U.S. Particle Accelerator School
U.S. Particle Accelerator School
America's National School of Accelerator Science and Technology

Microwave Measurements and Beam Instrumentation Laboratory

Sponsor:

Northern Illinois University

Course Name:

Microwave Measurements and Beam Instrumentation Laboratory

Instructors:

Gang Huang, Tianhuan Luo, Shree Subhasish Basak, Shreeharshini Dharanesh Murthy, Yilun Xu, Lawrence Doolittle, Lawrence Berkeley National Laboratory and Wencan Xu, Brookhaven National Laboratory

Purpose and Audience
Modern accelerators rely on beam manipulations using electromagnetic fields at microwave RF frequencies. This laboratory course introduces the student to RF and microwave technology and laboratory methods employed for its characterization. The course consists primarily of laboratory exercises.  Short lectures introduce essential features of topics covered in the laboratory exercises.

Prerequisites
Undergraduate level Electromagnetism and the knowledge of basic accelerator science and technology at the level of USPAS course Fundamentals of Accelerator Physics and Technology with Simulations and Measurements Lab or USPAS graduate Accelerator Physics is required.

It is the responsibility of the student to ensure that they meet the course prerequisites or have equivalent experience.

Objectives
Provide the student with practical experience in measurements of RF and microwave accelerator hardware and signals using modern equipment.

Instructional Method
This course includes a series of lectures introducing fundamental concepts of microwave theory and the lab topics during morning sessions, and extensive afternoon lab sessions to demonstrate theoretical concepts. These hand-on labs include:

  1. Spectrum Analyzer: Measurement of signals on a spectrum analyzer to understand resolution bandwidth, video bandwidth, dynamic range, noise, etc.
  2. Vector Network Analyzer: Use of a VNA to measure RF properties of various RF components, including cables, Tee-junctions, filters, kickers, cavities, etc.
  3. Time Domain Reflectometry (TDR): Measure characteristics of various connector families, transmission lines, and complex loads.
  4. Beam Signals: Utilize an arbitrary function generator to simulate beam signals from the accelerator; Amplitude Modulation (AM) for betatron signals, Frequency Modulation (FM) for synchrotron signals.
  5. Beam Pickups and Kickers: Measure and understand the performance of a stripline used as either a beam pickup or kicker.
  6. Beam Impedance: Use the wire method to measure the beam impedance of an accelerator element.
  7. RF Cavities: Measure mode spectrums of a cavity, the cavity coupling, loaded and unloaded Q, the electric field distribution and R/Q of a cavity by the bead pull method.
  8. Linac Structures: Measure mode spectrums of coupled cavities, loaded and unloaded Q; identify and understand the coupled modes and phase advance between cavities.

Instructors will be actively involved with each of the students during the course of each day and each experiment. The students will be evaluated by one-on-one discussions about the experiments. Students will submit written lab reports and solutions to the homework assignments. Instructors will be available for guidance during evening homework sessions.

Course Content
Topics covered include:
  1. Microwave Measurements in the time and frequency domains, basics of spectrum analyzers, vector network analyzers, and time domain reflectometers.
  2. Transmission lines, complex impedance, reflection coefficients.
  3. Beam signals for circular accelerators; beam spectrums, power spectral density, betatron and synchrotron signals.
  4. Stripline pickups and kickers, including beam impedance measurements.
  5. RF cavity and linac structure measurements; cavity and coupled cavity basics, bead pull, coupling, and cavity bandwidth.


Reading Requirements
(to be provided by the USPAS) Microwave Engineering by David Pozar (fourth edition), John Wiley and Sons (2011).

Credit Requirements
Students will be evaluated based on laboratory reports (50% course grade), final presentation (20% course grade) and lab performance in discussions with instructors (30% course grade). 

USPAS Computer Requirements
There will be no Computer Lab and all participants are required to bring their own portable computer to access online course notes and computer resources. This can be a laptop or a tablet with a sufficiently large screen and keyboard. Windows, Mac, and Linux-based systems that are wifi capable and have a standard web browser and mouse are all acceptable. You should have privileges for software installs. If you are unable to bring a computer, please contact uspas@fnal.gov ASAP to request a laptop loan. Very limited IT support and spare loaner laptops will be available during the session.

NIU course number: PHYS 790D Special Topics in Physics - Beam Physics
Indiana University course number: Physics 571, Introduction to Accelerator Physics
MIT course number:  8.790, Accelerator Physics

USPAS Code of Conduct