Unique Detectors Research Articles

Basic characteristics of synthetic-diamond scintillator

To extend the use of diamond detectors to particle detail analysis and the development of radiation monitoring applications, we conducted a study on synthetic-diamond scintillators, which have so far not been sufficiently evaluated. To understand the basic characteristics of scintillators, we measured the luminescence characteristics of two types of commercially available synthetic diamonds manufactured via high-pressure high-temperature (HPHT) and chemical vapor deposition (CVD) methods. The color center of each diamond was identified by measuring the radio-luminescence spectrum under X-ray excitation, and the scintillation light waveform was measured by irradiating α-rays and β-rays. The light yield of the HPHT diamond with a nitrogen concentration less than 200 ppm had a higher emission than that of the CVD diamond with a nitrogen concentration of less than 1 ppm; the light yield for the former was estimated to be (5.5 ± 0.5) × 104 ph/MeV. Because of the significant light yield and physical properties of diamonds, unique particle detectors can be achieved.

Object Sub-Categorization and Common Framework<br /> Method using Iterative AdaBoost for Rapid Detection of Multiple Objects

Object detection and tracking in real time has numerous applications and benefits in various fields like survey, crime detection etc. The idea of gaining useful information from real time scenes on the roads is called as Traffic Scene Perception (TSP). TSP actually consists of three subtasks namely, detecting things of interest, recognizing the discovered objects and tracking of the moving objects. Normally the results obtained could be of value in object recognition and tracking, however the detection of a particular object of interest is of higher value in any real time scenario. The prevalent systems focus on developing unique detectors for each of the above-mentioned subtasks and they work upon utilizing different features. This obviously is time consuming and involves multiple redundant operations. Hence in this paper a common framework using the enhanced AdaBoost algorithm is proposed which will examine all dense characteristics only once thereby increasing the detection speed substantially. An object sub-categorization strategy is proposed to capture the intra-class variance of objects in order to boost generalisation performance even more. We use three detection applications to demonstrate the efficiency of the proposed framework: traffic sign detection, car detection, and bike detection. On numerous benchmark data sets, the proposed framework delivers competitive performance using state-of-the-art techniques.

Asymmetric visual representation of sex from facial appearance

We efficiently infer others’ traits from their faces, and these inferences powerfully shape our social behaviour. Here, we investigated how sex is represented in facial appearance. Based on previous findings from sex-judgment tasks, we hypothesized that the perceptual encoding of sex is not balanced but rather polarized: for the processes that generate a sex percept, the default output is “male,” and the representation of female faces extends that of the male, engaging activity over unique detectors that are not activated by male faces. We tested this hypothesis with the logic of Treisman’s studies of visual search asymmetries, predicting that observers should more readily detect the presence of female faces amongst male distractors than vice versa. Across three experiments (N = 32 each), each using different face stimuli, we confirmed this prediction in response time and sensitivity measures. We apply GIST analyses to the face stimuli to exclude that the search asymmetry is explained by differences in image homogeneity. These findings demonstrate a property of the coding that links facial appearance with a significant social trait: the female face is coded as an extension of a male default. We offer a mechanistic description of perceptual detectors to account for our findings and posit that the origins of this polarized coding scheme are an outcome of biased early developmental experience.

Skewness-based characterization of silicon photomultipliers

Characterization of SiPMs is an objective of high importance in almost any research, development, and application of these unique photon detectors. Two decades of characterization method developments resulted in a comprehensive and elegant methodology based on a precisely resolved number of fired SiPM cells or the SiPM spectrum. Spectrum fitting procedures are very sensitive to a proper selection of many initial guess values including parameters of minor importance and happen to be unreliable. Moreover, conventional methods are useless for degraded or unresolved SiPM spectra. This challenge was anticipated for SiPM-based detectors of high-luminosity particle calorimeters where a severe radiation degradation of the SiPMs would co-exist with their acceptable performance. To address it, one can measure a mean and variance of SiPM charge responses relying on a priori known Excess Noise Factor of the SiPM but its stability during SiPM degradation is uncertain. This study proposes and evaluates a new approach for the SiPM characterization based on the first three statistical moments (mean, variance, and skewness) of its charge response including skewness. It assumes the Generalized Poisson distribution of the number of fired cells and provides simple closed-form analytical expressions for the parameter estimation. It allows determining a gain, a number of detected photons, and a probability of correlated events directly from raw data. The skewness-based characterization is anticipated to be especially useful for mass testing and continuous monitoring of SiPMs in large-scale experiments due to its simplicity and robustness. Initial evaluations of the method show promising results.

HPLC/Fluorescence-Diode Array Detection for Rapid and Reliable Determination of Illegal Synthetic Drugs in Male Sexual Herbal and Honey Remedies: Comparative Study with UFLC-MS.

Nutraceuticals (NTCs), as honey and tablets with herbal extract are subjected to adulteration. For NTCs claimed to enhance sexual performance, synthetic drugs (sildenafil, tadalafil, avanafil, vardenafil, and dapoxetine) are common adulterants, so they were selected to be simultaneously analyzed in the current study. Natural aphrodisiacs (icariin and yohimbine) are claimed to be present in many fake NTCs, so they were also included in the study. In order to achieve the target of the current study, three liquid chromatographic methods with different unique detectors were developed and validated. High performance liquid chromatography (HPLC) with fluorescence detection enables rapid and reliable determination of natively fluorescent yohimbine, tadalafil vardenafil, and dapoxetine and it is the first report to analyze these compounds as adulterants in counterfeit NTC. Although the diode-array detector (DAD) enables the analysis of the seven adulterants, the fluorescence detector (FLD) shows better sensitivity and selectivity with lower LOQs and LODs. On the other hand, ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) offers the advantages of peak identity confirmation, and it is of comparable sensitivity and selectivity to HPLC-FLD. One or more of these synthetic drugs were found in the analyzed NTCs while natural aphrodisiacs were absent. Aphrodisiac nutraceuticals, NTCs, were analyzed for adulterants: five aphrodisiac synthetic drugs (adulterants) and two natural claimed aphrodisiacs. UFLC-MS and HPLC-DAD/FLD were compared for illicit NTCs analysis; all NTCs show the presence of synthetic aphrodisiacs and the absence of natural ones.

A New Popularity Prediction Model for Detection of Trending Topics based on Support Vector Machine over Online Social Networking

Social network is the most reliable platform to share data. It produces a huge number of subjects each day. Online media is critical for business associations to learn the popularity of these themes as fast as could be expected. This paper is centered around the investigation of five distinctive existing trending detection methods, such as The Prediction Model based on SVM, Multi Linear Model, Dual Attention Model, Self Attention based Model, Trust Prediction Model, etc. But a few upsides and downsides are seen in these methods. These methodologies have been analyzed to address the limits of the trending topic popularity prediction such as video lifetime, burst and evolution pattern, execution, error rate, time, overhead, throughput, delay, limit, and so on. In this paper, “Rapid Miner” tool is used to implement the proposed method. The correlation matrix is used for pattern detection, then clustering is performed over the output of the correlation matrix and obtains the data in cluster format i.e. in similar sequence, and again random clustering technique is performed over previous K-means clustering result, in which, it simply divides topic information into time slices which are utilized as a unit, and such units are provides to the two unique detectors, for example, lifetime and bursty detector. At last, SVM classification predicts the outcomes in the type of a "Trending Topic" and a "Non-Trending Topic". The proposed strategy is “Detection of the Trending Topic” which dependent on SVM. The proposed method recognizes the lifetime of recordings, bustiness of recordings, and evolution pattern. It decreases the mistake rate, time, overhead, delay, and enhances the precision, execution, use of mistake rate as a measurement, throughput, ability to improve the trending subject identification rate, etc. This proposed strategy concentrates on a trending subject and fake data over OSN.

Nanowire-Enabled Bioelectronics.

Bioelectronics explores the use of electronic devices for applications in signal transduction at their interfaces with biological systems. The miniaturization of the bioelectronic systems has enabled seamless integration at these interfaces and is providing new scientific and technological opportunities. In particular, nanowire-based devices can yield smaller sized and unique geometry detectors that are difficult to access with standard techniques, and thereby can provide advantages in sensitivity with reduced invasiveness. In this review, we focus on nanowire-enabled bioelectronics. First, we provide an overview of synthetic studies for designed growth of semiconductor nanowires of which structure and composition are controlled to enable key elements for bioelectronic devices. Second, we review nanowire field-effect transistor sensors for highly sensitive detection of biomolecules, their applications in diagnosis and drug discovery, and methods for sensitivity enhancement. We then turn to recent progress in nanowire-enabled studies of electrogenic cells, including cardiomyocytes and neurons. Representative advances in electrical recording using nanowire electronic devices for single cell measurements, cell network mapping, and three-dimensional recordings of synthetic and natural tissues, and in vivo brain mapping are highlighted. Finally, we overview the key challenges and opportunities of nanowires for fundamental research and translational applications.

Statistical Benchmarking of Scalable Photonic Quantum Systems.

Targeting at the realization of scalable photonic quantum technologies, the generation of many photons, their propagation in large optical networks, and a subsequent detection and analysis of sophisticated quantum correlations are essential for the understanding of macroscopic quantum systems. In this experimental contribution, we explore the joint operation of all mentioned ingredients. We benchmark our time-multiplexing framework that includes a high-performance source of multiphoton states and a large multiplexing network, together with unique detectors with high photon-number resolution, readily available for distributing quantum light and measuring complex quantum correlations. Using an adaptive approach that employs flexible time bins, rather than static ones, we successfully verify high-order nonclassical correlations of many photons distributed over many modes. By exploiting the symmetry of our system and using powerful analysis tools, we can analyze correlations that would be inaccessible by classical means otherwise. In particular, we produce on the order of ten photons and distribute them over 64 modes. Nonclassicality is verified with correlation functions up to the 128th order and statistical significances of up to 20 standard deviations.

On-Orbit Relative Radiometric Calibration of the Night-Time Sensor of the LuoJia1-01 Satellite.

The LuoJia1-01 satellite can acquire high-resolution, high-sensitivity nighttime light data for night remote sensing applications. LuoJia1-01 is equipped with a 4-megapixel CMOS sensor composed of 2048 × 2048 unique detectors that record weak nighttime light on Earth. Owing to minute variations in manufacturing and temporal degradation, each detector’s behavior varies when exposed to uniform radiance, resulting in noticeable detector-level errors in the acquired imagery. Radiometric calibration helps to eliminate these detector-level errors. For the nighttime sensor of LuoJia1-01, it is difficult to directly use the nighttime light data to calibrate the detector-level errors, because at night there is no large-area uniform light source. This paper reports an on-orbit radiometric calibration method that uses daytime data to estimate the relative calibration coefficients for each detector in the LuoJia1-01 nighttime sensor, and uses the calibrated data to correct nighttime data. The image sensor has a high dynamic range (HDR) mode, which is optimized for day/night imaging applications. An HDR image can be constructed using low- and high-gain HDR images captured in HDR mode. Hence, a day-to-night radiometric reference transfer model, which uses daytime uniform calibration to calibrate the detector non-uniformity of the nighttime sensor, is herein built for LuoJia1-01. Owing to the lack of calibration equipment on-board LuoJia1-01, the dark current of the nighttime sensor is calibrated by collecting no-light desert images at new moon. The results show that in HDR mode (1) the root mean square of mean for each detector in low-gain (high-gain) images is better than 0.04 (0.07) in digital number (DN) after dark current correction; (2) the DN relationship between low- and high-gain images conforms to the quadratic polynomial mode; (3) streaking metrics are better than 0.2% after relative calibration; and (4) the nighttime sensor has the same relative correction parameters at different exposure times for the same gain parameters.

DEATH-STAR: Silicon and Photovoltaic Fission Fragment Detector Arrays for Light-Ion Induced Fission Correlation Studies

The Direct Excitation Angular Tracking pHotovoltaic-Silicon Telescope ARray (DEATH-STAR) combines a series of 12 silicon detectors in a ΔE−E configuration for charged particle identification with a large-area array of 56 photovoltaic (solar) cells for detection of fission fragments. The combination of many scattering angles and fission fragment detectors allows for an angular-resolved tool to study reaction cross sections using the surrogate method, anisotropic fission distributions, and angular momentum transfers through stripping, transfer, inelastic scattering, and other direct nuclear reactions. The unique photovoltaic detectors efficiently detect fission fragments while being insensitive to light ions and have a timing resolution of 15.63±0.37ns. Alpha particles are detected with a resolution of 35.5keV 1σ at 7.9MeV. Measured fission fragment angular distributions are also presented.

Summary of recent BNCT Polish programme and future plans

In this work we present Polish achievements on the ground of BNCT research. Starting from preliminary built therapeutic stand at MARIA reactor going through designing of unique detectors for in-phantom and in-beam measurements for mixed radiation fields and finally coming to boron carriers synthesizing and examination in cellular and animal models. Now it is planned to restart research on boron compounds in specially designed BIMA line, to set up epithermal neutron irradiation facility for BNCT research and education and to improve recombination detectors for neutron beams characterisation.

Radiometric Non-Uniformity Characterization and Correction of Landsat 8 OLI Using Earth Imagery-Based Techniques

Landsat 8 is the first satellite in the Landsat mission to acquire spectral imagery of the Earth using pushbroom sensor instruments. As a result, there are almost 70,000 unique detectors on the Operational Land Imager (OLI) alone to monitor. Due to minute variations in manufacturing and temporal degradation, every detector will exhibit a different behavior when exposed to uniform radiance, causing a noticeable striping artifact in collected imagery. Solar collects using the OLI’s on-board solar diffuser panels are the primary method of characterizing detector level non-uniformity. This paper reports on an approach for using a side-slither maneuver to estimate relative detector gains within each individual focal plane module (FPM) in the OLI. A method to characterize cirrus band detector-level non-uniformity using deep convective clouds (DCCs) is also presented. These approaches are discussed, and then, correction results are compared with the diffuser-based method. Detector relative gain stability is assessed using the side-slither technique. Side-slither relative gains were found to correct streaking in test imagery with quality comparable to diffuser-based gains (within 0.005% for VNIR/PAN; 0.01% for SWIR) and identified a 0.5% temporal drift over a year. The DCC technique provided relative gains that visually decreased striping over the operational calibration in many images.

Space Solar Patrol data and changes in weather and climate, including global warming**This article was originally submitted for inclusion with the papers from the 9th International Symposium on Measurement Science and Intelligent Instruments (ISMTII-2009), published in the May 2010 issue.

In this paper, the results obtained during the execution of several ISTC projects are presented. The general aim of these projects has been the study of global changes in the environment, connected with solar activity. A brief description of the optical apparatus of the Space Solar Patrol (SSP) developed and built in the framework of the ISTC projects 385, 385.2, 1523 and 2500 is given. The SSP is intended for permanent monitoring of spectra and absolute fluxes of soft x-ray and extreme ultraviolet (x-ray/EUV) radiation from the full disk of the Sun which ionizes the upper atmosphere of the Earth. Permanent solar monitoring in the main part of the ionizing radiation spectra 0.8–115 (119) nm does not exist. The apparatus of the SSP was developed in the years 1996–2005 with multiyear experience of developing such apparatus in S I Vavilov State Optical Institute. The basis of this apparatus is the use of unique detectors of ionizing radiation—open secondary electron multipliers, which are ‘solar blind’ to near UV, visible and IR radiation from the Sun, and new methodology of these solar spectroradiometric absolute measurements. The prospects are discussed of using the SSP data for the investigation and forecast of the influence of solar variability on the weather and climate including global warming and also on the biosphere including human beings (proposal 3878).

Solubilization of carbon nanotubes by cellulose xanthate toward the fabrication of enhanced amperometric detectors

Negatively charged cellulose xanthate was employed as a solubilizing agent of carbon nanotubes to prepare a highly stable aqueous suspension. The obtained mixture was subsequently allowed to coagulate on disc electrodes in sulfuric acid solution to prepare carbon nanotube–cellulose composite modified electrodes as sensitive amperometric detectors of capillary electrophoresis. The structure and morphology of the prepared carbon nanotube–cellulose composite were investigated by fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy techniques. The results indicated that carbon nanotubes were well dispersed and embedded throughout the regenerated cellulose to form an interconnected carbon nanotube network on the base electrodes. The performance of the unique carbon nanotube-based detectors was demonstrated by separating and detecting four phenolic compounds in combination with capillary electrophoresis. The novel carbon nanotube-based detectors offered significantly lower operating potentials, substantially enhanced signal-to-noise characteristics, and lower expense of operation.

Reactor neutrino monitoring

Nuclear reactors are the most intense man-controlled sources of antineutrinos and as such have hosted number of key physics experiments, from the antineutrino discovery to modern oscillation measurements. At the present time, both detection technology and understanding of fundamental physics are mature enough to think about antineutrinos as a new tool for reactor monitoring. We describe below how antineutrinos can provide online information on reactor operation and amount of plutonium accumulated in the core. Reactors are the only sources of plutonium on earth and this element can be chemically separated from the rest of the nuclear fuel and diverted into nuclear weapons. We present in the next sections the unique features antineutrino detectors could provide to safeguards agencies such as IAEA. We review the worldwide efforts to develop small ( 1 m 3 scale) antineutrino detectors dedicated to automated and non-intrusive reactor monitoring.

On‐board processing for communication satellites: Technologies and implementations

AbstractThis paper presents technologies which are key candidates for advanced on‐board processing for future communication satellites. Satellite switching centres for microwave and baseband signals, on‐board coherent modems for 120Mb/s burst‐mode TDMA systems and their technologies are discussed. A brief description of on‐board demultiplexing and demodulation of low bit rate carriers is offered and study results on investigation of on‐board unique word detectors and large buffers are presented.

Pockels readout optical modulator: An x-ray imaging detector that maintains good efficiency over a broad energy range

We present measurements of the performance of a Pockels readout optical modulator (PROM) x-ray imaging detector using a 30-kV constant potential bremsstrahlung source. A nickel step wedge was used to measure the spatial resolution and noise of the PROM image. PROMs are unique high-efficiency x-ray detectors that image with good spatial resolution over a wide range of x-ray energy. The PROM is constructed from an optically transparent, active crystal that is sensitive to x-ray dose. This unique construction allows the use of a thick crystal to increase efficiency for x-ray detection while avoiding the spatial resolution degradation that usually accompanies thick detectors.

A New Approach to Testing High-Voltage Deflection Tubes

Techniques which are generally applicable to high-voltage deflection tubes are discussed in this paper, with specific application to television horizontal-deflection amplifiers. In an entirely new approach to testing horizontal-deflection amplifiers, the tubes are tested in circuits that closely simulate actual operating conditions. Six separate tests have been replaced by a single test. Carefully controlled test conditions and the development of several unique detectors for these tests have resulted in repeatable and reproducible results. Although the circuits have become more complex as a result of simplifying the testing procedures, cost of over-all testing has been reduced and product quality has been improved.