ICALEPCS2011 - List of Keywords (cavity)

Paper	Title	Other Keywords	Page
MOPKS007	Design of a Digital Controller for ALPI 80 MHz Resonators	feedback, FPGA, controls, resonance	174
	S.V. Barabin ITEP, Moscow, Russia G. Bassato INFN/LNL, Legnaro (PD), Italy
	We discuss the design of a resonator controller completely based on digital technology. The controller is currently operating at 80 MHz but can be easily adapted to frequencies up to 350MHz; it can work either in "Generator Driven" and in "Self Excited Loop" mode. The signal processing unit is a commercial board (Bittware T2-Pci) with 4 TigerSharc DSPs and a Xilinx Virtex II-Pro FPGA. The front-end board includes five A/D channels supporting a sampling rate in excess of 100M/s and a clock distribution system with a jitter less than 10ps, allowing direct sampling of RF signals with no need of analog downconversion. We present the results of some preliminary tests carried out on a 80 MHz quarter wave resonator installed in the ALPI Linac accelerator at INFN-LNL and discuss possible developments of this project.
	Poster MOPKS007 [0.931 MB]

MOPKS020	Low Level RF Control System for Cyclotron 10 MeV	controls, feedback, cyclotron, low-level-rf	199
	J. Huang, D. Li, K.F. Liu Huazhong University of Science and Technology (HUST), Wuhan, People's Republic of China T. Hu HUST, Wuhan, People's Republic of China
	The low level RF control system consists of a 101MHz signal generator, three feedback loops, an interlock and a protection system. The stability of control system is one of the most important indicators in the cyclotron design, especially when the whole system has a high current. Due to the hugeness of the RF system and the complexity of control objects, the low level RF control system must combine the basic theory with the electronic circuit to optimize the whole system. The major obstacles in the research, which rarely exist in other control systems, lay in the coupling of beam and resonant cavity, requiring to be described by the transfer function between beam and cavity, the complex coupling between microwave devices and the interference signals of all loops. By introducing the three feedback loops (tuning loop, amplitude loop and phase loop) and test results from some parts of electric circuits, this paper unfolds the performance index and design of low level RF control system, which may contribute to the design of cyclotron with a high and reliable performance.

MOPMN016	The Spiral2 Radiofrequency Command Control	controls, interface, EPICS, LLRF	274
	D.T. Touchard, C. Berthe, P. Gillette, M. Lechartier, E. Lécorché, G. Normand GANIL, Caen, France Y. Lussignol, D. Uriot CEA/DSM/IRFU, France
	Mainly for carrying out nuclear physics experiences, the SPIRAL2 facility based at Caen in France will aim to provide new radioactive rare ion or high intensity stable ion beams. The driver accelerator uses several radiofrequency systems: RFQ, buncher and superconducting cavities, driven by independent amplifiers and controlled by digital electronics. This low level radiofrequency subsystem is integrated into a regulated loop driven by the control system. A test of a whole system is foreseen to define and check the computer control interface and applications. This paper describes the interfaces to the different RF equipment into the EPICS based computer control system. CSS supervision and foreseen high level tuning XAL/JAVA based applications are also considered.
	Poster MOPMN016 [0.986 MB]

WEBHMUST02	Solid State Direct Drive RF Linac: Control System	controls, experiment, software, LLRF	638
	T. Kluge, M. Back, U. Hagen, O. Heid, M. Hergt, T.J.S. Hughes, R. Irsigler, J. Sirtl Siemens AG, Erlangen, Germany R. Fleck Siemens AG, Corporate Technology, CT T DE HW 4, Erlangen, Germany H.-C. Schröder ASTRUM IT GmbH, Erlangen, Germany
	Recently a Solid State Direct Drive ® concept for RF linacs has been introduced [1]. This new approach integrates the RF source, comprised of multiple Silicon Carbide (SiC) solid state Rf-modules [2], directly onto the cavity. Such an approach introduces new challenges for the control of such machines namely the non-linear behavior of the solid state RF-modules and the direct coupling of the RF-modules onto the cavity. In this paper we discuss further results of the experimental program [3,4] to integrate and control 64 RF-modules onto a λ/4 cavity. The next stage of experiments aims on gaining better feed forward control of the system and on detailed system identification. For this purpose a digital control board comprising of a Virtex 6 FPGA, high speed DACs/ADCs and trigger I/O is developed and integrated into the experiment and used to control the system. The design of the board is consequently digital aiming at direct processing of the signals. Power control within the cavity is achieved by an outphasing control of two groups of the RF-modules. This allows a power control without degradation of RF-module efficiency. [1] Heid O., Hughes T., THPD002, IPAC10, Kyoto, Japan [2] Irsigler R. et al, 3B-9, PPC11, Chicago IL, USA [3] Heid O., Hughes T., THP068, LINAC10, Tsukuba, Japan [4] Heid O., Hughes T., MOPD42, HB2010, Morschach, Switzerland
	Slides WEBHMUST02 [1.201 MB]

WEPKS010	Architecture Design of the Application Software for the Low-Level RF Control System of the Free-Electron Laser at Hamburg	LLRF, controls, software, interface	798
	Z. Geng SLAC, Menlo Park, California, USA V. Ayvazyan DESY, Hamburg, Germany S. Simrock ITER Organization, St. Paul lez Durance, France
	The superconducting linear accelerator of the Free-Electron Laser at Hamburg (FLASH) provides high performance electron beams to the lasing system to generate synchrotron radiation to various users. The Low-Level RF (LLRF) system is used to maintain the beam stabilities by stabilizing the RF field in the superconducting cavities with feedback and feed forward algorithms. The LLRF applications are sets of software to perform RF system model identification, control parameters optimization, exception detection and handling, so as to improve the precision, robustness and operability of the LLRF system. In order to implement the LLRF applications in the hardware with multiple distributed processors, an optimized architecture of the software is required for good understandability, maintainability and extendibility. This paper presents the design of the LLRF application software architecture based on the software engineering approach and the implementation at FLASH.
	Poster WEPKS010 [0.307 MB]

Paper

Title

Other Keywords

Page

MOPKS007

Design of a Digital Controller for ALPI 80 MHz Resonators

feedback, FPGA, controls, resonance

174

S.V. Barabin
ITEP, Moscow, Russia
G. Bassato
INFN/LNL, Legnaro (PD), Italy

We discuss the design of a resonator controller completely based on digital technology. The controller is currently operating at 80 MHz but can be easily adapted to frequencies up to 350MHz; it can work either in "Generator Driven" and in "Self Excited Loop" mode. The signal processing unit is a commercial board (Bittware T2-Pci) with 4 TigerSharc DSPs and a Xilinx Virtex II-Pro FPGA. The front-end board includes five A/D channels supporting a sampling rate in excess of 100M/s and a clock distribution system with a jitter less than 10ps, allowing direct sampling of RF signals with no need of analog downconversion. We present the results of some preliminary tests carried out on a 80 MHz quarter wave resonator installed in the ALPI Linac accelerator at INFN-LNL and discuss possible developments of this project.

Poster MOPKS007 [0.931 MB]

MOPKS020

Low Level RF Control System for Cyclotron 10 MeV

controls, feedback, cyclotron, low-level-rf

199

J. Huang, D. Li, K.F. Liu
Huazhong University of Science and Technology (HUST), Wuhan, People's Republic of China
T. Hu
HUST, Wuhan, People's Republic of China

The low level RF control system consists of a 101MHz signal generator, three feedback loops, an interlock and a protection system. The stability of control system is one of the most important indicators in the cyclotron design, especially when the whole system has a high current. Due to the hugeness of the RF system and the complexity of control objects, the low level RF control system must combine the basic theory with the electronic circuit to optimize the whole system. The major obstacles in the research, which rarely exist in other control systems, lay in the coupling of beam and resonant cavity, requiring to be described by the transfer function between beam and cavity, the complex coupling between microwave devices and the interference signals of all loops. By introducing the three feedback loops (tuning loop, amplitude loop and phase loop) and test results from some parts of electric circuits, this paper unfolds the performance index and design of low level RF control system, which may contribute to the design of cyclotron with a high and reliable performance.

MOPMN016

The Spiral2 Radiofrequency Command Control

controls, interface, EPICS, LLRF

274

D.T. Touchard, C. Berthe, P. Gillette, M. Lechartier, E. Lécorché, G. Normand
GANIL, Caen, France
Y. Lussignol, D. Uriot
CEA/DSM/IRFU, France

Mainly for carrying out nuclear physics experiences, the SPIRAL2 facility based at Caen in France will aim to provide new radioactive rare ion or high intensity stable ion beams. The driver accelerator uses several radiofrequency systems: RFQ, buncher and superconducting cavities, driven by independent amplifiers and controlled by digital electronics. This low level radiofrequency subsystem is integrated into a regulated loop driven by the control system. A test of a whole system is foreseen to define and check the computer control interface and applications. This paper describes the interfaces to the different RF equipment into the EPICS based computer control system. CSS supervision and foreseen high level tuning XAL/JAVA based applications are also considered.

Poster MOPMN016 [0.986 MB]

WEBHMUST02

Solid State Direct Drive RF Linac: Control System

controls, experiment, software, LLRF

638

T. Kluge, M. Back, U. Hagen, O. Heid, M. Hergt, T.J.S. Hughes, R. Irsigler, J. Sirtl
Siemens AG, Erlangen, Germany
R. Fleck
Siemens AG, Corporate Technology, CT T DE HW 4, Erlangen, Germany
H.-C. Schröder
ASTRUM IT GmbH, Erlangen, Germany

Recently a Solid State Direct Drive ® concept for RF linacs has been introduced [1]. This new approach integrates the RF source, comprised of multiple Silicon Carbide (SiC) solid state Rf-modules [2], directly onto the cavity. Such an approach introduces new challenges for the control of such machines namely the non-linear behavior of the solid state RF-modules and the direct coupling of the RF-modules onto the cavity. In this paper we discuss further results of the experimental program [3,4] to integrate and control 64 RF-modules onto a λ/4 cavity. The next stage of experiments aims on gaining better feed forward control of the system and on detailed system identification. For this purpose a digital control board comprising of a Virtex 6 FPGA, high speed DACs/ADCs and trigger I/O is developed and integrated into the experiment and used to control the system. The design of the board is consequently digital aiming at direct processing of the signals. Power control within the cavity is achieved by an outphasing control of two groups of the RF-modules. This allows a power control without degradation of RF-module efficiency.
[1] Heid O., Hughes T., THPD002, IPAC10, Kyoto, Japan
[2] Irsigler R. et al, 3B-9, PPC11, Chicago IL, USA
[3] Heid O., Hughes T., THP068, LINAC10, Tsukuba, Japan
[4] Heid O., Hughes T., MOPD42, HB2010, Morschach, Switzerland

Slides WEBHMUST02 [1.201 MB]

WEPKS010

Architecture Design of the Application Software for the Low-Level RF Control System of the Free-Electron Laser at Hamburg

LLRF, controls, software, interface

798

Z. Geng
SLAC, Menlo Park, California, USA
V. Ayvazyan
DESY, Hamburg, Germany
S. Simrock
ITER Organization, St. Paul lez Durance, France

The superconducting linear accelerator of the Free-Electron Laser at Hamburg (FLASH) provides high performance electron beams to the lasing system to generate synchrotron radiation to various users. The Low-Level RF (LLRF) system is used to maintain the beam stabilities by stabilizing the RF field in the superconducting cavities with feedback and feed forward algorithms. The LLRF applications are sets of software to perform RF system model identification, control parameters optimization, exception detection and handling, so as to improve the precision, robustness and operability of the LLRF system. In order to implement the LLRF applications in the hardware with multiple distributed processors, an optimized architecture of the software is required for good understandability, maintainability and extendibility. This paper presents the design of the LLRF application software architecture based on the software engineering approach and the implementation at FLASH.

Poster WEPKS010 [0.307 MB]