• control system
• detuning
• Fermilab
• fpga
• lorentz force
• microphonics

The purpose of this thesis is to develop a control system for superconducting
cavities, which are the key elements of linear accelerators. In this case the
cavities are resonant filters fed with an electromagnetic field at 1.3 GHz. The
system works on the compensation of mechanical distortions with fast tuners.
Mechanical distortions modify the resonance frequency of the cavities causing
significant inefficiency in the acceleration process. Typical high energy linear
accelerators consist of thousands of cavities so a compensation system is
required in order to avoid huge power losses.
The first part of the thesis is the work I have done to understand the detuning
sources, and the kind of controls needed for each source (described in chapter
1). The second part is a survey of electronic boards that can achieve the goal
with the lowest cost and high flexibility (chapter 2). The next step of my work
consists of the study of the processing needed for each kind of detuning sources
(chapter 3), making it easy to develop, to modify, to test and to improve using
LabView FPGA and MATHSCRIPT on an existing National Instrument system.
Another important enhancement that is achieved is to speed up the transfer of
data to the FPGA through the FIFO block of LabView by modifying the codes
written for hardware implementations using VHDL, C++, and LabView
programming
Finally tests on a real cavity show a good detuning compensation.