Nuclear physics laboratory

A.Y. 2021/2022
Overall hours
FIS/01 FIS/04
Learning objectives
This course aims to familiarize the students with the experimental aspect of some concepts that have been introduced in the course of Nuclear and Particle Physics: mean lifetime, cross section and passage of radiation through the matter. The students will learn the principles and techniques of nuclear radiation detection, including cosmic ray detection, and familiarize with electronic amplification and signal processing, and with data acquisition techniques. They will understand the importance of planning a simple, but non-trivial physics experiment, taking into account systematic and statistical uncertainties. All techniques acquired in previous labs, including programming skills, will be used in this lab, but a different context. Finally, students will learn how to write a scientific report and how to prepare a scientific presentation. The knowledge and skills provided by this course can be used in fundamental research and in other areas of applied physics
Expected learning outcomes
By the end of the course the students will be able to
1. Design and plan a measurement involving nuclear or natural radiation (cosmic rays)
2. Match the type of detector to the intended measurement process
3. Tune parameters of a nuclear electronic equipment
4. Calibrate a radiation detector
5. Measure and subtract noise and natural background
6. Operate a data acquisition system, collecting thousands of data points
7. Analyse the experimental data, to produce graphics showing both statistical and systematic errors, and fits to theoretical models
8. Interpret the experimental outcome, make a critical assessment and draw valid conclusions by comparing the measured values with previous measurements
9. Prepare a detailed written scientific report, both individually and within a team
Course syllabus and organization

Single session

Lesson period
Second semester
In case of limited access to the class, lectures will be delivered on-line with synchronous participation of the students. The hand written lecture notes will be uploaded to the Ariel site immediately after the lectures. In case of total lack of access to the laboratories we shall use low cost particle detectors, like Geiger counters. Students will borrow from the lab the instruments to take data actively from their home. Other measurements will be performed remotely by the lecturer, with active and synchronous participation of the students, who will then analyse the data and will write a laboratory report.
Course syllabus
Introductory lectures
Review of radioactivity and interaction of radiation with matter;
Radiation detectors based on drift of electric charges and scintillating detectors. Ionization and drift in gas, liquid and solid-state semiconductor detectors.
Radiation shielding and detection efficiency: exercises
Review of nuclear electronics instrumentation: preamplifiers, amplifiers, coincidence unit, scalers, delay lines and cables, ADC's TDC's.
The photomultiplier and solid-state photon detecting devices (SiPM)
Review of statistics and error propagation; energy and time resolution
Cosmic rays; cross sections.
Working with radioactive sources: safety and elements of radio protection.
Lectures will be delivered in Italian and English technical translations will be mentioned. If asked by the students, lectures can be delivered in English.

Laboratory activity
Common to all experiments
i. Optimizing the parameters of an electronic amplification chain and detector calibration;
ii. Analysis of background
iii. Data acquisition and data analysis
Radiation detection techniques (one experiment out of the following)
a) Spectrum of a beta emitting nuclide obtained with a Si detector
b) Spectra of alpha emitting nuclides with a Silicon detector
c) Spectra of gamma emitting nuclides obtained with an inorganic scintillator.
d) Radioactivity measurement: K spectrum
e) Energy and time resolution of plastic scintillators
f) I-V and C-V curves of semiconductor detectors: detection efficiency
Nuclear and particle physics experiments (one out of the following)
a) Measurement of the Compton differential cross section
b) Measurement of the muon lifetime and of the cosmic muon flux with precise time stamp
c) Measurement of the Rutherford cross section
a) Measurement of energy loss of alpha particles in air
b) Measurement of the gamma attenuation factor for various material at various energies
c) Measurement of beta spectrum parameters: limits to the neutrino mass

All experiments use computer-based data acquisition, and students are required to prepare and run simple programs to analyse the data, using root.
Prerequisites for admission
The students are expected to be familiar with statistical treatment of experimental errors. They should have attended a course equivalent to "introduction to nuclear and subnuclear physics", and have understood and retained the main concepts of radioactive decay, cross section, passage of radiation through the matter. They should also have attended a course equivalent to "Numerical analysis of experimental data" and they should be able to use the "root" environment to write or modify simple data analysis programs to produce plots and histograms.
Teaching methods
Introductory lectures and case study exercises will introduce the radiation detection measurements. The second part will take place in the lab, where students will first be introduced to the instruments and will be shown how to design and plan an experiment. They will then perform two measurements among those proposed, and will write a lab report on each of them, in Italian or English. One group of students will perform a measurement in collaboration and communication with students of Praha and Copenhagen, who will use a very similar experimental setup, exchanging data and checking each other results. This activity occurs within the 4EU+ collaboration.
Teaching Resources
Techniques for Nuclear and Particle Physics Experiments, W. R. Leo
Radiation Detection and Instrumentation, G.F. Knoll
Physics and Engineering of Radiation Detection, S. N. Ahmed
Introduction to Nuclear and Particle Physics, S. D'Auria
Lecture notes and handouts, in Italian and English.
Assessment methods and Criteria
The assessment for this course is based on four elements: the student's active participation to the team work during lab activity; the two laboratory reports on the measurements that have been performed; a final presentation on one of the measurements performed; an oral exam addressing both the lab reports and the knowledge of functioning principles of particle detectors. The basic principles of radioprotection is also part of the examinable topics.
FIS/01 - EXPERIMENTAL PHYSICS - University credits: 0
FIS/04 - NUCLEAR AND SUBNUCLEAR PHYSICS - University credits: 0
Laboratories: 54 hours
Lessons: 12 hours
Professor: D'Auria Saverio
Educational website(s)