Gyrotron internal mode converter reflector shaping from measured field intensity

Gyrotron Internal Mode Converter Reflector Shaping from Measured Field Intensity

We present the formulation and experimental results of a new approach to designing internal mode converter reflectors for high-power gyrotrons. The method employs a numerical phase retrieval algorithm that reconstructs the field in the mode converter from intensity measurements, thus accounting for the true field structure in shaping the beam-forming reflectors. An outline for designing a four-...

Gyrotron mode converter mirror shaping based on phase retrieval from intensity measurements

Mode Excitation in a Gyrotron

Calculation of Radiation from a Helically Cut Waveguide for a Gyrotron Mode Converter in the Quasi-Optical Approximation

A gyrotron internal mode converter consists of a launcher that radiates the waveguide mode as a nearly Gaussian beam in free space, followed by a set of mirrors to focus and direct the radiation. We present a calculation of the radiation from the launcher based on a quasi-optical approach that includes diffraction. The results are in good agreement with a calculation using a numerical code base...

Cold testing of quasi-optical mode converters using a generator for non-rotating high-order gyrotron modes.

In this paper, we test the performance of a quasi-optical, internal-gyrotron mode converter. When cold testing mode converters, a rotating higher-order mode is commonly used. However, this requires a nontrivial design and precise alignment. We thus propose a new technique for testing gyrotron mode converters by using a simple, non-rotating, higher-order mode generator. We demonstrate the feasib...