PHYSICS LABORATORY III

Provide a basic knowledge of experimental techniques concerning the interaction of radiation with matter, particle detectors, signal processing, electronics as well as statistical methods for simulation and data analysis.

With reference to "Dublin descriptors", this Course contributes to provide the following skillness:

• Ability in induction and deduction methods
• Capability to learn and evaluate experimental results from physics experiments.
• Capability to setup and define a problem by using quantitative relations (algebraic, differential, integral) between phyisical variables and to solve it by means of analystical or numerical algorithms.
• Capability to carry out statistical analyses of results.
• Capability to perform analysis sessions of experimental data from modern physics experiments.

Capability to apply the knowledge in order to:

• Describe physical phenomena by a correct and quantitative application of scientific methodologies.
• Evaluate the performance of experiments in nuclear physics and carry out the analysis of experimental data.
• Perform numerical calculations and simulation procedures.

Autonomy of judgment:

• Reasoning skills.
• Capability to find the most appropriate methods for a critical evaluation and interpretation of experimental data.
• Capability to understand the prediction of a model or theory.
• Capability to evaluate the accuracy and importance of existing measurements.
• Capability to evaluate the goodness and limits in the comparison between experimental data and theoretical predictions.

Communication skills:

• Capability to appropriately communicate scientific topics and problems, discussing the motivations and main results.
• Capability to describe in a written report a scientific topic or problem, discussing the motivations and main results.

1) Lectures

2) Exercises during hall lectures

3) Laboratory demonstrations

4) Experiments in the lab by the students

5) Data analysis sessions and simulation exercises

Should the circumstances require online or blended teaching, appropriate modifications to what is hereby stated may be introduced, in order to achieve the main objectives of the course.

Content of the course:

Parte I

1. Techniques and laboratory instrumentation

Sensors for the measurement of physical quantities - Analog and digital sensors - Data acquisition from sensors - Digital multimetere- Analog and digital oscilloscopes - Vacuum techniques - Elements for vacumm production and measurement - Measurement of radiations from Infrared to ultraviolet - Optical fibers - Spectrophotometers - Radioactive sources

2. Radiation Detectors

Interaction of charged particle with matter - Bethe-Block relation - Range - Straggling - Energy loss of electrons and positrons - Photon interaction - Photoelectric effect - Compton Effect - Pair production - Electromagnetic showers - Particle detectors - Measure of energy, momentum, position, mass and charge of particles - General properties of a detector: sensitivity, resolution, efficiency, dead time - Gas detectors - Ionization chambers - Geiger counters - Solid state detectors - Strip, drift and pixel detectors - Radiation damage - Scintillation detectors - Light yield - Photomultipliers - Light guides and WLS fibers - APD and SiPM.

3. Elements of Electronics

Pulse signals from detectors - Analog and digital signals - Propagation of signals - Coaxial cables - SIgnal Generators- Power supply - Electronics for Nuclear Physics - The NIM standard - Linear electronics: preamplifier, amplifier, shapers - Basic knowledge of logic electronics: OR, AND, NOT circuits - Analog-to-digital converters (ADC and QDC) - Discriminators - Coincidence circuits - Counters - Trigger systems - Data acquisition - Digital pulse processing

4. Data analysis and simulation techniques

Knowledge of elementary statistics - Central values and dispersion indexes - Experimental distributions - Gauss and Poisson distributions - Experimental errors - SIgnificance test - Data analysis techniques in nuclear physics experiments - Spectra analysis - Background subtraction - Non linear fits . Multiparametric analysis - The ROOT software - SImulation of physical processed - Monte Carlo methods the GEANT package for detector simulation

Part II: Laboratory experiments

1) Characterization of time dependent light sources by sensors

2) Photoelectric effect and the measurement of the Planck constant

3) Study of discrete and continuous light spectra with a digital spectrophotometer

4) Detection of electrons with a Geiger counter and study of the absorption coefficient

5) Study of the light absorption at different frequencies

6) Gamma spectrometry and absorption coefficient with scintillators

7) Alpha spectrometry and study of energy loss with silicon detectors

8) Measurement of the energy spectrum of a beta source

For the items concerning the interaction of particle and radiation with matter, particle detectors and electronics see one of the following textbooks:

1) William R. Leo, Techniques for Nuclear and Particle Physics Experiments, Springer-Verlag

2) Glenn F. Knoll, Radiation Detection and Measurement, John Wiley and Sons

3) Claude Leroy and Pier-Giorgio Rancoita, Principles of Radiation Interaction in Matter and Detection, World Scientific

4) C.Grupen, B.Schwartz, Particle Detectors, Cambridge

Additional references (textbooks, specific papers and reference manuals) will be discussed during the lectures and made available on the Web site