Commissioning of the LCLS-II Machine Protection System for MHz CW Beams
154
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.
FPGA Architectures for Distributed ML Systems for Real-Time Beam Loss De-Blending
160
M.A. Ibrahim, J.M.S. Arnold, M.R. Austin, J.R. Berlioz, P.M. Hanlet, K.J. Hazelwood, J. Mitrevski, V.P. Nagaslaev, A. Narayanan, D.J. Nicklaus, G. Pradhan, A.L. Saewert, B.A. Schupbach, K. Seiya, R.M. Thurman-Keup, N.V. Tran
Fermilab, Batavia, Illinois, USA
J.YC. Hu, J. Jiang, H. Liu, S. Memik, R. Shi, A.M. Shuping, M. Thieme, C. Xu
Northwestern University, EVANSTON, USA
Funding:Operated by Fermi Research Alliance, LLC under Contract No.DE-AC02-07CH11359 with the United States Department of Energy. Additional funding provided by Grant Award No. LAB 20-2261 [1] The Real-time Edge AI for Distributed Systems (READS) project’s goal is to create a Machine Learning (ML) system for real-time beam loss de-blending within the accelerator enclosure, which houses two accelerators: the Main Injector (MI) and the Recycler (RR). In periods of joint operation, when both machines contain high intensity beam, radiative beam losses from MI and RR overlap on the enclosure¿s beam loss monitoring (BLM) system, making it difficult to attribute those losses to a single machine. Incorrect diagnoses result in unnecessary downtime that incurs both financial and experimental cost. The ML system will automatically disentangle each machine¿s contributions to those measured losses, while not disrupting the existing operations-critical functions of the BLM system. Within this paper, the ML models, used for learning both local and global machine signatures and producing high quality inferences based on raw BLM loss measurements, will only be discussed at a high-level. This paper will focus on the evolution of the architecture, which provided the high-frequency, low-latency collection of synchronized data streams to make real-time inferences. Performed at Northwestern with support from the Departments of Computer Science and Electrical and Computer Engineering
Collimator Scan Based Beam Halo Measurements in LHC and HL-LHC
164
P.D. Hermes, M. Giovannozzi, C.E. Montanari, S. Morales Vigo, S. Redaelli, B. Salvachúa
CERN, Meyrin, Switzerland
M. Rakic
EPFL, Lausanne, Switzerland
Measurements in the CERN Large Hadron Collider (LHC) have indicated that the population of the transverse beam halo is greater than that of a Gaussian distribution. With the upcoming High Luminosity upgrade (HL-LHC), the stored beam energy in the beam halo could become large enough to threaten the integrity of the collimation system. Considerable efforts during the ongoing LHC Run 3 are dedicated to characterising the transverse beam halo, and its diffusion properties, after the LHC Injector Upgrade (LIU) in preparation for HL-LHC operation. Given the unprecedented stored beam energies of about 400MJ, presently achieved at the LHC, and about 700MJ planned at the HL-LHC, conventional measurements are difficult. Halo and diffusion measurements are currently based on collimator scans, where robust collimators are inserted in steps into the circulating beam halo. In this contribution, we present techniques for halo characterisation employed in LHC and compare results obtained from such measurements in LHC Run 2 and the ongoing LHC Run 3. We present plans for measurements in the remainder of LHC Run 3 and describe expected challenges for halo quantification in HL-LHC.
Comparison of Different Bunch Charge Monitors Used at the ARES Accelerator at DESY
169
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.
Low Intensity Beam Current Measurement of the Associated Proton Beam Line at CSNS
174
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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