Detectors of Ionizing Radiation
- Petr Průša (guarantor)
- Department of Dosimetry and Application of Ionizing Radiation
Gas filled detectors (ionization chambers, proportional counters, Geiger-Müller counters, corona counters), organic and inorganic scintillation detectors, Cherenkov counters, evaluation of light by photomultiplier, parameters of PMT, semiconductor detectors, cryogenic detectors.
- Syllabus of lectures:
1. Types of gas filled detectors, energy dissipation per ion pair w, design and operation of the dc or pulse operating ion chambers, formation of negative ions, charge carriers diffusion, recombination and movement, velocity in electric field in various gases and their mixtures.
2. DC mode of IC - saturated current, recombination/diffusion losses - dynamic response, current fluctuation, use of DC working IC to measure of basic dosimetric quantities (gamma ray exposure, kerma, absorbed dose, activity)
3. Pulse mode of IC - carrier collection time, derivation of the pulse shape, pulse amplitude dependency on interaction coordinate in parallel plate, coaxial and spherical IC with full or electron only collection. Fission and gridded pulse chambers.
4. Proportional counters - Townsend avalanche formation, gas multiplication factor, and the Diethorn parameters for proportional gases, space charge effects and energy resolution as result of statistical fluctuation of created ion pairs and gas multiplication factor, Fano factor.
5. Pulse shape of proportional counter - resolution time, counting characteristic, detection efficiency. Different types of PC - 2 or 4 pi windowless, window, gas flow/closed, use of PC for counting and absolute activity measurement alpha/beta. X-Ray counting and spectrometry, beryllium thin windows.
6. Neutron detection and spectrometry by means of nuclear reactions 10B(n,alpha)7Li, 3He(n,p)3H and elastic scattering n,p (hydrogen) in proportional counters, shape and unfolding of spectrum, wall effect, spurious pulses.
7. Principle of Geiger-Mueller counters, external/internal (alcohol/halogen) quenching, counter's live time, counting plateau, dead/recovery time, and service life. Types of GM counters and their detection efficiency for different ionizing radiation.
8. Corona counter - theory of corona discharge, detection of slow energy neutrons through fission or reaction 10B(n,alpha)7Li, non sensitivity to gamma rays. Preliminary of the scintillation detectors. Organic/inorganic detectors
9. Primary and secondary scintillation process in organic scintillators, energy levels of pi - electrons, radiation/no radiation transition, fluorescence, phosphorescence, delayed fluorescence. Radiative and nonradiative migration of excitation energy -- self-absorption. One and multi component organic scintillators. Conversion efficiency, emission spectra, time constant of light emission, dependency on the types of radiation.
10. Exploitation of organic (solid and/or liquid) scintillators - betas and neutron detection and spectrometry, n - gamma pulse shape discrimination. Classification of inorganic scintillators - pure and activated alkali halides monocrystals - BGO, polycrystalline, glass, and gaseous scintillators. Basic properties, using inorganic scintillators.
11. Cerenkov detector - principle, threshold, differential types. Processing and registration of light photons from detectors - reflection coating, light guides, immersion layer, photo multiplier, and semiconductor light sensitive elements. Dynodes´ multiplication system, construction and shapes.
12. Semiconductor detectors - prompt theory - using p-n junction as detector of charged particles, thickness of depletion region, entrance window, position sensitive Si detectors, technologies of production. P-I-N planar or coaxial structures (Li compensated, HPGe) as photon detector, detector cooling. Detectors from the other semiconductor materials than Si and Ge. Typical properties of semiconductor detectors.
13. Cryogenic detectors (Principle of cryogenic detectors, superconducting tunnel junctions).
- Syllabus of tutorials:
- Study Objective:
Principles of ionizing radiation detection, Basic applications of detectors of ionizing radiation, Basics of construction of ionizing radiation detectors
Skills: Orientation in the covered topic, evaluation of detector parameters, choice of detectors for given application
- Study materials:
 Gerndt, J.; Průša, P.: Detektory ionizujícího záření. 2. přepracované vydání. Vydavatelství ČVUT, Praha, 2011.
 Knoll, G.F.: Radiation Detection and Measurement. John Wiley & Sons, 4th edition, 2010
 S.N. Ahmed: Physics & Engineering of Radiation Detection, Elsevier, 2nd edition, 2015
 P. Rodnyi: Physical Processes in Inorganic Scintillators,CRC Press, 1997
 B.B. Rossi: Ionization Chambers and Counters, McGraw-Hill, New York, 2010
 H. Spieler: Semiconductor Detector Systems, Oxford University Press, 2005
- Time-table for winter semester 2020/2021:
- Time-table is not available yet
- Time-table for summer semester 2020/2021:
- Time-table is not available yet
- The course is a part of the following study plans: