Book Autumn edition 2016

Transcription

1 Book Autumn edition 2016

2 Libera references Asia HiSOR (Japan) IBS RISP (Korea) IHEP BEPC II, ADS (China) IMP-CAS ADS (China) IMS UVSOR (China) ISSP (Japan) JASRI SPring-8 (Japan) KEK PF, PF AR, LINAC, SUPER B, J-LAB (Japan) KIRAMS Khima (Japan) Nagoya University Chubu Synchrotron (Japan) NSRRC TLS, TPS (Taiwan) PAL PLS II, XFEL ITF (Korea) Peking University (China) RRCAT INDUS, INDUS II (India) SINAP SSRF (China) SLRI (Thailand) SJTU (China) Tsinghua University (China) USTC, NSRL HLS, HLSII (China) Australia Australian Synchrotron (Australia) Europe ADAM SA (Switzerland) CANDLE (Armenia) CELLS ALBA (Spain) CERN (Switzerland) Danfysik S/A (Denmark) DELTA (Germany) DESY PETRA III, FLASH, DESY XFEL, DORIS III (Germany) DIAMOND Light Source (United Kingdom) ESRF (France) Forschungszentrum Juelich (Germany) Fritz Haber Institute of the MPS (Germany) FZK ANKA (Germany) GANIL (France) GSI SIS 18 (Germany) Helmholtz-Zentrum Berlin BESSY II (Germany) Helmholtz-Zentrum Dresden-Rossendorf (Germany) IJS (Slovenia) INFN Daphne, ELI-NP (Italy) IPNO (France) ISA ASTRID II (Denmark) Jagiellonian University SOLARIS (Poland) LAL THOM-X (France) Lund University MAX III, MAX IV (Sweden) MPG (Germany) Physics Institute of the University of Bonn (Germany) PSI SLS, SwissFEL (Switzerland) RRC Kurchatov Institute SIBERIA II (Russia) SDU TARLA (Turkey) SESAME (Jordan) Sincrotrone Trieste Elettra (Italy) SOLEIL Synchrotron (France) STFC ASTeC EMMA (United Kingdom) University of Twente (Netherland) North America ANL APS (United States) BNL ERL, NSLS II, RAY ring (United States) Canadian Light Source, CLS (Canada) Cornell University CHESS (United States) LANL LANSCE (United States) LBNL ALS (United States) Michigan State University FRIB (United States) Northwestern University (United States) SLAC LCLS (United States) South America ABTLuS LNLS (Brazil)

3 The accelerator community knows us as Libera folks. Apparently has the story that started back in 2003 left some marks. Nevertheless, 9 out of 10 synchrotron light sources around the world have been equipped with our Libera beam position stabilization systems. But Libera is much more than just the sum of its products. It means the best possible performance for the price. It means innovation, quality and reliability. It means long-term support. However it is the relationships we have nurtured over the years with our customers that we cherish most. Libera products seamlessly combine hardware and software into powerful instruments that measure a variety of beam parameters. Those measurements are then used in feedback loops to optimize the performance of a particle accelerator. Different accelerators have different needs. However, through the re-configurability and modularity of Libera instruments we can accommodate a variety of end-user requirements. Libera instruments are developed and manufactured by the Instrumentation Technologies company. Established in 1998 the business has grown from a garage-based start-up to an established company known for Libera and Red Pitaya products and for launching the Centre of Excellence for Biosensors, Instrumentation and Process Control (COBIK). Rok Uršič Chief Executive Officer

4 Table of Contents BPM Electronics 5 Digital LLRF 14 Clock Transfer System 18 Reference Master Oscillator 21 Beam Loss Monitor 22 Digitizer 25 Your Idea 26 Software 27 Extensions 28 Services and support 30 Instrumentation Technologies 4

5 BPM Electronics Libera beam position monitor electronics feature high resolution position measurement of the beam (electrons, protons, ions, photons, etc.). Their digital signal processing supports programmable bandwidth and can facilitate position measurement in various regimes: pulsed, single bunch pulsed, micro/macro pulse bunch-by-bunch turn-by-turn first-turn measurement closed loop (fast, slow) Beam position monitors are optimized for the beam type. They are categorised as follows: Electron Hadron Photon Libera Brilliance+ Libera Single Pass E Libera Cavity BPM Libera Hadron Libera Single Pass H Libera Photon The closed loop operation can be further expanded with extension modules that enable global orbit feedback capability. These modules fit inside the instruments and provide fast serial communication links (optical, copper), GbE and RS-485 interfaces. These interfaces can be used to control the corrector magnets and/or pre-amplifiers. Typically the beam position is measured with sub-micron resolution. Signal processing The electrical signals generated by the BPM pickups are acquired and processed by the instrument analog front-end. Depending on the BPM signal characteristics, the front-end can perform analog signal filtering, down-conversion, amplification and attenuation. Different BPM pickup types are supported: button, stripline, cavity, shoebox, etc. If phase measurement is required (for heavy-ion LINACs), the fifth channel represents the reference signal. The beam position monitor for the photon beams receives the current signals from detectors and does the current-to-voltage conversion in its front-end. Calibration and digital signal processing are specific to the instrument version and its application. The most advanced beam position monitor for electron beams combines the cross-bar switch with the algorithm that identifies the channel-to-channel differences and applies the corrections in real time. Other calibration mechanisms usually allow users to manage correction schemes. The front-end of the photon beam position monitor contains a connector that receives the BIAS voltage which is then applied to all four input channels. Instrumentation Technologies 5

6 Figure 1 shows how the input signals are processed until the raw A/D stream is available at the read-out buffer. Front-end Figure 1: Signal processing from electrical signals to stream of A/D data Once the A/D data is available, it is stored in a read-out buffer and further processed. Processing paths are specific to the instrument type and provide the data (amplitudes, position, phase) at different data rates and bandwidths. For linear accelerators and energy recovery LINACs, the digital signal processing outputs data for any beam flavor: a single bunch, a train of bunches (macro pulse) or it can provide a continuous data stream with a chosen averaging factor for a continuous beam. The application for heavy ions also outputs the phase information. In combination with the optical event-based timing system, it is possible to apply specific signal treatment (e.g. attenuation set, beam mark) to a specific macropulse or bunch (Figure 2). Figure 2: Signal processing for linear accelerators and energy recovery LINACs For electron accelerator applications on which very high beam position resolution is required (FELs, Compton back scattering, etc.), cavity-type pickups are often used. In this case the Libera Cavity BPM system acquires and processes three input signals: reference, X and Y cavity signals. Depending on the resonant frequency of the cavities (e.g. S-band, C-band), the signals are downconverted, filtered and adjusted to be digitized with 500MS/s ADCs and later stored in a databuffer. The variable attenuators present in the instrument front-end enable the user to optimize the acquired signal level depending on the beam charge. Once the data is digitized, the instrument features the position calculation with a time-domain processing algorithm. If the machine operates in single-bunch mode, the useful bunch signal is separated from the noise and one position is calculated. In the case of bunch-train operation Instrumentation Technologies 6

7 mode, if the cavity quality factor (Q) is low and the spacing between the bunches is large enough, it is possible to process the signal produced by each bunch independently and to obtain a position for each bunch, still with sub-micrometer resolution. The stored beam in synchrotrons is processed on a bunch-to-bunch or turn-by-turn basis (wideband data). Several processing options are specified by the type of digital signal processing that is specific to the instrument version. Turn-by-turn processing is performed in frequency or in time domain. Post-processing typically includes on-demand Fast Fourier Transformation (FFT) as well as a calculation of the average, minimum, maximum, mean and RMS values. The wide-band data is decimated and filtered in two steps that reduce the data rate and bandwidth. The Fast data is used for global orbit feedback applications (fast rate) and slow orbit monitoring (slow rate) (Figure 3). Bunch-by-bunch Figure 3: Digital signal processing for stored beams Photon beams are processed by a processing chain that can be customized for averaging, data rate and filtering parameters. Position can be provided at turn-by-turn data rate if the turn-by-turn frequency is lower than 2.5 MHz (other conditions also apply). The Fast and Slow data streams are filtered through an IIR filter and a decimation block (Figure 4). Figure 4: Digital signal processing for photon beams Instrumentation Technologies 7

8 Instruments Beam position monitors are available in three form factors. The larger version (2U, 19 ) hosts up to four BPM modules and several extensions for the orbit feedback systems and timing systems (Figure 5). BPM modules CPU module GDX module Timing module Figure 5: 2U, 19 Beam position monitor The smaller version (1U, 9.5 ) or extended (1U,19 ) is supporting 1 BPM pickup. Due to its compact dimensions and Powered over Ethernet (PoE) compatibility, it can be installed in the tunnel close to the BPM pickup in an appropriate (radiation protected) location (Figure 6). Memory slot for µsd card USB console Ethernet interface USB RF input channels Timing signals Figure 6: 1U, 9.5 Beam position monitor The photon beam position monitor contains a second RJ-45 interface that is used to output the Fast data stream and a USB port. TRIAX connectors are used for input channels (Figure 7). Memory slot for µsd card USB RF input channels Timing signals Fast data output USB console Ethernet interface External BIAS input Figure 7: 1U, 9.5 Photon beam position monitor Instrumentation Technologies 8

9 Electron Beam Position Monitors The hardware capabilities, functionalities and performance specifications of the electron beam position monitors are summarized in Tables 1, 2 and 3. The instruments are generally built on two platforms, each of them offering specific advantages. Table 1: Hardware capabilities of Electron beam position monitors for CIRCULAR machines for LINEAR machines Electron BPMs capabilities ER ERXR Libera Brilliance+ EL Libera Single Pass E BPM slots Libera Cavity BPM Extension slots / 2 / 2 / Dimensions (H W D) mm (483) (483) (483) 210 A/D conversion 125 MHz/14 bit 130 MHz/16 bit 125 MHz/14 bit 160 MHz/16 bit 500 MHz/14 bit ADC sampling clock control FPGA/CPU Manual set, free running Manual set, PLL Zynq-7020, ARM Cortex-A9 PLL Virtex 5 & 6, COMe module Manual set, free running Zynq-7020, ARM Cortex-A9 Manual set, free running Virtex 5 & 6, COMe module PLL Zynq-7035, ARM Cortex-A9 Operating System Linux Linux Ubuntu Linux Linux Ubuntu Linux Cooling Passive Active (fans) Passive Active (fans) Passive Power supply PoE 110/220 V, 250 W PoE 110/220 V, 250 W PoE ** Timing signals Electrical (up to 3) Calibration / SFP support / Maximum input signal* Input gain/attenuation < -40 dbm continuous Fixed * Can be customized ** Information available by the end of 2016 < -10 dbm continuous Programmable, 31 db Electrical (4)/ Optical Crossbar switch, DSC 4 (6.5 Gbps) with GDX module < +4 dbm continuous Programmable, 31 db, automatic mode Electrical (up to 3) Manual gain correction / < 5 V peak pulse voltage Programmable, 31 db Electrical (4)/ Optical Manual gain correction 4 (6.5 Gbps) with GDX module < 7 V peak pulse voltage Programmable, 31 db Electrical (up to 3) Manual gain correction / ** Programmable, 31 db Instrumentation Technologies 9

10 Table 2: List of functionalities of the Electron beam position monitors for CIRCULAR machines for LINEAR machines Electron BPMs functionalities ER ERXR Libera Brilliance+ EL Libera Single Pass E Libera Cavity BPM Bunch-by-bunch processing No* No* Yes Yes Yes Turn-by-turn processing Yes (triggered) Yes (continuous) No No No Fast data No Yes No Yes No Slow data No Yes Yes No No No Gain control No Yes Yes (continuous) Yes Yes Yes Selectable processing window Yes Yes Yes Yes Yes Processing delay No Yes Yes Yes Yes Multi-chassis synchronization Data time stamping Trigger-based Trigger-counter Reference clock with PLL Reference clock with PLL and State machine Yes, various (turn, trigger, sampling clock) Trigger-based Trigger-based Trigger-based Trigger-counter Trigger-counter Trigger-counter Interlock detection and output No Yes No Yes No Postmortem capability No Yes No No No Statistics and FFT No Yes No No No Single-pass measurement No Yes Yes Yes Yes * Only in single bunch single turn measurements Table 3: Measurement performance for stored beam applications and for linear accelerators and energy recovery LINACs applications Electron BPMs performance specifications for CIRCULAR machines for LINEAR machines ER ERXR Libera Brilliance+ EL Libera Single Pass E Libera Cavity BPM Temperature drift, typical 2 µm/ C 0.2 µm/ C 0.3µm/ C 0.3µm/ C ** Position RMS at turn-by-turn data rate Position RMS at fast data rate (0-2 khz bandwidth) Position RMS at slow data rate (0-4 Hz bandwidth) 5 µm 1 µm 0.5 µm / / / / 0.07 µm / / / / < 0.5 µm 0.02 µm / / / Position RMS at single bunch / / 4 µm 1 µm < 1 µm Position RMS at macro pulse/ continuous wave / / < 4 µm < 1 µm / ** Information available by the end of 2016 Instrumentation Technologies 10

11 Hadron Beam Position Monitors The capabilities, functionalities and measurement performance of the beam position monitors depend on the instrument s hardware platform (Tables 4, 5 and 6). Table 4: Hardware capabilities of Hadron beam position monitors for CIRCULAR machines for LINEAR machines Hadron BPMs capatibilities HR Libera Hadron HL Libera Single Pass H BPM slots Extension slots / 2 / 2 Dimensions (H W D) mm (483) (483) 310 A/D conversion 125 MHz/14 bit 250 MHz/16 bit 125 MHz/14 bit 130 MHz/16 bit HADC sampling clock control Manual set, free running PLL Manual set, free running Manual set, free running FPGA/CPU Zynq-7020, ARM Cortex-A9 Virtex 6, COMe module Zynq-7020, ARM Cortex-A9 Virtex 5 & 6, COMe module Operating System Linux Linux Ubuntu Linux Linux Ubuntu Cooling Passive Active (fans) Passive Active (fans) Power supply PoE 110/220 V, 250 W PoE 110/220 V, 250 W Timing signals Electrical (up to 3) Electrical (4)/Optical Electrical (up to 3) Electrical (4)/Optical Calibration / / Manual gain correction / SFP support / 4 (6.5 Gbps) with GDX module / 4 (6.5 Gbps) with GDX module Maximum input signal * < 2 V peak pulse voltage < 2 V peak pulse voltage < +22 dbm +22 dbm Input gain/attenuation Fixed Fixed Programmable, 31 db Fixed * Can be customized Instrumentation Technologies 11

12 Table 5: List of functionalities of the Hadron beam position monitors for CIRCULAR machines for LINEAR machines Hadron BPMs functionalities HR Libera Hadron HL Libera Single Pass H Bunch-by-bunch processing Yes Yes No No Fast data No Yes No Yes Slow data No Yes No No Gain control No External amplifier module Yes No Selectable processing window Yes Yes Yes Yes Processing delay Yes Yes Yes Yes Multi-chassis synchronization Trigger-based Reference clock with PLL Trigger-based Trigger-based Data time stamping No Yes, external RF clock Trigger-counter Trigger-counter Interlock detection and output No No No Yes Postmortem capability No Yes No No Statistics and FFT No Yes No No Single-pass measurement Yes Yes Yes Yes Table 6: Measurement performance for stored beam applications and for linear accelerators and energy recovery LINACs applications Hadron BPMs performance specifications for CIRCULAR machines for LINEAR machines HR Libera Hadron HL Libera Single Pass H Temperature drift, typical * 2 µm/ C 0.3 µm/ C 0.5 µm/ C Position RMS at bunch-by-bunch data rate Position RMS at fast 10 khz data rate Position RMS at slow 10 Hz data rate Position RMS at 1 MHz data rate 10 µm ** 6 µm ** / / / < 1 µm ** / / / < 1 µm ** / / / / < 1 µm < 2 µm, < 0.01 * Not available yet ** K=100 mm Instrumentation Technologies 12

13 Photon Beam Position Monitor The hardware capabilities, functionalities and performance specifications of the photon beam position monitor are set out in Tables 7, 8 and 9. Table 7: Hardware capabilities of Photon beam position monitors Table 8: List of functionalities of the Photon beam position monitors Photon BPM capatibilities Photon BPM functionalities Libera Photon BPM slots 1 Extension slots / Dimensions (H W D) mm Bunch-by-bunch processing Turn-by-turn processing Fast data Libera Photon No Yes* Yes A/D conversion 2.5 MHz / 18 bit Slow data Yes ADC sampling clock control PLL Gain control Yes FPGA/CPU Zynq-7020, ARM Cortex-A9 Operating System Linux Cooling Passive Power supply PoE Timing signals Electrical (3) Calibration Manual SFP support / * Maximum input signal* 1.85 ma Input gain/attenuation Programmable * UDP stream over GbE available Selectable processing window Yes Processing delay Yes Multi-chassis synchronization Yes Data time stamping Yes, various Interlock detection and output No Postmortem capability Yes Statistics and FFT No Single-pass measurement No * Only for-turn-by-turn frequency lower than 1 MHz Table 9: Measurement performance for photon beams Photon BPM performance specifications Libera Photon Temperature drift, typical 0.01 µm / C 8-hour stability at (23 ± 1) C (range 200 µa) RMS ks/s data rate RMS ks/s data rate 0.02 µm < 0.02 µm < 0.01 µm Instrumentation Technologies 13

14 Digital LLRF The Libera LLRF is a digital processing and feedback system which monitors and stabilizes the quality of the beam acceleration by controlling the phase and amplitude of the RF field injected into the machine accelerating structures. Being designed to be modular and reconfigurable, the system can fit the exact requirements of any kind of accelerator, providing three core functions: Stabilization of the cavities RF field: depending on the RF signals acquired from the accelerating structures and the set-point specified by the user, the fast feedback loop controls the properties of the RF signal, which is later used to drive the Klystrons. Cavity tuning: by monitoring the forward and reflected signals from the RF cavities, the system can be interfaced to control slow and fast tuners (e.g. stepper motors and piezo controllers) which modify the cavity mechanical properties. Machine Diagnostics: the user is able to analyze all the signals digitized by the system, as well as the status of the feedback loop. Several signals can also be monitored by the system in order to generate Interlock events if something unexpected happens. The block-scheme presented in Figure 8 presents a possible configuration of Libera LLRF in the accelerator environment: Figure 8: A possible configuration of Libera LLRF in the accelerator environment Instrumentation Technologies 14

15 Interfaces and Signal Processing The Libera LLRF system is based on the MCTA.0 standard with several AMC boards connected to the chassis backplane (Figure 9). CPU module Vector modulator module ADC9 modules Timing module Figure 9: Digital Libera LLRF Up to four processing modules (ADC9) can be connected to the system in order to acquire up to 32 RF signals from the cavities; if fewer signals need to be acquired, the number of ADC9 modules can be reduced. The ADC9 modules are responsible for the analog signal processing of the input signals and their digitization with 130MS/16 bit A/D converters: this data is stored in the device memory and available to the user. The digitized signals are later transferred to the Vector Modulator board, where the feedback logic is actually implemented (see Figure 10). Figure 10: Signal processing in the Libera LLRF system Instrumentation Technologies 15

16 The phase rotation block is used to calibrate each different input signal in phase and amplitude; this is so that differences in RF cabling and delays resulting from the beam time of flight do not influence the calculation. The vector sum then combines all the acquired signals in one equivalent signal, which is used as the input for the control algorithm. In addition to the data digitized through the A/D converters, the user can also analyze the signals inside the feedback loop, either at the original rate or at decimated rate. One of the possible ways to monitor all this information is through the system Graphical User interface (GUI), as presented in Figure 11. Figure 11: Graphical User Interface (GUI) for the Libera LLRF Capabilities Table 10: Capabilities of the Libera LLRF system The capabilities of the Libera LLRF system are summarized in Table 10. RF input channels RF input frequency Maximum RF input power A/D conversion FPGA/CPU Operating System RF output channels Maximum RF output power Cooling Power supply Libera LLRF Up to 32 (8 per ADC9 module) Up to 12 GHz 20 dbm 130 MHz/16 bits Virtex 5, Intel i5 2.7GHz Linux Ubuntu 2 (1 RF drive, 1 calibration output) > 10 dbm Active (6 fans) 110/220 V Dimensions (H W D) mm (483) 310 Instrumentation Technologies 16

17 Functionalities The functionalities of the Libera LLRF system are summarized in Table 11. Table 11: Functionalities of the Libera LLRF system Functionality Machine Operation mode Fast-feedback loop Cavity tuning Signal monitoring and Diagnostics Machine Protection Temperature Compensation Description Continuous wave (CW) Pulsed Combined Gain Driven Resonator (GDR) and Self-Excited Loop (SEL) Intra-Pulse and Pulse-to-Pulse feedback Separate or combined loop (Amplitude and Phase, I & Q) Beam Loading compensation Compensation for Klystron non-idealities Compatible with variable RF frequency machines Extensible to multiple inputs from cavities driven by the same klystron Based on the cavity detune measurement algorithms: based on forward and reflected signals for CW machines, based on cavity voltage decay on pulsed machines. Slow tuning with PID controller and stepper motor driver interface. Fast tuning loop with piezo controller Possible to observe input signals and internal feedback signals Observe signals at A/D conversion rate (130 MHz) or decimated (1 Hz to 10 khz) Visualize signals on the Graphical User Interface Direct measurement of amplitude and phase Derived measurement of signal power and cavity resonant frequency RF system frequency response characterization Loop stability analysis (Nyquist stability criteria) Fast interlock interface (Input and Output) with active low logic Temperature stabilized RF front-end within separated chassis (Figure 12) Calibration output usable for RF cables and RF front-end electronics calibration Performance Specifications The main performance specifications of the Libera LLRF system are summarized in Table 12. The results were obtained at the DESY FLASH and Daresbury Laboratory EMMA at a 1 MHz BW pulsed mode of operation. Table 12: Performance Specifications of the Libera LLRF system Amplitude stability Phase stability Latency (Input Drive output) Long-term temperature stability with temperature stabilized RF front-end Libera LLRF < 0.01% RMS < 0.01 RMS Down to 250ns < 100fs / 72 hours Figure 12: Libera LLRF temperature stabilized RF front-end Instrumentation Technologies 17

18 Clock Transfer System The Libera Sync system is used to transmit high-quality clock signals from a source, usually a Reference Master Oscillator, to numerous systems that need to be synchronized along the machine (e.g. LLRF stations). It consists of a transmitter and a receiver connected to a pair of single-mode optical fibers (Figure 13). Interfaces and Signal Processing RF input: Reference clock signal input, connect to the +15dBm Reference Master Oscillator output, SMA interface. Two SC-APC optical interfaces on the rear panel. Service port used for firmware update, USB interface. Memory card: a standard memory card slot for local data logging. LED indicators: RUN: the system is operational LOCKED: the system is phase-locked ERROR: error indication such as insufficient temperature stabilization, RF signal out of range, etc. Transmitter 10/100Mb Ethernet port used for interconnection of the Transmitter and the Receiver unit and for remote control of the unit, RJ45 interface. LCD displays monitored system parameters, statuses and error messages. Rotary knob is used for moving through the menu items (rotation) and for selecting/editing the menu items (pressing the knob). Keyboard arrow keys are used for moving through the menu items. The HOME key selects the root menu while the ESC key selects the parent menu. In combination with the rotary knob, it is used for local system control. RF Output 1 provides transferred RF signal, SMA interface. RF Output 2 provides transferred RF signal, SMA interface. Two SC-APC optical interfaces on the rear panel. Receiver RF Monitoring Output provides transferred RF signal for monitoring purposes, SMA interface. Figure 13: Clock Transfer System (Libera Sync 3) Instrumentation Technologies 18

19 The transmitter input signal is a continuous wave RF reference signal which modulates an optical carrier through an electro-optical modulator. The modulated signal is split into two parts and fed into the two optical links: a low-drift link and a low-jitter link (see the block scheme in Figure 14). The low-drift signal is partially reflected at the receiver and used to perform phase drift compensations in the transmitter. At the receiver, the optical signals from both links are demodulated into the RF domain. The low jitter signal is amplified, filtered and stabilized in amplitude and phase using the low-jitter signal. This signal is used to provide two RF outputs and one monitoring output. Libera Sync 3 Transmitter optical path Libera Sync 3 Receiver Δφ Phase Detector & Controller Phase Detector & Controller Reference clock input Δφ Automatic level control Fiber drift compensation block LASER + EOM Low drift link Optical mirror Amplifier & filter Reference signal output Low jitter link Δφ Automatic level control Phase Detector & Controller control signal optical signal RF signal RF monitoring signal Optical RF phase compensation block photodiode Figure 14: Libera Sync 3 block scheme To achieve the required performance and stability over the long term, both transmitter and receiver are stabilized in temperature and humidity, and are mechanically robust. Once tuned, the system requires very low maintenance. Instrumentation Technologies 19

20 Capabilities There are two Libera Sync versions: Libera Sync 500 covers the carrier frequencies around 500 MHz, while Libera Sync 3 covers S-band frequencies (Table 13). Table 13: Capabilities of the clock transfer systems Libera Sync 500 Libera Sync 3 Carrier frequency ( ) MHz GHz or GHz RF inputs 1 1 RF input level (15 ± 3) dbm (15 ± 1) dbm RF outputs 2 2 RF output level (15 ± 0.2) dbm (15 ± 0.5) dbm Optical link length (maximum) 500 m 1500 m Optical fiber drift compensation range 500 ps 500 ps Dimensions 1U 19 standard 2U 19 standard Calibration and tuning mode Manual Automatic Operating temperature range ºC ºC Operating relative humidity range 0 80 % 0 80 % Performance Specifications The performance specifications of the clock transfer systems are summarized in Table 14, while Figure 15 presents the added jitter measurement and long-term stability for Libera Sync 3. Table 14: Performance Specifications of the clock transfer systems Added jitter 10 Hz to 10 MHz 24-hour drift Libera Sync 500 Libera Sync 3 30 fs typ. 50 fs max. 150 fs RMS typ. 500 fs RMS max. < 10 fs < 40 fs peak-to-peak typ. < 100 fs peak-to-peak max. 6 Added jitter relative to reference signal 80 Phase drift relative to input reference signal 5 40 Integrated jitter [fs] Phase drift [fs] Frequency [Hz] time [days] Figure 15: Added jitter and long-term phase stability measured with Libera Sync 3 Instrumentation Technologies 20

21 Reference Master Oscillator The Reference Master Oscillator (RMO) provides a 2856 MHz sine wave signal with low phase noise on four outputs with a maximum power of + 18 dbm per output. The device free-runs on an internal OCXO which can additionally be locked to an external 10 MHz reference signal. The oscillator has very good frequency stability when free-running on OCXO (+/- 0.3 ppm in range of temperature from 20 C to 40 C) combined with extremely low phase noise, below 30 fs in the range between 10 Hz and 10 MHz. The front and back panels of the instrument are shown in Figure 16. Front Power indicator LED PLL locked indicator LED 2856 MHz outputs (4x) Monitor Output Frequency set trimmer Output power set trimmer Back On switch Fuse drawer Power inlet Ground Terminal Heat Sink Reference input Toggle mode switch Figure 16: Front & back panel The RF specifications of Reference Master Oscillator are presented in Table 15. Table 15: RF specifications RMO Minimal settable power per output +13 dbm Maximal settable power per output +18 dbm Monitor output power (referenced to outputs) -20 db Output power stability 0.08 db/ C Amplitude balance between any two outputs < 0.3 db Return loss -20 db Lowest output frequency GHz Highest output frequency GHz Frequency stability (free-running mode) +/- 0.3 ppm Integrated phase noise (max) < 30 fs (10 Hz 10 MHz) Phase balance between any two outputs (typical) < 20 deg Phase drift between any two outputs (typical) 0.01 deg/ C Harmonic suppression < 55 dbc up to 5th harmonic PLL lock time < 60 s Instrumentation Technologies 21

22 Beam Loss Monitor The Libera BLM handles all types of losses, and measures them with a high level of detectability and high time resolution. In contrast to other BLM systems, the beam loss monitor from the Libera family detects the losses ranging from a single electron to the huge losses that usually occur during injection. Thanks to its high time resolution (8 ns), it provides detailed insight into sub-turn losses. This effectively makes it possible to detect and select only those losses which come from a part of the beam-fill pattern. Beam loss monitor can be provided in two configurations: Beam loss monitor electronics Beam loss monitor system (electronics + detector) Signal Processing The signal from the beam loss detector (usually the photo-multiplier tube) is typically a unipolar pulse or train of pulses with negative polarity. It is possible to detect huge losses and very small losses thanks to the switchable front-end s input impedance. The input signal is sampled at fixed ADC sampling clock. Each of the four channels is treated independently from the others. Figure 17 shows how the input signals are processed until the algorithms are applied to the raw A/D stream. Front-end Figure 17: Signal processing in the beam loss monitor Once the A/D data is available, it is stored in a read-out buffer. The ADC samples in each of the processing chains are summed over the user-defined number of ADC samples and stored to the SUM buffer. The data samples from the SUM buffer are additionally averaged and stored to the AVG buffer. The sequence of algorithms is presented in Figure 18. In addition to triggered data type, the stream waveform is output at the user-defined interval (e.g. 0.1 second). It provides the user with the classic count-mode data. Another data stream is derived from the SUM-buffer source data. The data rate is specified by the SA decimation parameter. Instrumentation Technologies 22

23 & Libera Book Autumn edition 2016 Figure 18: Algorithms in beam loss monitor Instruments The beam loss monitor system consists of the instrument and the detector. The instrument is packed into standard 1U, 9.5 housing and requires a PoE compliant Ethernet interface. Each of the four input channels provides PMTs with power supply and gain control (Figure 19). Figure 19: Beam loss monitor system (instrument + detector) Instrumentation Technologies 23

24 Capabilities The hardware capabilities of beam loss monitors are summarized in Table 16. Table 16 Hardware capabilities of the beam loss monitor and the photo-multiplier tube Libera BLM Beam Loss Detector (BLD) Input channels 4 Dimensions (H W D) mm A/D conversion ADC sampling clock control FPGA/CPU Operating System 125 MHz/14 bit Manual set, free running (no PLL) Zynq-7020, ARM Cortex-A9 Linux in Zynq Scintillator Rod for γ-ray detection Typical dimensions Length: 100 mm Diameter: ~22 mm Aluminum housing, ~2 mm Lead shielding Cooling Passive Photosensor (Hamamatsu ) Power supply Timing signals Measurement range Measurement Ω input impedance Matching impedance Output channels PoE Electrical trigger (1), 2 optional up to ± MΩ up to ±5 50 Ω ~35 MHz large signal bandwidth ~50 MHz small signal bandwidth 50 Ω/1 MΩ, selectable 4x power supply (up to ±15 V) 4x gain control (up to 12 V) Input voltage: (5±0.5) V Input current: 2.7 ma maximum Gain control voltage: 1.1 V maximum (at 1 MΩ) Rise time: 0.57 ns Dark current: 1 na (typical) Peak sensitivity wavelength: 400 nm Dimensions (H W D) mm: approximately Beam loss detector Dimensions (H W D) mm: approximately (without the fitting holder) Weight: approximately 150 g (without the Lead cover) Operating temperature: +10 C to +40 C Functionalities The functionalities of the beam loss monitor are summarized in Table 17. Table 17: Functionalities of the beam loss monitor Low loss detection Fast loss detection Synchronization with timing system Automatic loss detection Select input range Switchable input impedance Count mode Photosensor control Libera BLM Detecting volumes as low as a single electron loss using high input impedance Sub-turn loss detection. Typically used during injection Electrical trigger Adjustable threshold, auto buffer filling 31 db programmable attenuator Software selectable: 50 Ω/1 MΩ Adjustable threshold and output data rate Power supply and gain control, 4 independent channels Instrumentation Technologies 24

25 Digitizer The idea besides the general purpose digitizer is to provide the user with a base from which to develop its own application. As described in Table 18, the instrument provides all the building blocks which are used for the other applications, from the RF input signals to the control system interface. Table 18: Capabilities of the multipurpose digitizer Libera Digit AC Libera Digit DC Dimensions (H W D) mm FPGA / CPU Zynq-7020 / ARM Cortex-A9 Ram memory 1 GB Max number of acquired data atoms 8 MS Platform management Passive cooling, Power over Ethernet, Network boot, SD card boot Input channels 4 A/D conversion 125 MHz / 14 bit Sampling clock Manual set, free running Timing signals 3 Maximum input signal +/- 1 V Input gain/attenuation fixed Bandwidth DC to 50 MHz 10 MHz to 700 MHz Input Impedance Selectable 1 MΩ / 50 Ω 50 Ω * Other component types/configuration can be discussed The available software and firmware infrastructures provide an already working template, with the possibility to extend its functionalities in a time-efficient manner, focusing only on its core part: the signal processing algorithms. Instrumentation Technologies 25

26 Your Idea Noticed anything missing in our instruments? Want more capabilities? Add your puzzle and get your instrument tailored to your specific requirements. Instrumentation Technologies 26

27 Software The software modules are implemented using the Libera BASE framework, which provides hardware abstraction and simplifies development and integration. Libera BASE also takes care of all general tasks such as platform management and health monitoring. Besides this, the Libera BASE is an extensible application layer with configuration parameters (registry tree) and signal acquisition, processing and dispatching functionality. On the top layer, it provides the Measurement and Control Interface (MCI) with a development package and an example CLI utility for open interaction in different control systems (see Figure 20 for details). All the software runs on a standard Linux Ubuntu distribution. The FPGAs reside in several modules and are smoothly integrated into the Libera BASE framework. Using the FPGA development kit, it is also possible to change the functionality and implement different processing algorithms in the extension module. Figure 20: Software structure The MCI allows the implementation of popular control system interfaces. The EPICS IOC, for example, runs inside the instrument and provides out-of-the-box access to process variables. Parameters and signals are accessible using a simple command-line utility, and access from Matlab is also supported. Instrumentation Technologies 27

28 Extensions Hardware extensions Extension modules are available for 2U, 19 beam position monitors. The GDX module extends the interconnection capabilities of the beam position monitors. Four protocol independent small form pluggable (SFP) slots can be used to build a closed loop of all the instruments in the accelerator. It features a Virtex6 FPGA which is completely open to user-developed applications. It can process the internal (within the chassis) and external position data at various data rates (Table 19). The SER module introduces the RS-485 interfaces which are directly controlled from the GDX module. The protocol and the baud rate are specified by the application in the GDX module (Table 20). Figure 21: GDX module Figure 22: SER module Table 19: Capabilities of GDX module FPGA chip Memory I/O interfaces SFP protocol GDX module XC6VLX240T-2FF784C 2 GB DDR3 4x SFP+ compliant, compliant multiprotocol operations, LVDS links to AMC connectors AURORA, GbE, others on request; independent to each SFP PCIexpress x4 bus interface to instrument s backplane On-board clock synthesizer and programmable VCXO for clock generation Board management is already established Table 20: Capabilities of SER module I/O interfaces Baud rate* Protocol* * Specified by application in the GDX module SER module RJ-25, LVDS links to GDX module Up to 2.5 Mbit/s Asynchronous protocol EIA 485, byte per byte Instrumentation Technologies 28

29 Software extensions Software extensions are possible on several levels (Table 21). Table 21: List of software extensions Extension Modification of current functionalities, implementation of new functionalities Addition of simple add-ons Complete application in the extension modules Control system interface Use of standard Linux/Ubuntu utilities Example Software updates, selected and provided by Instrumentation Technologies. Implementation of user-proposed functionalities (available for all users). Implementation of functionalities for specific users/applications. Functionalities that improve the user experience and do not interfere with mainstream applications. Installed as plug-ins. Demanding applications that typically work with real-time systems, such as timing systems or fast orbit feedback systems. The applications are unique and are developed in cooperation with the end user. EPICS IOC and TANGO DS are the two server processes currently available. They have been developed to fit the majority of Control Systems. There are, however, other Control Systems that require a different interface. Those can be addressed individually either by developing the interface or simply providing the MCI source code. Linux and Ubuntu offer a variety of utilities. Many of those can be installed and used on Libera instruments. Examples: Apache server, Twitter client, NTP, etc. An example of the complete application developed in the GDX module is provided in Figure 23. The data concentration block concentrates the beam positions of all daisy-chained. The orbit data then passes through several calculation phases and the PID controller. The output is usually the DAC value for the corrector magnets streamed through the optical or copper interface. 2 GB DDR3 memory is available for storing the data of interest. Figure 23: Example of application in the GDX module Instrumentation Technologies 29

30 Services and support Commissioning assistance Assistance in installation, commissioning and integration into the control system. On-site and remote support Get in touch with our skilled engineers, who have a full knowledge of the system. We will help you with hardware, software or system integration issues throughout the product s lifecycle. On-site demonstration and testing Try the instruments at your machine. One of our experts can visit you and assist you with testing. Training Hands-on training sessions on the use of Libera instruments are organized either on-site or at Instrumentation Technologies premises. Instrument customization Our flexible hardware and software architecture provides different options for extending functionalities. Warranty extension Extend the standard warranty period for the instruments and fix the cost of potential malfunctions in advance. Contact us at support@i-tech.si. Instrumentation Technologies 30

31 More at Visit our website to read more about Libera products, download conference papers on the use of Libera in different accelerators around the world, subscribe to the I-Tech Newsletter and learn about the next gathering of the community at Libera Workshop. Technical support Prompt and reliable. You can ask for on-site support or we can assist you remotely. You are also welcome to join us at the Libera Workshop training sessions to get the most out of Libera products.

32 BPM ELECTRONICS DIGITAL LLRF CLOCK TRANSFER SYSTEM BEAM LOSS MONITOR DIGITIZER YOUR IDEA Light sources (synchrotrons) 1 Hadron accelerators & colliders th generation light sources (FELs and ERLs) & hadron heavy ion LINACs Instrumentation Technologies, Velika pot 22, SI-5250 Solkan, Slovenia, P: , F: , E: info@i-tech.si, sales@i-tech.si, support@i-tech.si, W: Instrumentation Technologies, September 2016