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Contours of constant counting rate and radiation dosages measured by Geiger counter and ionization chamber aboard Explorer VI SATELLITE
D region electron density profiles and corpuscular radiation measured by DC probe and Geiger counter
The current status of X-ray astronomy is surveyed by reviewing observational results and theoretical conclusions gained within the past two years in areas dealing with the quiet-sun, slowly-varying, and burst components of solar X-radiation and with the features of cosmic X-ray sources. Thermal and nonthermal processes responsible for a wide variety of X-ray emission mechanisms in nature are explained, and characteristics of X radiation from specific solar structures are described. Attention is given to the effects of interstellar and intergalactic matter on cosmic X-rays; the properties of galactic and extragalactic X-ray sources; and the specifications of such instruments as gas-filled ionization detectors, proportional counters, Geiger counters, scintillation detectors, photoelectric detectors, polarimeters, collimators, spectrometers, and imaging systems.
Radiation detector design using X-ray diffraction camera and multichannel Geiger counter
Legacy Geiger-Muller (GM) survey meters recovered from fallout shelters have been used by several nuclear scientific societies as part of high school outreach programs. A donated antique instrument helps teachers demonstrate radiological principles, but fails to develop student's electronics skills, generate excitement for nuclear careers, or provide individuals with their own devices to explore the radioactive planet. A simple, affordable GM survey meter built by each student would increase direct engagement while providing hands-on experience with circuit-building, soldering, and computer programming. The inclusion of an affordable single-board computer as a component in the survey meter would enable students to tackle more various computer science and electronics projects, thereby potentially recruiting more students into technology and engineering. This paper details the challenges faced by an interdisciplinary undergraduate team designing an easy-to-assemble smart GM survey meter. Their iterative research, design, and testing process included modification to a basic circuit to enable use of different tube types, component cost reduction, application development, and data communication. The ultimate product of the team's efforts, a survey meter with affordable components and a smartphone application capable of creating radiation maps, is detailed in full.
The objective of this research project is to create a heart rate monitor mobile application (app) that allows the user to receive an accurate heart rate reading by placing their finger on the camera for about fifteen seconds. The app will be designed to read the heart rate through blood flow, and because blood flow is directly proportional with blood pressure, this app will also allow the user to get a blood pressure estimate. This enables anyone to have an understanding of their health issues if any are present. The overall goal to integrate this heart rate and blood pressure monitoring app with a personal dosimeter to build a comprehensive health monitoring app. The personal dosimeter Bluetooth connection function is being developed by another student group at Texas A and M University-Kingsville. This allows a user to transfer radiation readings from the Geiger counter to an iOS device while being able to monitor their health as they are exposed to radiation. This app's Bluetooth Geiger counter and heart rate/blood pressure monitor features would prove beneficial to individuals in the nuclear industry who are exposed to various levels of radiation. The combination of those functions will allow workers to measure their heart rate and blood pressure conveniently and within short periods of time. The people this app can help include nuclear power plant workers, radiology technicians, hazardous materials removal workers, and nuclear medicine technologists. We strive to create a mobile app that will allow a nuclear field worker to have a faster and more efficient health monitoring method. (authors)
X-ray astronomy was born in the aftermath of World War II as military rockets were repurposed to lift radiation detectors above the atmosphere for a few minutes at a time. These early flights detected and studied X-ray emission from the Solar corona. The first sources beyond the Solar System were detected during a rocket flight in 1962 by a team headed by Riccardo Giaccom at American Science and Engineering, a company founded by physicists from MIT. The rocket used Geiger counters with a system designed to reduce non-X-ray backgrounds and collimators limiting the region of sky seen by the counters. As the rocket spun, the field of view (FOV) happened to pass over what was later found to be the brightest non-Solar X-ray source; later designated See X-1. It also detected a uniform background glow which could not be resolved into individual sources. A follow-up campaign using X-ray detectors with better spatial resolution and optical telescopes identified See X-1 as an interacting binary with a compact (neutron star) primary. This success led to further suborbital rocket flights by a number of groups. More X-ray binaries were discovered, as well as X-ray emission from supernova remnants, the radio galaxies M87 and Cygnus-A, and the Coma cluster. Detectors were improved and Geiger counters were replaced by proportional counters, which provided information about energy spectra of the sources. A constant challenge was determining precise positions of sources as only collimators were available.
Solar X-ray flare observed by Geiger counter onboard Explorer XXXIII satellite
Multiple or stacked detectors and single fixed detector - improved X-ray vidicon, operation of flat plate Geiger counter, electronic readout system, and Seeman-Bohling focusing camera
Three cosmic X-ray source locations determined, using rocket mounted Geiger counters
Periodic modulations of energetic electron fluxes observed throughout distant radiation zone by Geiger counters aboard satellites suggest MHD WAVE activity
Properties of Van Allen outer radiation belt determined by ion chamber and Geiger counter instruments aboard Explorer VI satellite
Mariner space probe ionization chamber and Geiger counter experiments on galactic radiation entering solar system
Van allen belt - inner belt radiation data from ion chamber and geiger counter aboard explorer vi satellite
Single-ion detection has, for many years, been the domain of large devices such as the Geiger counter, and studies on interactions of ionized gasses with materials have been limited to large systems. To date, there have been no reports on single gaseous ion interaction with microelectronic devices, and single neutral atom detection techniques have shown only small, barely detectable responses. Here we report the observation of single gaseous ion adsorption on individual carbon nanotubes (CNTs), which, because of the severely restricted one-dimensional current path, experience discrete, quantized resistance increases of over two orders of magnitude. Only positive ions cause changes, by the mechanism of ion potentialinduced carrier depletion, which is supported by density functional and Landauer transport theory. Lastly, our observations reveal a new single-ion/CNT heterostructure with novel electronic properties, and demonstrate that as electronics are ultimately scaled towards the one-dimensional limit, atomic-scale effects become increasingly important.
Purpose: Y-90 Selective Internal Radiation Therapy (SIRT) is used to treat liver tumors, and by nature has variability in the percent of the intended dose that is actually delivered. To determine the quality of the administration, pre and post activity measurements are taken, and used to infer percent delivered. Vendor specifications indicate the use of an ion chamber to take these measurements. In our work, we investigated the accuracy of ion chambers, and compared them to other detector systems. Methods: We have built phantoms, phantom holders, and protocols, which allow us to measure our Y90 doses with varying apparatuses: a dose calibrator, a Geiger-counter, an ion chamber, a crystal based thyroid probe, and a gamma camera. We have set up a system that has enabled us to gather data by measuring clinical Y90 doses as they are used in the clinic using all of the instrumental methods. Five initial doses (25 measurements/acquisitions) have been taken at the time of this abstract submission. Results: Our initial results show that measurements acquired using scintillation based detectors (thyroid probe and gamma camera) correlate better with the gold standard (i.e. the dose calibrator). Pearson correlations between the dose calibrator measurements and the GM counter, Ion chamber, thyroid probe, and gamma camera were found to be 0.88, 0.83, 0.98, 0.99, respectively. More acquisitions and analysis are planned to determine the precision of the systems, as well as optimal energy window settings. Conclusion: It is likely that current standard practice can be improved using scintillation crystal based detectors. Such systems are more sensitive, can integrate signal, and can use energy discrimination. Furthermore, phantoms can be built to integrate with probe and gamma camera systems that are robust and provide reproducibility. Future work will include expanded acquisition and analysis.
Early Interest in "Detection": "I would suggest that the best way to get reliable information in a short time would be to send from the States a man qualified to do the testing of the samples on the spot. This man should be officially a representative of the State Department, and his detecting devices, such as small portable Geiger Counters, could then go into Switzerland in the diplomatic pouch via air from Southern Italy. This man could then contact, through the Embassy, suitable people who could collect the water samples without arousing too much curiosity. A fishing trip in a boat would probably give the best disguise, as the fisherman could carry a water bottle in his lunch basket, and fill it after drinking the original contents. The water should be collected from the center of the river, to get the swiftest flowing water, so that the holdup could be minimized. In the lake, the water should be collected as near to the suspected site as possible, or as near to each of the inlet rivers as can be done. Speed in getting from the collection point to the counting room is of great importance, as you are, no doubt, aware." - Luis Alvarez to Major Furman, May 1944.
Determination of the proton energy spectrum in the inner van allen zone using data obtained from geiger counters on the explorer iv