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.
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
X.H. Tang, J.S. Cao, Y.Y. Du, J. He, Y.F. Sui, J.H. Yue
IHEP, Beijing, People’s Republic of China
Determining the mechanical center of the beam position monitor(BPM) has been a difficulty for BPM calibration. To solve this problem, a method of positioning the BPM mechanical center based on laser ranging is proposed. This method uses high-precision antenna support as the core locating datum, and high-precision laser ranging sensors(LRSs) as the detection tool. By detecting the distances from the LRSs to the antenna support and the distances from the LRSs to the BPM, the mechanical center of the BPM can be indirectly determined. The theoretical system error of this method is within 20¿m, and the experimental results show that the measurement repeatability is less than 40¿m, This method has low cost and fast speed, which can be used for large-scale calibration.
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.
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.
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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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
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.
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.
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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