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Production of high intensity electron bunches for the SLAC Linear Collide

Posted on:1989-12-11Degree:Ph.DType:Thesis
University:Stanford UniversityCandidate:James, Mary BethFull Text:PDF
GTID:2470390017456582Subject:High Energy Physics
Abstract/Summary:
This thesis describes the design and performance of a high intensity electron injector for the SLAC Linear Collider.;Motivation for the collider and the specifications for the injector are discussed. The specifications include: (1) Two electron bunches, approximately 59 nanoseconds apart, (2) For each bunch, eight nanocoulombs of charge captured in one accelerator RF cycle, (3) Bunch length and shape which result in a two percent energy spectrum at a beam energy of 1.2 GeV, (4) Invariant transverse emittance in both x- and y-planes no greater than 0.03 rad-cm.;An analytic theory of the bunching and capture of electrons by RF fields is discussed in the limit of low space charge and small signal. The design and performance of SLAC's main injector are described to illustrate a successful application of this theory. The bunching and capture of electrons by RF fields are then discussed in the limit of high space charge and large signal, and a description of the design of the collider injector follows.;In the limit of high space charge forces and large RF signals, the beam dynamics are considerably more complex and numerical simulations are required to predict particle motion. A computer code which models the longitudinal dynamics of electrons in the presence of space charge and RF fields is described.;The results of the simulations, the resulting collider injector design and the various components which make up the collider injector are described. These include the gun, subharmonic bunchers, traveling-wave buncher and velocity-of-light accelerator section. Finally, the performance of the injector is described including the beam intensity, bunch length, transverse emittance and energy spectrum.;While the final operating conditions differ somewhat from the design, the performance of the collider injector is in good agreement with the numerical simulations and meets all of the collider specifications.
Keywords/Search Tags:Injector, Collider, Intensity, Electron, Performance, RF fields, Bunch, Space charge
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