87993 - HEALTH PHYSICS

Learning outcomes

At the end of the course the student will acquire the basic knowledge on the most important and interesting topics in the field of Health Physics. In particular the student will be able to: - understand the different types of interactions of ionizing radiations with matter and their biological effects; - understand the problems related to the radioprotection of workers and population; - distinguish among the most important kinds of radiation detectors; - use an acquisition chain for alpha or gamma spectrometry.

Course contents

The course is divided into two learning modules.

 

Contents of Module 1 (5 CFU):

- Ionizing radiation: interactions of high-energy photons with matter: photoelectric effect, Rayleigh scattering, Compton scattering, pair production, photonuclear interactions. Interactions of charged particles with matter. Bethe-Bloch formula. Bragg peak and particle range. Interactions of neutrons with matter. LET (Linear Energy Transfer).

- Biological effects of ionizing radiation: mechanisms of radiation damage: direct and indirect action of ionizing radiation. The free radicals. Effects of radiation on cells: DNA damage and survival curves for viruses, bacteria and mammalian cells. Radiosensitivity of the cell in relation to the cell cycle phase. Relative Biological Effectiveness (RBE). Effects of radiation on humans: deterministic and stochastic damage. Epidemiological studies.

- Dosimetry of ionizing radiation: main dosimetric quantities: exposure, absorbed dose, equivalent dose and effective dose. Weight factors for different types of ionizing radiation and for the different tissues of the human body.

- Basics of radiation protection: principles of radiation protection. Concept of risk index. Classification of work areas and occupationally exposed workers. Dose limits.

- Radiation detectors: gas detectors, scintillation detectors and solide state detectors. TLD dosimeters. Electronics for signal acquisition and processing. Alpha and gamma spectra analysis.

- Introduction to alpha spectrometry: Calibration of a Multi-Channel Analyzer. Energy loss produced by an absorbing material. Laboratory practice with a silicon surface barrier detector for alpha spectrometry.

- Introduction to gamma spectrometry: Gamma ray sources. Gamma spectra analysis. Laboratory practice with a CdTe detector.

- Introduction to X-ray imaging techniques: X-ray tubes and detectors for digital radiography. Characteristic parameters of an X-ray imaging detector. Outline of X-ray Computed Tomography and its applications in the medical, industrial and Cultural Heritage fields. Laboratory practice with an acquisition system for digital radiography and Computed Tomography.

The laboratory activities will be performed at the end of the learning module, after the lectures in the classroom.

 

Contents of Module 2 (1 CFU):

- Numerical dosimetry: the simulations of the radiation interactions with matter: introduction to Monte Carlo simulation; numerical simulation and anthropomorphic models for dose evaluation; anthropomorphic models from CT scan development; ICRP (International Commission on Radiological Protection) voxel reference models and anthropomorphic models.

- Radiation fields: some examples of radiation fields; practical aspects of radiation protection and dosimetry; radiation shielding examples.

Readings/Bibliography

• J.T. Bushberg, J.A. Seibert, E-M. Leidholdt, J.M. Boone: "The Essential Physics of Medical Imaging", Wolters Kluwer-Lippincott Williams & Wilkins, 2012.

• H.E. Martz, C.M. Logan, D.J. Schneberk, P.J. Shull: "X-ray imaging: Fundamentals, Industrial Techniques and Applications", CRC Press, 2017.

• C.A. Kelsey, P.H. Heintz, G.D. Chambers, D. J. Sandoval, N.L. Adolphi, K.S. Paffett: “Radiation Biology of Medical Imaging”, John Wiley & Sons, 2014. 

• J.E. Coggle: “Biological effects of radiation”, Taylor & Francio Ltd, London.

• H.E. Johns and J.R. Cunningham: “The Physics of Radiology”, Charles C. Thomas Publisher.

• G.F. Knoll: "Radiation detection and measurement", John Wiley & Sons, Inc.

• R.F. Laitano: "Fondamenti di dosimetria delle radiazioni ionizzanti", ENEA.

• M. Pelliccioni: “Fondamenti fisici della radioprotezione”, Pitagora Editrice, Bologna.

 

The slides will be available after each lecture on the following website: https://iol.unibo.it/course/view.php?id=23499

 

Further readings:

• R. L. Morin: “Monte Carlo Simulation in the Radiological Science”, CRC-Press.

• X.G. Xu and K.F. Eckerman: “Handbook of anatomical models for radiation dosimetry”, CRC-Press.

• J.C. Russ: “The Image Processing Handbook”, CRC-Press.

• D. Salomon:“Curves and Surfaces for Computer Graphic”, Springer.

Teaching methods

Classroom lectures, followed by laboratory activities during which the students will be divided into small groups.

After each laboratory activity the students are required to write a written report that can be prepared either individually or in group and whose evaluation will contribute to the final grade.

Practical activities also have the purpose of making the students acquire processing and synthesis skills, as well as teamwork skills.

Assessment methods

The final exam aims to assess the achievement of the main learning objectives of the course:

■ understanding of mechanisms of ionizing radiation-matter interaction and the resulting biological effects in living organisms;
■ understanding of the issues related to radiological protection of workers and the population in activities involving the use of ionizing radiation;
■ knowledge of the main types of radiation detectors;
■ laboratory use of an acquisition chain for alpha spectrometry and gamma of a system of X-ray imaging

The final exam consists of an oral interview on the topics covered in classroom lessons and on laboratory activities,  which aims to assess the degree of learning of the contents, the critical and methodological skills and the use of a specific language. The acquiring of an organic view of the topics discussed in class, along with their critical consideration, the ability to expose the concepts with mastery of the subject and adequate language will be recognized with very good or excellent grades. A mostly mnemonic knowledge of the subjects and a limited ability of synthesis and analysis will lead to grades from discreet to sufficient. Important knowledge gaps and inappropriate language will result in a negative evaluation.

Teaching tools

Video-projector and PC.

Dedicated student laboratories for alpha and gamma spectrometry.

Laboratory for X-ray imaging.

The teaching material is available on the website: https://iol.unibo.it/course/view.php?id=23499

Office hours

See the website of Maria Pia Morigi

See the website of Paolo Ferrari