Interaction and detection of nuclear radiation

A.Y. 2019/2020
6
Max ECTS
42
Overall hours
SSD
FIS/04
Language
Italian
Learning objectives
The course presents the basic principles of the interaction mechanisms of charge particles, gamma-rays and neutrons with matter. The general priciples and properties of radiation detectors will be discusses, with particular emphasis on gas detectors, scintillators and solid state detectors. Modern and future detection systems based on different kind of materials are discussed in connection with specific experiments at the frontiers of the nuclear physics research.
Expected learning outcomes
At the end of the course, the student will be informed about the mechanisms of interaction of radiation with matter. In particular, she/he will be able to estimate:
i) energy losses, according to Bethe-Block, range and straggling of particles in different materials:
ii) interaction probability for photoelectric, Compton and pair production interactions, for photons with keV-10 MeV energies;
iii) cross sections for neutron interactions, as a function of neutron energy, in particular for scattering and n capture.
The student will be able to discuss the working principles for:
i) gas detectors: ionization chambers, proportional counters, Geiger-Muller detectors;
ii) scintillator detectors: organic, inorganic, light guide, photomultiplier tubes:
iii) semiconductor detectors: pn junctions, high-purity detectors, in particular made of Si and Ge materials;
iv) neutron detectors.
The student will be able to propose optimal configurations for detection systems for specific, modern experiments in nuclear physics, which require advance instrumentation. For example:
i) arrays of large volume high-purity Ge detectors, composite or segmented;
ii) arrays of large volume scintillators, including phoswich type;
iii) instrumentation for electron conversion measurements;
iv) instrumentation for low-energy heavy-ion detection and arrays for fission fragments detection;
v) modular detection systems for fast neutron measurements.
Course syllabus and organization

Unique edition

Responsible
Lesson period
First semester
Course syllabus
The course aims at a detailed discussion of the mechanisms of the interaction of radiation with matter and related effects, and of the working principles of the main types of detectors. In particular, the following topics will be treated at length:
1) energy losses, according to Bethe-Block and related corrections, range, Bragg peak and straggling of ionizing particles in different materials;
2) interaction probability for photoelectric, Compton and pair production interactions, for photons with keV-10 MeV energies;
3) cross sections for neutron interactions, as a function of neutron energy, in particular for scattering and n capture: energy and angle distributions of scattered neutrons; neutron moderation and neutron detection.
4) gas detectors: ionization chambers, proportional counters, Geiger-Muller detectors;
5) scintillator detectors: organic, inorganic, light guide, photomultiplier tubes;
6) semiconductor detectors: pn junctions, high-purity detectors, in particular made of Si and Ge materials;
7) neutron detectors;
8) basics concepts for the treatment of the detector signals: amplitude (ballistic deficit, signal/noise, pile-up); preamplificaion, linear amplification; time measurements; true and random coincidences; pulse shape analysis;
applications to neutron-gamma discrimination;
9) use of ionizing radiation in medical application (adroterapy).
In the last part of the course, state-of-the-art detection setups will be discussed, focusing on selected examples mainly from low-energy nuclear physics. In particular, the following instrumentation will be considered:
i) arrays of large volume high-purity Ge detectors, composite (EUROBALL) or segmented (AGATA);
ii) arrays of large volume scintillators, including phoswich type (HECTOR and PARIS, MEDEA and TAPS);
iii) arrays for light charged particle detection (MICROBALL, ISIS, EUCLIDES, CHIMERA);
iv) instrumentation for electron conversion measurements (mini-orange spectrometers);
v) instrumentation for low-energy heavy-ion detection and arrays for fission fragments detection;
vi) modular detection systems for fast neutron measurements (NWALL).
Prerequisites for admission
Basic notions of nuclear and particle physics, as for example:
1. radioactive decays and decays laws;
2. nuclear fission;
3. basics of nuclear shell model;
4. collective nuclear excitations (rotation and vibration);
5. compound nucleus reactions and low-energy binary reactions;
6. cosmic rays;
7. electromagnetic showers.
Teaching methods
The course will be made of class lectures on each topic of the program, with the aid of projected slides, summarizing the lectures contents, and of plots/pictures illustrating in details the radiation interaction mechanisms and the instrumentation used for the detection of radiation, in general.
Bibliography
G.F. Knoll
Radiation Detection and Measurements
Wiley & Sons

W.R. Leo
Techniques for Nuclear and Particle Physics Experiments
Springer-Verlag
Assessement methods and criteria
The examination consists in an oral discussion about the topics i) interaction mechanisms of ionizing radiation (charged particles and gamma's) and neutrons and ii) working principles of gas detectors, scintillators and solid state detectors. A detailed discussion is also requested on a subject treated in the last part of the course, concerning the use of advanced instrumental techniques for the detection of radiation by state-of-the-art multi-detector arrays, focusing on selected experiments of low-energy nuclear physics, mainly. During the exam, the acquired competences and the capabilities for a critical discussion will be evaluated.
FIS/04 - NUCLEAR AND SUBNUCLEAR PHYSICS - University credits: 6
Lessons: 42 hours
Professor: Leoni Silvia
Professor(s)