Foreword. Preface. Acknowledgements. 1 Introduction. 1.1 Units and Definitions. 1.2 Brief History of Noble Gas Detectors. 2 Noble Fluids as Detector Media. 2.1 Physical Properties of Dense Noble Gases. 2.2 Energy Dissipation in Noble Gases. 2.3 Ionization Clusters and Principal Limitations on Position Resolution of Noble Gas Detectors. 2.4 Ionization and Recombination. 2.4.1 Jaffe Model of Recombination. 2.4.2 Onsager Model of Recombination. 2.4.3 Influence of a-Electrons. 2.5 Principal Limitations for Energy Resolution. 2.6 Detection of Nuclear Recoils. 2.7 Detection of High-Energy Particles. 3 Elementary Processes Affecting Generation of Signals. 3.1 Collection of Charge Carriers. 3.1.1 Charge Carrier Drift in Gases Under High Pressure. 3.1.1.1 Drift of Electrons in Gases. 3.1.1.2 Drift of Ions in Gases. 3.1.2 Drift of Charge Carriers in Condensed Phases. 3.1.2.1 Drift of Electrons in Condensed Phases. 3.1.2.2 Drift of Ions and Holes in Condensed Noble Gases. 3.1.3 Charge Carrier Trapping. 3.1.3.1 Electron Attachment in Liquids. 3.1.3.2 Charge Trapping in Solids. 3.2 Electron Multiplication and Electroluminescence. 3.3 Charge Carrier Transfer at Interfaces. 3.3.1 Quasifree Electron Emission. 3.3.1.1 Thermal Electron Emission. 3.3.1.2 Hot Electron Emission. 3.3.1.3 Transition of Quasifree Electrons Along Interface. 3.3.2 Electron Emission From Localized States. 3.3.3 Transitions Between DifferentMedia. 3.3.4 Ion Emission from Nonpolar Dielectrics. 3.3.5 Electron Emission into Nonpolar Dielectrics. 3.3.5.1 Electron Emission From Cathodes. 3.3.5.2 Electron Injection Through the Free Interface. 3.4 Properties of Noble Gas Scintillators. 3.4.1 Primary Processes. 3.4.2 Emission Spectra. 3.4.2.1 Emission Spectra of Gases. 3.4.2.2 Emission Spectra of Liquids and Solids. 3.4.3 Absorption and Scattering. 3.4.3.1 Self-Absorption. 3.4.3.2 Impurity Absorption. 3.4.3.3 Scattering. 3.4.4 Scintillation Light Yield. 3.4.5 Refractive Index. 3.4.6 Decay Times. 3.4.6.1 Decay Times of Gases. 3.4.6.2 Decay Times of Liquids and Solids. 4 Scintillation Detectors. 4.1 High-Pressure Noble Gas Scintillation Detectors. 4.1.1 Single-Channel Gas Scintillation Detectors. 4.1.2 Multichannel Gas Scintillation Detectors. 4.2 Condensed Noble Gas Scintillation Detectors. 4.2.1 Scintillation Detectors Using Liquid Helium and Condensed Neon. 4.2.2 Scintillation Detectors Using Liquid Argon, Krypton and Xenon. 4.2.2.1 Single-Channel Noble Liquid Scintillation Detectors. 4.2.2.2 Multichannel Noble Liquid Scintillation Detectors. 4.3 Development of Scintillation Calorimeters. 4.3.1 Granulated Scintillation Calorimeters. 4.3.1.1 UV Light-Collecting Cells. 4.3.1.2 Light-Collecting Cells withWavelength Shifter. 4.3.1.3 Scintillation Calorimeter LIDER. 4.3.2 Barrel Scintillation Calorimeters. 4.4 Time-of-Flight Scintillation Detectors. 5 Ionization Detectors. 5.1 Generation of Induction Charge. 5.2 Diode Ionization Chamber. 5.3 Triode Ionization Chamber. 5.4 Multilayer Ionization Chamber. 5.5 Ionization Chamber with Virtual Frisch Grid. 5.6 Time Projection Chamber with Scintillation Trigger. 5.7 Use of Both Ionization and Scintillation Signals. 6 Proportional Scintillation Detectors. 6.1 Gaseous EL Detectors with Parallel Plate Electrode Structure. 6.1.1 Gas Proportional Scintillation Counters. 6.1.1.1 GPSCs with PMT Readout. 6.1.1.2 GPSC with Photodiode Readout. 6.1.1.3 GPSC with Open Photocathode Readout. 6.1.2 High-Pressure Electroluminescence Detectors. 6.1.3 Imaging Electroluminescence Detectors. 6.1.3.1 Analog Imaging Electroluminescence Detectors. 6.1.3.2 Digital Imaging. 6.2 High-Pressure Xenon Electroluminescence Detectors with Nonuniform Electric Field. 6.2.1 Cylindrical Proportional Scintillation Counters and Drift Chambers. 6.2.2 Gas Scintillation Proportional Counters with Spherical Electrical Field. 6.3 Multilayer Electroluminescence Chamber. 6.4 Liquid Electroluminescence Detectors. 7 Two-Phase Electron Emission Detectors. 7.1 Emission Ionization Chambers. 7.2 Emission Proportional Chambers. 7.3 Emission Spark Chambers. 7.4 Emission Electroluminescence Detectors. 7.5 Vacuum Emission Detectors. 7.6 Further Developments of Two-Phase Detectors. 8 Technology of Noble Gas Detectors. 8.1 Selection of Materials and Mechanical Design. 8.1.1 Metals. 8.1.1.1 Construction Metals. 8.1.1.2 Sealings. 8.1.2 Insulators. 8.1.3 Feedthroughs. 8.1.3.1 Electrical Feedthroughs. 8.1.3.2 Optical Fiber Feedthroughs. 8.1.3.3 Motion Feedthroughs. 8.1.4 Electrodes. 8.1.4.1 Active Cathodes. 8.1.4.2 Grids. 8.1.4.3 Multilayer Structures. 8.1.4.4 Amplifying Electrode Structures. 8.1.5 Viewports andWindows. 8.1.5.1 Materials. 8.1.5.2 Optical Windows for High-Pressure Detectors. 8.1.5.3 Glass Machining. 8.1.6 High-Pressure Vessels. 8.1.7 Cryogenics. 8.2 Processing High Purity Noble Gases. 8.2.1 Pretreatment. 8.2.2 Pumping. 8.2.3 Baking. 8.2.4 Handling. 8.3 Purification. 8.3.1 Impurities. 8.3.2 Chemical Methods of Purification. 8.3.3 Electron Drift Purification Method. 8.3.4 Spark Purification. 8.3.5 Separation of Noble Gases. 8.3.6 Circulation. 8.4 Monitoring the Working Media. 8.4.1 Electron Lifetime. 8.4.2 Optical Transparency. 8.4.3 Mass and Position of Free Surface. 8.4.4 Temperature, Pressure, and Density. 8.5 UV Light Collection. 8.5.1 Reflectors. 8.5.2 Wavelength Shifters. 8.5.2.1 Wavelength Shifters Dissolved in Noble Gases. 8.5.2.2 Solid Wavelength Shifters. 8.6 Photosensors. 8.6.1 Photomultipliers. 8.6.1.1 Low Temperature. 8.6.1.2 PMTs for High Pressure. 8.6.2 Semiconductor Photodiodes. 8.6.3 Open Photocathodes. 9 Applications. 9.1 Astronomy. 9.1.1 Instrumentation for X-ray Astronomy. 9.1.1.1 Gas Imaging Spectrometers On-Board ASCA. 9.1.1.2 High-Pressure Gas Scintillation Proportional Counter at BeppoSAX. 9.1.1.3 High-Pressure Gas Scintillation Proportional Counter On-Board HERO. 9.1.2 Instrumentation for Gamma Ray Astronomy. 9.1.2.1 KSENIA On-Board MIR Orbital Station. 9.1.2.2 LXeGRIT Balloon-Borne Compton Telescope. 9.2 Low-Background Experiments. 9.2.1 Direct Detection of Particle Dark Matter. 9.2.2 Neutrino Detectors. 9.2.3 Double Beta and Double Positron Decay Search. 9.2.3.1 Experiments with Active Targets. 9.2.3.2 Experiment with a Passive Target. 9.2.3.3 Double Positron Decay Experiments. 9.3 High-Energy Physics: Calorimeters. 9.3.1 Ionization Calorimeters. 9.3.1.1 Liquid Argon Calorimeters. 9.3.1.2 Liquid Krypton Calorimeters. 9.3.1.3 Xenon Calorimeters. 9.3.2 Scintillation Calorimeters. 9.4 Medical Imaging. 9.4.1 X-ray Imaging. 9.4.1.1 Analog X-ray Imaging. 9.4.1.2 Digital X-ray Imaging. 9.4.2 Single-Photon Emission Computing Tomography (SPECT). 9.4.2.1 Liquid Xenon Detectors for SPECT. 9.4.2.2 High-Pressure Noble Gas Detectors for SPECT. 9.4.3 Positron Emission Tomography (PET). 9.4.3.1 Liquid Xenon TPC with a Scintillation Trigger. 9.4.3.2 Liquid Xenon Scintillation Time-of-Flight PET. References. Index.

Noble Gas Detectors

A high-pressure xenon gas TPC can provide both event topology information and optimized energy resolution for the detection of ββ decay in 136Xe. The result of optimization indicates that, at the 136Xe Q-value of 2480 keV, an energy resolution of δE/E<5×10−3 FWHM may be realizable, even at the 1000 kg scale. Signal detection by electroluminescence appears essential to realize this performance. A specific method for generation and detection of the electroluminescent signal and particle tracking in high-pressure xenon gas is advanced. Strengths and weaknesses of high-pressure xenon gas TPC detectors are evaluated and compared to detectors based on liquid xenon.

High-pressure xenon gas electroluminescent TPC for 0-ν ββ-decay search

Gaseous media may efficiently convert into photons the energy losses of particles and the energy supplied by electric fields to drifting electrons. Some mechanisms associated with the process of light production, in particular the two continua and a few energy transfer phenomena, are considered. The relevance of these processes to control the spectral distribution of the photons, and consequently to its detection, and their interest for the time characteristics and the energy resolution capabilities of detecting devices are also referred to. A few examples are presented of instrumental results that either reflect important characteristics of gas scintillation counters, or point to further possible developments, as regards energy, time and position resolutions.

Light Production and Gaseous Detectors

Distributions of the number of primary electrons produced per incident mono-energetic x-rays in the 1- to 41-keV energy range, which includes the xenon L- and K-absorption edges, were simulated in xenon gas detectors with the Monte Carlo technique. These simulated full-energy absorption distributions are calculated as frequency plots of the number of primary electrons produced per incident x-ray photon. The simulation includes the absorption of x-rays and the de-excitation of the residual xenon ions, followed by the development of the primary electron cloud. The discontinuities observed in the Fano factor, w-value, energy linearity and energy resolution reflect the discontinuities of the Xe photoionization cross-section at the photoabsorption edges. The simulation results are compared with experimental values measured with a gas proportional scintillation counter, and with recent data from other authors. The discontinuities in energy linearity produce an ambiguity in determining the x-ray energy in certai...

Full-energy absorption of x-ray energies near the Xe L- and K-photoionization thresholds in xenon gas detectors: Simulation and experimental results

Emission spectra from ArXe, ArKr, ArN2, ArCH4, ArCO2 and XeN2 gas scintillation proportional counters

A large area, gas scintillation proportional counter

A focusing gas scintillation proportional counter

The problems of developing large-area, gas-scintillation proportional counters with high resolution are considered. It is found that simple large-area, parallel-grid proportional counters suffer from a variation in gain over the counter window. Some success has been achieved in overcoming this problem by focusing the charge cloud as it drifts into the multiplication region. Measurements are reported for various mixtures of argon and xenon as well as pure xenon.

Recent Developments in Parallel-Grid, Gas-Scintillation Proportional Counters

An improved large-area gas scintillation proportional counter has been built, suitable for use in X-ray astronomy. This counter employs electron focusing in a drift region to achieve uniform response. We show that we can obtain a spectral resolution of 9.1% FWHM at 5.9 keV over a useful area of 100 cm2. We demonstrate that signal rise-time discrimination can be used to reject non-X-ray background as efficiently as in ordinary proportional counters.

A Large-Area Gas Scintillation Proportional Counter for X-Ray Astronomy

An improved, large-area (285 cm2), gas scintillation proportional counter with a measured overall energy resolution of 9.3% (FWHM) at 5.9 keV has been built. The rise-time resolution, 11.6% (FWHM) at 5.9 keV, of this counter is sufficiently well defined to allow the use of pulse-shape discrimination to reject 86% of the non-X-ray background events, while accepting 80% of the true X-ray events. This counter thus represents a significant advancement over conventional gas proportional counters and should prove extremely useful for X-ray astronomy.

D.F. Anderson

Papers

A large area, gas scintillation proportional counter

A focusing gas scintillation proportional counter

Recent Developments in Parallel-Grid, Gas-Scintillation Proportional Counters

A Large-Area Gas Scintillation Proportional Counter for X-Ray Astronomy

An Improved Large-Area, Gas Scintillation Proportional Counter