University of California, Berkeley
Microwave Measurement and Beam Instrumentation Lab
Ralph Pasquinelli and Dave McGinnis, Fermilab
Purpose and Audience
This laboratory course is designed for students with a theoretical accelerator physics background to gain insight into the workings and capabilities of modern instrumentation. Students will spend most of their time on actual measurements.
Prerequisites
Undergraduate Electromagnetism and Accelerator Fundamentals.
Objectives
Provide the student with hands-on measurements of accelerator related hardware and signals utilizing state of the art measurement equipment.
Instructional Method
This course includes a series of 8 lectures during morning sessions, supplemented experimental sessions to emphasize the implementation of theoretical concepts. Theses hand-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.
(8) Use of a vector signal analyzer for measuring beam signals.
Course Content
(1) Microwave Measurements in the time and frequency domains, basics of spectrum analyzers, vector signal 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 of matching devices; and
(8) RF cavity measurements, cavity basics, bead pull, coupling, cavity bandwidth.
Reading Requirements
“Microwave Theory and Applications” by Stephen F. Adam will be used as reference material. The course will follow our notes which will be available on-line.
Credit Requirements
Students will be evaluated based on performance in the laboratory. Both instructors will be actively involved with each of the students during the course of each day and each experiment. The experiments have definitive responses and the instructors will monitor the results. If the student has the wrong answer, he(she) needs to repeat the experiment to see where a mistake was made. The instructors check with each student to see that they have made the measurements correctly.