Giovanni Cerretani
I attended the Liceo Scientifico in Siena, graduating in 2008 with 98/100. Then I got my bachelor's degree in Physics and Advanced Technologies at the University of Siena in December 2011. My thesis consisted in the characterization of the electronics of the level-zero trigger boardfor the “Cherenkov Telescope Array”'s detectors, under the supervision of prof. Riccardo Paoletti (University of Siena – INFN of Pisa).
At that point, being mostly interested in the experimental part of the science, I moved to Pisa, where I attended the courses of Particle Physics of the master's degree, in order to graduate in May 2014. My thesis has been developed at the gravitational wave observatory Advanced Virgo within the INFN Pisa group, under the supervision of dott. Diego Passuello and ing. Alberto Gennai. There I have studied the horizontal accelerometers, feedback-controlled sensors used in the seismic isolator inertial control to measure the seismic noise. Using the computing power of the new electronics, I have designed a new digital control system for the accelerometers, exploiting the properties of a critically damped harmonic oscillator. This system allows to improve by about one order of magnitude the sensitivity of these sensors, with respect to the system used in Virgo. I have also designed a system to read the output of the Linear Variable Differential Transformers (LVDT), a kind of displacement sensor, using a FPGA. It consists of a Direct Digital Synthesizer (DDS) that is used both to drive the primary coil of the LVDT with a sine wave at 50 kHz, and then to demodulate the signal induced on the secondary coils, whose amplitude is modulated by a signal proportional to displacement. An algorithm, based on a Phase-Locked Loop (PLL), allows the detection of the phase shift of the signal induced on the secondary coils, and tunes the system in order to maximize the signal-to-noise ratio of the measurement of displacement.
PhD Theses
2018
Software of Advanced Virgo Suspension Control System PhD Thesis
29.01.2018, (Relatore: Prof. D.Passuello).
Presentations
2016
Software for the Suspension Control System of Advanced Virgo Presentation
28.09.2016.
2015
Quantization noise: theory and techniques Presentation
25.09.2015.