RADIOACTIVITY

Degree course: 
Corso di Second cycle degree in PHYSICS
Academic year when starting the degree: 
2018/2019
Year: 
1
Academic year in which the course will be held: 
2018/2019
Course type: 
Compulsory subjects, characteristic of the class
Language: 
English
Credits: 
6
Period: 
First Semester
Standard lectures hours: 
48
Detail of lecture’s hours: 
Lesson (48 hours)
Requirements: 

It is required that the student have an introductory knowledge of nuclear physics, in particular on the structure of the atomic nucleus, the related models, and phenomena regarding the interaction of ionizing radiation with matter. However, since the formation of students in these areas is varied, depending on laboratories and courses taken, there will be an extensive summary on these subjects, in order to set uniform grounds for the development of the central part of the course.

Finally, it is necessary a good understanding of the English language, at the level required to read the slides that the teacher will use in the lectures (they will be often in English) and the recommended reference books.

Final Examination: 
Orale

The exam is oral, and typically consists of three main questions: one on the introductory part (radiation-matter interaction and detectors), one on radioactivity in general and one on applications or on specific issues. Clear-cut answers will not be requested, but in general the development of a subject, which may be complemented by additional questions that require short answers. At least one of the three main questions require an analytical work, in which the student will develop a series of mathematical steps to deduce a formula of particular relevance with pen and paper. Each main question will be given a score (up to 10); the final grade will be the sum of the three attributed sub-scores. If the note is 30, a question for Laude will be proposed to the student, in general to examine the student's ability to reason on topics that fall outside the program carried out (even though closely related to it), based on the information acquired.

Assessment: 
Voto Finale

The purpose of the course is to lead the student to acquire a general knowledge, albeit at an introductory level, about the phenomenon known as radioactivity. In addition to the basic physics and the most relevant models that describe it, the course will introduce elements relating to the numerous applications of this phenomenon, in the scientific, industrial and medical fields. The lectures will discuss the biological effects of radiation and will give the student the means to appreciate the impact of both natural and artificial radioactivity. (Descriptor of Dublin: Knowledge and Understanding.)

The course will aim also to develop the critical skills of the student, who will be provided with appropriate concepts and quantitative tools, in a subject where the emotional aspects are notoriously relevant. (Descriptor of Dublin: Making Judgments.)

Finally, the student will get the tools to deepen its knowledge on specific subjects, thanks to the basic knowledge acquired and to the indications provided by the course on where and how to obtain further information. (Descriptor of Dublin: Learning Skill.)

BASIC ELEMENTS OF RADIATION-MATTER INTERACTION

Interaction of heavy charged particles, fast electrons and gamma radiation with matter

Interaction of neutrons with matter

RADIATION DETECTORS

General features of a detector

Scintillators: operating principles, organic and inorganic scintillators, photodetectors

Semiconductor detectors: band structure of crystalline solids, semiconductor characteristics, doping, p-n junction, p-i-n junction, Ge and Si detectors

Criteria for the choice of a detector

INTRODUCTION TO RADIOACTIVITY

The discovery of radioactivity: a brief history

The periodic table and the table of nuclides, the concepts of isotope, isotone, isobar, radio-isotope

The radioactive decay: alpha decay, beta decay, electron capture and gamma rays

Natural radioactivity:

  • primordial radionuclides, natural chains of 238U, 235U, 232Th, concept of transient and secular equilibrium; examples of broken secular equilibrium <\li>
  • secondary cosmic radiation<\li>
  • cosmogenic radionuclides, in particular 3H, 7Be, 14C <\li>
    <\ul>
    The radioactivity in the life of every day: typical content of radionuclides in food, in the rocks, in the atmosphere

    RADIATION PROTECTION PRINCIPLES

    Ionizing radiation, LET, damage induced by ionizing radiation

    Definitions and units: absorbed dose, equivalent dose

    Biological effects of ionizing radiation

    The principles of radiation protection and introduction to environmental radiation protection

    APPLICATIONS OF RADIATION

    Industrial applications

    Medical applications of imaging techniques, therapeutic techniques

    Scientific applications: examples of the various radionuclide applications in various fields; radiometric dating and radiocarbon method

    RADON

    Discovery of radon (Rn), chemical characteristics of the Rn, isotopes of Rn

    Discovery of the dangerousness of Rn; particulate inhalation and Rn daughters, risk multiplicative factor for smokers

    Outdoor radon: sources, typical trends of concentrations, atmospheric profile

    Indoor radon: sources, mechanisms of accumulation, chimney effect, interventions for prevention and rehabilitation of housing

    Detection of Rn: Rn methodology measurements, active and passive methods, accumulation methods, the problem of Thoron, trace detectors, alpha-card, thermo-luminescence dosimeters, electret, ROAC, ionization chambers and electrometers, solid state detectors, scintillation cells

    DETECTORS AND HPGe GAMMA SPECTROMETRY

    Importance of gamma spectrometry

    The HPGe detectors

    Spectrum features: typical structure, photopeak, Compton distribution and backscattering peak, escape peaks, sum peaks

    Gamma spectrum analysis

    Techniques of low radioactivity measurements:

    • problem of environmental radioactivity, characteristics of a good shielding material <\li>
    • the Rn as a contaminant in low radioactivity measurements <\li>
    • intrinsic radioactivity detector <\li>
    • effects of cosmic radiation <\li>
      <\ul>

      NUCLEAR ENERGY

      Nuclear fission: model using the Weizsäcker formula for the nuclear mass, the fission barrier, spontaneous fission, induced fission, heat developed in the fission chain reaction, uranium enrichment

      The nuclear reactors

      Fundamental elements constituting all nuclear reactors, general operating principle of a nuclear reactor, PWR reactors, BWR reactors, HWR reactors, self-breeder reactors, graphite reactors, nuclear fuel cycle, Xenon poisoning

      Nuclear Safety and Energy: sources of danger in the use of nuclear energy, radiological hazards, reactor safety systems

      The Chernobyl and Fukushima events

The main part of the course will be based on slides, given the frequent need to show graphics, diagrams and test results and schemes of equipment and devices. A copy of the slides will be provided to students in electronic form before their projection.

Supporting texts, which have a function of consultation as the sldies are sufficient for the preparation of the final test, are the following:

- "Environmental radioactivity" - M.Eisenbud et T.Gesell - Academic Press
- "Practical application of radioactivity and nuclear radiations" - G. C. Lowental et P.L. Airey - Cambridge University Press - ISBN 0521 553059
- "Radioactivity, radionuclides, radiations" - J. Magill et J.Galy - Springer - ISBN 3-540-21116-0
- "Tecniques for nuclear and particle physics experiments" - W.R.Leo - Springer Verlag - ISBN 3-540-57280-5
- "Radiation and radioactivity on earth and beyond" - I.G. Draganic - CRC Press - ISBN 0-8493-8675-6

Convenzionale

Frontal lessons. The main part of the course will be based on slides, given the frequent need to show graphics, diagrams and test results and schemes of equipment and devices. A copy of the slides will be provided to students in electronic form before their projection.

Students can request an appointment to discuss course topics through the professor’s e-mail (andrea.giuliani@mib.infn.it), who will respond to students by one - two days offering a range of dates and times for the discussion, which will take place in the office of the professor.

Professors

GIULIANI ANDREA ERNESTO GUIDO