NFYK13018U CANCELLED - Topics in Medical Physics
We aim at giving a thorough theoretical introduction to sources
of radiation and the interaction of ionizing radiation with matter.
The course also contains two experimental exercises which introduce
the students to detection of radiation and measurement of dose. The
students will understand the sources of radiation, the different
energy scales of the radiation and the matter which it traverses,
and the ionization processes, which eventually may cause damage to
biological systems. Through studies and discussions of recent
scientific papers and reports the students will acquire glimpses of
modern applications of radiation and the intricacies of estimating
the risks of small doses of radiation.
- Sources of radiation and decay laws.
- Classical and quantal scattering of charged particles, energy loss, stopping power and straggling of radiation in matter, the Bethe formula and the Bragg peak.
- Photo-absorption, Compton scattering and pair production for gamma rays in matter.
- Interaction of neutrons with matter.
- Dosimetry - dose from external and internal sources, effective half life, Medical Internal Radiation Dose method (MIRD).
- Biological effects of dose, survival curves of prepared cells. Effects of radiation on whole organisms. Acute effects of large doses - stochastic long time effects of small or medium doses.
- Application of radiation for diagnostics and tumor treatment. Radiation protection.
After completing the course, the student should to receive the top grade be able to:
- Describe the sources of natural radiation and radiation generated by technical means, that is radioactive nuclei, cosmic radiation, X-ray machines, particle accelerators and neutron sources.
- Explain the basic exponential decay law, the basic algebra of decay chains, and Poisson statistics for counting of radiation.
- Describe the interaction of charged particles with matter, and the ionization processes and their dependence with the velocity of the radiation, especially as evidenced by the Bragg peak
- Differentiate between the various interaction processes of gamma rays with matter, photo-absorption, Compton scattering and pair production, and qualitatively discuss their relative importance for light versus heavy elements, and for small versus large gamma ray energy.
- Describe the interaction of neutrons with matter, scattering, thermalization, absorption and subsequent decay.
- Explain the basic definitions and requirements for measurements of exposure and dose.
- Understand the basis for thermoluminescent dosimetry, carry out and describe dosimetry measurements in various geometries (experimental exercise).
- Describe the scintillation detection equipment of gamma rays, and differentiate between the various peaks and bumps of gamma spectra in relation to photo-absorption and Compton scattering. (experimental exercise)
- Describe the basic biological effects of dose as evidenced by cell survival curves.
- Explain the connection between linear energy transfer and biological damage expressed through biological weight factors and effective dose.
- Explain the various damages to DNA by ionizing radiation, such as single and double DNA strand breaks, which may lead to lethal damages such as ring formation.
- Describe the biological effects of radiation on whole organisms, that is acute effects of large doses and stochastic long time effects of small or medium or doses.
- Calculate and evaluate the external dose and exposure from a given source, including buildup factors in shielding.
- Explain the principles of evaluation of dose from internally deposited radiation, including the estimation of effective half life, and the scattering between different organs, as tabulated in the "Medical Internal Radiation Dose method" (MIRD).
- Calculate and evaluate the internal dose to various organs based on tables of lifetimes, biological lifetime and relative absorbed dose from MIRD tables.
- Describe and explain the contributions from various sources of radiation to the dose received by the general public.
- Describe qualitatively the application of radiation for diagnostics and tumor treatment, CT scans, SPECT and PET.
- Demonstrate - through the discussion of a scientific paper - application of the concepts and terms introduced in the course.
The student obtains an understanding of the physical background
for the interaction of ionising radiation with matter, especially
biological matter and a knowledge of the concept of dose so as to
evaluate the dose in actual cases. In addition knowledge about the
use of ionising radiation and isotopes within medicine both for
diagosis and for treatment is obtained.
The course will provide the student with a basis for judging the risks and benefits of ionising radiation, both for everyday applications in diagnostics and therapy, as well as in connection to specific incidences, such as accidents or crimal damage.
A few topics of the course provide the studemt with examples of interdisciplinary practice, drawing on results and considerations from physics, chemistry, biology and medicine.
Herman Cember and Thomas E. Johnson, "Introduction to Health Physics", 4th edition, McGraw Hill 2009, plus supplementary notes and scientific papers and reports
- 7,5 ECTS
- Type of assessment
- Oral examination, 30 minOral exam: discussion of scientific paper handed out three days in advance, followed by a brief questioning within one small topic drawn at random.
- Exam registration requirements
Two reports on the experiments performed at Risø DTU should be approved prior to the oral exam.
- All aids allowed
- Marking scale
- 7-point grading scale
- Censorship form
- No external censorship
More internal examiners
Same as regular exam.
If the student did not participate in the experiments he/she cannot take the re-exam but must follow the course again.
If the student participated in the experiments, but the reports were not approved, new reports can be handed in 2 weeks before the re-exam.
Criteria for exam assesment
- Practical exercises
- Theory exercises
- Project work