Computational Experiments Of Radiations Physics

Portuguese and English Edition  by Lucas Paixão  (Author), Telma Fonseca  (Author)

ABSTRACT 

Teaching and research in nuclear instrumentation and detection are based on the concepts of radiation physics. An instrumentation and detection course depends on a laboratory structure with appropriate sources, detectors, and electronic equipment, which can be a complex undertaking and is not always possible. One way to overcome the difficulties of setting up an instrumentation laboratory is to establish a computer laboratory or virtual laboratory, which allows multiple experiments to be performed and becomes an extremely valuable didactic tool for teaching and exploring the major physical concepts in the field of radiation science.

The proposed computer experiments are based on the physical principles covered in Medical Physics, Radiologic Technology, and Nuclear Engineering courses related to Radiology, Radiotherapy, Nuclear Medicine, Radiation Protection, and Nuclear Instrumentation. Replacing an instrumentation laboratory, with all its experimental apparatus, with computational models is quite audacious, therefore, it is not the intention of this book. The purpose is to complement and enrich the didactic material used in teaching and research, inserting the use of computational tools to solve problems found in laboratory practices. And, for this purpose, the Monte Carlo method will be used as a study tool.

The exercises have been developed to promote understanding of the physical phenomena studied in a course on Radiation Physics or in a nuclear instrumentation laboratory. In this way, students do not need advanced knowledge of the Monte Carlo code used. However, it is expected that the professor using this material to teach a subject, or the graduate student or undergraduate student using it in their learning process, has a minimum of computational skills and some experience with the Monte Carlo code used to perform the experiments, even if you are a novice. It is desirable that all (teachers and students) have a basic knowledge of electronic spreadsheets.

The first experiment, radioactive emission spectra, deals with the simulation of the emission of a radioactive source. The second experiment deals with count statistics and simulates a counting measurement of a radioactive sample. Next, we discuss dosimetric quantities that are important for describing radiation fields. The inverse square law of distance is addressed in the fourth experiment, where we try to verify its strictly geometric character. The fifth experiment deals with the law of photon attenuation, where we discuss its exponential behavior. In the sixth experiment, we study the variation of scattering as a function of relevant parameters. In the seventh experiment, we approach the fundamental dosimetric quantity, the absorbed dose in the practice of dosimetry in radiotherapy. The discussion of charged particle interaction is given in the eighth experiment, where an estimation of the range of electrons is proposed. Finally, the ninth experiment deals with the simulation of a neutron source.