The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform
Rudolf Decher - One of the best experts on this subject based on the ideXlab platform.
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Instrumentation for X-ray astronomy
Space Science Reviews, 1994Co-Authors: Brian D. Ramsey, Robert A. Austin, Rudolf DecherAbstract:Less than five decades ago, the first X-ray observations of the sky were made using simple devices such as film and Geiger Counters with crude collimators. These instruments were carried aloft by sounding rockets and made observations lasting only a few minutes at most. Today, orbiting observatories, utilizing high-resolution CCDs at the focus of arc sec optics, have lifetimes measured in years. To maintain the pace of discovery in X-ray astronomy, detectors must continue to evolve into devices of ever increasing sensitivity and sophistication. Further progress depends upon a host of technologies: grazing incidence optics, proportional Counters, semiconductors, calorimeters, etc. In this article we present a brief qualitative overview of these technologies and of the principles behind them, as well as some examples of how they are employed in scientific missions for X-ray observations at energies up to 100 keV.
Brian D. Ramsey - One of the best experts on this subject based on the ideXlab platform.
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Instrumentation for X-ray astronomy
Space Science Reviews, 1994Co-Authors: Brian D. Ramsey, Robert A. Austin, Rudolf DecherAbstract:Less than five decades ago, the first X-ray observations of the sky were made using simple devices such as film and Geiger Counters with crude collimators. These instruments were carried aloft by sounding rockets and made observations lasting only a few minutes at most. Today, orbiting observatories, utilizing high-resolution CCDs at the focus of arc sec optics, have lifetimes measured in years. To maintain the pace of discovery in X-ray astronomy, detectors must continue to evolve into devices of ever increasing sensitivity and sophistication. Further progress depends upon a host of technologies: grazing incidence optics, proportional Counters, semiconductors, calorimeters, etc. In this article we present a brief qualitative overview of these technologies and of the principles behind them, as well as some examples of how they are employed in scientific missions for X-ray observations at energies up to 100 keV.
Francesco Riggi - One of the best experts on this subject based on the ideXlab platform.
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Cosmic rays with portable Geiger Counters: from sea level to airplane cruise altitudes
European Journal of Physics, 2009Co-Authors: F. Blanco, Paola La Rocca, Francesco RiggiAbstract:Cosmic ray count rates with a set of portable Geiger Counters were measured at different altitudes on the way to a mountain top and aboard an aircraft, between sea level and cruise altitude. Basic measurements may constitute an educational activity even with high school teams. For the understanding of the results obtained, simulations of extensive air showers induced by high-energy primary protons in the atmosphere were also carried out, involving undergraduate and graduate teaching levels.
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Educational cosmic ray experiments with Geiger Counters
Nuovo Cimento Della Societa Italiana Di Fisica C-colloquia on Physics, 2006Co-Authors: F. Blanco, F. Fichera, P. La Rocca, F. Librizzi, O. Parasole, Francesco RiggiAbstract:Experiments concerning the physics of cosmic rays offer to high-school teachers and students a relatively easy approach to the field of research in high energy physics. The detection of cosmic rays does not necessarily require the use of sophisticated equipment, and various properties of the cosmic radiation can be observed and analysed even by the use of a single Geiger counter. Nevertheless, the variety of such kind of experiments and the results obtained are limited because of the inclusive nature of these measurements. A significant improvement may be obtained when two or more Geiger Counters are operated in coincidence. In this paper we discuss the potential of performing educational cosmic ray experiments with Geiger Counters. In order to show also the educational value of coincidence techniques, preliminary results of cosmic ray experiments carried out by the use of a simple coincidence circuit are briefly discussed.
Yogesh B Gianchandani - One of the best experts on this subject based on the ideXlab platform.
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From Antenna Stents to Wireless Geiger Counters: The Promise of Electrical Micro-Discharges in the Fabrication and Operation of Microsensors
2006 IEEE International Symposium on MicroNanoMechanical and Human Science, 2006Co-Authors: Yogesh B GianchandaniAbstract:Micro-scale electrical discharges can be useful in both manufacturing contexts and sensing modalities. With regard to manufacturing, they provide structural and material diversity: microplasmas ignited between thin film metal patterns permit localized etching and deposition, whereas micro-arcs permit stainless steel and other bulk metals. Micro-electrodischarge machining has been used for the lithography-compatible fabrication of "smart stents" that are integrated with pressure sensors. It has also been used to embed sensors at the tip of biopsy needles. With regard to sensing modalities, spectroscopic detection of chemicals in both gas and liquid phase has been explored. For example, discharge spectroscopy has been used to detect inorganic contaminants such as lead and chrome in water. The converse application has also been reported: salts dissolved in aqueous sample are used to tune the emission spectrum, which is subsequently filtered and used as an inexpensive UV source for the fluorescent detection of biochemicals. Gas-phase discharges are used for radiation sensing by Geiger Counters and related micromachined devices. It has been shown that the RF emissions associated with these discharges are in the UWB spectrum, and can be detected by common AM/FM radios, creating some interesting opportunities for wireless networking.
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controlling ultra wide band transmissions from a wireless micromachined Geiger counter
International Conference on Micro Electro Mechanical Systems, 2006Co-Authors: Ranjit Gharpurey, Yogesh B GianchandaniAbstract:This paper reports a parametric study of the wireless spectrum generated by discharge-based devices with focus specifically on micromachined Geiger Counters as a function of the packaging, biasing circuitry, and sample isotope. Experiments are conducted with discharge devices attached to commercial high voltage (HV) packages with hermetic sealing capabilities. Influences of packaging as well as isotope type are studied and reported. Preliminary results show that current discharges emit RF spectra spanning a bandwidth greater than 3 GHz, which extends into the ultra wideband (UWB) window (from 100 MHZ to 10.6 GHz) that decreases in intensity with increasing observer distance.
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D-MICROGeiger: A MICROFABRZCATED BETA-PARTICLE
2005Co-Authors: Chester G. Wilson, Christine K. Eun, Yogesh B GianchandaniAbstract:This paper reports on micromachined Geiger Counters fabricated from stacks of glass and Si wafers. As a beta particle passes through, a bias applied between two enclosed electrodes generates electron cascades in the gas between them, This results in a current pulse or “count”. A single die of 2 cm’ had 6 independent chambers ranging in size from 8x8 mm2 to 1x3 mm2. Helium and neon, which have different voltage bias requirements, were separately evaluated as -background gases. In tests the device was found to detect incident beta particles from a Uranium-238, and calibrated ?Sr, 6oCo, and ’91 sources, of 0.1-1 yCurie strength. In the D-microGeiger incident beta particles pass through two independent cavities that are separated by a glass barrier, which provides calibrated energy absorption. By comparing the counts in the two cavities, information about the energy of the radiation is determined. This provides an inherent ability to discern the chemical nature of the isotope, not just the presence of radiation.
Robert A. Austin - One of the best experts on this subject based on the ideXlab platform.
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Instrumentation for X-ray astronomy
Space Science Reviews, 1994Co-Authors: Brian D. Ramsey, Robert A. Austin, Rudolf DecherAbstract:Less than five decades ago, the first X-ray observations of the sky were made using simple devices such as film and Geiger Counters with crude collimators. These instruments were carried aloft by sounding rockets and made observations lasting only a few minutes at most. Today, orbiting observatories, utilizing high-resolution CCDs at the focus of arc sec optics, have lifetimes measured in years. To maintain the pace of discovery in X-ray astronomy, detectors must continue to evolve into devices of ever increasing sensitivity and sophistication. Further progress depends upon a host of technologies: grazing incidence optics, proportional Counters, semiconductors, calorimeters, etc. In this article we present a brief qualitative overview of these technologies and of the principles behind them, as well as some examples of how they are employed in scientific missions for X-ray observations at energies up to 100 keV.
