Microstrip Gas Detectors Research Articles

Characterization of a low-pressure Micro-Megas-like gaseous detector with low energy x-ray sources

Within the family of the Micro Strip Gas Detectors (MSGD), the intrinsic characteristics of the bulk Micro-Megas (MM) device represent the most promising features for the construction of a new instrument to be operated as a TPC gas chamber in a low-pressure regime. In this study, we present the main properties of a low-pressure bulk MM detector in which the amplification gap was slightly increased to improve the gas gain. Two configurations have been deeply studied: the first one with a gap of 128μm and a second one with a 192μm gap, both filled and operated with a gas mixture (Ar-CO2) at pressures below 100 mbar. The dependence of the gain and the energy resolution on the amplification field, gas pressure and drift field have been evaluated. The reliability of the measured performance, combined with the simple and robust structure of the detector even with an increased length of amplification gap, make it an attractive choice for applications where the track length of low energy particles is detected by using a low-pressure filling gas.

Synchrotron applications of pixel and strip detectors at Diamond Light Source

A wide range of position-sensitive X-ray detectors have been commissioned on the synchrotron X-ray beamlines operating at the Diamond Light Source in UK. In addition to mature technologies such as image-plates, CCD-based detectors, multi-wire and micro-strip gas detectors, more recent detectors based on semiconductor pixel or strip sensors coupled to CMOS read-out chips are also in use for routine synchrotron X-ray diffraction and scattering experiments. The performance of several commercial and developmental pixel/strip detectors for synchrotron studies are discussed with emphasis on the image quality achieved with these devices. Examples of pixel or strip detector applications at Diamond Light Source as well as the status of the commissioning of these detectors on the beamlines are presented. Finally, priorities and ideas for future developments are discussed.

Development of Two-Dimensional Micro-Strip Gas Detector With Individual Readouts for Neutron Scattering Experiments

We have been developing a Micro-Strip Gas Chamber (MSGC) with individual readouts for neutron scattering experiments. Performance requirements of a two-dimensional position sensitive neutron imaging detector for detecting an accurate Bragg-peak from a sample target include high spatial resolution, high detection efficiency, fast temporal response, and low gamma-ray sensitivity. To meet these specifications in addition to achieving a compact size in spite of the multi-channels in the gas based detector, we constructed a detector system that has a gas vessel with 541 channel feedthrough directly connecting to the data processing circuits. The developed detector system exhibited a pulse pair resolution of less than 1 mus, a spatial resolution of about 0.8 mm in full width at half maximum and good agreement between the position of incident neutron and measured peak position

JEM-X: Joint European X-Ray Monitor

JEM-X is the x-ray monitor for INTEGRAL. It is being built by a large Europeanconsortium led by the Danish Space Research Institute. It consists of two identical,independent coded mask x-ray telescopes with an energy span from 3 keV to60 keV. Each system has a microstrip gas detector and a mask with a 25% transparenthexagonal uniformly redundant pattern based on a bi-quadratic residue setsituated 3.4 m above the detector. The fully illuminated field-of-view is circularand 4.8° across. The mechanical properties and source detection sensitivities are reviewed.

Novel large-area thermal neutron imaging detectors comprising [formula omitted] and micro-strip gas detectors with low-pressure, two-stage amplification and delay line readout

A novel large-area (0.5 × 0.5 m 2) two-dimensional position-sensitive detector for thermal and sub-thermal neutrons is being developed comprising 157 Gd CsI multilayer convertor foils and two fourfold segmented micro-strip gas detector (MSGC) planes for electron multiplication on either side of the convertor. The MSGC operates in low-pressure, two-stage amplification mode; their novel design is optimized for that mode and for obtaining high signals on both coordinates. Fast signal rise times (5–6 ns) and very high gains (∼ 5 × 10 5) are expected according to calculations; thus, simple delay line readout, with one interpolating strip between readout nodes, can be used delivering expected position resolutions <0.5 mm (fwhm) and tolerable count rates of 10 5–10 6 events/s depending on delay line segmentation.

The microdot gas avalanche chamber: an investigation of new geometries

The gains of the microstrip and microgap gas avalanche chambers are limited to below gains of 5 × 10 3 by geometrical and gas properties. In order to increase the maximum gain to greater than 2 × 10 4 a new detector geometry, the microdot, is proposed that can be produced at a standard silicon MOS microfabrication facility at similar cost to present microstrip gas detectors. In addition to charged particle tracking, the new geometry is also well suited to imaging applications. The operating characteristics of the new device have been investigated using a numerical simulation and a comparison with conventional strip geometries is presented. These results show that the microdot geometry reaches higher gas gains than the strip-like geometries, for the same set of electrode potentials, with a reduced cathode electric field enhancing operational stability.

Development of microstrip gas chambers on thin plastic supports

We present the initial measurements realized with microstrip gas detectors on two thin-foil plastic supports, Kapton and Tedlar, having bulk resistivities around 10 17 and 10 14 Ω cm, respectively. Gains up to 10 4 and energy resolutions around 20% FWHM have been obtained in both cases for low rate 5.9 keV X-rays. Long-term and high-flux measurements of gain show time-dependent modifications (charging-up), particularly for the higher resistivity support; nevertheless, the results are very encouraging and further developments may lead to the development of a new family of very light, flexible detectors with high resolution.

Operation of the microstrip gas detector

The article describes the operation of a detector of ionizing particles using metal strips deposited on an insulating substrate to collect and amplify the electrons liberated in the counter gas. It will be demonstrated, that minimum ionizing particles can be well detected with a good accuracy. A number for the stability of the gas gain will be deduced, the upper limit of the gain will be discussed. A circuit to avoid damage by micro-discharges will be presented.