I. Kempf, M.G. Abbott, L. Bobb, G.B. Christian
DLS, Harwell, United Kingdom
S. Duncan
University of Oxford, Oxford, United Kingdom
G. Rehm
HZB, Berlin, Germany
Funding:Diamond Light Source and Engineering and Physical Sciences Research Council The electron beam stability is critical for 4th generation light sources. As opposed to 10% of beam size up to 140 Hz at Diamond, advances in detector speed and resolution at Diamond-II increase the stability requirements to 3% up to 1 kHz. This paper presents a novel control methodology for the fast orbit feedback at Diamond-II, which will stabilise the beam using two arrays of 252 slow and 144 fast correctors and 252 beam position monitors at 100 kHz. In contrast to existing approaches that separate slow and fast feedback loops, our approach is based on a two-matrix factorisation called the generalised singular value decomposition (GSVD), which decouples the system into 144 two-input modes controlled by slow and fast magnets and 108 modes controlled by slow magnets only. The GSVD-based controller is implemented in the existing Diamond storage ring using a centralised communication architecture, such as planned for Diamond-II. We present results from the Diamond storage ring and simulation, which confirm that the proposed approach meets the target specification for Diamond-II.
R. Bronès, A. Bence, J. Bisou, N. Hubert, D. Pédeau, G. Pichon
SOLEIL, Gif-sur-Yvette, France
SOLEIL is upgrading its Fast Orbit Feedback platform to withstand coming obsolescence of electronic BPM and future evolutions of the machine. This new platform has to be compatible with current boundary devices such as BPM electronics or corrector power supplies, but it also shall evolve to interface future versions of these systems. A MTCA based platform was designed and installed. It is integrated in the control system by mean of a OPCUA server, and care has been taken to seamlessly toggle the closing of the feedback loop on the former or new FOFB platform. This paper will present the first tests and results conducted to commission this new system.
B. Keil, R. Ditter, F. Marcellini, G.M. Marinkovic, J. Purtschert, M. Rizzi, M. Roggli, D. Stephan, X. Wang
PSI, Villigen PSI, Switzerland
After more than 20 years of operation, the storage ring of the Swiss Light Source (SLS) will be replaced. The new ring called SLS 2.0 will have 40 times higher brilliance than SLS, thanks to an innovative low-emittance magnet lattice and a beam pipe with smaller aperture. For SLS 2.0, the ageing SLS BPM electronics will be incrementally replaced for the whole accelerator, including linac, booster, transfer lines and storage ring. This contribution presents the development status and latest prototype test results of the SLS 2.0 BPM system, including BPM pickups, mechanics, and electronics.
G. Kube, H.T. Duhme, J.L. Lamaack, F. Schmidt-Föhre, K. Wittenburg
DESY, Hamburg, Germany
A. Bardorfer, L. Bogataj, M. Cargnelutti, P. Leban, M.O. Oblak, P. Paglovec, B. Repič
I-Tech, Solkan, Slovenia
The PETRA IV project aims to upgrade the present PETRA III synchrotron into an ultra low-emittance source. The small emittances translate directly into much smaller beam sizes, thus imposing stringent requirements on the machine stability. In order to measure beam positions and control orbit stability to the level of 10% of beam size and divergence, a high resolution BPM system will be installed which consists of 788 individual monitors with the readout electronics based on MTCA.4. In order to fulfil the long-term drift requirement (< 1 micron over 7 days), several analog, digital and SW parts were taken from the Libera Brilliance+ and a new RTM module has been developed to be used as BPM electronics RFFE. In addition, its analogue RF switch matrix used for long-term stabilization was separated and placed close to the BPM pickup, hence enabling an additional stabilization of the RF cables. At present, a fully populated MTCA crate with 6 AMC boards for the readout of 12 BPMs is installed at PETRA III and is extensively being tested. This contribution summarizes the latest beam measurements, demonstrating the high performance of the BPM system and the external stabilization concept.
R. Panaś, A.I. Wawrzyniak
NSRC SOLARIS, Kraków, Poland
A. Curcio
LNF-INFN, Frascati, Italy
K. Łasocha
CERN, Meyrin, Switzerland
This paper presents a natural extension of prior theoretical investigations regarding the utilization of coherent diffraction radiation for assessing longitudinal characteristics of electron beams at Solaris. The study focuses on the measurement results obtained at the linac injector of the Solaris synchrotron and their analysis through a theoretical model. The findings are compared with previous estimates of the electron beam longitudinal profile. This paper contributes to the future diagnostics at the first Polish free electron laser (PolFEL) project, where it will be used for the optimization of particle accelerator performance.
T. Lefèvre, D. Alves, A. Boccardi, S. Jackson, F. Roncarolo, J.W. Storey, R. Veness, C. Zamantzas
CERN, Meyrin, Switzerland
The CERN accelerator complex stands out as an unique scientific tool, distinguished by its scale and remarkable diversity. Its capacity to explore a vast range of beam parameters is truly unparalleled, spanning from the minute energies of around a few keV and microampere antiproton beams, decelerated within the CERN antimatter factory, to the 6.8 TeV high-intensity proton beams that race through the Large Hadron Collider (LHC). The Super Proton Synchrotron (SPS) ring plays also a crucial role by slowly extracting protons at 400 GeV. These proton currents are then directed toward various targets, generating all sorts of secondary particle beams. These beams, in turn, become the foundation of a diverse fixed-target research program, enabling scientific exploration across a wide spectrum. Moreover, as CERN looks ahead to future studies involving electron-positron colliders, the development of cutting-edge diagnostics for low emittance, short electron pulses is also underway. This contribution serves as a snapshot, shedding light on the main R&D initiatives currently underway at CERN in the field of beam instrumentation.
B. Lorbeer, H.T. Duhme, I. Krouptchenkov, T. Lensch, D. Lipka, M. Werner
DESY, Hamburg, Germany
The European X-ray free-electron laser (E-XFEL) and the FLASH2020+ project for the free electron laser Hamburg (FLASH) at DESY in Hamburg, Germany foresee several machine upgrades in the years to come. At FLASH a whole undulator section in a shutdown starting in summer 2024 and finishing in autumn 2025 is going to be rebuild. Existing button beam position monitors installed in this section of the machine do not deliver sufficient signal strength for future required resolution specification and orbit feedback optimization for machine operation. The resolution limitations will be overcome by replacing the button-based beam position monitors with in-house developed cavity beam position monitors and compact microTCA based radio frequency receiver read-out electronics. The measurement system has been tested and evaluated in a test setup at FLASH.
H. Maesaka, N. Hosoda, S. Takano
RIKEN SPring-8 Center, Hyogo, Japan
H. Dewa, T. Fujita, N. Hosoda, H. Maesaka, M. Masaki, S. Takano
JASRI, Hyogo, Japan
We have developed MicroTCA.4-based versatile BPM readout electronics for the SPring-8 upgrade project, SPring-8-II (*). The input signals are processed by an rf front-end rear transition module (RTM) with band-pass filters, amplifiers, and step attenuators and digitized by 16-bit 370 MSPS high-speed digitizers on an advanced mezzanine card (AMC). The field-programmable gate array (FPGA) on the AMC calculates both single-pass and COD beam positions. The current BPM system at SPring-8 consists of approximately twenty single-pass dedicated BPMs and over two hundred other COD dedicated ones. In advance of SPring-8-II, so far, we renewed half of the single-pass dedicated BPM electronics to the MicroTCA.4. A graphical user interface (GUI) for the new BPM system was also developed and ready for tuning. The single-pass BPM resolution was confirmed to be better than 100 um for a 100 pC single bunch, sufficient for SPring-8-II. The other existing single-pass BPM electronics will also be renewed this summer. The full renewal of remaining COD dedicated BPM electronics to the versatile MicroTCA.4 ones is planned in the subsequent years before the construction of SPring-8-II. (*) H. Maesaka et al., "Development of MTCA.4-based BPM Electronics for SPring-8 Upgrade", Proc. IBIC’19, doi:10.18429/JACoW-IBIC2019-WEBO03
S.W. Jang, G. Hahn, J.Y. Huang, C. Kim, D. Kim, G. Kim, B.K. Shin, D.C. Shin, D. Song
PAL, Pohang, Republic of Korea
W.J. Song
POSTECH, Pohang, Republic of Korea
The emittance of the 4th-generation storage ring (4GSR) to be constructed in Cheongju-Ochang, Korea, is expected to be approximately 100 times smaller than the existing 3rd-generation storage ring. With the decrease in emittance, more precise beam stabilization is required. To meet this requirement, the resolution of the beam position monitor (BPM) system also needs to be further improved. We have conducted research and development on the electronics of the BPM system for the 4GSR storage ring. In order to perform fast orbit feedback in the 4GSR storage ring, we need to acquire turn-by-turn beam position data, with a desired beam position resolution of 1 ¿m. Additionally, prototypes of the bunch-by-bunch monitoring system are being developed for the transverse feedback system and longitudinal feedback system. The internally developed electronics are intended to be modified for future use as monitors for multi-bunch beam energy measurements at the end of the linear accelerator, by adjusting the logic accordingly. In this presentation, we will describe more details of the current status of the development of the beam position monitor electronics for the 4GSR in Korea.
A.J. Clapp
Royal Holloway, University of London, Surrey, United Kingdom
L. Bobb, G. Cook
DLS, Oxfordshire, United Kingdom
P. Karataev
JAI, Egham, Surrey, United Kingdom
This paper proposes a novel advancement in both the studies of Cherenkov diffraction radiation (ChDR) and beam instrumentation. The proposed beam position monitor (BPM) consists of two identical fused Silica prism radiators, with a fibre collimator attached to each one, which in turn are connected to a photodetector via a series of optical fibres. The setup will be implemented into the booster to storage ring transfer line at Diamond Light Source ¿ an electron light source with 3 GeV beam energy. The prototype proposed aims to test the feasibility of a full BPM utilising ChDR. If proven to be fully realisable, optical rather than capacitive BPM pickups could be more widely distributed. The paper will include the complete design and preliminary results of a one-dimensional BPM, utilising the ChDR effect.
D. Schneider, M. Arnold, U. Bonnes, A. Brauch, M. Dutine, R. Grewe, L.E. Jürgensen, N. Pietralla, F. Schließmann, G. Steinhilber
TU Darmstadt, Darmstadt, Germany
Funding:Work supported by DFG (GRK 2128), BMBF (05H21RDRB1), the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006) and the LOEWE Research Group Nuclear Photonics. The r-process fission cycle terminates the natural synthesis of heavy elements in binary neutron-star mergers. Fission processes of transuranium nuclides will be studied in electrofission reactions at the S-DALINAC*. Due to the minuscule fissile target, the experimental setup requires an active electron-beam-stabilization system with high accuracy and a beam position resolution in the submillimeter range. In this contribution, requirements and concepts of this system regarding beam-diagnostic elements, feedback control and readout electronics are presented. The usage of a beam position monitor cavity and optical transition radiation targets to monitor the required beam parameters will be discussed in detail. Additionally, various measurements performed at the S-DALINAC to assess requirements and limits for the beam-stabilization system will be presented. Finally, the option of using advanced machine learning methods such as neural networks and agent-based reinforcement learning will be discussed. *N. Pietralla, Nuclear Physics News, Vol. 28, No. 2, 4 (2018)
S. Jabłoński, H.T. Duhme, U. Mavrič, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
PETRA IV, a new fourth generation synchrotron radiation source planned at DESY, will require a transverse multi-bunch feedback (T-MBFB) system to damp transverse instabilities and keep the beam emittance low. The critical part of the T-MBFB is a detector that must measure bunch-by-bunch, i.e. every 2 ns, beam position variations with the resolution not worse than 1 ¿m for the dynamic beam range of ±1 mm. In this paper, we present the conceptual design of the T-MBFB detector from the beam position pickups to the direct sampling ADCs. We analyse the noise sources limiting the detector resolution and present measurement results based on the evaluation modules.
S. Banerjee, M.G. Abbott, L. Bobb, I. Kempf
DLS, Harwell, United Kingdom
I. Kempf
University of Oxford, Oxford, United Kingdom
At Diamond Light Source, the fast orbit feedback (FOFB) uses one array of correctors and the controller is designed using the internal model control (IMC) structure. The Diamond-II upgrade will introduce an additional array of fast correctors and a new controller that is designed using the generalised modal decomposition, increasing the overall closed-loop bandwidth from 140 Hz to 1 kHz. Although simulation results have shown that the resulting beam displacement is within specification in all straights, they have also shown that the performance on long straights is limited, particularly in the vertical plane. In this paper, the controller is tuned in order to increase the FOFB performance in long straights by introducing a mode-by-mode regularisation parameter. The performance of the controller beyond 1 kHz is assessed using new disturbance data and a new measurement noise model, showing that the Diamond-II performance criteria are met, even in the presence of measurement noise.
Funding:Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy Top-up operation becomes routine in the light sources. The goal of the top-up operation is to keep the current of the circulating beam stable to avoid variations of the heat load on the beamline optics. It is also considered for the electron-ion collider to maintain the polarization of the electron beam. Frequent re-injection makes measurement of the beam lifetime very difficult if possible. Since, only part of the bunch train is refreshed during the injection cycle then the distribution of the bunch charges in the train has a characteristic saw-tooth distribution. The slope of saw tooth and step in the bunch charge distribution is defined by the lifetime and filling frequency. Both parameters can be used for the measurement. The data for processing can be obtained either from fast current transformer or from the raw ADC signal from beam position monitor. In this paper we present the theoretical considerations as well as experimental data from NSLS-II storage ring.
Funding:Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy Coherent Electron Cooling experiment carried out at RHIC requires small slice emittance of 15 MeV electron beam with high peak current. In this paper we describe the system for slice emittance measurement utilizing transverse deflecting cavity and slit. The image of the beam passing through the slit is used to measure slice intensity and angular divergence. Beam size at slit location is measured using scan of the beam across the slit with trim. The angular kick by the trim is taken into the account during calculations. Data processing and the experimental results are presented.
The SuperKEKB electron-positron collider, which started the commissioning in February 2016, is a luminosity frontier machine for the search for new physics. In this presentation, we review the main challenges we face for the high-energy and low-emittance beam at SuperKEKB, fast and low-noise beam-orbit feedback system, X-ray beam-profile monitors for measurements for the beam size of ¿10 um, novel diamond mirrors with extremely high thermal conductivity for extracting synchrotron radiation, and various type’s beam loss diagnostics for the identification or possibly early detection of sudden beam losses. This presentation includes future directions of the R&D–-X-ray interferometry for micron-level beam size measurements and fast optics measurements with the gated turn-by-turn BPMs–-towards next-generation light source facilities and high-energy colliders.
First Direct Measurement of Electron and Positron Bunch Characteristics during Positron Capture Process at the Positron Source of the SuperKEKB B-Factory
Electron (e-) and positron (e+) bunch characteristics were directly measured for the first time using wideband beam monitors (WBMs) and a detection system at the e+ source of the SuperKEKB B-factory. Both secondarily-generated e- and e+ bunches after the e±production target were clearly identified in their dynamical capture process at locations of the WBMs under two-bunch acceleration scheme. Not only the longitudinal but also transverse bunch characteristics, the time intervals between the e- and e+ bunches, the bunch lengths, transverse bunch positions, and bunch charges were simultaneously separately measured for each bunch as functions of the capture phase to investigate their dynamical capture process. The results show that quite symmetric dynamical behaviors for the e- and e+ bunch characteristics were clearly observed. The new WBMs open up a new window for direct measurements of both the e- and e+ bunches during their dynamical capture process and in the optimization procedure of the e+ bunch intensity in multidimensional parameter spaces at any e+ sources. The historical backgrounds for introducing and implementing the new WBMs are also described in this report.
J.G. Wang, B. Liu, W. Wu
SARI-CAS, Pudong, Shanghai, People’s Republic of China
The femtosecond synchronization and distribution system of the Shanghai soft X-ray free-electron laser facility (SXFEL) and Shanghai high repetition rate XFEL and extreme light facility (SHINE) are based on the optical pulse trains generated by passively mode-locked lasers. The passively mode-locked laser has ultralow noise in the high offset frequency (<5 fs, [1 kHz- 1 MHz]). In this paper, we report precise synchronization of the low-noise passively mode-locked laser to the radio frequency (RF) master oscillator. RF-based phase-locked loop scheme, the absolute jitter of the phase-locked passively mode-locked laser is less than 20 fs integrated from 10 Hz up to 1 MHz.
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J.A. Mock, A.S. Fisher, R.T. Herbst, P. Krejcik, L. Sapozhnikov
SLAC, Menlo Park, California, USA
Beam power at the LCLS-II linac and FEL can be as high as several hundered kW with CW beam rates up to 1 MHz. The new MPS has a latency of less than 100 µs to prevent damage when a fault or beam loss is detected. The MPS architecture encompasses the multiple FEL beamlines served by the SC linac and can mitigate a fault in one beamline without impacting the beam rate in a neighboring beamline. The MPS receives inputs from various devices including loss monitors and charge monitors as well as magnet power supplies and BPMs to pre-emptively turn of the beam if a fault condition is detected. Link nodes distributed around the facility gather the input data and stream it back to a central processor that signals other link nodes connected to beam rate control devices. Commmissioning and experience with the new system will be described.
T. Lensch, D. Lipka, Re. Neumann, M. Werner
DESY, Hamburg, Germany
The SINBAD (Short and INnovative Bunches and Ac-celerators at DESY) facility, also called ARES (Acceler-ator Research Experiment at SINBAD), is a conventional S-band linear RF accelerator allowing the production of lowcharge ultra-short electron bunches within a range of currently 0.01 pC to 250 pC. The R&D accelerator also hosts various experiments. Especially for the medical eFLASH experiment an absolute, non-destructive charge measurement is needed. Therefore different types of monitors are installed along the 45 m long machine: A new Faraday Cup design had been simulated and realized. Further two resonant cavities (Dark Current monitors) and two beam charge transfomers (Toroids) are installed. Both, Dark Current Monitors and Toroids are calibrated independently with laboratory setups. At the end of the accelerator a Bergoz Turbo-ICT is installed. This paper will give an overview of the current installations of charge monitors at ARES and compare their measured linearity and resolution.
R.Y. Qiu, W.L. Huang, F. Li, M.A. Rehman, Z.X. Tan, Zh.H. Xu, R.J. Yang, T. Yang
IHEP CSNS, Guangdong Province, People’s Republic of China
M.Y. Liu, L. Zeng
IHEP, Beijing, People’s Republic of China
Q.R. Liu
UCAS, Beijing, People’s Republic of China
Funding:National Natural Science Foundation, U2032165 The Associated Proton beam Experiment Platform (APEP) beamline is the first proton irradiation facility to use naturally-stripped protons which come from H− beams interacting with the residual gas in the linac beampipe at CSNS. The stripped beam current, which is in the order of 0.1% of the original H− beam and approximately 10 mi-croamperes, should be measured precisely to provide the proton number for irradiation experiments. Therefore, a low-intensity beam current measurement system was developed with considerations to eliminate the external interferences. An anti-interference design is adopted in this system with an elaboration of probes, cables and electronic low-noise technology to minimize the impact of environmental noise and interferences. This improves the signal-to-noise ratio and enables a more precise measurement of the microampere-level pulsed beam cur-rent. The system was installed and tested during the summer maintenance in 2021 and 2022. It shows a good agreement with the measurement of the Faraday cup.
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A.S. Fisher, M. Bai, T. Frosio, A. Ratti, J. Smedley, J. Wu
SLAC, Menlo Park, California, USA
I.S. Mostafanezhad, B. Rotter
Nalu Scientific, LLC, Honolulu, USA
FELs require a reproducible distribution of the bunch core at the undulator entrance for robust and reliable lasing. However, various mechanisms drive particles from the core to form a beam halo, which can scrape the beampipe of the undulator and damage its magnets. Collimators can trim the halo, but at the 1-MHz repetition rate of SLAC’s LCLS-II superconducting linac, the collimator jaws can be activated and damaged. The Machine Protection System (MPS) can detect excessive radiation and halt the beam, but repeated MPS trips lead to significant downtime. Halo control begins by studying its structure, formation, and evolution, using a sensitive halo monitor. To that end, we are developing a pixellated diamond sensor. Diamond offers a dynamic range of up to 7 orders of magnitude, extending from the edge of the core to the faint halo expected at greater distances. Nalu Scientific has developed fast electronics for high-rate shot-by-shot readout. Initial tests are starting with a prototype 16-pixel sensor at the beam dump of SLAC’s FACET-II test facility. The tests and simulations will guide more elaborate sensor designs.
A. Brauch, M. Arnold, M. Dutine, J. Enders, R. Grewe, L.E. Jürgensen, N. Pietralla, F. Schließmann, D. Schneider
TU Darmstadt, Darmstadt, Germany
Funding:Work supported by the State of Hesse within the Cluster Project ELEMENTS (Project ID 500/10.006) and by DFG (GRK 2128 AccelencE). The S-DALINAC is a thrice recirculating electron accelerator for high resolution electron scattering experiments with a continuous-wave beam at a frequency of 2.9972(1) GHz. Short bunches are crucial to enable tuning of the machine for operation as an energy-recovery linear accelerator* **. Currently, measurements of this beam parameter are accomplished by using the radio-frequency zero-crossing method: here, a momentum spread chirp is induced and the transverse beam profile in a downstream located dispersive section is measured with a scintillating screen providing an upper limit of the bunch length. Since this method is time consuming, a new setup for these measurements using a streak camera is developed. Optical transition radiation from an aluminum-coated Kapton target is used to map the bunch length information to a light pulse which enables an accurate measurement compared to a scintillating screen. The light pulse can then be evaluated with the streak camera by projecting its length onto the transverse dimension on a phosphor screen. This contribution will present the current status of the measurement setup as well as its design and properties. *Michaela Arnold et al., Phys. Rev. Acc. Beams 23, 020101 (2020). **F. Schliessmann et al., Nat. Phys. 19, 597-602 (2023).
R. Yadav, S. Preu
IMP, TU Darmstadt, Darmstadt, Germany
A. Penirschke
THM, Friedberg, Germany
Funding:The work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05K22RO1 for applications at HZDR, Dresden, LAS at KIT and DELTA at TU Dortmund. The Zero-Bias Schottky Diode (ZBSD) and field effect transistor (TeraFET) based Terahertz (THz) detectors be- come more and more important for beam diagnosis and alignment at THz generating accelerator facilities. The roll- off factor of the detectors at higher THz frequencies requires wide-band amplifiers to enhance the IF signal from a few µW to nW well above the noise floor of the following post detection electronics. Connecting external amplifiers to the detectors via rf cables would enhance the signal losses even further and degrade the signal to noise ratio (SNR). In order to maximize the SNR, it is necessary to have on-chip amplifier integrated in the intermediate frequency (IF) circuit of the detector in the same housing. In this work, we present the design and parametric analysis of components for transition to an IF circuit, which will be integrated in the ZBSD and TeraFET on chip with amplifier in the same housing. The design analysis has been done to find the optimal parameters. The broader IF circuit will enhance the detector resolution to capture pulses in the picosecond range with the help of fast post detection electronics. [*] R. Yadav et al., doi:10.3390/s23073469 [**] S. Preu et al., doi:10.1109/TTHZ.2015.2482943 [***] A. Penirschke et al., doi:10.1109/IRMMW-THz.2014.6956027
B.E.J. Scheible, A. Penirschke
THM, Friedberg, Germany
W. Ackermann, H. De Gersem
TEMF, TU Darmstadt, Darmstadt, Germany
M.K. Czwalinna, T.A. Nazer, H. Schlarb, S. Vilcins
DESY, Hamburg, Germany
M. Freitag, M. Kuntzsch
HZDR, Dresden, Germany
Funding:This work is supported by the German Federal Ministry of Education and Research (BMBF) under Contract No. 05K19RO1 and 05K22RO2. A vacuum sealed prototype of an electro-optical bunch-arrival-time monitor has been commissioned in 2023. It comprises of a pickup-structure and a low-pi-voltage ultra-wideband traveling wave electro-optical modulator. The stainless-steel body of the pickup structure is partially produced by additive manufacturing and comprises four pickups as well as an integrated combination network on a printed circuit board. This novel design aims to enable single-shot bunch-arrival-time measurements for electron beams in free-electron lasers with single-digit fs precision for low bunch charges down to 1 pC. The theoretical jitter charge product has been estimated by simulation and modeling to be in the order of 9 fs pC. The new prototype is tailored for validation experiments at the ELBE accelerator beamline. In this contribution first measurement results are presented.
W.L. Huang, X.J. Nie
IHEP CSNS, Guangdong Province, People’s Republic of China
M.Y. Liu, X.Y. Liu, Y.F. Sui
IHEP, Beijing, People’s Republic of China
Q.R. Liu
UCAS, Beijing, People’s Republic of China
Funding:Natural Science Foundation of Guangdong Province, 2021A1515010269 National Natural Science Foundation, 11475204 During the upgrade of linac in CSNS-II, the beam in-jection energy will increase from 80.1MeV to 300MeV and the beam power from 100kW to 500kW. A com-bined layout of superconducting spoke cavities and ellip-tical cavities is adopted to accelerate H− beam to 300MeV. Due to a ~10ps short bunch width at the exit of the spoke SC section, the longitudinal beam density dis-tribution will be measured by bunch shape monitors using low energy secondary emission electrons. As the most important part of a bunch shape monitor, a prototype 324MHz RF deflector is designed and tuned on the basis of a quasi-symmetric λ/2 325MHz coaxial resona-tor, which was fabricated for the C-ADS proton accelera-tor project. Preliminary parameters of the bunch shape monitor are presented. Simulation of the RF deflector and test results in the laboratory are described and analysed.
A. Schlögelhofer, T. Lefèvre, S. Mazzoni, E. Senes
CERN, Meyrin, Switzerland
L. Duvillaret
KAPTEOS, Sainte-Helene-du-Lac, France
A. Schlögelhofer
TU Vienna, Wien, Austria
The properties of Cherenkov diffraction radiation (ChDR) have been studied extensively during the recent years to be exploited for non-invasive beam diagnostic devices for short bunches. The dependence of charge and the influence of the bunch form factor on the coherent part of the radiated spectrum have been demonstrated and studied in the past. However, the actual field strength of coherent ChDR as well as its study in time domain need further investigation. In this contribution we are using electro-optical techniques to investigate and quantify these parameters. The electro-optical read-out brings the advantage of high bandwidth acquisition and insensitivity to electromagnetic interference, whereas at the same time a large fraction of the acquisition setup can be installed and operated outside of the radiation controlled areas. We will present experimental results from the CLEAR facility at CERN as well as simulations of the peak field of the temporal profile of beam-generated ChDR pulses.
E. Senes, S. Mazzoni, M. Turner, G. Zevi Della Porta
CERN, Meyrin, Switzerland
D.A. Cooke, F.E. Pannell, M. Wing
UCL, London, United Kingdom
The first run of the AWAKE experiment successfully demonstrated the acceleration of an electron beam in the plasma wakefields of a relativistic proton beam. The planned second run will focus on the control of the emittance of accelerated electrons, requiring an upgrade of the existing spectrometer. Preliminary measurements showed that this might be achieved by improving the resolution of the scintillator and with a new design of the optical system. This contribution discusses the application of a digital camera array in close proximity of the spectrometer scintillator, to enable the accelerated electron beam emittance measurement.
The lasing performance of a Free Electron Laser (FEL) strongly relies on a precise characterization of the electron bunch length and on the control and stabilization of the bunch compression settings of the machine under normal user operations. In a FEL driver linac, the so-called Bunch Compressor Monitors (BCMs) normally ensure the non-invasive monitoring of the electron bunch length. BCMs, being sensitive to the temporal coherent threshold of the radiation energy emitted by the electron beam crossing the last dipole of a magnetic chicane or a holed diffraction screen just downstream, can provide a bunch length dependent signal resulting from the integration of the detected radiation pulse energy over the acceptance frequency band of the detector. Thanks to the non-invasiveness, BCMs are primary diagnostics in a FEL to stabilize the bunch compression by feeding back the RF settings of the accelerating structure. In this contribution, we present a formal method to determine an absolute measurement of the electron bunch length from the analysis of a BCM signal (*). (*) G.L. Orlandi, Absolute and non-invasive determination of the electron bunch length in a Free Electron Laser using a Bunch Compressor Monitor, https://doi.org/10.48550/arXiv.2305.17042, https://doi.org/10.21203/rs.3.rs-3228455/v1
J.C. Dooling, A.R. Brill, N. Kuklev, I. Lobach, A.H. Lumpkin, N. Sereno, Y. Sun
ANL, Lemont, Illinois, USA
Funding:Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357. We report on measurements of beams from thermionic cathode (TC) rf guns in the Advanced Photon Source S-Band Linac. These measurements include the macropulse out of both new and existing TC guns as well as the observation of microbunching within the micropulses of these beams. A gun chopper limits the macropulse FWHM duration to the 10-ns range. Our objectives were to analyse the new TC gun and investigate microbunching within a TC-rf-gun-generated beam. Our diagnostics elucidated longitudinal beam structures from the ns to the fs time scales. Coherent transition radiation (CTR) interferometers responding to far-infrared wavelengths were employed after each compression stage to provide the autocorrelations of the sub-ps micropulse durations. The first compression stage is an alpha magnet and the second a chicane. A CCD camera was used to image the beam via optical transition radiation from an Al screen at the end of the linac and also employed to measure coherent optical transition radiation (COTR) in the visible range. The COTR diagnostic observations, implying microbunching on a fs time scale, are presented and compared with a longitudinal space-charge impedance model.
M.W. Bruker, J.M. Grames, J. Guo, J. Musson, S.A. Overstreet, G.-T. Park, T.E. Plawski, M. Poelker, R.A. Rimmer, H. Wang, C.M. Wilson, S. Zhang
JLab, Newport News, Virginia, USA
M.H. Pablo, B.F. Roberts, D. Speirs
Electrodynamic, Albuquerque, New Mexico, USA
Funding:Work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177. Multi-Harmonic driver development supported by SBIR DE-SC0020566. A harmonically resonant kicker cavity designed for beam exchange in a circulator cooler* was built and successfully tested at the Upgraded Injector Test Facility (UITF) at Jefferson Lab. This type of cavity is being considered for the injection scheme of the Rapid Cycling Synchrotron at the Electron-Ion Collider, where the spacing of neighboring bunches demands very short kicks. Operating with five transversely deflecting modes simultaneously that resonate at 86.6 MHz and consecutive odd harmonics thereof, the prototype cavity selectively deflects 1 of 11 electron bunches while leaving the others unperturbed. An RF driver was developed to synthesize phase- and amplitude-controlled harmonic signals and combine them to drive the cavity while also separating the modes from a field-probe antenna for RF feedback and dynamic tuning. Beam deflection was measured by sweeping the cavity phase; the deflection waveform agrees with expectations, having sub-nanosecond rise and fall times. No emittance increase is observed. Harmonically resonant cavities like the one described provide a new capability for injection and extraction at circulators and rings. * G.T. Park et al., "Beam exchange of a circulator cooler ring with an ultrafast harmonic kicker", Phys. Rev. Accel. Beams 24, 061002
T. Sieber, L. Crescimbeni, D.M. Haider, M. Schwickert, T. Stöhlker
GSI, Darmstadt, Germany
D.M. Haider, N. Marsic
TEMF, TU Darmstadt, Darmstadt, Germany
M. Schmelz, R. Stolz, V. Zakosarenko
IPHT, Jena, Germany
F. Schmid
FSU Jena, Jena, Germany
T. Stöhlker
IOQ, Jena, Germany
T. Stöhlker, V. Tympel
HIJ, Jena, Germany
J. Tan
CERN, Meyrin, Switzerland
V. Zakosarenko
Supracon AG, Jena, Germany
The Cryogenic Current Comparator (CCC) is a SQUID based superconducting device for intensity measurement, firstly proposed as a beam diagnostics instrument in the 90s at GSI. After prove of principle the CCC was introduced into other facilities, attesting great potential for high resolution measurements but at the same time considerable mechanical and cryogenics challenges and costs. In the course of plannings for FAIR the CCC has been revitalized. Systematic investigations started, involving commercially available SQUID systems, which led to improvements of detector and cryostat. The developments resulted in nA spill measurements at GSI (2014) followed by the installation of a CCC in CERN Antiproton Decelerator (AD), which has in the meantime become a key instrument. Since then optimization of the device is ongoing, with respect to various operating conditions, system robustness, current resolution and last but not least system costs. Alternative CCC versions with improved magnetic shielding have been developed as well as ¿Dual Core‘ versions for background noise reduction. We give an overview of CCC optimization and development steps, with focus on applications at GSI and FAIR.
D. Lipka, T. Lensch, Re. Neumann, M. Werner
DESY, Hamburg, Germany
The ARES facility (Accelerator Research Experiment at SINBAD) is an accelerator to produce low charge ultra-short electron bunches within a range of currently 0.5 pC to 200 pC. Especially for eFLASH experiments at ARES an absolute, non-destructive charge measurement is required. To measure an absolute charge of individual bunches different types of monitors are installed. A destructive Faraday Cup is used as reference charge measurement device. To measure the charge non-destructively 2 Toroids, 1 Turbo-ICT and 2 cavity monitors are installed. The latter system consists of the cavity, front-end electronics with logarithmic detectors and µTCA ADCs. The laboratory calibration of the cavity system is performed by using an arbitrary waveform generator which generate the same waveform like the cavity with beam. This results in a non-linear look-up table used to calculate the ADC amplitude in charge values independent of beam-based calibration. The measured charges from the cavity monitors agree very well within few percent in comparison with the Faraday Cup results.
S.T. Littleton
Stanford University, Stanford, California, USA
A.S. Fisher, C. Huang, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
The LESA beamline is designed to transport dark current from the LCLS-II and LCLS-II-HE superconducting linacs to the End Station A for various fixed target experiments. The primary experiment is expected to be the Light Dark Matter eXperiment (LDMX) which required beam currents of a few pA. The operation of the beam line much be parasitic to the LCLS-II / LCLS-II-HE FEL operation. The dark current in the LCLS-II is expected to be at the nA-level which will be below the resolution of most of the LCLS-II diagnostics (it will be degraded before the experiments as necessary). This paper will describe a possible non-destructive diagnostic using synchrotron radiation that could be applied at multiple locations along the LCLS-II and the LESA beamline.
R. Yadav, S. Preu
IMP, TU Darmstadt, Darmstadt, Germany
J.M. Klopf, M. Kuntzsch
HZDR, Dresden, Germany
A. Penirschke
THM, Friedberg, Germany
Funding:The work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05K22RO1 for applications at HZDR, Dresden, LAS at KIT and DELTA at TU Dortmund. Semiconductor-based broadband room-temperature Terahertz (THz) detectors are well suitable for beam diagnosis and alignment at accelerator facilities due to easy handling, compact size, no requirement of cooling, direct detection and robustness. Zero-Bias Schottky Diode (ZBSD) based THz detectors are highly sensitive and extremely fast, enabling the detection of picosecond scale THz pulses. This contribution gives an overview of direct THz detector technologies and applications. The ZBSD detector developed by our group has undergone several tests with table-top THz sources and also characterized with the free-electron laser (FEL) at HZDR Dresden, Germany up to 5.56 THz. In order to understand the rectification mechanism at higher THz frequencies, detector modelling and optimization is essential for a given application. We show parametric analysis of a antenna-coupled ZBSD detector by using 3D electromagnetic field simulation software (CST). The results will be used for optimization and fabrication of next generation ZBSD detectors, which are planned to be commissioned at THz generating FEL accelerator facilities in near future. [1] R. Yadav et al., doi:10.3390/s23073469 [2] M. Hoefleet al., doi:10.1109/IRMMW-THz.2013.6665893 [3] R. Yadav et al., doi:10.18429/JACoW-IPAC2022-MOPOPT013
R.J. Michnoff, L. DeSanto, C.M. Degen, S.H. Hafeez, R.L. Hulsart, J.P. Jamilkowski, J. Mead, K. Mernick, G. Narayan, P. Oddo, M.C. Paniccia, J.A. Pomaro, A.C. Pramberger, J.C. Renta, F. Severino
BNL, Upton, New York, USA
D.M. Gassner
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
Funding:Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Many beam instrumentation systems at Brookhaven National Laboratory¿s Collider-Accelerator complex are over 20 years old and in need of upgrading due to obsolete components, old technology and the desire to provide improved performance and enhanced capabilities. In addition, many new beam instrumentation systems will be developed for the future Electron Ion Collider (EIC) that will be housed in the existing Relativistic Heavy Ion Collider (RHIC) tunnel. A new BNL designed custom hardware architecture is planned for both upgrades in the existing facility and new systems for the EIC. A general-purpose carrier board based on the Xilinx Zynq Ultrascale+ System-on-Chip (SoC) will interface with a family of application specific daughter cards to satisfy the requirements for each system. This paper will present the general architecture that is planned, as well as details for some of the application specific daughter cards that will be developed.
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O. Sedláček, A.R. Churchman, A. Rossi, G. Schneider, C.C. Sequeiro, K. Sidorowski, R. Veness
CERN, Meyrin, Switzerland
M. Ady, S. Mazzoni, M. Sameed
European Organization for Nuclear Research (CERN), Geneva, Switzerland
P. Forck, S. Udrea
GSI, Darmstadt, Germany
O. Sedláček, O. Stringer, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
O. Sedláček, O. Stringer, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Webber-Date
Cockcroft Institute, University of Liverpool, Liverpool, United Kingdom
The ever-developing accelerator capabilities of increasing beam intensity, e.g. for High Luminosity LHC (HL-LHC), demand novel non-invasive beam diagnostics. As a part of the HL-LHC project a Beam Gas Curtain monitor (BGC), a gas jet-based fluorescence transverse profile monitor, is being developed. The BGC uses a supersonic gas jet sheet that traverses the beam at 45° and visualizes a two-dimensional beam-induced fluorescent image. The principle of observing photons created by fluorescence makes the monitor insensitive to present electric or magnetic fields. Therefore, the monitor is well suited for high-intensity beams such as low-energy electron beam of Hollow Electron Lens (HEL), and HL-LHC proton beam, either as a profile or an overlap monitor. This talk will focus on the first gas jet measured transverse profile of the 7keV hollow electron beam. The measurements were carried out at the Electron Beam Test Stand at CERN testing up to 5A beam for HEL. A comparison with Optical Transition Radiation measurements shows consistency with the BGC results. The BGC installation of January 2023 at LHC is shown, including past results from distributed gas fluorescence tests.
M. Chung, C.K. Sung
UNIST, Ulsan, Republic of Korea
We have developed a highly precise 4D emittance meter for X-Y coupled beams with 4D phase-space (x-x’, y-y’, x-y’, y-x’) which utilizes an L-shaped slit and employs novel analysis techniques. Our approach involves two types of slit-screen image processing to generate pepper-pot-like images with great accuracy. One which we call the "differential slit" method, was developed by our group. This approach involves combining two slit-screen images, one at position x and the other at position x + the size of the slit, to create a differential slit image. The other method we use is the "virtual pepper-pot (VPP)" method, which combines x-slit and y-slit images to produce a hole (x,y) image. By combining that hole images, we are able to take extra x-y’ and y-x’ phase-space. The "differential slit" method is crucial for accurately measuring emittance. Through simulations with 0.1 mm slit width using Geant4, the emittance uncertainties for a 5 nm rad and 0.2 mm size electron beam were 5% and 250% with and without the "differential slit", respectively. In this presentation, we provide a description of the methodology, the design of slit, and the results of the 4D emittance measurements.
J. Marroncle, P. Abbon, F. Belloni, F. Bénédetti, T. Hamelin, J.-Ph. Mols, L. Scola
CEA-DRF-IRFU, France
B. Bolzon, N. Chauvin, D. Chirpaz-Cerbat, M. Combet, M.J. Desmons, Y. Gauthier, C. Lahonde-Hamdoun, Ph. Legou, O. Leseigneur, Y. Mariette, V. Nadot, M. Oublaid, G. Perreu, F. Popieul, B. Pottin, Y. Sauce, J. Schwindling, F. Senée, O. Tuske, S. Tzvetkov
CEA-IRFU, Gif-sur-Yvette, France
I. Dolenc Kittelmann, A.A. Gevorgyan, H. Kocevar, R. Tarkeshian, C.A. Thomas
ESS, Lund, Sweden
Several Non-invasive Profile Monitors are being in-stalled along the accelerator to support the commissioning, tuning and operation of the powerful proton based ESS linear accelerator. In the low energy parts of the ESS linac (3.6 MeV to 90 MeV), the residual gas pressure is high enough to measure the transverse beam profile by using fluorescence induced by the beam on the gas molecules. However, in the ESS linac sections above 90 MeV, protons are accelerated by superconductive cavities working at cryogenic temperatures and high vacuum. Therefore, the signal based on the fluorescence process is too weak, while ionization can counteract this drawback. We have provided five IPM (Ionization Profile Monitors) pairs for energies ranging from 100 to 600 MeV. The design of such monitors is challenging due to weak signal (as a result of high proton energy and low pressure <10-9 mbar), tight space constraints inside the vacuum chamber, space charge effect, ISO-5 cleanliness requirement, and electrode polarization at ±15 kV. This publication will detail the development we followed to fulfil the ESS requirements.
K.P. Wootton, W. Berg, W.P. Burns III, J.R. Calvey, J.C. Dooling, L. Erwin, A.H. Lumpkin, N. Sereno, S.E. Shoaf, S.G. Wang
ANL, Lemont, Illinois, USA
Funding:This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. A new synchrotron light monitor has been tested for the booster synchrotron of the Advanced Photon Source. Visible light synchrotron radiation is collected by a mirror on a path tangential to the electron beam orbit, and directed to an optical imaging system and camera. This is planned to be a non-intercepting, transverse beam-size monitor even with the higher stored beam charges (~17 nC) needed for the Advanced Photon Source Upgrade. In the present work, we describe the present synchrotron radiation diagnostic layout. An analysis of the synchrotron radiation power on the mirror, the optical layout with components, and features of the control system will be presented.
K.P. Wootton, W. Berg, M. Borland, A.R. Brill, J.M. Byrd, S. Chitra, J.T. Collins, J.C. Dooling, J.N. Edwards, L. Erwin, G.I. Fystro, T. Grabinski, M.J. Henry, E.E. Heyeck, J.E. Hoyt, R.T. Keane, S.H. Lee, J. Lenner, I. Lobach, A.H. Lumpkin, A. Puttkammer, V. Sajaev, N. Sereno, Y. Sun, J. Wang, S.G. Wang, A. Zholents
ANL, Lemont, Illinois, USA
Funding:This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. The Linac Extension Area has been developed into a beamline area for testing accelerator components and techniques. Beginning commissioning activities in February 2023, we have delivered the first electron beam to the Linac Extension Area at the Advanced Photon Source at 425 MeV. In the present work, we outline the stages of re-commissioning the electron beamline. We summarise measurements of the electron beam transport through the accelerator. We outline scenarios used to verify the adequacy of radiation shielding of the beamline, and measured shielding performance.
Funding:This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359. The Booster Neutrino Beamline experiment requested a new secondary electron emission multiwire profile monitor installation. The device had to be durable in high radiation conditions and mounted within a large 10 foot airtight steel fixture for installation near the beam target. Previous iterations of multiwire suffered radiation damage to both the connectors and wires. To ensure accurate horizontal and vertical beam profile measurements, an updated design was proposed, designed, and constructed. The new BNB multiwire utilizes 3 mil diameter gold-plated tungsten sense wires soldered to vertical and horizontal Alumina-96 ceramic planes, 50 wires per plane. Radiation hard Kapton insulated 30 gauge wires carry the output signals. Profiles are readout through charge integrator scanner electronics. This paper will detail the design and functionality of the BNB target multiwire and present relevant beam profile data.
Funding:This work was produced by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. The current program at Fermilab involves the construction of a new superconducting linear accelerator (LINAC) to replace the existing warm version. The new LINAC, together with other planned improvements, is in support of proton beam intensities in the Main Injector (MI) that will exceed 2 MW. Measuring the transverse profiles of these high intensity beams in a ring requires non-invasive techniques. The MI uses ionization profile monitors as its only profile system. An alternative technique involves measuring the deflection of a probe beam of electrons with a trajectory perpendicular to the proton beam. This type of device was installed in MI and initial studies of it have been previously presented. This paper will present the status and recent studies of the device utilizing different techniques.
R.M. Thurman-Keup, M. El Baz, V.E. Scarpine
Fermilab, Batavia, Illinois, USA
Funding:This work was produced by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. The Proton Improvement Plan - II (PIP-II) is a new linear accelerator (LINAC) complex being built at Fermilab. It is based on superconducting radiofrequency cavities and will accelerate H− ions to 800 MeV kinetic energy before injection into the existing Booster ring. Measurements of the profile of the beam along the LINAC must be done by non-intercepting methods due to the superconducting cavities. The method chosen is photoionization of a small number of H− by a focused infrared laser, aka laserwire. The number of ionized electrons is measured as a function of laser position within the H− beam. To aid in the design of the collection mechanism, a simulation was written in MATLAB with input from the commercial electromagnetic simulation, CST. This simulation calculates the number and positions of the liberated electrons and tracks them through the magnetic collection and H− beam fields to the collection point. Results from this simulation for various points along the LINAC will be shown.
R.M. Thurman-Keup, C.E. Lundberg, D. Slimmer, J.R. Zagel
Fermilab, Batavia, Illinois, USA
Funding:This work was produced by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. One of the on-going issues with the use of microchannel plates (MCP) in the ionization profile monitors (IPM) at Fermilab is the significant decrease in gain over time. There are several possible issues that can cause this. Historically, the assumption has been that this is aging, where the secondary emission yield (SEY) of the pore surface changes after some amount of extracted charge. Recent literature searches have brought to light the possibility that this is an initial ’scrubbing’ effect whereby adsorbed gasses are removed from the MCP pores by the removal of charge from the MCP. This paper discusses the results of studies conducted on the IPMs in the Main Injector at Fermilab.
H. Shaker, A. Bertwistle, E.J. Ericson, Y. Yousefi Sigari
CLS, Saskatoon, Saskatchewan, Canada
E. Soltan, Y. Yousefi Sigari
University of Saskatchewan, Saskatoon, Canada
There is a plan in the Canadian Light Source (CLS) to replace the current Linac with a new one from Research Instruments GmbH in mid-2024. The first straight section of LTB (Linac-To-Booster) was upgraded to have two BPMs with a 4.79m drift between them, and two phosphor screens were replaced by YAG screens. A new BPM and a YAG-based screen station upgraded the following 90-degree achromat beamline. These upgrades help us to measure the current and future Linac beam parameters, including the beam twiss parameters, energy, and energy spread. In this paper, we discussed how we could use these three BPMs for non-destructive energy measurement, which will be a part of the active energy correction system.
D. Rai, S.A. Baily, A.J. Braido, J.I. Duran, L.S. Kennel, H.L. Leffler, D. Martinez, L.S. Montoya, D.D. Zimmermann
LANL, Los Alamos, New Mexico, USA
Funding:Work supported by the U.S. Department of Energy, contract no. 89233218CNA000001. LA-UR-23-25123 The Los Alamos Neutron Science Center’s (LANSCE) Accelerator Operations and Technology division group executed a project that implemented a new analog front-end card (AFE) for their wire scanner’s Data Acquisition (DAQ) system. The AFE accommodates the signal amplification and noise reduction needed to acquire essential measurement data for beam diagnostics for the LANSCE accelerator. Wire Scanners are electro-mechanical beam interceptive devices that provide cross-sectional beam profile measurement data fitted to a Gaussian distribution that provides beam shape and position information. The beam operators use the beam shape and position information to adjust parameters such as acceleration, steering and focus on delivering an optimized beam to all targets. The project implemented software and hardware that eliminated the dependency on legacy systems and consolidated various AFE designs for diagnostics systems into a single design with 11 gain settings ranging from 100 nA to 40 mA at 10 V full scale to accommodate future applications on other diagnostic systems.
L.W. Lai, S.S. Cao, X.Q. Liu, Y.M. Zhou
SARI-CAS, Pudong, Shanghai, People’s Republic of China
J. Chen
SSRF, Shanghai, People’s Republic of China
R. Meng
SINAP, Shanghai, People’s Republic of China
Funding:Work supported by The National Science Foundation of China (Grant No.12175293). Youth Innovation Promotion Association, CAS (Grant No. 2019290) A RF direct sampling beam signal processor has been developed in SSRF. It mainly consists of four channels RF direct sampling ADCs and a SoC FPGA. The ADC is 9GHz bandwidth and 2.6GHz sampling rate. A prototype of RF module contains band pass filter, low noise ampli-fier and step attenuator has been designed for SHINE cavity BPM system. Then a novel cavity BPM electronic including the processor and the RF module has been built for SHINE. The performance of the electronic has been analyzed and evaluated in lab. The amplitude relative error is 2.0×10-4,which is better than the required 1×10-3 on cavity BPM system. The phase error is 14fs, also bet-ter than the requirement of RF BAM system. The algorithm and the implementation in FPGA have been introduced. Corresponding author: lailw@sari.ac.cn
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