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

Oxygen, nitrogen and methane purification efficiencies for a common zirconium getter are measured in 1050 Torr of xenon gas. Starting with impurity concentrations near 10−6 g/g, the outlet impurity level is found to be less than 120 ×10−12 g/g for O2 and less than 950×10−12 g/g for N2. For methane we find residual contamination of the purified gas at concentrations varying over three orders of magnitude, depending on the purifier temperature and the gas flow rate. A slight reduction in the purifier's methane efficiency is observed after 13 mg of this impurity has been absorbed, which we attribute to partial exhaustion of the purifier's capacity for this species. We also find that the purifier's ability to absorb N2 and methane can be extinguished long before any decrease in O2 performance is observed, and slower flow rates should be employed for xenon purification due to the cooling effect that the heavy gas has on the getter.

/pdf/study-of-a-zirconium-getter-for-purification-of-xenon-gas-2gxig11ss7.pdf

Study of a zirconium getter for purification of xenon gas

A method for monitoring the unknown contents in a volume comprises the steps of sending gamma radiation and/or fast neutrons emerging from said volume through a measuring volume (12) of at least one radiation detector (10), said measuring volume (12) containing a noble gas or a mixture of noble gases; counting the photons generated within said measuring volume (12) by an interaction (18) of the gamma radiation and/or fast neutrons with the noble gas or noble gases of the measuring volume (12) by means of photon counters (15, 16); deriving from the output of said photon counters (15, 16) a spectrum of the radiation passing through the measuring volume, wherein neutrons and gamma rays are discriminated by their different pulse shapes; and processing said derived spectrum to gain information about the unknown contents in said volume.

Method for monitoring an unknown container or the contents in a volume, monitoring system for being used with said method, and radiation detector for such a monitoring system

In past years, liquid rare gas detectors (LRGD) have made a considerable progress and found application in various fields of research, such as high energy experiments, astrophysics, search for rare processes and medical imaging. This review paper starts by a short summary and discussion of the properties of liquid rare gases (LRG) that make them attractive as radiation detector media. Next, the two best-established technologies based on liquid rare gases, electromagnetic calorimeters and time projection chambers, are briefly reviewed along with their main applications. The bulk of the paper is focused on the challenging development of LRGD for the search of rare processes in low background experiments with an emphasis on those dealing with the direct detection of dark matter. The challenges posed by those experiments, the detectors proposed and their present status of development are described. A brief review of the proposals of using LRGD for medical imaging is outlined and the present status of some of the more significant developments under way is presented.

Liquid rare gas detectors: recent developments and applications

An emission detector, self-triggered with scintillation is proposed to search for double-beta positron decays of /sup 124/Xe and /sup 78/Kr.

An electroluminescence emission detector to search for double-beta positron decays of /sup 124/Xe and /sup 78/Kr

The spark disharge method of liquid rare-gas purification is describe. The method is sufficiently more simple than those widely used. Physical aspects of the method are discussed, and examples of its application are presented.

/pdf/spark-discharge-method-of-liquid-rare-gas-purification-28nyva3bfu.pdf

S. G. Pokachalov

Papers

Spark discharge method of liquid rare-gas purification

Radiation-stable ionizing-radiation detectors working with liquid rare gases