RF Properties of Periodic Accelerating Structures for Linear Colliders PDF Download

Author: J. W. Wang
Publisher:
ISBN:
Category : Linear accelerators
Languages : en
Pages : 336

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Author:
Publisher:
ISBN:
Category : Linear accelerators
Languages : en
Pages :

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Book Description
With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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The next linear collider will require 200 MW of rf power per meter of linac structure at relatively high frequency to produce an accelerating gradient of about 100 MV/m. The higher frequencies result in a higher breakdown threshold in the accelerating structure hence permit higher accelerating gradients per meter of linac. The lower frequencies have the advantage that high peak power rf sources can be realized. 11.42 GHz appears to be a good compromise and the effort at the Stanford Linear Accelerator Center (SLAC) is being concentrated on rf sources operating at this frequency. The filling time of the accelerating structure for each rf feed is expected to be about 80 ns. Under serious consideration at SLAC is a conventional klystron followed by a multistage rf pulse compression system, and the Crossed-Field Amplifier. These are discussed in this paper.

Author: H. H. Braun
Publisher:
ISBN:
Category : Colliders (Nuclear physics)
Languages : en
Pages : 212

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Author: Richard Clinton Fernow
Publisher:
ISBN:
Category : Klystrons
Languages : en
Pages : 440

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Author: P Eerola
Publisher: World Scientific
ISBN: 9814554596
Category :
Languages : en
Pages : 876

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This workshop brought together for the first time accelerator experts as well as experimental and theoretical high energy physicists from all over the world to consider the physics potential of high energy linear electron-positron colliders. A wide variety of physics cases were presented ranging from precision tests of the top quark and electroweak gauge bosons to searches of the intermediate mass Higgs bosons and supersymmetric particles.

Author:
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Category :
Languages : en
Pages :

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Modern microfabrication techniques based on deep etch x-ray lithography (LIGA) can be used to produce large-aspect-ratio, metallic or dielectric, planar structures suitable for high-frequency RF acceleration of charged particle beams. Specifically, these techniques offer significant advantages over conventional manufacturing methods for future linear colliders (beyond NLC, the Next Linear Collider) because of several unique systems requirements. First, to have the required ac ''wall plug'' power within reasonable limits, such future linear colliders (≥ 5TeV) must operate at high frequency (≥ 30GHz). This implies the need of a large number of intricate accelerating structures with ever smaller dimensions and extremely tight manufacturing tolerances, imposing new challenges in mass-production, precision fabrication techniques. Microfabrication is particularly suitable for meeting this need. Secondly, luminosity requirements suggest the use of multi-bunch acceleration of electrons and positrons in the linear collider. In order for these schemes to accelerate low-emittance beams over a long distance, it is important that the wakefield effects be reduced to a minimum in the accelerating structure. Asymmetric planar structures have more geometric degrees of freedom than cylindrically symmetric structures. In addition to detuning, these can be utilized to further reduce the wakefields. Thirdly, in order to clearly discriminate physics events in the final interaction point at which electrons and positrons collide, it is required that secondary particle production from beamstrahlung be minimized. Flat electron and positron beams with a large aspect ratio will be beneficial in reducing beamstrahlung in the final focus region, but cause the beam to be more sensitive to wakefields in the vertical dimension. In principle, a flat beam can be accelerated in a planar structure with reduced wakefield in the vertical direction for the entire length of the accelerator.

Author: Thomas P. Wangler
Publisher: John Wiley & Sons
ISBN: 9783527406807
Category : Science
Languages : en
Pages : 476

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Book Description
Dieses einschlägige Lehrbuch, entwickelt auf der Grundlage der Ausbildung an der US Particle Accelerator School, schließt eine Lücke in der verfügbaren Literatur zum Thema Hochfrequenz-Linearbeschleuniger, kurz RF-Linac. Nach einer Erläuterung der naturwissenschaftlichen Grundlagen und der neuesten technologischen Eckdaten stellt diese zweite Auflage neueste RF-Linacs, spezialisierte Systeme, Systeme mit Supraleitern und verschiedene Spezialverfahren vor. Übungsaufgaben an den Kapitelenden erleichtern das Einprägen und das Nacharbeiten von Vorlesungen.

Author: Melvin Month
Publisher: World Scientific
ISBN: 9814578274
Category :
Languages : en
Pages : 875

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The motivation to conceive and build accelerators comes from a most fundamental need of man — to understand and control the world around us. With beams and their associated accelerators, scientists and engineers can gain understanding of the nature of matter and modify matter, which is not possible by other means. The areas already influenced by the developments in accelerator technology are high energy and nuclear physics, atomic and molecular physics, condensed matter physics and the biological sciences. There are also a growing number of applications in medicine and industry.This book summarizes all the currently available knowledge on the rf technology driving the development of particle beams for science, medicine and industry. It is a unique collection of information on this technology.

Author: Ursula van Rienen
Publisher: Springer Science & Business Media
ISBN: 3642568025
Category : Computers
Languages : en
Pages : 387

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treated in more detail. They are just specimen of larger classes of schemes. Es sentially, we have to distinguish between semi-analytical methods, discretiza tion methods, and lumped circuit models. The semi-analytical methods and the discretization methods start directly from Maxwell's equations. Semi-analytical methods are concentrated on the analytical level: They use a computer only to evaluate expressions and to solve resulting linear algebraic problems. The best known semi-analytical methods are the mode matching method, which is described in subsection 2. 1, the method of integral equations, and the method of moments. In the method of integral equations, the given boundary value problem is transformed into an integral equation with the aid of a suitable Greens' function. In the method of moments, which includes the mode matching method as a special case, the solution function is represented by a linear combination of appropriately weighted basis func tions. The treatment of complex geometrical structures is very difficult for these methods or only possible after geometric simplifications: In the method of integral equations, the Greens function has to satisfy the boundary condi tions. In the mode matching method, it must be possible to decompose the domain into subdomains in which the problem can be solved analytically, thus allowing to find the basis functions. Nevertheless, there are some ap plications for which the semi-analytic methods are the best suited solution methods. For example, an application from accelerator physics used the mode matching technique (see subsection 5. 4).