the cavity design parameters (relatively high Q_Lc≈ 4×10⁷ , implying a half-bandwidth of around 16 Hz) suggest the use of strong RF feedback to reject the projected noise disturbances, which in turn demands careful engineering of the entire system.

Export •

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

WEPOR044

Fpga Implementation of a Control System for the LANSCE Accelerator

2771

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

As part of the modernization of the Los Alamos Neutron Science Center (LANSCE), a digital low level RF (LLRF) system was designed. The LLRF control system was implemented in a Field Programmable Gate Array (FPGA) using embedded Experimental Physics and Industrial Control System (EPICS) Input Output Controller (IOC) under the Real-Time Executive for Multiprocessor Systems (RTEMS). Proportional-Integral (PI) feedback controller, static beam feedforward controller, and iterative learning controller are implemented on the FPGA. The closed loop system performance was tested with a 10mA peak current proton beam.

Export •

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

THOAA03

MicroTCA.4 based Single Cavity Regulation including Piezo Controls

3152

K.P. Przygoda, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
P. Echevarria
HZB, Berlin, Germany
R. Rybaniec
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland

We want to summarize the single cavity regulation with MTCA.4 electronics. Presented solution is based on the one MTCA.4 crate integrating both RF field control and piezo tuner control systems. The RF field control electronics consists of RTM for cavity probes sensing and high voltage power source driving, AMC for fast data processing and digital feedback operation. The piezo control system has been setup with high voltage RTM Piezo driver and low cost AMC based FMC carrier. The communication between both control systems is performed using low latency link over the AMC backplane with data throughput up to the 3.125 Gbps. First results from CW operation of the RF field controller and the cavity active resonance control with the piezo tuners are demonstrated and briefly discussed.

Slides THOAA03 [2.693 MB]

Export •

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