Sistemas e Técnicas de Detecção de Radiação

Objectives

Understand the physical or chemical underpinnings of radiation detection methods and systems used in radiation protection and safety. Understand the treatment of the resulting electrical signals. Master the principles of data acquisition, statistics and equipment control. Being able to install such detection systems, adjust electrical signals, take measurements and determine their reliability. Be able to identify malfunctions, their screening and propose corrective measures.

Syllabus

• Introduction: Count statistics. Uncertainties and their spread. Limits of detection. Distribution of counting intervals. • Signal treatment and properties of radiation detectors: Transducers. Signal treatment. Noise. Temporal resolution. Detector model. Resolution in energy. Efficiency. Dead time. Single- and multi-channel analyzers. Boost Count. Amplitude measurement. Digital treatment. • Simple detectors: Dash detectors. Photographic film. Fricke detector. • Gas Detectors: Principles. Ionization chambers. Proportional detectors. Geiger regime. Applications. • Scintillation Detectors: Principles. Organic scintillators. Inorganic scintillators. Light detection. Applications. • Photo multipliers and photo diodes • Scintillation Spectroscopy • Diode Detectors: Applications • Germanium Detectors: Principles. Resolution. Applications in gamma spectroscopy. • Neutron detection: Slow neutron detection. Fast neutron detection • Other detectors

Prerequisites

• Knowledge in radiation physics (nuclear radiation origin, types, radiation interactions, cross sections, units and dosimetry quantities). • Knowledge in probability and statistics: distributions, models, error propagation, linear regression. • Basic knowledge of data processing and representation of scientific results. Experience with programs or routines suitable for data analysis.

Cross Competence Component

The UC allows the development of the following transversal competences: • Critical and innovative thinking: through problem solving and analysis of experimental results and the autonomous and critical choice of bibliography for the final work; • Interpersonal skills: teamwork in the realization of practical work and joint reporting; • Intrapersonal skills: promoting the discipline necessary to meet deadlines for problem series and experimental reports; • Information and media literacy: by seeking and selecting information for the preparation of experimental reports and preparation of the final presentation. The assessment percentage associated with these skills should be in the order of 20%.

Laboratorial Component

Accomplishment of 8 practical works: • Coaxial cables. Pulse and linear generators. Multichannel Assembly and adjustment of a measurement chain • Fricke dosimeter: determination of the calibration curve of a Co-60 installation. • Liquid organic scintillators: radon measurement • Characterization of a Geiger detector • Gamma spectrometry with INa (Tl) and CZT detectors • Alpha Spectrometry • HPGe diode detector spectrometry • neutron detection

Ethical Principles

All members of a group are responsible for the group´s work. In any assessment, every student shall honestly disclose any help received and sources used. In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.