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Silicon detector

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https://www.readbyqxmd.com/read/28211032/depth-of-interaction-determination-in-monolithic-scintillator-with-double-side-sipm-readout
#1
Matteo Morrocchi, Giovanni Ambrosi, Maria Giuseppina Bisogni, Filippo Bosi, Marco Boretto, Piergiorgio Cerello, Maria Ionica, Ben Liu, Francesco Pennazio, Maria Antonietta Piliero, Giovanni Pirrone, Vasile Postolache, Richard Wheadon, Alberto Del Guerra
BACKGROUND: Monolithic scintillators read out by arrays of photodetectors represent a promising solution to obtain high spatial resolution and the depth of interaction (DOI) of the annihilation photon. We have recently investigated a detector geometry composed of a monolithic scintillator readout on two sides by silicon photomultiplier (SiPM) arrays, and we have proposed two parameters for the DOI determination: the difference in the number of triggered SiPMs on the two sides of the detector and the difference in the maximum collected signal on a single SiPM on each side...
December 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/28198881/mode-evolution-based-coupler-for-high-saturation-power-ge-on-si-photodetectors
#2
Matthew J Byrd, Erman Timurdogan, Zhan Su, Christopher V Poulton, Nicholas M Fahrenkopf, Gerald Leake, Douglas D Coolbaugh, Michael R Watts
We propose a mode-evolution-based coupler for high saturation power germanium-on-silicon photodetectors. This coupler uniformly illuminates the intrinsic germanium region of the detector, decreasing saturation effects, such as carrier screening, observed at high input powers. We demonstrate 70% more photocurrent generation (9.1-15.5 mA) and more than 40 times higher opto-electrical bandwidth (0.7-31 GHz) than conventional butt-coupled detectors under high-power illumination. The high-power and high-speed performance of the device, combined with the compactness of the coupling method, will enable new applications for integrated silicon photonics systems...
February 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28192287/improved-image-quality-using-monolithic-scintillator-detectors-with-dual-sided-readout-in-a-whole-body-tof-pet-ring-a-simulation-study
#3
Valerio Tabacchini, Suleman Surti, Giacomo Borghi, Joel S Karp, Dennis R Schaart
We have recently built and characterized the performance of a monolithic scintillator detector based on a 32 mm  ×  32 mm  ×  22 mm LYSO:Ce crystal read out by digital silicon photomultiplier (dSiPM) arrays coupled to the crystal front and back surfaces in a dual-sided readout (DSR) configuration. The detector spatial resolution appeared to be markedly better than that of a detector consisting of the same crystal with conventional back-sided readout (BSR). Here, we aim to evaluate the influence of this difference in the detector spatial response on the quality of reconstructed images, so as to quantify the potential benefit of the DSR approach for high-resolution, whole-body time-of-flight (TOF) positron emission tomography (PET) applications...
February 13, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28181671/quantitative-x-ray-microanalysis-of-model-biological-samples-in-the-sem-using-remote-standards-and-the-xpp-analytical-model
#4
Alan T Marshall
It is shown that accurate x-ray microanalysis of frozen-hydrated and dry organic compounds, such as model biological samples, is possible with a silicon drift detector in combination with XPP (exponential model of Pouchou and Pichoir matrix correction) software using 'remote standards'. This type of analysis is also referred to as 'standardless analysis'. Analyses from selected areas or elemental images (maps) were identical. Improvements in x-ray microanalytical hardware and software, together with developments in cryotechniques, have made the quantitative analysis of cryoplaned frozen-hydrated biological samples in the scanning electron microscope a much simpler procedure...
February 9, 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28181489/chip-based-quantum-key-distribution
#5
P Sibson, C Erven, M Godfrey, S Miki, T Yamashita, M Fujiwara, M Sasaki, H Terai, M G Tanner, C M Natarajan, R H Hadfield, J L O'Brien, M G Thompson
Improvement in secure transmission of information is an urgent need for governments, corporations and individuals. Quantum key distribution (QKD) promises security based on the laws of physics and has rapidly grown from proof-of-concept to robust demonstrations and deployment of commercial systems. Despite these advances, QKD has not been widely adopted, and large-scale deployment will likely require chip-based devices for improved performance, miniaturization and enhanced functionality. Here we report low error rate, GHz clocked QKD operation of an indium phosphide transmitter chip and a silicon oxynitride receiver chip-monolithically integrated devices using components and manufacturing processes from the telecommunications industry...
February 9, 2017: Nature Communications
https://www.readbyqxmd.com/read/28180132/study-of-material-properties-important-for-an-optical-property-modulation-based-radiation-detection-method-for-positron-emission-tomography
#6
Li Tao, Henry M Daghighian, Craig S Levin
We compare the performance of two detector materials, cadmium telluride (CdTe) and bismuth silicon oxide (BSO), for optical property modulation-based radiation detection method for positron emission tomography (PET), which is a potential new direction to dramatically improve the annihilation photon pair coincidence time resolution. We have shown that the induced current flow in the detector crystal resulting from ionizing radiation determines the strength of optical modulation signal. A larger resistivity is favorable for reducing the dark current (noise) in the detector crystal, and thus the higher resistivity BSO crystal has a lower (50% lower on average) noise level than CdTe...
January 2017: Journal of Medical Imaging
https://www.readbyqxmd.com/read/28178236/photovoltage-field-effect-transistors
#7
Valerio Adinolfi, Edward H Sargent
The detection of infrared radiation enables night vision, health monitoring, optical communications and three-dimensional object recognition. Silicon is widely used in modern electronics, but its electronic bandgap prevents the detection of light at wavelengths longer than about 1,100 nanometres. It is therefore of interest to extend the performance of silicon photodetectors into the infrared spectrum, beyond the bandgap of silicon. Here we demonstrate a photovoltage field-effect transistor that uses silicon for charge transport, but is also sensitive to infrared light owing to the use of a quantum dot light absorber...
February 8, 2017: Nature
https://www.readbyqxmd.com/read/28162123/dictionary-indexing-of-electron-channeling-patterns
#8
Saransh Singh, Marc De Graef
The dictionary-based approach to the indexing of diffraction patterns is applied to electron channeling patterns (ECPs). The main ingredients of the dictionary method are introduced, including the generalized forward projector (GFP), the relevant detector model, and a scheme to uniformly sample orientation space using the "cubochoric" representation. The GFP is used to compute an ECP "master" pattern. Derivative free optimization algorithms, including the Nelder-Mead simplex and the bound optimization by quadratic approximation are used to determine the correct detector parameters and to refine the orientation obtained from the dictionary approach...
February 6, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28159242/comparison-of-different-ccd-detectors-and-chemometrics-for-predicting-total-anthocyanin-content-and-antioxidant-activity-of-mulberry-fruit-using-visible-and-near-infrared-hyperspectral-imaging-technique
#9
Lingxia Huang, Yibin Zhou, Liuwei Meng, Di Wu, Yong He
This study investigated the potential of using hyperspectral imaging technique in tandem with chemometrics for rapid and invasive predicting total anthocyanin content and antioxidant activity of mulberry fruit. Two calibration methods of partial least square regression and least-squares support vector machines and three wavelength selection algorithms of successive projections algorithm, uninformation variable elimination, and competitive adaptive reweighted sampling were applied. The best prediction models for the analysis of total anthocyanin content and antioxidant activity had Rval(2) of 0...
June 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28156098/accurate-and-precise-determination-of-mechanical-properties-of-silicon-nitride-beam-nanoelectromechanical-devices
#10
Hakseong Kim, Dong Hoon Shin, Kirstie McAllister, Miri Seo, Sangik Lee, Il-Suk Kang, Bae Ho Park, Eleanor E B Campbell, Sang Wook Lee
Accurate and precise determination of mechanical properties of nanoscale materials is mandatory since device performances of nanoelectromechanical systems (NEMS) are closely related to the flexural properties of the materials. In this study, the intrinsic mechanical properties of highly stressed silicon nitride (SiN) beams of varying lengths are investigated using two different techniques: Dynamic flexural measurement using optical interferometry and quasi-static flexural measurement using atomic force microscopy...
February 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28152195/a-2d-silicon-detector-array-for-quality-assurance-in-small-field-dosimetry-duo
#11
Khalsa Al Shukaili, Marco Petasecca, Matthew Newall, Anthony Espinoza, Vladimir L Perevertaylo, Stéphanie Corde, Michael Lerch, Anatoly B Rosenfeld
PURPOSE: Nowadays, there are many different applications that use small fields in radiotherapy treatments. The dosimetry of small radiation fields is not trivial due to the problems associated with lateral disequilibrium and source occlusion and requires reliable quality assurance (QA). Ideally such a QA tool should provide high spatial resolution, minimal beam perturbation and real time fast measurements. Many different types of silicon diode arrays are used for QA in radiotherapy; however, their application in small filed dosimetry is limited, in part, due to a lack of spatial resolution...
December 10, 2016: Medical Physics
https://www.readbyqxmd.com/read/28151733/correction-factors-to-convert-microdosimetry-measurements-in-silicon-to-tissue-in-12-c-ion-therapy
#12
David Bolst, Susanna Guatelli, Linh T Tran, Lachlan Chartier, Michael L F Lerch, Naruhiro Matsufuji, Anatoly B Rosenfeld
Silicon microdosimetry is a promising technology for heavy ion therapy (HIT) quality assurance, because of its sub-mm spatial resolution and capability to determine radiation effects at a cellular level in a mixed radiation field. A drawback of silicon is not being tissue-equivalent, thus the need to convert the detector response obtained in silicon to tissue. This paper presents a method for converting silicon microdosimetric spectra to tissue for a therapeutic (12)C beam, based on Monte Carlo simulations...
February 2, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28147700/photon-counting-phosphorescence-lifetime-imaging-with-timepixcam
#13
Liisa M Hirvonen, Merlin Fisher-Levine, Klaus Suhling, Andrei Nomerotski
TimepixCam is a novel fast optical imager based on an optimized silicon pixel sensor with a thin entrance window and read out by a Timepix Application Specific Integrated Circuit. The 256 × 256 pixel sensor has a time resolution of 15 ns at a sustained frame rate of 10 Hz. We used this sensor in combination with an image intensifier for wide-field time-correlated single photon counting imaging. We have characterised the photon detection capabilities of this detector system and employed it on a wide-field epifluorescence microscope to map phosphorescence decays of various iridium complexes with lifetimes of about 1 μs in 200 μm diameter polystyrene beads...
January 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28146088/a-ring-artifact-correction-method-validation-by-micro-ct-imaging-with-flat-panel-detectors-and-a-2d-photon-counting-detector
#14
Mohamed Elsayed Eldib, Mohamed Hegazy, Yang Ji Mun, Myung Hye Cho, Min Hyoung Cho, Soo Yeol Lee
We introduce an efficient ring artifact correction method for a cone-beam computed tomography (CT). In the first step, we correct the defective pixels whose values are close to zero or saturated in the projection domain. In the second step, we compute the mean value at each detector element along the view angle in the sinogram to obtain the one-dimensional (1D) mean vector, and we then compute the 1D correction vector by taking inverse of the mean vector. We multiply the correction vector with the sinogram row by row over all view angles...
January 30, 2017: Sensors
https://www.readbyqxmd.com/read/28134130/chemically-tuned-linear-energy-transfer-dependent-quenching-in-a-deformable-radiochromic-3d-dosimeter
#15
Ellen Marie Høye, Peter S Skyt, Peter Balling, Ludvig P Muren, Vicki T Taasti, Jan Swakoń, Gabriela Mierzwińska, Marzena Rydygier, Niels Bassler, Jørgen B B Petersen
Most solid-state detectors, including 3D dosimeters, show lower signal in the Bragg peak than expected, a process termed quenching. The purpose of this study was to investigate how variation in chemical composition of a recently developed radiochromic, silicone-based 3D dosimeter influences the observed quenching in proton beams. The dependency of dose response on linear energy transfer, as calculated through Monte Carlo simulations of the dosimeter, was investigated in 60 MeV proton beams. We found that the amount of quenching varied with the chemical composition: peak-to-plateau ratios (1 cm into the plateau) ranged from 2...
February 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28124558/simple-nanoimprinted-polymer-nanostructures-for-uncooled-thermal-detection-by-direct-surface-plasmon-resonance-imaging
#16
Brandon Hong, Felipe Vallini, Cheng-Yi Fang, Amr Ghalib Alasaad, Yeshaiahu Fainman
We experimentally demonstrate the uncooled detection of long wavelength-infrared (LWIR) radiation by thermal surface plasmon sensing, using an all optical read-out format. Thermal infrared radiation absorbed by an IR-sensitive material with high thermo-optic coefficient coated on a metal grating creates a refractive index change detectable by the shift of the supported surface plasmon resonance (SPR) measured optically in the visible spectrum. The interface localization of SPR modes and optical readout allow for submicron thin film transducers and eliminate complex readout integrated circuits, respectively, reducing form factor, leveraging robust visible detectors and enabling low-cost imaging cameras...
January 26, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28113987/optical-characterization-of-tissue-phantoms-using-a-silicon-integrated-fdnirs-system-on-chip
#17
Chirag C Sthalekar, Yun Miao, Valencia Joyner Koomson
An interface circuit with signal processing and digitizing circuits for a high frequency, large area avalanche photodiode (APD) has been integrated in a 130 nm BiCMOS chip. The system enables the absolute oximetry of tissue using frequency domain Near Infrared Spectroscopy (fdNIRS). The system measures the light absorbed and scattered by the tissue by measuring the reduction in the amplitude of signal and phase shift introduced between the light source and detector which are placed a finite distance away from each other...
September 22, 2016: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/28113455/design-features-and-mutual-compatibility-studies-of-the-time-of-flight-pet-capable-ge-signa-pet-mr-system
#18
Craig S Levin, Sri Harsha Maramraju, Mohammad Mehdi Khalighi, Timothy W Deller, Gaspar Delso, Floris Jansen
A recent entry into the rapidly evolving field of integrated PET/MR scanners is presented in this paper: a whole body hybrid PET/MR system (SIGNA PET/MR, GE Healthcare) capable of simultaneous acquisition of both time-of-flight (TOF) PET and high resolution MR data. The PET ring was integrated into an existing 3T MR system resulting in a (patient) bore opening of 60 cm diameter, with a 25 cm axial FOV. The PET ring is placed between the shielded RF body coil and the gradient coils. The PET detectors are based on silicon photomultipliers coupled to lutetium based scintillators...
March 9, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28111484/a-nuclear-geochemical-analysis-system-for-boron-quantification-using-a-focused-ion-beam
#19
E J Charlotta Nilsson, Per Kristiansson, Linus Ros, Nathaly De La Rosa, Mikael Elfman, Ulf Hålenius, Jan Pallon, Henrik Skogby
Ion beam analysis has for decades been used as a tool for geochemical analysis of trace elements using both X-rays (particle induced X-ray emission) and nuclear reaction analysis. With the geoanalytical setup at the Lund Ion Beam Analysis Facility, the boron content in geological samples with a spatial resolution of 1 µm is determined through nuclear reaction analysis. In the newly upgraded setup, a single detector has been replaced by a double sided silicon strip detector with 2048 segments. After optimization, boron content in geological samples as low as 1 µg g(-1) can be measured...
2017: Journal of Radioanalytical and Nuclear Chemistry
https://www.readbyqxmd.com/read/28102949/simultaneous-pet-mr-imaging-with-a-radio-frequency-penetrable-pet-insert
#20
Alexander M Grant, Brian J Lee, Chen-Ming Chang, Craig S Levin
PURPOSE: A brain sized radio frequency (RF)-penetrable PET insert has been designed for simultaneous operation with MRI systems. This system takes advantage of electro-optical coupling and battery power to electrically float the PET insert relative to the MRI ground, permitting RF signals to be transmitted through small gaps between the modules that form the PET ring. This design facilitates the use of the built-in body coil for RF transmission and thus could be inserted into any existing MR site wishing to achieve simultaneous PET/MR imaging...
January 2017: Medical Physics
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