Redesign of the Electronics and the Mechanical Sensor of the STS-1 Very Broadband Seismometer

Science.gov (United States)

Romanowicz, B.; van Zandt, T.; Friday, J.; Karavas, W.; Porritt, R.; Uhrhammer, R.; Wielandt, E.

2008-12-01

The STS-1 VBB, widely viewed as the finest VBB sensor in the world, is currently the principal broad-band seismometer used by the Global Seismographic Network (GSN), GEOSCOPE, and several other global or regional seismic networks. Its continued operation is critical to future, fundamental research in a number of important disciplines within seismology. These include modal studies of the earth, the determination of source processes of very large earthquakes, and tsunami warning. We have recently completed the development of a replacement electronics module for the Streckeisen STS-1 Very Broad-Band (VBB) seismometer. This module maintains the outstanding analog performance of the original sensor electronics, while providing a number of unique performance enhancements that will improve the operability of STS-1 sensors within a modern, digital seismic network. We describe the attributes of this new electronics module, which has now reached production stage. As a second step in this collaboration between the Berkeley Seismological Laboratory and Metrozet (Inc), we have started the development of a commercially-viable replacement to the aging, but state-of-the-art mechanical sensor. We discuss the goals of this new project. The design of the new sensor aims at maintaining many of the unique features that have made the original sensor the world's finest instrument for low frequency seismic recording. It will, however, implement a number of enhancements that promise to improve operating performance and ease-of-use. These include the use of capacitive position sensing to reduce high frequency self-noise, an increase in the upper corner frequency of the sensor, much tighter tolerance (sensor-to-sensor) in scalar response values, and a new, highly-integrated package for deploying the sensors as a standard triaxial set. Importantly, the replacement sensor development is driven by principles of "design-for manufacturing". As such, the new sensor will include a number of

Wireless passive radiation sensor

Science.gov (United States)

Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

2013-12-03

A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

A MODEL FOR PRODUCING STABLE, BROADBAND TERAHERTZ COHERENT SYNCHROTRON RADIATION IN STORAGE RINGS

International Nuclear Information System (INIS)

Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Martin, MichaelC.; Venturini, Marco

2003-01-01

We present a model for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use this model to optimize the performance of a source for CSR emission

Test on radiation-withstanding properties of sensors

International Nuclear Information System (INIS)

Yagi, Hideyuki; Kakuta, Tsunemi; Ara, Katsuyuki

1986-01-01

In order to use for the remote operation system or in-line measuring system in the facilities handling radioactive substances, the development of the sensors having strengthened radiation-withstanding performance has been advanced. As a part of it, efforts have been exerted to phenomenologically grasp the radiation effect on various sensors and their materials, and to acquire the basic data. Irradiation test was carried out on solid image pick-up elements, optical parts eddy current sensors, pressure sensitive rubber, photo-electric proximity sensors and others, and the knowledge on their deterioration was obtained. Besides, the sensors and video-cameras having improved radiation-withstanding performance were made for trial, and the performance was tested. The interim report on these test results is made. By a series of the irradiation tests reported here, the basic data required for giving the guideline to the development of radiation withstanding sensors were able to be obtained. But in the present irradiation test, the number of specimens was too small to assure the radiation withstanding performance. In order to improve further the radiation withstanding performance of these sensors, it is necessary to carry out the irradiation test on such elements as condensers, diodes and ICs to accumulate the basic data. (Kako, I.)

Characteristic evaluation of acoustic emission sensors

Energy Technology Data Exchange (ETDEWEB)

Jung, Hyun Kyu; Joo, Y. S.; Lee, N. H

2000-12-01

This report introduces the various kinds of Acoustic Emission(AE) sensors as well as the basic principle of AE sensors in order to select AE sensor suitably. The described sensors include : high sensitivity sensor, broadband sensor, underwater sensor, miniature sensor, directional sensor, integral pre-amplifier sensor. Sensor has two critical aspects of reliability and repeatability. For the high reliability, sensor has to be calibrated in accordance with ASTM standard E 1106 which explains to measure the characteristics of AE sensor accurately. For investigating the degradation of AE sensor under the severe environment for example the high radiation condition, It is important to perform the repeatability test which is described in detail in according to the ASTM standard E 976. Two kinds of AE sensor applications are also summarized.

Acoustic emission sensor radiation damage threshold experiment

International Nuclear Information System (INIS)

Beeson, K.M.; Pepper, C.E.

1994-01-01

Determination of the threshold for damage to acoustic emission sensors exposed to radiation is important in their application to leak detection in radioactive waste transport and storage. Proper response to system leaks is necessary to ensure the safe operation of these systems. A radiation impaired sensor could provide ''false negative or false positive'' indication of acoustic signals from leaks within the system. Research was carried out in the Radiochemical Technology Division at Oak Ridge National Laboratory to determine the beta/gamma radiation damage threshold for acoustic emission sensor systems. The individual system consisted of an acoustic sensor mounted with a two part epoxy onto a stainless steel waveguide. The systems were placed in an irradiation fixture and exposed to a Cobalt-60 source. After each irradiation, the sensors were recalibrated by Physical Acoustics Corporation. The results were compared to the initial calibrations performed prior to irradiation and a control group, not exposed to radiation, was used to validate the results. This experiment determines the radiation damage threshold of each acoustic sensor system and verifies its life expectancy, usefulness and reliability for many applications in radioactive environments

Radiation-activated sensor

International Nuclear Information System (INIS)

Nirschl, J.C.

1976-01-01

A sensing system is described for use in a remote location which detects electromagnetic radiation energy, the system being self-activating, turning itself automatically on and off, as a function of radiation intensity across the detector. In essence, when no radiation is present across the detector, the system will consume no power, the switches and MOSFET discriminator being essentially in an ''off'' position. Radiation across the detector provides a current to an input capacitance which when charged turns on the switch and the MOSFET discriminator. A switch driver produces an output pulse showing the presence of radiation; the system then shuts off awaiting the next radiation input. Since the sensor system uses virtually no power unless radiation is present, it is ideally suited for use in remote environments where battery power and size is a predominant consideration. 2 claims, 3 drawing figures

Review of high bandwidth fiber optics radiation sensors

International Nuclear Information System (INIS)

Lyons, P.B.

1985-01-01

This paper summarizes the use of fiber optics or guided optical systems for radiation sensors. It is limited a passive systems wherein electrical is not required at the sensor location. However, electrically powered light sources, receivers and/or recorders may still be required for detection and data storage in sensor system operation. This paper emphasizes sensor technologies that permit high bandwidth measurements of transient radiation levels, and will also discuss several low bandwidth applications. 60 refs

Feasibility Study on Fiber-optic Radiation Sensor for Remote Gamma-ray Spectroscopy

International Nuclear Information System (INIS)

Jeon, Hyesu; Jang, Kyoung Won; Shin, Sang Hun and others

2014-01-01

In this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors. As a result, the BGO was suitable for the sensing probe of fiber-optic radiation sensor due to its high scintillation output and exact photoelectric peak for the gamma-ray energy. The basic principle of radiation detection is to detect the signals caused by interactions between radiations and materials. There are various types of radiation detectors depending on types of radiation to be detected and physical quantities to be measured. As one of the radiation detectors, a fiber-optic radiation sensor using a scintillator and an optical fiber has two advantages such as no space restraint and remote sensing. Moreover, in nuclear environments, this kind of sensor has immunities for electromagnetic field, temperature, and pressure. Thus, the fiber-optic radiation sensor can be used in various fields including nondestructive inspection, radioactive waste management, nuclear safety, radiodiagnosis and radiation therapy. As a fundamental study of the fiber-optic radiation sensor for remote gamma-ray spectroscopy, in this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors

Recent results on CVD diamond radiation sensors

Science.gov (United States)

Weilhammer, P.; Adam, W.; Bauer, C.; Berdermann, E.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; v. d. Eijk, R.; van Eijk, B.; Fallou, A.; Fish, D.; Fried, M.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knopfle, K. T.; Krammer, M.; Manfredi, P. F.; Meier, D.; LeNormand; Pan, L. S.; Pernegger, H.; Pernicka, M.; Plano, R.; Re, V.; Riester, J. L.; Roe, S.; Roff; Rudge, A.; Schieber, M.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Turchetta, R.; RD 42 Collaboration

1998-02-01

CVD diamond radiation sensors are being developed for possible use in trackers in the LHC experiments. The diamond promises to be radiation hard well beyond particle fluences that can be tolerated by Si sensors. Recent results from the RD 42 collaboration on charge collection distance and on radiation hardness of CVD diamond samples will be reported. Measurements with diamond tracking devices, both strip detectors and pixel detectors, will be discussed. Results from beam tests using a diamond strip detector which was read out with fast, 25 ns shaping time, radiation-hard pipeline electronics will be presented.

Performance of semiconductor radiation sensors for simple and low-cost radiation detector

International Nuclear Information System (INIS)

Tanimura, Yoshihiko; Birumachi, Atsushi; Yoshida, Makoto; Watanabe, Tamaki

2008-01-01

In order to develop a simple but reliable radiation detector for the general public, photon detection performances of radiation sensors have been studied in photon calibration fields and by Monte Carlo simulations. A silicon p-i-n photodiode and a CdTe detector were selected for the low cost sensors. Their energy responses to ambient dose equivalent H * (10) were evaluated over the energy range from 60 keV to 2 MeV. The response of the CdTe decreases markedly with increasing photon energy. On the other hand, the photodiode has the advantage of almost flat response above 150 keV. The sensitivities of these sensors are 4 to 6 cpm for the natural radiation. Detection limits of the radiation level are low enough to know the extreme increase of radiation due to emergency situations of nuclear power plants, fuel treatment facilities and so on. (author)

Tailored long range forces on polarizable particles by collective scattering of broadband radiation

International Nuclear Information System (INIS)

Holzmann, D; Ritsch, H

2016-01-01

Collective coherent light scattering by polarizable particles creates surprisingly strong, long range inter-particle forces originating from interference of the light scattered by different particles. While for monochromatic laser beams this interaction decays with the inverse distance, we show here that in general the effective interaction range and geometry can be controlled by the illumination bandwidth and geometry. As generic example we study the modifications inter-particle forces within a 1D chain of atoms trapped in the field of a confined optical nanofiber mode. For two particles we find short range attraction as well as optical binding at multiple distances. The range of stable distances shrinks with increasing light bandwidth and for a very large bandwidth field as e.g. blackbody radiation. We find a strongly attractive potential up to a critical distance beyond which the force gets repulsive. Including multiple scattering can even lead to the appearance of a stable configuration at a large distance. Such broadband scattering forces should be observable contributions in ultra-cold atom interferometers or atomic clocks setups. They could be studied in detail in 1D geometries with ultra-cold atoms trapped along or within an optical nanofiber. Broadband radiation force interactions might also contribute in astrophysical scenarios as illuminated cold dust clouds. (paper)

Electromagnetic and nuclear radiation detector using micromechanical sensors

Science.gov (United States)

Thundat, Thomas G.; Warmack, Robert J.; Wachter, Eric A.

2000-01-01

Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.

Sensor-guided threat countermeasure system

Science.gov (United States)

Stuart, Brent C.; Hackel, Lloyd A.; Hermann, Mark R.; Armstrong, James P.

2012-12-25

A countermeasure system for use by a target to protect against an incoming sensor-guided threat. The system includes a laser system for producing a broadband beam and means for directing the broadband beam from the target to the threat. The countermeasure system comprises the steps of producing a broadband beam and directing the broad band beam from the target to blind or confuse the incoming sensor-guided threat.

Autonomous low-noise system for broadband measurements of the cosmic microwave background radiation

Science.gov (United States)

Dekoulis, George

2009-05-01

This paper describes the digital side implementation of a new suborbital experiment for the measurement of broadband radiation emissions of the Cosmic Microwave Background (CMB) anisotropy. The system has been used in campaign mode for initial mapping of the galactic radiation power received at a single frequency. The recorded galactic sky map images are subsequently being used to forecast the emitted radiation at neighboring frequencies. A planned second campaign will verify the prediction algorithms efficiency in an autonomous manner. The system has reached an advanced stage in terms of hardware and software combined operation and intelligence, where other Space Physics measurements are performed autonomously depending on the burst event under investigation. The system has been built in a modular manner to expedite hardware and software upgrades. Such an upgrade has recently occurred mainly to expand the frequency range of space observations.

Long Term Measurement of the Earth's Radiation Budget using a constellation of Broadband Radiometers hosted on Iridium NEXT

Science.gov (United States)

Gupta, Om Prakash; Thoma, Donald; Chaloner, Chris; Russell, Jacqueline; Simpson, Bill; Spilling, David; Morris, Nigel; Caldwell, Martin; Oneill, Alan

The WMO called for "bringing new missions to operational status" and that "ERB should be measured through a constellation of sensors". A unique opportu-nity exists to host a set of Earth Radiation Budget (ERB) sensors on the Iridium NEXT (NEXT) LEO constellation in a cost effective manner that can deliver these requirements. The NEXT constellation, with 66 interconnected satellites in 6 near polar orbiting planes, provides a unique platform for hosting a variety of Earth observation missions including ERB. Launches are planned to begin in 2014 through 2016. The ERB both drives and responds to global climate and monitoring it can provide much insight into the climate system and how it might be changing. A climate quality measurement of the ERB requires high absolute accuracy and excellent stability and a long-term (decades) data record in order to inform the debate about global warming. Measurement of the ERB in terms of the broadband reflected solar (0.3 to 4 µm) and emitted thermal (4 to 200 µm) components have been identified as high priority by the WMO for climate observations. High temporal resolution is the key advantage offered by the NEXT platform and can provide a great step forward in accurately monitoring the energy balance of the planet. The sensor we propose will consist of a broad band instrument and associated imager for scene identification and cloud classification. There is the chance to place two such sensors in each of six different orbital planes this will improve the product refresh time from currently 12 hours to 3 hours. The increased temporal resolution will allow direct measure-ment of the changes to the broadband radiances that result from rapidly varying components of the climate such as cloud and aerosol, and avoid the need of relying on narrow band sensors to infer such changes. Considering that the prediction of cloud response to climate change is still a major source of uncertainty; improved measurement of the cloud effect and

Air temperature sensors: dependence of radiative errors on sensor diameter in precision metrology and meteorology

Science.gov (United States)

de Podesta, Michael; Bell, Stephanie; Underwood, Robin

2018-04-01

In both meteorological and metrological applications, it is well known that air temperature sensors are susceptible to radiative errors. However, it is not widely known that the radiative error measured by an air temperature sensor in flowing air depends upon the sensor diameter, with smaller sensors reporting values closer to true air temperature. This is not a transient effect related to sensor heat capacity, but a fluid-dynamical effect arising from heat and mass flow in cylindrical geometries. This result has been known historically and is in meteorology text books. However, its significance does not appear to be widely appreciated and, as a consequence, air temperature can be—and probably is being—widely mis-estimated. In this paper, we first review prior descriptions of the ‘sensor size’ effect from the metrological and meteorological literature. We develop a heat transfer model to describe the process for cylindrical sensors, and evaluate the predicted temperature error for a range of sensor sizes and air speeds. We compare these predictions with published predictions and measurements. We report measurements demonstrating this effect in two laboratories at NPL in which the air flow and temperature are exceptionally closely controlled. The results are consistent with the heat-transfer model, and show that the air temperature error is proportional to the square root of the sensor diameter and that, even under good laboratory conditions, it can exceed 0.1 °C for a 6 mm diameter sensor. We then consider the implications of this result. In metrological applications, errors of the order of 0.1 °C are significant, representing limiting uncertainties in dimensional and mass measurements. In meteorological applications, radiative errors can easily be much larger. But in both cases, an understanding of the diameter dependence allows assessment and correction of the radiative error using a multi-sensor technique.

Radiation effects on active pixel sensors (APS)

International Nuclear Information System (INIS)

Cohen, M.; David, J.P.

1999-01-01

Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using 60 Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity

Radiation distribution sensor with optical fibers for high radiation fields

International Nuclear Information System (INIS)

Takada, Eiji; Kimura, Atsushi; Hosono, Yoneichi; Takahashi, Hiroyuki; Nakazawa, Masaharu

1999-01-01

Radiation distribution sensors with their feasibilities have been described in earlier works. However, due to large radiation induced transmission losses in optical fibers, especially in the visible wavelength region, it has been difficult to apply these techniques to high radiation fields. In this study, we proposed a new concept of optical fiber based radiation distribution measurements with near infrared (IR) emission. Near IR scintillators were attached to the ends of optical fibers, where the fibers were bundled and connected to an N-MOS line sensor or a cooled CCD camera. From the measurements of each area density, the radiation levels at the positions of the scintillators can be known. The linearity between the gamma dose rate at each scintillator and the registered counts has been examined. For correcting the radiation induced loss effects, we applied the Optical Time Domain Reflectometry technique to measure the loss distribution and from the results, a possibility for correction of the loss effect has been demonstrated. The applicable dose rate range was evaluated to be from 0.1 to 10 3 Gy/h. This system can be a promising tool as a flexible dose rate distribution monitor in radiation facilities like nuclear plants and accelerator facilities. (author)

Fluid dynamic analysis and experimental study of a low radiation error temperature sensor

Energy Technology Data Exchange (ETDEWEB)

Yang, Jie, E-mail: yangjie396768@163.com [Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing 210044 (China); School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Liu, Qingquan, E-mail: andyucd@163.com [Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing 210044 (China); Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology, Nanjing 210044 (China); Dai, Wei, E-mail: daiweiilove@163.com [Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing 210044 (China); School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044 (China); Ding, Renhui, E-mail: drhabcd@sina.com [Jiangsu Meteorological Observation Center, Nanjing 210008 (China)

2017-01-30

To improve the air temperature observation accuracy, a low radiation error temperature sensor is proposed. A Computational Fluid Dynamics (CFD) method is implemented to obtain radiation errors under various environmental conditions. The low radiation error temperature sensor, a naturally ventilated radiation shield, a thermometer screen and an aspirated temperature measurement platform are characterized in the same environment to conduct the intercomparison. The aspirated platform served as an air temperature reference. The mean radiation errors of the naturally ventilated radiation shield and the thermometer screen are 0.57 °C and 0.32 °C, respectively. In contrast, the mean radiation error of the low radiation error temperature sensor is 0.05 °C. The low radiation error temperature sensor proposed in this research may be helpful to provide a relatively accurate air temperature measurement result. - Highlights: • A CFD method is applied to obtain a quantitative solution of radiation error. • A temperature sensor is proposed to minimize radiation error. • The radiation error of the temperature sensor is on the order of 0.05 °C.

A broadband electromagnetic UT system

International Nuclear Information System (INIS)

Repplinger, W.; Salzburger, H.J.

1985-01-01

An ultrasonic testing system based on contactless electromagnetic acoustic (E.M.A.) transduction has been developed by which broadband ultrasonic pulses are excited. This system overcomes disadvantages of usual E.M.A. transducers with meanderlike coil configuration, namely the excitation of narrowband pulses and the symmetrical radiation pattern. By dividing up a meanderlike coil into single elements and a time-delayed firing of the elements, whereby the time delay is given by the distance of the elements and the phase velocity of the wave propagating along the surface, the ultrasonic pulse radiated in one preferred direction becomes broadband by constructive interference. The signals radiated in the opposite direction do no more interfere. Its amplitude is smaller than that of the other direction, so that the transducer becomes uni-directional. This technique can be applied for the excitation of all dispersionless waves (bulk waves and guided waves)

Ultra-Low Power Consuming Direct Radiation Sensors Based on Floating Gate Structures

Directory of Open Access Journals (Sweden)

Evgeny Pikhay

2017-07-01

Full Text Available In this paper, we report on ultra-low power consuming single poly floating gate direct radiation sensors. The developed devices are intended for total ionizing dose (TID measurements and fabricated in a standard CMOS process flow. Sensor design and operation is discussed in detail. Original array sensors were suggested and fabricated that allowed high statistical significance of the radiation measurements and radiation imaging functions. Single sensors and array sensors were analyzed in combination with the specially developed test structures. This allowed insight into the physics of sensor operations and exclusion of the phenomena related to material degradation under irradiation in the interpretation of the measurement results. Response of the developed sensors to various sources of ionizing radiation (Gamma, X-ray, UV, energetic ions was investigated. The optimal design of sensor for implementation in dosimetry systems was suggested. The roadmap for future improvement of sensor performance is suggested.

Radiation hardness of diamond and silicon sensors compared

CERN Document Server

de Boer, Wim; Furgeri, Alexander; Mueller, Steffen; Sander, Christian; Berdermann, Eleni; Pomorski, Michal; Huhtinen, Mika

2007-01-01

The radiation hardness of silicon charged particle sensors is compared with single crystal and polycrystalline diamond sensors, both experimentally and theoretically. It is shown that for Si- and C-sensors, the NIEL hypothesis, which states that the signal loss is proportional to the Non-Ionizing Energy Loss, is a good approximation to the present data. At incident proton and neutron energies well above 0.1 GeV the radiation damage is dominated by the inelastic cross section, while at non-relativistic energies the elastic cross section prevails. The smaller inelastic nucleon-Carbon cross section and the light nuclear fragments imply that at high energies diamond is an order of magnitude more radiation hard than silicon, while at energies below 0.1 GeV the difference becomes significantly smaller.

Fabrication of advanced military radiation detector sensor and performance evaluation

International Nuclear Information System (INIS)

Kang, Sin Yang

2010-02-01

Recently, our country is facing a continuous nuclear weapons threat. Therefore, we must have a high-level nuclear weapons protection system. The best protection against nuclear weapons is detecting their use to reduce casualties in our country to a minimum. That means, the development of a military radiation detector is a very important issue. The Korea army is using the 'PDR - 1K portable military radiation surveymeter' in NBC (Nuclear, Biological, Chemical warfare) operations. The PDR - 1K military detector can measure beta and gamma rays only but it cannot detect alpha particles. Because of its characteristics, the Korea army has weaknesses in tactical operations. The PDR - 1K sensor is based on a GM - tube sensor system. For the mechanical structure, detectors utilizing a GM-tube sensor do not work on a high - radiation battlefield and they do not carry out nuclide analysis for fixed electron signal output. In the meantime, the United States of America and Germany are using 'AN/PDR - 77' and 'SVG - 2' that were made from scintillator sensors. They have excellent physical qualities and radiation responses for military use. Also, nuclide analysis is available. Therefore, in this study we fabricated a military - grade scintillator radiation sensor that is able to detect alpha, beta, and gamma - rays to overcome PDR - 1K's weaknesses. Also, physical characteristics and radiation response evaluation for the fabricated sensors was carried out. The alpha - particle sensor and beta - ray sensor were fabricated using a ZnS(Ag) powder state scintillator, and a Saint - Gobain organic plastic scintillator BC-408 panel, respectively. The gamma ray sensor was manufactured using a 10 x 10 x 10 mm 3 CsI(Tl) inorganic scintillator crystal. A detailed explanation follows. The alpha particle sensor was fabricated by using air - brushing method to Zns(Ag) powder scintillator spreading. The ZnS(Ag) layer thickness was 35 μm (detection efficiency: 41%). This alpha - particle sensor

Applications of a nanocomposite-inspired in-situ broadband ultrasonic sensor to acousto-ultrasonics-based passive and active structural health monitoring.

Science.gov (United States)

Liu, Menglong; Zeng, Zhihui; Xu, Hao; Liao, Yaozhong; Zhou, Limin; Zhang, Zhong; Su, Zhongqing

2017-07-01

A novel nanocomposite-inspired in-situ broadband ultrasonic sensor previously developed, with carbon black as the nanofiller and polyvinylidene fluoride as the matrix, was networked for acousto-ultrasonic wave-based passive and active structural health monitoring (SHM). Being lightweight and small, this kind of sensor was proven to be capable of perceiving strain perturbation in virtue of the tunneling effect in the formed nanofiller conductive network when acousto-ultrasonic waves traverse the sensor. Proof-of-concept validation was implemented, to examine the sensor performance in responding to acousto-ultrasonic waves in a broad frequency regime: from acoustic emission (AE) of lower frequencies to guided ultrasonic waves (GUWs) of higher frequencies. Results have demonstrated the high fidelity, ultrafast response and high sensitivity of the sensor to acousto-ultrasonic waves up to 400kHz yet with an ultra-low magnitude (of the order of micro-strain). The sensor is proven to possess sensitivity and accuracy comparable with commercial piezoelectric ultrasonic transducers, whereas with greater flexibility in accommodating curved structural surfaces. Application paradigms of using the sensor for damage evaluation have spotlighted the capability of the sensor in compromising "sensing cost" with "sensing effectiveness" for passive AE- or active GUW-based SHM. Copyright © 2017 Elsevier B.V. All rights reserved.

Broadband Direct UVA irradiance measurement for clear skies evaluated using a smartphone

International Nuclear Information System (INIS)

Igoe, D.; Parisi, A.V.

2015-01-01

UVA wavelengths (320-400 nm) have been implicated in recent studies to contribute to melanoma induction and skin photo-aging in humans and damage to plants. The use of smartphones in UVA observations is a way to supplement measurements made by traditional radiometric and spectro-radiometric technology. Although the smartphone image sensor is not capable of determining broadband UVA irradiances, these can be reconstructed from narrowband irradiances, which the smartphone, with narrowband and neutral density filters, can quantify with discrepancies not exceeding 5 %. Three models that reconstruct direct broadband clear sky UVA were developed from narrowband irradiances derived from smartphone image sensor pixel data with coefficients of determination of between 0.97 and 0.99. Reasonable accuracy and precision in determining the direct broadband UVA was maintained for observations made with solar zenith angles as high as 70 deg. . The developed method has the potential to increase the uptake of the measurement of broadband UVA irradiances. (authors)

Conversion of broadband IR radiation and structural disorder in lithium niobate single crystals with low photorefractive effect

Science.gov (United States)

Litvinova, Man Nen; Syuy, Alexander V.; Krishtop, Victor V.; Pogodina, Veronika A.; Ponomarchuk, Yulia V.; Sidorov, Nikolay V.; Gabain, Aleksei A.; Palatnikov, Mikhail N.; Litvinov, Vladimir A.

2016-11-01

The conversion of broadband IR radiation when the noncritical phase matching condition is fulfilled in lithium niobate (LiNbO3) single crystals with stoichiometric (R = Li/Nb = 1) and congruent (R = 0.946) compositions, as well as in congruent single crystals doped with zinc has been investigated. It is shown that the spectrum parameters of converted radiation, such as the conversion efficiency, spectral width and position of maximum, depend on the ordering degree of structural units of the cation sublattice along the polar axis of crystal.

Development of Sensor Technology and Its Application for Nuclear Radiation Detection

International Nuclear Information System (INIS)

Hiskia

2007-01-01

Radiation is energy in the form of waves or moving subatomic particles. Radiation can be ionizing or nonionizing radiation, depending on its effect on atomic matter. Because radiation cannot be seen, felt, tasted, heard or smelled, even at lethal levels, radiations detection devices must be used to alert those exposed to radiation. The measurement of radioactivity in the environment is a regulatory requirement around sites where significant amounts of radioactive materials are used or stored. Recently, advent in microelectronics and material technology has enabled to produce small sensor or microsensor, sensitive, accurate, and integrated in a chip or substrate. Development of radiation sensor technology using thin/thick film and micromachining technique was described in this paper. Indonesian capabilities in radiation sensor research and development and opportunities for commercialization also given. (author)

The Development of Sensor Technology and Application to Detect Nuclear Radiation

International Nuclear Information System (INIS)

Hiskia

2007-01-01

Radiation is energy in the form of waves or moving subatomic particles. Radiation can be ionizing or non-ionizing radiation, depending on its effect on atomic matter. Because radiation cannot be seen, felt, tasted, heard or smelled, even at lethal levels, radiations detection devices must be used to alert those exposed to radiation. The measurement of radioactivity in the environment is a regulatory requirement around sites where significant amounts of radioactive materials are used or stored. Recently, advent in microelectronics and material technology has enabled to produce small sensor or microsensor, sensitive, accurate, and integrated in a chip or substrate. Development of radiation sensor technology using thin/thick film and micromachining technique was described in this paper. Indonesian capabilities in radiation sensor research and development and opportunities for commercialization also given. (author)

Multi-dimensional fiber-optic radiation sensor for ocular proton therapy dosimetry

International Nuclear Information System (INIS)

Jang, K.W.; Yoo, W.J.; Moon, J.; Han, K.T.; Park, B.G.; Shin, D.; Park, S-Y.; Lee, B.

2012-01-01

In this study, we fabricated a multi-dimensional fiber-optic radiation sensor, which consists of organic scintillators, plastic optical fibers and a water phantom with a polymethyl methacrylate structure for the ocular proton therapy dosimetry. For the purpose of sensor characterization, we measured the spread out Bragg-peak of 120 MeV proton beam using a one-dimensional sensor array, which has 30 fiber-optic radiation sensors with a 1.5 mm interval. A uniform region of spread out Bragg-peak using the one-dimensional fiber-optic radiation sensor was obtained from 20 to 25 mm depth of a phantom. In addition, the Bragg-peak of 109 MeV proton beam was measured at the depth of 11.5 mm of a phantom using a two-dimensional sensor array, which has 10×3 sensor array with a 0.5 mm interval.

Ways of providing radiation resistance of magnetic field semiconductor sensors

CERN Document Server

Bolshakova, I A; Holyaka, R; Matkovskii, A; Moroz, A

2001-01-01

Hall magnetic field sensors resistant to hard ionizing irradiation are being developed for operation under the radiation conditions of space and in charged particle accelerators. Radiation resistance of the sensors is first determined by the properties of semiconductor materials of sensitive elements; we have used microcrystals and thin layers of III-V semiconductors. Applying complex doping by rare-earth elements and isovalent impurities in certain proportions, we have obtained magnetic field sensors resistant to irradiation by fast neutrons and gamma-quanta. Tests of their radiation resistance were carried out at IBR-2 at the Joint Institute for Nuclear Research (Dubna). When exposed to neutrons with E=0.1-13 MeV and intensity of 10 sup 1 sup 0 n cm sup - sup 2 s sup - sup 1 , the main parameter of the sensors - their sensitivity to magnetic fields - changes by no more than 0.1% up to fluences of 10 sup 1 sup 4 n cm sup - sup 2. Further improvement of radiation resistance of sensor materials is expected by ...

Fabrication of advanced military radiation detector sensor and performance evaluation

Energy Technology Data Exchange (ETDEWEB)

Kang, Sin Yang

2010-02-15

Recently, our country is facing a continuous nuclear weapons threat. Therefore, we must have a high-level nuclear weapons protection system. The best protection against nuclear weapons is detecting their use to reduce casualties in our country to a minimum. That means, the development of a military radiation detector is a very important issue. The Korea army is using the 'PDR - 1K portable military radiation surveymeter' in NBC (Nuclear, Biological, Chemical warfare) operations. The PDR - 1K military detector can measure beta and gamma rays only but it cannot detect alpha particles. Because of its characteristics, the Korea army has weaknesses in tactical operations. The PDR - 1K sensor is based on a GM - tube sensor system. For the mechanical structure, detectors utilizing a GM-tube sensor do not work on a high - radiation battlefield and they do not carry out nuclide analysis for fixed electron signal output. In the meantime, the United States of America and Germany are using 'AN/PDR - 77' and 'SVG - 2' that were made from scintillator sensors. They have excellent physical qualities and radiation responses for military use. Also, nuclide analysis is available. Therefore, in this study we fabricated a military - grade scintillator radiation sensor that is able to detect alpha, beta, and gamma - rays to overcome PDR - 1K's weaknesses. Also, physical characteristics and radiation response evaluation for the fabricated sensors was carried out. The alpha - particle sensor and beta - ray sensor were fabricated using a ZnS(Ag) powder state scintillator, and a Saint - Gobain organic plastic scintillator BC-408 panel, respectively. The gamma ray sensor was manufactured using a 10 x 10 x 10 mm{sup 3} CsI(Tl) inorganic scintillator crystal. A detailed explanation follows. The alpha particle sensor was fabricated by using air - brushing method to Zns(Ag) powder scintillator spreading. The ZnS(Ag) layer thickness was 35 {mu}m (detection

Infrared response of YBa2Cu3O7-δ films to pulsed, broadband synchrotron radiation

International Nuclear Information System (INIS)

Carr, G.L.; Quijada, M.; Tanner, D.B.; Etemad, S.; DeRosa, F.; Venkatesan, T.; Dutta, B.; Hemmick, D.; Xi, X.

1990-01-01

We report studies of a thin high T c film operating as a fast bolometric detector of infrared radiation. The film has a response of infrared radiation. The film has a response of several mV when exposed to a 1 W, 1 ns duration broadband infrared pulse. The decay after the pulse was about 4 ns. The temperature dependence of the response accurately tracked dR/dT. A thermal model, in which the film's temperature varies relative to the substrate, provides a good description of the response. We find no evidence for other (non-bolometric) response mechanisms for temperatures near or well below T c . 13 refs., 4 figs

Field measurements of the global UV-B radiation: a comparison between a broad-band radiometer and a Brewer spectrophotometer

International Nuclear Information System (INIS)

Anav, A.; Moriconi, M.L.; Di Menno, M.; Giannoccolo, S.

1996-01-01

The spectral responsivity shape plays an important role in the prospect of a wide use of broad-band meters in the UV-B monitoring. As most UV-B broad-band meters have a responsivity approximating an erythemal action spectrum, a measurement campaign was planned to verify if such an instrument could be successfully used to measure the unfiltered global irradiance. A Yankee radiometer mod. UV-B 1 and a Brewer spectrophotometer, considered as a reference meter, were compared for this purpose. A short theoretical treatment of the Yankee radiometer response and some results of the comparison are shown. Only clear-sky days data are selected so that the UV-B radiation reaching the ground could be modelled as the sum of the direct and isotropic diffuse components. The comparison results show a good agreement between the two instruments and confirm the capability of a broad-band UV-B radiometer of correctly measuring the global irradiance

A non-invasive, quantitative study of broadband spectral responses in human visual cortex.

Directory of Open Access Journals (Sweden)

Eline R Kupers

Full Text Available Currently, non-invasive methods for studying the human brain do not routinely and reliably measure spike-rate-dependent signals, independent of responses such as hemodynamic coupling (fMRI and subthreshold neuronal synchrony (oscillations and event-related potentials. In contrast, invasive methods-microelectrode recordings and electrocorticography (ECoG-have recently measured broadband power elevation in field potentials (~50-200 Hz as a proxy for locally averaged spike rates. Here, we sought to detect and quantify stimulus-related broadband responses using magnetoencephalography (MEG. Extracranial measurements like MEG and EEG have multiple global noise sources and relatively low signal-to-noise ratios; moreover high frequency artifacts from eye movements can be confounded with stimulus design and mistaken for signals originating from brain activity. For these reasons, we developed an automated denoising technique that helps reveal the broadband signal of interest. Subjects viewed 12-Hz contrast-reversing patterns in the left, right, or bilateral visual field. Sensor time series were separated into evoked (12-Hz amplitude and broadband components (60-150 Hz. In all subjects, denoised broadband responses were reliably measured in sensors over occipital cortex, even in trials without microsaccades. The broadband pattern was stimulus-dependent, with greater power contralateral to the stimulus. Because we obtain reliable broadband estimates with short experiments (~20 minutes, and with sufficient signal-to-noise to distinguish responses to different stimuli, we conclude that MEG broadband signals, denoised with our method, offer a practical, non-invasive means for characterizing spike-rate-dependent neural activity for addressing scientific questions about human brain function.

A theoretical approach to photosynthetically active radiation silicon sensor

International Nuclear Information System (INIS)

Tamasi, M.J.L.; Martínez Bogado, M.G.

2013-01-01

This paper presents a theoretical approach for the development of low cost radiometers to measure photosynthetically active radiation (PAR). Two alternatives are considered: a) glass optical filters attached to a silicon sensor, and b) dielectric coating on a silicon sensor. The devices proposed are based on radiometers previously developed by the Argentine National Atomic Energy Commission. The objective of this work is to adapt these low cost radiometers to construct reliable instruments for measuring PAR. The transmittance of optical filters and sensor response have been analyzed for different dielectric materials, number of layers deposited, and incidence angles. Uncertainties in thickness of layer deposition were evaluated. - Highlights: • Design of radiometers to measure photosynthetically active radiation • The study has used a filter and a Si sensor to modify spectral response. • Dielectric multilayers on glass and silicon sensor • Spectral response related to different incidence angles, materials and spectra

Broadband 0.25-um Gallium Nitride (GaN) Power Amplifier Designs

Science.gov (United States)

2017-08-14

networking, and sensor systems of interest to Department of Defense applications, particularly for next-generation radar systems. Broadband, efficient, high...simulations of MMIC (3–6 GHz, 28 V/180 mA) 1.75-mm HEMT power amplifier ............................................... 13 Fig. 20 Simple schematic...design simple , a single 1.75-mm high-electron-mobility transistor (HEMT) was used for a preliminary ideal design of the broadband power amplifier

Miniaturized, low power FGMOSFET radiation sensor and wireless dosimeter system

KAUST Repository

Arsalan, Muhammad; Shamim, Atif; Tarr, Nicholas Garry; Roy, Langis

2013-01-01

A miniaturized floating gate (FG) MOSFET radiation sensor system is disclosed, The sensor preferably comprises a matched pair of sensor and reference FGMOSFETs wherein the sensor FGMOSFET has a larger area floating gate with an extension over a field oxide layer, for accumulation of charge and increased sensitivity. Elimination of a conventional control gate and injector gate reduces capacitance, and increases sensitivity, and allows for fabrication using standard low cost CMOS technology. A sensor system may be provided with integrated signal processing electronics, for monitoring a change in differential channel current I.sub.D, indicative of radiation dose, and an integrated negative bias generator for automatic pre-charging from a low voltage power source. Optionally, the system may be coupled to a wireless transmitter. A compact wireless sensor System on Package solution is presented, suitable for dosimetry for radiotherapy or other biomedical applications.

Miniaturized, low power FGMOSFET radiation sensor and wireless dosimeter system

KAUST Repository

Arsalan, Muhammad

2013-08-27

A miniaturized floating gate (FG) MOSFET radiation sensor system is disclosed, The sensor preferably comprises a matched pair of sensor and reference FGMOSFETs wherein the sensor FGMOSFET has a larger area floating gate with an extension over a field oxide layer, for accumulation of charge and increased sensitivity. Elimination of a conventional control gate and injector gate reduces capacitance, and increases sensitivity, and allows for fabrication using standard low cost CMOS technology. A sensor system may be provided with integrated signal processing electronics, for monitoring a change in differential channel current I.sub.D, indicative of radiation dose, and an integrated negative bias generator for automatic pre-charging from a low voltage power source. Optionally, the system may be coupled to a wireless transmitter. A compact wireless sensor System on Package solution is presented, suitable for dosimetry for radiotherapy or other biomedical applications.

Optical Fibre Temperature Sensor Based On A Blackbody Radiation

Science.gov (United States)

Hypszer, Ryszard; Plucinski, Jerzy; Wierzba, Henryk J.

1990-01-01

The principle of operation of the fibre optical temperature sensor based on a blackbody radiation and its construction model is given in the paper. A quartz rod of 0.6 mm diameter and 20 cm length with a blackbody cavity at the one end was used to construct the sensor. The cavity was made by vacuum evaporation of a chromium layer and a silicone monooxide layer was used as a protection. Infrared radiation is transmitted by the fibre optic to the detection circuit. This sensor enables temperature measurement from 400 to 1200°C. The range of measurement is determined by the detection sensitivity and by rod softening. The resolution is of the order of 10-2°C. The sensor calibration was done by using PtRh1O-Pt thermocouple.

A sensor element for direct radiation measurement

Energy Technology Data Exchange (ETDEWEB)

Bajons, P.; Wernhart, U.; Zeiler, H. [University of Vienna (Austria). Institut of Material Physics

1998-08-01

A combination of a photodiode with a nonimaging light concentrator is developed to perform measurements of the direct solar radiation component. A prototype composed of low price elements is taken as a starting point to discuss the problems which must be faced when calibrating such sensors. By this the influence of the angle of incidence and spectral distribution (caused by different air mass or varying degree of clearness) of the incident radiation on the behavior of the system is studied. The readings are compared to the calculated (global minus diffuse) readings obtained from two standard star pyranometers. Finally the possibilities for increasing the accuracy of the sensor element and for applying the device are discussed. (author)

Review of the development of diamond radiation sensors

CERN Document Server

Adam, W; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zöller, M

1999-01-01

Diamond radiation sensors produced by chemical vapour deposition are studied for the application as tracking detectors in high luminosity experiments. Sensors with a charge collection distance up to 250 mu m have been manufactured. Their radiation hardness has been studied with pions, proton and neutrons up to fluences of 1.9*10/sup 15/ pi cm/sup -2/, 5*10/sup 19/ p cm/sup -2/ and 1.35*10/sup 15/ n cm/sup -2 /, respectively. Diamond micro-strip detectors with 50 mu m pitch have been exposed in a high-energy test beam in order to investigate their charge collection properties. The measured spatial resolution using a centre-of-gravity position finding algorithm corresponds to the digital resolution for this strip pitch. First results from a strip tracker with a 2*4 cm/sup 2/ surface area are reported as well as the performance of a diamond tracker read out by radiation-hard electronics with 25 ns shaping time. Diamond pixel sensors have been prepared to match the geometries of the recently available read-out ch...

Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

Science.gov (United States)

Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

2005-06-01

For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

Science.gov (United States)

Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

2017-08-01

Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

Stabilized platform for tethered balloon soundings of broadband long- and short-wave radiation

International Nuclear Information System (INIS)

Alzheimer, J.M.; Anderson, G.A.; Whiteman, C.D.

1993-01-01

Changes in the composition of trace gases in the earth's atmosphere have been reported by many observers, and a general concern has been expressed regarding possible changes to the earth's climate that may be caused by radiatively active gases introduced into the earth's atmosphere by man's activities. Radiatively active trace gases produce temperature changes in the earth's atmosphere through changes in radiative flux divergence. Our knowledge of and means of measuring radiative flux divergence is very limited. A few observations of vertical radiative flux divergences have been reported from aircraft from radiometersondes from towers and from large tethered balloons. These measurement techniques suffers from one or more drawbacks, including shallow sounding depths (towers), high cost (aircraft), complicated logistics (large tethered balloons), and limitation to nighttime hours (radiometersondes). Changes in radiative flux divergence caused by anthropogenic trace gases are expected to be quite small, and will be difficult to measure with existing broadband radiative flux instruments. The emphasis of present research in global climate change is thus being focused on improving radiative transfer algorithms in global climate models. The radiative parameterizations in these models are at an early stage of development and information is needed regarding their performance, especially in cloudy conditions. The impetus for the research reported in this paper is the need for a device that can supplement existing means of measuring vertical profiles of long- and short-wave irradiance and radiative flux divergence. We have designed a small tethered-balloon-based system that can make radiometric soundings through the atmospheric boundary layer. This paper discusses the concept, the design considerations, and the design and construction of this sounding system. The performance of the system will be tested in a series of balloon flights scheduled for the fall and winter of 1992

A single-layer flat-coil-oscillator (SFCO)-based super-broadband position sensor for nano-scale-resolution seismometry

Energy Technology Data Exchange (ETDEWEB)

Gevorgyan, Samvel [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, Yerevan 0025 (Armenia); Institute for Physical Researches, National Academy of Sciences, Gitavan IFI, 0203 Ashtarak-2 (Armenia)], E-mail: gevs_sam@web.am; Gevorgyan, Vardan [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, Yerevan 0025 (Armenia); Institute for Physical Researches, National Academy of Sciences, Gitavan IFI, 0203 Ashtarak-2 (Armenia); International Scientific-Educational Center, National Academy of Sciences, 24-D Marshal Baghramyan av., Yerevan 0019 (Armenia); Karapetyan, Gagik [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, Yerevan 0025 (Armenia); Institute for Physical Researches, National Academy of Sciences, Gitavan IFI, 0203 Ashtarak-2 (Armenia)

2008-05-15

A new class super-broadband, nano-scale-resolution position sensor is tested. It is used as an additional sensor in seismograph. It enables to extend the band and enhance the sensitivity of the available technique by at least an order of magnitude. It allows transferring of mechanical vibrations of constructions and buildings, with amplitudes over 1 nm, into detectable signal in a frequency range starting practically from quasi-static movements. It is based on detection of position changes of a vibrating normal-metallic plate placed near the flat coil-being used as a pick-up in a stable tunnel diode oscillator. Frequency of the oscillator is used as a detecting parameter, and the measuring effect is determined by a distortion of the MHz-range testing field configuration near a coil by a vibrating plate, leading to magnetic inductance changes of the coil, with a resolution {approx}10 pH. This results in changes of oscillator frequency. We discuss test data of such a position sensor, installed in a Russian SM-3 seismometer, as an additional pick-up component, showing its advantages compared to traditional techniques. We also discuss the future of such a novel sensor involving substitution of a metallic coil by a superconductive one and replacement of a tunnel diode by an S/I/S hetero-structure-as much less-powered active element in the oscillator, compared to tunnel diode. These may strongly improve the stability of oscillators, and therefore enhance the resolution of seismic techniques.

Classification of Reactor Facility Operational State Using SPRT Methods with Radiation Sensor Networks

Energy Technology Data Exchange (ETDEWEB)

Ramirez Aviles, Camila A. [ORNL; Rao, Nageswara S. [ORNL

2018-01-01

We consider the problem of inferring the operational state of a reactor facility by using measurements from a radiation sensor network, which is deployed around the facility’s ventilation stack. The radiation emissions from the stack decay with distance, and the corresponding measurements are inherently random with parameters determined by radiation intensity levels at the sensor locations. We fuse measurements from network sensors to estimate the intensity at the stack, and use this estimate in a one-sided Sequential Probability Ratio Test (SPRT) to infer the on/off state of the reactor facility. We demonstrate the superior performance of this method over conventional majority vote fusers and individual sensors using (i) test measurements from a network of NaI sensors, and (ii) emulated measurements using radioactive effluents collected at a reactor facility stack. We analytically quantify the performance improvements of individual sensors and their networks with adaptive thresholds over those with fixed ones, by using the packing number of the radiation intensity space.

Development of radiation hardened pixel sensors for charged particle detection

CERN Document Server

Koziel, Michal

2014-01-01

CMOS Pixel Sensors are being developed since a few years to equip vertex detectors for future high-energy physics experiments with the crucial advantages of a low material budget and low production costs. The features simultaneously required are a short readout time, high granularity and high tolerance to radiation. This thesis mainly focuses on the radiation tolerance studies. To achieve the targeted readout time (tens of microseconds), the sensor pixel readout was organized in parallel columns restricting in addition the readout to pixels that had collected the signal charge. The pixels became then more complex, and consequently more sensitive to radiation. Different in-pixel architectures were studied and it was concluded that the tolerance to ionizing radiation was limited to 300 krad with the 0.35- m fabrication process currently used, while the targeted value was several Mrad. Improving this situation calls for implementation of the sensors in processes with a smaller feature size which naturally imp...

Fabrication and a Study on the Tapered Scintillator Radiation Sensors

International Nuclear Information System (INIS)

Kim, Gye Hong

2003-02-01

Optical fibers have been investigated for their uses as sensor materials in various nuclear applications. Comprehensive overviews of their potential usages in nuclear environments can be found in the literatures. Optical fibers with doped scintillating elements in the core have drawn special interests as nuclear radiation detectors. The two important functions of a scintillating optical fiber, as a radiation detector, are scintillator (light emitter) and light transmitter. When radiation interacts with the core material, scintillation occurs and resultant lights are transmitted through the fiber to an opto-electronic device such as a photomultiplier tube. Optical fiber sensors have several advantages as compared to other sensors of conventional material. Since they do not require electric power in the sensor part, they are less susceptible to trouble in harsh environments such as underground or underwater. At relatively low cost a multi-point distributed radiation monitoring system could be made using the fiber sensors. Furthermore, unlike the conventional scintillating counters they are not influenced by any magnetic field surrounding them. This study has been conducted to investigate the feasibility of using scintillating optical fibers for the detection of gamma rays emitted by 137 Cs. Several types of gamma-ray sensors have been constructed by packing different numbers of fibers into aluminum tubes, and tested to detect the 137 Cs gamma ray. During the study it has been found that a tapered fibers might be more efficient to collect the lights produced inside the sensor and transfer them into the transmitting fiber. In order to investigate the effectiveness of the tapered fiber, tapered plastic scintillators, composed of polystyrene with minute amount of dPOPOP and PPO or bPBD, have been fabricated and tested for the detection of gamma rays from 1.0, 1.5, 3.0 and 5.0 μCi 137 Cs sources. The pulse height spectra and the relationship between the radioactivity and

Radiation detection and situation management by distributed sensor networks

International Nuclear Information System (INIS)

Jan, Frigo; Mielke, Angela; Cai, D. Michael

2009-01-01

Detection of radioactive materials in an urban environment usually requires large, portal-monitor-style radiation detectors. However, this may not be a practical solution in many transport scenarios. Alternatively, a distributed sensor network (DSN) could complement portal-style detection of radiological materials through the implementation of arrays of low cost, small heterogeneous sensors with the ability to detect the presence of radioactive materials in a moving vehicle over a specific region. In this paper, we report on the use of a heterogeneous, wireless, distributed sensor network for traffic monitoring in a field demonstration. Through wireless communications, the energy spectra from different radiation detectors are combined to improve the detection confidence. In addition, the DSN exploits other sensor technologies and algorithms to provide additional information about the vehicle, such as its speed, location, class (e.g. car, truck), and license plate number. The sensors are in-situ and data is processed in real-time at each node. Relevant information from each node is sent to a base station computer which is used to assess the movement of radioactive materials

CMOS front-end electronics for radiation sensors

CERN Document Server

AUTHOR|(CDS)2071026

2015-01-01

This book offers a comprehensive treatment of front-end electronics for radiation detection. It discusses the fundamental principles of signal processing for radiation detectors and describes circuits at the level of functional building blocks, omitting transistor-level implementation. It also covers important system-level topics commonly found in the world of front-end electronics for radiation sensors. The book develops the topics in detail, with a constant focus on practical problems. It also provides real implementation examples that offer insights and stimuli for more experienced engineers already working in the field.

Broadband electrical impedance matching for piezoelectric ultrasound transducers.

Science.gov (United States)

Huang, Haiying; Paramo, Daniel

2011-12-01

This paper presents a systematic method for designing broadband electrical impedance matching networks for piezoelectric ultrasound transducers. The design process involves three steps: 1) determine the equivalent circuit of the unmatched piezoelectric transducer based on its measured admittance; 2) design a set of impedance matching networks using a computerized Smith chart; and 3) establish the simulation model of the matched transducer to evaluate the gain and bandwidth of the impedance matching networks. The effectiveness of the presented approach is demonstrated through the design, implementation, and characterization of impedance matching networks for a broadband acoustic emission sensor. The impedance matching network improved the power of the acquired signal by 9 times.

A review of nanostructured based radiation sensors for neutron

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Pervaiz; Mohamed, Norani Muti; Burhanudin, Zainal Arif [Center of Excellence in Nanotechnology Department of Fundamental and Applied Sciences, Department of Electrical and Electronic Engineering Universiti Teknologi PETRONAS (Malaysia)

2012-09-26

Currently radiation sensors with various mechanisms such as radio thermo luminescence, radiographic and radiochromic film, semiconductor and ionization have been used for the detection of nuclear radiation. Sensitivity, handling procedure, heating condition, energy response, nonlinearity, polarization, non-uniform electric field, high bias voltage and spatial resolution due to large physical size are some of the key issues faced by these sensors. Due to the excellent electrical and mechanical properties, nanostructured materials such as carbon nanotubes (CNTs) have been researched as sensing elements in the sensors to overcome the mentioned problems. However CNTs are found to pose different problems, arising from the uncontrolled helicity and small cross-sectional area. Therefore, alternative sensing elements are still been sought after and the possibility of using boron nitride nanotubes for sensing neutron is considered in this review.

Broadband Access

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Broadband Access. Worldwide market for broadband access $30 Billion! Over 200 million broadband subscribers worldwide! Various Competing Broadband access. Digital Subscriber line; Wireless; Optical Fiber.

­The Carnegie Quick Deploy Box (QDB) for use with broadband and intermediate period sensors

Science.gov (United States)

Wagner, L. S.; Roman, D.; Bartholomew, T.; Golden, S.; Schleigh, B.

2017-12-01

Recent data processing advances have increased the call for dense recordings of teleseismic data. However, traditional broadband field installations typically comprise 1) a sensor vault 2) a field box to hold the recording and power systems, and 3) a solar panel mount. The construction of these installations is time consuming and requires bulky construction materials, limiting the number of stations that can be installed from a single vehicle without repeated trips to a storage facility. Depending on the deployment location, watertight containers for both vault and field box can be difficult to find, resulting in a loss of data due to flooding. Recent technological improvements have made possible the direct burial of sensors (no vault required) and a reduction in the size of the solar panels needed to run a station. With support from the Brinson Foundation, we take advantage of these advances to create a field box/shipping container that will greatly simplify these types of seismic deployments. The goal of the Carnegie Quick Deploy Box (QDB) is to have everything needed for an intermediate period station install (except battery and shovel) contained in a single box for shipment, and to be able to leave everything (except the shovel) in that box when the station is deployed. The box is small enough ( 13"x13"x21") and lightweight enough (< 35 lbs) to be checked as airline luggage. The solar panel mount can be attached securely to the top of the box, but it can also be pole mounted with U-bolts or hose clamps. The sensor can be direct-buried. The sensor cable and solar panel cable plug into watertight bulkhead-fitted plugs on the outside of the box that are in turn plugged into the digitizer and power regulator inside the box. Our prototype boxes (Pelican Cases) have proved watertight when submerged for days. This equipment has been tested in Alaska in winter and Nicaragua in summer without failure due to flooding or power. The cost for parts for a single box (not

Radiation tolerant fiber optic humidity sensors for High Energy Physics applications

CERN Document Server

Berruti, Gaia Maria; Cusano, Andrea

This work is devoted to the development of fiber optic humidity sensors to be applied in high-energy physics applications and in particular in experiments currently running at CERN. The high radiation level resulting from the operation of the accelerator at full luminosity can cause serious performance deterioration of the silicon sensors which are responsible for the particle tracking. To increase their lifetime, the sensors must be kept cold at temperatures below 0 C. At such low temperatures, any condensation risk has to be prevented and a precise thermal and hygrometric control of the air filling and surrounding the tracker detector cold volumes is mandatory. The technologies proposed at CERN for relative humidity monitoring are mainly based on capacitive sensing elements which are not designed with radiation resistance characteristic. In this scenario, fiber optic sensors seem to be perfectly suitable. Indeed, the fiber itself, if properly selected, can tolerate a very high level of radiation, optical fi...

Review of the development of diamond radiation sensors

International Nuclear Information System (INIS)

Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.

1999-01-01

Diamond radiation sensors produced by chemical vapour deposition are studied for the application as tracking detectors in high luminosity experiments. Sensors with a charge collection distance up to 250 μm have been manufactured. Their radiation hardness has been studied with pions, proton and neutrons up to fluences of 1.9x10 15 π cm -2 , 5x10 15 p cm -2 and 1.35x10 15 n cm -2 , respectively. Diamond micro-strip detectors with 50 μm pitch have been exposed in a high-energy test beam in order to investigate their charge collection properties. The measured spatial resolution using a centre-of-gravity position finding algorithm corresponds to the digital resolution for this strip pitch. First results from a strip tracker with a 2x4 cm 2 surface area are reported as well as the performance of a diamond tracker read out by radiation-hard electronics with 25 ns shaping time. Diamond pixel sensors have been prepared to match the geometries of the recently available read-out chip prototypes for ATLAS and CMS. Beam test results are shown from a diamond detector bump-bonded to an ATLAS prototype read-out. They demonstrate a 98% bump-bonding efficiency and a digital resolution in both dimensions. (author)

Review of the development of diamond radiation sensors

Science.gov (United States)

Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knöpfle, K. T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P. F.; Manfredotti, C.; Marshall, R. D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L. S.; Palmieri, V. G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.; RD42 Collaboration

1999-09-01

Diamond radiation sensors produced by chemical vapour deposition are studied for the application as tracking detectors in high luminosity experiments. Sensors with a charge collection distance up to 250 μm have been manufactured. Their radiation hardness has been studied with pions, proton and neutrons up to fluences of 1.9×10 15 π cm -2, 5×10 15 p cm -2 and 1.35×10 15 n cm -2, respectively. Diamond micro-strip detectors with 50 μm pitch have been exposed in a high-energy test beam in order to investigate their charge collection properties. The measured spatial resolution using a centre-of-gravity position finding algorithm corresponds to the digital resolution for this strip pitch. First results from a strip tracker with a 2×4 cm 2 surface area are reported as well as the performance of a diamond tracker read out by radiation-hard electronics with 25 ns shaping time. Diamond pixel sensors have been prepared to match the geometries of the recently available read-out chip prototypes for ATLAS and CMS. Beam test results are shown from a diamond detector bump-bonded to an ATLAS prototype read-out. They demonstrate a 98% bump-bonding efficiency and a digital resolution in both dimensions.

Comparison of VP broadband tiltmeter and VS vertical pendulum tiltmeter

Directory of Open Access Journals (Sweden)

Wugang Ma

2015-05-01

Full Text Available Vertical pendulum (VP tiltmeter is a kind of earthquake precursor observation equipment, which is used to record the interaction force associated with astronomical tidal tilts caused. Currently, VP broadband tiltmeter and vertical sensor (VS vertical pendulum tiltmeter are primarily used. In this paper, we compare the two different instruments by using four aspects—mechanical structure, circuitry, zeroing, and bandwidth—based on their working principles and applications. We conclude that VP broadband tiltmeter is more superior compared with VS vertical pendulum tiltmeter because of its higher bandwidth and degree of automation.

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

Energy Technology Data Exchange (ETDEWEB)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

2016-10-15

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

International Nuclear Information System (INIS)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

2016-01-01

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

Wavelength interrogation of fiber Bragg grating sensors using tapered hollow Bragg waveguides.

Science.gov (United States)

Potts, C; Allen, T W; Azar, A; Melnyk, A; Dennison, C R; DeCorby, R G

2014-10-15

We describe an integrated system for wavelength interrogation, which uses tapered hollow Bragg waveguides coupled to an image sensor. Spectral shifts are extracted from the wavelength dependence of the light radiated at mode cutoff. Wavelength shifts as small as ~10  pm were resolved by employing a simple peak detection algorithm. Si/SiO₂-based cladding mirrors enable a potential operational range of several hundred nanometers in the 1550 nm wavelength region for a taper length of ~1  mm. Interrogation of a strain-tuned grating was accomplished using a broadband amplified spontaneous emission (ASE) source, and potential for single-chip interrogation of multiplexed sensor arrays is demonstrated.

Optical fiber radiation sensors: first in vivo measurements during orbital irradiation

International Nuclear Information System (INIS)

Gripp, S.; Bannach, B.; Muskalla, K.; Haesing, F.; Bueker, H.; Schmitt, G.

1995-01-01

Purpose: To investigate the applicability of doped optical fiber radiation sensors in clinical dosimetry. Methods: Ionizing radiation causes a dose depending discoloring in silica. When proper impurities (doping agents) are added, the radiation sensitivity may be increased to a range suited for clinical dosimetry. We performed in-vivo-measurements using a lead doped silica fiber (d TM ) in comparison to thermoluminescence detectors (TLDs). Results: The scattered radiation is easily detected with this sensor fiber. In contrast to TLDs the dose and doserate values are obtained immediately and setup errors can be recognized before irradiation is completed. The SD clearly depends on setup modifications due to the extent of disease. Other doping agents (GeP) provide better tissue equivalence and less energy dependence. Conclusions: Optical fibers are suitable for in vivo dosimetry purposes. Fiber sensors provide real time dose values, and the readout procedure is much easier compared to TLDs. These features may gain significance in quality assurance, conformal therapy, and intraoperative radiotherapy (IORT)

Applications of Elpasolites as a Multimode Radiation Sensor

Science.gov (United States)

Guckes, Amber

This study consists of both computational and experimental investigations. The computational results enabled detector design selections and confirmed experimental results. The experimental results determined that the CLYC scintillation detector can be applied as a functional and field-deployable multimode radiation sensor. The computational study utilized MCNP6 code to investigate the response of CLYC to various incident radiations and to determine the feasibility of its application as a handheld multimode sensor and as a single-scintillator collimated directional detection system. These simulations include: • Characterization of the response of the CLYC scintillator to gamma-rays and neutrons; • Study of the isotopic enrichment of 7Li versus 6Li in the CLYC for optimal detection of both thermal neutrons and fast neutrons; • Analysis of collimator designs to determine the optimal collimator for the single CLYC sensor directional detection system to assay gamma rays and neutrons; Simulations of a handheld CLYC multimode sensor and a single CLYC scintillator collimated directional detection system with the optimized collimator to determine the feasibility of detecting nuclear materials that could be encountered during field operations. These nuclear materials include depleted uranium, natural uranium, low-enriched uranium, highly-enriched uranium, reactor-grade plutonium, and weapons-grade plutonium. The experimental study includes the design, construction, and testing of both a handheld CLYC multimode sensor and a single CLYC scintillator collimated directional detection system. Both were designed in the Inventor CAD software and based on results of the computational study to optimize its performance. The handheld CLYC multimode sensor is modular, scalable, low?power, and optimized for high count rates. Commercial?off?the?shelf components were used where possible in order to optimize size, increase robustness, and minimize cost. The handheld CLYC multimode

3D radiation sensors with three dimensional electrodes

CERN Document Server

Da Via, Cinzia; Parker, Sherwood

2018-01-01

This book covers the technical properties, fabrication details, measurement results and applications of three-dimensional silicon radiation sensors. Such devices are currently used in the ATLAS experiment at the European Centre for Particle Physics (CERN) for particle tracking in high energy physics. They are the radiation hardest devices ever fabricated. They have applications in neutron detection, medical dosimetry and space. Written by the leading names in this field, the book explains to non-experts the essential features of silicon particle detectors, interactions of radiation with matter, radiation damage effects, and micro-fabrication. It also provides an historical view of the above.

Passive radiation detection using optically active CMOS sensors

Science.gov (United States)

Dosiek, Luke; Schalk, Patrick D.

2013-05-01

Recently, there have been a number of small-scale and hobbyist successes in employing commodity CMOS-based camera sensors for radiation detection. For example, several smartphone applications initially developed for use in areas near the Fukushima nuclear disaster are capable of detecting radiation using a cell phone camera, provided opaque tape is placed over the lens. In all current useful implementations, it is required that the sensor not be exposed to visible light. We seek to build a system that does not have this restriction. While building such a system would require sophisticated signal processing, it would nevertheless provide great benefits. In addition to fulfilling their primary function of image capture, cameras would also be able to detect unknown radiation sources even when the danger is considered to be low or non-existent. By experimentally profiling the image artifacts generated by gamma ray and β particle impacts, algorithms are developed to identify the unique features of radiation exposure, while discarding optical interaction and thermal noise effects. Preliminary results focus on achieving this goal in a laboratory setting, without regard to integration time or computational complexity. However, future work will seek to address these additional issues.

Review of the development of diamond radiation sensors

Energy Technology Data Exchange (ETDEWEB)

Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J. E-mail: josel.hrubec@cern.ch; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M

1999-09-11

Diamond radiation sensors produced by chemical vapour deposition are studied for the application as tracking detectors in high luminosity experiments. Sensors with a charge collection distance up to 250 {mu}m have been manufactured. Their radiation hardness has been studied with pions, proton and neutrons up to fluences of 1.9x10{sup 15} {pi} cm{sup -2}, 5x10{sup 15} p cm{sup -2} and 1.35x10{sup 15} n cm{sup -2}, respectively. Diamond micro-strip detectors with 50 {mu}m pitch have been exposed in a high-energy test beam in order to investigate their charge collection properties. The measured spatial resolution using a centre-of-gravity position finding algorithm corresponds to the digital resolution for this strip pitch. First results from a strip tracker with a 2x4 cm{sup 2} surface area are reported as well as the performance of a diamond tracker read out by radiation-hard electronics with 25 ns shaping time. Diamond pixel sensors have been prepared to match the geometries of the recently available read-out chip prototypes for ATLAS and CMS. Beam test results are shown from a diamond detector bump-bonded to an ATLAS prototype read-out. They demonstrate a 98% bump-bonding efficiency and a digital resolution in both dimensions. (author)

Biological Sensors for Solar Ultraviolet Radiation

Directory of Open Access Journals (Sweden)

André P. Schuch

2011-04-01

Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

Small Pitch Transition-Edge Sensors with Broadband High Spectral Resolution for Solar Physics

Science.gov (United States)

Smith, S. J.; Adams, J. S.; Eckart, M. E.; Smith, Adams; Bailey, C. N.; Bandler, S. R.; Chevenak, J. A.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.;

The wireless sensor network monitoring system for regional environmental nuclear radiation

International Nuclear Information System (INIS)

Liu Chong; Liu Dao; Wang Yaojun; Xie Yuxi; Song Lingling

2012-01-01

The wireless sensor network (WSN) technology has been utilized to design a new regional environmental radiation monitoring system based on the wireless sensor networks to meet the special requirements of monitoring the nuclear radiation in certain regions, and realize the wireless transmission of measurement data, information processing and integrated measurement of the nuclear radiation and the corresponding environmental parameters in real time. The system can be applied to the wireless monitoring of nuclear radiation dose in the nuclear radiation environment. The measured data and the distribution of radiation dose can be vividly displayed on the graphical interface in the host computer. The system has functioned with the wireless transmission and control, the data storage, the historical data inquiry, the node remote control. The experimental results show that the system has the advantages of low power consumption, stable performance, network flexibility, range of measurement and so on. (authors)

Conversion of broadband thermal radiation in lithium niobate crystals of various compositions

Science.gov (United States)

Syuy, A. V.; Litvinova, M. N.; Goncharova, P. S.; Sidorov, N. V.; Palatnikov, M. N.; Krishtop, V. V.; Likhtin, V. V.

2013-05-01

The conversion of the broadband thermal radiation in stoichiometric ( R = 1) lithium niobate single crystals that are grown from melt with 58.6 mol % of LiO2, congruent ( R = Li/Nb = 0.946) melt with the K2O flux admixture (4.5 and 6.0 wt %), and congruent melt and in congruent single crystals doped with the Zn2+, Gd3+, and Er3+ cations is studied. It is demonstrated that the conversion efficiency of the stoichiometric crystal that is grown from the melt with 58.6 mol % of LiO2 is less than the conversion efficiency of congruent crystal. In addition, the stoichiometric and almost stoichiometric crystals and the doped congruent crystals exhibit the blue shift of the peak conversion intensity in comparison with a nominally pure congruent crystal. For the congruent crystals, the conversion intensities peak at 520 and 495 nm, respectively.

Shield or not to Shield: Effects of Solar Radiation on Water Temperature Sensor Accuracy

Directory of Open Access Journals (Sweden)

Robert L. Wilby

2013-10-01

Full Text Available Temperature sensors are potentially susceptible to errors due to heating by solar radiation. Although this is well known for air temperature (Ta, significance to continuous water temperature (Tw monitoring is relatively untested. This paper assesses radiative errors by comparing measurements of exposed and shielded Tinytag sensors under indirect and direct solar radiation, and in laboratory experiments under controlled, artificial light. In shallow, still-water and under direct solar radiation, measurement discrepancies between exposed and shielded sensors averaged 0.4 °C but can reach 1.6 °C. Around 0.3 °C of this inconsistency is explained by variance in measurement accuracy between sensors; the remainder is attributed to solar radiation. Discrepancies were found to increase with light intensity, but to attain Tw differences in excess of 0.5 °C requires direct, bright solar radiation (>400 W m−2 in the total spectrum. Under laboratory conditions, radiative errors are an order of magnitude lower when thermistors are placed in flowing water (even at velocities as low as 0.1 m s−1. Radiative errors were also modest relative to the discrepancy between different thermistor manufacturers. Based on these controlled experiments, a set of guidelines are recommended for deploying thermistor arrays in water bodies.

Radiation Resistance Test of Wireless Sensor Node and the Radiation Shielding Calculation

Energy Technology Data Exchange (ETDEWEB)

Li, Liqan; Sur, Bhaskar [Atomic Energy of Canada Limited, Ontario (Canada); Wang, Quan [University of Western Ontario, Ontario (Canada); Deng, Changjian [The University of Electronic Science and Technology, Chengdu (China); Chen, Dongyi; Jiang, Jin [Applied Physics Branch, Ontario (Korea, Republic of)

2014-08-15

A wireless sensor network (WSN) is being developed for nuclear power plants. Amongst others, ionizing radiation resistance is one essential requirement for WSN to be successful. This paper documents the work done in Chalk River Laboratories of Atomic Energy of Canada Limited (AECL) to test the resistance to neutron and gamma radiation of some WSN nodes. The recorded dose limit that the nodes can withstand before being damaged by the radiation is compared with the radiation environment inside a typical CANDU (CANada Deuterium Uranium) power plant reactor building. Shielding effects of polyethylene, cadmium and lead to neutron and gamma radiations are also analyzed using MCNP simulation. The shielding calculation can be a reference for the node case design when high dose rate or accidental condition (like Fukushima) is to be considered.

Radiation hard silicon sensors for the CMS tracker upgrade

CERN Document Server

Pohlsen, Thomas

2013-01-01

At an instantaneous luminosity of $5 \\times 10^{34}$ cm$^{-2}$ s$^{-1}$, the high-luminosity phase of the Large Hadron Collider (HL-LHC) is expected to deliver a total of $3\\,000$ fb$^{-1}$ of collisions, hereby increasing the discovery potential of the LHC experiments significantly. However, the radiation dose of the tracking systems will be severe, requiring new radiation hard sensors for the CMS tracker. The CMS tracker collaboration has initiated a large material investigation and irradiation campaign to identify the silicon material and design that fulfils all requirements for detectors for the HL-LHC. Focussing on the upgrade of the outer tracker region, pad sensors as well as fully functional strip sensors have been implemented on silicon wafers with different material properties and thicknesses. The samples were irradiated with a mixture of neutrons and protons corresponding to fluences as expected for the positions of detector layers in the future tracker. Different proton energies were used for irr...

Energy Dependence of Proton Radiation Damage in Si-Sensors

CERN Document Server

AUTHOR|(CDS)2084399; Neubüser, C.

2014-01-01

Irradiation experiments on silicon sensors are used to mimic the radiation environment at collider experiments with the aim to forecast the change of the electrical properties of a detector with irradiation. Measurements on irradiated sensors are invaluable in choosing a material well suited for a silicon tracking detector. This is especially true for the upgraded detectors to be used in the high-luminosity phase of the LHC (HL-LHC), where silicon sensors as currently used would suffer severe loss in signal from irradiation with charged and neutral hadrons.\\\\ The CMS Tracker Collaboration has initiated irradiation studies with protons with energies ranging from 23 MeV to 23 GeV. They are often used instead of charged hadrons, their radiation induced damage to the silicon being rather similar. However, in oxygen rich silicon, NIEL violation concerning the full depletion voltage has been observed.\\\\ In this paper results from investigations on bulk defects compared to the change of the electrical properties of ...

A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

Energy Technology Data Exchange (ETDEWEB)

Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

2015-12-15

We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

Broadband illumination of superconducting pair breaking photon detectors

International Nuclear Information System (INIS)

Guruswamy, T; Goldie, D J; Withington, S

2016-01-01

Understanding the detailed behaviour of superconducting pair breaking photon detectors such as Kinetic Inductance Detectors (KIDs) requires knowledge of the nonequilibrium quasiparticle energy distributions. We have previously calculated the steady state distributions resulting from uniform absorption of monochromatic sub gap and above gap frequency radiation by thin films. In this work, we use the same methods to calculate the effect of illumination by broadband sources, such as thermal radiation from astrophysical phenomena or from the readout system. Absorption of photons at multiple above gap frequencies is shown to leave unchanged the structure of the quasiparticle energy distribution close to the superconducting gap. Hence for typical absorbed powers, we find the effects of absorption of broadband pair breaking radiation can simply be considered as the sum of the effects of absorption of many monochromatic sources. Distribution averaged quantities, like quasiparticle generation efficiency η, match exactly a weighted average over the bandwidth of the source of calculations assuming a monochromatic source. For sub gap frequencies, however, distributing the absorbed power across multiple frequencies does change the low energy quasiparticle distribution. For moderate and high absorbed powers, this results in a significantly larger η–a higher number of excess quasiparticles for a broadband source compared to a monochromatic source of equal total absorbed power. Typically in KIDs the microwave power absorbed has a very narrow bandwidth, but in devices with broad resonance characteristics (low quality factors), this increase in η may be measurable. (paper)

Nuclear radiation sensors and monitoring following a nuclear or radiological emergencies

International Nuclear Information System (INIS)

Bhatnagar, P.K.

2009-01-01

Management of Nuclear and Radiological Emergencies arising from Radiological Dispersive Device (RDD), Improvised Nuclear Devices (IND), Nuclear Reactors/Power plants and Nuclear War require measurement of ionizing radiations and radioactivity on an enhanced scale relative to the levels encountered in peaceful uses of ionizing radiations and radioactivity. It is heartening that since Hiroshima, Nagasaki nuclear disaster, the world has been quiet but since early 2000 there has been a fear of certain devices to be used by terrorists, which could lead to panic, and disaster due to dispersal of radioactivity by RDD, IND. Nuclear attack would lead to blast, thermal, initial nuclear radiation, nuclear fall out leading to gamma and neutron dose, dose rates in range from few R, R/h to kR, kR/h, and determinations of k Bq or higher order. Such situations have been visualized at national levels and National Disaster Management Authority NDMA has been established and Disaster Management Act 2005 has come into existence. NDMA has prepared guidelines for Nuclear and radiological emergency management highlighting preparedness, mitigation, response, capacity building, etc. Critical point in all these issues is detection of emergency, quick intimation to the concerned for action in shortest possible time. Upper most requirement by those involved in pursuing action, is radiation sensor based radiation monitors for personnel, area, and to assess contamination due to radioactivity.This presentation briefly describes the Indian scenario in the development of the radiation sensors and the sensor-based radiation monitors. (author)

Nuclear radiation sensors and monitoring following a nuclear or radiological emergencies

Energy Technology Data Exchange (ETDEWEB)

Bhatnagar, P K [Defence Laboratory, Jodhpur (India)

2009-01-15

Management of Nuclear and Radiological Emergencies arising from Radiological Dispersive Device (RDD), Improvised Nuclear Devices (IND), Nuclear Reactors/Power plants and Nuclear War require measurement of ionizing radiations and radioactivity on an enhanced scale relative to the levels encountered in peaceful uses of ionizing radiations and radioactivity. It is heartening that since Hiroshima, Nagasaki nuclear disaster, the world has been quiet but since early 2000 there has been a fear of certain devices to be used by terrorists, which could lead to panic, and disaster due to dispersal of radioactivity by RDD, IND. Nuclear attack would lead to blast, thermal, initial nuclear radiation, nuclear fall out leading to gamma and neutron dose, dose rates in range from few R, R/h to kR, kR/h, and determinations of k Bq or higher order. Such situations have been visualized at national levels and National Disaster Management Authority NDMA has been established and Disaster Management Act 2005 has come into existence. NDMA has prepared guidelines for Nuclear and radiological emergency management highlighting preparedness, mitigation, response, capacity building, etc. Critical point in all these issues is detection of emergency, quick intimation to the concerned for action in shortest possible time. Upper most requirement by those involved in pursuing action, is radiation sensor based radiation monitors for personnel, area, and to assess contamination due to radioactivity.This presentation briefly describes the Indian scenario in the development of the radiation sensors and the sensor-based radiation monitors. (author)

Total dose radiation effects of pressure sensors fabricated on uni-bond-SOI materials

International Nuclear Information System (INIS)

Zhu Shiyang; Huang Yiping; Wang Jin; Li Anzhen; Shen Shaoqun; Bao Minhang

2001-01-01

Piezoresistive pressure sensors with a twin-island structure were successfully fabricated using high quality Uni-bond-SOI (On Insulator) materials. Since the piezoresistors were structured by the single crystalline silicon overlayer of the SOI wafer and were totally isolated by the buried SiO 2 , the sensors are radiation-hard. The sensitivity and the linearity of the pressure sensors keep their original values after being irradiated by 60 Co γ-rays up to 2.3 x 10 4 Gy(H 2 O). However, the offset voltage of the sensor has a slight drift, increasing with the radiation dose. The absolute value of the offset voltage deviation depends on the pressure sensor itself. For comparison, corresponding polysilicon pressure sensors were fabricated using the similar process and irradiated at the same condition

Design of a radiation hard silicon pixel sensor for X-ray science

Energy Technology Data Exchange (ETDEWEB)

Schwandt, Joern

2014-06-15

At DESY Hamburg the European X-ray Free-Electron Laser (EuXFEL) is presently under construction. The EuXFEL has unique properties with respect to X-ray energy, instantaneous intensity, pulse length, coherence and number of pulses/sec. These properties of the EuXFEL pose very demanding requirements for imaging detectors. One of the detector systems which is currently under development to meet these challenges is the Adaptive Gain Integrating Pixel Detector, AGIPD. It is a hybrid pixel-detector system with 1024 x 1024 p{sup +} pixels of dimensions 200 μm x 200 μm, made of 16 p{sup +}nn{sup +}- silicon sensors, each with 10.52 cm x 2.56 cm sensitive area and 500 μm thickness. The particular requirements for the AGIPD are a separation between noise and single photons down to energies of 5 keV, more than 10{sup 4} photons per pixel for a pulse duration of less than 100 fs, negligible pile-up at the EuXFEL repetition rate of 4.5 MHz, operation for X-ray doses up to 1 GGy, good efficiency for X-rays with energies between 5 and 20 keV, and minimal inactive regions at the edges. The main challenge in the sensor design is the required radiation tolerance and high operational voltage, which is required to reduce the so-called plasma effect. This requires a specially optimized sensor. The X-ray radiation damage results in a build-up of oxide charges and interface traps which lead to a reduction of the breakdown voltage, increased leakage current, increased interpixel capacitances and charge losses. Extensive TCAD simulations have been performed to understand the impact of X-ray radiation damage on the detector performance and optimize the sensor design. To take radiation damage into account in the simulation, radiation damage parameters have been determined on MOS capacitors and gate-controlled diodes as function of dose. The optimized sensor design was fabricated by SINTEF. Irradiation tests on test structures and sensors show that the sensor design is radiation hard and

An investigation of medical radiation detection using CMOS image sensors in smartphones

Energy Technology Data Exchange (ETDEWEB)

Kang, Han Gyu [Department of Senior Healthcare, Graduate School of Eulji University, Daejeon 301-746 (Korea, Republic of); Song, Jae-Jun [Department of Otorhinolaryngology-Head & Neck Surgery, Korea University, Guro Hospital,148, Gurodong-ro, Guro-gu, Seoul 152-703 (Korea, Republic of); Lee, Kwonhee [Graduate Program in Bio-medical Science, Korea University, 2511 Sejong-ro, Sejong City 339-770 (Korea, Republic of); Nam, Ki Chang [Department of Medical Engineering, College of Medicine, Dongguk University, 32 Dongguk-ro, Goyang-si, Gyeonggi-do 410-820 (Korea, Republic of); Hong, Seong Jong; Kim, Ho Chul [Department of Radiological Science, Eulji University, 553 Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 431-713 (Korea, Republic of)

2016-07-01

Medical radiation exposure to patients has increased with the development of diagnostic X-ray devices and multi-channel computed tomography (CT). Despite the fact that the low-dose CT technique can significantly reduce medical radiation exposure to patients, the increasing number of CT examinations has increased the total medical radiation exposure to patients. Therefore, medical radiation exposure to patients should be monitored to prevent cancers caused by diagnostic radiation. However, without using thermoluminescence or glass dosimeters, it is hardly measure doses received by patients during medical examinations accurately. Hence, it is necessary to develop radiation monitoring devices and algorithms that are reasonably priced and have superior radiation detection efficiencies. The aim of this study is to investigate the feasibility of medical dose measurement using complementary metal oxide semiconductor (CMOS) sensors in smartphone cameras with an algorithm to extract the X-ray interacted pixels. We characterized the responses of the CMOS sensors in a smartphone with respect to the X-rays generated by a general diagnostic X-ray system. The characteristics of the CMOS sensors in a smartphone camera, such as dose response linearity, dose rate dependence, energy dependence, angular dependence, and minimum detectable activity were evaluated. The high energy gamma-ray of 662 keV from Cs-137 can be detected using the smartphone camera. The smartphone cameras which employ the developed algorithm can detect medical radiations.

An investigation of medical radiation detection using CMOS image sensors in smartphones

International Nuclear Information System (INIS)

Kang, Han Gyu; Song, Jae-Jun; Lee, Kwonhee; Nam, Ki Chang; Hong, Seong Jong; Kim, Ho Chul

2016-01-01

Medical radiation exposure to patients has increased with the development of diagnostic X-ray devices and multi-channel computed tomography (CT). Despite the fact that the low-dose CT technique can significantly reduce medical radiation exposure to patients, the increasing number of CT examinations has increased the total medical radiation exposure to patients. Therefore, medical radiation exposure to patients should be monitored to prevent cancers caused by diagnostic radiation. However, without using thermoluminescence or glass dosimeters, it is hardly measure doses received by patients during medical examinations accurately. Hence, it is necessary to develop radiation monitoring devices and algorithms that are reasonably priced and have superior radiation detection efficiencies. The aim of this study is to investigate the feasibility of medical dose measurement using complementary metal oxide semiconductor (CMOS) sensors in smartphone cameras with an algorithm to extract the X-ray interacted pixels. We characterized the responses of the CMOS sensors in a smartphone with respect to the X-rays generated by a general diagnostic X-ray system. The characteristics of the CMOS sensors in a smartphone camera, such as dose response linearity, dose rate dependence, energy dependence, angular dependence, and minimum detectable activity were evaluated. The high energy gamma-ray of 662 keV from Cs-137 can be detected using the smartphone camera. The smartphone cameras which employ the developed algorithm can detect medical radiations.

Fiber-based broadband black-light source

OpenAIRE

Sylvestre , Thibaut; Lee , Min Won; Ragueh , A. R.; Stiller , Birgit; Fanjoux , Gil; Barviau , B.; Mussot , A.; Kudlinski , A.

2012-01-01

International audience; Black-Light or Wood's lamp refers to sources that emit long-wavelength ultraviolet radiation (UV-A) from 315 nm and little visible light till 410 nm (blue). In this paper, we present a new fibre-based source of "black light", a source that emits broadband ultraviolet radiation but only small amounts of visible light and no infrared light. We made this source by pumping a specially designed silica photonic crystal fibre (PCF) with 355 nm light pulses from a Q-switched f...

Vulnerability of OFDR-based distributed sensors to radiations

Energy Technology Data Exchange (ETDEWEB)

Rizzolo, S. [Laboratoire Hubert Curien, Universite Jean Monnet, CNRS UMR 5516, 18 Rue Benoit Lauras, 42000, Saint-Etienne (France); Dipartimento di Fisica e Chimica, Universita di Palermo, Viale delle Scienze Parco d' Orleans II, Ed. 17, 90128 Palermo (Italy); Areva Centre Technique, Boulevard de l' Industrie, 71200, Le Creusot (France); Boukenter, A.; Marin, E.; Ouerdane, Y.; Girard, S. [Laboratoire Hubert Curien, Universite Jean Monnet, CNRS UMR 5516, 18 Rue Benoit Lauras, 42000, Saint-Etienne (France); Cannas, M. [Dipartimento di Fisica e Chimica, Universita di Palermo, Viale delle Scienze Parco d' Orleans II, Ed. 17, 90128 Palermo (Italy); Perisse, J. [Areva NP, 10 Rue Juliette Recamier, 69006, Lyon (France); Bauer, S. [Areva Centre Technique, Boulevard de l' Industrie, 71200, Le Creusot (France); Mace, J.R. [Areva NP, 1, Place Jean-Millier 92084, Paris-La Defense (France)

2015-07-01

overcome the issues identified for next generation of NPPs. Such integration will only be possible if the OFDR based systems are able to resist to the constraints associated with industrial environments, one of the most constraining being the presence of high level of radiations. In this work, we carry out a systematic study to highlight the OFDR interest and sensitivity to probe the optical samples at high irradiation dose levels. The responses of five optical fibers types, from radiation hardened to radiation sensitive ones, are investigated to explore the influence of both the material compositions and the γ-irradiation on the ODFR sensors. Using these samples, we should highlight the influence of the core dopant concentration on the observed radiation-induced changes as well as the difference observed when the cladding is either radiation resistant or radiation sensitive. Our samples were irradiated using a {sup 60}Co source facility reaching total doses varying from 1 MGy up to a maximum of 10 MGy. All the measurements are performed after diverse months from irradiation to study permanents effects induced from these high γ-rays doses. We'll present at the conference all the experimental results acquired and use them to estimate the potential of OFDR-based systems for operation in radiation environments. (authors)

Broadband terahertz generation using the semiconductor-metal transition in VO2

Directory of Open Access Journals (Sweden)

Nicholas A. Charipar

2016-01-01

Full Text Available We report the design, fabrication, and characterization of broadband terahertz emitters based on the semiconductor-metal transition in thin film VO2 (vanadium dioxide. With the appropriate geometry, picosecond electrical pulses are generated by illuminating 120 nm thick VO2 with 280 fs pulses from a femtosecond laser. These ultrafast electrical pulses are used to drive a simple dipole antenna, generating broadband terahertz radiation.

Effective polycrystalline sensor of ultraviolet radiation

Directory of Open Access Journals (Sweden)

S.Yu. Pavelets

2017-10-01

Full Text Available Deposition of special thin layers with high and low resistance in space charge region of surface barrier photoconverters based on the p-Cu1.8S/n-CdS structure leads to a sufficient increase in photosensitivity and decrease in dark tunneling-recombination current. Highly efficient and stable polycrystalline photoconverters of ultraviolet radiation based on polycrystalline CdS have been obtained. Electrical and photoelectric properties have been investigated, and the main operational parameters of ultraviolet sensors have been adduced. The reasons for high stability of the parameters inherent to the p-Cu1.8S/n-CdS sensors are as follows: the absence of impurity components additionally doped to the barrier structure and stability of the photocurrent photoemission component.

Experimental checking results of mathematical modeling of the radiation environment sensor based on diamond detectors

International Nuclear Information System (INIS)

Gladchenkov, E V; Kolyubin, V A; Nedosekin, P G; Zaharchenko, K V; Ibragimov, R F; Kadilin, V V; Tyurin, E M

2017-01-01

Were conducted a series of experiments, the purpose of which had to verify the mathematical model of the radiation environment sensor. Theoretical values of the beta particles count rate from 90 Sr - 90 Y source registered by radiation environment sensor was compared with the experimental one. Theoretical (calculated) count rate of beta particles was found with using the developed mathematical model of the radiation environment sensor. Deviation of the calculated values of the beta particle count rate does not exceed 10% from the experimental. (paper)

Optimizing UV Index determination from broadband irradiances

Science.gov (United States)

Tereszchuk, Keith A.; Rochon, Yves J.; McLinden, Chris A.; Vaillancourt, Paul A.

2018-03-01

A study was undertaken to improve upon the prognosticative capability of Environment and Climate Change Canada's (ECCC) UV Index forecast model. An aspect of that work, and the topic of this communication, was to investigate the use of the four UV broadband surface irradiance fields generated by ECCC's Global Environmental Multiscale (GEM) numerical prediction model to determine the UV Index. The basis of the investigation involves the creation of a suite of routines which employ high-spectral-resolution radiative transfer code developed to calculate UV Index fields from GEM forecasts. These routines employ a modified version of the Cloud-J v7.4 radiative transfer model, which integrates GEM output to produce high-spectral-resolution surface irradiance fields. The output generated using the high-resolution radiative transfer code served to verify and calibrate GEM broadband surface irradiances under clear-sky conditions and their use in providing the UV Index. A subsequent comparison of irradiances and UV Index under cloudy conditions was also performed. Linear correlation agreement of surface irradiances from the two models for each of the two higher UV bands covering 310.70-330.0 and 330.03-400.00 nm is typically greater than 95 % for clear-sky conditions with associated root-mean-square relative errors of 6.4 and 4.0 %. However, underestimations of clear-sky GEM irradiances were found on the order of ˜ 30-50 % for the 294.12-310.70 nm band and by a factor of ˜ 30 for the 280.11-294.12 nm band. This underestimation can be significant for UV Index determination but would not impact weather forecasting. Corresponding empirical adjustments were applied to the broadband irradiances now giving a correlation coefficient of unity. From these, a least-squares fitting was derived for the calculation of the UV Index. The resultant differences in UV indices from the high-spectral-resolution irradiances and the resultant GEM broadband irradiances are typically within 0

Direct UV-written broadband directional broadband planar waveguide couplers

DEFF Research Database (Denmark)

Olivero, Massimo; Svalgaard, Mikael

2005-01-01

We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation.......We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation....

Numerical and experimental studies of mechanisms underlying the effect of pulsed broadband terahertz radiation on nerve cells

Energy Technology Data Exchange (ETDEWEB)

Duka, M V; Dvoretskaya, L N; Babelkin, N S; Khodzitskii, M K; Chivilikhin, S A; Smolyanskaya, O A [St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg (Russian Federation)

2014-08-31

We have studied the mechanisms underlying the effect of pulsed broadband terahertz radiation on the growth of neurites of sensory ganglia using a comparative analysis of measured reflection spectra of ganglion neurites (in the frequency range 0.1 – 2.0 THz) and spectra obtained by numerical simulation with CST Microwave Studio. The observed changes are shown to be mainly due to pulse energy absorption in the ganglion neurites. Of particular interest are the observed single resonance frequencies related to resonance size effects, which can be used to irradiate ganglia in order to activate their growth. (laser biophotonics)

Study of surface properties of ATLAS12 strip sensors and their radiation resistance

Energy Technology Data Exchange (ETDEWEB)

Mikestikova, M., E-mail: mikestik@fzu.cz [Academy of Sciences of the Czech Republic, Institute of Physics, Na Slovance 2, 18221 Prague 8 (Czech Republic); Allport, P.P.; Baca, M.; Broughton, J.; Chisholm, A.; Nikolopoulos, K.; Pyatt, S.; Thomas, J.P.; Wilson, J.A. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Kierstead, J.; Kuczewski, P.; Lynn, D. [Brookhaven National Laboratory, Physics Department and Instrumentation Division, Upton, NY 11973-5000 (United States); Hommels, L.B.A. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Ullan, M. [Centro Nacional de Microelectronica (IMB-CNM, CSIC), Campus UAB-Bellaterra, 08193 Barcelona (Spain); Bloch, I.; Gregor, I.M.; Tackmann, K. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Hauser, M.; Jakobs, K.; Kuehn, S. [Physikalisches Institut, Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); and others

2016-09-21

A radiation hard n{sup +}-in-p micro-strip sensor for the use in the Upgrade of the strip tracker of the ATLAS experiment at the High Luminosity Large Hadron Collider (HL-LHC) has been developed by the “ATLAS ITk Strip Sensor collaboration” and produced by Hamamatsu Photonics. Surface properties of different types of end-cap and barrel miniature sensors of the latest sensor design ATLAS12 have been studied before and after irradiation. The tested barrel sensors vary in “punch-through protection” (PTP) structure, and the end-cap sensors, whose stereo-strips differ in fan geometry, in strip pitch and in edge strip ganging options. Sensors have been irradiated with proton fluences of up to 1×10{sup 16} n{sub eq}/cm{sup 2}, by reactor neutron fluence of 1×10{sup 15} n{sub eq}/cm{sup 2} and by gamma rays from {sup 60}Co up to dose of 1 MGy. The main goal of the present study is to characterize the leakage current for micro-discharge breakdown voltage estimation, the inter-strip resistance and capacitance, the bias resistance and the effectiveness of PTP structures as a function of bias voltage and fluence. It has been verified that the ATLAS12 sensors have high breakdown voltage well above the operational voltage which implies that different geometries of sensors do not influence their stability. The inter-strip isolation is a strong function of irradiation fluence, however the sensor performance is acceptable in the expected range for HL-LHC. New gated PTP structure exhibits low PTP onset voltage and sharp cut-off of effective resistance even at the highest tested radiation fluence. The inter-strip capacitance complies with the technical specification required before irradiation and no radiation-induced degradation was observed. A summary of ATLAS12 sensors tests is presented including a comparison of results from different irradiation sites. The measured characteristics are compared with the previous prototype of the sensor design, ATLAS07. - Highlights: �

Development of compact long-term broadband ocean bottom seismometer for seafloor observation of slow earthquakes

Science.gov (United States)

Yamashita, Y.; Shinohara, M.; Yamada, T.; Shiobara, H.

2017-12-01

It is important to understand coupling between plates in a subduction zone for studies of earthquake generation. Recently low frequency tremor and very low frequency earthquake (VLFE) were discovered in plate boundary near a trench. These events (slow earthquakes) in shallow plate boundary should be related to slow slip on a plate boundary. For observation of slow earthquakes, Broad Band Ocean Bottom Seismometer (BBOBS) is useful, however a number of BBOBSs are limited due to cost. On the other hand, a number of Long-term OBSs (LT-OBSs) with recording period of one year are available. However, the LT-OBS has seismometer with a natural period of 1 second. Therefore frequency band of observation is slightly narrow for slow earthquakes. Therefore we developed a compact long-term broad-band OBS by replacement of the seismic sensor of the LT-OBSs to broadband seismometer.We adopted seismic sensor with natural period of 20 seconds (Trillium Compact Broadband Seismometer, Nanometrics). Because tilt of OBS on seafloor can not be controlled due to free-fall, leveling system for seismic sensor is necessary. The broadband seismic senor has cylinder shape with diameter of 90 mm and height of 100 mm, and the developed levelling system can mount the seismic sensor with no modification of shape. The levelling system has diameter of 160 mm and height of 110 mm, which is the same size as existing levelling system of the LT-OBS. The levelling system has two horizontal axes and each axis is driven by motor. Leveling can be performed up to 20 degrees by using micro-processor (Arduino). Resolution of levelling is less than one degree. The system immediately starts leveling by the power-on of controller. After levelling, the the seismic senor is powered and the controller records angles of levelling to SD RAM. Then the controller is shut down to consume no power. Compact long-term broadband ocean bottom seismometer is useful for observation of slow earthquakes on seafloor. In addition

Radiation-stimulated processes in transistor temperature sensors

International Nuclear Information System (INIS)

Pavlyk, B. V.; Grypa, A. S.

2016-01-01

The features of the radiation-stimulated changes in the I–V and C–V characteristics of the emitter–base junction in KT3117 transistors are considered. It is shown that an increase in the current through the emitter junction is observed at the initial stage of irradiation (at doses of D < 4000 Gy for the “passive” irradiation mode and D < 5200 Gy for the “active” mode), which is caused by the effect of radiation-stimulated ordering of the defect-containing structure of the p–n junction. It is also shown that the X-ray irradiation (D < 14000 Gy), the subsequent relaxation (96 h), and thermal annealing (2 h at 400 K) of the transistor temperature sensors under investigation result in an increase in their radiation resistance.

First tests of a novel radiation hard CMOS sensor process for Depleted Monolithic Active Pixel Sensors

Science.gov (United States)

Pernegger, H.; Bates, R.; Buttar, C.; Dalla, M.; van Hoorne, J. W.; Kugathasan, T.; Maneuski, D.; Musa, L.; Riedler, P.; Riegel, C.; Sbarra, C.; Schaefer, D.; Schioppa, E. J.; Snoeys, W.

2017-06-01

The upgrade of the ATLAS [1] tracking detector for the High-Luminosity Large Hadron Collider (LHC) at CERN requires novel radiation hard silicon sensor technologies. Significant effort has been put into the development of monolithic CMOS sensors but it has been a challenge to combine a low capacitance of the sensing node with full depletion of the sensitive layer. Low capacitance brings low analog power. Depletion of the sensitive layer causes the signal charge to be collected by drift sufficiently fast to separate hits from consecutive bunch crossings (25 ns at the LHC) and to avoid losing the charge by trapping. This paper focuses on the characterization of charge collection properties and detection efficiency of prototype sensors originally designed in the framework of the ALICE Inner Tracking System (ITS) upgrade [2]. The prototypes are fabricated both in the standard TowerJazz 180nm CMOS imager process [3] and in an innovative modification of this process developed in collaboration with the foundry, aimed to fully deplete the sensitive epitaxial layer and enhance the tolerance to non-ionizing energy loss. Sensors fabricated in standard and modified process variants were characterized using radioactive sources, focused X-ray beam and test beams before and after irradiation. Contrary to sensors manufactured in the standard process, sensors from the modified process remain fully functional even after a dose of 1015neq/cm2, which is the the expected NIEL radiation fluence for the outer pixel layers in the future ATLAS Inner Tracker (ITk) [4].

First tests of a novel radiation hard CMOS sensor process for Depleted Monolithic Active Pixel Sensors

International Nuclear Information System (INIS)

Pernegger, H.; Hoorne, J.W. van; Kugathasan, T.; Musa, L.; Riedler, P.; Riegel, C.; Schaefer, D.; Schioppa, E.J.; Snoeys, W.; Bates, R.; Buttar, C.; Maneuski, D.; Dalla, M.; Sbarra, C.

2017-01-01

The upgrade of the ATLAS [1] tracking detector for the High-Luminosity Large Hadron Collider (LHC) at CERN requires novel radiation hard silicon sensor technologies. Significant effort has been put into the development of monolithic CMOS sensors but it has been a challenge to combine a low capacitance of the sensing node with full depletion of the sensitive layer. Low capacitance brings low analog power. Depletion of the sensitive layer causes the signal charge to be collected by drift sufficiently fast to separate hits from consecutive bunch crossings (25 ns at the LHC) and to avoid losing the charge by trapping. This paper focuses on the characterization of charge collection properties and detection efficiency of prototype sensors originally designed in the framework of the ALICE Inner Tracking System (ITS) upgrade [2]. The prototypes are fabricated both in the standard TowerJazz 180nm CMOS imager process [3] and in an innovative modification of this process developed in collaboration with the foundry, aimed to fully deplete the sensitive epitaxial layer and enhance the tolerance to non-ionizing energy loss. Sensors fabricated in standard and modified process variants were characterized using radioactive sources, focused X-ray beam and test beams before and after irradiation. Contrary to sensors manufactured in the standard process, sensors from the modified process remain fully functional even after a dose of 10"1"5 n _e_q/cm"2, which is the the expected NIEL radiation fluence for the outer pixel layers in the future ATLAS Inner Tracker (ITk) [4].

Low power consumption and high temperature durability for radiation sensor

International Nuclear Information System (INIS)

Matsumoto, Yoshinori; Ueno, Hiroto

2015-01-01

Low power consumption and high temperature operation are important in an environmental monitoring system. The power consumption of 3 mW is achieved for the radiation sensor using low voltage operational amplifier and comparator in the signal processing circuit. The leakage reverse current of photodiode causes the charge amplifier saturation over 50degC. High temperature durability was improved by optimizing the circuit configuration and the values of feedback resistance and capacitance in the charge amplifier. The pulse response of the radiation sensor was measured up to 55degC. The custom detection circuit was designed by 0.6 μm CMOS process at 5-V supply voltage. The operation temperature was improved up to 65degC. (author)

Electric field deformation in diamond sensors induced by radiation defects

Energy Technology Data Exchange (ETDEWEB)

Kassel, Florian; Boer, Wim de; Boegelspacher, Felix; Dierlamm, Alexander; Mueller, Thomas; Steck, Pia [Institut fuer Experimentelle Kernphysik (IEKP), Karlsruher Institut fuer Technologie (KIT) (Germany); Dabrowski, Anne; Guthoff, Moritz [CERN (Switzerland)

2016-07-01

The BCML system is a beam monitoring device in the CMS experiment at the LHC. As detectors 32 poly-crystalline CVD diamond sensors are positioned in a ring around the beam pipe at a distance of ±1.8 m and ±14.4 m from the interaction point. The radiation hardness of the diamond sensors in terms of measured signal during operation was significantly lower than expected from laboratory measurements. At high particle rates, such as those occurring during the operation of the LHC, a significant fraction of the defects act as traps for charge carriers. This space charge modifies the electrical field in the sensor bulk leading to a reduction of the charge collection efficiency (CCE). A diamond irradiation campaign was started to investigate the rate dependent electrical field deformation with respect to the radiation damage. Besides the electrical field measurements via the Transient Current Technique, the CCE was measured. The experimental results were used to create an effective trap model that takes the radiation damage into account. Using this trap model the rate dependent electrical field deformation and the CCE were simulated with the software ''SILVACO TCAD''. This talk compares the experimental measurement results with the simulations.

Multidirectional seismo-acoustic wavefield of strombolian explosions at Yasur, Vanuatu using a broadband seismo-acoustic network, infrasound arrays, and infrasonic sensors on tethered balloons

Science.gov (United States)

Matoza, R. S.; Jolly, A. D.; Fee, D.; Johnson, R.; Kilgour, G.; Christenson, B. W.; Garaebiti, E.; Iezzi, A. M.; Austin, A.; Kennedy, B.; Fitzgerald, R.; Key, N.

2016-12-01

Seismo-acoustic wavefields at volcanoes contain rich information on shallow magma transport and subaerial eruption processes. Acoustic wavefields from eruptions are predicted to be directional, but sampling this wavefield directivity is challenging because infrasound sensors are usually deployed on the ground surface. We attempt to overcome this observational limitation using a novel deployment of infrasound sensors on tethered balloons in tandem with a suite of dense ground-based seismo-acoustic, geochemical, and eruption imaging instrumentation. We present preliminary results from a field experiment at Yasur Volcano, Vanuatu from July 26th to August 4th 2016. Our observations include data from a temporary network of 11 broadband seismometers, 6 single infrasonic microphones, 7 small-aperture 3-element infrasound arrays, 2 infrasound sensor packages on tethered balloons, an FTIR, a FLIR, 2 scanning Flyspecs, and various visual imaging data. An introduction to the dataset and preliminary analysis of the 3D seismo-acoustic wavefield and source process will be presented. This unprecedented dataset should provide a unique window into processes operating in the shallow magma plumbing system and their relation to subaerial eruption dynamics.

Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

Science.gov (United States)

Bore, Thierry; Wagner, Norman; Delepine Lesoille, Sylvie; Taillade, Frederic; Six, Gonzague; Daout, Franck; Placko, Dominique

2016-01-01

Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock) and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM) to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling. PMID:27096865

Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

Directory of Open Access Journals (Sweden)

Thierry Bore

2016-04-01

Full Text Available Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling.

Develop of BiI3 sensors for imagenology of radiations to ambient temperature

International Nuclear Information System (INIS)

Aguiar, I.

2008-01-01

The mastery refers to the obtention of images with radiations. The subject in study to be used as sensor of those radiations in the triodide of bismuth, since its properties makes it appropriate for the detections of ionizing and infrared radiation

Study of surface properties of ATLAS12 strip sensors and their radiation resistance

Science.gov (United States)

Mikestikova, M.; Allport, P. P.; Baca, M.; Broughton, J.; Chisholm, A.; Nikolopoulos, K.; Pyatt, S.; Thomas, J. P.; Wilson, J. A.; Kierstead, J.; Kuczewski, P.; Lynn, D.; Hommels, L. B. A.; Ullan, M.; Bloch, I.; Gregor, I. M.; Tackmann, K.; Hauser, M.; Jakobs, K.; Kuehn, S.; Mahboubi, K.; Mori, R.; Parzefall, U.; Clark, A.; Ferrere, D.; Sevilla, S. Gonzalez; Ashby, J.; Blue, A.; Bates, R.; Buttar, C.; Doherty, F.; McMullen, T.; McEwan, F.; O'Shea, V.; Kamada, S.; Yamamura, K.; Ikegami, Y.; Nakamura, K.; Takubo, Y.; Unno, Y.; Takashima, R.; Chilingarov, A.; Fox, H.; Affolder, A. A.; Casse, G.; Dervan, P.; Forshaw, D.; Greenall, A.; Wonsak, S.; Wormald, M.; Cindro, V.; Kramberger, G.; Mandić, I.; Mikuž, M.; Gorelov, I.; Hoeferkamp, M.; Palni, P.; Seidel, S.; Taylor, A.; Toms, K.; Wang, R.; Hessey, N. P.; Valencic, N.; Hanagaki, K.; Dolezal, Z.; Kodys, P.; Bohm, J.; Stastny, J.; Bevan, A.; Beck, G.; Milke, C.; Domingo, M.; Fadeyev, V.; Galloway, Z.; Hibbard-Lubow, D.; Liang, Z.; Sadrozinski, H. F.-W.; Seiden, A.; To, K.; French, R.; Hodgson, P.; Marin-Reyes, H.; Parker, K.; Jinnouchi, O.; Hara, K.; Sato, K.; Hagihara, M.; Iwabuchi, S.; Bernabeu, J.; Civera, J. V.; Garcia, C.; Lacasta, C.; Marti i Garcia, S.; Rodriguez, D.; Santoyo, D.; Solaz, C.; Soldevila, U.

2016-09-01

A radiation hard n+-in-p micro-strip sensor for the use in the Upgrade of the strip tracker of the ATLAS experiment at the High Luminosity Large Hadron Collider (HL-LHC) has been developed by the "ATLAS ITk Strip Sensor collaboration" and produced by Hamamatsu Photonics. Surface properties of different types of end-cap and barrel miniature sensors of the latest sensor design ATLAS12 have been studied before and after irradiation. The tested barrel sensors vary in "punch-through protection" (PTP) structure, and the end-cap sensors, whose stereo-strips differ in fan geometry, in strip pitch and in edge strip ganging options. Sensors have been irradiated with proton fluences of up to 1×1016 neq/cm2, by reactor neutron fluence of 1×1015 neq/cm2 and by gamma rays from 60Co up to dose of 1 MGy. The main goal of the present study is to characterize the leakage current for micro-discharge breakdown voltage estimation, the inter-strip resistance and capacitance, the bias resistance and the effectiveness of PTP structures as a function of bias voltage and fluence. It has been verified that the ATLAS12 sensors have high breakdown voltage well above the operational voltage which implies that different geometries of sensors do not influence their stability. The inter-strip isolation is a strong function of irradiation fluence, however the sensor performance is acceptable in the expected range for HL-LHC. New gated PTP structure exhibits low PTP onset voltage and sharp cut-off of effective resistance even at the highest tested radiation fluence. The inter-strip capacitance complies with the technical specification required before irradiation and no radiation-induced degradation was observed. A summary of ATLAS12 sensors tests is presented including a comparison of results from different irradiation sites. The measured characteristics are compared with the previous prototype of the sensor design, ATLAS07.

Adoption of Broadband Services

DEFF Research Database (Denmark)

Falch, Morten

2008-01-01

Broadband is seen as a key infrastructure for developing the information society. For this reason many Governments are actively engaged in stimulating investments in broadband infrastructures and use of broadband services. This chapter compares a wide range of broadband strategies in the most suc....... Many countries have provided active support for stimulating diffusion of broadband and national variants of this type of policies in different countries are important for an explanation of national differences in adoption of broadband....

Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

CERN Document Server

Rossini, Lorenzo; The ATLAS collaboration

2018-01-01

Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High- Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of 10^15 neq/cm2 and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time and considers both planar and 3D sensor designs. In addition to thoroughly describing the setup, we compare predictions for basic...

A Design of 45-Degree Dual-Polarization Broadband Plane Station Antenna

Directory of Open Access Journals (Sweden)

Jianming Zhou

2015-01-01

Full Text Available A new broadband planar dual-polarization base station antenna is proposed, the antenna consists of two broadband plane coplanar base station antenna units, and so it has features of plane antenna. Two broadband plane station antenna units can, respectively, form double polarization in the direction. We analyzed the relative positions between the two antenna units and their effects on the performances of the antenna, especially for the influence of isolation. Broadband antenna has the characteristics of the broadband station antenna, and bandwidth is also guaranteed. The measured results show that the antenna can obtain 45% relative bandwidth, and 30 dB isolation degree also can be got, and the radiation performance is also good. Measurement results confirmed that the antenna gain can be guaranteed among 48% relative bandwidth, 15 dB of gain is got among bandwidth of 1.69–2.78 GHz, the isolation degree of different polarization method can reach 30 dB, and the measurement gain of two polarization methods of antenna both can reach 8.5 dBi.

Parameterization models for solar radiation and solar technology applications

Energy Technology Data Exchange (ETDEWEB)

Khalil, Samy A. [National Research Institute of Astronomy and Geophysics, Solar and Space Department, Marsed Street, Helwan, 11421 Cairo (Egypt)

2008-08-15

Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined. (author)

Parameterization models for solar radiation and solar technology applications

International Nuclear Information System (INIS)

Khalil, Samy A.

2008-01-01

Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined

Applications of the energy differentiation type radiation line sensor to such as inspection for the plumbing corrosion

International Nuclear Information System (INIS)

Tomita, Yasuhiro; Shirayanagi, Yuji; Matsui, Shinjiro; Kamiya, Yosuke; Kobayashi, Akira

2015-01-01

The authors have engaged in development of the next-generation radiation detectors that can give information on energy such as X-rays and γ-rays, and commercialized an energy discrimination type radiation line sensor capable of discriminating the energy of photons using a CdTe radiation detector element. This paper introduces the structure and principles of this energy discrimination type radiation line sensor. As the basic application, it also introduces the material identification, energy discrimination type X-ray CT imaging, and the quantitative determination of iron plate thickness using X-ray. In addition, it introduces the radiation line sensor we have developed for inspecting the reduced amount of wall thickness of piping with insulation materials. This radiation line sensor for pipe thinning inspection combined with radiation sources (X-rays, γ-rays) and a transport system is capable of accurately and efficiently inspecting reduced wall thickness, while moving the censor on the covered pipe with heat insulating materials through remote control, without removing piping insulation materials and without stopping the use of piping. (A.O.)

Evaluation of the Detection Efficiency of LYSO Scintillator in the Fiber-Optic Radiation Sensor

Directory of Open Access Journals (Sweden)

Chan Hee Park

2014-01-01

Full Text Available The aim of this study was to develop and evaluate fiber-optic sensors for the remote detection of gamma rays in areas that are difficult to access, such as a spent fuel pool. The fiber-optic sensor consists of a light-generating probe, such as scintillators for radiation detection, plastic optical fibers, and light-measuring devices, such as PMT. The (Lu,Y2SiO5:Ce(LYSO:Ce scintillator was chosen as the light-generating probe. The (Lu,Y2SiO5:Ce(LYSO:Ce scintillator has higher scintillation efficiency than the others and transmits light well through an optical fiber because its refraction index is similar to the refractive index of the optical fiber. The fiber-optic radiation sensor using the (Lu,Y2SiO5:Ce(LYSO:Ce scintillator was evaluated in terms of the detection efficiency and reproducibility for examining its applicability as a radiation sensor.

Estimate of the atmospheric turbidity from three broad-band solar radiation algorithms. A comparative study

Directory of Open Access Journals (Sweden)

G. López

2004-09-01

Full Text Available Atmospheric turbidity is an important parameter for assessing the air pollution in local areas, as well as being the main parameter controlling the attenuation of solar radiation reaching the Earth's surface under cloudless sky conditions. Among the different turbidity indices, the Ångström turbidity coefficient β is frequently used. In this work, we analyse the performance of three methods based on broad-band solar irradiance measurements in the estimation of β. The evaluation of the performance of the models was undertaken by graphical and statistical (root mean square errors and mean bias errors means. The data sets used in this study comprise measurements of broad-band solar irradiance obtained at eight radiometric stations and aerosol optical thickness measurements obtained at one co-located radiometric station. Since all three methods require estimates of precipitable water content, three common methods for calculating atmospheric precipitable water content from surface air temperature and relative humidity are evaluated. Results show that these methods exhibit significant differences for low values of precipitable water. The effect of these differences in precipitable water estimates on turbidity algorithms is discussed. Differences in hourly turbidity estimates are later examined. The effects of random errors in pyranometer measurements and cloud interferences on the performance of the models are also presented. Examination of the annual cycle of monthly mean values of β for each location has shown that all three turbidity algorithms are suitable for analysing long-term trends and seasonal patterns.

Estimate of the atmospheric turbidity from three broad-band solar radiation algorithms. A comparative study

Directory of Open Access Journals (Sweden)

G. López

2004-09-01

Full Text Available Atmospheric turbidity is an important parameter for assessing the air pollution in local areas, as well as being the main parameter controlling the attenuation of solar radiation reaching the Earth's surface under cloudless sky conditions. Among the different turbidity indices, the Ångström turbidity coefficient β is frequently used. In this work, we analyse the performance of three methods based on broad-band solar irradiance measurements in the estimation of β. The evaluation of the performance of the models was undertaken by graphical and statistical (root mean square errors and mean bias errors means. The data sets used in this study comprise measurements of broad-band solar irradiance obtained at eight radiometric stations and aerosol optical thickness measurements obtained at one co-located radiometric station. Since all three methods require estimates of precipitable water content, three common methods for calculating atmospheric precipitable water content from surface air temperature and relative humidity are evaluated. Results show that these methods exhibit significant differences for low values of precipitable water. The effect of these differences in precipitable water estimates on turbidity algorithms is discussed. Differences in hourly turbidity estimates are later examined. The effects of random errors in pyranometer measurements and cloud interferences on the performance of the models are also presented. Examination of the annual cycle of monthly mean values of β for each location has shown that all three turbidity algorithms are suitable for analysing long-term trends and seasonal patterns.

Estimate of the atmospheric turbidity from three broad-band solar radiation algorithms. A comparative study

Energy Technology Data Exchange (ETDEWEB)

Lopez, G.; Batlles, F.J. [Dept. de Ingenieria Electrica y Termica, EPS La Rabida, Univ. de Huelva, Huelva (Spain)

2004-07-01

Atmospheric turbidity is an important parameter for assessing the air pollution in local areas, as well as being the main parameter controlling the attenuation of solar radiation reaching the Earth's surface under cloudless sky conditions. Among the different turbidity indices, the Aangstroem turbidity coefficient {beta} is frequently used. In this work, we analyse the performance of three methods based on broadband solar irradiance measurements in the estimation of {beta}. The evaluation of the performance of the models was undertaken by graphical and statistical (root mean square errors and mean bias errors) means. The data sets used in this study comprise measurements of broad-band solar irradiance obtained at eight radiometric stations and aerosol optical thickness measurements obtained at one co-located radiometric station. Since all three methods require estimates of precipitable water content, three common methods for calculating atmospheric precipitable water content from surface air temperature and relative humidity are evaluated. Results show that these methods exhibit significant differences for low values of precipitable water. The effect of these differences in precipitable water estimates on turbidity algorithms is discussed. Differences in hourly turbidity estimates are later examined. The effects of random errors in pyranometer measurements and cloud interferences on the performance of the models are also presented. Examination of the annual cycle of monthly mean values of {beta} for each location has shown that all three turbidity algorithms are suitable for analysing long-term trends and seasonal patterns. (orig.)

Broadband enhancement of infrared absorption in microbolometers using Ag nanocrystals

International Nuclear Information System (INIS)

Hyun, Jerome K.; Ahn, Chi Won; Kim, Woo Choong; Kim, Tae Hyun; Hyun, Moon Seop; Kim, Hee Yeoun; Park, Jae Hong; Lee, Won-Oh

2015-01-01

High performance microbolometers are widely sought for thermal imaging applications. In order to increase the performance limits of microbolometers, the responsivity of the device to broadband infrared (IR) radiation needs to be improved. In this work, we report a simple, quick, and cost-effective approach to modestly enhance the broadband IR response of the device by evaporating Ag nanocrystals onto the light entrance surface of the device. When irradiated with IR light, strong fields are built up within the gaps between adjacent Ag nanocrystals. These fields resistively generate heat in the nanocrystals and underlying substrate, which is transduced into an electrical signal via a resistive sensing element in the device. Through this method, we are able to enhance the IR absorption over a broadband spectrum and improve the responsivity of the device by ∼11%

RD50 recent results: Development of radiation hard sensors for SLHC

CERN Document Server

Macchiolo, Anna

2009-01-01

The need for radiation hard semiconductor detectors for the tracker regions in high energy physics experiments at a future high luminosity hadron collider, like the proposed LHC upgrade, has led to the formation of the CERN RD50 collaboration. The R&D directions of RD50 follow two paths: the optimization of radiation hard bulk materials (Material Engineering) and the development of new detector designs (Device Engineering) as 3D sensors, thin sensors and n-in-p sensors. Some of the RD50 most recent results about silicon detectors are reported in this paper, with special reference to: (i) identification of defects responsible for long term annealing, (ii) charge collection efficiency of irradiated planar devices, in particular n-in-p microstrip detectors and epitaxial diodes, (iii) charge collection efficiency of double-type column 3D detectors, (iv) comparison of the performances of FZ and MCZ structures under mixed irradiation.

2-D FEM Simulation of Propagation and Radiation of Leaky Lamb Wave in a Plate-Type Ultrasonic Waveguide Sensor

Energy Technology Data Exchange (ETDEWEB)

Park, Sang-Jin; Kim, Hoe-Woong; Joo, Young-Sang; Kim, Sung-Kyun; Kim, Jong-Bum [KAERI, Daejeon (Korea, Republic of)

2016-05-15

This paper introduces the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted for the radiation beam profile analysis. The FEM simulations are performed with three different excitation frequencies and the radiation beam profiles obtained from FEM simulations are compared with those obtained from corresponding experiments. This paper deals with the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted to analyze the radiation beam profiles. The radiation beam profile results obtained from the FEM simulation show good agreement with the ones obtained from the experiment. This result will be utilized to improve the performance of the developed waveguide sensor. The quality of the visualized image is mainly affected by beam profile characteristics of the leaky wave radiated from the waveguide sensor. However, the relationships between the radiation beam profile and many parameters of the waveguide sensor are not fully revealed yet. Therefore, further parametric studies are necessary to improve the performance of the sensor and the finite element method (FEM) is one of the most effective tools for the parametric study.

Highly Reflecting, Broadband Deformable Membrane Mirror for Wavefront Control Applications, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This Phase I STTR project will develop a highly reflecting, broadband, radiation resistant, low-stress and lightweight, membrane integrated into an electrostatically...

Study of planar pixel sensors hardener to radiations for the upgrade of the ATLAS vertex detector

International Nuclear Information System (INIS)

Benoit, M.

2011-05-01

In this work, we present a study, using TCAD (Technology Computer-Assisted Design) simulation, of the possible methods of designing planar pixel sensors by reducing their inactive area and improving their radiation hardness for use in the Insertable B-Layer (IBL) project and for SLHC upgrade phase for the ATLAS experiment. Different physical models available have been studied to develop a coherent model of radiation damage in silicon that can be used to predict silicon pixel sensor behavior after exposure to radiation. The Multi-Guard Ring Structure, a protection structure used in pixel sensor design was studied to obtain guidelines for the reduction of inactive edges detrimental to detector operation while keeping a good sensor behavior through its lifetime in the ATLAS detector. A campaign of measurement of the sensor process parameters and electrical behavior to validate and calibrate the TCAD simulation models and results are also presented. A model for diode charge collection in highly irradiated environment was developed to explain the high charge collection observed in highly irradiated devices. A simple planar pixel sensor digitization model to be used in test beam and full detector system is detailed. It allows for easy comparison between experimental data and prediction by the various radiation damage models available. The digitizer has been validated using test beam data for unirradiated sensors and can be used to produce the first full scale simulation of the ATLAS detector with the IBL that include sensor effects such as slim edge and thinning of the sensor. (author)

Broadband Seismometer at 2500m Depth in the Mediterranean Sea

Science.gov (United States)

Deschamps, A.; Hello, Y.; Charvis, P.; Dugué, M.; Bertin, V.; Valdy, P.; Le van Suu, A.; Real, D.

2003-04-01

In the frame of the ANTARES project, devoted to solar neutrinos detection across a large (0.1 km3) water volume located in deep sea, sea bottom facilities were developed at a depth of 2500m. Power supply, instrumentation control and data transmission have been implemented offshore Toulon (France) through a 43km long marine cable. A broadband seismological sensor has been installed among the instrumentation to control of physical and chemical environment of the neutrino detectors. The instrument was designed by Guralp Systems on the basis of CMG-3T seismometer (band-pass 120s-50hz) connected to a CMG DM24 digitizer for mechanical control and signal digitisation. Seismometer was inserted in titanium housing which fulfil the safety requirements of deployment operation. Control of CMG DM24 through asynchronous RS232 serial line was implemented in the ANTARES acquisition software running on the sea bottom. An interface running at the surface allows control and storage of the data. In January, the sensor was launched with the ANTARES instrumental line. In a second step the sensor has been slightly moved away from the ANTARES structure (60m), partly buried in the ground, roughly levelled and oriented by the IFREMER submarine Nautile. During the same operation the instrumentation line was connected to the power supply and data acquisition control. Masses of the seismometer were unlocked from the surface. Data are now continuously collected from Toulon and transmitted to Geosciences Azur in quasi real time. After a test period of 3 months, the sensor should be recovered for upgrades. For the final deployment (10 years), the ANTARES time control signal should be used to synchronise the sensor internal clock. This is the first real time broadband seismometer deployed in Europe and it will increase, in the future, our capability of marine earthquake detection in the area.

Adaptive Multichannel Radiation Sensors for Plant Parameter Monitoring

Science.gov (United States)

Mollenhauer, Hannes; Remmler, Paul; Schuhmann, Gudrun; Lausch, Angela; Merbach, Ines; Assing, Martin; Mollenhauer, Olaf; Dietrich, Peter; Bumberger, Jan

2016-04-01

Nutrients such as nitrogen are playing a key role in the plant life cycle. They are much needed for chlorophyll production and other plant cell components. Therefore, the crop yield is strongly affected by plant nutrient status. Due to the spatial and temporal variability of soil characteristics or swaying agricultural inputs the plant development varies within a field. Thus, the determination of these fluctuations in the plant development is valuable for a detection of stress conditions and optimization of fertilisation due to its high environmental and economic impact. Plant parameters play crucial roles in plant growth estimation and prediction since they are used as indicators of plant performance. Especially indices derived out of remote sensing techniques provide quantitative information about agricultural crops instantaneously, and above all, non-destructively. Due to the specific absorption of certain plant pigments, a characteristic spectral signature can be seen in the visible and IR part of the electromagnetic spectrum, known as narrow-band peaks. In an analogous manner, the presence and concentration of different nutrients cause a characteristic spectral signature. To this end, an adequate remote sensing monitoring concept is needed, considering heterogeneity and dynamic of the plant population and economical aspects. This work will present the development and field investigations of an inexpensive multichannel radiation sensor to observe the incoming and reflected specific parts or rather distinct wavelengths of the solar light spectrum on the crop and facilitate the determination of different plant indices. Based on the selected sensor wavelengths, the sensing device allows the detection of specific parameters, e.g. plant vitality, chlorophyll content or nitrogen content. Besides the improvement of the sensor characteristic, the simple wavelength adaption, and the price-performance ratio, the achievement of appropriate energy efficiency as well as a

Measurement of radiation induced transients in hybrid microcircuits by magnetic thin film sensor/recorders

International Nuclear Information System (INIS)

Hsieh, E.J.; Vindelov, K.E.; Brown, T.G.; Miller, D.E.

1976-01-01

Magnetic thin film transient current sensor/recorders were modified to make two types of nuclear test measurements, transient currents in hybrid microcircuits and internal electromagnetic pulse (IEMP) fields. The measurements were made possible by the invention of split-domain sensor/recorders which can measure bilateral currents and can be reset and readout on location. The sensor/recorders were used in two underground nuclear tests and numerous calibration tests in radiation-simulation machines. The data showed that the nuclear environment had negligible effect on the sensor/recorder's operation and the recorded informations on the sensor/recorders were the signals intended to be monitored. Also, the experimental data agreed with the theoretical analysis in controlled experiments. The data were examined first by on location readout with a magnetic tape viewer and later by Kerr magneto-optic readout in the laboratory. To translate the data into current readings, we reconstructed facsimile data (on each of the sensor/recorders) in the laboratory by current pulses with the same pulse width as the radiation event. An additional check on the accuracy of the data was made by using both the sensor/recorder and the conventional pickup-oscilloscope-camera technique to monitor the same current lead in a simulated radiation environment. Over five runs were made, and the agreement among the two measurement methods was within 25%. The data collectively implied that the measurements were reliable and dependable

Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

CERN Document Server

Rossini, Lorenzo; The ATLAS collaboration

2018-01-01

Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of 10^15 neq/cm^2 and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current and future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time and considers both planar and 3D sensor designs. In addition to thoroughly describing the setup, we compare predictions for b...

Broadband asymmetric transmission of linearly polarized electromagnetic waves based on chiral metamaterial

Science.gov (United States)

Stephen, Lincy; Yogesh, N.; Subramanian, V.

2018-01-01

The giant optical activity of chiral metamaterials (CMMs) holds great potential for tailoring the polarization state of an electromagnetic (EM) wave. In controlling the polarization state, the aspect of asymmetric transmission (AT), where a medium allows the EM radiation to pass through in one direction while restricting it in the opposite direction, adds additional degrees of freedom such as one-way channelling functionality. In this work, a CMM formed by a pair of mutually twisted slanted complementary metal strips is realized for broadband AT accompanied with cross-polarization (CP) conversion for linearly polarized EM waves. Numerically, the proposed ultra-thin (˜λ/42) CMM shows broadband AT from 8.58 GHz to 9.73 GHz (bandwidth of 1.15 GHz) accompanied with CP transmission magnitude greater than 0.9. The transmission and reflection spectra reveal the origin of the asymmetric transmission as the direction sensitive cross polarization conversion and anisotropic electric coupling occurring in the structure which is then elaborated with the surface current analysis and electric field distribution within the structure. An experiment is carried out to verify the broadband AT based CP conversion of the proposed CMM at microwave frequencies, and a reliable agreement between numerical and experimental results is obtained. Being ultra-thin, the reported broadband AT based CP conversion of the proposed CMM is useful for controlling radiation patterns in non-reciprocal EM devices and communication networks.

Biobased Nanoparticles for Broadband UV Protection with Photostabilized UV Filters

NARCIS (Netherlands)

Hayden, D.R.|info:eu-repo/dai/nl/412640694; Imhof, A.|info:eu-repo/dai/nl/145641600; Velikov, K. P.|info:eu-repo/dai/nl/239483472

2016-01-01

Sunscreens rely on multiple compounds to provide effective and safe protection against UV radiation. UV filters in sunscreens, in particular, provide broadband UV protection but are heavily linked to adverse health effects due to the generation of carcinogenic skin-damaging reactive oxygen species

Broadband terahertz wave deflection based on C-shape complex metamaterials with phase discontinuities

KAUST Repository

Zhang, Xueqian; Tian, Zhen; Yue, Weisheng; Gu, Jianqiang; Zhang, Shuang; Han, Jiaguang; Zhang, Weili

2013-01-01

A broadband terahertz wave deflector based on metasurface induced phase discontinuities is reported. Various frequency components ranging from 0.43 to 1.0 THz with polarization orthogonal to the incidence are deflected into a broad range of angles from 25° to 84°. A Fresnel zone plate consequently developed from the beam deflector is capable of focusing a broadband terahertz radiation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Broadband terahertz wave deflection based on C-shape complex metamaterials with phase discontinuities

KAUST Repository

Zhang, Xueqian

2013-06-21

A broadband terahertz wave deflector based on metasurface induced phase discontinuities is reported. Various frequency components ranging from 0.43 to 1.0 THz with polarization orthogonal to the incidence are deflected into a broad range of angles from 25° to 84°. A Fresnel zone plate consequently developed from the beam deflector is capable of focusing a broadband terahertz radiation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A MGy radiation-hardened sensor instrumentation link for nuclear reactor monitoring and remote handling

Energy Technology Data Exchange (ETDEWEB)

Verbeeck, Jens; Cao, Ying [KU Leuven - KUL, Div. LRD-MAGyICS, Kasteelpark Arenberg 10, 3001 Heverlee (Belgium); Van Uffelen, Marco; Mont Casellas, Laura; Damiani, Carlo; Morales, Emilio Ruiz; Santana, Roberto Ranz [Fusion for Energy - F4E, c/Josep,n deg. 2, Torres Diagonal Litoral, Ed. B3, 08019 Barcelona (Spain); Meek, Richard; Haist, Bernhard [Oxford Technologies Ltd. OTL, 7 Nuffield Way, Abingdon OX14 1RL (United Kingdom); De Cock, Wouter; Vermeeren, Ludo [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Steyaert, Michiel [KU Leuven, ESAT-MICAS, KasteelparkArenberg 10, 3001 Heverlee (Belgium); Leroux, Paul [KU Leuven, ESAT-MICAS, KasteelparkArenberg 10, 3001 Heverlee (Belgium)

2015-07-01

Decommissioning, dismantling and remote handling applications in nuclear facilities all require robotic solutions that are able to survive in radiation environments. Recently raised safety, radiation hardness and cost efficiency demands from both the nuclear regulatory and the society impose severe challenges in traditional methods. For example, in case of the dismantling of the Fukushima sites, solutions that survive accumulated doses higher than 1 MGy are mandatory. To allow remote operation of these tools in nuclear environments, electronics were used to be shielded with several centimeters of lead or even completely banned in these solutions. However, shielding electronics always leads to bulky and heavy solutions, which reduces the flexibility of robotic tools. It also requires longer repair time and produces extra waste further in a dismantling or decommissioning cycle. In addition, often in current reactor designs, due to size restrictions and the need to inspect very tight areas there are limitations to the use of shielding. A MGy radiation-hardened sensor instrumentation link developed by MAGyICS provides a solution to build a flexible, easy removable and small I and C module with MGy radiation tolerance without any shielding. Hereby it removes all these pains to implement electronics in robotic tools. The demonstrated solution in this poster is developed for ITER Remote Handling equipments operating in high radiation environments (>1 MGy) in and around the Tokamak. In order to obtain adequately accurate instrumentation and control information, as well as to ease the umbilical management, there is a need of front-end electronics that will have to be located close to those actuators and sensors on the remote handling tool. In particular, for diverter remote handling, it is estimated that these components will face gamma radiation up to 300 Gy/h (in-vessel) and a total dose of 1 MGy. The radiation-hardened sensor instrumentation link presented here, consists

Guidelines for Standardized Testing of Broadband Seismometers and Accelerometers

Science.gov (United States)

Hutt, Charles R.; Evans, John R.; Followill, Fred; Nigbor, Robert L.; Wielandt, Erhard

2010-01-01

Testing and specification of seismic and earthquake-engineering sensors and recorders has been marked by significant variations in procedures and selected parameters. These variations cause difficulty in comparing such specifications and test results. In July 1989, and again in May 2005, the U.S. Geological Survey hosted international pub-lic/private workshops with the goal of defining widely accepted guidelines for the testing of seismological inertial sensors, seismometers, and accelerometers. The Proceedings of the 2005 workshop have been published and include as appendix 6 the report of the 1989 workshop. This document represents a collation and rationalization of a single set of formal guidelines for testing and specifying broadband seismometers and accelerometers.

A hybrid optical system for broadband imaging in guidance and control

Science.gov (United States)

Wu, Xiaofang; Jiang, Yuesong; Shen, Chunyan; Zhao, Yiming

2006-11-01

A binary optics method has been adopted to improve upon a conventional optical system in guidance and control, and a hybrid broadband imaging system that includes a binary surface is analyzed and evaluated by optical design software ZEMAX. The practical design shows that the introduction of binary optics can simplify the structure of the imaging system and reduce the size and weight of the broadband guidance and control system. Moreover, it can help to acquire images of radiation of different wavelengths from targets; hence it will result in improved overall performance of missiles in wars.

Characterisation and application of radiation hard sensors for LHC and ILC

International Nuclear Information System (INIS)

Novgorodova, Olga

2013-11-01

The Large Hadron Collider (LHC) currently in operation intends to explore particle physics on the TeV scale. The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are being designed to measure the properties of particles discovered at the LHC with higher precision. Very forward detector systems at these machines are needed for the precise measurement of the luminosity and to approach full polar angle overage. In the current detector concepts for linear collider two electromagnetic calorimeters, Beam Calorimeter (BeamCal) and Luminosity Calorimeter (LumiCal), are foreseen. Both calorimeters are designed as sandwich calorimeters with tungsten absorber layers instrumented with finely segmented sensors. Due to a large amount of beamstrahlung remnants hitting BeamCal at the innermost radii, the sensors must withstand up to 1 MGy radiation dose per year. In this thesis two types of sensor materials were investigated: single crystal chemical vapour deposition diamonds (scCVDD) and gallium arsenide doped by chromium (GaAs:Cr). The very forward calorimeters ensure coverage for high energy electrons, positrons and photons down to very low polar angles. Within this thesis, simulation studies are presented for different beam parameters of the ILC. A new sensor segmentation was proposed to achieve better reconstruction efficiency of single high-energy electrons, positrons and photons on top of the beamstrahlung background. Only for a few years ago polycrystalline diamond sensors have been used for beam diagnostics in high-energy physics experiments. The Compact Muon Solenoid experiment, CMS, at the LHC is instrumented with several detectors for the Beam Conditions and Radiation Monitoring. The Fast Beam Conditions Monitor (BCM1F) is part of these systems. Here for the first time single crystal diamond sensors have been used. Eight detectors, comprising each a single crystal sensor and front-end electronics, are positioned around the beam pipe on both

Characterisation and application of radiation hard sensors for LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Novgorodova, Olga

2013-11-15

The Large Hadron Collider (LHC) currently in operation intends to explore particle physics on the TeV scale. The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are being designed to measure the properties of particles discovered at the LHC with higher precision. Very forward detector systems at these machines are needed for the precise measurement of the luminosity and to approach full polar angle overage. In the current detector concepts for linear collider two electromagnetic calorimeters, Beam Calorimeter (BeamCal) and Luminosity Calorimeter (LumiCal), are foreseen. Both calorimeters are designed as sandwich calorimeters with tungsten absorber layers instrumented with finely segmented sensors. Due to a large amount of beamstrahlung remnants hitting BeamCal at the innermost radii, the sensors must withstand up to 1 MGy radiation dose per year. In this thesis two types of sensor materials were investigated: single crystal chemical vapour deposition diamonds (scCVDD) and gallium arsenide doped by chromium (GaAs:Cr). The very forward calorimeters ensure coverage for high energy electrons, positrons and photons down to very low polar angles. Within this thesis, simulation studies are presented for different beam parameters of the ILC. A new sensor segmentation was proposed to achieve better reconstruction efficiency of single high-energy electrons, positrons and photons on top of the beamstrahlung background. Only for a few years ago polycrystalline diamond sensors have been used for beam diagnostics in high-energy physics experiments. The Compact Muon Solenoid experiment, CMS, at the LHC is instrumented with several detectors for the Beam Conditions and Radiation Monitoring. The Fast Beam Conditions Monitor (BCM1F) is part of these systems. Here for the first time single crystal diamond sensors have been used. Eight detectors, comprising each a single crystal sensor and front-end electronics, are positioned around the beam pipe on both

\\title{Development of Radiation Damage Models for Irradiated Silicon Sensors Using TCAD Tools}

CERN Document Server

Bhardwaj, Ashutosh; Lalwani, Kavita; Ranjan, Kirti; Printz, Martin; Ranjeet, Ranjeet; Eber, Robert; Eichhorn, Thomas; Peltola, Timo Hannu Tapani

2014-01-01

Abstract. During the high luminosity upgrade of the LHC (HL-LHC) the CMS tracking system will face a more intense radiation environment than the present system was designed for. In order to design radiation tolerant silicon sensors for the future CMS tracker upgrade it is fundamental to complement the measurement with device simulation. This will help in both the understanding of the device performance and in the optimization of the design parameters. One of the important ingredients of the device simulation is to develop a radiation damage model incorporating both bulk and surface damage. In this paper we will discuss the development of a radiation damage model by using commercial TCAD packages (Silvaco and Synopsys), which successfully reproduce the recent measurements like leakage current, depletion voltage, interstrip capacitance and interstrip resistance, and provides an insight into the performance of irradiated silicon strip sensors.

Design of Zigbee-Based Wireless Sensor suitable for Radiation Detection and Monitoring

International Nuclear Information System (INIS)

Madian, A.A.

2012-01-01

This paper presents a design for a wireless sensor nuclear radiation monitoring and detection based on Zigbee. The system consists of transmitter and receiver modules. The wireless sensor installed at transmitter whiles the receiver processing data. The communication between Tx and Rx done through Zigbee module using the protocol of CSMA/CA. The Zigbee has the advantages of reliable, power-efficient, and low-latency communications between low-cost Tx/Rx.The wireless sensor implementation can easily be deployed to discover unusual or abnormal radioactivity. The sensors are convenient to be installed indoors or outdoors, as well as to be mounted on mobile equipment's. All wireless nuclear detection sensors are designed using micro controller and other integrated systems

Comparison of VP broadband tiltmeter and VS vertical pendulum tiltmeter

OpenAIRE

Ma, Wugang; Wu, Yanxia; Zhao, Huiqin

2015-01-01

Vertical pendulum (VP) tiltmeter is a kind of earthquake precursor observation equipment, which is used to record the interaction force associated with astronomical tidal tilts caused. Currently, VP broadband tiltmeter and vertical sensor (VS) vertical pendulum tiltmeter are primarily used. In this paper, we compare the two different instruments by using four aspects—mechanical structure, circuitry, zeroing, and bandwidth—based on their working principles and applications. We conclude that VP...

Silicon sensor probing and radiation studies for the LHCb silicon tracker

International Nuclear Information System (INIS)

Lois, Cristina

2006-01-01

The LHCb Silicon Tracker (ST) will be built using silicon micro-strip technology. A total of 1400 sensors, with strip pitches of approximately 200μm and three different substrate thicknesses, will be used to cover the sensitive area with readout strips up to 38cm in length. We present the quality assurance program followed by the ST group together with the results obtained for the first batches of sensors from the main production. In addition, we report on an investigation of the radiation hardness of the sensors. Prototype sensors were irradiated with 24GeV/c protons up to fluences equivalent to 20 years of LHCb operation. The damage coefficient for the leakage current was studied, and full depletion voltages were determined

Development of radiation hard CMOS active pixel sensors for HL-LHC

International Nuclear Information System (INIS)

Pernegger, Heinz

2016-01-01

New pixel detectors, based on commercial high voltage and/or high resistivity full CMOS processes, hold promise as next-generation active pixel sensors for inner and intermediate layers of the upgraded ATLAS tracker. The use of commercial CMOS processes allow cost-effective detector construction and simpler hybridisation techniques. The paper gives an overview of the results obtained on AMS-produced CMOS sensors coupled to the ATLAS Pixel FE-I4 readout chips. The SOI (silicon-on-insulator) produced sensors by XFAB hold great promise as radiation hard SOI-CMOS sensors due to their combination of partially depleted SOI transistors reducing back-gate effects. The test results include pre-/post-irradiation comparison, measurements of charge collection regions as well as test beam results.

An improved broadband E patch microstrip antenna for wireless communications

Science.gov (United States)

Bzeih, Amer; Chahine, Soubhi Abou; Kabalan, Karim Y.; El-Hajj, Ali; Chehab, Ali

2007-12-01

A broadband probe-fed microstrip antenna with E-shaped patch on a single-layer air substrate is investigated. Bandwidth enhancement of the antenna is achieved by inserting two parallel slots into its radiating patch. The effects of the antenna parameters are analyzed, and their optimal values for broadband operation are obtained. The design parameters are formulated as a function of the center frequency, and the empirical equations are validated by simulation. A 51.5% enhanced E patch antenna for modern wireless communications (Personal Communications Service, Digital Cellular System, Universal Mobile Telecommunications System, Wireless Local Area Network 802.11 b/g, and Bluetooth) is designed, simulated, fabricated, and measured. A comparison between simulated and measured results is presented, and it showed satisfactory agreement. Moreover, the effect of incorporating more parallel slots into the radiating patch is investigated. The antenna is designed and simulated for different scenarios (four slots, six slots, and eight slots), where a bandwidth of 57% is achieved in the eight-slot design.

X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra

International Nuclear Information System (INIS)

Ostorero, L.; Moderski, R.; Stawarz, L.; Diaferio, A.; Kowalska, I.; Cheung, C.C.; Kataoka, J.; Begelman, M.C.; Wagner, S.J.

2010-01-01

In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the GPS spectral energy distribution (SED) with the source expansion, predicting significant and complex high-energy emission, from the X-ray to the γ-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N H ) and radio (N HI ) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.

An enhanced ionising radiation monitoring and detecting technique in radiotherapy units of hospitals using wireless sensor networks

International Nuclear Information System (INIS)

Ali, Peter

2017-01-01

In this paper, a solution of ionising radiation monitoring based on the concept of Wireless Sensor Network (WSN), is presented. Radiation dose rate measured by the sensor node is sent to the monitoring station through ZigBee wireless network operated on 2.4 GHz unlicensed Industrial Scientific Medical (ISM) band. The system is calibrated for use for ionizing radiation dose rate range of between amount of ionising radiation observed in radiotherapy unit of a hospital and 1.02 mSv/h. Power consumption of the sensor node is kept low by operating the node ZigBee radio with low duty cycle: i.e. by keeping the radio awake only during data transmission/reception. Two ATmega8 microcontrollers, one each for sensor node and the monitoring station, are programmed to perform interfacing, data processing, and control functions. The system range of coverage is 124m for outdoor (line of site) deployment and 56.8m for indoor application where 5 brick walls separated the sensor node and the monitoring station. Range of coverage of the system is extendable via the use of ZigBee router (s)

Metamaterial-based half Maxwell fish-eye lens for broadband directive emissions

Science.gov (United States)

Dhouibi, Abdallah; Nawaz Burokur, Shah; de Lustrac, André; Priou, Alain

2013-01-01

The broadband directive emission from a metamaterial surface is numerically and experimentally reported. The metasurface, composed of non-resonant complementary closed ring structures, is designed to obey the refractive index of a half Maxwell fish-eye lens. A planar microstrip Vivaldi antenna is used as transverse magnetic polarized wave launcher for the lens. A prototype of the lens associated with its feed structure has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Measurements agree quantitatively and qualitatively with theoretical simulations.

Enhancement of ZnO-rGO nanocomposite thin films by gamma radiation for E. coli sensor

Energy Technology Data Exchange (ETDEWEB)

Noor Azmy, Noor Azwen [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Bakar, Ahmad Ashrif A., E-mail: ashrif@ukm.edu.my [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Arsad, Norhana [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Idris, Sarada [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Radiation Facilities Division, Block 42, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Mohmad, Abdul Rahman [MEMS-NEMS and Nanoelectronics, Institute of Microengineering and Nanoelectronics (IMEN), 43650 UKM, Bangi, Selangor (Malaysia); Abdul Hamid, Aidil [School of Biosciences and Biotechnology, Faculty of Science and Technology, 43650 UKM, Bangi, Selangor (Malaysia)

2017-01-15

Highlights: • ZnO-rGO nanocomposite thin films by gamma radiation for E. coli sensor were fabricated for the first time. • Exposed to gamma radiation leads to the change the microstructure of the films. • The optical behaviors of thin films were found to be gamma dose dependent. • The sensors had a linear response with GO concentration. • The sensors exhibited enhanced sensitivity at higher gamma radiation. - Abstract: The fabricated E. coli sensor of ZnO-rGO nanocomposite thin films by gamma radiation was investigated. Nanocomposite films were prepared via sol–gel method and were irradiated at 10 kGy at room temperature. The surface characteristic of as-prepared samples have been characterized by x-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The proposed structure shows that exposed gamma radiation may change the microstructure of the films occurs as a result of their flexible structure. Uv–vis spectra of nanocomposite were studied to investigate the optical behavior of ZnO-rGO films and the optical energy band gap and Urbach energy were found to be gamma dose dependent. The sensing properties were identified by measuring the changes of conductivity of film using I-V measurement. Upon exposure to E. coli, the radiated ZnO-rGO films (1.00 vol% GO) exhibited higher sensitivity, as much as 4.62 × 10{sup −3}, than un-radiated films, 1.04 × 10{sup −3}. This enhancement of the I-V response was attributed to a positive influence of the gamma radiation in these films. The results prove that our ZnO-rGO nanocomposites thin films by gamma radiation demonstrate a strong performance for the detection of microbiological organisms in water.

Impact of cyclostationarity on fan broadband noise prediction

Science.gov (United States)

Wohlbrandt, A.; Kissner, C.; Guérin, S.

2018-04-01

One of the dominant noise sources of modern Ultra High Bypass Ratio (UHBR) engines is the interaction of the rotor wakes with the leading edges of the stator vanes in the fan stage. While the tonal components of this noise generation mechanism are fairly well understood by now, the broadband components are not. This calls to further the understanding of the broadband noise generation in the fan stage. This article introduces a new extension to the Random Particle Mesh (RPM) method, which accommodates in-depth studies of the impact of cyclostationary wake characteristics on the broadband noise in the fan stage. The RPM method is used to synthesize a turbulence field in the stator domain using a URANS simulation characterized by time-periodic turbulence and mean flow. The rotor-stator interaction noise is predicted by a two-dimensional CAA computation of the stator cascade. The impact of cyclostationarity is decomposed into various effects, which are separately investigated. This leads to the finding that the periodic turbulent kinetic energy (TKE) and periodic flow have only a negligible effect on the radiated sound power. The impact of the periodic integral length scale (TLS) is, however, substantial. The limits of a stationary representation of the TLS are demonstrated making this new extension to the RPM method indispensable when background and wake TKE are of comparable level. Good agreement of the predictions with measurements obtained from the 2015 AIAA Fan Broadband Noise Prediction Workshop are also shown.

Solar radiation modeling and measurements for renewable energy applications: data and model quality

International Nuclear Information System (INIS)

Myers, Daryl R.

2005-01-01

Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data

Solar radiation modeling and measurements for renewable energy applications: data and model quality

Energy Technology Data Exchange (ETDEWEB)

Myers, D.R. [National Renewable Energy Laboratory, Golden, CO (United States)

2005-07-01

Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data. (author)

Broad-band near-field ground motion simulations in 3-dimensional scattering media

KAUST Repository

Imperatori, W.; Mai, Paul Martin

2012-01-01

examine scattering phenomena, related to the loss of radiation pattern and the directivity breakdown. We first simulate broad-band ground motions for a point-source characterized by a classic ω2 spectrum model. Fault finiteness is then introduced by means

Infrared radiation models for atmospheric ozone

Science.gov (United States)

Kratz, David P.; Ces, Robert D.

1988-01-01

A hierarchy of line-by-line, narrow-band, and broadband infrared radiation models are discussed for ozone, a radiatively important atmospheric trace gas. It is shown that the narrow-band (Malkmus) model is in near-precise agreement with the line-by-line model, thus providing a means of testing narrow-band Curtis-Godson scaling, and it is found that this scaling procedure leads to errors in atmospheric fluxes of up to 10 percent. Moreover, this is a direct consequence of the altitude dependence of the ozone mixing ratio. Somewhat greater flux errors arise with use of the broadband model, due to both a lesser accuracy of the broadband scaling procedure and to inherent errors within the broadband model, despite the fact that this model has been tuned to the line-by-line model.

ARTIST: advanced radiation-tolerant information and sensor system for teleoperation

International Nuclear Information System (INIS)

Schmidt, D.; Pathe, V.; Ostertag, M.; Dittrich, F.; Dumbreck, A.; Sirat, G.; Katzouraki, M.

1993-01-01

ARTIST integrates a stereoscopic camera and a rangefinder as sensor package into a high-precision pan-and-tilt head and represents the recorded data in a clear and comprehensive way for telemanipulation and control tasks as well as for remote driving. The sensors as well as the pan-and-tilt head are radiation-tolerant so they can be used in nuclear environments. The pan-and-tilt head and work station are completely configured and developed with the emphasis on multisensor integration, real-time video processing and graphical position representation. An efficient man-machine-interface appropriate software is included. (author)

Evaluation of testing strategies for the radiation tolerant ATLAS n **+-in-n pixel sensor

CERN Document Server

Klaiber Lodewigs, Jonas M

2003-01-01

The development of particle tracker systems for high fluence environments in new high-energy physics experiments raises new challenges for the development, manufacturing and reliable testing of radiation tolerant components. The ATLAS pixel detector for use at the LHC, CERN, is designed to cover an active sensor area of 1.8 m**2 with 1.1 multiplied by 10 **8 read-out channels usable for a particle fluence up to 10 **1**5 cm**-**2 (1 MeV neutron equivalent) and an ionization dose up to 500 kGy of mainly charged hadron radiation. To cope with such a harsh environment the ATLAS Pixel Collaboration has developed a radiation hard n **+-in-n silicon pixel cell design with a standard cell size of 50 multiplied by 400 mum**2. Using this design on an oxygenated silicon substrate, sensor production has started in 2001. This contribution describes results gained during the development of testing procedures of the ATLAS pixel sensor and evaluates quality assurance procedures regarding their relevance for detector operati...

Estimating carbon dioxide fluxes from temperate mountain grasslands using broad-band vegetation indices

Directory of Open Access Journals (Sweden)

G. Wohlfahrt

2010-02-01

Full Text Available The broad-band normalised difference vegetation index (NDVI and the simple ratio (SR were calculated from measurements of reflectance of photosynthetically active and short-wave radiation at two temperate mountain grasslands in Austria and related to the net ecosystem CO₂ exchange (NEE measured concurrently by means of the eddy covariance method. There was no significant statistical difference between the relationships of midday mean NEE with narrow- and broad-band NDVI and SR, measured during and calculated for that same time window, respectively. The skill of broad-band NDVI and SR in predicting CO₂ fluxes was higher for metrics dominated by gross photosynthesis and lowest for ecosystem respiration, with NEE in between. A method based on a simple light response model whose parameters were parameterised based on broad-band NDVI allowed to improve predictions of daily NEE and is suggested to hold promise for filling gaps in the NEE time series. Relationships of CO₂ flux metrics with broad-band NDVI and SR however generally differed between the two studied grassland sites indicting an influence of additional factors not yet accounted for.

Object-Oriented Hierarchy Radiation Consistency for Different Temporal and Different Sensor Images

Directory of Open Access Journals (Sweden)

Nan Su

2018-02-01

Full Text Available In the paper, we propose a novel object-oriented hierarchy radiation consistency method for dense matching of different temporal and different sensor data in the 3D reconstruction. For different temporal images, our illumination consistency method is proposed to solve both the illumination uniformity for a single image and the relative illumination normalization for image pairs. Especially in the relative illumination normalization step, singular value equalization and linear relationship of the invariant pixels is combined used for the initial global illumination normalization and the object-oriented refined illumination normalization in detail, respectively. For different sensor images, we propose the union group sparse method, which is based on improving the original group sparse model. The different sensor images are set to a similar smoothness level by the same threshold of singular value from the union group matrix. Our method comprehensively considered the influence factors on the dense matching of the different temporal and different sensor stereoscopic image pairs to simultaneously improve the illumination consistency and the smoothness consistency. The radiation consistency experimental results verify the effectiveness and superiority of the proposed method by comparing two other methods. Moreover, in the dense matching experiment of the mixed stereoscopic image pairs, our method has more advantages for objects in the urban area.

Modelling the propagation of terahertz radiation through a tissue simulating phantom

International Nuclear Information System (INIS)

Walker, Gillian C; Berry, Elizabeth; Smye, Stephen W; Zinov'ev, Nick N; Fitzgerald, Anthony J; Miles, Robert E; Chamberlain, Martyn; Smith, Michael A

2004-01-01

Terahertz (THz) frequency radiation, 0.1 THz to 20 THz, is being investigated for biomedical imaging applications following the introduction of pulsed THz sources that produce picosecond pulses and function at room temperature. Owing to the broadband nature of the radiation, spectral and temporal information is available from radiation that has interacted with a sample; this information is exploited in the development of biomedical imaging tools and sensors. In this work, models to aid interpretation of broadband THz spectra were developed and evaluated. THz radiation lies on the boundary between regions best considered using a deterministic electromagnetic approach and those better analysed using a stochastic approach incorporating quantum mechanical effects, so two computational models to simulate the propagation of THz radiation in an absorbing medium were compared. The first was a thin film analysis and the second a stochastic Monte Carlo model. The Cole-Cole model was used to predict the variation with frequency of the physical properties of the sample and scattering was neglected. The two models were compared with measurements from a highly absorbing water-based phantom. The Monte Carlo model gave a prediction closer to experiment over 0.1 to 3 THz. Knowledge of the frequency-dependent physical properties, including the scattering characteristics, of the absorbing media is necessary. The thin film model is computationally simple to implement but is restricted by the geometry of the sample it can describe. The Monte Carlo framework, despite being initially more complex, provides greater flexibility to investigate more complicated sample geometries

Evaluation of local radiation damage in silicon sensor via charge collection mapping with the Timepix read-out chip

International Nuclear Information System (INIS)

Platkevic, M; Jakubek, J; Jakubek, M; Pospisil, S; Zemlicka, J; Havranek, V; Semian, V

2013-01-01

Studies of radiation hardness of silicon sensors are standardly performed with single-pad detectors evaluating their global electrical properties. In this work we introduce a technique to visualize and determine the spatial distribution of radiation damage across the area of a semiconductor sensor. The sensor properties such as charge collection efficiency and charge diffusion were evaluated locally at many points of the sensor creating 2D maps. For this purpose we used a silicon sensor bump bonded to the pixelated Timepix read-out chip. This device, operated in Time-over-threshold (TOT) mode, allows for the direct energy measurement in each pixel. Selected regions of the sensor were intentionally damaged by defined doses (up to 10 12 particles/cm 2 ) of energetic protons (of 2.5 and 4 MeV). The extent of the damage was measured in terms of the detector response to the same ions. This procedure was performed either on-line during irradiation or off-line after it. The response of the detector to each single particle was analyzed determining the charge collection efficiency and lateral charge diffusion. We evaluated the changes of these parameters as a function of radiation dose. These features are related to the local properties such as the spatial homogeneity of the sensor. The effect of radiation damage was also independently investigated measuring local changes of signal response to γ, and X rays and alpha particles.

Chalcogenide Glass Radiation Sensor; Materials Development, Design and Device Testing

Energy Technology Data Exchange (ETDEWEB)

Mitkova, Maria; Butt, Darryl; Kozicki, Michael; Barnaby, Hugo

2013-04-30

studied the effect of x-rays and γ-rays, on thin film chalcogenide glasses and applied them in conjunction with film incorporating a silver source in a new type of radiation sensor for which we have an US patent application [3]. In this report, we give data about our studies regarding our designed radiation sensor along with the testing and performance at various radiation doses. These studies have been preceded by materials characterization research related to the compositional and structural characteristics of the active materials used in the radiation sensor design. During the work on the project, we collected a large volume of material since every experiment was repeated many times to verify the results. We conducted a comprehensive material research, analysis and discussion with the aim to understand the nature of the occurring effects, design different structures to harness these effects, generated models to aid in the understanding the effects, built different device structures and collected data to quantify device performance. These various aspects of our investigation have been detailed in previous quarterly reports. In this report, we present our main results and emphasize on the results pertaining to the core project goals materials development, sensor design and testing and with an emphasis on classifying the appropriate material and design for the optimal application. The report has three main parts: (i) Presentation of the main data; (ii) Bulleted summary of the most important results; (iii) List of the patent, journal publications, conference proceedings and conferences participation, occurring as a result of working on the project.

The development of gamma energy identify algorithm for compact radiation sensors using stepwise refinement technique

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hyun Jun [Div. of Radiation Regulation, Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Ye Won; Kim, Hyun Duk; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Yi, Yun [Dept. of of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)

2017-06-15

A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under 104 (/0.09 cm{sup 2} of the scintillator surface). Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

Radiation hardness of CMOS monolithic active pixel sensors manufactured in a 0.18 μm CMOS process

Energy Technology Data Exchange (ETDEWEB)

Linnik, Benjamin [Goethe-Universitaet Frankfurt (Germany); Collaboration: CBM-MVD-Collaboration

2015-07-01

CMOS Monolithic Active Pixels Sensors (MAPS) are considered as the technology of choice for various vertex detectors in particle and heavy-ion physics including the STAR HFT, the upgrade of the ALICE ITS, the future ILC detectors and the CBM experiment at FAIR. To match the requirements of those detectors, their hardness to radiation is being improved, among others in a joined research activity of the Goethe University Frankfurt and the IPHC Strasbourg. It was assumed that combining an improved high resistivity (1-8 kΩcm) sensitive medium with the features of a 0.18 μm CMOS process, is suited to reach substantial improvements in terms of radiation hardness as compared to earlier sensor designs. This strategy was tested with a novel generation of sensor prototypes named MIMOSA-32 and MIMOSA-34. We show results on the radiation hardness of those sensors and discuss its impact on the design of future vertex detectors.

Development of semiconductor radiation sensors for portable alarm-dosimeter

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. K.; Moon, B. S.; Chung, C. E.; Hong, S. B.; Kim, J. Y.; Kim, J. B.; Han, S. H.; Lee, W. G. [Korea Atomic Energy Research Institute, Taejeon (Korea)

2001-01-01

We studied Semiconductor Radiation Sensors for Portable Alarm-Dosimeter. We calculated response functions for gamma energy 0.021, 0.122, 0.662, 0.835, 1.2 MeV using EGS4 codes. When we measured at various distance from source to detector, the detection efficiency of Si semiconductor detector was better than that of GM tube. The linear absorption coefficients of steel and aluminum plate were measured. These experimental results of the response of detector for intensity of radiation field coincide to the theoretical expectation. The count value of Si detector was changed with changing thickness of steel as changing threshold voltage of discriminator, and the linear absorption coefficient increased with increasing threshold voltage. Radiation detection efficiency shows difference at each threshold voltage condition. This results coincided to the theoretical simulation. 33 refs., 27 figs., 8 tabs. (Author)

Radiation sensors based on GaN microwires

Science.gov (United States)

Verheij, D.; Peres, M.; Cardoso, S.; Alves, L. C.; Alves, E.; Durand, C.; Eymery, J.; Lorenz, K.

2018-05-01

GaN microwires were shown to possess promising characteristics as building blocks for radiation resistant particle detectors. They were grown by metal organic vapour phase epitaxy with diameters between 1 and 2 μm and lengths around 20 μm. Devices were fabricated by depositing gold contacts at the extremities of the wires using photolithography. The response of these single wire radiation sensors was then studied under irradiation with 2 MeV protons. Severe degradation of the majority of devices only sets in for fluences above protons cm‑2 revealing good radiation resistance. During proton irradiation, a clear albeit small current gain was observed with a corresponding decay time below 1 s. Photoconductivity measurements upon irradiation with UV light were carried out before and after the proton irradiation. Despite a relatively low gain, attributed to significant dark currents caused by a high dopant concentration, fast response times of a few seconds were achieved comparable to state-of-the-art GaN nanowire photodetectors. Irradiation and subsequent annealing resulted in an overall improvement of the devices regarding their response to UV radiation. The photocurrent gain increased compared to the values that were obtained prior to the irradiation, without compromising the decay times. The results indicate the possibility of using GaN microwires not only as UV detectors, but also as particle detectors.

Performance of light sources and radiation sensors under low gravity realized by parabolic airplane flights

Science.gov (United States)

Hirai, Hiroaki; Kitaya, Yoshiaki; Hirai, Takehiro

A fundamental study was conducted to establish an experimental system for space farming. Since to ensure optimal light for plant cultivation in space is of grave importance, this study examined the performance of light sources and radiation sensors under microgravity conditions created during the parabolic airplane flight. Three kinds of light sources, a halogen bulb, a fluorescent tube, and blue and red LEDs, and ten models of radiation sensors available in the market were used for the experiment. Surface temperature of the light sources, output signals from the radiation sensors, spectroscopic characteristics were measured at the gravity levels of 0.01, 1.0 and 1.8 G for 20 seconds each during parabolic airplane flights. As a result, the performance of the halogen lamp was affected the most by the gravity level among the three light sources. Under the microgravity conditions which do not raise heat convection, the temperature of the halogen lamp rose and the output of the radiation sensors increased. Spectral distributions of the halogen lamp indicated that peak wavelength appeared the highest at the level of 0.01G, which contributed to the increase in light intensity. In the case of red and blue LEDs, which are promising light sources in space farming, the temperature of both LED chips rose but irradiance from red LED increased and that from blue LED decreased under microgravity conditions due to the different thermal characteristics.

Multi-sensor radiation detector system

International Nuclear Information System (INIS)

Foster, R.G.; Cyboron, R.D.

1975-01-01

The invention is a multi-sensor radiation detection system including a self-powered detector and an ion or fission chamber, preferably joined as a unitary structure, for removable insertion into a nuclear reactor. The detector and chamber are connected electrically in parallel, requiring but two conductors extending out of the reactor to external electrical circuitry which includes a load impedance, a voltage source, and switch means. The switch means are employed to alternately connect the detector and chamber either with th load impedance or with the load impedance and the voltage source. In the former orientation, current through the load impedance indicates flux intensity at the self-powered detector and in the latter orientation, the current indicates flux intensity at the detector and fission chamber, though almost all of the current is contributed by the fission chamber. (auth)

SREQP: A Solar Radiation Extraction and Query Platform for the Production and Consumption of Linked Data from Weather Stations Sensors

Directory of Open Access Journals (Sweden)

José Luis Sánchez-Cervantes

2016-01-01

Full Text Available Nowadays, solar radiation information is provided from sensors installed in different geographic locations and platforms of meteorological agencies. However, common formats such as PDF files and HTML documents to provide solar radiation information do not offer semantics in their content, and they may pose problems to integrate and fuse data from multiple resources. One of the challenges of sensors Web is the unification of data from multiple sources, although this type of information facilitates interoperability with other sensor Web systems. This research proposes architecture SREQP (Solar Radiation Extraction and Query Platform to extract solar radiation data from multiple external sources and merge them on a single and unique platform. SREQP makes use of Linked Data to generate a set of triples containing information about extracted data, which allows final users to query data through a SPARQL endpoint. The conceptual model was developed by using known vocabularies, such as SSN or WGS84. Moreover, an Analytic Hierarchy Process was carried out for the evaluation of SREQP in order to identify and evaluate the main features of Linked-Sensor-Data and the sensor Web systems. Results from the evaluation indicated that SREQP contained most of the features considered essential in Linked-Sensor-Data and sensor Web systems.

Hydrogenated Amorphous Silicon Sensor Deposited on Integrated Circuit for Radiation Detection

CERN Document Server

Despeisse, M; Jarron, P; Kaplon, J; Moraes, D; Nardulli, A; Powolny, F; Wyrsch, N

2008-01-01

Radiation detectors based on the deposition of a 10 to 30 mum thick hydrogenated amorphous silicon (a-Si:H) sensor directly on top of integrated circuits have been developed. The performance of this detector technology has been assessed for the first time in the context of particle detectors. Three different circuits were designed in a quarter micron CMOS technology for these studies. The so-called TFA (Thin-Film on ASIC) detectors obtained after deposition of a-Si:H sensors on the developed circuits are presented. High internal electric fields (104 to 105 V/cm) can be built in the a-Si:H sensor and overcome the low mobility of electrons and holes in this amorphous material. However, the deposited sensor's leakage current at such fields turns out to be an important parameter which limits the performance of a TFA detector. Its detailed study is presented as well as the detector's pixel segmentation. Signal induction by generated free carrier motion in the a-Si:H sensor has been characterized using a 660 nm pul...

Broadband Faraday isolator.

Science.gov (United States)

Berent, Michał; Rangelov, Andon A; Vitanov, Nikolay V

2013-01-01

Driving on an analogy with the technique of composite pulses in quantum physics, we theoretically propose a broadband Faraday rotator and thus a broadband optical isolator, which is composed of sequences of ordinary Faraday rotators and achromatic quarter-wave plates rotated at the predetermined angles.

Single-Crystal Sapphire Optical Fiber Sensor Instrumentation

Energy Technology Data Exchange (ETDEWEB)

Pickrell, Gary [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States); Scott, Brian [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States); Wang, Anbo [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States); Yu, Zhihao [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States)

2013-12-31

This report summarizes technical progress on the program “Single-Crystal Sapphire Optical Fiber Sensor Instrumentation,” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. This project was completed in three phases, each with a separate focus. Phase I of the program, from October 1999 to April 2002, was devoted to development of sensing schema for use in high temperature, harsh environments. Different sensing designs were proposed and tested in the laboratory. Phase II of the program, from April 2002 to April 2009, focused on bringing the sensor technologies, which had already been successfully demonstrated in the laboratory, to a level where the sensors could be deployed in harsh industrial environments and eventually become commercially viable through a series of field tests. Also, a new sensing scheme was developed and tested with numerous advantages over all previous ones in Phase II. Phase III of the program, September 2009 to December 2013, focused on development of the new sensing scheme for field testing in conjunction with materials engineering of the improved sensor packaging lifetimes. In Phase I, three different sensing principles were studied: sapphire air-gap extrinsic Fabry-Perot sensors; intensity-based polarimetric sensors; and broadband polarimetric sensors. Black body radiation tests and corrosion tests were also performed in this phase. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. At the beginning of Phase II, in June 2004, the BPDI sensor was tested at the Wabash River coal gasifier

Evaluation of broadband surface solar irradiance derived from the Ozone Monitoring Instrument

NARCIS (Netherlands)

Wang, P.; Sneep, M.; Veefkind, J.P.; Stammes, P.; Levelt, P.F.

2014-01-01

Surface solar irradiance (SSI) data are important for planning and estimating the production of solar power plants. Long-term high quality surface solar radiation data are needed for monitoring climate change. This paper presents a new surface solar irradiance dataset, the broadband (0.2–4 ?m)

Research on continuous environmental radiation monitoring system for NPP based on wireless sensor network

International Nuclear Information System (INIS)

Fu Hailong; Jia Mingchun; Peng Guichu

2010-01-01

According to the characteristics of environmental gamma radiation monitoring and the requirement of nuclear power plant (NPP) developing, a new continuous environmental radiation monitoring system based on wireless sensor network (WSN) was presented. The basic concepts and application of WSN were introduced firstly. And then the characteristics of the new system were analyzed. At the same time the configuration of the WSN and the whole structure of the system were built. Finally, the crucial techniques used in system designing, such as the design of sensor node, the choice of communication mode and protocol, the time synchronization and space location, the security of the network and the faults tolerance were introduced. (authors)

Broadband radiometric LED measurements

Science.gov (United States)

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-09-01

At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

An edge-TCT setup for the investigation of radiation damaged silicon sensors

Energy Technology Data Exchange (ETDEWEB)

Feindt, Finn; Scharf, Christian; Garutti, Erika; Klanner, Robert [Institute for Experimental Physics, Hamburg University, Luruper Chaussee 149, D-22761 Hamburg (Germany)

2016-07-01

The aim of this work is to measure the electric field, drift velocity and charge collection of electrons and holes in radiation-damaged silicon strip sensors. For this purpose the edge Transient Current Technique (TCT) is employed. In contrast to conventional TCT, this method requires light from a sub-ns pulsed, infrared laser to be focused to a μm-size spot and scanned across the polished edge of a strip sensor. Thus electron-hole pairs are generated at a known depth in the sensor. Electrons and holes drift in the electric field and induce transient currents on the sensor electrodes. The current wave forms are analyzed as a function of the applied voltage and the position of the laser focus in order to determine the electric field, the drift velocities and the charge collection. In this talk the setup and the procedure for polishing the sensor edge are described, and first results, regarding the measurement of the laser light focus are presented.

Physical retrieval of precipitation water contents from Special Sensor Microwave/Imager (SSM/I) data. Part 1: A cloud ensemble/radiative parameterization for sensor response (report version)

Science.gov (United States)

Olson, William S.; Raymond, William H.

1990-01-01

The physical retrieval of geophysical parameters based upon remotely sensed data requires a sensor response model which relates the upwelling radiances that the sensor observes to the parameters to be retrieved. In the retrieval of precipitation water contents from satellite passive microwave observations, the sensor response model has two basic components. First, a description of the radiative transfer of microwaves through a precipitating atmosphere must be considered, because it is necessary to establish the physical relationship between precipitation water content and upwelling microwave brightness temperature. Also the spatial response of the satellite microwave sensor (or antenna pattern) must be included in the description of sensor response, since precipitation and the associated brightness temperature field can vary over a typical microwave sensor resolution footprint. A 'population' of convective cells, as well as stratiform clouds, are simulated using a computationally-efficient multi-cylinder cloud model. Ensembles of clouds selected at random from the population, distributed over a 25 km x 25 km model domain, serve as the basis for radiative transfer calculations of upwelling brightness temperatures at the SSM/I frequencies. Sensor spatial response is treated explicitly by convolving the upwelling brightness temperature by the domain-integrated SSM/I antenna patterns. The sensor response model is utilized in precipitation water content retrievals.

Broadband Internet and Income Inequality

OpenAIRE

HOUNGBONON , Georges Vivien; Liang , Julienne

2017-01-01

Policy makers are aiming for a large coverage of high-speed broadband Internet. However , there is still a lack of evidence about its effects on income distribution. In this paper, we investigate the effects of fixed broadband Internet on mean income and income inequality using a unique town-level data on broadband adoption and quality in France. We find that broadband adoption and quality raise mean income and lower income inequality. These results are robust to initial conditions, and yield...

Modeling of Broadband Liners Applied to the Advanced Noise Control Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.

2015-01-01

The broadband component of fan noise has grown in relevance with an increase in bypass ratio and incorporation of advanced fan designs. Therefore, while the attenuation of fan tones remains a major factor in engine nacelle acoustic liner design, the simultaneous reduction of broadband fan noise levels has received increased interest. As such, a previous investigation focused on improvements to an established broadband acoustic liner optimization process using the Advanced Noise Control Fan (ANCF) rig as a demonstrator. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom liner designs were carried through design, fabrication, and testing. This paper addresses a number of areas for further research identified in the initial assessment of the ANCF study. Specifically, incident source specification and uncertainty in some aspects of the predicted liner impedances are addressed. This information is incorporated in updated predictions of the liner performance and comparisons with measurement are greatly improved. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of various liner designs. This study also provides further confidence in the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

Broadband Radiometric LED Measurements

OpenAIRE

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-01-01

At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(��) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irr...

Extreme temperature robust optical sensor designs and fault-tolerant signal processing

Science.gov (United States)

Riza, Nabeel Agha [Oviedo, FL; Perez, Frank [Tujunga, CA

2012-01-17

Silicon Carbide (SiC) probe designs for extreme temperature and pressure sensing uses a single crystal SiC optical chip encased in a sintered SiC material probe. The SiC chip may be protected for high temperature only use or exposed for both temperature and pressure sensing. Hybrid signal processing techniques allow fault-tolerant extreme temperature sensing. Wavelength peak-to-peak (or null-to-null) collective spectrum spread measurement to detect wavelength peak/null shift measurement forms a coarse-fine temperature measurement using broadband spectrum monitoring. The SiC probe frontend acts as a stable emissivity Black-body radiator and monitoring the shift in radiation spectrum enables a pyrometer. This application combines all-SiC pyrometry with thick SiC etalon laser interferometry within a free-spectral range to form a coarse-fine temperature measurement sensor. RF notch filtering techniques improve the sensitivity of the temperature measurement where fine spectral shift or spectrum measurements are needed to deduce temperature.

Development of n+-in-p large-area silicon microstrip sensors for very high radiation environments – ATLAS12 design and initial results

International Nuclear Information System (INIS)

Unno, Y.; Edwards, S.O.; Pyatt, S.; Thomas, J.P.; Wilson, J.A.; Kierstead, J.; Lynn, D.; Carter, J.R.; Hommels, L.B.A.; Robinson, D.; Bloch, I.; Gregor, I.M.; Tackmann, K.; Betancourt, C.; Jakobs, K.; Kuehn, S.; Mori, R.; Parzefall, U.; Wiik-Fucks, L.; Clark, A.

2014-01-01

We have been developing a novel radiation-tolerant n + -in-p silicon microstrip sensor for very high radiation environments, aiming for application in the high luminosity large hadron collider. The sensors are fabricated in 6 in., p-type, float-zone wafers, where large-area strip sensor designs are laid out together with a number of miniature sensors. Radiation tolerance has been studied with ATLAS07 sensors and with independent structures. The ATLAS07 design was developed into new ATLAS12 designs. The ATLAS12A large-area sensor is made towards an axial strip sensor and the ATLAS12M towards a stereo strip sensor. New features to the ATLAS12 sensors are two dicing lines: standard edge space of 910 μm and slim edge space of 450 μm, a gated punch-through protection structure, and connection of orphan strips in a triangular corner of stereo strips. We report the design of the ATLAS12 layouts and initial measurements of the leakage current after dicing and the resistivity of the wafers

Real time sensor for therapeutic radiation delivery

International Nuclear Information System (INIS)

Bliss, M.; Craig, R.A.; Reeder, P.L.

1998-01-01

The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body. 14 figs

Micro-discharge noise and radiation damage of silicon microstrip sensors

International Nuclear Information System (INIS)

Ohsugi, T.; Iwata, Y.; Ohyama, H.; Ohmoto, T.; Yoshikawa, M.; Handa, T.; Kurino, K.; Fujita, K.; Kitabayashi, H.; Tamura, N.; Hatakenaka, T.; Maeohmichi, M.; Takahata, M.; Nakao, M.; Iwasaki, H.; Kohriki, T.; Terada, S.; Unno, Y.; Takashima, R.; Yamamoto, K.; Yamamura, K.

1996-01-01

We have examined experimentally some existing ideas for improving the radiation hardness of silicon microstrip sensors. We confirm that the extended electrode and the deep implant-strip proposed on the basis of simulation studies works effectively to suppress micro-discharge as well as junction breakdown of the bias or guard ring. For an integrated coupling capacitor a double layer structure of SiO 2 and Si 3 N 4 provides better radiation hardness than that of single SiO 2 coupling in our design conditions. The onset voltage of the micro-discharge on the bias/guard ring has been studied for an extended electrode and a floating guard ring. (orig.)

Beam test of novel n-in-p strip sensors for high radiation environment

Science.gov (United States)

Kubota, T.; Kishida, T.; Jinnouchi, O.; Ikegami, Y.; Unno, Y.; Terada, S.; Mitsui, S.; Tamii, A.; Aoi, T.; Hanagaki, K.; Hara, K.; Kimura, N.; Takashima, R.; Takubo, Y.; Tojo, J.; Nagai, K.; Nakano, I.; Yorita, K.

2013-12-01

Highly radiation tolerant n-in-p strip sensors have been developed for the high-luminosity LHC (HL-LHC). This paper reports the results of measurements with 392 MeV kinetic energy proton beam at RCNP in December 2011. The data was taken with a new DAQ system consisting of an universal read-out board ‘SEABAS’ and beam tracking telescopes whose spacial resolution is better than 5 μm. The aim of this beam test is to evaluate the new 1 cm×1 cm n-in-p miniature sensors before and after 1015 neq cm-2 irradiation. The median charge of un-irradiated sensor is 6.2 fC at full depletion voltage, while the median charge after 1015 neq cm-2 irradiation of the sensor is 4.2 fC. The novel Punch-Through-Protection (PTP) has been implemented in these sensors. The length of active region of the sensor around PTP is observed to be decreased by 12 μm in the irradiated sensors at 1015 neq cm-2.

Driving demand for broadband networks and services

CERN Document Server

Katz, Raul L

2014-01-01

This book examines the reasons why various groups around the world choose not to adopt broadband services and evaluates strategies to stimulate the demand that will lead to increased broadband use. It introduces readers to the benefits of higher adoption rates while examining the progress that developed and emerging countries have made in stimulating broadband demand. By relying on concepts such as a supply and demand gap, broadband price elasticity, and demand promotion, this book explains differences between the fixed and mobile broadband demand gap, introducing the notions of substitution and complementarity between both platforms. Building on these concepts, ‘Driving Demand for Broadband Networks and Services’ offers a set of best practices and recommendations aimed at promoting broadband demand.  The broadband demand gap is defined as individuals and households that could buy a broadband subscription because they live in areas served by telecommunications carriers but do not do so because of either ...

In-Space Distributed Fiber Optic Hydrogen Leak Sensor, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Broadband Photonics Inc. proposes development of a patent-pending distributed fiber optic sensor for in-space hydrogen leak detection. Reliable and fast detection of...

Radiation-hard Active Pixel Sensors for HL-LHC Detector Upgrades based on HV-CMOS Technology

International Nuclear Information System (INIS)

Miucci, A; Gonzalez-Sevilla, S; Ferrere, D; Iacobucci, G; Rosa, A La; Muenstermann, D; Gonella, L; Hemperek, T; Hügging, F; Krüger, H; Obermann, T; Wermes, N; Garcia-Sciveres, M; Backhaus, M; Capeans, M; Feigl, S; Nessi, M; Pernegger, H; Ristic, B; George, M

2014-01-01

Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown

Low-Noise, UV-to-SWIR Broadband Photodiodes for Large-Format Focal Plane Array Sensors, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Broadband focal plane arrays, operating in UV-to-SWIR wavelength range, are required for atmospheric monitoring of greenhouse gases. Currently, separate image...

Broadband infrared photoluminescence in silicon nanowires with high density stacking faults.

Science.gov (United States)

Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Liu, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

2015-02-07

Making silicon an efficient light-emitting material is an important goal of silicon photonics. Here we report the observation of broadband sub-bandgap photoluminescence in silicon nanowires with a high density of stacking faults. The photoluminescence becomes stronger and exhibits a blue shift under higher laser powers. The super-linear dependence on excitation intensity indicates a strong competition between radiative and defect-related non-radiative channels, and the spectral blue shift is ascribed to the band filling effect in the heterostructures of wurtzite silicon and cubic silicon created by stacking faults.

Radiation damage studies on STAR250 CMOS sensor at 300 keV for electron microscopy

International Nuclear Information System (INIS)

Faruqi, A.R.; Henderson, R.; Holmes, J.

2006-01-01

There is a pressing need for better electronic detectors to replace film for recording high-resolution images using electron cryomicroscopy. Our previous work has shown that direct electron detection in CMOS sensors is promising in terms of resolution and efficiency at 120 keV [A.R. Faruqi, R. Henderson, M. Prydderch, R. Turchetta, P. Allport, A. Evans, Nucl. Instr. and Meth. 546 (2005) 170], but in addition, the detectors must not be damaged by the electron irradiation. We now present new measurements on the radiation tolerance of a 25 μm pitch CMOS active-pixel sensor, the STAR250, which was designed by FillFactory using radiation-hard technology for space applications. Our tests on the STAR250 aimed to establish the imaging performance at 300 keV following irradiation. The residual contrast, measured on shadow images of a 300 mesh grid, was >80% after corrections for increased dark current, following irradiation with up to 5x10 7 electrons/pixel (equivalent to 80,000 electron/μm 2 ). A CMOS sensor with this degree of radiation tolerance would survive a year of normal usage for low-dose electron cryomicroscopy, which is a very useful advance

The Microflown, an acoustic particle velocity sensor

NARCIS (Netherlands)

de Bree, H.E.

2003-01-01

The Microflown is an acoustic sensor directly measuring particle velocity instead of sound pressure, which is usually measured by conventional microphones. Since its invention in 1994 it is mostly used for measurement purposes (broadband1D and 3D-sound intensity measurement and acoustic impedance).

Radiation area monitor device and method

Science.gov (United States)

Vencelj, Matjaz; Stowe, Ashley C.; Petrovic, Toni; Morrell, Jonathan S.; Kosicek, Andrej

2018-01-30

A radiation area monitor device/method, utilizing: a radiation sensor; a rotating radiation shield disposed about the radiation sensor, wherein the rotating radiation shield defines one or more ports that are transparent to radiation; and a processor operable for analyzing and storing a radiation fingerprint acquired by the radiation sensor as the rotating radiation shield is rotated about the radiation sensor. Optionally, the radiation sensor includes a gamma and/or neutron radiation sensor. The device/method selectively operates in: a first supervised mode during which a baseline radiation fingerprint is acquired by the radiation sensor as the rotating radiation shield is rotated about the radiation sensor; and a second unsupervised mode during which a subsequent radiation fingerprint is acquired by the radiation sensor as the rotating radiation shield is rotated about the radiation sensor, wherein the subsequent radiation fingerprint is compared to the baseline radiation fingerprint and, if a predetermined difference threshold is exceeded, an alert is issued.

Quantifying the Benefits of Shallow Posthole Installation for the Future French Permanent Broadband Stations

Science.gov (United States)

Vergne, J.; Charade, O.; Bonaime, S.; Louis-Xavier, T.; Arnold, B.

2015-12-01

In the framework of the RESIF (réseau sismologique et géodésique français) infrastructure, more than one hundred new permanent broadband stations have to be deployed in metropolitan France within the forthcoming years. This requires a standardized installation method able to provide good noise level performance at a reasonable cost, especially for the 60 percent of stations that we expect to be settled in open environments. During the last two years we tested various types of sensor's hosting infrastructures with a strong focus on recently released posthole sensors that can be deployed at the bottom of shallow boreholes. Tests were performed at 3 different sites (two GEOSCOPE stations and a dedicated open-field prototype site) with geological conditions spanning from hard rocks to very soft soils. On each site, posthole sensors were deployed at different depths, from the surface to a maximum of 20m deep, and in different types of casing. Moreover, a reference sensor, either installed in a tunnel, a cellar or a seismic vault, has been operated continuously. We present a comprehensive comparison of the seismic noise level measured in the different hosting infrastructures and for several frequency bands corresponding to various sources of noise. At high and low frequencies, seismic noise level in some boreholes equals or outperforms the one obtained for the reference sensors. Between 0.005 and 0.05Hz, we observe a strong decrease of seismic noise level on the horizontal components in the deepest boreholes compared to near surface installations. This improvement can reach up to 30dB and is mostly due to a reduction in tilt noise induced by wind or local pressure variations. However, the absolute noise level that can be achieved clearly depends on the local geology. All these tests, together with estimated installation costs, point toward the deployment of sensors in shallow boreholes at the future French broadband stations located in open environments.

A 0.18μm CMOS low-power radiation sensor for UWB wireless transmission

International Nuclear Information System (INIS)

Crepaldi, M; Demarchi, D; Gabrielli, A; Khan, A; Pikhay, E; Roizin, Y; Villani, G; Zhang, Z

2012-01-01

The paper describes the design of a floating gate MOS sensor embedded in a readout CMOS element, used as a radiation monitor. A maximum sensitivity of 1 mV/rad is estimated within an absorbed dose range from 1 to 10 krad. The paper shows in particular the design of a microelectronic circuit that includes the floating gate sensor, an oscillator, a modulator, a transmitter and an integrated antenna. A prototype of the circuit has recently been simulated, fabricated and tested exploiting a commercial 180 nm, 4 metal CMOS technology. Some simulation results are presented along with a measurement of the readout circuit response to an input voltage swing. Given the small estimated area of the complete chip prototype, that is less than 1 mm 2 , the chip fits a large variety of applications, from spot radiation monitoring systems in medicine to punctual measurements or radiation level in High-Energy Physics experiments.

Hybrid emergency radiation detection: a wireless sensor network application for consequence management of a radiological release

Science.gov (United States)

Kyker, Ronald D.; Berry, Nina; Stark, Doug; Nachtigal, Noel; Kershaw, Chris

2004-08-01

The Hybrid Emergency Radiation Detection (HERD) system is a rapidly deployable ad-hoc wireless sensor network for monitoring the radiation hazard associated with a radiation release. The system is designed for low power, small size, low cost, and rapid deployment in order to provide early notification and minimize exposure. The many design tradeoffs, decisions, and challenges in the implementation of this wireless sensor network design will be presented and compared to the commercial systems available. Our research in a scaleable modular architectural highlights the need and implementation of a system level approach that provides flexibility and adaptability for a variety of applications. This approach seeks to minimize power, provide mission specific specialization, and provide the capability to upgrade the system with the most recent technology advancements by encapsulation and modularity. The implementation of a low power, widely available Real Time Operating System (RTOS) for multitasking with an improvement in code maintenance, portability, and reuse will be presented. Finally future design enhancements technology trends affecting wireless sensor networks will be presented.

Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.; Ayle, Earl; Ichihashi, Fumitaka

2014-01-01

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more desirable. This paper describes improvements to a previously established broadband acoustic liner optimization process using the Advanced Noise Control Fan rig as a demonstrator. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom designs are carried through design, fabrication, and testing to validate the efficacy of the design process. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of these liner designs. This study also provides an application for demonstrating the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

Wireless powering for low-power distributed sensors

Directory of Open Access Journals (Sweden)

Popović Zoya B.

2006-01-01

Full Text Available In this paper, an overview of the field of wireless powering is presented with an emphasis on low-power applications. Several rectenna elements and arrays are discussed in more detail: (1 a 10-GHz array for powering sensors in aircraft wings; (2 a single antenna in the 2.4-GHz ISM band for low-power assisted-living sensors; and (3 a broadband array for power harvesting in the 2-18GHz frequency range.

UV Radiation Detection Using Optical Sensor Based on Eu3+ Doped PMMA

Directory of Open Access Journals (Sweden)

Miluski Piotr

2016-12-01

Full Text Available Progress in UV treatment applications requires new compact and sensor constructions. In the paper a hybrid (organic-inorganic rare-earth-based polymeric UV sensor construction is proposed. The efficient luminescence of poly(methyl methacrylate (PMMA matrix doped by europium was used for testing the optical sensor (optrode construction. The europium complex assures effective luminescence in the visible range with well determined multi-peak spectrum emission enabling construction of the optrode. The fabricated UV optical fibre sensor was used for determination of Nd:YAG laser intensity measurements at the third harmonic (355 nm in the radiation power range 5.0-34.0 mW. The multi-peak luminescence spectrum was used for optimization of the measurement formula. The composition of luminescent peak intensity enables to increase the slope of sensitivity up to −2.8 mW-1. The obtained results and advantages of the optical fibre construction enable to apply it in numerous UV detection systems.

Radiation dosimetry properties of smart-phone CMOS sensors

International Nuclear Information System (INIS)

Van Hoey, Olivier; Salavrakos, Alexia; Marques, Antonio; Nagao, Alexandre; Vanhavere, Filip; Cauwels, Vanessa; Nascimento, Luana F.; Willems, Ruben

2016-01-01

During the past years, several smart-phone applications have been developed for radiation detection. These applications measure radiation using the smart-phone camera complementary metal-oxide-semiconductor sensor. They are potentially useful for data collection and personal dose assessment in case of a radiological incident. However, it is important to assess these applications. Six applications were tested by means of irradiations with calibrated X-ray and gamma sources. It was shown that the measurement stabilises only after at least 10-25 min. All applications exhibited a flat dose rate response in the studied ambient dose equivalent range from 2 to 1000 μSv h -1 . Most applications significantly over- or underestimate the dose rate or are not calibrated in terms of dose rate. A considerable energy dependence was observed below 100 keV but not for the higher energy range more relevant for incident scenarios. Photon impact angle variation gave a measured signal variation of only about 10 %. (authors)

Device Simulation of Monolithic Active Pixel Sensors: Radiation Damage Effects

International Nuclear Information System (INIS)

Fourches, N.T.

2009-01-01

Vertexing for the future International Linear Collider represents a challenging goal because of the high spatial resolution required with low material budget and high ionizing radiation tolerance. CMOS Monolithic Active Pixel Sensors (MAPS) represent a good potential solution for this purpose. Up to now many MAPS sensors have been developed. They are based on various architectures and manufactured in different processes. However, up so far, the sensor diode has not been the subject of extensive modelization and simulation. Published simulation studies of sensor-signal formation have been less numerous than measurements on real sensors. This is a cause for concern because such sensor is physically based on the partially depleted diode, in the vicinity of which the electric field collects the minority carriers generated by an incident MIP (minimum ionizing particle). Although the microscopic mechanisms are well known and modelled, the global physical mechanisms for signal formation are not very rigorously established. This is partly due to the presence of a predominant diffusion component in the charge transport. We present here simulations mainly based on the S-PISCES code, in which physical mechanisms affecting transport are taken into account. Diffusion, influence of residual carrier concentration due to the doping level in the sensitive volume, and more importantly charge trapping due to deep levels in the active (detecting) layer are studied together with geometric aspects. The effect of neutron irradiation is studied to assess the effects of deep traps. A comparison with available experimental data, obtained on processed MAPS before or after neutron irradiation will be introduced. Simulated reconstruction of the Minimum Ionizing Particle (MIP) point of impact in two dimensions is also investigated. For further steps, guidelines for process choices of next Monolithic Active Pixel Sensors are introduced. (authors)

Thermal microphotonic sensor and sensor array

Science.gov (United States)

Watts, Michael R [Albuquerque, NM; Shaw, Michael J [Tijeras, NM; Nielson, Gregory N [Albuquerque, NM; Lentine, Anthony L [Albuquerque, NM

2010-02-23

A thermal microphotonic sensor is disclosed for detecting infrared radiation using heat generated by the infrared radiation to shift the resonant frequency of an optical resonator (e.g. a ring resonator) to which the heat is coupled. The shift in the resonant frequency can be determined from light in an optical waveguide which is evanescently coupled to the optical resonator. An infrared absorber can be provided on the optical waveguide either as a coating or as a plate to aid in absorption of the infrared radiation. In some cases, a vertical resonant cavity can be formed about the infrared absorber to further increase the absorption of the infrared radiation. The sensor can be formed as a single device, or as an array for imaging the infrared radiation.

Radiation-hard Active Pixel Sensors for HL-LHC Detector Upgrades based on HV-CMOS Technology

CERN Document Server

Miucci, A; Hemperek, T.; Hügging, F.; Krüger, H.; Obermann, T.; Wermes, N.; Garcia-Sciveres, M.; Backhaus, M.; Capeans, M.; Feigl, S.; Nessi, M.; Pernegger, H.; Ristic, B.; Gonzalez-Sevilla, S.; Ferrere, D.; Iacobucci, G.; Rosa, A.La; Muenstermann, D.; George, M.; Grosse-Knetter, J.; Quadt, A.; Rieger, J.; Weingarten, J.; Bates, R.; Blue, A.; Buttar, C.; Hynds, D.; Kreidl, C.; Peric, I.; Breugnon, P.; Pangaud, P.; Godiot-Basolo, S.; Fougeron, D.; Bompard, F.; Clemens, J.C.; Liu, J; Barbero, M.; Rozanov, A

2014-01-01

Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. 1Corresponding author. c CERN 2014, published under the terms of the Creative Commons Attribution 3.0 License by IOP Publishing Ltd and Sissa Medialab srl. Any further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation and DOI. doi:10.1088/1748-0221/9/05/C050642014 JINST 9 C05064 A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation a...

Refractive Index Sensor Based on a Metal–Insulator–Metal Waveguide Coupled with a Symmetric Structure

Directory of Open Access Journals (Sweden)

Shubin Yan

2017-12-01

Full Text Available In this study, a new refractive index sensor based on a metal–insulator–metal waveguide coupled with a notched ring resonator and stub is designed. The finite element method is used to study the propagation characteristics of the sensor. According to the calculation results, the transmission spectrum exhibits a typical Fano resonance shape. The phenomenon of Fano resonance is caused by the coupling between the broadband spectrum and narrowband spectrum. In the design, the broadband spectrum signal is generated by the stub, while the narrowband spectrum signal is generated by the notched ring resonator. In addition, the structural parameters of the resonators and the structure filled with media of different refractive indices are varied to study the sensing properties. The maximum achieved sensitivity of the sensor reached 1071.4 nm/RIU. The results reveal potential applications of the coupled system in the field of sensors.

Ultra-broadband mid-wave-IR upconversion detection

DEFF Research Database (Denmark)

Barh, Ajanta; Pedersen, Christian; Tidemand-Lichtenberg, Peter

2017-01-01

In this Letter, we demonstrate efficient room temperature detection of ultra-broadband mid-wave-infrared (MWIR) light with an almost flat response over more than 1200 nm, exploiting an efficient nonlinear upconversion technique. Black-body radiation from a hot soldering iron rod is used as the IR...... test source. Placing a 20 mm long periodically poled lithium niobate crystal in a compact intra-cavity setup (> 20 WCW pump at 1064 nm), MWIR wavelengths ranging from 3.6 to 4.85 mu m are upconverted to near-infrared (NIR) wavelengths (820-870 nm). The NIR light is detected using a standard low...

Conceptual design of a versatile radiation tolerant integrated signal conditioning circuit for resistive sensors

Energy Technology Data Exchange (ETDEWEB)

Leroux, P. [Katholieke Hogeschool Kempen, Kleinhoefstraat 4, B-2440 Geel (Belgium); Katholieke Universiteit Leuven, Dept. ESAT-MICAS, Kasteelpark Arenberg 10, B-3001 Heverlee (Belgium); SCK-CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Sterckx, J. [Katholieke Hogeschool Kempen, Kleinhoefstraat 4, B-2440 Geel (Belgium); Van Uffelen, M.; Damiani, C. [Fusion 4 Energy, Ed. B3, c/Josep, no 2, Torres Diagonal Litoral, 08019 Barcelona (Spain)

2011-07-01

This paper presents the design of a radiation tolerant configurable discrete time CMOS signal conditioning circuit for use with resistive sensors like strain gauge pressure sensors. The circuit is intended to be used for remote handling in harsh environments in the International Thermonuclear Experimental fusion Reactor (ITER). The design features a 5 V differential preamplifier using a Correlated Double Sampling (CDS) architecture at a sample rate of 20 kHz and a 24 V discrete time post amplifier. The gain is digitally controllable between 27 and 400 in the preamplifier and between 1 and 8 in the post amplifier. The nominal input referred noise voltage is only 8.5 {mu}V while consuming only 1 mW. The circuit has a simulated radiation tolerance of more than 1 MGy. (authors)

Radiation effects on active pixel sensors (APS); Effets de l'irradiation sur les capteurs a pixels actifs (APS)

Energy Technology Data Exchange (ETDEWEB)

Cohen, M; David, J P [ONERA-CERT/, 31 - Toulouse (France)

1999-07-01

Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using {sup 60}Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity.

Broadband terahertz spectroscopy: principles, fundamental research and potential for industrial applications

International Nuclear Information System (INIS)

Zouaghi, W; Thomson, M D; Rabia, K; Hahn, R; Blank, V; Roskos, H G

2013-01-01

Terahertz radiation (also called T-rays) can be employed for spectroscopy and imaging, from the laboratory to industrial applications. In this paper we give an overview of how broadband optoelectronic THz techniques (i.e. using optical lasers to achieve THz generation and detection) can be implemented, and give examples of their unique use in solid-state physics, and in biological and industrial applications. (paper)

Study and characterization of an integrated circuit-deposited hydrogenated amorphous silicon sensor for the detection of particles and radiations

International Nuclear Information System (INIS)

Despeisse, M.

2006-03-01

Next generation experiments at the European laboratory of particle physics (CERN) require particle detector alternatives to actual silicon detectors. This thesis presents a novel detector technology, which is based on the deposition of a hydrogenated amorphous silicon sensor on top of an integrated circuit. Performance and limitations of this technology have been assessed for the first time in this thesis in the context of particle detectors. Specific integrated circuits have been designed and the detector segmentation, the interface sensor-chip and the sensor leakage current have been studied in details. The signal induced by the track of an ionizing particle in the sensor has been characterized and results on the signal speed, amplitude and on the sensor resistance to radiation are presented. The results are promising regarding the use of this novel technology for radiation detection, though limitations have been shown for particle physics application. (author)

Microfabricated electrochemical sensor for the detection of radiation-induced DNA damage

Energy Technology Data Exchange (ETDEWEB)

Wang, J.; Rivas, G.; Ozsoz, M.; Grant, D.H.; Cai, X.; Parrado, C. [New Mexico State Univ., Las Cruces, NM (United States)

1997-04-01

An electrochemical biosensor protocol for the detection of radiation-induced DNA damage is described. The procedure employs a dsDNA-coated screen-printed electrode and relies on changes in the guanine-DNA oxidation signal upon exposure to ultraviolet radiation. The decreased signal is ascribed primarily to conformational changes in the DNA and to the photoconversion of the guanine-DNA moiety to a nonelectroactive monomeric base product. Factors influencing the response of these microfabricated DNA sensors, such as irradiation time, wavelength, and distance, are explored, and future prospects are discussed. Similar results are given for the use of bare strip electrodes in connection with irradiated DNA solutions. 8 refs., 4 figs.

Radiation hardness tests of double-sided 3D strip sensors with passing-through columns

Energy Technology Data Exchange (ETDEWEB)

Dalla Betta, Gian-Franco, E-mail: gianfranco.dallabetta@unitn.it [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); INFN TIFPA, Via Sommarive 14, I-38123 Trento (Italy); Betancourt, Christopher [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Boscardin, Maurizio; Giacomini, Gabriele [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive 18, I-38123 Trento (Italy); Jakobs, Karl; Kühn, Susanne [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Lecini, Besnik [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); Mendicino, Roberto [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); INFN TIFPA, Via Sommarive 14, I-38123 Trento (Italy); Mori, Riccardo; Parzefall, Ulrich [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Povoli, Marco [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); Thomas, Maira [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Zorzi, Nicola [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive 18, I-38123 Trento (Italy)

2014-11-21

This paper deals with a radiation hardness study performed on double-sided 3D strip sensors with passing-through columns. Selected results from the characterization of the irradiated sensors with a beta source and a laser setup are reported and compared to pre-irradiation results and to TCAD simulations. The sensor performance in terms of signal efficiency is found to be in good agreement with that of other 3D sensors irradiated at the same fluences and tested under similar experimental conditions. - Highlights: • We report results from 3D silicon strip detectors irradiated up to HL-LHC fluences. • I–V curves, noise, charge collection measurements and laser scans are shown. • In all sensors, signals are distinguished from the noise already at low voltage. • Signal efficiency is in agreement with values expected from the electrode geometry. • Efficiency and spatial uniformity would benefit from higher operation voltages.

Radiation hardness tests of double-sided 3D strip sensors with passing-through columns

International Nuclear Information System (INIS)

Dalla Betta, Gian-Franco; Betancourt, Christopher; Boscardin, Maurizio; Giacomini, Gabriele; Jakobs, Karl; Kühn, Susanne; Lecini, Besnik; Mendicino, Roberto; Mori, Riccardo; Parzefall, Ulrich; Povoli, Marco; Thomas, Maira; Zorzi, Nicola

2014-01-01

This paper deals with a radiation hardness study performed on double-sided 3D strip sensors with passing-through columns. Selected results from the characterization of the irradiated sensors with a beta source and a laser setup are reported and compared to pre-irradiation results and to TCAD simulations. The sensor performance in terms of signal efficiency is found to be in good agreement with that of other 3D sensors irradiated at the same fluences and tested under similar experimental conditions. - Highlights: • We report results from 3D silicon strip detectors irradiated up to HL-LHC fluences. • I–V curves, noise, charge collection measurements and laser scans are shown. • In all sensors, signals are distinguished from the noise already at low voltage. • Signal efficiency is in agreement with values expected from the electrode geometry. • Efficiency and spatial uniformity would benefit from higher operation voltages

Optical cavity-assisted broadband optical transparency of a plasmonic metal film

International Nuclear Information System (INIS)

Liu, Zhengqi; Nie, Yiyou; Yuan, Wen; Liu, Xiaoshan; Huang, Shan; Gao, Huogui; Gu, Gang; Liu, Guiqiang; Chen, Jing

2015-01-01

We theoretically present a powerful method to achieve a continuous metal film structure with broadband optical transparency via introducing a dielectric Fabry–Pérot (FP) cavity. An incident optical field could be efficiently coupled and confined with the strong localized plasmons by the non-close-packed plasmonic crystal at the input part and could then become re-radiated output via the transmission channel supported by the dielectric cavity. The formed photonic-plasmonic system could therefore make the seamless metal film structure have a superior near-unity transparency (up to 97%) response and a broadband transparent spectrum with bandwidth >245 nm (with transmittance >90%) in the optical regime. The observed optical properties of the proposed structure can be highly tuned via varying the structural parameters. Based on the colloidal assembly method, the proposed plasmonic crystal can be fabricated in a large area. In addition, the achieved optical transparency can be retained in the extremely roughed metal film structure. Thereby, the findings could offer a feasible way to achieve a broadband transparent metal film structure and hold potential applications in transparent electrodes, touch screens and interactive electronics. (paper)

Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

CERN Document Server

Ducourthial, Audrey; The ATLAS collaboration

2017-01-01

Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of $10^{15} n_{eq}/cm^2$ and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time. In addition to thoroughly describing the setup, we present first predictions for basic pixel cluster properties alongside...

Modeling radiation damage to pixel sensors in the ATLAS detector

CERN Document Server

Ducourthial, Audrey; The ATLAS collaboration

2017-01-01

Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of $10^{15}n_{eq}/cm^2$ and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time. In addition to thoroughly describing the setup, we present first predictions for basic pixel cluster properties alongside ...

Broadband external cavity quantum cascade laser based sensor for gasoline detection

Science.gov (United States)

Ding, Junya; He, Tianbo; Zhou, Sheng; Li, Jinsong

2018-02-01

A new type of tunable diode spectroscopy sensor based on an external cavity quantum cascade laser (ECQCL) and a quartz crystal tuning fork (QCTF) were used for quantitative analysis of volatile organic compounds. In this work, the sensor system had been tested on different gasoline sample analysis. For signal processing, the self-established interpolation algorithm and multiple linear regression algorithm model were used for quantitative analysis of major volatile organic compounds in gasoline samples. The results were very consistent with that of the standard spectra taken from the Pacific Northwest National Laboratory (PNNL) database. In future, The ECQCL sensor will be used for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis, etc.

Acoustic Emission Behavior of Early Age Concrete Monitored by Embedded Sensors.

Science.gov (United States)

Qin, Lei; Ren, Hong-Wei; Dong, Bi-Qin; Xing, Feng

2014-10-02

Acoustic emission (AE) is capable of monitoring the cracking activities inside materials. In this study, embedded sensors were employed to monitor the AE behavior of early age concrete. Type 1-3 cement-based piezoelectric composites, which had lower mechanical quality factor and acoustic impedance, were fabricated and used to make sensors. Sensors made of the composites illustrated broadband frequency response. In a laboratory, the cracking of early age concrete was monitored to recognize different hydration stages. The sensors were also embedded in a mass concrete foundation to localize the temperature gradient cracks.

Broadband in schools: towards a definition and model of broadband for South African schools

CSIR Research Space (South Africa)

Ford, Merryl

2017-05-01

Full Text Available South Africa is about to provide broadband internet connectivity to all schools in the country via the implementation of the national broadband policy. The challenge is to ensure a balance between the schools’ demand-side usage and supply...

Analysis of the Proposed Ghana Broadband Strategy

DEFF Research Database (Denmark)

Williams, Idongesit; Botwe, Yvonne

This project studied the Ghana Broadband Strategy with the aim of evaluating the recommendations in the strategy side by side the broadband development in Ghana. The researchers conducted interviews both officially and unofficially with ICT stakeholders, made observations, studied Government...... intervention policies recommended in the Ghana broadband policy is used to evaluate the broadband market to find out whether the strategy consolidates with the Strengths and opportunities of the market and whether it corrects the anomalies that necessitate the weaknesses and threats to the market....... The strategy did address some threats and weaknesses of the broadband market. It also consolidated on some strengths and opportunities of the broadband market. The researchers also discovered that a market can actually grow without a policy. But a market will grow faster if a well implemented policy is guiding...

Sensor array signal processing

CERN Document Server

Naidu, Prabhakar S

2009-01-01

Chapter One: An Overview of Wavefields 1.1 Types of Wavefields and the Governing Equations 1.2 Wavefield in open space 1.3 Wavefield in bounded space 1.4 Stochastic wavefield 1.5 Multipath propagation 1.6 Propagation through random medium 1.7 ExercisesChapter Two: Sensor Array Systems 2.1 Uniform linear array (ULA) 2.2 Planar array 2.3 Distributed sensor array 2.4 Broadband sensor array 2.5 Source and sensor arrays 2.6 Multi-component sensor array2.7 ExercisesChapter Three: Frequency Wavenumber Processing 3.1 Digital filters in the w-k domain 3.2 Mapping of 1D into 2D filters 3.3 Multichannel Wiener filters 3.4 Wiener filters for ULA and UCA 3.5 Predictive noise cancellation 3.6 Exercises Chapter Four: Source Localization: Frequency Wavenumber Spectrum4.1 Frequency wavenumber spectrum 4.2 Beamformation 4.3 Capon's w-k spectrum 4.4 Maximum entropy w-k spectrum 4.5 Doppler-Azimuth Processing4.6 ExercisesChapter Five: Source Localization: Subspace Methods 5.1 Subspace methods (Narrowband) 5.2 Subspace methods (B...

Peramalan Pengguna Broadband di Indonesia [Forecasting of Broadband Users in Indonesia

Directory of Open Access Journals (Sweden)

Azwar Aziz

2016-07-01

Full Text Available Negara Indonesia memiliki peluang yang sangat besar untuk merealisasikan potensi pitalebar, mengingat Indonesia memiliki jumlah penduduk 253 juta orang dan pengguna internet 88,1 juta orang pada tahun 2014. Di sisi lain sektor komunikasi (salah satunya termasuk telekomunikasi merupakan satu-satunya sektor yang secara konsisten memberikan kontribusi pertumbuhan terhadap Pendapatan Domestik Bruto (PDB sebesar dua angka (double digit. Kemudian peran penting pemerintah adalah selalu mengantisipasi dalam membuat regulasi telekomunikasi, salah satu nya untuk mempercepat penggelaran prasarana pitalebar, seperti menerbitkan Peraturan Presiden RI. Nomor 96 Tahun 2014 tentang Rencana Pitalebar Indonesia 2014 – 2019.  Secara riil pembangunan jaringan pitalebar di Indonesia masih dilakukan di kota-kota besar, mengingat pengguna telekomunikasi sebagian besar berada di kota-kota besar. Selain itu perangkat hanset atau handphone, ketersediaan di pasaran masih terbatas dan harganya masih mahal. Kajian ini menggunakan metodologi penelitian kuantitatif dengan menghitung peramalan dan kualitatif, dengan melakukan observasi atau pengamatan langsung ke lapangan kepada perusahaan Telkom, Telkomsel, XL Axiata dan Indosat. Selanjutnya hasil penelitian ini diperoleh lima faktor yang mempengaruhi penggunaan pitalebar yaitu jumlah penduduk, produk domestik bruto, pendapatan per kapita, laju pertumbuhan ekonomi dan inflasi, dan laju penetrasi. Selain itu, hasil pitalebar menunjukkan pengguna pitalebar lima tahun kedepan selalu meningkat.*****Indonesia has a tremendous opportunity to implement the potential of broadband, as Indonesia has a population of 253 million people and 88.1 million Internet users in 2014. On the other hand, the communication sector (one of them including telecommunications is the only sector that is consistently contributed to the growth of Gross Domestic Product (GDP as many as two numbers (double-digit. Then the important role of government is

Broadband plasmon induced transparency in terahertz metamaterials

International Nuclear Information System (INIS)

Zhu Zhihua; Yang Xu; Gu Jianqiang; Jiang Jun; Tian Zhen; Han Jiaguang; Zhang Weili; Yue Weisheng; Tonouchi, Masayoshi

2013-01-01

Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. (paper)

Response to long-period seismic waves recorded by broadband seismometer and pore pressure sensor at IODP Site C0002, Nankai Trough

Science.gov (United States)

Kitada, K.; Araki, E.; Kimura, T.; Saffer, D. M.

2013-12-01

Long term in situ monitoring of seismic activity, slow slip event, and pore fluid behavior around mega earthquake zone is important for understanding the processes of earthquake generation and strain accumulation. In order to characterize the response to long-period seismic waves, we compared waveforms and hydroseismograms recorded by broadband seismometer and pore pressure transducers, respectively, which were installed at IODP Site C0002 in the Nankai Trough Kumano Basin. The borehole monitoring system sensor array at Site C0002 is designed to collect multiparameter observations covering a dynamic range of events, including local microearthquakes, low frequency earthquakes, and large-scale earthquakes similar to the Tonankai earthquake. The suite of sensors for the downhole portion of the observatory includes a broadband seismometer (CMG3TBD, Guralp Systems Ltd.) with sampling rate of 100Hz at the depth of 907mbsf, and four pressure ports connected to pressure gauges located at 948mbsf, 917mbsf, 766mbsf, and at the seafloor. The sampling rate of the data logger was set to 1Hz after successful connection to the DONET seafloor cable network for real-time monitoring on 24 Jan 2013. Since then, we processed 12 earthquakes between a moment magnitude of 6.5 to 8.3. In addition to the comparison of long-period surface waves waveform and pressure data, we compared the records with theoretical strain seismograms. The latter were calculated by normal mode summation using the earth model PREM of Dziewonski and Anderson (1981). A Butterworth bandpass filter was applied to the records with cut-off frequencies of 0.003 and 0.1 Hz. Our initial results indicate that the hydroseismograms correspond well with the vertical rather than the horizontal (radial and transverse) components in seismic data. The observed hydroseismogram have a good correlation with the predicted volumetric strain seismogram, especially for the Okhotsk (2013/05/24 14:17UT, Mw8.3, 632km depth), the Chishima

Water quality sensor

International Nuclear Information System (INIS)

Ishizuka, Keiko; Takahashi, Masanori; Watanabe, Atsushi; Ibe, Hidefumi.

1994-01-01

The sensor of the present invention can directly measure oxygen/hydrogen peroxide concentrations in reactor water under radiation irradiation condition, and it has a long life time. Namely, an oxygen sensor comprises electrodes attached on both sides of high temperature/radiation resistant ion conductive material in which ions are sufficiently diffused within a temperature range of from a room temperature to 300degC. It has a performance for measuring electromotive force caused by the difference of a partial pressure between a reference gas and a gas to be measured contained in the high temperature/radiation resistant material. A hydrogen peroxide sensor has the oxygen sensor described above, to which a filter for causing decomposition of hydrogen peroxide is attached. The sensor of the present invention can directly measure oxygen/hydrogen peroxide concentrations in a reactor water of a BWR type reactor under high temperature/radiation irradiation condition. Accordingly, accurate water quality environment in the reactor water can be recognized. As a result, determination of incore corrosion environment is established thereby enabling to attain reactor integrity, safety and long life. (I.S.)

47 CFR 27.1305 - Shared wireless broadband network.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Shared wireless broadband network. 27.1305... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

47 CFR 90.1405 - Shared wireless broadband network.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Shared wireless broadband network. 90.1405... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

Beta particle detection efficiency of the radiation sensor made from a mixture of polyaniline and titanium oxide

International Nuclear Information System (INIS)

Tamura, M.; Miyata, H.; Katsumata, M.; Matsuda, K.; Ueno, T.; Ito, D.; Suzuki, T.

2016-01-01

We developed a new real-time radiation sensor using an organic semiconductor and measured its β-particle detection sensitivity. This sensor is fabricated by simply combining a p-type semiconductor, polyaniline (Pani), with an n-type semiconductor, TiO_2, and processing the compound. Since Pani and TiO_2 are both inexpensive materials, the sensor can be fabricated at a lower cost than inorganic semiconductor sensors. The signal of each fabricated sensor was measured by a charge sensitive ADC for the irradiation of β-particles. The response signal data of the ADC for each irradiation was measured to calculate the detection efficiency of the detector. The maximum detection efficiency measured as β-particle sensitivity of the sensor was 1%. This β-particle sensitivity is higher than that reported of Pani sensors in the past.

Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

CERN Document Server

Nachman, Benjamin Philip; The ATLAS collaboration

2017-01-01

Silicon Pixel detectors are at the core of the current and planned upgrade of the ATLAS detector. As the detector in closest proximity to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the HL-LHC, the innermost layers will receive a fluence in excess of $10^{15}$ 1 MeV $n_\\mathrm{eq}/\\mathrm{cm}^2$ and the HL-LHC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. This talk presents a digitization model that includes radiation damage effects to the ATLAS Pixel sensors for the first time. After a thorough description of the setup, predictions for basic Pixel cluster properties are presented alongside first validation studies with Run 2 collision data.

The use of antenna radiation pattern in node localisation algorithms for wireless sensor networks

CSIR Research Space (South Africa)

Mwila, MK

2014-08-01

Full Text Available due to the limited accuracy inherent to the current ranging model. These models, however, make the assumption that the antenna radiation pattern is omnidirectional targeted to simplifying the complexity of the algorithms. An increasing number of sensor...

Studies of radiation damage in silicon sensors and a measurement of the inelastic proton--proton cross-section at 13 TeV

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00360674; Ward, Patricia

This thesis presents studies of radiation damage in silicon sensors for the new ATLAS tracker at the high-luminosity LHC, calibrations of the LHC luminosity scale, and a measurement of the proton--proton inelastic cross-section at 13 TeV~with ATLAS data. The studies of radiation damage are performed by comparing sensor performance before and after irradiation, and include annealing studies. The measured quantities include: leakage current, depletion depth, inter-strip isolation, and charge collection. Surface and bulk damage is studied by comparing the results of sensors irradiated with protons and neutrons. The observed degradation of performance suggests the current sensor design will endure the radiation damage expected over the lifetime of the experiment at the high-luminosity LHC. The luminosity is calibrated for the proton--proton, proton--lead, and lead--lead collisions delivered by the LHC during 2013 and 2015. The absolute luminosity scale is derived with the van der Meer method. The systematic unc...

Radiation effects on active pixel sensors (APS); Effets de l'irradiation sur les capteurs a pixels actifs (APS)

Energy Technology Data Exchange (ETDEWEB)

Cohen, M.; David, J.P. [ONERA-CERT/, 31 - Toulouse (France)

1999-07-01

Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using {sup 60}Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity.

P-stop isolation study of irradiated n-in-p type silicon strip sensors for harsh radiation environment

CERN Document Server

AUTHOR|(CDS)2084505

2015-01-01

In order to determine the most radiation hard silicon sensors for the CMS Experiment after the Phase II Upgrade in 2023 a comprehensive study of silicon sensors after a fluence of up to $1.5\\times10^{15} n_{eq}/cm^{2}$ corresponding to $3000 fb^{-1}$ after the HL-LHC era has been carried out. The results led to the decision that the future Outer Tracker (20~cm${<}R{<}$110~cm) of CMS will consist of n-in-p type sensors. This technology is more radiation hard but also the manufacturing is more challenging compared to p-in-n type sensors due to additional process steps in order to suppress the accumulation of electrons between the readout strips. One possible isolation technique of adjacent strips is the p-stop structure which is a p-type material implantation with a certain pattern for each individual strip. However, electrical breakdown and charge collection studies indicate that the process parameters of the p-stop structure have to be carefully calibrated in order to achieve a sufficient strip isolatio...

Intense, broadband, pulsed I-R source at the National Synchrotron Light Source

International Nuclear Information System (INIS)

Williams, G.P.

1984-01-01

We describe a broadband (1 μm to 1 mm) synchrotron radiation infrared source, pulsed each 20 to 180 nseconds and delivering about 10 15 photons/sec/1% bandpass into f10 optics. The source size is diffraction limited. This source is thus 100 to 1000 times brighter than a 2000 0 K black body, very stable and capable of being used for calibration

Broadband electromagnetic environments simulator (EMES)

International Nuclear Information System (INIS)

Pollard, N.

1977-01-01

A new test facility has been developed by Sandia Laboratories for determining the effects of electromagnetic environments on systems and components. The facility is capable of producing uniform, vertically polarized, continuous wave (CW) and pulsed fields over the frequency range of dc to 10 GHz. This broadband capability addresses the electromagnetic radiation (EMR) threat and is ideally suited to computer controlled sweeping and data acquisition. EMES is also capable of producing uniform transient fields having the wave shape and magnitude characteristic of a nuclear electromagnetic pulse (EMP) and near lightning. The design consists of a truncated, triplate, rectangular coaxial transmission line. The spacing between the flat center conductor and the ground planes is 4 meters. The line is terminated in its characteristic impedance of 50 ohms. At frequencies below the first resonance of the facility it behaves as a typical coaxial system. Above resonance, a wall of electromagnetic absorbing material provides a nonreflecting termination. Thus, EMES essentially combines the elements of a transmission line and an anechoic chamber. It will not radiate electromagnetic energy into the surrounding area because it is a shielded transmission line

Missing Data Imputation of Solar Radiation Data under Different Atmospheric Conditions

Science.gov (United States)

Turrado, Concepción Crespo; López, María del Carmen Meizoso; Lasheras, Fernando Sánchez; Gómez, Benigno Antonio Rodríguez; Rollé, José Luis Calvo; de Cos Juez, Francisco Javier

2014-01-01

Global solar broadband irradiance on a planar surface is measured at weather stations by pyranometers. In the case of the present research, solar radiation values from nine meteorological stations of the MeteoGalicia real-time observational network, captured and stored every ten minutes, are considered. In this kind of record, the lack of data and/or the presence of wrong values adversely affects any time series study. Consequently, when this occurs, a data imputation process must be performed in order to replace missing data with estimated values. This paper aims to evaluate the multivariate imputation of ten-minute scale data by means of the chained equations method (MICE). This method allows the network itself to impute the missing or wrong data of a solar radiation sensor, by using either all or just a group of the measurements of the remaining sensors. Very good results have been obtained with the MICE method in comparison with other methods employed in this field such as Inverse Distance Weighting (IDW) and Multiple Linear Regression (MLR). The average RMSE value of the predictions for the MICE algorithm was 13.37% while that for the MLR it was 28.19%, and 31.68% for the IDW. PMID:25356644

Missing Data Imputation of Solar Radiation Data under Different Atmospheric Conditions

Directory of Open Access Journals (Sweden)

Concepción Crespo Turrado

2014-10-01

Full Text Available Global solar broadband irradiance on a planar surface is measured at weather stations by pyranometers. In the case of the present research, solar radiation values from nine meteorological stations of the MeteoGalicia real-time observational network, captured and stored every ten minutes, are considered. In this kind of record, the lack of data and/or the presence of wrong values adversely affects any time series study. Consequently, when this occurs, a data imputation process must be performed in order to replace missing data with estimated values. This paper aims to evaluate the multivariate imputation of ten-minute scale data by means of the chained equations method (MICE. This method allows the network itself to impute the missing or wrong data of a solar radiation sensor, by using either all or just a group of the measurements of the remaining sensors. Very good results have been obtained with the MICE method in comparison with other methods employed in this field such as Inverse Distance Weighting (IDW and Multiple Linear Regression (MLR. The average RMSE value of the predictions for the MICE algorithm was 13.37% while that for the MLR it was 28.19%, and 31.68% for the IDW.

Missing data imputation of solar radiation data under different atmospheric conditions.

Science.gov (United States)

Turrado, Concepción Crespo; López, María Del Carmen Meizoso; Lasheras, Fernando Sánchez; Gómez, Benigno Antonio Rodríguez; Rollé, José Luis Calvo; Juez, Francisco Javier de Cos

2014-10-29

Global solar broadband irradiance on a planar surface is measured at weather stations by pyranometers. In the case of the present research, solar radiation values from nine meteorological stations of the MeteoGalicia real-time observational network, captured and stored every ten minutes, are considered. In this kind of record, the lack of data and/or the presence of wrong values adversely affects any time series study. Consequently, when this occurs, a data imputation process must be performed in order to replace missing data with estimated values. This paper aims to evaluate the multivariate imputation of ten-minute scale data by means of the chained equations method (MICE). This method allows the network itself to impute the missing or wrong data of a solar radiation sensor, by using either all or just a group of the measurements of the remaining sensors. Very good results have been obtained with the MICE method in comparison with other methods employed in this field such as Inverse Distance Weighting (IDW) and Multiple Linear Regression (MLR). The average RMSE value of the predictions for the MICE algorithm was 13.37% while that for the MLR it was 28.19%, and 31.68% for the IDW.

Modeling radiation damage to pixel sensors in the ATLAS detector

Science.gov (United States)

Ducourthial, A.

2018-03-01

Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC) . As the closest detector component to the interaction point, these detectors will be subject to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC) [1], the innermost layers will receive a fluence in excess of 1015 neq/cm2 and the HL-LHC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is essential in order to make accurate predictions for current and future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects on the ATLAS pixel sensors for the first time. In addition to thoroughly describing the setup, we present first predictions for basic pixel cluster properties alongside early studies with LHC Run 2 proton-proton collision data.

Exposure estimates based on broadband elf magnetic field measurements versus the ICNIRP multiple frequency rule

International Nuclear Information System (INIS)

Paniagua, Jesus M.; Rufo, Montana; Jimenez, Antonio; Pachon, Fernando T.; Carrero, Julian

2015-01-01

The evaluation of exposure to extremely low-frequency (ELF) magnetic fields using broadband measurement techniques gives satisfactory results when the field has essentially a single frequency. Nevertheless, magnetic fields are in most cases distorted by harmonic components. This work analyses the harmonic components of the ELF magnetic field in an outdoor urban context and compares the evaluation of the exposure based on broadband measurements with that based on spectral analysis. The multiple frequency rule of the International Commission on Non-ionizing Radiation Protection (ICNIRP) regulatory guidelines was applied. With the 1998 ICNIRP guideline, harmonics dominated the exposure with a 55 % contribution. With the 2010 ICNIRP guideline, however, the primary frequency dominated the exposure with a 78 % contribution. Values of the exposure based on spectral analysis were significantly higher than those based on broadband measurements. Hence, it is clearly necessary to determine the harmonic components of the ELF magnetic field to assess exposure in urban contexts. (authors)

Radiation hard 3D diamond sensors for vertex detectors at HL-LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00336619; Quadt, Arnulf; Grosse-Knetter, Jörn; Weingarten, Jens

Diamond is a good candidate to replace silicon as sensor material in the innermost layer of a tracking detector at HL-LHC, due to its high radiation tolerance. After particle fluences of $10^{16}\\,{\\rm protons/cm^2}$, diamond sensors are expected to achieve a higher signal to noise ratio than silicon. In order to use low grade polycrystalline diamonds as sensors, electrodes inside the diamond bulk, so called 3D electrodes, are produced. Typically, this kind of diamond material has a lower charge collection distance (CCD) than higher grade diamond, which results in a decreased signal amplitude. With 3D electrodes it is possible to achieve full charge collection even in samples with low CCDs by decoupling the spacing of the electrodes from the thickness of the diamond bulk. The electrodes are produced using a femtosecond laser, which changes the phase of the diamond material. The phase changed material is conductive and identified as nanocrystalline graphite using Raman spectroscopy. Due to a crater like struct...

Methodology Development for SiC Sensor Signal Modelling in the Nuclear Reactor Radiation Environments

International Nuclear Information System (INIS)

Cetnar, J.; Krolikowski, I.P.

2013-06-01

This paper deals with SiC detector simulation methodology for signal formation by neutrons and induced secondary radiation as well as its inverse interpretation. The primary goal is to achieve the SiC capability of simultaneous spectroscopic measurements of neutrons and gamma-rays for which an appropriate methodology of the detector signal modelling and its interpretation must be adopted. The process of detector simulation is divided into two basically separate but actually interconnected sections. The first one is the forward simulation of detector signal formation in the field of the primary neutron and secondary radiations, whereas the second one is the inverse problem of finding a representation of the primary radiation, based on the measured detector signals. The applied methodology under development is based on the Monte Carlo description of radiation transport and analysis of the reactor physics. The methodology of SiC detector signal interpretation will be based on the existing experience in neutron metrology developed in the past for various neutron and gamma-ray detection systems. Since the novel sensors based on SiC are characterised by a new structure, yet to be finally designed, the methodology for particle spectroscopic fluence measurement must be developed while giving a productive feed back to the designing process of SiC sensor, in order to arrive at the best possible design. (authors)

Broadband near-infrared metamaterial absorbers utilizing highly lossy metals

DEFF Research Database (Denmark)

Ding, Fei; Dai, Jin; Chen, Yiting

2016-01-01

Radiation absorbers have increasingly been attracting attention as crucial components for controllable thermal emission, energy harvesting, modulators, etc. However, it is still challenging to realize thin absorbers which can operate over a wide spectrum range. Here, we propose and experimentally...... demonstrate thin, broadband, polarization-insensitive and omnidirectional absorbers working in the near-infrared range. We choose titanium (Ti) instead of the commonly used gold (Au) to construct nano-disk arrays on the top of a silicon dioxide (SiO2) coated Au substrate, with the quality (Q) factor...

Broadband acoustic properties of a murine skull.

Science.gov (United States)

Estrada, Héctor; Rebling, Johannes; Turner, Jake; Razansky, Daniel

2016-03-07

It has been well recognized that the presence of a skull imposes harsh restrictions on the use of ultrasound and optoacoustic techniques in the study, treatment and modulation of the brain function. We propose a rigorous modeling and experimental methodology for estimating the insertion loss and the elastic constants of the skull over a wide range of frequencies and incidence angles. A point-source-like excitation of ultrawideband acoustic radiation was induced via the absorption of nanosecond duration laser pulses by a 20 μm diameter microsphere. The acoustic waves transmitted through the skull are recorded by a broadband, spherically focused ultrasound transducer. A coregistered pulse-echo ultrasound scan is subsequently performed to provide accurate skull geometry to be fed into an acoustic transmission model represented in an angular spectrum domain. The modeling predictions were validated by measurements taken from a glass cover-slip and ex vivo adult mouse skulls. The flexible semi-analytical formulation of the model allows for seamless extension to other transducer geometries and diverse experimental scenarios involving broadband acoustic transmission through locally flat solid structures. It is anticipated that accurate quantification and modeling of the skull transmission effects would ultimately allow for skull aberration correction in a broad variety of applications employing transcranial detection or transmission of high frequency ultrasound.

Clementine sensor suite

Energy Technology Data Exchange (ETDEWEB)

Ledebuhr, A.G. [Lawrence Livermore National Lab., CA (United States)

1994-11-15

LLNL designed and built the suite of six miniaturized light-weight space-qualified sensors utilized in the Clementine mission. A major goal of the Clementine program was to demonstrate technologies originally developed for Ballistic Missile Defense Organization Programs. These sensors were modified to gather data from the moon. This overview presents each of these sensors and some preliminary on-orbit performance estimates. The basic subsystems of these sensors include optical baffles to reject off-axis stray light, light-weight ruggedized optical systems, filter wheel assemblies, radiation tolerant focal plane arrays, radiation hardened control and readout electronics and low mass and power mechanical cryogenic coolers for the infrared sensors. Descriptions of each sensor type are given along with design specifications, photographs and on-orbit data collected.

Radiation Damage Modeling for 3D Pixel Sensors in the ATLAS Detector

CERN Document Server

Wallangen, Veronica; The ATLAS collaboration

2017-01-01

Silicon Pixel detectors are at the core of the current and planned upgrade of the ATLAS detector. As the detector in closest proximity to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the HL-LHC, the innermost layers will receive a fluence in excess of 10^15 neq/cm2 and the HL-LHC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. This poster presents the details of a new digitization model that includes radiation damage effects to the 3D Pixel sensors for the ATLAS Detector.

Principles of broadband switching and networking

CERN Document Server

Liew, Soung C

2010-01-01

An authoritative introduction to the roles of switching and transmission in broadband integrated services networks Principles of Broadband Switching and Networking explains the design and analysis of switch architectures suitable for broadband integrated services networks, emphasizing packet-switched interconnection networks with distributed routing algorithms. The text examines the mathematical properties of these networks, rather than specific implementation technologies. Although the pedagogical explanations in this book are in the context of switches, many of the fundamenta

Broadband plasmon induced transparency in terahertz metamaterials

KAUST Repository

Zhu, Zhihua

2013-04-25

Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. © 2013 IOP Publishing Ltd.

Underresolved absorption spectroscopy of OH radicals in flames using broadband UV LEDs

Science.gov (United States)

White, Logan; Gamba, Mirko

2018-04-01

A broadband absorption spectroscopy diagnostic based on underresolution of the spectral absorption lines is evaluated for the inference of species mole fraction and temperature in combustion systems from spectral fitting. The approach uses spectrally broadband UV light emitting diodes and leverages low resolution, small form factor spectrometers. Through this combination, the method can be used to develop high precision measurement sensors. The challenges of underresolved spectroscopy are explored and addressed using spectral derivative fitting, which is found to generate measurements with high precision and accuracy. The diagnostic is demonstrated with experimental measurements of gas temperature and OH mole fraction in atmospheric air/methane premixed laminar flat flames. Measurements exhibit high precision, good agreement with 1-D flame simulations, and high repeatability. A newly developed model of uncertainty in underresolved spectroscopy is applied to estimate two-dimensional confidence regions for the measurements. The results of the uncertainty analysis indicate that the errors in the outputs of the spectral fitting procedure are correlated. The implications of the correlation between uncertainties for measurement interpretation are discussed.

Models of the Dynamics of Spatially Separated Broadband Electromagnetic Fields Interacting with Resonant Atoms

Science.gov (United States)

Basharov, A. M.

2018-03-01

The Markov model of spontaneous emission of an atom localized in a spatial region with a broadband electromagnetic field with zero photon density is considered in the conditions of coupling of the electromagnetic field with the broadband field of a neighboring space. The evolution operator of the system and the kinetic equation for the atom are obtained. It is shown that the field coupling constant affects the rate of spontaneous emission of the atom, but is not manifested in the atomic frequency shift. The analytic expression for the radiative decay constant for the atom is found to be analogous in a certain sense to the expression for the decay constant for a singly excited localized ensemble of identical atoms in the conditions when the effect of stabilization of its excited state by the Stark interaction with the vacuum broadband electromagnetic field is manifested. The model is formulated based on quantum stochastic differential equations of the non- Wiener type and the generalized algebra of the Ito differential of quantum random processes.

"Radiative Closure Studies for Clear Skies During the ARM 2003 Aerosol Intensive Observation Period"

Energy Technology Data Exchange (ETDEWEB)

J. J. Michalsky, G. P. Anderson, J. Barnard, J. Delamere, C. Gueymard, S. Kato, P. Kiedron, A. McComiskey, and P. Ricchiazzi

2006-04-01

The Department of Energy's Atmospheric Radiation Measurement (ARM) program sponsored a large intensive observation period (IOP) to study aerosol during the month of May 2003 around the Southern Great Plains (SGP) Climate Research Facility (CRF) in north central Oklahoma. Redundant measurements of aerosol optical properties were made using different techniques at the surface as well as in vertical profile with sensors aboard two aircraft. One of the principal motivations for this experiment was to resolve the disagreement between models and measurements of diffuse horizontal broadband shortwave irradiance at the surface, especially for modest aerosol loading. This paper focuses on using the redundant aerosol and radiation measurements during this IOP to compare direct beam and diffuse horizontal broadband shortwave irradiance measurements and models at the surface for a wide range of aerosol cases that occurred during 30 clear-sky periods on 13 days of May 2003. Models and measurements are compared over a large range of solar-zenith angles. Six different models are used to assess the relative agreement among them and the measurements. Better agreement than previously achieved appears to be the result of better specification of input parameters and better measurements of irradiances than in prior studies. Biases between modeled and measured direct irradiances are less than 1%, and biases between modeled and measured diffuse irradiances are less than 2%.

Measurement of the environmental broadband electromagnetic waves in a mid-size European city.

Science.gov (United States)

Fernández-García, R; Gil, I

2017-10-01

In this paper, the level of exposure to broadband radiofrequency electromagnetic field in a mid-size European city was evaluated in accordance with the International Commission on Non-ionizing Radiation Protection guidelines from 1998. With the aim to analyse all the potential electromagnetic waves present in the city up to 18GHz, a total of 271 locations distributed along Terrassa (Spain) have been measured. To show the results in an easy-to-interpret way by the citizen, the results have been represented in a set of raster maps. The measurement results obtained showed that the electromagnetic wave measured in all broadband frequency range along the city is much lower than the safety level according to the international regulations for both public and occupational sectors. Copyright © 2017 Elsevier Inc. All rights reserved.

Methods and apparatuses for detection of radiation with semiconductor image sensors

Science.gov (United States)

Cogliati, Joshua Joseph

2018-04-10

A semiconductor image sensor is repeatedly exposed to high-energy photons while a visible light obstructer is in place to block visible light from impinging on the sensor to generate a set of images from the exposures. A composite image is generated from the set of images with common noise substantially removed so the composite image includes image information corresponding to radiated pixels that absorbed at least some energy from the high-energy photons. The composite image is processed to determine a set of bright points in the composite image, each bright point being above a first threshold. The set of bright points is processed to identify lines with two or more bright points that include pixels therebetween that are above a second threshold and identify a presence of the high-energy particles responsive to a number of lines.

Apparatus for accurately measuring high temperatures

Science.gov (United States)

Smith, D.D.

The present invention is a thermometer used for measuring furnace temperatures in the range of about 1800/sup 0/ to 2700/sup 0/C. The thermometer comprises a broadband multicolor thermal radiation sensor positioned to be in optical alignment with the end of a blackbody sight tube extending into the furnace. A valve-shutter arrangement is positioned between the radiation sensor and the sight tube and a chamber for containing a charge of high pressure gas is positioned between the valve-shutter arrangement and the radiation sensor. A momentary opening of the valve shutter arrangement allows a pulse of the high gas to purge the sight tube of air-borne thermal radiation contaminants which permits the radiation sensor to accurately measure the thermal radiation emanating from the end of the sight tube.

Sensors, Volume 4, Thermal Sensors

Science.gov (United States)

Scholz, Jorg; Ricolfi, Teresio

1996-12-01

'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume describes the construction and applicational aspects of thermal sensors while presenting a rigorous treatment of the underlying physical principles. It provides a unique overview of the various categories of sensors as well as of specific groups, e.g. temperature sensors (resistance thermometers, thermocouples, and radiation thermometers), noise and acoustic thermometers, heat-flow and mass-flow sensors. Specific facettes of applications are presented by specialists from different fields including process control, automotive technology and cryogenics. This volume is an indispensable reference work and text book for both specialists and newcomers, researchers and developers.

Advent of broadband public-switched communications

Science.gov (United States)

Casey, John J.

1992-02-01

Advances in data communications infrastructure, display technology, and man-machine interfaces have changed business applications and the requirements of public network data transport. These changes have created opportunities for a new generation of public broadband services to more efficiently extend high speed communications capabilities beyond the customer premises. This paper provides a view of the technology and market evolution of these public broadband data communications services, and suggests early customer networked applications that justify the deployment of a public switched broadband network infrastructure.

Customer Churn Prediction for Broadband Internet Services

Science.gov (United States)

Huang, B. Q.; Kechadi, M.-T.; Buckley, B.

Although churn prediction has been an area of research in the voice branch of telecommunications services, more focused studies on the huge growth area of Broadband Internet services are limited. Therefore, this paper presents a new set of features for broadband Internet customer churn prediction, based on Henley segments, the broadband usage, dial types, the spend of dial-up, line-information, bill and payment information, account information. Then the four prediction techniques (Logistic Regressions, Decision Trees, Multilayer Perceptron Neural Networks and Support Vector Machines) are applied in customer churn, based on the new features. Finally, the evaluation of new features and a comparative analysis of the predictors are made for broadband customer churn prediction. The experimental results show that the new features with these four modelling techniques are efficient for customer churn prediction in the broadband service field.

Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

Science.gov (United States)

Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

2016-06-01

A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

Extending Wireless Broadband Network Architectures with Home Gateways, Localization, and Physical Environment Surveillance

DEFF Research Database (Denmark)

Jelling Kristoffersen, Kåre; Kjærgaard, Mikkel Baun; Chen, Jianjun

2005-01-01

homes. It must bridge across the most prevalent standard protocols for data, video, telephony and telemetry, and must be able to automatically discover new devices in a residence and allow over the air/wire provisioning, billing, management and aggregation of new services from multiple service providers...... is initially demonstrated in a 52 DECT base station installation covering four office buildings of total 4500 m2 . Finally the paper proposes the application of a commercial off-the-shelf wireless broadband network as a sensor network, without any additional hardware, for physical intrusion detection of e...

Standards development for fiber optic spectroscopic components for adverse environments

Science.gov (United States)

Saggese, Steven J.; Greenwell, Roger A.

1994-09-01

Optical fiber sensors are finding wider use in all types of applications involving adverse environments, including exposure to radiation. In order to effectively characterize and evaluate the performance of a fiber sensor system for a radiation environment, such as within a nuclear power plant or in a radioactive waste storage/disposal facility, it is beneficial to develop standard test procedures. Science & Engineering Associates (SEA) has developed two such procedures for the American Society for Testing and Materials (ASTM) which address the testing of optical fibers for remote Raman spectroscopic and broadband sensor applications in a steady state radiation environment.

Broadband Radio Service (BRS) and Educational Broadband Service (EBS) Transmitters

Data.gov (United States)

Department of Homeland Security — The Broadband Radio Service (BRS), formerly known as the Multipoint Distribution Service (MDS)/Multichannel Multipoint Distribution Service (MMDS), is a commercial...

A radiation-hardened two transistor memory cell for monolithic active pixel sensors in STAR experiment

International Nuclear Information System (INIS)

Wei, X; Dorokhov, A; Hu, Y; Gao, D

2011-01-01

Radiation tolerance of Monolithic Active Pixel Sensors (MAPS) is dramatically decreased when intellectual property (IP) memories are integrated for fast readout application. This paper presents a new solution to improve radiation hardness and avoid latch-up for memory cell design. The tradeoffs among radiation tolerance, area and speed are significantly considered and analyzed. The cell designed in 0.35 μm process satisfies the radiation tolerance requirements of STAR experiment. The cell size is 4.55 x 5.45 μm 2 . This cell is smaller than the IP memory cell based on the same process and is only 26% of a radiation tolerant 6T SRAM cell used in previous contribution. The write access time of the cell is less than 2 ns, while the read access time is 80 ns.

Networked Sensor Arrays

International Nuclear Information System (INIS)

Tighe, R. J.

2002-01-01

A set of independent radiation sensors, coupled with real-time data telemetry, offers the opportunity to run correlation algorithms for the sensor array as well as to incorporate non-radiological data into the system. This may enhance the overall sensitivity of the sensors and provide an opportunity to project the location of a source within the array. In collaboration with Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL), we have conducted field experiments to test a prototype system. Combining the outputs of a set of distributed sensors permits the correlation that the independent sensor outputs. Combined with additional information such as traffic patterns and velocities, this can reduce random/false detections and enhance detection capability. The principle components of such a system include: (1) A set of radiation sensors. These may be of varying type and complexity, including gamma and/or neutron detectors, gross count and spectral-capable sensors, and low to high energy-resolution sensors. (2) A set of non-radiation sensors. These may include sensors such as vehicle presence and imaging sensors. (3) A communications architecture for near real-time telemetry. Depending upon existing infrastructure and bandwidth requirements, this may be a radio or hard-wire based system. (4) A central command console to pole the sensors, correlate their output, and display the data in a meaningful form to the system operator. Both sensitivity and selectivity are important considerations when evaluating the performance of a detection system. Depending on the application, the optimization of sensitivity as well as the rejection of ''nuisance'' radioactive sources may or may not be critical

The Integrated Radiation Mapper Assistant

Energy Technology Data Exchange (ETDEWEB)

Carlton, R.E.; Tripp, L.R. [Odetics, Inc., Anaheim, CA (United States)

1995-03-01

The Integrated Radiation Mapper Assistant (IRMA) system combines state-of-the-art radiation sensors and microprocessor based analysis techniques to perform radiation surveys. Control of the survey function is from a control station located outside the radiation thus reducing time spent in radiation areas performing radiation surveys. The system consists of a directional radiation sensor, a laser range finder, two area radiation sensors, and a video camera mounted on a pan and tilt platform. THis sensor package is deployable on a remotely operated vehicle. The outputs of the system are radiation intensity maps identifying both radiation source intensities and radiation levels throughout the room being surveyed. After completion of the survey, the data can be removed from the control station computer for further analysis or archiving.

Chaos-assisted broadband momentum transformation in optical microresonators

Science.gov (United States)

Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

2017-10-01

The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks.

An Improved Measurement Method for the Strength of Radiation of Reflective Beam in an Industrial Optical Sensor Based on Laser Displacement Meter.

Science.gov (United States)

Bae, Youngchul

2016-05-23

An optical sensor such as a laser range finder (LRF) or laser displacement meter (LDM) uses reflected and returned laser beam from a target. The optical sensor has been mainly used to measure the distance between a launch position and the target. However, optical sensor based LRF and LDM have numerous and various errors such as statistical errors, drift errors, cyclic errors, alignment errors and slope errors. Among these errors, an alignment error that contains measurement error for the strength of radiation of returned laser beam from the target is the most serious error in industrial optical sensors. It is caused by the dependence of the measurement offset upon the strength of radiation of returned beam incident upon the focusing lens from the target. In this paper, in order to solve these problems, we propose a novel method for the measurement of the output of direct current (DC) voltage that is proportional to the strength of radiation of returned laser beam in the received avalanche photo diode (APD) circuit. We implemented a measuring circuit that is able to provide an exact measurement of reflected laser beam. By using the proposed method, we can measure the intensity or strength of radiation of laser beam in real time and with a high degree of precision.

Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures

KAUST Repository

Yu, Zongfu

2012-10-01

The coupling between free space radiation and optical media critically influences the performance of optical devices. We show that, for any given photonic structure, the sum of the external coupling rates for all its optical modes are subject to an upper bound dictated by the second law of thermodynamics. Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar absorbers. © 2012 American Physical Society.

Test beam evaluation of newly developed n-in-p planar pixel sensors for use in a high radiation environment

Energy Technology Data Exchange (ETDEWEB)

Kimura, K., E-mail: kimihiko@hep.phys.titech.ac.jp [Institute of Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551 (Japan); Yamaguchi, D.; Motohashi, K. [Institute of Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551 (Japan); Nakamura, K.; Unno, Y. [Institute of Particle and Nuclear Study, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Jinnouchi, O. [Institute of Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551 (Japan); Altenheiner, S. [Experimentelle Physik IV, Technische Universität Dortmund, 44221 Dortmund (Germany); Blue, A. [School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, Scotland (United Kingdom); Bomben, M. [CNRS/IN2P3 (France); Laboratoire de physique nucléaire et de hautes energies (LPNHE), Univ. Paris-UMPC, 4 Place Jussieu, 75005 Paris (France); Univ. Paris Diderot (France); Butter, A. [LAL, University Paris-Sud (France); CNRS/IN2P3 (France); Université Paris-Saclay, Orsay (France); Cervelli, A. [Universität Bern, Laboratory for High Energy Physics, Sidlerstrasse 55, CH-3012 Bern (Switzerland); Crawley, S. [School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, Scotland (United Kingdom); Ducourthial, A. [CNRS/IN2P3 (France); Laboratoire de physique nucléaire et de hautes energies (LPNHE), Univ. Paris-UMPC, 4 Place Jussieu, 75005 Paris (France); Univ. Paris Diderot (France); Gisen, A. [Experimentelle Physik IV, Technische Universität Dortmund, 44221 Dortmund (Germany); Hagihara, M. [Institute of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8751 (Japan); and others

2016-09-21

Radiation-tolerant n-in-p planar pixel sensors have been under development in cooperation with Hamamatsu Photonics K.K. (HPK). This is geared towards applications in high-radiation environments, such as for the future Inner Tracker (ITk) placed in the innermost part of the ATLAS detector in the high luminosity LHC (HL-LHC) experiment. Prototypes of those sensors have been produced, irradiated, and evaluated over the last few years. In the previous studies, it was reported that significant drops in the detection efficiency were observed after irradiation, especially under bias structures. The bias structures are made up of poly-Si or Al bias rails and poly-Si bias resistors. The structure is implemented on the sensors to allow quality checks to be performed before the bump-bonding process, and to ensure that charge generated in floating pixels due to non-contacting or missing bump-bonds is dumped in a controlled way in order to avoid noise. To minimize the efficiency drop, several new pixel structures have been designed with bias rails and bias resistors relocated. Several test beams have been carried out to evaluate the drops in the detection efficiency of the new sensor structures after irradiation. Newly developed sensor modules were irradiated with proton-beams at the Cyclotron and Radio-Isotope Center (CYRIC) in Tohoku University to see the effect of sensor-bulk damage and surface charge-up. An irradiation with γ-rays was also carried out at Takasaki Advanced Radiation Research Center, with the goal of decoupling the effect of surface charge-up from that of bulk damage. Those irradiated sensors have been evaluated with particle beams at DESY and CERN. Comparison between different sensor structures confirmed significant improvements in minimizing efficiency loss under the bias structures after irradiation. The results from γ-irradiation also enabled cross-checking the results of a semiconductor technology simulation program (TCAD). - Highlights: • The

A broadband metamaterial absorber based on multi-layer graphene in the terahertz region

Science.gov (United States)

Fu, Pan; Liu, Fei; Ren, Guang Jun; Su, Fei; Li, Dong; Yao, Jian Quan

2018-06-01

A broadband metamaterial absorber, composed of the periodic graphene pattern on SiO2 dielectric with the double layer graphene films inserted in it and all of them backed by metal plan, is proposed and investigated. The simulation results reveal that the wide absorption band can be flexibly tuned between the low-frequency band and the high-frequency band by adjusting graphene's Fermi level. The absorption can achieve 90% in 5.50-7.10 THz, with Fermi level of graphene is 0.3 eV, while in 6.98-9.10 THz with Fermi level 0.6 eV. Furthermore, the proposed structure can be switched from reflection (>81%) to absorption (>90%) over the whole operation band, when the Fermi level of graphene varies from 0 to 0.6 eV. Besides, the proposed absorber is insensitive to the polarization and can work over a wide range of incident angle. Compared with the previous broadband absorber, our graphene based wideband terahertz absorber can enable a wide application of high performance terahertz devices, including sensors, imaging devices and electro-optic switches.

Modeling of the Signal Formation in SiC Sensors for Measurements of the Radiation Spectrum in Nuclear Energy

International Nuclear Information System (INIS)

Krolikowski, Igor P.

2013-06-01

The modeling methodology of the signal formation in SiC sensors is presented. The modeling uses two approaches: the first one is the integrated approach whereas the second is the analytical approach. The sensor response is obtained from both approaches: this is the usual solution of the forward problem. Moreover, the response function of the sensor is evaluated by means of the analytical approach and it can be used to solve the inverse problem: recovering the primary radiation spectrum using the response of the sensor. Additionally, the response function returns information about the signal formation in the sensor such as the shape of the response formed by particles with a specific energy. Results obtained by simulations are then compared with experimental data. (authors)

An Assessment of Emerging Wireless Broadband Technologies

National Research Council Canada - National Science Library

Fountanas, Leonidas

2001-01-01

... technologies in providing broadband services today, emerging wireless broadband technologies are expected to significantly increase their market share over the next years, Deploying a wireless network...

Broadband Wireline Provider Service Summary; BBRI_wirelineSum12

Data.gov (United States)

University of Rhode Island Geospatial Extension Program — This dataset represents the availability of broadband Internet access in Rhode Island via all wireline technologies assessed by Broadband Rhode Island. Broadband...

Theoretical realization of robust broadband transparency in ultrathin seamless nanostructures by dual blackbodies for near infrared light

Science.gov (United States)

Zhang, Lei; Hao, Jiaming; Ye, Huapeng; Yeo, Swee Ping; Qiu, Min; Zouhdi, Said; Qiu, Cheng-Wei

2013-03-01

We propose a counter-intuitive mechanism of constructing an ultrathin broadband transparent device with two perfect blackbodies. By introducing hybridization of plasmon modes, resonant modes with different symmetries coexist in this system. A broadband transmission spectrum in the near infrared regime is achieved through controlling their coupling strengths, which is governed by the thickness of high refractive index layer. Meanwhile, the transparency bandwidth is found to be tunable in a large range by varying the geometric dimension. More significantly, from the point view of applications, the proposed method of achieving broadband transparency can perfectly tolerate the misalignment and asymmetry of periodic nanoparticles on the top and bottom, which is empowered by the unique dual of coupling-in and coupling-out processes within the pair of blackbodies. Moreover, roughness has little influence on its transmission performance. According to the coupled mode theory, the distinguished transmittance performance is physically interpreted by the radiative decay rate of the entire system. In addition to the feature of uniquely robust broadband transparency, such a ultrathin seamless nanostructure (in the presence of a uniform silver layer) also provides polarization-independent and angle-independent operations. Therefore, it may power up a wide spectrum of exciting applications in thin film protection, touch screen techniques, absorber-emitter transformation, etc.We propose a counter-intuitive mechanism of constructing an ultrathin broadband transparent device with two perfect blackbodies. By introducing hybridization of plasmon modes, resonant modes with different symmetries coexist in this system. A broadband transmission spectrum in the near infrared regime is achieved through controlling their coupling strengths, which is governed by the thickness of high refractive index layer. Meanwhile, the transparency bandwidth is found to be tunable in a large range by

A broadband two axis flux-gate magnetometer

Directory of Open Access Journals (Sweden)

P. Palangio

1998-06-01

Full Text Available A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

Analisis Perkembangan Internet Broadband di Daerah Perbatasan Sulawesi Utara

Directory of Open Access Journals (Sweden)

Riva'atul Adaniah Wahab

2016-12-01

Full Text Available Adopsi teknologi internet broadband dapat memberikan dampak ekonomi bagi masyarakat perbatasan. Karenanya pemerataan pembangunan internet broadband di wilayah  ini harus segera diwujudkan. Penelitian deskriptif kuantitatif ini dilaksanakan di wilayah perbatasan Provinsi Sulawesi Utara untuk mengetahui kondisi aspek supply dan demand perkembangan internet broadband di wilayah tersebut. Berdasarkan hasil penelitian, dapat disimpulkan bahwa dari aspek supply, kondisi infrastruktur masih sangat kurang, ketersediaan layanan internet broadband berkualitas tinggi dengan tarif rendah juga masih sulit diwujudkan. Dari aspek demand, stigma atau persepsi masyarakat bahwa internet tidak penting menjadi salah satu faktor penyebab tidak memiliki akses internet. Adapun hambatan yang paling dominan adalah ketidakpahaman dalam penggunaan internet. Faktor ini juga menjadi mendasari literasi internet broadband masyarakat pada level 0 yaitu  tidak peduli akan pentinya internet. Menanggapai kondisi ini, penyusunan dan penetapan kebijakan serta regulasi seperti QoS layanan, tarif interkoneksi, infrastructure sharing dibuat untuk menyediakan internet broadband berkualitas tinggi dengan harga murah. Selain itu distribusi perangkat mobile berharga murah (smartphone juga perlu didorong dengan penerapan TKDN untuk produksi perangkat. Tidak kalah pentingnya adalah peningkatan literasi internet broadband masyarakat melalui sosialisasi atau pelatihan baik formal maupun nonformal. Abstract   Adoption of internet broadband internet can provide the economic impact for border communities. Hence equitable development of internet broadband in the region should be immediately implemented. This quantitative descriptive study was conducted in the border region of North Sulawesi to determine the condition of supply and demand aspects of the development of internet broadband. Based on the results, it can be concluded that from the aspect of supply, the condition of the

Determining of the electric field strength using high frequency broadband measurements

Directory of Open Access Journals (Sweden)

Vulević Branislav D.

2017-01-01

Full Text Available Exposure of humans to electromagnetic fields of high frequency (above 100 kHz, i.e. radiofrequency radiation from the modern wireless systems, today inevitable is. The purpose of this paper is to highlight the importance of broadband measurements of the electric field of high frequency in order to fast and reliable assessment of human exposure. A practical method of ‘in situ’ measurement the electric field intensity which is related to the frequency range of 3 MHz to 18 GHz, is provided.

Proton Radiation Effects on Dark Signal Distribution of PPD CMOS Image Sensors: Both TID and DDD Effects.

Science.gov (United States)

Xue, Yuanyuan; Wang, Zujun; Chen, Wei; Liu, Minbo; He, Baoping; Yao, Zhibin; Sheng, Jiangkun; Ma, Wuying; Dong, Guantao; Jin, Junshan

2017-11-30

Four-transistor (T) pinned photodiode (PPD) CMOS image sensors (CISs) with four-megapixel resolution using 11µm pitch high dynamic range pixel were radiated with 3 MeV and 10MeV protons. The dark signal was measured pre- and post-radiation, with the dark signal post irradiation showing a remarkable increase. A theoretical method of dark signal distribution pre- and post-radiation is used to analyze the degradation mechanisms of the dark signal distribution. The theoretical results are in good agreement with experimental results. This research would provide a good understanding of the proton radiation effects on the CIS and make it possible to predict the dark signal distribution of the CIS under the complex proton radiation environments.

An Improved Measurement Method for the Strength of Radiation of Reflective Beam in an Industrial Optical Sensor Based on Laser Displacement Meter

Directory of Open Access Journals (Sweden)

Youngchul Bae

2016-05-01

Full Text Available An optical sensor such as a laser range finder (LRF or laser displacement meter (LDM uses reflected and returned laser beam from a target. The optical sensor has been mainly used to measure the distance between a launch position and the target. However, optical sensor based LRF and LDM have numerous and various errors such as statistical errors, drift errors, cyclic errors, alignment errors and slope errors. Among these errors, an alignment error that contains measurement error for the strength of radiation of returned laser beam from the target is the most serious error in industrial optical sensors. It is caused by the dependence of the measurement offset upon the strength of radiation of returned beam incident upon the focusing lens from the target. In this paper, in order to solve these problems, we propose a novel method for the measurement of the output of direct current (DC voltage that is proportional to the strength of radiation of returned laser beam in the received avalanche photo diode (APD circuit. We implemented a measuring circuit that is able to provide an exact measurement of reflected laser beam. By using the proposed method, we can measure the intensity or strength of radiation of laser beam in real time and with a high degree of precision.

Piezoelectric energy harvesting from broadband random vibrations

International Nuclear Information System (INIS)

Adhikari, S; Friswell, M I; Inman, D J

2009-01-01

Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. Most works using deterministic approaches focusing on using the piezoelectric effect to harvest ambient vibration energy have concentrated on cantilever beams at resonance using harmonic excitation. Here, using a stochastic approach, we focus on using a stack configuration and harvesting broadband vibration energy, a more practically available ambient source. It is assumed that the ambient base excitation is stationary Gaussian white noise, which has a constant power-spectral density across the frequency range considered. The mean power acquired from a piezoelectric vibration-based energy harvester subjected to random base excitation is derived using the theory of random vibrations. Two cases, namely the harvesting circuit with and without an inductor, have been considered. Exact closed-form expressions involving non-dimensional parameters of the electromechanical system have been given and illustrated using numerical examples

Piezoelectric energy harvesting from broadband random vibrations

Science.gov (United States)

Adhikari, S.; Friswell, M. I.; Inman, D. J.

2009-11-01

Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. Most works using deterministic approaches focusing on using the piezoelectric effect to harvest ambient vibration energy have concentrated on cantilever beams at resonance using harmonic excitation. Here, using a stochastic approach, we focus on using a stack configuration and harvesting broadband vibration energy, a more practically available ambient source. It is assumed that the ambient base excitation is stationary Gaussian white noise, which has a constant power-spectral density across the frequency range considered. The mean power acquired from a piezoelectric vibration-based energy harvester subjected to random base excitation is derived using the theory of random vibrations. Two cases, namely the harvesting circuit with and without an inductor, have been considered. Exact closed-form expressions involving non-dimensional parameters of the electromechanical system have been given and illustrated using numerical examples.

Chaos-assisted broadband momentum transformation in optical microresonators.

Science.gov (United States)

Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

2017-10-20

The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Broadband availability in metropolitan and non-metropolitan Pennsylvania

Directory of Open Access Journals (Sweden)

Lawrence E. Wood

2016-09-01

Full Text Available Over the past few years having a broadband connection has become essential for many Internet activities. As broadband increases in importance, it becomes imperative to assess how its use and availability may vary, especially in relation to issues such as geographic location. For rural areas in particular, the availability of broadband service is especially important. This research assesses broadband service availability in rural areas of Pennsylvania, USA. In particular, it examines the extent to which Digital Subscriber Line (DSL and broadband cable modem services are being deployed throughout rural Pennsylvania. It compares this deployment with the availability of such services in the state’s urban and metropolitan areas. The results of this research suggest that there is a “digital divide” in terms of broadband availability between rural and urban areas of Pennsylvania. However, this “divide” is perhaps not as wide as might be expected. Thus, as broadband is becoming increasingly available in rural areas of the U.S. and throughout much of the rest of the world, this research concludes that while research must remain vigilant in terms of assessing advanced telecommunications availability in rural areas, future research should also be sure to focus on how such technologies can be used to promote economic and social concerns, including in relation to building online networks and diminishing social and professional isolation in rural areas.

Analyzing Broadband Divide in the Farming Sector

DEFF Research Database (Denmark)

Jensen, Michael; Gutierrez Lopez, Jose Manuel; Pedersen, Jens Myrup

2013-01-01

, upstream and downstream connection. The main constraint is that farms are naturally located in rural areas where the required access broadband data rates are not available. This paper studies the broadband divide in relation to the Danish agricultural sector. Results show how there is an important......Agriculture industry has been evolving for centuries. Currently, the technological development of Internet oriented farming tools allows to increase the productivity and efficiency of this sector. Many of the already available tools and applications require high bandwidth in both directions...... difference between the broadband availability for farms and the rest of the households/buildings the country. This divide may be slowing down the potential technological development of the farming industry, in order to keep their competitiveness in the market. Therefore, broadband development in rural areas...

Fiber-linked interferometric pressure sensor

Science.gov (United States)

Beheim, G.; Fritsch, K.; Poorman, R. N.

1987-01-01

A fiber-optic pressure sensor is described which uses a diaphragm to modulate the mirror separation of a Fabry-Perot cavity (the sensing cavity). A multimode optical fiber delivers broadband light to the sensing cavity and returns the spectrally modulated light which the cavity reflects. The sensor's output spectrum is analyzed using a tunable Fabry-Perot cavity (the reference cavity) to determine the mismatch in the mirror separations of the two cavities. An electronic servo control uses this result to cause the mirror separation of the reference cavity to equal that of the sensing cavity. The displacement of the pressure-sensing diaphragm is then obtained by measuring the capacitance of the reference cavity's metal-coated mirrors. Relative to other fiber-optic sensors, an important advantage of this instrument is its high immunity to the effects of variations in both the transmissivity of the fiber link and the wavelength of the optical source.

Femtosecond Broadband Stimulated Raman Spectroscopy

International Nuclear Information System (INIS)

Lee, Soo-Y; Yoon, Sagwoon; Mathies, Richard A

2006-01-01

Femtosecond broadband stimulated Raman spectroscopy (FSRS) is a new technique where a narrow bandwidth picosecond Raman pump pulse and a red-shifted broadband femtosecond Stokes probe pulse (with or without time delay between the pulses) act on a sample to produce a high resolution Raman gain spectrum with high efficiency and speed, free from fluorescence background interference. It can reveal vibrational structural information and dynamics of stationary or transient states. Here, the quantum picture for femtosecond broadband stimulated Raman spectroscopy (FSRS) is used to develop the semiclassical coupled wave theory of the phenomenon and to derive an expression for the measurable Raman gain in FSRS. The semiclassical theory is applied to study the dependence of lineshapes in FSRS on the pump-probe time delay and to deduce vibrational dephasing times in cyclohexane in the ground state

Silicon sensors for trackers at high-luminosity environment

Energy Technology Data Exchange (ETDEWEB)

Peltola, Timo, E-mail: timo.peltola@helsinki.fi

2015-10-01

The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system that was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than in the current LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 Collaboration “Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders” to develop silicon sensors with sufficient radiation tolerance. Research topics include the improvement of the intrinsic radiation tolerance of the sensor material and novel detector designs with benefits like reduced trapping probability (thinned and 3D sensors), maximized sensitive area (active edge sensors) and enhanced charge carrier generation (sensors with intrinsic gain). A review of the recent results from both measurements and TCAD simulations of several detector technologies and silicon materials at radiation levels expected for HL-LHC will be presented. - Highlights: • An overview of the recent results from the RD50 collaboration. • Accuracy of TCAD simulations increased by including both bulk and surface damage. • Sensors with n-electrode readout and MCz material offer higher radiation hardness. • 3D detectors are a promising choice for the extremely high fluence environments. • Detectors with an enhanced charge carrier generation under systematic investigation.

Observation of Broadband Time-Dependent Rabi Shifting in Microplasmas

International Nuclear Information System (INIS)

Compton, Ryan; Filin, Alex; Romanov, Dmitri A.; Levis, Robert J.

2009-01-01

Coherent broadband radiation in the form of Rabi sidebands is observed when a ps probe laser propagates through a weakly ionized, electronically excited microplasma generated in the focus of an intense pump beam. The sidebands arise from the interaction of the probe beam with pairs of excited states of a constituent neutral atom via the probe-induced Rabi oscillation. Sideband shifting of >90 meV from the probe carrier frequency results in an effective bandwidth of 200 meV. The sidebands are controlled by the intensity and temporal profile of the probe pulse; with amplitude and shift in agreement with the predictions of a time-dependent generalized Rabi cycling model.

High quality broadband spatial reflections of slow Rayleigh surface acoustic waves modulated by a graded grooved surface

KAUST Repository

Xu, Yanlong

2015-01-21

We report high quality broadband spatial reflections of Rayleigh surface acoustic waves (SAWs) through a graded grooved surface. High quality means that no wave is allowed to transmit and the incident wave is nearly all reflected to the input side. The graded grooved surface is structured by drilling one dimensional array of graded grooves with increased depths on a flat surface. We investigate SAW dispersion relations, wave field distribution at several typical SAW wavelengths, and time evolution of a Gaussian pulse through the graded grooved surface. Results show that the input broadband Rayleigh SAWs can be slowed, spatially enhanced and stopped, and finally reflected to the input side. The study suggests that engraving the flat surface can be used as an efficient and economical way to manipulate Rayleigh SAWs, which has potential application in novel SAW devices such as filters, reflectors, sensors, energy harvesters, and diodes.

Evaluation of the new infrastructure for French Permanent Broadband Stations in Auvergne (France).

Science.gov (United States)

Douchain, J. M.; Regis, E.; Battaglia, J.; Vergne, J.

2017-12-01

French seismologic and geodetic network (RESIF) is a national equipment for the observation and understanding of the solid Earth. It is an instrument aimed at acquiring new top-quality data for disciplines like seismology, geodesy and gravimetry to advance the understanding of the dynamics of our planet. The seismology component of RESIF, with its homogeneous coverage of the territory, will allow better localisation and characterisation of seismic activityover a wide range of magnitudes as well as provide high quality data for research The Auvergne Seismic Network (ASN) manages seismic stations in the center of france since the beginning of the 80's and continuously ugrades them. Nowadays, 21 stations (velocimeters and accelerometers) are deployed to monitor the Massif Central seismic activity. In the future, the ASN will run 15 broadband stations that will be part of RESIF network. Six of theses sites already have former generation instrumentation (short period sensors buried in the ground, low dynamic) but others are completely new. In june 2017, 4 permanent seismic stations have been upgraded to the new standard installation type for open environment. The chozen infrastructure is a 5 meter drilling equiped with a posthole broadband sensor. Prior to these final installations, on each site, Trillium 120 PA have been installed for 2 temporary experiments. The first one consisted of a direct burial installations at about 80 centimeters depth and lasted for 1 or 2 months. The second dataset was recorded in shallow seismic vaults, during 6 months.In this study, we compare, for each site, data recorded with the 3 configurations in order to evaluate the profits of the new RESIF installations. For this purpose, we compare the probability density fonctions to evaluate noise levels, as well as sprectrograms and hourly detection number. Our results show that the installation of sensors in drillings greatly improves the quality of data at low and high frequencies.

Practical Use Technique of Sensor

International Nuclear Information System (INIS)

Hwang, Gyu Seop

1985-11-01

This book tells of practical use technology of sensor, introducing the recent trend of sensor for electronic industry, IC temperature sensor, radiation temperature sensor of surface acoustic wave, optical fiber temperature sensor, a polyelectrolyte film humidity sensor, semiconductor pressure sensor for industrial instrumentation, silicon integration pressure sensor, thick film humidity sensor and its application, photo sensor reflection type, and color sensor. It also deals with sensor for FA, sensor for a robot and sensor for the chemical industry.

Practical Use Technique of Sensor

Energy Technology Data Exchange (ETDEWEB)

Hwang, Gyu Seop

1985-11-15

This book tells of practical use technology of sensor, introducing the recent trend of sensor for electronic industry, IC temperature sensor, radiation temperature sensor of surface acoustic wave, optical fiber temperature sensor, a polyelectrolyte film humidity sensor, semiconductor pressure sensor for industrial instrumentation, silicon integration pressure sensor, thick film humidity sensor and its application, photo sensor reflection type, and color sensor. It also deals with sensor for FA, sensor for a robot and sensor for the chemical industry.

Cosmic non-TEM radiation and synthetic feed array sensor system in ASIC mixed signal technology

Science.gov (United States)

Centureli, F.; Scotti, G.; Tommasino, P.; Trifiletti, A.; Romano, F.; Cimmino, R.; Saitto, A.

2014-08-01

The paper deals with the opportunity to introduce "Not strictly TEM waves" Synthetic detection Method (NTSM), consisting in a Three Axis Digital Beam Processing (3ADBP), to enhance the performances of radio telescope and sensor systems. Current Radio Telescopes generally use the classic 3D "TEM waves" approximation Detection Method, which consists in a linear tomography process (Single or Dual axis beam forming processing) neglecting the small z component. The Synthetic FEED ARRAY three axis Sensor SYSTEM is an innovative technique using a synthetic detection of the generic "NOT strictly TEM Waves radiation coming from the Cosmo, which processes longitudinal component of Angular Momentum too. Than the simultaneous extraction from radiation of both the linear and quadratic information component, may reduce the complexity to reconstruct the Early Universe in the different requested scales. This next order approximation detection of the observed cosmologic processes, may improve the efficacy of the statistical numerical model used to elaborate the same information acquired. The present work focuses on detection of such waves at carrier frequencies in the bands ranging from LF to MMW. The work shows in further detail the new generation of on line programmable and reconfigurable Mixed Signal ASIC technology that made possible the innovative Synthetic Sensor. Furthermore the paper shows the ability of such technique to increase the Radio Telescope Array Antenna performances.

A scaling law derived from a broadband impedance applications to SPEAR

International Nuclear Information System (INIS)

Vos, L.

1990-01-01

The bunch length in high-brightness synchrotron radiation sources is an important performance parameter. It is critically dependent on the μ-wave instability. Usually the SPEAR scaling law is used to compute the expected bunch length. In this paper we show that the SPEAR scaling law is compatible with a broadband impedance. This makes it possible to calculate the appropriate scaling law for a machine like the one proposed in Berkeley assuming that the impedance is known from measurements and/or calculations. (author) 4 refs., 5 figs., 1 tab

Testing of Sapphire Optical Fiber and Sensors in Intense Radiation Fields When Subjected to Very High Temperatures

Energy Technology Data Exchange (ETDEWEB)

Blue, Thomas [The Ohio State Univ., Columbus, OH (United States); Windl, Wolfgang [The Ohio State Univ., Columbus, OH (United States)

2017-12-15

The primary objective of this project was to determine the optical attenuation and signal degradation of sapphire optical fibers & sensors (temperature & strain), in-situ, operating at temperatures up to 1500°C during reactor irradiation through experiments and modeling. The results will determine the feasibility of extending sapphire optical fiber-based instrumentation to extremely high temperature radiation environments. This research will pave the way for future testing of sapphire optical fibers and fiber-based sensors under conditions expected in advanced high temperature reactors.

Radiation-resistant optical sensors and cameras; Strahlungsresistente optische Sensoren und Kameras

Energy Technology Data Exchange (ETDEWEB)

Fischer, G. [Imaging and Sensing Technology, Bonn (Germany)

2008-02-15

Introducing video technology, i.e. 'TV', specifically in the nuclear field was considered at an early stage. Possibilities to view spaces in nuclear facilities by means of radiation-resistant optical sensors or cameras are presented. These systems are to enable operators to monitor and control visually the processes occurring within such spaces. Camera systems are used, e.g., for remote surveillance of critical components in nuclear power plants and nuclear facilities, and thus contribute also to plant safety. A different application of optical systems resistant to radiation is in the visual inspection of, e.g., reactor pressure vessels and in tracing small parts inside a reactor. Camera systems are also employed in remote disassembly of radioactively contaminated old plants. Unfortunately, the niche market of radiation-resistant camera systems hardly gives rise to the expectation of research funds becoming available for the development of new radiation-resistant optical systems for picture taking and viewing. Current efforts are devoted mainly to improvements of image evaluation and image quality. Other items on the agendas of manufacturers are the reduction in camera size, which is limited by the size of picture tubes, and the increased use of commercial CCD cameras together with adequate shieldings or improved lenses. Consideration is also being given to the use of periphery equipment and to data transmission by LAN, WAN, or Internet links to remote locations. (orig.)

Management of broadband technology and innovation policy, deployment, and use

CERN Document Server

Choudrie, Jyoti

2013-01-01

When one considers broadband, the Internet immediately springs to mind. However, broadband is impacting society in many ways. For instance, broadband networks can be used to deliver healthcare or community related services to individuals who don't have computers, have distance as an issue to contend with, or don't use the internet. Broadband can support better management of scarce energy resources with the advent of smart grids, enables improved teleworking capacity and opens up a world of new entertainment possibilities. Yet scholarly examinations of broadband technology have so far examin

75 FR 10464 - Broadband Technology Opportunities Program

Science.gov (United States)

2010-03-08

... window for Public Computer Center (PCC) and Sustainable Broadband Adoption (SBA) projects. DATES: All...; Extension of Application Closing Deadline for Comprehensive Community Infrastructure (CCI) Projects. SUMMARY... Infrastructure (CCI) projects under the Broadband Technology Opportunities Program (BTOP) is extended until 5:00...

Broadband for all closing the infrastructure gap

CSIR Research Space (South Africa)

Roux, K

2015-10-01

Full Text Available than just addressing the infrastructure issue. The CSIR is mapping the country’s broadband infrastructure to understand where the largest gaps are, is developing models for how those gaps in broadband infrastructure can be closed. In this presentation...

Local government broadband policies for areas with limited Internet access

Directory of Open Access Journals (Sweden)

Yoshio Arai

2014-03-01

Full Text Available Despite their wide diffusion in developed countries, broadband services are still limited in areas where providing them is not profitable for private telecom carriers. To address this, many local governments in Japan have implemented broadband deployment projects subsidized by the national government. In this paper, we discuss local government broadband policies based on survey data collected from municipalities throughout the country. With the support of national promotion policies, broadband services were rapidly introduced to most local municipalities in Japan during the 2000s. Local government deployment policies helped to reduce the number of areas with no broadband access. A business model based on the Indefeasible Right of Use (IRU contract between a private telecom carrier and a local government has been developed in recent years. Even local governments without the technical capacity to operate a broadband business can introduce broadband services into their territory using the IRU business model.

Anomalous Temporal Behaviour of Broadband Ly Alpha Observations During Solar Flares from SDO/EVE

Science.gov (United States)

Milligan, Ryan O.; Chamberlin, Phillip C.

2016-01-01

Although it is the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyman-alpha (Ly-alpha) emission during solar flares in recent years. However, the few examples that do exist have shown Ly-alpha emission to be a substantial radiator of the total energy budget of solar flares (of the order of 10 percent). It is also a known driver of fluctuations in the Earth's ionosphere. The EUV (Extreme Ultra-Violet) Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) now provides broadband, photometric Ly-alpha data at 10-second cadence with its Multiple EUV Grating Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar flares in the 5 years since it was launched. However, the MEGS-P time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H-alpha, Ly-beta, LyC, C III, etc.). Furthermore, the emission detected by MEGS-P peaks around the time of the peak of thermal soft X-ray emission and not during the impulsive phase when energy deposition in the chromosphere (often assumed to be in the form of non-thermal electrons) is greatest. The time derivative of Ly-alpha lightcurves also appears to resemble that of the time derivative of soft X-rays, reminiscent of the Neupert effect. Given that spectrally-resolved Ly-alpha observations during flares from SORCE / SOLSTICE (Solar Radiation and Climate Experiment / Solar Stellar Irradiance Comparison Experiment) peak during the impulsive phase as expected, this suggests that the atypical behaviour of MEGS-P data is a manifestation of the broadband nature of the observations. This could imply that other lines andor continuum emission that becomes enhanced during flares could be contributing to the passband. Users are hereby urged to exercise caution when interpreting

Optical Cherenkov radiation in an As2S3 slot waveguide with four zero-dispersion wavelengths

DEFF Research Database (Denmark)

Wang, Shaofei; Hu, Jungao; Guo, Hairun

2013-01-01

, dispersion profiles with four zero dispersion wavelengths are found to produce a phase-matching nonlinear process leading to a broadband resonant radiation. The broadband OCR investigated in the chalcogenide waveguide may find applications in on-chip wavelength conversion and near-infrared pulse generation.......We propose an approach for an efficient generation of optical Cherenkov radiation (OCR) in the near-infrared by tailoring the waveguide dispersion for a zero group-velocity mismatching between the radiation and the pump soliton. Based on an As2S3 slot waveguide with subwavelength dimensions...

Service Differentiation in Residential Broadband Networks

DEFF Research Database (Denmark)

Sigurdsson, Halldór Matthias

2004-01-01

As broadband gains widespread adoption with residential users, revenue generating voice- and video-services have not yet taken off. This slow uptake is often attributed to lack of Quality of Service management in residential broadband networks. To resolve this and induce service variety, network...... access providers are implementing service differentiation in their networks where voice and video gets prioritised before data. This paper discusses the role of network access providers in multipurpose packet based networks and the available migration strategies for supporting multimedia services...... in digital subscriber line (DSL) based residential broadband networks. Four possible implementation scenarios and their technical characteristics and effects are described. To conclude, the paper discusses how network access providers can be induced to open their networks for third party service providers....

Autonomous BBOBS-NX (NX-2G) for New Era of Ocean Bottom Broadband Seismology

Science.gov (United States)

Shiobara, H.; Ito, A.; Sugioka, H.; Shinohara, M.

2017-12-01

The broadband ocean bottom seismometer (BBOBS) and its new generation system (BBOBS-NX) have been developed in Japan, and we performed several test and practical observations to create and establish a new category of the ocean floor broadband seismology, since 1999. Now, the data obtained by our BBOBS and BBOBS-NX is proved to be adequate for broadband seismic analyses. Especially, the BBOBS-NX can obtain the horizontal data comparable to land sites in longer periods (10 s -). Moreover, the BBOBST-NX is in practical evaluation for the mobile tilt observation that enables dense geodetic monitoring. The BBOBS-NX system is a powerful tool, although, it has intrinsic limitation of the ROV operation. If this system can be used without the ROV, like as the BBOBS, it should lead us a true breakthrough of ocean bottom seismology. Hereafter, the new autonomous BBOBS-NX is noted as NX-2G in short. The main problem to realize the NX-2G is a tilt of the sensor unit on landing, which exceed the acceptable limit (±8°) in about 50%. As we had no evidence at which moment and how this tilt occurred, we tried to observe it during the BBOBST-NX landing in 2015 by attaching a video camera and an acceleration logger. The result shows that the tilt on landing was determined by the final posture of the system at the penetration into the sediment, and the large oscillating tilt more than ±10° was observed in descending. The function of the NX-2G system is based on 3 stage operations as shown in the image. The glass float is aimed not only to obtain enough buoyancy to extract the sensor unit, but also to suppress the oscillating tilt of the system in descending. In Oct. 2016, we made the first in-situ test of the NX-2G system with a ROV. It was dropped from the sea surface with the video camera and the acceleration logger. The ROV was used to watch the operation of the system at the seafloor. The landing looked well and it was examined from the acceleration data. As the maximum tilt in

Radiation hardening of optical fibers and fiber sensors for space applications: recent advances

Science.gov (United States)

Girard, S.; Ouerdane, Y.; Pinsard, E.; Laurent, A.; Ladaci, A.; Robin, T.; Cadier, B.; Mescia, L.; Boukenter, A.

2017-11-01

In these ICSO proceedings, we review recent advances from our group concerning the radiation hardening of optical fiber and fiber-based sensors for space applications and compare their benefits to state-of-the-art results. We focus on the various approaches we developed to enhance the radiation tolerance of two classes of optical fibers doped with rare-earths: the erbium (Er)-doped ones and the ytterbium/erbium (Er/Yb)-doped ones. As a first approach, we work at the component level, optimizing the fiber structure and composition to reduce their intrinsically high radiation sensitivities. For the Erbium-doped fibers, this has been achieved using a new structure for the fiber that is called Hole-Assisted Carbon Coated (HACC) optical fibers whereas for the Er/Ybdoped optical fibers, their hardening was successfully achieved adding to the fiber, the Cerium element, that prevents the formation of the radiation-induced point defects responsible for the radiation induced attenuation in the infrared part of the spectrum. These fibers are used as part of more complex systems like amplifiers (Erbium-doped Fiber Amplifier, EDFA or Yb-EDFA) or source (Erbium-doped Fiber Source, EDFS or Yb- EDFS), we discuss the impact of using radiation-hardened fibers on the system radiation vulnerability and demonstrate the resistance of these systems to radiation constraints associated with today and future space missions. Finally, we will discuss another radiation hardening approach build in our group and based on a hardening-by-system strategy in which the amplifier is optimized during its elaboration for its future mission considering the radiation effects and not in-lab.

Development of beam halo monitors for the European XFEL using radiation hard sensors and demonstration of the technology at FLASH

International Nuclear Information System (INIS)

Ignatenko, Alexandr

2015-05-01

The European X-Ray Free-Electron Laser (E-XFEL), currently under construction in Hamburg, Germany, is intended to be an international linear accelerator (linac) based user facility. Its electron beam can carry maximal average power of 600 kW. A beam with such a high power needs to be carefully transmitted through the machine and safely dumped after utilization. This is supported by various diagnostics tools. A Beam Halo Monitor (BHM) based on synthetic diamond and sapphire sensors has been designed. Diamond sensors are developed by the company element6 for the detection of ionizing radiation and used previously elsewhere. Sapphire sensors are in this thesis applied for the first time. The BHM concept has been applied already at the Free-electron Laser in Hamburg (FLASH). A module with four diamond and four sapphire sensors was designed, installed inside the beam pipe, commissioned, calibrated and has been successfully operated for 4 years. The system contributed significantly to safe and efficient operation of FLASH. Both types of the sensors for the BHM were characterized. Measurements of radiation tolerance are done in a 10 MeV electron beam for polycrystalline CVD (pCVD) diamond sensors for the first time up to a dose of 10 MGy and for sapphire sensors up to 5 MGy. The charge collection efficiency (CCE) drops as a function of the absorbed dose, is however still sufficient for application as a BHM. To improve a main sensor characteristic, the charge collection efficiency, for sapphire sensors the impurity concentration was reduced and different growth techniques were compared. Finally, charge collection efficiency of about 5 % for a bias voltage of 500 V was reached. The BHM concept for the XFEL is designed and in the construction phase.

Methodology and measurement of radiation interception by quantum sensor of the oil palm plantation

Directory of Open Access Journals (Sweden)

Johari Endan

2005-09-01

Full Text Available Interception of light by a canopy is a fundamental requirement for crop growth and is important for biomass production and plant growth modeling. Solar radiation is an important parameter for photosynthesis and evapotranspiration. These two phenomena are dependent not only on the intensity of radiation but also on the distribution of intercepted radiation within the canopy. In this study, two operational methods for estimating the amount of photosynthetically active radiation (PAR intercepted by a canopy of the oil palm are presented. LICOR radiation sensors, model LI-190SA and model LI-191SA were used for photosynthetically active radiation (PAR measurement above and below the canopy. We developed two methods, namely "Triangular" method and "Circular" method for PAR measurement. Results show that both methods were suitable for oil palm PAR measurement. The triangular method is recommended for PAR measurements with respect to the whole plantation and the circular method is recommended for specific purposes, such as growth analysis or growth modeling of the oil palm. However, practical considerations such as equipment availability, purpose of the measurement, age of the palm, and the number of measuring points to be sampled should be taken into account in the selection of a suitable method for a particular study. The results indicate that the interception of radiation was affected by spatial variation, and the radiation transmission decreased towards the frond tips.

Broadband Electromagnetic Technology

Science.gov (United States)

2011-06-23

The objectives of this project are to continue the enhancements to the combined Broadband Electromagnetic and Full Encirclement Unit (BEM-FEU) technologies and to evaluate the systems capability in the laboratory and the field. The BEM instrument ...

The relationship investigation between factors affecting demand for broadband and the level of satisfaction among broadband customers in the South East Coast of Sabah, Malaysia

Science.gov (United States)

Hashim, S. H. A.; Hamid, F. A.; Kiram, J. J.; Sulaiman, J.

2017-09-01

This paper aims to investigate the relationship between factors that affecting the demand for broadband and the level of satisfaction. Previous researchers have found that the adoption of broadband is greatly influenced by many factors. Thus, in this study, a self-administered questionnaire was developed to obtain the factors affecting demand for broadband among broadband customers as well as their level of satisfaction. Pearson correlation, one-way analysis of variance (ANOVA) and t-test were used for statistical interpretation of the relationship. This study shows that there are better relationships between several factors over demand for broadband and satisfaction level.

Assessing the utility of the spot 6 sensor in detecting and mapping ...

African Journals Online (AJOL)

Lantana camara is a significant weed in South Africa which is causing severe impacts on agriculture by reducing grazing areas. This study assessed the potential of the SPOT 6 multispectral sensor and two broadband vegetation indices (NDVI and SR) for detecting and mapping Lantana camara in a community grazing ...

Manta A New BroadBand OBS

Science.gov (United States)

Hello, Y.; Yegikyan, M.; Charvis, P.; Philippe, O.

2017-12-01

Manta is a new BroadBand OBS developed at Geoazur and commercialized by Osean. The design is inspired by 3-years autonomy MUG-OBS a Multiparameter Ocean Bottom System which carry a lot of sort of sensor types. As Mug-OBS, Manta-OBS rated 6000m is designed to resist a trawling. All the components are non corrosive such polyethylene, titanium and buoyancy is ensured by syntactic foam. Equipped in standard version with a Trillium compact OBS Manta has an autonomy of 18 months, but can accept on its 4 input channels any kind of signal as low as from an hydrophone or larger from other type of a seismometer or accelerometer. Tri-axial geophones unit (2 Hz or 4.5 Hz ) can replace the seismometer and will expend the lifespan for the instrument. The seismometer is encapsulated in a central well established by four panels of the main structure to protect it from sea current convection and is decoupled from main chassis. An health bulletin is recoverable by acoustic any time to facilitate the installation and during a visit when instrument is deployed. Main parameters for acquisition can be changed by acoustics command from surface at any time. Once at the bottom, release for the main sensor installation is programmed on a timer but controlled by the tilt of the OBS. If the tilt is too important based on programmed limits, sensor will not released automatically, but this can be forced by acoustic command after returning the tilt informations to the boat operator. Manta is equipped with flash light and AIS system for easy location at recovery, and can also send it's position by Iridium satellite in case of an unexpected ascent such caused by a possible trawling if deployed in shallow water. Clock drift calculation is automatically made against GPS time signal once the OBS return at the surface. The recovery of the OBS is initiated by an acoustic command. These new features made Manta a very versatile instrument for monitoring earthquakes.

Optical measuring system with an interrogator and a polymer-based single-mode fibre optic sensor system

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to an optical measuring system comprising a polymer-based single-mode fibre-optic sensor system (102), an optical interrogator (101), and an optical arrangement (103) interconnecting the optical interrogator (101) and the polymer-based single-mode fibre-optic sensor...... system (102). The invention further relates to an optical interrogator adapted to be connected to a polymer-based single-mode fibre-optic sensor system via an optical arrangement. The interrogator comprises a broadband light source arrangement (104) and a spectrum analysing arrangement which receives...

VT Public Locations of Broadband Data - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Public Locations of Broadband Data - 12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT Public Locations of Broadband Data - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT Public Locations of Broadband Data - 12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

7 CFR 1738.11 - Availability of broadband service.

Science.gov (United States)

2010-01-01

..., DEPARTMENT OF AGRICULTURE RURAL BROADBAND ACCESS LOANS AND LOAN GUARANTEES Loan Purposes and Basic Policies... given to loans to finance service to eligible rural communities in which broadband service is not...

VT Public Locations of Broadband Data - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT Public Locations of Broadband Data - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

Broadband Liner Optimization for the Source Diagnostic Test Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.

2012-01-01

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

Radiation effects on optical components of a laser radar sensor designed for remote metrology in ITER

International Nuclear Information System (INIS)

Menon, M.M.; Grann, E.B.; Slotwinski, A.

1997-09-01

A frequency modulated laser radar is being developed for in-vessel metrology and viewing of plasma-facing surfaces. Some optical components of this sensor must withstand intense gamma radiation (3 x 10 6 rad/h) during operation. The authors have tested the effect of radiation on a silica core polarization maintaining optical fiber and on TeO 2 crystals at doses up to ∼ 10 9 rad. Additional tests are planned for evaluating the performance of a complete acousto-optic (AO) scanning device. The progress made in these tests is also described

Feasibility study of the optical fiber Bragg grating sensors in radiation environment

Energy Technology Data Exchange (ETDEWEB)

Fujita, Kaoru; Kimura, Atsushi; Nakazawa, Masaharu [Tokyo Univ., Dept. of Quantum Engineering and Systems Science, Tokyo (Japan); Takahashi, Hiroyuki [Tokyo Univ., Center of Engineering, Research into Artifacts, Tokyo (Japan); Ariyoshi, Masahiko [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan)

2002-09-01

Applicability of an optical fiber Bragg grating (FBG)-based vibration sensor to radiation environment was investigated for monitoring nuclear plants. The FBG sensor is a kind of optical fiber sensors which is developing rapidly in recent years. FBGs reflect light which fulfill the Bragg condition {lambda} = 2 n L, where {lambda} is the wave length of reflecting light, n and L are the effective refractive index and length of the modulation period in grating part, respectively. The strain on FBGs influences on n and L and causes shift of {lambda}. The sensitivity to strain of FBG were investigated. The FBGs was irradiated with gamma-rays to investigate the irradiation effects on the FBGs. The Bragg wavelength of FBGs is not affected by gamma-rays up to 1.0 MGy of total absorbed dose. In vibration measurement system, two FBGs were attached to a thin iron plate. Each FBG was set up both side of the thin plate and spliced in series. An audio speaker was used as a vibration source. FBGs were irradiated at the dose rate of 50Gy/h and the vibration were observed in situ. Input signals from oscillator, the output from FBG sensors and the power spectra of the two signals were measured. The output signal was very noisy, however, the peak of the frequency is corresponding. The noise seemed to be arisen during the vibration traveled between the speaker and the plate and considered to be not essential. As a result, it is shown that a change of frequency at the vibration source could be followed by FBG-based sensors. To reduce the noise, the method for conducting the vibration to FBGs should be improved. (M. Suetake)

Feasibility study of the optical fiber Bragg grating sensors in radiation environment

International Nuclear Information System (INIS)

Fujita, Kaoru; Kimura, Atsushi; Nakazawa, Masaharu; Takahashi, Hiroyuki; Ariyoshi, Masahiko

2002-01-01

Applicability of an optical fiber Bragg grating (FBG)-based vibration sensor to radiation environment was investigated for monitoring nuclear plants. The FBG sensor is a kind of optical fiber sensors which is developing rapidly in recent years. FBGs reflect light which fulfill the Bragg condition λ = 2 n L, where λ is the wave length of reflecting light, n and L are the effective refractive index and length of the modulation period in grating part, respectively. The strain on FBGs influences on n and L and causes shift of λ. The sensitivity to strain of FBG were investigated. The FBGs was irradiated with gamma-rays to investigate the irradiation effects on the FBGs. The Bragg wavelength of FBGs is not affected by gamma-rays up to 1.0 MGy of total absorbed dose. In vibration measurement system, two FBGs were attached to a thin iron plate. Each FBG was set up both side of the thin plate and spliced in series. An audio speaker was used as a vibration source. FBGs were irradiated at the dose rate of 50Gy/h and the vibration were observed in situ. Input signals from oscillator, the output from FBG sensors and the power spectra of the two signals were measured. The output signal was very noisy, however, the peak of the frequency is corresponding. The noise seemed to be arisen during the vibration traveled between the speaker and the plate and considered to be not essential. As a result, it is shown that a change of frequency at the vibration source could be followed by FBG-based sensors. To reduce the noise, the method for conducting the vibration to FBGs should be improved. (M. Suetake)

Broadband transmission masks, gratings and filters for extreme ultraviolet and soft X-ray lithography

International Nuclear Information System (INIS)

Brose, S.; Danylyuk, S.; Juschkin, L.; Dittberner, C.; Bergmann, K.; Moers, J.; Panaitov, G.; Trellenkamp, St.; Loosen, P.; Grützmacher, D.

2012-01-01

Lithography and patterning on a nanometre scale with extreme ultraviolet (EUV) and soft X-ray radiation allow creation of high resolution, high density patterns independent of a substrate type. To realize the full potential of this method, especially for EUV proximity printing and interference lithography, a reliable technology for manufacturing of the transmission masks and gratings should be available. In this paper we present a development of broadband amplitude transmission masks and gratings for extreme ultraviolet and soft X-ray lithography based on free-standing niobium membranes. In comparison with a standard silicon nitride based technology the transmission masks demonstrate high contrast not only for in-band EUV (13.5 nm) radiation but also for wavelengths below Si L-absorption edge (12.4 nm). The masks and filters with free standing areas up to 1000 × 1000 μm 2 and 100 nm to 300 nm membrane thicknesses are shown. Electron beam structuring of an absorber layer with dense line and dot patterns with sub-50 nm structures is demonstrated. Diffractive and filtering properties of obtained structures are examined with EUV radiation from a gas discharge plasma source. - Highlights: ► Broadband transmission masks for EUV proximity and interference lithography. ► Technology for free standing niobium membranes with areas up to 1 mm 2 . ► High density patterns with periods of 100 nm and structure sizes below 40 nm. ► Measured diffraction efficiency at 11 nm is in agreement with the theory. ► Produced masks can be effectively used with wavelengths between 6 nm and 17 nm.

Community Broadband Networks and the Opportunity for E-Government Services

DEFF Research Database (Denmark)

Williams, Idongesit

2017-01-01

Community Broadband Networks (CBN) facilitate Broadband connectivity in underserved areas in many countries. The lack of Broadband connectivity is one of the reasons for the slow diffusion of e-government services in many countries.This article explains how CBNs can be enabled by governments...... to facilitate the delivery of e–government services in underserved areas in the developed and developing countries.The Community Based Broadband Mobilization (CBNM) models are used as explanatory tools....

High-power broad-band tunable microwave oscillator, driven by REB in plasma

Energy Technology Data Exchange (ETDEWEB)

Kuzelev, M V; Loza, O T; Ponomarev, A V; Rukhadze, A A; Strel` kov, P S; Shkvarunets, A G; Ulyanov, D K [General Physics Inst. of Russian Academy of Sciences, Moscow (Russian Federation)

1997-12-31

The radiation spectra of a plasma relativistic broad-band microwave oscillator were measured. A hollow relativistic electron beam (REB) was injected into the plasma waveguide, consisting of annular plasma in a circular metal waveguide. The radiation spectra were measured by means of a calorimeter-spectrometer with a large cross section in the band of 3-39 GHz. The mean frequency was tunable in the band of 20-27 GHz, the spectrum width was 5-25 GHz with a power level of 40-85 MW. Calculations were carried out based on non-linear theory, taking into account electromagnetic noise amplification due to REB injection into the plasma waveguide. According to the theory the radiation regime should change from the single-particle regime to the collective regime when the plasma density and the gap between the annular plasma and REB are increased. Comparison of the experimental results with the non-linear theory explains some peculiarities of the measured spectrum. (author). 4 figs., 2 refs.

Metal oxide-based gas sensor and microwave broad-band measurements: an innovative approach to gas sensing

International Nuclear Information System (INIS)

Jouhannaud, J; Rossignol, J; Stuerga, D

2007-01-01

We outline the development of a gas sensor using microwave technology (0.3 MHz to 3 GHz). The sensor is a coaxial structure into which is introduced a sensitive material. An electromagnetic field (microwave), sent out through the sensor by a vectorial network analyzer, solicits the sensitive material exposed to a gas. The observed variation in the sensor response is due to the variation in the adsorption of this gas. SrTiO 3 , demonstrated to be the highly sensitive to water vapour, is exposed to different gases (saturated vapour of water, ethanol and toluene). The response of the sensor is quantitative and typical for each gas. This method of measurement leads to the development of an alternative to the current gas sensor

Broadband spectral observation of a dMe star radio flare

International Nuclear Information System (INIS)

Guedel, M.; Benz, A.O.; Fuerst, E.; Simett, G.M.; Davis, R.J.

1989-01-01

A flare on the dMe star AD Leonis was simultaneously observed with the radio telescopes in Effelsberg, Jodrell Bank, and Arecibo using spectrometers at 1665, 166 and 1415 MHz with bandwidths of 25, 100 and 40 MHz respectively. The time coincidence confirms the stellar origin of the radiation. The flare emission was resolved into a multitude of broadband pulsations. The e-folding rise and decay times were of the order of the time resolution of the Effelsberg data (125 ms), or less. The circular polarization was ∼ 100%. Similar bursts, but 4 orders of magnitude less powerful, have been observed from the sun at lower frequencies

Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

Science.gov (United States)

Halim, Dunant; Cheng, Li; Su, Zhongqing

2011-03-01

The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

Semiconductor Quantum Dash Broadband Emitters: Modeling and Experiments

KAUST Repository

Khan, Mohammed Zahed Mustafa

2013-01-01

multi-disciplinary field applications such as biomedical imaging and sensing, general lighting and internet and mobile phone connectivity. In general, most commercial broadband light sources relies on complex systems for broadband light generation which

Passive (self-powered) fiber-optic sensors

International Nuclear Information System (INIS)

McElhaney, S.A.; Falter, D.D.; Todd, R.A.; Simpson, M.L.; Mihalczo, J.T.

1992-01-01

ORNL is developing new group of fiber-optic sensors for characterizing physical aspects such as ambient temperature. These sensors exploit the inherent property of thermographic materials that the lifetime and/or intensity of the emitted fluorescence decreases with increasing temperature. Unlike current fluorescent temperature sensors that use a light source for excitation, these sensors are totally passive (self-powered) and use either an embedded or external radiation source. A proof-of-principle temperature sensor was developed, based on this concept, using a well-known thermographic material, magnesium fluorogermanate. Experimental results showed that the radiation-induced fluorescence resulted in an intensity change but no significant decay rate change with increasing temperature

Development and radiation evaluation of mobile station for personnel monitoring system based on indigenous plastic scintillator sensor rods

International Nuclear Information System (INIS)

Chaudhary, H.S.; Parihar, A.; Senwar, K.R.; Prakash, V.; Rathore, A.S.

2018-01-01

The Mobile Station for Personnel Monitoring (MSPM) system has been designed and developed for rapid screening of personnel with respect to radiation contamination during nuclear or radiological emergency; it can also be used for prevention of illicit movement of radioactive sources. The objective was to develop a modular, transportable and easily deployable gamma portal monitoring system based on indigenous DLJ developed plastic scintillator sensors. The Gamma radiation response of the system is presented here

Techno-economic evaluation of broadband access technologies

DEFF Research Database (Denmark)

Sigurdsson, Halldór Matthias; Skouby, Knud Erik

2005-01-01

Broadband for all is an essential element in the EU policy concerning the future of ICT-based society. The overall purpose of this paper is to present a model for evaluation of different broadband access technologies and to present some preliminary results based on the model that has been carried...

Dust radiative forcing in snow of the Upper Colorado River Basin: 1. A 6 year record of energy balance, radiation, and dust concentrations

Science.gov (United States)

Painter, Thomas H.; Skiles, S. Mckenzie; Deems, Jeffrey S.; Bryant, Ann C.; Landry, Christopher C.

2012-07-01

Dust in snow accelerates snowmelt through its direct reduction of snow albedo and its further indirect reduction of albedo by accelerating the growth of snow grains. Since the westward expansion of the United States that began in the mid-19th century, the mountain snow cover of the Colorado River Basin has been subject to five-fold greater dust loading, largely from the Colorado Plateau and Great Basin. Radiative forcing of snowmelt by dust is not captured by conventional micrometeorological measurements, and must be monitored by a more comprehensive suite of radiation instruments. Here we present a 6 year record of energy balance and detailed radiation measurements in the Senator Beck Basin Study Area, San Juan Mountains, Colorado, USA. Data include broadband irradiance, filtered irradiance, broadband reflected flux, filtered reflected flux, broadband and visible albedo, longwave irradiance, wind speed, relative humidity, and air temperatures. The gradient of the snow surface is monitored weekly and used to correct albedo measurements for geometric effects. The snow is sampled weekly for dust concentrations in plots immediately adjacent to each tower over the melt season. Broadband albedo in the last weeks of snow cover ranged from 0.33 to 0.55 across the 6 years and two sites. Total end of year dust concentration in the top 3 cm of the snow column ranged from 0.23 mg g-1 to 4.16 mg g-1. These measurements enable monitoring and modeling of dust and climate-driven snowmelt forcings in the Upper Colorado River Basin.

Data Release of UV to Submillimeter Broadband Fluxes for Simulated Galaxies from the EAGLE Project

Science.gov (United States)

Camps, Peter; Trčka, Ana; Trayford, James; Baes, Maarten; Theuns, Tom; Crain, Robert A.; McAlpine, Stuart; Schaller, Matthieu; Schaye, Joop

2018-02-01

We present dust-attenuated and dust emission fluxes for sufficiently resolved galaxies in the EAGLE suite of cosmological hydrodynamical simulations, calculated with the SKIRT radiative transfer code. The post-processing procedure includes specific components for star formation regions, stellar sources, and diffuse dust and takes into account stochastic heating of dust grains to obtain realistic broadband fluxes in the wavelength range from ultraviolet to submillimeter. The mock survey includes nearly half a million simulated galaxies with stellar masses above {10}8.5 {M}ȯ across six EAGLE models. About two-thirds of these galaxies, residing in 23 redshift bins up to z = 6, have a sufficiently resolved metallic gas distribution to derive meaningful dust attenuation and emission, with the important caveat that the same dust properties were used at all redshifts. These newly released data complement the already publicly available information about the EAGLE galaxies, which includes intrinsic properties derived by aggregating the properties of the smoothed particles representing matter in the simulation. We further provide an open-source framework of Python procedures for post-processing simulated galaxies with the radiative transfer code SKIRT. The framework allows any third party to calculate synthetic images, spectral energy distributions, and broadband fluxes for EAGLE galaxies, taking into account the effects of dust attenuation and emission.

Identifying Broadband Rotational Spectra with Neural Networks

Science.gov (United States)

Zaleski, Daniel P.; Prozument, Kirill

2017-06-01

A typical broadband rotational spectrum may contain several thousand observable transitions, spanning many species. Identifying the individual spectra, particularly when the dynamic range reaches 1,000:1 or even 10,000:1, can be challenging. One approach is to apply automated fitting routines. In this approach, combinations of 3 transitions can be created to form a "triple", which allows fitting of the A, B, and C rotational constants in a Watson-type Hamiltonian. On a standard desktop computer, with a target molecule of interest, a typical AUTOFIT routine takes 2-12 hours depending on the spectral density. A new approach is to utilize machine learning to train a computer to recognize the patterns (frequency spacing and relative intensities) inherit in rotational spectra and to identify the individual spectra in a raw broadband rotational spectrum. Here, recurrent neural networks have been trained to identify different types of rotational spectra and classify them accordingly. Furthermore, early results in applying convolutional neural networks for spectral object recognition in broadband rotational spectra appear promising. Perez et al. "Broadband Fourier transform rotational spectroscopy for structure determination: The water heptamer." Chem. Phys. Lett., 2013, 571, 1-15. Seifert et al. "AUTOFIT, an Automated Fitting Tool for Broadband Rotational Spectra, and Applications to 1-Hexanal." J. Mol. Spectrosc., 2015, 312, 13-21. Bishop. "Neural networks for pattern recognition." Oxford university press, 1995.

Dimensional Measurements under High Radiation with Optical Fibre Sensors based on White Light Interferometry - Report on Irradiation Tests

International Nuclear Information System (INIS)

Cheymol, G.; Caron, N.; Gusarov, A.; Gaillot, S.; Destouches, C.

2013-06-01

Abstract-Optical fibre sensors (OFS) can bring substantial advantages over conventional sensing approaches for in-situ measurement in fission Material Testing Reactors (MTRs) and other nuclear research or industrial facilities: easy remote sensing, possibilities of multiplexing, passive operation, low sensitivity to electromagnetic interference, compact size, high resolution and accuracy even under high radiation dose and high temperature, once necessary adaptations have been achieved. In this paper firstly we remind the three undesired effects of high level of irradiation on OFS: radiation induced attenuation, radio luminescence and compaction due to fast neutrons. Then we present two types of sensor that we develop: elongation Fabry Perot sensor - jointly with SCK.CEN - and Michelson type displacement sensor; they both rely on white light interferometry to retrieve the desired measurement. We report the results of irradiation of Fabry-Perot sensors in the core of BR2 material testing reactor in Mol (Belgium), under intense neutron-gamma flux and at high temperature. Six Fabry Perot fibre optics sensors are mounted on a support insensitive to radiation. The objective is to test the survival and the drift of the sensors. The temperature is maintained steady at 200 deg. C during 22 days then the temperature is increased up to 390 deg. C. Among five sensors built according to nominal scheme, four are still alive at the end of the cycle and three show a low drift of 1 to 4 μm. These results show a clear progress compared to the previous irradiation and make it possible to consider the use of these sensors in real tests of material in MTR reactor. However, improvement in the robustness of the interfaces is still necessary. The next part is devoted to the measurement of displacements perpendicular to the direction of the lead-in fibre, of interest for small room environments where the fibre cannot make a 90 deg. turn. The optical scheme is based on the Michelson

FR4-based electromagnetic energy harvester for wireless sensor nodes

Science.gov (United States)

Hatipoglu, G.; Ürey, H.

2010-01-01

Electromagnetic (EM) energy harvesting seems to be one of the most promising ways to power wireless sensors in a wireless sensor network. In this paper, FR4, the most commonly used PCB material, is utilized as a mechanical vibrating structure for EM energy harvesting for body-worn sensors and intelligent tire sensors, which involve impact loadings. FR4 can be a better material for such applications compared to silicon MEMS devices due to lower stiffness and broadband response. In order to demonstrate FR4 performance and broadband response, three moving magnet type EM generator designs are developed and investigated throughout the paper. A velocity-damped harvester simulation model is first developed, including a detailed magnetic model and the magnetic damping effects. The numerical results agree well with the experimental results. Human running acceleration at the hip area that is obtained experimentally is simulated in order to demonstrate system performance, which results in a scavenged power of about 40 µW with 15 m s-2 acceleration input. The designed FR4 energy scavengers with mechanical stoppers implemented are particularly well suited for nearly periodic and non-sinusoidal high- g excitations with rich harmonic content. For the intelligent tire applications, a special compact FR4 scavenger is designed that is able to withstand large shocks and vibrations due to mechanical shock stoppers built into the structure. Using our design, 0.4 mW power across a load resistance at off-resonance operation is obtained in shaker experiments. In the actual operation, the tangential accelerations as a result of the tire-road contact are estimated to supply power around 1 mW with our design, which is sufficient for powering wireless tire sensors. The normalized power density (NPD) of the designed actuators compares favorably with most actuators reported in the literature.

FR4-based electromagnetic energy harvester for wireless sensor nodes

International Nuclear Information System (INIS)

Hatipoglu, G; Ürey, H

2010-01-01

Electromagnetic (EM) energy harvesting seems to be one of the most promising ways to power wireless sensors in a wireless sensor network. In this paper, FR4, the most commonly used PCB material, is utilized as a mechanical vibrating structure for EM energy harvesting for body-worn sensors and intelligent tire sensors, which involve impact loadings. FR4 can be a better material for such applications compared to silicon MEMS devices due to lower stiffness and broadband response. In order to demonstrate FR4 performance and broadband response, three moving magnet type EM generator designs are developed and investigated throughout the paper. A velocity-damped harvester simulation model is first developed, including a detailed magnetic model and the magnetic damping effects. The numerical results agree well with the experimental results. Human running acceleration at the hip area that is obtained experimentally is simulated in order to demonstrate system performance, which results in a scavenged power of about 40 µW with 15 m s −2 acceleration input. The designed FR4 energy scavengers with mechanical stoppers implemented are particularly well suited for nearly periodic and non-sinusoidal high- g excitations with rich harmonic content. For the intelligent tire applications, a special compact FR4 scavenger is designed that is able to withstand large shocks and vibrations due to mechanical shock stoppers built into the structure. Using our design, 0.4 mW power across a load resistance at off-resonance operation is obtained in shaker experiments. In the actual operation, the tangential accelerations as a result of the tire–road contact are estimated to supply power around 1 mW with our design, which is sufficient for powering wireless tire sensors. The normalized power density (NPD) of the designed actuators compares favorably with most actuators reported in the literature

Vapor transport deposition of large-area polycrystalline CdTe for radiation image sensor application

Energy Technology Data Exchange (ETDEWEB)

Yang, Keedong; Cha, Bokyung; Heo, Duchang; Jeon, Sungchae [Korea Electrotechnology Research Institute, 111 Hanggaul-ro, Ansan-si, Gyeonggi-do 426-170 (Korea, Republic of)

2014-07-15

Vapor transport deposition (VTD) process delivers saturated vapor to substrate, resulting in high-throughput and scalable process. In addition, VTD can maintain lower substrate temperature than close-spaced sublimation (CSS). The motivation of this work is to adopt several advantages of VTD for radiation image sensor application. Polycrystalline CdTe films were obtained on 300 mm x 300 mm indium tin oxide (ITO) coated glass. The polycrystalline CdTe film has columnar structure with average grain size of 3 μm ∝ 9 μm, which can be controlled by changing the substrate temperature. In order to analyze electrical and X-ray characteristics, ITO-CdTe-Al sandwich structured device was fabricated. Effective resistivity of the polycrystalline CdTe film was ∝1.4 x 10{sup 9}Ωcm. The device was operated under hole-collection mode. The responsivity and the μτ product estimated to be 6.8 μC/cm{sup 2}R and 5.5 x 10{sup -7} cm{sup 2}/V. The VTD can be a process of choice for monolithic integration of CdTe thick film for radiation image sensor and CMOS/TFT circuitry. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Optical depth retrievals from Delta-T SPN1 measurements of broadband solar irradiance at ground

Science.gov (United States)

Estelles, Victor; Serrano, David; Segura, Sara; Wood, John; Webb, Nick

2016-04-01

The SPN1 radiometer, manufactured by Delta-T Devices Ltd., is an instrument designed for the measurement of global solar irradiance and its components (diffuse, direct) at ground level. In the present study, the direct irradiance component has been used to retrieve an effective total optical depth, by applying the Beer-Lambert law to the broadband measurements. The results have been compared with spectral total optical depths derived from two Cimel CE318 and Prede POM01 sun-sky radiometers, located at the Burjassot site in Valencia (Spain), during years 2013 - 2015. The SPN1 is an inexpensive and versatile instrument for the measurement of the three components of the solar radiation without any mobile part and without any need to azimuthally align the instrument to track the sun (http://www.delta-t.co.uk). The three components of the solar radiation are estimated from a combination of measurements performed by 7 different miniature thermopiles. In turn, the Beer-Lambert law has been applied to the broadband direct solar component to obtain an effective total optical depth, representative of the total extinction in the atmosphere. For the assessment of the total optical depth values retrieved with the SPN1, two different sun-sky radiometers (Cimel CE318 and Prede POM01L) have been employed. Both instruments belong to the international networks AERONET and SKYNET. The modified SUNRAD package has been applied in both Cimel and Prede instruments. Cloud affected data has been removed by applying the Smirnov cloud-screening procedure in the SUNRAD algorithm. The broadband SPN1 total optical depth has been analysed by comparison with the spectral total optical depth from the sun-sky radiometer measurements at wavelengths 440, 500, 675, 870 and 1020 nm. The slopes and intercepts have been estimated to be 0.47 - 0.98 and 0.055 - 0.16 with increasing wavelength. The average correlation coefficients and RMSD were 0.80 - 0.83 and 0.034 - 0.036 for all the channels. The

Radiation budget studies using collocated observations from advanced Very High Resolution Radiometer, High-Resolution Infrared Sounder/2, and Earth Radiation Budget Experiment instruments

Science.gov (United States)

Ackerman, Steven A.; Frey, Richard A.; Smith, William L.

1992-01-01

Collocated observations from the Advanced Very High Resolution Radiometer (AVHRR), High-Resolution Infrared Sounder/2 (HIRS/2), and Earth Radiation Budget Experiment (ERBE) instruments onboard the NOAA 9 satellite are combined to describe the broadband and spectral radiative properties of the earth-atmosphere system. Broadband radiative properties are determined from the ERBE observations, while spectral properties are determined from the HIRS/2 and AVHRR observations. The presence of clouds, their areal coverage, and cloud top pressure are determined from a combination of the HIRS/2 and the AVHRR observations. The CO2 slicing method is applied to the HIRS/2 to determine the presence of upper level clouds and their effective emissivity. The AVHRR data collocated within the HIRS/2 field of view are utilized to determine the uniformity of the scene and retrieve sea surface temperature. Changes in the top of the atmosphere longwave and shortwave radiative energy budgets, and the spectral distribution of longwave radiation are presented as a function of cloud amount and cloud top pressure. The radiative characteristics of clear sky conditions over oceans are presented as a function of sea surface temperature and atmospheric water vapor structure.

Bio-inspired heterogeneous composites for broadband vibration mitigation.

Science.gov (United States)

Chen, Yanyu; Wang, Lifeng

2015-12-08

Structural biological materials have developed heterogeneous and hierarchical architectures that are responsible for the outstanding performance to provide protection against environmental threats including static and dynamic loading. Inspired by this observation, this research aims to develop new material and structural concepts for broadband vibration mitigation. The proposed composite materials possess a two-layered heterogeneous architecture where both layers consist of high-volume platelet-shape reinforcements and low-volume matrix, similar to the well-known "brick and mortar" microstructure of biological composites. Using finite element method, we numerically demonstrated that broadband wave attenuation zones can be achieved by tailoring the geometric features of the heterogeneous architecture. We reveal that the resulting broadband attenuation zones are gained by directly superimposing the attenuation zones in each constituent layer. This mechanism is further confirmed by the investigation into the phonon dispersion relation of each layer. Importantly, the broadband wave attenuation capability will be maintained when the mineral platelet orientation is locally manipulated, yet a contrast between the mineral platelet concentrations of the two constituent layers is essential. The findings of this work will provide new opportunities to design heterogeneous composites for broadband vibration mitigation and impact resistance under mechanically challenging environmental conditions.

Broadband set-top box using MAP-CA processor

Science.gov (United States)

Bush, John E.; Lee, Woobin; Basoglu, Chris

2001-12-01

Advances in broadband access are expected to exert a profound impact in our everyday life. It will be the key to the digital convergence of communication, computer and consumer equipment. A common thread that facilitates this convergence comprises digital media and Internet. To address this market, Equator Technologies, Inc., is developing the Dolphin broadband set-top box reference platform using its MAP-CA Broadband Signal ProcessorT chip. The Dolphin reference platform is a universal media platform for display and presentation of digital contents on end-user entertainment systems. The objective of the Dolphin reference platform is to provide a complete set-top box system based on the MAP-CA processor. It includes all the necessary hardware and software components for the emerging broadcast and the broadband digital media market based on IP protocols. Such reference design requires a broadband Internet access and high-performance digital signal processing. By using the MAP-CA processor, the Dolphin reference platform is completely programmable, allowing various codecs to be implemented in software, such as MPEG-2, MPEG-4, H.263 and proprietary codecs. The software implementation also enables field upgrades to keep pace with evolving technology and industry demands.

Radiation Budget Instrument (RBI) for JPSS-2

Science.gov (United States)

Georgieva, Elena; Priestley, Kory; Dunn, Barry; Cageao, Richard; Barki, Anum; Osmundsen, Jim; Turczynski, Craig; Abedin, Nurul

2015-01-01

Radiation Budget Instrument (RBI) will be one of five instruments flying aboard the JPSS-2 spacecraft, a polar-orbiting sun-synchronous satellite in Low Earth Orbit. RBI is a passive remote sensing instrument that will follow the successful legacy of the Clouds and Earth's Radiant Energy System (CERES) instruments to make measurement of Earth's short and longwave radiation budget. The goal of RBI is to provide an independent measurement of the broadband reflected solar radiance and Earth's emitted thermal radiance by using three spectral bands (Shortwave, Longwave, and Total) that will have the same overlapped point spread function (PSF) footprint on Earth. To ensure precise NIST-traceable calibration in space the RBI sensor is designed to use a visible calibration target (VCT), a solar calibration target (SCT), and an infrared calibration target (ICT) containing phase change cells (PCC) to enable on-board temperature calibration. The VCT is a thermally controlled integrating sphere with space grade Spectralon covering the inner surface. Two sides of the sphere will have fiber-coupled laser diodes in the UV to IR wavelength region. An electrical substitution radiometer on the integrating sphere will monitor the long term stability of the sources and the possible degradation of the Spectralon in space. In addition the radiometric calibration operations will use the Spectralon diffusers of the SCT to provide accurate measurements of Solar degradation. All those stable on-orbit references will ensure that calibration stability is maintained over the RBI sensor lifetime. For the preflight calibration the RBI will view five calibration sources - two integrating spheres and three CrIS (Cross-track Infrared Sounder ) -like blackbodies whose outputs will be validated with NIST calibration approach. Thermopile are the selected detectors for the RBI. The sensor has a requirement to perform lunar calibration in addition to solar calibration in space in a way similar to CERES

A broadband helical saline water liquid antenna for wearable systems

Science.gov (United States)

Li, Gaosheng; Huang, Yi; Gao, Gui; Yang, Cheng; Lu, Zhonghao; Liu, Wei

2018-04-01

A broadband helical liquid antenna made of saline water is proposed. A transparent hollow support is employed to fabricate the antenna. The rotation structure is fabricated with a thin flexible tube. The saline water with a concentration of 3.5% can be injected into or be extracted out from the tube to change the quantity of the solution. Thus, the tunability of the radiation pattern could be realised by applying the fluidity of the liquid. The radiation feature of the liquid antenna is compared with that of a metal one, and fairly good agreement has been achieved. Furthermore, three statements of the radiation performance corresponding to the ratio of the diameter to the wavelength of the helical saline water antenna have been proposed. It has been found that the resonance frequency increases when the length of the feeding probe or the radius of the vertical part of the liquid decreases. The fractional bandwidth can reach over 20% with a total height of 185 mm at 1.80 GHz. The measured results indicate reasonable approximation to the simulated. The characteristics of the liquid antenna make it a good candidate for various wireless applications, especially the wearable systems.

Surface Effects in Segmented Silicon Sensors

OpenAIRE

Kopsalis, Ioannis

2017-01-01

Silicon detectors in Photon Science and Particle Physics require silicon sensors with very demanding specifications. New accelerators like the European X-ray Free Electron Laser (EuXFEL) and the High Luminosity upgrade of the Large Hadron Collider (HL-LHC), pose new challenges for silicon sensors, especially with respect to radiation hardness. High radiation doses and fluences damage the silicon crystal and the SiO2 layers at the surface, thus changing the sensor properties and limiting their...

Silicon sensor technologies for ATLAS IBL upgrade

CERN Document Server

Grenier, P; The ATLAS collaboration

2011-01-01

New pixel sensors are currently under development for ATLAS Upgrades. The first upgrade stage will consist in the construction of a new pixel layer that will be installed in the detector during the 2013 LHC shutdown. The new layer (Insertable-B-Layer, IBL) will be inserted between the inner most layer of the current pixel detector and the beam pipe at a radius of 3.2cm. The expected high radiation levels require the use of radiation hard technology for both the front-end chip and the sensor. Two different pixel sensor technologies are envisaged for the IBL. The sensor choice will occur in July 2011. One option is developed by the ATLAS Planar Pixel Sensor (PPS) Collaboration and is based on classical n-in-n planar silicon sensors which have been used for the ATLAS Pixel detector. For the IBL, two changes were required: The thickness was reduced from 250 um to 200 um to improve the radiation hardness. In addition, so-called "slim edges" were designed to reduce the inactive edge of the sensors from 1100 um to o...

Large area CMOS image sensors

International Nuclear Information System (INIS)

Turchetta, R; Guerrini, N; Sedgwick, I

2011-01-01

CMOS image sensors, also known as CMOS Active Pixel Sensors (APS) or Monolithic Active Pixel Sensors (MAPS), are today the dominant imaging devices. They are omnipresent in our daily life, as image sensors in cellular phones, web cams, digital cameras, ... In these applications, the pixels can be very small, in the micron range, and the sensors themselves tend to be limited in size. However, many scientific applications, like particle or X-ray detection, require large format, often with large pixels, as well as other specific performance, like low noise, radiation hardness or very fast readout. The sensors are also required to be sensitive to a broad spectrum of radiation: photons from the silicon cut-off in the IR down to UV and X- and gamma-rays through the visible spectrum as well as charged particles. This requirement calls for modifications to the substrate to be introduced to provide optimized sensitivity. This paper will review existing CMOS image sensors, whose size can be as large as a single CMOS wafer, and analyse the technical requirements and specific challenges of large format CMOS image sensors.

Observations involving broadband impedance modelling

Energy Technology Data Exchange (ETDEWEB)

Berg, J S [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

1996-08-01

Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impedance. This paper discusses three aspects of broadband impedance modelling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f. cavity. The last is a discussion of requirements for the mathematical form of an impedance which follow from the general properties of impedances. (author)

Observations involving broadband impedance modelling

International Nuclear Information System (INIS)

Berg, J.S.

1995-08-01

Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impendance. This paper discusses three aspects of broadband impendance modeling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f cavity. The last is a discussion of requirements for the mathematical form of an impendance which follow from the general properties of impendances

Development of Radiation-hard Bandgap Reference and Temperature Sensor in CMOS 130 nm Technology

CERN Document Server

Kuczynska, Marika; Bugiel, Szymon; Firlej, Miroslaw; Fiutowski, Tomasz; Idzik, Marek; Michelis, Stefano; Moron, Jakub; Przyborowski, Dominik; Swientek, Krzysztof

2015-01-01

A stable reference voltage (or current) source is a standard component of today's microelectronics systems. In particle physics experiments such reference is needed in spite of harsh ionizing radiation conditions, i.e. doses exceeding 100 Mrads and fluences above 1e15 n/cm2. After such radiation load a bandgap reference using standard p-n junction of bipolar transistor does not work properly. Instead of using standard p-n junctions, two enclosed layout transistor (ELTMOS) structures are used to create radiation-hard diodes: the ELT bulk diode and the diode obtained using the ELTMOS as dynamic threshold transistor (DTMOS). In this paper we have described several sub-1V references based on ELTMOS bulk diode and DTMOS based diode, using CMOS 130 nm process. Voltage references the structures with additional PTAT (Proportional To Absolute Temperature) output for temperature measurements were also designed. We present and compare post-layout simulations of the developed bandgap references and temperature sensors, w...

CMOS pixel sensors on high resistive substrate for high-rate, high-radiation environments

Energy Technology Data Exchange (ETDEWEB)

Hirono, Toko, E-mail: thirono@uni-bonn.de [Physikalisches Institute der Universität Bonn, Bonn (Germany); Barbero, Marlon; Breugnon, Patrick; Godiot, Stephanie [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Gonella, Laura; Hemperek, Tomasz; Hügging, Fabian; Krüger, Hans [Physikalisches Institute der Universität Bonn, Bonn (Germany); Liu, Jian; Pangaud, Patrick [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Peric, Ivan [IPE, Karlsruher Institut für Technologie, Karlsruhe (Germany); Pohl, David-Leon [Physikalisches Institute der Universität Bonn, Bonn (Germany); Rozanov, Alexandre [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Rymaszewski, Piotr [Physikalisches Institute der Universität Bonn, Bonn (Germany); Wang, Anqing [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Wermes, Norbert [Physikalisches Institute der Universität Bonn, Bonn (Germany)

2016-09-21

A depleted CMOS active pixel sensor (DMAPS) has been developed on a substrate with high resistivity in a high voltage process. High radiation tolerance and high time resolution can be expected because of the charge collection by drift. A prototype of DMAPS was fabricated in a 150 nm process by LFoundry. Two variants of the pixel layout were tested, and the measured depletion depths of the variants are 166 μm and 80 μm. We report the results obtained with the prototype fabricated in this technology.

Infrared radiation models for atmospheric methane

Science.gov (United States)

Cess, R. D.; Kratz, D. P.; Caldwell, J.; Kim, S. J.

1986-01-01

Mutually consistent line-by-line, narrow-band and broad-band infrared radiation models are presented for methane, a potentially important anthropogenic trace gas within the atmosphere. Comparisons of the modeled band absorptances with existing laboratory data produce the best agreement when, within the band models, spurious band intensities are used which are consistent with the respective laboratory data sets, but which are not consistent with current knowledge concerning the intensity of the infrared fundamental band of methane. This emphasizes the need for improved laboratory band absorptance measurements. Since, when applied to atmospheric radiation calculations, the line-by-line model does not require the use of scaling approximations, the mutual consistency of the band models provides a means of appraising the accuracy of scaling procedures. It is shown that Curtis-Godson narrow-band and Chan-Tien broad-band scaling provide accurate means of accounting for atmospheric temperature and pressure variations.

Transition undulator radiation as bright infrared sources

Energy Technology Data Exchange (ETDEWEB)

Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

1995-02-01

Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

Network Coding on Heterogeneous Multi-Core Processors for Wireless Sensor Networks

Science.gov (United States)

Kim, Deokho; Park, Karam; Ro, Won W.

2011-01-01

While network coding is well known for its efficiency and usefulness in wireless sensor networks, the excessive costs associated with decoding computation and complexity still hinder its adoption into practical use. On the other hand, high-performance microprocessors with heterogeneous multi-cores would be used as processing nodes of the wireless sensor networks in the near future. To this end, this paper introduces an efficient network coding algorithm developed for the heterogenous multi-core processors. The proposed idea is fully tested on one of the currently available heterogeneous multi-core processors referred to as the Cell Broadband Engine. PMID:22164053

An Underwater Acoustic Vector Sensor with High Sensitivity and Broad Band

Directory of Open Access Journals (Sweden)

Hu Zhang

2014-05-01

Full Text Available Recently, acoustic vector sensor that use accelerators as sensing elements are widely used in underwater acoustic engineering, but the sensitivity of which at low frequency band is usually lower than -220 dB. In this paper, using a piezoelectric trilaminar optimized low frequency sensing element, we designed a high sensitivity internal placed ICP piezoelectric accelerometer as sensing element. Through structure optimization, we made a high sensitivity, broadband, small scale vector sensor. The working band is 10-2000 Hz, sound pressure sensitivity is -185 dB (at 100 Hz, outer diameter is 42 mm, length is 80 mm.

Identification of radiation induced dark current sources in pinned photodiode CMOS image sensors

International Nuclear Information System (INIS)

Goiffon, V.; Virmontois, C.; Magnan, P.; Cervantes, P.; Place, S.; Estribeau, M.; Martin-Gonthier, P.; Gaillardin, M.; Girard, S.; Paillet, P.

2012-01-01

This paper presents an investigation of Total Ionizing Dose (TID) induced dark current sources in Pinned Photodiodes (PPD) CMOS Image Sensors based on pixel design variations. The influence of several layout parameters is studied. Only one parameter is changed at a time enabling the direct evaluation of its contribution to the observed device degradation. By this approach, the origin of radiation induced dark current in PPD is localized on the pixel layout. The PPD peripheral shallow trench isolation does not seem to play a role in the degradation. The PPD area and a transfer gate contribution independent of the pixel dimensions appear to be the main sources of the TID induced dark current increase. This study also demonstrates that applying a negative voltage on the transfer gate during integration strongly reduces the radiation induced dark current. (authors)

Update on scribe–cleave–passivate (SCP) slim edge technology for silicon sensors: Automated processing and radiation resistance

Energy Technology Data Exchange (ETDEWEB)

Fadeyev, V., E-mail: fadeyev@ucsc.edu [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States); Ely, S.; Galloway, Z.; Ngo, J.; Parker, C.; Sadrozinski, H.F.-W. [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States); Christophersen, M.; Phlips, B.F. [U.S. Naval Research Laboratory, Code 7654, 4555 Overlook Avenue, Southwest Washington, DC 20375 (United States); Pellegrini, G.; Rafi, J.M.; Quirion, D. [Instituto de Microelectrónica de Barcelona, IMB-CNM-CSIC, Bellaterra, Barcelona (Spain); Dalla Betta, G.-F. [INFN and University of Trento, Via Sommarive, 14, 38123 Povo di Trento (Italy); Boscardin, M. [Fondazione Bruno Kessler, Via Sommarive, 18, 38123 Povo di Trento (Italy); Casse, G. [Department of Physics, University of Liverpool, O. Lodge Laboratory, Oxford Street, Liverpool L69 7ZE (United Kingdom); Gorelov, I.; Hoeferkamp, M.; Metcalfe, J.; Seidel, S. [Department of Physics and Astronomy, University of New Mexico, MSC 07 4220, 1919 Lomas Boulevard NE, Albuquerque, NM 87131 (United States); Gaubas, E.; Ceponis, T. [Institute of Applied Research, Vilnius University, Sauletekio 9, LT-10222 Vilnius (Lithuania); and others

2014-11-21

We pursue scribe–cleave–passivate (SCP) technology for making “slim edge” sensors. The goal is to reduce the inactive region at the periphery of the devices while maintaining their performance. In this paper we report on two aspects of the current efforts. The first one involves fabrication options for mass production. We describe the automated cleaving tests and a simplified version of SCP post-processing of n-type devices. Another aspect is the radiation resistance of the passivation. We report on the radiation tests of n- and p-type devices with protons and neutrons.

Application of «Sensor signal analysis network» complex for distributed, time synchronized analysis of electromagnetic radiation

Science.gov (United States)

Mochalov, Vladimir; Mochalova, Anastasia

2017-10-01

The paper considers a developing software-hardware complex «Sensor signal analysis network» for distributed and time synchronized analysis of electromagnetic radiations. The areas of application and the main features of the complex are described. An example of application of the complex to monitor natural electromagnetic radiation sources is considered based on the data recorded in VLF range. A generalized functional scheme of stream analysis of signals by a complex functional node is suggested and its application for stream detection of atmospherics, whistlers and tweaks is considered.

Combined Instrumentation Package COMARS+ for the ExoMars Schiaparelli Lander

Science.gov (United States)

Gülhan, Ali; Thiele, Thomas; Siebe, Frank; Kronen, Rolf

2018-02-01

In order to measure aerothermal parameters on the back cover of the ExoMars Schiaparelli lander the instrumentation package COMARS+ was developed by DLR. Consisting of three combined aerothermal sensors, one broadband radiometer sensor and an electronic box the payload provides important data for future missions. The aerothermal sensors called COMARS combine four discrete sensors measuring static pressure, total heat flux, temperature and radiative heat flux at two specific spectral bands. The infrared radiation in a broadband spectral range is measured by the separate broadband radiometer sensor. The electronic box of the payload is used for amplification, conditioning and multiplexing of the sensor signals. The design of the payload was mainly carried out using numerical tools including structural analyses, to simulate the main mechanical loads which occur during launch and stage separation, and thermal analyses to simulate the temperature environment during cruise phase and Mars entry. To validate the design an extensive qualification test campaign was conducted on a set of qualification models. The tests included vibration and shock tests to simulate launch loads and stage separation shocks. Thermal tests under vacuum condition were performed to simulate the thermal environment of the capsule during the different flight phases. Furthermore electromagnetic compatibility tests were conducted to check that the payload is compatible with the electromagnetic environment of the capsule and does not emit electromagnetic energy that could cause electromagnetic interference in other devices. For the sensor heads located on the ExoMars back cover radiation tests were carried out to verify their radiation hardness. Finally the bioburden reduction process was demonstrated on the qualification hardware to show the compliance with the planetary protection requirements. To test the actual heat flux, pressure and infrared radiation measurement under representative conditions

Application of a Broadband Active Vibration Control System to a Helicopter Trim Panel

Science.gov (United States)

Cabell, Randolph H.; Schiller, Noah H.; Simon, Frank

2013-01-01

This paper discusses testing of a broadband active vibration control concept on an interior trim panel in a helicopter cabin mockup located at ONERA's Centre de Toulouse. The control system consisted of twelve diamond-shaped piezoelectric actuators distributed around a 1.2m x 1.2m trim panel. Accelerometers were mounted at the four vertices of each diamond. The aspect ratio of the diamond was based on the dielectric constants of the piezoelectric material in order to create an actuator-sensor pair that was collocated over a broad frequency range. This allowed robust control to be implemented using simple, low power analog electronics. Initial testing on a thick acrylic window demonstrated the capability of the controller, but actuator performance was less satisfactory when mounted on a composite sandwich trim panel. This may have been due to the orthotropic nature of the trim panel, or due to its much higher stiffness relative to the acrylic window. Insights gained from a finite element study of the actuator-sensor-structural system are discussed.

Is European Broadband Ready for Smart Grid?

DEFF Research Database (Denmark)

Balachandran, Kartheepan; Pedersen, Jens Myrup

2014-01-01

In this short paper we compare the communication requirements for three Smart Grid scenarios with the availability of broadband and mobile communication networks in Europe. We show that only in the most demanding case - where data is collected and transmitted every second - a standard GSM/GPRS co....../GPRS connection is not enough. Whereas in the less demanding scenarios it is almost all of the European households that can be covered by a standard broadband technology for use with Smart Grid.......In this short paper we compare the communication requirements for three Smart Grid scenarios with the availability of broadband and mobile communication networks in Europe. We show that only in the most demanding case - where data is collected and transmitted every second - a standard GSM...

Tunable Broadband Nanocarbon Transparent Conductor by Electrochemical Intercalation.

Science.gov (United States)

Wan, Jiayu; Xu, Yue; Ozdemir, Burak; Xu, Lisha; Sushkov, Andrei B; Yang, Zhi; Yang, Bao; Drew, Dennis; Barone, Veronica; Hu, Liangbing

2017-01-24

Optical transparent and electrical conducting materials with broadband transmission are important for many applications in optoelectronic, telecommunications, and military devices. However, studies of broadband transparent conductors and their controlled modulation are scarce. In this study, we report that reversible transmittance modulation has been achieved with sandwiched nanocarbon thin films (containing carbon nanotubes (CNTs) and reduced graphene oxide (rGO)) via electrochemical alkali-ion intercalation/deintercalation. The transmittance modulation covers a broad range from the visible (450 nm) to the infrared (5 μm), which can be achieved only by rGO rather than pristine graphene films. The large broadband transmittance modulation is understood with DFT calculations, which suggest a decrease in interband transitions in the visible range as well as a reduced reflection in the IR range upon intercalation. We find that a larger interlayer distance in few-layer rGO results in a significant increase in transparency in the infrared region of the spectrum, in agreement with experimental results. Furthermore, a reduced plasma frequency in rGO compared to few-layer graphene is also important to understand the experimental results for broadband transparency in rGO. The broadband transmittance modulation of the CNT/rGO/CNT systems can potentially lead to electrochromic and thermal camouflage applications.

VT DSL Broadband Availability by Census Block - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Wireless Broadband Availability by Census Block - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT Wireline Broadband Availability by Census Block - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

VT Cable Broadband Availability by Census Block - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Total Broadband Availability by Census Block - 12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

VT Cable Broadband Availability by Census Block - 12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

VT Detailed Broadband Availability by Census Block -12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

VT Detailed Broadband Availability by Census Block - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Detailed Broadband Availability by Census Block -12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT Detailed Broadband Availability by Census Block - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT Wireline Broadband Availability by Census Block - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT Wireless Broadband Availability by Census Block - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

VT Total Broadband Availability by Census Block - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Wireline Broadband Availability by Census Block - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Wireless Broadband Availability by Census Block - 12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

VT Total Broadband Availability by Census Block - 12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT Cable Broadband Availability by Census Block - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT Wireless Broadband Availability by Census Block - 06-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

VT Detailed Broadband Availability by Census Block - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT Total Broadband Availability by Census Block - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT DSL Broadband Availability by Census Block - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT Wireline Broadband Availability by Census Block - 12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

VT Wireless Broadband Availability by Census Block - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT DSL Broadband Availability by Census Block - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

VT Cable Broadband Availability by Census Block - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT Wireline Broadband Availability by Census Block - 12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT Cable Broadband Availability by Census Block - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

VT Wireless Broadband Availability by Census Block - 12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT DSL Broadband Availability by Census Block - 12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT Wireline Broadband Availability by Census Block - 06-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

VT Cable Broadband Availability by Census Block - 12-2011

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

VT Total Broadband Availability by Census Block - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT Detailed Broadband Availability by Census Block - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

VT DSL Broadband Availability by Census Block - 12-2012

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

VT DSL Broadband Availability by Census Block - 12-2010

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

VT Total Broadband Availability by Census Block - 06-2013

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

A Neural Network Based Intelligent Predictive Sensor for Cloudiness, Solar Radiation and Air Temperature

Science.gov (United States)

Ferreira, Pedro M.; Gomes, João M.; Martins, Igor A. C.; Ruano, António E.

2012-01-01

Accurate measurements of global solar radiation and atmospheric temperature, as well as the availability of the predictions of their evolution over time, are important for different areas of applications, such as agriculture, renewable energy and energy management, or thermal comfort in buildings. For this reason, an intelligent, light-weight and portable sensor was developed, using artificial neural network models as the time-series predictor mechanisms. These have been identified with the aid of a procedure based on the multi-objective genetic algorithm. As cloudiness is the most significant factor affecting the solar radiation reaching a particular location on the Earth surface, it has great impact on the performance of predictive solar radiation models for that location. This work also represents one step towards the improvement of such models by using ground-to-sky hemispherical colour digital images as a means to estimate cloudiness by the fraction of visible sky corresponding to clouds and to clear sky. The implementation of predictive models in the prototype has been validated and the system is able to function reliably, providing measurements and four-hour forecasts of cloudiness, solar radiation and air temperature. PMID:23202230

Metropolitan area networks: a corner stone in the broadband era

Science.gov (United States)

Ghanem, Adel

1991-02-01

Deployment of Broadband ISDN is being influenced by both a market pull and a technology push. New broadband service opportunities exist in the business and residential sectors of the market place. It is envisioned that some customers will need connections directly to broadband switches because of the high bandwidth needed for their applications. At the same time Metropolitan Area Network (MAN) systems will serve those customers with bandwidth requirements less than or equal to 150 Mbps. A given MAN will have a geographical domain to serve where it will carry out the switching tasks within this domain. While MANs couldbe designed using differentarchitecturalconcepts the setofservices expected tobeprovidedby MANs could be equivalent to thelist ofservices thatwillbe supported by the targetbroadband network. This paperpositions MANs as a major building block for Broadband networks. It also examines the evolution process ofMANs as a needed step to assure the successful deployment of these new broadband services. 2. BISDN - OVERVIEW Broadband ISDN (BISDN) is being driven into existence by both a market pull as well as a technology push. Opportunities for new valueadded services are the prime market pull for future broadband networks. These services opportunities extend beyond simple voice and low speed data applications and cover both the residential and the business sectors of the market. It is noted for instance that business customers have growing needs for sophisticated telecommunication vehicles to support their

Radiation detector. [100 A

Energy Technology Data Exchange (ETDEWEB)

Baker, P D; Hollands, D V

1975-12-04

A radiation detector is described in which the radiation is led to a sensor via a 100 A thick gold film filter, which reduces the infrared components of the irradiation to a greater extent than the ultra-violet component reaching the sensor.

A monolithic active pixel sensor for ionizing radiation using a 180 nm HV-SOI process

Energy Technology Data Exchange (ETDEWEB)

Hemperek, Tomasz; Kishishita, Tetsuichi; Krueger, Hans; Wermes, Norbert [Institute of Physics, University of Bonn, Bonn (Germany)

2016-07-01

An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on thick-180 nm High Voltage SOI technology (HV-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer. Standard FD-SOI MAPS suffer from radiation damage such as transistor threshold voltage shifts due to trapped charge in the buried oxide layer and charged interface states created at the silicon oxide boundaries (back gate effect). The X-FAB 180 nm HV-SOI technology offers an additional isolation using a deep non-depleted implant between the BOX layer and the active circuitry which mitigates this problem. Therefore we see in this technology a high potential to implement radiation-tolerant MAPS with fast charge collection. The design and measurement results from first prototypes are presented including radiation tolerance to total ionizing dose and charge collection properties of neutron irradiated samples.

A calibrated, broadband antenna for plasma RF emission measurements below 1 GHz

International Nuclear Information System (INIS)

Spence, P.D.; Rosenberg, D.; Roth, J.R.

1984-01-01

A constant impedance, constant aperture antenna can make possible broadband plasma RF emission measurements which yield relative and absolute power levels. However, good technique must be followed for the immersion of such an RF probe into plasma radiation. The authors have used a complementary conical spiral antenna to observe plasma RF emission over the frequency range 100 ≤ν≤ 1200 MHz. The RF emission was emitted by a modified Penning discharge. The RF emission from the discharge typically exhibits harmonic structure over a broad frequency range, necessitating a broadband antenna with a flat frequency response curve to allow detailed spectral analysis. The antenna consists of two metal strips of approximately uniform width wound helically on a cone made of Lexan plastic. Since the antenna is a balanced network, a balun is employed to make the transition to a 50-ohm coaxial line. The antenna feed method is critical in maintaining a uniform impedance network. Neglecting stray transmission line effects, the probe circuit for the frequency range 100 ≤ν≤ 500 MHz is 50 ohms due to the spectrum analyzer, paralleled by 291 ohms due to balun magnetization; the combination is fed by a 144 ohm probe aperture

Space charge dosimeters for extremely low power measurements of radiation in shipping containers

Science.gov (United States)

Britton, Jr; Charles, L [Alcoa, TN; Buckner, Mark A [Oak Ridge, TN; Hanson, Gregory R [Clinton, TN; Bryan, William L [Knoxville, TN

2011-04-26

Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

Broadband Optical Access Technologies to Converge towards a Broadband Society in Europe

Science.gov (United States)

Coudreuse, Jean-Pierre; Pautonnier, Sophie; Lavillonnière, Eric; Didierjean, Sylvain; Hilt, Benoît; Kida, Toshimichi; Oshima, Kazuyoshi

This paper provides insights on the status of broadband optical access market and technologies in Europe and on the expected trends for the next generation optical access networks. The final target for most operators, cities or any other player is of course FTTH (Fibre To The Home) deployment although we can expect intermediate steps with copper or wireless technologies. Among the two candidate architectures for FTTH, PON (Passive Optical Network) is by far the most attractive and cost effective solution. We also demonstrate that Ethernet based optical access network is very adequate to all-IP networks without any incidence on the level of quality of service. Finally, we provide feedback from a FTTH pilot network in Colmar (France) based on Gigabit Ethernet PON technology. The interest of this pilot lies on the level of functionality required for broadband optical access networks but also on the development of new home network configurations.

Radiation sensors for medical, industrial and environmental applications: how to engage with schools and the general public

Science.gov (United States)

Seitz, B.; Campos Rivera, N.; Gray, R.; Powell, A.; Thomson, F.

2018-01-01

Radiation, radiation detection and radiation protection are topics in physics and its applications which generate a wide interest in the public. This interest is either generated through medical procedures, applications of nuclear energy or nuclear accidents. The technical nature of these topics usually means that they are not well covered in the normal education stream, opening many opportunities to engage with schools and the general public to showcase the latest developments and their applications. The detection of radiation is at the very heart of understanding radiation, its fascination and associated fears. The outreach group of the nuclear physics group at the University of Glasgow demonstrates a number of successful outreach activities centred around radiation detection and described in this paper, focusing on activities delivered to a variety of audiences and related to applied nuclear physics work within our group. These concentrate on the application of novel sensor technologies for nuclear decommissioning, medical imaging modalities and the monitoring of environmental radioactivity. The paper will provide some necessary background material as well as practical instructions for some of the activities developed.

Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens.

Science.gov (United States)

Orazbayev, B; Pacheco-Peña, V; Beruete, M; Navarro-Cía, M

2015-04-06

Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

Optical fibre luminescence sensor for real-time LDR brachytherapy dosimetry

Science.gov (United States)

Woulfe, P.; O'Keeffe, S.; Sullivan, F. J.

2018-02-01

An optical fibre sensor for monitoring low dose radiation is presented. The sensor is based on a scintillation material embedded within the optical fibre core, which emits visible light when exposed to low level ionising radiation. The incident level of ionising radiation can be determined by analysing the optical emission. An optical fibre sensor is developed, based on radioluminescence whereby radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 700μm of a 1mm plastic optical fibre. The sensor is designed for in-vivo monitoring of the radiation dose during radio-active seed implantation for low dose rate (LDR) brachytherapy, in prostate cancer treatment, providing radiation oncologists with real-time information of the radiation dose to the target area and/or nearby organs at risk (OARs). The radiation from the brachytherapy seeds causes emission of visible light from the scintillation material through the process of radioluminescence, which penetrates the fibre, propagating along the optical fibre for remote detection using a multi-pixel photon counter. The sensor demonstrates a high sensitivity to 0.397mCi of Iodine125, the radioactive source most commonly used in brachytherapy for treating prostate cancer.

X-ray radiation damage studies and design of a silicon pixel sensor for science at the XFEL

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jiaguo

2013-06-15

Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of Xray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations left angle 100 right angle and left angle 111 right angle produced by four vendors, CiS, Hamamatsu, Canberra and Sintef have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron-light source. Using capacitance/ conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the densities of oxide charges and interface traps at the Si-SiO{sub 2} interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the oxide-charge density, the interface-trap density and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradiation on the oxide-charge density, the interface-trap density and the surface-current density has been investigated at doses of 100 kGy and 100 MGy. It is found that both strongly depend on the gate voltage if the electric field in the oxide points from the surface of the SiO{sub 2} to the Si-SiO{sub 2} interface. To verify the long-term stability of irradiated silicon sensors, annealing studies have been performed at 60 C and 80 C on MOS capacitors and gate-controlled diodes irradiated to 5 MGy as well, and the annealing kinetics of oxide charges and surface current were determined. Moreover, the macroscopic electrical properties of segmented sensors have slao been investigated as function of dose. It is found that the defects introduced by X-rays increase the full depletion voltage, the surface leakage current and the inter-electrode capacitance of the segmented sensor. An

X-ray radiation damage studies and design of a silicon pixel sensor for science at the XFEL

International Nuclear Information System (INIS)

Zhang, Jiaguo

2013-06-01

Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of Xray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations left angle 100 right angle and left angle 111 right angle produced by four vendors, CiS, Hamamatsu, Canberra and Sintef have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron-light source. Using capacitance/ conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the densities of oxide charges and interface traps at the Si-SiO 2 interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the oxide-charge density, the interface-trap density and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradiation on the oxide-charge density, the interface-trap density and the surface-current density has been investigated at doses of 100 kGy and 100 MGy. It is found that both strongly depend on the gate voltage if the electric field in the oxide points from the surface of the SiO 2 to the Si-SiO 2 interface. To verify the long-term stability of irradiated silicon sensors, annealing studies have been performed at 60 C and 80 C on MOS capacitors and gate-controlled diodes irradiated to 5 MGy as well, and the annealing kinetics of oxide charges and surface current were determined. Moreover, the macroscopic electrical properties of segmented sensors have slao been investigated as function of dose. It is found that the defects introduced by X-rays increase the full depletion voltage, the surface leakage current and the inter-electrode capacitance of the segmented sensor. An electron

Broadband Prosthetic Interfaces: Combining Nerve Transfers and Implantable Multichannel EMG Technology to Decode Spinal Motor Neuron Activity

Directory of Open Access Journals (Sweden)

Konstantin D. Bergmeister

2017-07-01

Full Text Available Modern robotic hands/upper limbs may replace multiple degrees of freedom of extremity function. However, their intuitive use requires a high number of control signals, which current man-machine interfaces do not provide. Here, we discuss a broadband control interface that combines targeted muscle reinnervation, implantable multichannel electromyographic sensors, and advanced decoding to address the increasing capabilities of modern robotic limbs. With targeted muscle reinnervation, nerves that have lost their targets due to an amputation are surgically transferred to residual stump muscles to increase the number of intuitive prosthetic control signals. This surgery re-establishes a nerve-muscle connection that is used for sensing nerve activity with myoelectric interfaces. Moreover, the nerve transfer determines neurophysiological effects, such as muscular hyper-reinnervation and cortical reafferentation that can be exploited by the myoelectric interface. Modern implantable multichannel EMG sensors provide signals from which it is possible to disentangle the behavior of single motor neurons. Recent studies have shown that the neural drive to muscles can be decoded from these signals and thereby the user's intention can be reliably estimated. By combining these concepts in chronic implants and embedded electronics, we believe that it is in principle possible to establish a broadband man-machine interface, with specific applications in prosthesis control. This perspective illustrates this concept, based on combining advanced surgical techniques with recording hardware and processing algorithms. Here we describe the scientific evidence for this concept, current state of investigations, challenges, and alternative approaches to improve current prosthetic interfaces.

The U.S. Market For Broadband Over Powerline, 3. edition

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-15

The report provides a study of the potential market for BPL technology in the U.S. including a look at the past, present, and future state of Broadband Over Powerline (BPL) in the U.S. The Scope of the report includes the following topics: a description of the history of powerline communications (PLC) and broadband over powerline (BPL) technology; an analysis of key drivers of BPL within the electric utility and internet access industries; an overview of BPL technology and architecture; a comparison of BPL with alternative broadband access methods; an analysis of technological, regulatory, and business barriers to BPL's success; identification of the key applications and markets for BPL; a description of business models for BPL; an analysis of key market trends in broadband internet access; a review of the market development of cable modem broadband access; profiles of major U.S. BPL market participants; and, profiles of major U.S. BPL projects.

Visible light broadband perfect absorbers

Energy Technology Data Exchange (ETDEWEB)

Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O., E-mail: wxo@hit.edu.cn [School of Science, Harbin Institute of Technology, Harbin 150001 (China)

2016-03-15

The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

Broadband infrared beam splitter for spaceborne interferometric infrared sounder.

Science.gov (United States)

Yu, Tianyan; Liu, Dingquan; Qin, Yang

2014-10-01

A broadband infrared beam splitter (BS) on ZnSe substrate used for the spaceborne interferometric infrared sounder (SIIRS) is studied in the spectral range of 4.44-15 μm. Both broadband antireflection coating and broadband beam-splitter coating in this BS are designed and tested. To optimize the optical properties and the stability of the BS, suitable infrared materials were selected, and improved deposition techniques were applied. The designed structures matched experimental data well, and the properties of the BS met the application specification of SIIRS.

A Monolithic Active Pixel Sensor for ionizing radiation using a 180 nm HV-SOI process

Energy Technology Data Exchange (ETDEWEB)

Hemperek, Tomasz, E-mail: hemperek@uni-bonn.de; Kishishita, Tetsuichi; Krüger, Hans; Wermes, Norbert

2015-10-01

An improved SOI-MAPS (Silicon On Insulator Monolithic Active Pixel Sensor) for ionizing radiation based on thick-film High Voltage SOI technology (HV-SOI) has been developed. Similar to existing Fully Depleted SOI-based (FD-SOI) MAPS, a buried silicon oxide inter-dielectric (BOX) layer is used to separate the CMOS electronics from the handle wafer which is used as a depleted charge collection layer. FD-SOI MAPS suffers from radiation damage such as transistor threshold voltage shifts due to charge traps in the oxide layers and charge states created at the silicon oxide boundaries (back gate effect). The X-FAB 180-nm HV-SOI technology offers an additional isolation by deep non-depleted implant between the BOX layer and the active circuitry which mitigates this problem. Therefore we see in this technology a high potential to implement radiation-tolerant MAPS with fast charge collection property. The design and measurement results from a first prototype are presented including charge collection in neutron irradiated samples.

Broadband waveguided light sources

NARCIS (Netherlands)

Pollnau, Markus

In recent years, broadband fiber interferometers have become very popular as basic instruments used in optical low-coherence reflectometry for diagnostics of fiber and integrated optics devices or in optical coherence tomography (OCT) for imaging applications in the biomedical field. The

Policy factors affecting broadband development in Poland

DEFF Research Database (Denmark)

Henten, Anders; Windekilde, Iwona Maria

2014-01-01

of telecommunications network development in Poland than other countries in the European Union is the reason that the circumstances and also the effects of the implementation of some solutions of the EU regulation model are different in Poland than in the most developed EU countries. The aim of the paper is to examine...... and discuss broadband access development in Poland and the policy factors influencing this development as well as to examine national strategies used to stimulate service and infrastructure competition in Poland. There are, indeed, many other factors affecting broadband development such as the income level....../distribution in the country and the infrastructural point of departure. The paper, therefore, analyses the implications of the policy initiatives in light of these basic conditions and the broader context of factors influencing broadband development. In the paper, different kinds of policy initiatives are examined...

Identifying early dehydration risk with home-based sensors during radiation treatment: a feasibility study on patients with head and neck cancer.

Science.gov (United States)

Peterson, Susan K; Shinn, Eileen H; Basen-Engquist, Karen; Demark-Wahnefried, Wendy; Prokhorov, Alexander V; Baru, Chaitanya; Krueger, Ingolf H; Farcas, Emilia; Rios, Philip; Garden, Adam S; Beadle, Beth M; Lin, Kai; Yan, Yan; Martch, Stephanie L; Patrick, Kevin

2013-12-01

Systems that enable remote monitoring of patients' symptoms and other health-related outcomes may optimize cancer care outside of the clinic setting. CYCORE (CYberinfrastructure for COmparative effectiveness REsearch) is a software-based prototype for a user-friendly cyberinfrastructure supporting the comprehensive collection and analyses of data from multiple domains using a suite of home-based and mobile sensors. This study evaluated the feasibility of using CYCORE to address early at-home identification of dehydration risk in head and neck cancer patients undergoing radiation therapy. Head and neck cancer patients used home-based sensors to capture weight, blood pressure, pulse, and patient-reported outcomes for two 5-day periods during radiation therapy. Data were sent to the radiation oncologist of each head and neck cancer patient, who viewed them online via a Web-based interface. Feasibility outcomes included study completion rate, acceptability and perceived usefulness of the intervention, and adherence to the monitoring protocol. We also evaluated whether sensor data could identify dehydration-related events. Fifty patients consented to participate, and 48 (96%) completed the study. More than 90% of patients rated their ease, self-efficacy, and satisfaction regarding use of the sensor suite as extremely favorable, with minimal concerns expressed regarding data privacy issues. Patients highly valued the ability to have immediate access to objective, self-monitoring data related to personal risk for dehydration. Clinician assessments indicated a high degree of satisfaction with the ease of using the CYCORE system and the resulting ability to monitor their patients remotely. Implementing CYCORE in a clinical oncology care setting is feasible and highly acceptable to both patients and providers.

Coherent dynamics and terahertz emission in an asymmetric quantum well coupled to broadband infrared pulses

International Nuclear Information System (INIS)

Wu, B H; Cao, J C

2004-01-01

A selected intersubband transition in the asymmetric quantum well is theoretically proposed by using the superposition of two identical time delayed and phase shifted broadband pulses. Three conduction subbands in the semiconductor quantum well structure are optically coupled with the ultrafast infrared pulses. By adjusting the delay between these two pulses, the carriers at ground level can be selectively pumped to one of the upper levels, while the other upper level remains unoccupied. Thus selective transitions in the three level model can be manipulated by optical interference. At the same time, terahertz radiation will be emitted by coherent controlled charge oscillations. The phase and amplitude of THz radiation is found to be sensitive to the optical interference of the coupling pulses

Measuring Earth's Radiation Budget from the Vicinity of the Moon

Science.gov (United States)

Swartz, W. H.; Lorentz, S. R.; Erlandson, R. E.; Cahalan, R. F.; Huang, P. M.

2018-02-01

We propose to measure Earth's radiation budget (integrated total and solar-reflected shortwave) using broadband radiometers and other technology demonstrated in space. The instrument is compact, autonomous, and has modest resource requirements.

Preliminary measurements of gamma ray effects on characteristics of broad-band GaAs field-effect transistor preamplifiers

International Nuclear Information System (INIS)

Jackson, H.G.; Shimizu, T.T.; Leskovar, B.

1985-01-01

The effect of gamma radiation on electrical characteristics of cryogenically cooled broad-band low-noise microwave preamplifiers has been preliminarily evaluated. The change in the gain and noise figure of a 1-2 GHz preamplifier using GaAs microwave transistors was determined at gamma doses between 10 5 rad to 5 /times/ 10 8 rad. The gain and noise figure was measured at ambient temperatures of 300 K and 80 K. 8 refs., 2 figs

Optical broadband in-home networks for converged service delivery

NARCIS (Netherlands)

Shi, Y.

2013-01-01

Broadband access networks, and in particular fibre-to-the-home (FTTH) networks, are offering abundantly available bandwidth in the local loop with high quality of services. Under such broadband connectivity conditions, in-home networks should not represent the bottleneck for high capacity service

Semiconductor Quantum Dash Broadband Emitters: Modeling and Experiments

KAUST Repository

Khan, Mohammed Zahed Mustafa

2013-10-01

Broadband light emitters operation, which covers multiple wavelengths of the electromagnetic spectrum, has been established as an indispensable element to the human kind, continuously advancing the living standard by serving as sources in important multi-disciplinary field applications such as biomedical imaging and sensing, general lighting and internet and mobile phone connectivity. In general, most commercial broadband light sources relies on complex systems for broadband light generation which are bulky, and energy hungry. \\tRecent demonstration of ultra-broadband emission from semiconductor light sources in the form of superluminescent light emitting diodes (SLDs) has paved way in realization of broadband emitters on a completely novel platform, which offered compactness, cost effectiveness, and comparatively energy efficient, and are already serving as a key component in medical imaging systems. The low power-bandwidth product is inherent in SLDs operating in the amplified spontaneous emission regime. A quantum leap in the advancement of broadband emitters, in which high power and large bandwidth (in tens of nm) are in demand. Recently, the birth of a new class of broadband semiconductor laser diode (LDs) producing multiple wavelength light in stimulated emission regime was demonstrated. This very recent manifestation of a high power-bandwidth-product semiconductor broadband LDs relies on interband optical transitions via quantum confined dot/dash nanostructures and exploiting the natural inhomogeneity of the self-assembled growth technology. This concept is highly interesting and extending the broad spectrum of stimulated emission by novel device design forms the central focus of this dissertation. \\tIn this work, a simple rate equation numerical technique for modeling InAs/InP quantum dash laser incorporating the properties of inhomogeneous broadening effect on lasing spectra was developed and discussed, followed by a comprehensive experimental analysis

Switched Broadband Services For The Home

Science.gov (United States)

Sawyer, Don M.

1990-01-01

In considering the deployment of fiber optics to the residence, two critical questions arise: what are the leading services that could be offered to justify the required investment; and what is the nature of the business that would offer these services to the consumer ? This talk will address these two questions together with the related issue of how the "financial engine" of today's television distribution infrastructure - TV advertising - would be affected by an open access system based on fiber optics coupled with broadband switching. On the business side, the talk concludes that the potential for open ended capacity expansion, fair competition between service providers, and new interactive services inherent in an open access, switched broadband system are the critical items in differentiating it from existing video and TV distribution systems. On the question of broadband services, the talk will highlight several new opportunities together with some findings from recent market research conducted by BNR. The talk will show that there are variations on existing services plus many new services that could be offered and which have real consumer appeal. The postulated open access system discussed here is visualized as having ultimately 1,000 to 2,000 video channels available to the consumer. Although this may appear to hopelessly fragment the TV audience and destroy the current TV advertising infrastructure, the technology of open access, switched broadband will present many new advertising techniques, which have the potential to be far more effective than those available today. Some of these techniques will be described in this talk.

Broadband Wireline Provider Service: Asymmetric xDSL; BBRI_DSLasym12

Data.gov (United States)

University of Rhode Island Geospatial Extension Program — This dataset represents the availability of wireline broadband Internet access in Rhode Island via Asymmetric xDSL technology. Broadband availability is summarized...

Direct and quantitative broadband absorptance spectroscopy with multilayer cantilever probes

Science.gov (United States)

Hsu, Wei-Chun; Tong, Jonathan Kien-Kwok; Liao, Bolin; Chen, Gang

2015-04-21

A system for measuring the absorption spectrum of a sample is provided that includes a broadband light source that produces broadband light defined within a range of an absorptance spectrum. An interferometer modulates the intensity of the broadband light source for a range of modulation frequencies. A bi-layer cantilever probe arm is thermally connected to a sample arm having at most two layers of materials. The broadband light modulated by the interferometer is directed towards the sample and absorbed by the sample and converted into heat, which causes a temperature rise and bending of the bi-layer cantilever probe arm. A detector mechanism measures and records the deflection of the probe arm so as to obtain the absorptance spectrum of the sample.

Position sensitive regions in a generic radiation sensor based on single event upsets in dynamic RAMs

International Nuclear Information System (INIS)

Darambara, D.G.; Spyrou, N.M.

1997-01-01

Modern integrated circuits are highly complex systems and, as such, are susceptible to occasional failures. Semiconductor memory devices, particularly dynamic random access memories (dRAMs), are subject to random, transient single event upsets (SEUs) created by energetic ionizing radiation. These radiation-induced soft failures in the stored data of silicon based memory chips provide the foundation for a new, highly efficient, low cost generic radiation sensor. The susceptibility and the detection efficiency of a given dRAM device to SEUs is a complicated function of the circuit design and geometry, the operating conditions and the physics of the charge collection mechanisms involved. Typically, soft error rates measure the cumulative response of all sensitive regions of the memory by broad area chip exposure in ionizing radiation environments. However, this study shows that many regions of a dynamic memory are competing charge collection centres having different upset thresholds. The contribution to soft fails from discrete regions or individual circuit elements of the memory device is unambiguously separated. Hence the use of the dRAM as a position sensitive radiation detector, with high spatial resolution, is assessed and demonstrated. (orig.)

Atlantic bottlenose dolphin (Tursiops truncatus) hearing threshold for brief broadband signals.

Science.gov (United States)

Au, Whitlow W L; Lemonds, David W; Vlachos, Stephanie; Nachtigall, Paul E; Roitblat, Herbert L

2002-06-01

The hearing sensitivity of an Atlantic bottlenose dolphin (Tursiops truncatus) to both pure tones and broadband signals simulating echoes from a 7.62-cm water-filled sphere was measured. Pure tones with frequencies between 40 and 140 kHz in increments of 20 kHz were measured along with broadband thresholds using a stimulus with a center frequency of 97.3 kHz and 88.2 kHz. The pure-tone thresholds were compared with the broadband thresholds by converting the pure-tone threshold intensity to energy flux density. The results indicated that dolphins can detect broadband signals slightly better than a pure-tone signal. The broadband results suggest that an echolocating bottlenose dolphin should be able to detect a 7.62-cm diameter water-filled sphere out to a range of 178 m in a quiet environment.

Broadband and Unbundling Regulations in OECD Countries

OpenAIRE

Wallsten, Scott

2006-01-01

Broadband penetration and available speeds vary widely across OECD countries. Policymakers around the world, and especially in countries like the U.S. that lag in the rankings, are searching for policies to narrow those gaps. Relatively little empirical work tests possible reasons for these differences. In this paper I test the impacts of regulations and demographics on broadband development in a panel dataset across countries. In addition to adding to the meager empirical literature on broad...