A Design and Performance Analysis Tool for Superconducting RF Systems PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A Design and Performance Analysis Tool for Superconducting RF Systems PDF full book. Access full book title A Design and Performance Analysis Tool for Superconducting RF Systems by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Superconducting rf systems are usually operated with continuous rf power or with rf pulse lengths exceeding 1 ms to maximize the overall wall plug power efficiency. Typical examples are CEBAF at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the TESLA Test Facility at DESY. The long pulses allow for effective application of feedback to stabilize the accelerating field in presence of microphonics, Lorentz force detuning, and fluctuations of the beam current. In this paper the authors describe a set of tools to be used with MATLAB and SIMULINK, which allow to analyze the quality of field regulation for a given design. The tools include models for the cavities, the rf power source, the beam, sources of field perturbations, and the rf feedback system. The rf control relevant electrical and mechanical characteristics of the cavity are described in form of time-varying state space models. The power source is modeled as a current generator and includes saturation characteristics and noise. An arbitrary time structure can be imposed on the beam current to reflect a macro-pulse structure and bunch charge fluctuations. For rf feedback several schemes can be selected: Traditional amplitude and phase control as well as I/Q control. The choices for the feedback controller include analog or digital approaches and various choices of frequency response. Feed forward can be added to further suppress repetitive errors. The results of a performance analysis of the CEBAF and the TESLA Linac rf system using these tools are presented.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Superconducting rf systems are usually operated with continuous rf power or with rf pulse lengths exceeding 1 ms to maximize the overall wall plug power efficiency. Typical examples are CEBAF at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the TESLA Test Facility at DESY. The long pulses allow for effective application of feedback to stabilize the accelerating field in presence of microphonics, Lorentz force detuning, and fluctuations of the beam current. In this paper the authors describe a set of tools to be used with MATLAB and SIMULINK, which allow to analyze the quality of field regulation for a given design. The tools include models for the cavities, the rf power source, the beam, sources of field perturbations, and the rf feedback system. The rf control relevant electrical and mechanical characteristics of the cavity are described in form of time-varying state space models. The power source is modeled as a current generator and includes saturation characteristics and noise. An arbitrary time structure can be imposed on the beam current to reflect a macro-pulse structure and bunch charge fluctuations. For rf feedback several schemes can be selected: Traditional amplitude and phase control as well as I/Q control. The choices for the feedback controller include analog or digital approaches and various choices of frequency response. Feed forward can be added to further suppress repetitive errors. The results of a performance analysis of the CEBAF and the TESLA Linac rf system using these tools are presented.
Author: Martin Comyn
Publisher:
ISBN:
Category : Nuclear engineering
Languages : en
Pages : 1382
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Get Book Here
Book Description
Author: Bart J. Diaz
Publisher:
ISBN:
Category : Electric generators
Languages : en
Pages : 274
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 260
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 844
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 782
Get Book Here
Book Description
Author: Aaron McKeown
Publisher:
ISBN: 9781085572132
Category : Nuclear physics
Languages : en
Pages : 76
Get Book Here
Book Description
The SRF conduction link project at Fermi National Accelerator Laboratory aims to develop an SRF particle accelerator design that is more applicable for industrial use. Collaboration between NIU college of engineering and NIU department of physics provided the bulk of design and analysis for this project. Currently, cooling systems, used in SRF particle accelerators, pump liquid helium across the SRF cavity to provide convection based cooling. The goal of this project is to incorporate a conduction based cooling system. In a conduction based cooling system, heat will flow from the SRF cavity into a cryocooler through a conduction link. In addition, this particle accelerator design incorporates field emission via a cathode mounted within the cavity. Due to the significant effect of cathode placement on the emission characteristics of the cathode, a mounting component called the cathode rod will position the cathode in an optimal location. Steady state finite element thermal simulations and radio frequency electromagnetic simulations were performed in order to determine the dissipated power and operating temperature of the cavity components at various rod length configurations. Since the SRF cavity components must remain superconductive during operation, the temperature must remain below the superconductive threshold. Thermal simulation results indicated that an increase in length of the cathode rod corresponded to an increase in maximum operating temperature. A compromise between the cathode position and the maximum operating temperature of the cathode mountresulted in the selection of an optimal cathode mount length. The results of the analysis influenced the design of the conduction link and cathode mount prior to fabrication, installation, and testing.
Author: Themistoklis Mastoridis
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 216
Get Book Here
Book Description
The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC. Simulations studies and measurements were conducted that clearly show the correlation between RF noise and longitudinal bunch emittance, identify the major LLRF noise contributions, and determine the RF component dominating this effect. With these results, LHC upgrades and alternative algorithms are evaluated to reduce longitudinal emittance growth during operations. The applications of this work are described with regard to future machines and analysis of new technical implementations, as well as to possible future work which would continue the directions of this dissertation.
Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 408
Get Book Here
Book Description
