510303 - LABORATORY OF NUCLEAR AND SUBNUCLEAR PHYSICS I

courses

ID:

510303

Duration (hours):

60

CFU:

SSD:

FISICA NUCLEARE E SUBNUCLEARE

Year:

2025

Date/time interval

Secondo Semestre (02/03/2026 - 05/06/2026)

Course Objectives

The course aims to train students in the use of some measurement techniques commonly used in experimental nuclear and subnuclear physics through the use of electronic modules for the processing of signals from detectors. In this regard, both organic and inorganic scintillation detectors, solid state detectors and possibly gas detectors will be used. At first, the signal of the actual detectors will be simulated by means of pulse generators in order to calibrate and test the acquisition chains for the various measurements. Subsequently, once the operation of the acquisition modules is understood, the detectors will be introduced to carry out the measurements.

Course Prerequisites

Notions of electromagnetism, quantum mechanics and nuclear and subnuclear physics

Teaching Methods

Lectures are provided together with laboratory sessions dedicated to the preparation of nuclear and subnuclear physics experiments through which students perform measurements. The results are then analyzed and discussed.

Assessment Methods

The exam can be oral or will consist in the execution of an experimental measurement with the instrumentation used during the course. Although it is not an English-friendly course, the exam can be taken in English at the request of the student.

Texts

G.F. Knoll, Radiation detection and measurements; Wiley, (New York 2003). W.R.Leo , Techniques for nuclear and Particle Physics experiments (Springer, 1994). W.Blum, L.Rolandi, Particle detection with drift chambers (Springer, 1994). Lecture notes by the teacher.

Operational definition of cross section of a process, linear attenuation coefficient, mean free path in gases, ionization statistics in gases. Generation through Monte Carlo. Generation of random variables according to notable distributions. Outline of experimental aspects of radiation protection: calculation of the absorbed dose due to radiation from point sources. Experimental aspects in measuring the efficiency of a detector. Justification of the use of detectors in coincidence. Loss of energy: Bethe – Bloch formula and simulation of the energy lost by a charged particle. Charge development in a gas detector: first and second Townsend coefficient; attachment and effective Townsend coefficient. Signal induced on the electrodes of a detector: particular cases of Ramo's theorem. Application to gas detectors with cylindrical and flat geometry. Time resolution of a detector; definition of Jitter and temporal Time Walk of a detector signal. Some measures will be:Transmission lines and impedance mismatch. Line impedance measurement. Measurement of spurious coincidences between two generators as a function of the temporal formation window. Discrimination modules, logic, counters, Multichannel Analyzer, Time to Amplitude Converter. Coincidence techniques for measuring the absolute activity of a radioactive source. Measurement of linear attenuation coefficient by range in different materials, build-up measurement. Measurement of the efficiency of a scintillator as a function of voltage. Characteristic curve of a photomultiplier, coincidence counts. Working point of an organic scintillator. Measurement of the differential pulse height spectrum of an inorganic NaI (Tl) scintillator subjected to gamma radiation. Energy calibration of a multichannel and energy spectra with 22Na and 137Cs sources. For all these measures the experimental aspects and the various problems will be discussed.