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. 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.
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.
R.T. Keane, K.C. Harkay, N. Sereno
ANL, Lemont, Illinois, USA
A. Caracappa, C. Danneil, K. Ha, J. Mead, D. Padrazo
BNL, Upton, New York, USA
Funding:Work supported by U. S. Department of Energy Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 The Advanced Photon Source upgrade (APS-U) Multi-Bend Acromat (MBA) storage ring utilizes on-axis swap-out injection requiring up to 20nC charge per electron bunch. Enforcement of radiation safety limits for the new storage ring will be accomplished by a new beam charge monitor interlock that accumulates beam charge measurements in the Booster-to-Storage ring (BTS) transfer line and disables injection when the charge limit over a preset time period is exceeded. The new interlock is based on the existing APS Beam Shut-Off Current Monitor (BESOCM), and incorporates significant improvements over the existing system. New features include use of direct digitization and FPGA processing, extensive remote monitoring capabilities, expanded self-test and fail-safe functions, and the ability to adjust settings and monitor status remotely via EPICS. The new device integrates a test pulse (self-check) feature that verifies the integrity of the integrating beam current transformer (ICT) and cable system used to detect the beam signal. This paper describes the new BTS interlock (BESOCM) design and presents results of bench test and in-machine evaluation of the prototype and production units.
D. Belohrad
European Organization for Nuclear Research (CERN), Geneva, Switzerland
J. Emery, J.C. Esteban Felipe, A. Goldblatt, A. Guerrero, M. Martin Nieto, F. Roncarolo
CERN, Meyrin, Switzerland
Between 2019 and 2023, as part of the LHC Injectors Upgrade (LIU), a major renovation of the CERN wire scanners (BWS) was performed. The main driving force was to prepare the wire scanners for the High-Luminosity LHC (HL-LHC), during which the instantaneous luminosity is expected to double, to around 5× 1034cm-2s-1. In 2021 seventeen LIU BWSs were installed in the CERN PS complex and the SPS. Additionally, two BWSs were installed in the LHC, at the end of 2022, to be ready for the 2023 LHC run. The aim of the contribution is to describe in detail the technical implementation of the digital signal acquisition (DAQ) and data processing of the newly installed BWSs. Particular attention is given to the design of the analogue front-end, signal conversion, and data processing chain ¿ providing raw data for the profile reconstruction. The synchronisation of the incoming digitised signal with the machine timing is also a focus point, as it differs significantly between the PS complex on the one hand and the LHC and SPS on the other hand. In conclusion we present beam measurements, and discuss the limitations of the algorithms used.
R.Z. Wu, P. Lu, B.G. Sun, L.L. Tang, D.Y. Wang, Y.K. Zhao
USTC/NSRL, Hefei, Anhui, People’s Republic of China
The decrease of beam emittance in the 4th generation light source greatly increases the electron density, thus the wakefields and beam impedance in the storage ring are significantly enhanced, resulting in various beam instabilities. Therefore, it is necessary to observe the transient state of beams using the bunch-by-bunch technique, so as to dig into these instabilities. Here a three-dimensional (3D) positions measurement instrument is designed based on data synchronization module (DSM) to acquire the transverse positions and longitudinal phases of beams in real-time.
M. Kuntzsch, M. Justus, A. Schwarz, K. Zenker
HZDR, Dresden, Germany
L. Krmpotić, U. Legat, Z. Oven, L. Perusko, U. Rojec
Cosylab, Ljubljana, Slovenia
The CW electron accelerator ELBE is in operation for more than two decades. The timing system has been patched several times in order to meet changing requirements. In 2019 the development of a new timing system based on Micro Research Finland Hardware has been started which is designed to unify the heterogeneous structure and to replace obsolete components. In spring 2023 the development of the software has been accomplished, which included the mapping of operation mode and different complex beam patterns onto the capabilities of the commercial platform. The system generates complex beam patterns from single pulse, to macro pulse and 26 MHz cw operation including special triggers for diagnostics and machine subsystems. The contribution will describe the path from requirements to development and commissioning of the new timing system at ELBE.
C. Bianchini Mattison, K.H. Kim, P. Krejcik, M. Weaver, S. Zelazny
SLAC, Menlo Park, California, USA
The new timing system for the LCLS-II SC linac and FEL meets the challenging requirements for delivering multiple interleaved timing patterns to a number of different destinations at rates up to 1 MHz. The timing patterns also carry information on bunch charge and beam energy to prevent inadvertent selection of beam dumps beyond their rated beam power. Beamline instruments are equipped with a timing receiver that performs bunch-by-bunch synchronous data acquisition based on the timing pattern for that location. Data is buffered in on-board memory for up to 106 machine pulses (1 second at 1 MHz). The large data volume can be locally processed and and analysed before transmission to clients on the network. Commissioning and experience with the new system will be presented.
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