Chapter 3 Basic Instrumentation for Nuclear Technology Outline of experiment 1. Accelerators get particles(e.g. protons,.) 2. Detectors accelerate them throw them against each other observe and record what happens 3. Reactors analyse and interpret the data
Chapter 3. Basic Instrumentation for Nuclear Technology 1. Accelerators 2. Detectors 3. Reactors Outline of experiment: • get particles (e.g. protons, …) • accelerate them • throw them against each other • observe and record what happens • analyse and interpret the data
1. Accelerators History-Why Particle sources Acceleration stage Space charge Diagnostics Application
• History-Why • Particle Sources • Acceleration stage • Space charge • Diagnostics • Application 1.Accelerators
2. Detectors Gas-Filled Radiation Detectors ionization chambers proportional counters Geiger-Muller counters Scintillation Detectors Photomultiplier tube Semiconductor detectors photographic films Personal dosimeters photographic emulsion plates Others Cloud and bubble chambers Particle identification E-△E.TOF Measurement theory Detection Equipment
Gas-Filled Radiation Detectors Scintillation Detectors Semiconductor Detectors Personal Dosimeters Others Particle identification Measurement theory Detection Equipment ionization chambers proportional counters Geiger-Muller counters E-ΔE, TOF photographic films photographic emulsion plates Cloud and Bubble Chambers Photomultiplier tube 2. Detectors
lonization chambers Key Components in a Simple ionization Chamber lonizing Battery the voltage must be radiation sufficiently high for effective collection of Ⅰoad electrons +? resister 109(eVs1)×1.6×109( C per ion Detector 34(ev per ion Ampere chamber meter ≈5×10-12A The average energy required to Current(A) is proportional to charges collected ionize a gas atom 30 eVion If particles entering an air-filled on electrode in ionization chambers detector deposit an average of The current registered in the ionization chamber is 1 GeV S-1 in the gas, the average current flowing through proportional to the number of ion pairs generated by the chamber radioactivity
Ionization Chambers Key Components in a Simple Ionization Chamber ??? +? ? + – Amperemeter Detector chamber Ionizing radiation Battery Load resister Current (A) is proportional to charges collected on electrode in ionization chambers. The current registered in the ionization chamber is proportional to the number of ion pairs generated by radioactivity the voltage must be sufficiently high for effective collection of electrons. The average energy required to ionize a gas atom 30 eV/ion. If particles entering an air-filled detector deposit an average of 1 GeV S-1 in the gas, the average current flowing through the chamber
How can the sensitivities of ionization chambers be improved? What happens when the voltage is increased? Proportional Counters Gas Multiplication Key Components in a Simple lonization Chamber Io XOO V Load 一十-+十 Detector Amp chamber meter 十一十一十+十一+一十+一 Proportional counters +-+-+-+-+-+-+-+-+-+-+ Gas multiplication due to +-+-+-+-+-+-+-+-+-+-+-+-secondary ion pairs when the +-+-+-+-+-+-+-+-+-+-+-+-ionization chambers operate at 十 higher voltage not only collect but also accelerate electrons
5 Proportional Counters Key Components in a Simple Ionization Chamber ??? +? ? + – Amperemeter Detector chamber Ionizing radiation Battery Load resister Gas Multiplication –+ –+–+–+ –+–+–+–+–+–+–+–+–+ –+–+–+–+–+–+–+–+–+–+–+– +–+–+–+–+–+–+–+–+–+–+–+– +–+–+–+–+–+–+–+–+–+–+–+– + Proportional counters Gas multiplication due to secondary ion pairs when the ionization chambers operate at higher voltage. X00 V How can the sensitivities of ionization chambers be improved? What happens when the voltage is increased? not only collect but also accelerate electrons