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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • Plastic rod scintillator
  • Radiation interaction position
  • Artificial Neural Network
  • Position sensitive detector
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • University of Qom
  • Shahrood University of Technology
109 条数据
?? 中文（中国） ▾

  • Non-destructive position measurement of coasting beam using Schottky signals

    摘要： The beam position appears in the transverse Schottky signal spectra of coasting beams at revolution frequency and its harmonics. In this contribution, we utilize this signal for beam position monitoring using regular shoe-box monitors at heavy ion synchrotron GSI SIS-18. Position resolution below 1 mm at 1 kHz rate for 10 mA current was obtained. These results demonstrate the feasibility of non-destructive position monitoring of unbunched beams in synchrotrons and storage rings using capacitive pick-up data with appropriate signal processing.

    关键词： synchrotrons,beam position monitoring,coasting beams,storage rings,Schottky signals

    更新于2025-09-10 09:29:36

  • Fingerprinting electronic structure of heme iron by ab initio modeling of metal L-edge X-ray absorption spectra

    摘要： The capability of the multiconfigurational restricted active space approach to identify electronic structure from spectral fingerprints is explored by applying it to iron L-edge X-ray absorption spectroscopy (XAS) of three heme systems that represent the limiting descriptions of iron in the Fe-O2 bond, ferrous and ferric [Fe(P)(ImH)2]0/1+ (P = porphine,ImH = imidazole), and FeII(P). The level of agreement between experimental and simulated spectral shapes is calculated using the cosine similarity, which gives a quantitative and unbiased assignment. Further dimensions in fingerprinting are obtained from the L-edge branching ratio, the integrated absorption intensity, and the edge position. The results show how accurate ab initio simulations of metal L-edge XAS can complement calculations of relative energies to identify unknown species in chemical reactions.

    关键词： multiconfigurational restricted active space,branching ratio,integrated absorption intensity,iron L-edge X-ray absorption spectroscopy,electronic structure,cosine similarity,edge position,heme systems,spectral fingerprints

    更新于2025-09-10 09:29:36

  • Design and Characterization of a Scintillator-Based Position-Sensitive Detector for Muon Imaging

    摘要： This work presents the design of a position-sensitive detector that we are evaluating for cosmic-ray muon imaging. The position-sensitive detector consists of an EJ-200 plastic scintillator panel that is 32 × 32 × 2.5 cm in dimension. A quantity of 32 parallel grooves, each 2 mm wide and 4 mm deep with a pitch of 1 cm, are carved on the top and bottom sides, in perpendicular orientation, of a scintillator panel. Two wavelength shifting optical fibers are embedded in each groove for light collection and transport. The optical fibers from each channel are coupled to one pixel of a Hamamatsu H8500C multi-anode photomultiplier tube. An encoding technique using a one-dimensional resistor network was developed to reduce the number of required readout channels for position determination. The position calibration was performed with a blue light emitting diode. The detector was shown to achieve position resolution of ~1 cm (sigma).

    关键词： resistor network,muon imaging,position sensitive,wavelength shifting fiber,Plastic scintillator

    更新于2025-09-10 09:29:36

  • A novel and fast technique for evaluation of plastic rod scintillators as position sensitive gamma-ray detectors using artificial neural networks

    摘要： The problem of how to precisely estimate the radiation interaction position is an important parameter in medical and industrial imaging systems. This paper presents a new methodology for prediction of the incident position of the gamma rays based attenuation technique and multilayer perceptron (MLP) neural network system. The detection system is comprised of a gamma-ray source (60Co or 137Cs) and a plastic rod scintillator (BC400) coupled with just one PMT at one side. The experimental setup provides the required data for training and testing the network. Using this proposed method, the radiation interaction position was predicted in plastic rod scintillator with a mean absolute error less than 0.8 and 0.5 for 137Cs and 60Co sources, respectively. The mean relative error percentage was calculated less than 3.9% and 3.5%. Also, the correlation coefficient was measured 0.999 and 0.998, respectively. The results showed that the predicted interaction position using the ANN method is in good agreement with real data. The techniques and set up used in the previous position sensitive detectors were fairly complicated whereas the new set-up and proposed method are really very simple. Also, the radiation safety, cost and shielding, and electronics requirements are minimized and optimized.

    关键词： Plastic rod scintillator,Radiation interaction position,Artificial Neural Network,Position sensitive detector

    更新于2025-09-09 09:28:46

  • [IEEE 2018 IEEE 3rd Optoelectronics Global Conference (OGC) - Shenzhen, China (2018.9.4-2018.9.7)] 2018 IEEE 3rd Optoelectronics Global Conference (OGC) - Towards Autonomous Driving Technology: A Method to Enhance Visibility in Fog Based on Low-Position Road Lighting

    摘要： To see through the thick fog is an important challenge in the field of autonomous driving technology. This experiment developed a new lighting method to improve visibility under thick fog based on the principle of visual acuity in biology of vision. The experiment was conducted in a fog equipment that is 1.5 meters * 1.2 meters * 4.0 meters in volume, with an accurate ratio of 1:15 compared with realistic road. The experiment increased the visual distance under thick fog from 1.5 meters to 3.0 meters, increased by one time. The research results are of great significance to the development of autonomous driving technology.

    关键词： low-position road lighting,visibility enhancement,autonomous driving technology,foggy weather

    更新于2025-09-09 09:28:46

  • Intellijoint HIP<sup>?</sup>: a 3D mini-optical navigation tool for improving intraoperative accuracy during total hip arthroplasty

    摘要： Total hip arthroplasty is an increasingly common procedure used to address degenerative changes in the hip joint due to osteoarthritis. Although generally associated with good results, among the challenges associated with hip arthroplasty are accurate measurement of biomechanical parameters such as leg length, offset, and cup position, discrepancies of which can lead to significant long-term consequences such as pain, instability, neurological deficits, dislocation, and revision surgery, as well as patient dissatisfaction and, increasingly, litigation. Current methods of managing these parameters are limited, with manual methods such as outriggers or calipers being used to monitor leg length; however, these are susceptible to small intraoperative changes in patient position and are therefore inaccurate. Computer-assisted navigation, while offering improved accuracy, is expensive and cumbersome, in addition to adding significantly to procedural time. To address the technological gap in hip arthroplasty, a new intraoperative navigation tool (Intellijoint HIP?) has been developed. This innovative, 3D mini-optical navigation tool provides real-time, intraoperative data on leg length, offset, and cup position and allows for improved accuracy and precision in component selection and alignment. Benchtop and simulated clinical use testing have demonstrated excellent accuracy, with the navigation tool able to measure leg length and offset to within <1 mm and cup position to within <1° in both anteversion and inclination. This study describes the indications, procedural technique, and early accuracy results of the Intellijoint HIP surgical tool, which offers an accurate and easy-to-use option for hip surgeons to manage leg length, offset, and cup position intraoperatively.

    关键词： total hip arthroplasty,cup position,Intellijoint HIP,intraoperative,leg length,offset

    更新于2025-09-09 09:28:46

  • The hard X-ray Photon Single-Shot Spectrometer of SwissFEL—initial characterization

    摘要： SwissFEL requires the monitoring of the photon spectral distribution at a repetition rate of 100 Hz for machine optimization and experiment online diagnostics. The Photon Single Shot Spectrometer has been designed for the photon energy range of 4 keV to 12 keV provided by the Aramis beamline. It is capable of measuring the spectrum in a non-destructive manner, with an energy resolution of ?E/E = (2–5) × 10?5 over a bandwidth of 0.5% on a shot-to-shot basis. This article gives a detailed description about the technical challenges, structures, and considerations when building such a device, and to further enhance the performance of the spectrometer.

    关键词： Beam-line instrumentation (beam position and pro?le monitors; beam-intensity monitors; bunch length monitors),Instrumentation for FEL

    更新于2025-09-09 09:28:46

  • [IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Transfer Learning from Synthetic to Real Images Using Variational Autoencoders for Precise Position Detection

    摘要： Capturing and labeling camera images in the real world is an expensive task, whereas synthesizing labeled images in a simulation environment is easy for collecting large-scale image data. However, learning from only synthetic images may not achieve the desired performance in the real world due to a gap between synthetic and real images. We propose a method that transfers learned detection of an object position from a simulation environment to the real world. This method uses only a significantly limited dataset of real images while leveraging a large dataset of synthetic images using variational autoencoders. Additionally, the proposed method consistently performed well in different lighting conditions, in the presence of other distractor objects, and on different backgrounds. Experimental results showed that it achieved accuracy of 1.5mm to 3.5mm on average. Furthermore, we showed how the method can be used in a real-world scenario like a “pick-and-place” robotic task.

    关键词： variational autoencoder,transfer learning,position detection,deep learning,computer simulation

    更新于2025-09-09 09:28:46

  • SnSe/SiO2/Si Heterostructures for Ultrahigh-Sensitivity, Ultrafast and Broadband Optical Position Sensitive Detectors

    摘要： In this letter, optical position sensitive detectors (PSDs) based on SnSe/SiO2/Si heterostructures with an atomically abrupt interface are fabricated via the van der Waals (vdWs) growth of the large-area multilayered SnSe nanosheets on SiO2-buffered Si. The as-fabricated SnSe/SiO2/Si PSD device has a broadband photoresponse from visable to near-infrared light, especially showing an extremely high sensitivity up to 687.5 mV/mm under a relatively low laser power of 1.0 mW and short response/relaxation time of ~0.9/17.3 μs. The unique characteristics from the SnSe/Si vdWs interface are proposed to be the key factors to contribute to the excellent performance of the fabricated PSDs.

    关键词： Si,SnSe,heterostructure,Position sensitive detectors,van der Waals growth

    更新于2025-09-09 09:28:46

  • Changes in the Blood Flow of the Optic Nerve Head Induced by Different Concentrations of Epinephrine in Intravitreal Infusion During Vitreous Surgery

    摘要： PURPOSE. We investigated whether intravitreal infusion solution containing epinephrine affects optic nerve head (ONH) blood ?ow during vitreous surgeries. METHODS. The subjects were 22 patients with epimacular membrane or idiopathic macular hole. During vitreous surgery, ONH blood ?ow was examined before and 10 minutes after intravitreal infusion of solution containing epinephrine, via a laser speckle ?owgraphy (LSFG) technique modi?ed for acquiring measurements in a supine position. Epinephrine concentration was set at 1.0 mg/500 mL (1:500,000) or 0.5 mg/500 mL (1:1,000,000), with each concentration assigned to 11 consecutive patients. Relative pupil diameter, IOP, blood pressure, and pulse rate also were measured. RESULTS. A signi?cant reduction in blood ?ow throughout the ONH was induced by intravitreal infusion of epinephrine at 1:500,000, but not at 1:1,000,000. Blood ?ow in ONH tissue was diminished at both concentrations, while that in vessels of the ONH was not altered signi?cantly by either concentration. Both epinephrine concentrations induced signi?cant pupillary dilatation, but no signi?cant changes in IOP, blood pressure, or pulse rate. CONCLUSIONS. This study suggests that epinephrine, used in combination with intravitreal infusion solution, may decrease ONH blood ?ow during vitreous surgeries, as indicated by measurements obtained via a modi?ed LSFG technique. Attention must be paid to the effects of intravitreal infusion of epinephrine on ocular circulation, particularly ONH blood ?ow.

    关键词： laser speckle ?owgraphy,optic nerve head,epinephrine,supine position,blood ?ow,vitreous surgery

    更新于2025-09-09 09:28:46