| Paper | Title | Page |
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| TH5RFP001 | Development of Metamaterials for Cherenkov Radiation Based Particle Detectors | 3432 |
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Funding: DOE Metamaterials (MTMs) are periodic artificially constructed electromagnetic structures. The periodicity of the MTM is much smaller than the wavelength of the radiation being transported. With this condition satisfied, MTMs can be assigned an effective permittivity and permeability. Areas of possible application of MTMs in accelerator science are Cherenkov detectors and wakefield devices. MTMs can be designed to be anisotropic and dispersive. The combination of engineered anisotropy and dispersion can produce a Cherenkov radiation spectrum with a different dependence on particle energy than conventional materials. This can be a basis for novel non-invasive beam energy measurements. We report on progress in the development of these media for a proof-of-principle demonstration of a metamaterial-based beam diagnostic. |
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| TH6REP037 | Radiation of a Charge Crossing a Left-Handed Medium Boundary and Prospects for its Application to Beam Diagnostics | 4030 |
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Funding: Physical Faculty of St.Petersburg State University (14.10.08); SBIR DOE (DE-FG02-08ER85031) Radiation of a charge crossing the boundary between vacuum and left-handed medium is analyzed. The medium is characterized by permittivity and permeability with frequency dispersion of “plasmatic” type. Such properties can be realized in some modern metamaterials with a relatively simple structure. Both the case of unbounded medium and the case of circular waveguide are considered. Analytical expressions for field components are obtained and algorithm of their computation is developed. The main attention is given to the analysis of radiation in vacuum region. In particular, it is shown that two types of radiation can be generated in this region. One of them is an ordinary transition radiation having relatively large magnitude. Another type of radiation can be named the “Cherenkov-transition” radiation. Conditions of generating this type of radiation are obtained. This effect and some another properties of radiation can be used for diagnostics of beams. For example, the detector with two energy thresholds can be designed. |
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| TH6REP038 | High Precision Beam Energy Measurement with Cherenkov Radiation in an Anisotropic Dispersive Metamaterial Loaded Waveguide | 4033 |
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Funding: SBIR DOE (DE-FG02-08ER85031); Russian Foundation for Basic Research (06-02-16442-a); Physical Faculty of St.Petersburg State University (Russia) (14.10.08) We consider microwave Cherenkov radiation in a waveguide containing an engineered medium, and show that the properties of the radiation can be used to determine the energy of charged particle beams. These properties can form the basis of a new technique for bunch diagnostics in accelerators. We propose to use a material characterized by a diagonal permittivity tensor with components depending on frequency as in the case of a plasma but with the constant terms not equal to unity. These properties can be realized in a metamaterial with a relatively simple structure. In contrast to previous work in the present paper a vacuum channel in the waveguide is taken into account. The particle energy can be determined by measurement of mode frequencies. It is shown that a strong dependence of mode frequencies on particle energy for some predetermined narrow range can be obtained by appropriate choice of the metamaterial parameters and radius of the channel. It is also possible to obtain energy measurements over a wider range at the cost of a weaker frequency dependence. *A.V.Tyukhtin, S.P.Antipov, A.Kanareykin, P.Schoessow, PAC07, p.4156. |