Experimental Techniques in Nuclear and Particle Physics

Experimental Techniques in Nuclear and Particle Physics

Stefaan Tavernier Experimental Techniques in Nuclear and Particle Physics 123

Prof. Stefaan Tavernier Vrije Universiteit Brussel Fak. Wetenschappen Dept. Natuurkunde (DNTK) Pleinlaan 2 1050 Bruxelles Belgium stefaan.tavernier@vub.ac.be ISBN 978-3-642-00828-3 e-isbn 978-3-642-00829-0 DOI 10.1007/978-3-642-00829-0 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2009936050 Springer-Verlag Berlin Heidelberg 2010 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: estudio Calamar S.L. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface I have been teaching courses on experimental techniques in nuclear and particle physics to master students in physics and in engineering for many years. This book grew out of the lecture notes I made for these students. The physics and engineering students have rather different expectations of what such a course should be like. I hope that I have nevertheless managed to write a book that can satisfy the needs of these different target audiences. The lectures themselves, of course, need to be adapted to the needs of each group of students. An engineering student will not question a statement like the velocity of the electrons in atoms is 1% of the velocity of light, a physics student will. Regarding units, I have written factors h and c explicitly in all equations throughout the book. For physics students it would be preferable to use the convention that is common in physics and omit these constants in the equations, but that would probably be confusing for the engineering students. Physics students tend to be more interested in theoretical physics courses. However, physics is an experimental science and physics students should understand how experiments work, and be able to make experiments work. As a post doc, I have never designed any electronics board, but many times I have had to find out why the board I have given did not do what it was supposed to do and fix the problem. This is an essential skill any experimental physicist should have. I hope this book will help the students in acquiring this skill and provide her or him with a sufficient basic knowledge on nuclear and particle detection techniques such that she or he is able to read, and understand, the scientific literature in this field. Brussels, Belgium Stefaan Tavernier v

Contents 1 Introduction... 1 1.1 Documentation... 1 1.2 UnitsandPhysicalConstants... 2 1.3 Special Relativity...... 3 1.4 Probability and Statistics... 7 1.5 The Structure of Matter at the Microscopic Scale.... 9 1.6 Nuclei and Nuclear Decay...... 16 1.6.1 The Beta Decay... 17 1.6.2 The Alpha Decay... 18 1.6.3 The Gamma Decay...... 19 1.6.4 ElectronCaptureandInternalConversion... 19 1.6.5 The Radioactive Decay Law...... 20 1.6.6 TheNuclearLevelDiagram... 21 1.7 Exercises... 22 References... 22 2 Interactions of Particles in Matter... 23 2.1 CrossSectionandMeanFreePath... 23 2.2 Energy Loss of a Charged Particle due to Its Interaction withtheelectrons... 25 2.3 Other Electromagnetic Interactions of Charged Particles..... 31 2.4 InteractionsofX-RaysandGammaRaysinMatter... 39 2.5 InteractionsofParticlesinMatterduetotheStrongForce... 45 2.6 NeutrinoInteractions... 49 2.7 IllustrationsoftheInteractionsofParticles... 51 2.8 Exercises... 53 References... 53 3 Natural and Man-Made Sources of Radiation... 55 3.1 Natural Sources of Radiation..... 55 3.2 UnitsofRadiationandRadiationProtection... 59 3.3 Electrostatic Accelerators... 62 3.4 Cyclotrons... 65 3.5 The Quest for the Highest Energy, Synchrotrons and Colliders.. 72 vii

viii Contents 3.6 Linear Accelerators..... 80 3.7 Secondary Beams...... 90 3.8 Applications of Accelerators..... 93 3.9 Outlook... 99 3.10Exercises... 102 References... 102 4 Detectors Based on Ionisation in Gases... 105 4.1 Introduction to Detectors for Subatomic Particles.... 105 4.2 IonisationandChargeTransportinGases... 107 4.3 IonisationChambers... 111 4.4 Counters with Gas Amplification... 116 4.5 Applications of Counters with Gas Amplification.... 126 4.5.1 Proportional Counters for X-Ray Detection... 127 4.5.2 Gas Counters for the Tracking of High-Energy ChargedParticles... 128 4.5.3 Applications of Gas Counters in Homeland Security... 135 4.6 Recent Developments in Counters Based on Gas Amplification.. 135 4.6.1 Micro-strip Gas Counters (MSGC)... 136 4.6.2 GEM and MICROMEGAS Counters... 137 4.6.3 ResistivePlateChambers... 139 4.7 Exercises... 141 References... 141 5 Detectors Based on Ionisation in Semiconductor Materials... 143 5.1 Introduction to Semiconductors.... 143 5.2 The Semiconductor Junction as a Detector... 150 5.3 Silicon Semiconductor Detectors... 156 5.4 Germanium Semiconductor Detectors..... 159 5.5 Other Semiconductor Detector Materials.... 161 5.6 Exercises... 164 References... 165 6 Detectors Based on Scintillation... 167 6.1 Introduction to Scintillators...... 167 6.2 Organic Scintillators.... 168 6.3 Inorganic Scintillators.... 171 6.4 Photodetectors... 177 6.5 Using Scintillators in the Nuclear Energy Range..... 185 6.6 Applications of Scintillators in High-Energy Physics...... 192 6.7 Applications of Scintillators in Medicine.... 198 6.8 Exercises... 207 References... 207 7 Neutron Detection... 209 7.1 SlowNeutronDetection... 209 7.2 Neutron Detectors for Nuclear Reactors.... 213

Contents ix 7.3 FastNeutronDetection... 216 7.3.1 Detectors for Fast Neutrons Based on Moderation.... 216 7.3.2 Detectors Based on the Observation of the Recoil Nuclei. 218 7.4 Exercises... 224 Reference... 224 8 Electronics for Particle Detectors... 225 8.1 Introduction.... 225 8.2 Impulse Response and Transfer Function.... 230 8.3 AmplifiersforParticleDetectors... 238 8.4 TheThermalNoiseofaResistor... 246 8.5 ResistorandTransistorNoiseinAmplifiers... 253 8.5.1 Noise Contribution of a Parallel Resistor or a Series Resistor 254 8.5.2 NoiseDuetotheFirstTransistor... 258 8.6 Shot Noise..... 262 8.7 Summary and Conclusions...... 266 8.8 Exercises... 268 References... 269 Solutions to Exercises... 271 Annex1:PhysicalConstants... 295 Annex 2: International System of Units..... 296 Annex 3: Atomic and Molecular Properties of Materials...... 297 Annex4:PeriodicTableofElements... 299 Annex 5: Electromagnetic Relations...... 300 Annex 6: Commonly Used Radioactive Sources..... 302 Index... 303