U.S. Particle Accelerator School

Microwave Measurement and Beam Physics Laboratory course

Sponsoring University:



Microwave Measurement and Beam Physics Laboratory


David McGinnis and Ralph Pasquinelli, Fermilab

The course consists of lectures and hands-on laboratories. Topics of lectures include (1) Microwave measurements in the time and frequency domains, basics of spectrum analyzers and time domain reflectometers; (2) Transmission lines, complex impedance, reflection coefficients; (3) Microwave measurements with a vector network analyzer, basics of vector network analyzers; (4) Microwave components and devices, splitters, circulators, directional couplers, filters, etc.; (5) Beam signals for circular accelerators, beam spectrums, power spectral density, betatron and synchrotron signals; (6) Signals, noise, and dynamic range, basic noise performance of devices and systems; (7) Impedance matching, basic principles of matching devices; and (8) RF cavity measurements, cavity basics, bead pull, coupling, cavity bandwidth. Hands-on labs include (1) Spectrum analyzer: for measurement of simple signals on a spectrum analyzer to understand resolution bandwidth, video bandwidth, dynamic range, noise, etc; (2) TDR: measuring characteristics of various connector families, transmission lines, complex loads; (3) Components: measuring the s-parameters of a variety of components; (4) Beam signals: utilize an arbitrary function generator to simulate beam signals from the accelerator, AM for betatron signals, FM for synchrotron signals; (5) Noise: consists of measuring the noise performance of a microwave amplifier. The amplifier will then be part of a "system" and noise performance of the system will be compared to individual noise performance of the components; (6) Matching: design and build a simple single stub transmission line matching circuit; and (7) RF Cavities: measure mode spectrums of a cavity, the cavity coupling, loaded and unloaded Q, the electric field profile and R/Q of a cavity by the bead pull method. Prerequisites: a course on electromagnetism.