Frequency control in wake field waveguide structures

Перспективные Технологии Для Прикладных Резонансных Ускорителей Заряженных Частиц И Примеры Их Использования (Обзор)

“…Привлекательной альтернативой медным структурам для компактных ускорителей являются диэлектрические структуры, в которых гладкий металлический волновод частично заполнен диэлектриком (DLA) [217,218]. Действительно, длина волны в такой структуре будет пропорциональна ε −1/2 .…”

New Low-Loss Ferroelectric Materials for Accelerator Applications

“…In a DLA structure, these errors can be caused by machining tolerance of the dielectric dimensions and dielectric constant heterogeneity. The tuning method used to vary the frequency of a DLA structure consists of a thin layer of a ferroelectric material backing a layer of conventional ceramic [18]. A DC bias voltage is used to vary the permittivity of the ferroelectric layer and thus tune the overall frequency of the DLA structure.…”

“…A DC bias voltage is used to vary the permittivity of the ferroelectric layer and thus tune the overall frequency of the DLA structure. A detailed design for this device has been developed and an experimental test has been proposed and demonstrated [17,18]. The ferroelectric materials described above are ideal for use in tunable DLAs.…”

“…Lack of frequency control also causes problems for multistage accelerators where one has to match the accelerating field frequency and phase between adjoining sections. A method to vary the resonant frequency of a DLA structure [17,18] by an electrically-controlled thin layer of ferroelectric has been demonstrated [19].…”

Development of a Tunable Dielectric Loaded Acceleration Structure

“…Ferrite materials do not appear to be practical solutions for use in high frequency high gradient accelerators because of the extremely high loss factors and also because of possible interference of the high magnetic fields with the electron beam optics. We propose a new scheme that will allow control of the dielectric constant (and consequently the frequency spectrum) for dielectric waveguides by incorporating externally biased ferroelectric layers [23,[30][31][32][33]. The use of ferroelectrics for tuning purposes would appear to be a natural solution, except for the fact that most ferroelectrics are very lossy in the > 10 GHz frequency range.…”