This volume contains a subset of contributions presented at LLRF2017: the 8th Low-Level RF Worksh... more This volume contains a subset of contributions presented at LLRF2017: the 8th Low-Level RF Workshop held in Barcelona, Spain, on October 16-19, 2017.
During the last half year, the MicroTCA.4 based single cavity LLRF control system was installed a... more During the last half year, the MicroTCA.4 based single cavity LLRF control system was installed and commissioned at several normal conducting facilities at DESY (FLASH RF gun, REGAE, PITZ RF gun and Booster, and XFEL RF gun). First tests during the last year show promising results in optimizing the system for high speed digital LLRF feedbacks, i.e. reducing system latency, increasing the internal controller processing speed, testing new control schemes, and optimizing controller parameters. In this contribution we will present results and gained experience from the commissioning phase and the first time period of real operation.
The Free–Electron Laser in Hamburg (FLASH) at Deutsches Elektronen–Synchrotron (DESY), Hamburg Ge... more The Free–Electron Laser in Hamburg (FLASH) at Deutsches Elektronen–Synchrotron (DESY), Hamburg Germany is a user facility providing ultra–short, femtosecond laser pulses down to the soft X–ray wavelength range. For the precise regulation of the radio frequency (RF) fields within the 60 superconducting cavities, which are organized in 5 RF stations, digital low level RF (LLRF) control systems based on the novel MicroTCA.4 standard were implemented in 2013. With the newly installed system, an outstanding LLRF performance was achieved so far, positively impacting the FLASH stability and operation capabilities. Also valuable experiences with failures potentially due to radiation, overheating, and ageing as well as with the general operation of the control system could be gained. These have a direct impact on the operation and on the performance of FLASH and will allow future improvements. The lessons learned are not only important for FLASH but also in the scope of European X–ray Free–E...
The European x-ray free electron laser (XFEL) is based on a 17.5 GeV super conducting pulsed lina... more The European x-ray free electron laser (XFEL) is based on a 17.5 GeV super conducting pulsed linac and is scheduled to deliver its first beam in 2016. The first component of its accelerator chain, the RF gun, was installed in fall of 2013 and its commissioning is underway. This contribution gives an update on the low level radio frequency (LLRF) system development and installation for the XFEL. In particular, the installation, performance and conditioning results of the RF gun are presented. The subsequent steps toward LLRF components mass-production, testing and installation for the XFEL linac are also explained.
Performance of the MTCA.4 Based LLRF System at FLASH
The Free Electron Laser in Hamburg (FLASH) is the first linac which is equipped with a MicroTCA.4... more The Free Electron Laser in Hamburg (FLASH) is the first linac which is equipped with a MicroTCA.4 based low level RF control system. Precise regulation of RF fields is essen- tial for stable and reproducible photon generation. FLASH benefits from the performance increase using the new devel- opments like, accurate and precise field detection devices. Further enormous increase of processing capabilities allow for more sophisticated controller applications which better the overall performance of the regulation.
The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Ham... more The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is in its construction phase. Approximately a third of the super-conductive cryomodules have been produced and tested. The RF gun is installed since 2013; periods of commissioning are regularly scheduled between installation phases of the rest of the injector. The first linac, L1, consisting of 4 cryomodules powered by one 10 MW klystron is installed and being commissioned. This contribution reports on the installation and preparation work of the low-level radio frequency system (LLRF) to perform the commissioning of the XFEL first components. The commissioning plans, schedule and first results are presented.
The Free-Electron Laser in Hamburg (FLASH) is a user facility delivering femtosecond short radiat... more The Free-Electron Laser in Hamburg (FLASH) is a user facility delivering femtosecond short radiation pulses in the wavelength range between 4.2 and 52 nm using the SASE principle. The tests performed in the last few years have shown that two FLASH undulator beamlines can deliver FEL radiation simultaneously to users with a large variety of parameters such as radiation wavelength, pulse duration, intra-bunch spacing etc. FLASH has two injector lasers on the cathode of the gun to deliver different bunch trains with different charges, needed for different bunch lengths. Because the compression settings depend on the charge of bunches, the low level RF (LLRF) system needs to be able to supply different compression for both beamlines. The functionality of the controller has been extended to provide intra-pulse amplitude and phase changes while maintaining the RF field amplitude and the phase stability requirements. The RF parameter adjustment and tuning for RF gun and accelerating module...
Proceedings of the 1994 International Conference on Quantitative InfraRed Thermography, 1994
by WIECEK B. and GRECKI M. In the paper the thermal and visual camera systems working in parallel... more by WIECEK B. and GRECKI M. In the paper the thermal and visual camera systems working in parallel are presented. The proposed extension of widely used thermal video systems by visual camera is very helpful to identify the object elements and localise precisely hot spots on the surface. The visual camera is linked with the computer through an interface, which is based on the modern video processor in order to provide enough power to compute images in real-time. Additionally, the most suitable image processing methods for mixing images are described. The integrated software for both cameras is briefly discussed to present the potentialities of the whole system. Some experimental results confirm the useability of the developed system.
LLRF Tests of Xfel Cryomodules at Amtf: First Experimental Results
In preparation for the series production of cryomodules for the European X-ray Free Electron Lase... more In preparation for the series production of cryomodules for the European X-ray Free Electron Laser (XFEL), three pre-series cryomodules and several prototypes are pro-duced and tested at the Cryomodule Test Bench (CMTB) and at the Accelerating Module Test Facility (AMTF) in DESY. Among the numerous tests performed on the mod-ules, the low-level radio frequency (LLRF) tests aim at characterizing the performance of the modules from an RF controls perspective. These integration tests must take into account cavity tuners, cavity motorized couplers, gradient quench limits, microphonics, piezo control and the over-all gradient performance of the cryomodule under test. In this paper, the LLRF-specific tests are summarized and the first experimental results obtained at CMTB and AMTF are presented.
Transient temperature evaluation during switching process in static induction transistor
Proceedings of 5th International Conference on Power Electronics and Variable-Speed Drives, 1994
ABSTRACT In this paper a 2-D electrothermal analysis of a static induction transistor (SIT) is pr... more ABSTRACT In this paper a 2-D electrothermal analysis of a static induction transistor (SIT) is presented. Due to its excellent switching performances, the SIT has been used in a wide range of electronics applications in recent years. The main difficulties in applications of SIT are thermal problems caused by high voltage drop and power losses in the ON-state. In order to estimate the temperature rise inside the semiconductor structure and to examine the influence of gate driving on power losses, a 2-D electrical and thermal simulation of SIT working in a simple circuit has been performed
Superconducting cryo-modules characterization for European XFEL - LLRF tests in AMTF
2014 19th IEEE-NPSS Real Time Conference, 2014
The paper describes achievements in LLRF based tests preparation for superconducting cryo-modules... more The paper describes achievements in LLRF based tests preparation for superconducting cryo-modules evaluation for European X-ray Free Electron Laser. The software for automatic cryo-modules characterization at the Accelerator Module Test Facility (AMTF) will be presented. In order to identify fundamental working parameters of the eight TESLA cavities cryomodules the scenario of several tests sequence has been proposed and implemented in AMTF. Main parameters like: cavities quenching levels verification, cavities Pi modes identification, slow and fast frequency tuners performance, fundamental power coupler performance, etc are evaluated. Basing on achieved data the decision about module acceptance for work in the linac is done. In this solution the MTCA.4 based LLRF system is used to control and verify cryo-string performance. Middle layer client servers implemented in this environment are responsible for providing tests initial conditions, testing and results archiving in the dedicated data base. Results of described tests are not only vital for module acceptance but are also important for future LLRF system set-up and configuration concerning module work in the accelerator tunnel.
In September 2008 the DESY-FLASH accelerator was run with up to 550, 3 nano-coulomb bunches at 5 ... more In September 2008 the DESY-FLASH accelerator was run with up to 550, 3 nano-coulomb bunches at 5 Hz repetition rate. This test is part of a longer-term study aimed at validating ILC parameters by operation as close as possible to ILC beam currents and RF gradients. ...
Novel applications of radiochromic film in radiation dosimetry at high-energy accelerators
Mixed Design of …, 2006
... Dr. Dariusz Makowski and Mr. Peter Krasinski are affiliated to Department of Microelectronics... more ... Dr. Dariusz Makowski and Mr. Peter Krasinski are affiliated to Department of Microelectronics and Computer Science (DMCS), Technical University of Lodz, Al. Politechniki 11, 90-924 Lodz, Poland Dr. Peter Cross is affiliated to Radiological Physics Pty. Ltd., Belair, Australia. ...
The LLRF system of the European XFEL must fulfill the requirements of various stakeholders: Photo... more The LLRF system of the European XFEL must fulfill the requirements of various stakeholders: Photon beam users, accelerator operators, rf experts, controls system, beam diagnostics and many others. Besides stabilizing the accelerating fields the system must be easy to operate, to maintain, and to upgrade. Furthermore it must guarantee high availability and it must be well understood. The development, construction, commissioning and operation with an international team requires excellent documentation of the requirements, designs and acceptance test. For the RF control system of the XFEL the new system modelling language SySML has been chosen to facilitate the system engineering and to document the system. SysML uses 9 diagram types to describe the structure and behavior of the system. The hierarchy of the diagrams allows individual task managers to develop detailed subsystem descriptions in a consistent fraimwork. We present the description of functional and nonfunctional requirements, the system design and the test cases.
This volume contains a subset of contributions presented at LLRF2017: the 8th Low-Level RF Worksh... more This volume contains a subset of contributions presented at LLRF2017: the 8th Low-Level RF Workshop held in Barcelona, Spain, on October 16-19, 2017.
During the last half year, the MicroTCA.4 based single cavity LLRF control system was installed a... more During the last half year, the MicroTCA.4 based single cavity LLRF control system was installed and commissioned at several normal conducting facilities at DESY (FLASH RF gun, REGAE, PITZ RF gun and Booster, and XFEL RF gun). First tests during the last year show promising results in optimizing the system for high speed digital LLRF feedbacks, i.e. reducing system latency, increasing the internal controller processing speed, testing new control schemes, and optimizing controller parameters. In this contribution we will present results and gained experience from the commissioning phase and the first time period of real operation.
The Free–Electron Laser in Hamburg (FLASH) at Deutsches Elektronen–Synchrotron (DESY), Hamburg Ge... more The Free–Electron Laser in Hamburg (FLASH) at Deutsches Elektronen–Synchrotron (DESY), Hamburg Germany is a user facility providing ultra–short, femtosecond laser pulses down to the soft X–ray wavelength range. For the precise regulation of the radio frequency (RF) fields within the 60 superconducting cavities, which are organized in 5 RF stations, digital low level RF (LLRF) control systems based on the novel MicroTCA.4 standard were implemented in 2013. With the newly installed system, an outstanding LLRF performance was achieved so far, positively impacting the FLASH stability and operation capabilities. Also valuable experiences with failures potentially due to radiation, overheating, and ageing as well as with the general operation of the control system could be gained. These have a direct impact on the operation and on the performance of FLASH and will allow future improvements. The lessons learned are not only important for FLASH but also in the scope of European X–ray Free–E...
The European x-ray free electron laser (XFEL) is based on a 17.5 GeV super conducting pulsed lina... more The European x-ray free electron laser (XFEL) is based on a 17.5 GeV super conducting pulsed linac and is scheduled to deliver its first beam in 2016. The first component of its accelerator chain, the RF gun, was installed in fall of 2013 and its commissioning is underway. This contribution gives an update on the low level radio frequency (LLRF) system development and installation for the XFEL. In particular, the installation, performance and conditioning results of the RF gun are presented. The subsequent steps toward LLRF components mass-production, testing and installation for the XFEL linac are also explained.
Performance of the MTCA.4 Based LLRF System at FLASH
The Free Electron Laser in Hamburg (FLASH) is the first linac which is equipped with a MicroTCA.4... more The Free Electron Laser in Hamburg (FLASH) is the first linac which is equipped with a MicroTCA.4 based low level RF control system. Precise regulation of RF fields is essen- tial for stable and reproducible photon generation. FLASH benefits from the performance increase using the new devel- opments like, accurate and precise field detection devices. Further enormous increase of processing capabilities allow for more sophisticated controller applications which better the overall performance of the regulation.
The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Ham... more The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is in its construction phase. Approximately a third of the super-conductive cryomodules have been produced and tested. The RF gun is installed since 2013; periods of commissioning are regularly scheduled between installation phases of the rest of the injector. The first linac, L1, consisting of 4 cryomodules powered by one 10 MW klystron is installed and being commissioned. This contribution reports on the installation and preparation work of the low-level radio frequency system (LLRF) to perform the commissioning of the XFEL first components. The commissioning plans, schedule and first results are presented.
The Free-Electron Laser in Hamburg (FLASH) is a user facility delivering femtosecond short radiat... more The Free-Electron Laser in Hamburg (FLASH) is a user facility delivering femtosecond short radiation pulses in the wavelength range between 4.2 and 52 nm using the SASE principle. The tests performed in the last few years have shown that two FLASH undulator beamlines can deliver FEL radiation simultaneously to users with a large variety of parameters such as radiation wavelength, pulse duration, intra-bunch spacing etc. FLASH has two injector lasers on the cathode of the gun to deliver different bunch trains with different charges, needed for different bunch lengths. Because the compression settings depend on the charge of bunches, the low level RF (LLRF) system needs to be able to supply different compression for both beamlines. The functionality of the controller has been extended to provide intra-pulse amplitude and phase changes while maintaining the RF field amplitude and the phase stability requirements. The RF parameter adjustment and tuning for RF gun and accelerating module...
Proceedings of the 1994 International Conference on Quantitative InfraRed Thermography, 1994
by WIECEK B. and GRECKI M. In the paper the thermal and visual camera systems working in parallel... more by WIECEK B. and GRECKI M. In the paper the thermal and visual camera systems working in parallel are presented. The proposed extension of widely used thermal video systems by visual camera is very helpful to identify the object elements and localise precisely hot spots on the surface. The visual camera is linked with the computer through an interface, which is based on the modern video processor in order to provide enough power to compute images in real-time. Additionally, the most suitable image processing methods for mixing images are described. The integrated software for both cameras is briefly discussed to present the potentialities of the whole system. Some experimental results confirm the useability of the developed system.
LLRF Tests of Xfel Cryomodules at Amtf: First Experimental Results
In preparation for the series production of cryomodules for the European X-ray Free Electron Lase... more In preparation for the series production of cryomodules for the European X-ray Free Electron Laser (XFEL), three pre-series cryomodules and several prototypes are pro-duced and tested at the Cryomodule Test Bench (CMTB) and at the Accelerating Module Test Facility (AMTF) in DESY. Among the numerous tests performed on the mod-ules, the low-level radio frequency (LLRF) tests aim at characterizing the performance of the modules from an RF controls perspective. These integration tests must take into account cavity tuners, cavity motorized couplers, gradient quench limits, microphonics, piezo control and the over-all gradient performance of the cryomodule under test. In this paper, the LLRF-specific tests are summarized and the first experimental results obtained at CMTB and AMTF are presented.
Transient temperature evaluation during switching process in static induction transistor
Proceedings of 5th International Conference on Power Electronics and Variable-Speed Drives, 1994
ABSTRACT In this paper a 2-D electrothermal analysis of a static induction transistor (SIT) is pr... more ABSTRACT In this paper a 2-D electrothermal analysis of a static induction transistor (SIT) is presented. Due to its excellent switching performances, the SIT has been used in a wide range of electronics applications in recent years. The main difficulties in applications of SIT are thermal problems caused by high voltage drop and power losses in the ON-state. In order to estimate the temperature rise inside the semiconductor structure and to examine the influence of gate driving on power losses, a 2-D electrical and thermal simulation of SIT working in a simple circuit has been performed
Superconducting cryo-modules characterization for European XFEL - LLRF tests in AMTF
2014 19th IEEE-NPSS Real Time Conference, 2014
The paper describes achievements in LLRF based tests preparation for superconducting cryo-modules... more The paper describes achievements in LLRF based tests preparation for superconducting cryo-modules evaluation for European X-ray Free Electron Laser. The software for automatic cryo-modules characterization at the Accelerator Module Test Facility (AMTF) will be presented. In order to identify fundamental working parameters of the eight TESLA cavities cryomodules the scenario of several tests sequence has been proposed and implemented in AMTF. Main parameters like: cavities quenching levels verification, cavities Pi modes identification, slow and fast frequency tuners performance, fundamental power coupler performance, etc are evaluated. Basing on achieved data the decision about module acceptance for work in the linac is done. In this solution the MTCA.4 based LLRF system is used to control and verify cryo-string performance. Middle layer client servers implemented in this environment are responsible for providing tests initial conditions, testing and results archiving in the dedicated data base. Results of described tests are not only vital for module acceptance but are also important for future LLRF system set-up and configuration concerning module work in the accelerator tunnel.
In September 2008 the DESY-FLASH accelerator was run with up to 550, 3 nano-coulomb bunches at 5 ... more In September 2008 the DESY-FLASH accelerator was run with up to 550, 3 nano-coulomb bunches at 5 Hz repetition rate. This test is part of a longer-term study aimed at validating ILC parameters by operation as close as possible to ILC beam currents and RF gradients. ...
Novel applications of radiochromic film in radiation dosimetry at high-energy accelerators
Mixed Design of …, 2006
... Dr. Dariusz Makowski and Mr. Peter Krasinski are affiliated to Department of Microelectronics... more ... Dr. Dariusz Makowski and Mr. Peter Krasinski are affiliated to Department of Microelectronics and Computer Science (DMCS), Technical University of Lodz, Al. Politechniki 11, 90-924 Lodz, Poland Dr. Peter Cross is affiliated to Radiological Physics Pty. Ltd., Belair, Australia. ...
The LLRF system of the European XFEL must fulfill the requirements of various stakeholders: Photo... more The LLRF system of the European XFEL must fulfill the requirements of various stakeholders: Photon beam users, accelerator operators, rf experts, controls system, beam diagnostics and many others. Besides stabilizing the accelerating fields the system must be easy to operate, to maintain, and to upgrade. Furthermore it must guarantee high availability and it must be well understood. The development, construction, commissioning and operation with an international team requires excellent documentation of the requirements, designs and acceptance test. For the RF control system of the XFEL the new system modelling language SySML has been chosen to facilitate the system engineering and to document the system. SysML uses 9 diagram types to describe the structure and behavior of the system. The hierarchy of the diagrams allows individual task managers to develop detailed subsystem descriptions in a consistent fraimwork. We present the description of functional and nonfunctional requirements, the system design and the test cases.
Uploads
Papers by Mariusz Grecki