Open AccessDOI
The LCLS-II LLRF System
Lawrence Doolittle,Gang Huang,Alex Ratti,Carlos Serrano,Ramakrishna Bachimanchi,J. Curt Hovater,Sandeep Babel,Bo Hong,D. Van Winkle,Brian Chase,Ed Cullerton,Philip Varghese +11 more
- pp 1195-1197
TLDR
The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW superconducting (SCRF) linac.Abstract:
The SLAC National Accelerator Laboratory is planning an upgrade (LCLS-II) to the Linear Coherent Light Source with a 4 GeV CW superconducting (SCRF) linac. The SCRF linac consists of 35 ILC style cryomodules (eight cavities each) for a total of 280 cavities. Expected cavity gradients are 16 MV/m with a loaded QL of ~ 4x107. The RF system will have 3.8 kW solid state amplifiers driving single cavities. To ensure optimum field stability a single source single cavity control system has been chosen. It consists of a precision four channel cavity receiver and RF stations (Forward, Reflected and Drive signals). In order to regulate the resonant frequency variations of the cavities due to He pressure, the tuning of each cavity is controlled by a Piezo actuator and a slow stepper motor. In addition the system (LLRF-amplifier-cavity) is being modeled and cavity microphonic testing has started. This paper describes the LLRF system under consideration, including recent modeling and cavity tests.read more
Citations
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Journal ArticleDOI
Superconducting Cavity Control and Model Identification Based on Active Disturbance Rejection Control
TL;DR: In this article, an active disturbance rejection control (ADRC) was designed for superconducting cavities counting the Lorenz force detuning and beam loading as disturbances to the cavities.
Dissertation
Cavity Field Control for Linear Particle Accelerators
TL;DR: This thesis demonstrates that a key to understand the dynamics of the field control loop is to represent it as a single-input single-output system with complex coefficients, and develops practical and theoretical tools for analysis and control design for complex-coefficient systems.
Journal ArticleDOI
Laser–RF synchronization based on digital phase detector
Jin Yang,Yingchao Du,Lixin Yan,Gang Huang,Qiang Du,Yilun Xu,Yilun Xu,Wenhui Huang,Huaibi Chen +8 more
TL;DR: The digital phase detector is implemented in the synchronization scheme for less noise, replacing the mixing to DC phase detection scheme, and a laser oscillator emulator was developed for phase locking.
High Precision RF Control for the LCLS-II
Gang Huang,Sandeep Babel,Ramakrishna Bachimanchi,Matt Boyes,Garth Brown,Kerri Campbell,David Nam Sul Cha,Brian Chase,Ed Cullerton,Lawrence Doolittle,Qiang Du,Joshua Einstein,Bo Hong,Curt Hovater,John G. Jones,Daniel Klepec,Alessandro Ratti,Claudio Rivetta,David N. Seidman,Carlos Serrano,Vamsi Vytla +20 more
TL;DR: The LCLS-II project as discussed by the authors is a CW superconducting linac under construction to drive an X-ray FEL, which requires electron beam jitter and energy spread better then 20 fs and 0.014% at the undulator to achieve its X-Ray beam quality goals.
Dissertation
Cavity Field Control for High-Intensity Linear Proton Accelerators
TL;DR: In this article, the authors present a non-standard parametrization and derivation of the cavity field dynamics that make it easier to relate the physical cavity process to the model, and simplifies the understanding of how the cavity parameters affect the achievable control performance.
References
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ReportDOI
The RF Phase Distribution and Timing System for the NLC
TL;DR: In this article, a prototype fiber optic distribution system has been constructed to demonstrate this level of performance, which operates by measuring the optical round trip time in the fiber, and then controlling the fiber phase length to stabilize this measurement.
Commissioning and operation of the cebaf 100 mv cryomodules
Trent Allison,Gary L. Davis,Michael Drury,Leigh H. Harwood,J. Hogan,Andrew Kimber,George Lahti,William Merz,Richard Nelson,Tomasz Plawski,David Seidman,Michael Spata,Michael Wilson,J. Hovater +13 more
TL;DR: In this article, the authors report on the commissioning and operation of the RF system and cryomodules in the CEBAF accelerator, which is used for nuclear physics experiments.
LLRF Design for the HINS-SRF Test Facility at Fermilab
TL;DR: In this paper, a real-time measurement of the cavity loaded Q and Q0 is implemented using gradient decay techniques, allowing for Q0 versus Eacc plots, and a real time cavity simulator is also developed to test the LLRF system and verify its functionality.
Llrf control for spx @ aps demonstration experiment
TL;DR: The hardware and firmware design of the demonstration experiment including the cavity emulator, LO and reference reference generation, receiver chassis, and LLRF control algorithm are discussed.