When talking about microwave/RF power system in Particle Accelerator, we usually refer to amplitude, phase and frequency stability as key indicators, whether these indicators are given by our self-made LLRF system or the results given by third-party standard measuring instruments. Not only that, when measuring some specific microwave parameters of the system, such as the QValue of the cavity,...
High Intensity heavy-ion Accelerator Facility (HIAF) is a major scientific and technological infrastructure project of the 12th Five Year Plan in China. It will be the heavy ion beam device with the highest pulse current intensity in the world. HIAF has the characteristics of fast ramping, high current and high energy. It puts forward high index requirements for the RF system of synchrotron....
BESSY-II synchrotron light source at Helmholtz Zentrum Berlin, has been in operation for almost 25 years and it is not expected that its successor, BESSY-III will be ready for user operation until the second half of the next decade. This fact makes necessary several modernization measures to keep BESSY-II competitive until then. One of these measures is the replacement of the old analogue LLRF...
The ISIS buncher system at TRIUMF operates at frequencies of 23MHz, 46MHz, and 4.6MHz. The 23MHz and 46MHz signals drive two buncher cavities, while the 4.6MHz signal drives the 5:1 selector. The previous analog-digital hybrid system has been replaced with a new digital LLRF system due to occasional drifts in the setpoints of the control loops during operation. The reference signal for the...
Controlling SRF cavities in CW mode in the presence of mechanical disturbances, as well as in the presence of noisy detectors, makes control still a challenge. Internal cavity features such as Lorentzian forces are well understood and predictable, but also make control difficult. An inexpensive solution for compact accelerators that can accommodate many algorithms simultaneously on a single...
An analog crystal filter based cavity emulator is modified with reverse biased varactor diodes to provide a tuning range of around 100 Hz. The piezo drive voltage of the resonance controller is used to detune the cavity through the bias voltage. A signal conditioning and summing circuit allows the introduction of microphonics disturbance from a signal source or using real microphonics data...
The LLRF system for the Mu2e project uses the same primary LLRF hardware as the Muon g-2 experiment that has been running for the past five years. The SSA and RF cavity for the capture of the 2.5 MHz beam bunches in the delivery ring are located about a mile away from the LLRF controller. A local FPGA controller chassis is used to digitize the cavity signals and to co-ordinate the beam...
The J-PARC Main Ring (MR) is a high intensity proton synchrotron that accelerates protons from 3 GeV to 30 GeV. Its output beam power for fast extraction reached 515 kW, corresponding to $2.66\times10^{14}$ protons per pulse, in April 2021, and studies and hardware upgrades are underway to achieve higher beam intensities. We observed longitudinal coupled bunch instabilities (CBI) above 450 kW...
DCLS (Dalian Coherent Light Source) is an FEL (Free-Electron Laser) user facility at EUV (Extreme Ultraviolet). The primary accelerator of DCLS operates at a repetition rate of 20 Hz, and the beam is divided at the end of the linear accelerator through Kicker to make two 10 Hz beamlines work simultaneously. In the past year, we have completed the upgrade of the DCLS LLRF (Low-Level...
In FEL (Free-Electron Laser) accelerators, LLRF (Low-Level Radiofrequency) systems usually deploy feedback or feedforward algorithms requiring precise microwave measurement. The slow drift of the clock allocation network of LLRF significantly impacts the measured microwave phase, thereby affecting the stability of the closed-loop operation. The reference tracking algorithm is used to eliminate...
As part of the modernization of the Los Alamos Neutron Science Center (LANSCE), a digital low level RF (DLLRF) control system for the 16.67 MHz Low frequency buncher (LFB) is designed and is implemented on a Field Programmable Gate Array (FPGA). In this paper, the newly designed DLLRF control system of the LANSCE LFB and its performance verified on the cavity simulator are addressed....
The CERN Linac4 accelerator, completed in 2017, achieved a significant milestone when it was connected to the Proton Synchrotron Booster (PSB) in December 2020, enhancing its operational capabilities. This paper provides an overview of Linac4's parameters and RF layout, emphasizing key aspects of its design. It focuses on the identification and resolution of operational issues encountered...
The upgrade plan of the China Spallation Neutron Source aims to enhance the beam power from 100 kW to 500 kW. To achieve this, the plan involves incorporating three new magnetic alloy cavities while maintaining the existing system to enable double harmonic acceleration. As a consequence of the increased current intensity, the beam loading effect will be significantly amplified in multiple...
A 300 MeV proton and heavy ion accelerator complex has been designed and constructed by the Institute of Modern Physics for the space environment simulation and research infrastructure (SESRI) project. The linac injector of the accelerator complex is based on normal-conducting rf structures. It consists of an RFQ, a buncher, three DTLs, and two debunchers. The requirements for the rf field...
The first version of digital low level RF (DLLRF) for the Diamond Light Source storage ring and booster was developed with ALBA Synchrotron. Six systems have been built so far. Two of them are in routine operation controlling two normal conducting HOM-damped cavities in the Diamond storage ring. A third system is being used for cavity testing in the RF test facility. The fourth system has...
The SNS RFTF is used for RF conditioning to prepare RF structures such as ceramic windows and couplers for charged-particle accelerator installation and operation, involving high-power RF fields and heating to improve performance and remove impurities. A Python-based EPICS control system software and some hardware updates were developed to automate and optimize the conditioning process, with...
The CAFe II is upgraded from Chinese ADS Front-end demo facility, it’s a superconducting radio frequency(SCRF) linac to accelerate the proton or heavy ion for nuclear physics research. The facility aims to synthetic superheavy elements which demand high beam availability, therefore, the new fast RF interlock system has been developed to meet the reliability requirements for long-term operation...
Vertical test stands(VTS) and cryomodule test facilities(HTF) have been built in SHINE cryomodule assembly and test hall(ATH). 633 TESLA type super conducting cavities and 75 cryomodules should be tested on these test stands. RF measurement and some result will be shown.
The LLRF of four of TRIUMF's ISAC-1 accelerator cavities have been replaced by 2 FPGA based system. These are 2 Drift Tube Linacs and 2 bunchers, nameley DTL4, DTL5, HEBT11 and HEBT35. The operating frequencies of these cavities 11.76 MHz, 35.36 MHz for the bunchers and 106.08 MHz for the DTLS, with the RF power ranges from 1.5 kW and 13 kW for the 2 bunchers to more than 20 kW for the DTLs....
Within the framework of the first phase of MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) project, as known as MINERVA, IJCLab was assigned with the development of a fully functional Spoke cryomodule prototype development,which was tested at 2K. This prototype integrates two superconducting single spoke cavities, the RF power couplers and the Cold Tuning Systems...
The PIP-II project is an international collaboration with various subsystems developed by partner labs. The LLRF and RFPI systems developed at BARC are being tested with cold cavities at the Fermilab STC facility. Complete systems for the 325 MHz and 650 MHz cavities will be tested and validated. The test results and performance of these systems are presented.
The Computer Automated Measurement and Control (CAMAC) system is a modular instrumentation bus that was originally developed in the 1970s and is widely used for the LLRF control of C20/C50 Cryomodule at JLab. Due to the serial bus limitations, real time analysis of RF control signals is severely inhibited. To address this, a new Artix FPGA based Data Acquisition Chassis has been developed and...
Precise measurements of the cavity forward (Vf) and reflected signals (Vr) are essential for characterizing other key parameters such as the cavity detuning and forward power. In practice, the accuracy of these measurements is impacted by the crosstalk between the forward and reflected channels. DESY proposed an algorithm for calibrating Vf and Vr based on the cavity differential equation for...
In the long-term project frame of the HIPA (High Intensity Proton Accelerator) RF systems, the replacement of analogue LLRF from the decades 1980 with a digital system is ongoing.
This new digital LLRF system will be used the first time in HIPA for beam operation with a new cavity in autumn 2023.
The tuning system, with hydraulic aggregate and valve actor for the plunger, is working in...
The mathematical model of a RF system incorporates crucial characteristic parameters of the RF cavity, including cavity bandwidth, resonant frequency, and LFD factors. This mathematical model is crucial for cavity performance evaluation and optimization of control algorithms. The network analyzer is usually used for measuring the scattering parameters of the RF system and subsequently...
The existing bunch length monitoring system was designed and installed more than thirty years ago. This system measures the beam induced signal from a 5.988 GHz cavity. This phase is compared to a reference signal using a double balanced mixer/phase detector. The data are acquired using a Computer Automated Measurement and Control (CAMAC) system for bunch length determination and analysis....
A 100-MeV proton accelerator has been developed, and the beam service started at the Korea Multi-purpose Accelerator Complex (KOMAC) in July 2013. The accelerator consists of a 50-keV proton injector, a 3-MeV radio-frequency quadrupole (RFQ) and a 100-MeV drift tube linacs (DTLs). Total 9 pulsed klystrons with 1.6 MWpeak are used to provide RF power to the cavities with 350 MHz of operating...
The new RF phase reference generation system was designed and installed to ensure proper and reliable operation of the linac upgraded in the FLASH2020+ program. It synthesizes ultra-stable and ultra-low phase noise RF signals at 9, 108, 1300, and 1517 MHz frequencies. These signals are then routed via coaxial cables to all the system endpoints along the linac. This task required the...
SPARC_LAB is a high-brightness photoinjector developed for FEL and research on novel acceleration techniques. It has been in operation at LNF since 2005. It is made of a newly designed brazeless 1.6-cell S-band RF gun, two SLAC type S-band and one C-band accelerating structures. Recently, a plasma chamber was installed to study beam-driven plasma acceleration schemes.
During fall 2023, a...
