Conveners
Synchronization: Synchronization I
- John David Fox
Synchronization: Synchronization II
- Luca Piersanti (Istituto Nazionale di Fisica Nucleare)
Synchronization: Synchronization III
- Zeran Zhou (University of Science and Technology of China)
Synchronization: Synchronization IV
- Alessandro Ratti
Distribution systems are used to provide reference frequencies from a common source to all phase-critical clients at an accelerator. To precisely synchronize remote RF and optical oscillators to the common clock, a combination of phase-stabilized links and phase-locked loops with optimized bandwidth and locking parameters are implemented. A pre-requisite to reach the required phase-stability,...
To explore the implementation of laser-RF synchronization with femtosecond-level precision and stability, we proposed and demonstrated a Sagnac loop-based all-fiber optical-microwave phase detector (AFOM-PD). The repetition rate of the reference laser is 29.134 MHz, and its RIN has been suppressed by 40 dB at 1 Hz offset frequency. A 1.311010 GHz (2.855132 GHz) RF signal was synchronized with...
The Compact Linear Accelerator for Research and Applications (CLARA) is a 250 MeV ultrabright beam test facility at STFC Daresbury Laboratory. Originally conceived as a free electron laser test facility, timing is based on an actively stabilised optical timing architecture, incorporating optoelectronic systems for beam arrival diagnostics and laser/RF client synchronisation. The facility is...
The Phase Reference Line (PRL) of the European Spallation Source (ESS) is a passive system based on a single 1-5/8” coaxial rigid line installed at the tunnel ceiling above the beamline. It is supported by temperature and gas pressure control systems with active electronics installed in the ESS Klystron Gallery Hall. The length of the PRL is around 580 meters. The system is temperature...
The PIP-II Accelerator is an 800 MeV superconducting Linac in the injection chain of the Fermilab accelerator complex. The LLRF systems for the 125 cavities which include a few normal conducting cavities in the warm front-end section, use a variety of LLRF hardware components and sub-systems that are part of the timing and synchronization system. This includes a master oscillator and phase...
In 2023, LINAC Coherent Light Source II achieved first light, spanning over 5 km from injector to the experiment hall. The goal of achieving 10fs relative jitter between the experiment laser and the x-ray led to the development of new systems. We will present the timing system design, architecture, key commission results and challenges along the way.
The challenge of reference distribution in...
New experiments and particle accelerator R&D programs at LNF are pushing the requests on beam stability and reliability towards the limit of the present technology. This drives the study on timing (event management and trigger distribution, down to ps scale) and synchronization (high frequency reference signal generation and distribution, down to fs scale). This presentation will give an...
Recent advances of plasma-based accelerators showed the feasibility to generate multi GV/m gradients for ultra-short electron bunches to be used for user-oriented applications. The shot-to-shot stability of the plasma-accelerated beam is of fundamental importance and represents the last gap to fill to fully compete with state-of-the-art radio-frequency accelerators. In this context we discuss...
With the invention of the frequency comb two decades ago it became possible to easily (and phase coherently) switch between radio and microwave frequencies in the GHz to 10s of GHz range and optical frequencies in the range of several 100 THz.
The much faster oscillations of optical frequencies give us a few orders of magnitude advantage whenever it comes to interferometric...
Free electron laser has the characteristics of extremely high peak brightness, ultra-short pulse and high coherence, providing unprecedented research opportunity for physics, chemistry, biomedicine, materials science and energy science.
Large-scale free electron laser and its time-resolved pump-probe experiment requires femtosecond-level synchronization. Optical and RF synchronization...
State of the art Free Electron Lasers have rigorous electron beam stability requirements. To fulfill these requirements the low-level RF systems rely on a phase stable RF reference. Classical coaxial RF distribution systems have low complexity and thus offer excellent reliability and also a good short-term performance. However, their long-term stability does not meet today's requirements of...
HEPS is a new built 6GeV 4th-gen synchrotron radiation light source and under beam commissioning right now. The phase distribution system includes master oscillator system and phase reference line system. The DDS-based MO generates 499.8MHz and 166.6MHz, then distributes to Linac, booster RF and storage ring RF, beam station, as well as BI electronics clock around the facility. The 499.8MHz...
This contribution, planned as a sort of short summary/tutorial, will cover the basics of RF synchronization, starting with theoretical definitions and an attempt to put together and organize concepts and names frequently confused by various people. Items such as the definition of synchronization systems and their accuracy measures will be discussed, followed by sources of instabilities and...