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Sample records for digital pixel array

  1. Digital Pixel Sensor Array with Logarithmic Delta-Sigma Architecture

    Science.gov (United States)

    Mahmoodi, Alireza; Li, Jing; Joseph, Dileepan

    2013-01-01

    Like the human eye, logarithmic image sensors achieve wide dynamic range easily at video rates, but, unlike the human eye, they suffer from low peak signal-to-noise-and-distortion ratios (PSNDRs). To improve the PSNDR, we propose integrating a delta-sigma analog-to-digital converter (ADC) in each pixel. An image sensor employing this architecture is designed, built and tested in 0.18 micron complementary metal-oxide-semiconductor (CMOS) technology. It achieves a PSNDR better than state-of-the-art logarithmic sensors and comparable to the human eye. As the approach concerns an array of many ADCs, we use a small-area low-power delta-sigma design. For scalability, each pixel has its own decimator. The prototype is compared to a variety of other image sensors, linear and nonlinear, from industry and academia. PMID:23959239

  2. Digital Pixel Sensor Array with Logarithmic Delta-Sigma Architecture

    Directory of Open Access Journals (Sweden)

    Jing Li

    2013-08-01

    Full Text Available Like the human eye, logarithmic image sensors achieve wide dynamic range easily at video rates, but, unlike the human eye, they suffer from low peak signal-to-noise-and-distortion ratios (PSNDRs. To improve the PSNDR, we propose integrating a delta-sigma analog-to-digital converter (ADC in each pixel. An image sensor employing this architecture is designed, built and tested in 0.18 micron complementary metal-oxide-semiconductor (CMOS technology. It achieves a PSNDR better than state-of-the-art logarithmic sensors and comparable to the human eye. As the approach concerns an array of many ADCs, we use a small-area low-power delta-sigma design. For scalability, each pixel has its own decimator. The prototype is compared to a variety of other image sensors, linear and nonlinear, from industry and academia.

  3. Digital pixel sensor array with logarithmic delta-sigma architecture.

    Science.gov (United States)

    Mahmoodi, Alireza; Li, Jing; Joseph, Dileepan

    2013-08-16

    Like the human eye, logarithmic image sensors achieve wide dynamic range easily at video rates, but, unlike the human eye, they suffer from low peak signal-to-noise-and-distortion ratios (PSNDRs). To improve the PSNDR, we propose integrating a delta-sigma analog-to-digital converter (ADC) in each pixel. An image sensor employing this architecture is designed, built and tested in 0.18 micron complementary metal-oxide-semiconductor (CMOS) technology. It achieves a PSNDR better than state-of-the-art logarithmic sensors and comparable to the human eye. As the approach concerns an array of many ADCs, we use a small-area low-power delta-sigma design. For scalability, each pixel has its own decimator. The prototype is compared to a variety of other image sensors, linear and nonlinear, from industry and academia.

  4. Design, optimization and evaluation of a "smart" pixel sensor array for low-dose digital radiography

    Science.gov (United States)

    Wang, Kai; Liu, Xinghui; Ou, Hai; Chen, Jun

    2016-04-01

    Amorphous silicon (a-Si:H) thin-film transistors (TFTs) have been widely used to build flat-panel X-ray detectors for digital radiography (DR). As the demand for low-dose X-ray imaging grows, a detector with high signal-to-noise-ratio (SNR) pixel architecture emerges. "Smart" pixel is intended to use a dual-gate photosensitive TFT for sensing, storage, and switch. It differs from a conventional passive pixel sensor (PPS) and active pixel sensor (APS) in that all these three functions are combined into one device instead of three separate units in a pixel. Thus, it is expected to have high fill factor and high spatial resolution. In addition, it utilizes the amplification effect of the dual-gate photosensitive TFT to form a one-transistor APS that leads to a potentially high SNR. This paper addresses the design, optimization and evaluation of the smart pixel sensor and array for low-dose DR. We will design and optimize the smart pixel from the scintillator to TFT levels and validate it through optical and electrical simulation and experiments of a 4x4 sensor array.

  5. Focal plane array with modular pixel array components for scalability

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  6. A per-pixel Log2ADC for high dynamic range, 1000FPS digital focal plane arrays (DFPA)

    Science.gov (United States)

    Petilli, Eugene

    2016-09-01

    Intrinsix has developed a Digital Focal Plane Array (DFPA) architecture based on a novel piecewise linear Log2 ADC (LADC) with "lossless" analog compression which enables ultra-high dynamic range ROICs that use less power than other extended dynamic range technologies. The LADC provides dynamic range of 126dB with a constant 75dB SNR over the entire frame. The companding 13bit mantissa, 3bit radix per pixel LADCs compress the 21bit signals into efficient 16 bit data words. The Read Out IC (ROIC) is compatible with most IR and LWIR detectors including two-color SLS (photodiode) and uBolometers. The DFPA architecture leverages two (staggered frame prime and redundant) MIPI CSI-3 interfaces to achieve full HD DFPA at 1000 frames/sec; an equivalent uncompressed data rate of 100Gb/sec. The LADC uses direct injection into a moderate sized integrating capacitor and several comparators create a stream of multi-bit data values. These values are accumulated in an SRAM based log2ALU and the radix of the ALU is combined with the data to generate a feedback current to the integrating capacitor, closing the delta loop. The integration time and a single pole low pass IIR filter are configurable using control signals to the log2ALU. The feedback current is at least partially generated using PWM for high linearity.

  7. Mapping Electrical Crosstalk in Pixelated Sensor Arrays

    Science.gov (United States)

    Seshadri, Suresh (Inventor); Cole, David (Inventor); Smith, Roger M (Inventor); Hancock, Bruce R. (Inventor)

    2013-01-01

    The effects of inter pixel capacitance in a pixilated array may be measured by first resetting all pixels in the array to a first voltage, where a first image is read out, followed by resetting only a subset of pixels in the array to a second voltage, where a second image is read out, where the difference in the first and second images provide information about the inter pixel capacitance. Other embodiments are described and claimed.

  8. Mapping Electrical Crosstalk in Pixelated Sensor Arrays

    Science.gov (United States)

    Seshadri, Suresh (Inventor); Cole, David (Inventor); Smith, Roger M. (Inventor); Hancock, Bruce R. (Inventor)

    2017-01-01

    The effects of inter pixel capacitance in a pixilated array may be measured by first resetting all pixels in the array to a first voltage, where a first image is read out, followed by resetting only a subset of pixels in the array to a second voltage, where a second image is read out, where the difference in the first and second images provide information about the inter pixel capacitance. Other embodiments are described and claimed.

  9. CMOS digital pixel sensors: technology and applications

    Science.gov (United States)

    Skorka, Orit; Joseph, Dileepan

    2014-04-01

    CMOS active pixel sensor technology, which is widely used these days for digital imaging, is based on analog pixels. Transition to digital pixel sensors can boost signal-to-noise ratios and enhance image quality, but can increase pixel area to dimensions that are impractical for the high-volume market of consumer electronic devices. There are two main approaches to digital pixel design. The first uses digitization methods that largely rely on photodetector properties and so are unique to imaging. The second is based on adaptation of a classical analog-to-digital converter (ADC) for in-pixel data conversion. Imaging systems for medical, industrial, and security applications are emerging lower-volume markets that can benefit from these in-pixel ADCs. With these applications, larger pixels are typically acceptable, and imaging may be done in invisible spectral bands.

  10. The charge pump PLL clock generator designed for the 1.56 ns bin size time-to-digital converter pixel array of the Timepix3 readout ASIC

    CERN Document Server

    Fu, Y et al.

    2014-01-01

    Timepix3 is a newly developed pixel readout chip which is expected to be operated in a wide range of gaseous and silicon detectors. It is made of 256×256 pixels organized in a square pixel-array with 55 µm pitch. Oscillators running at 640 MHz are distributed across the pixel-array and allow for a highly accurate measurement of the arrival time of a hit. This paper concentrates on a low-jitter phase locked loop (PLL) that is located in the chip periphery. This PLL provides a control voltage which regulates the actual frequency of the individual oscillators, allowing for compensation of process, voltage, and temperature variations.

  11. Smart pixel imaging with computational-imaging arrays

    Science.gov (United States)

    Fernandez-Cull, Christy; Tyrrell, Brian M.; D'Onofrio, Richard; Bolstad, Andrew; Lin, Joseph; Little, Jeffrey W.; Blackwell, Megan; Renzi, Matthew; Kelly, Mike

    2014-07-01

    Smart pixel imaging with computational-imaging arrays (SPICA) transfers image plane coding typically realized in the optical architecture to the digital domain of the focal plane array, thereby minimizing signal-to-noise losses associated with static filters or apertures and inherent diffraction concerns. MIT Lincoln Laboratory has been developing digitalpixel focal plane array (DFPA) devices for many years. In this work, we leverage legacy designs modified with new features to realize a computational imaging array (CIA) with advanced pixel-processing capabilities. We briefly review the use of DFPAs for on-chip background removal and image plane filtering. We focus on two digital readout integrated circuits (DROICS) as CIAs for two-dimensional (2D) transient target tracking and three-dimensional (3D) transient target estimation using per-pixel coded-apertures or flutter shutters. This paper describes two DROICs - a SWIR pixelprocessing imager (SWIR-PPI) and a Visible CIA (VISCIA). SWIR-PPI is a DROIC with a 1 kHz global frame rate with a maximum per-pixel shuttering rate of 100 MHz, such that each pixel can be modulated by a time-varying, pseudorandom, and duo-binary signal (+1,-1,0). Combining per-pixel time-domain coding and processing enables 3D (x,y,t) target estimation with limited loss of spatial resolution. We evaluate structured and pseudo-random encoding strategies and employ linear inversion and non-linear inversion using total-variation minimization to estimate a 3D data cube from a single 2D temporally-encoded measurement. The VISCIA DROIC, while low-resolution, has a 6 kHz global frame rate and simultaneously encodes eight periodic or aperiodic transient target signatures at a maximum rate of 50 MHz using eight 8-bit counters. By transferring pixel-based image plane coding to the DROIC and utilizing sophisticated processing, our CIAs enable on-chip temporal super-resolution.

  12. Serial Pixel Analog-to-Digital Converter

    Energy Technology Data Exchange (ETDEWEB)

    Larson, E D

    2010-02-01

    This method reduces the data path from the counter to the pixel register of the analog-to-digital converter (ADC) from as many as 10 bits to a single bit. The reduction in data path width is accomplished by using a coded serial data stream similar to a pseudo random number (PRN) generator. The resulting encoded pixel data is then decoded into a standard hexadecimal format before storage. The high-speed serial pixel ADC concept is based on the single-slope integrating pixel ADC architecture. Previous work has described a massively parallel pixel readout of a similar architecture. The serial ADC connection is similar to the state-of-the art method with the exception that the pixel ADC register is a shift register and the data path is a single bit. A state-of-the-art individual-pixel ADC uses a single-slope charge integration converter architecture with integral registers and “one-hot” counters. This implies that parallel data bits are routed among the counter and the individual on-chip pixel ADC registers. The data path bit-width to the pixel is therefore equivalent to the pixel ADC bit resolution.

  13. A PFM based digital pixel with off-pixel residue measurement for 15μm pitch MWIR FPAs

    Science.gov (United States)

    Abbasi, Shahbaz; Shafique, Atia; Galioglu, Arman; Ceylan, Omer; Yazici, Melik; Gurbuz, Yasar

    2016-05-01

    Digital pixels based on pulse frequency modulation (PFM) employ counting techniques to achieve very high charge handling capability compared to their analog counterparts. Moreover, extended counting methods making use of leftover charge (residue) on the integration capacitor help improve the noise performance of these pixels. However, medium wave infrared (MWIR) focal plane arrays (FPAs) having smaller pixel pitch are constrained in terms of pixel area which makes it difficult to add extended counting circuitry to the pixel. Thus, this paper investigates the performance of digital pixels employing off-pixel residue measurement. A circuit prototype of such a pixel has been designed for 15μm pixel pitch and fabricated in 90nm CMOS. The prototype is composed of a pixel front-end based on a PFM loop. The frontend is a modified version of conventional design providing a means for buffering the signal that needs to be converted to a digital value by an off-pixel ADC. The pixel has an integration phase and a residue measurement phase. Measured integration performance of the pixel has been reported in this paper for various detector currents and integration times.

  14. Simulation study of pixel detector charge digitization

    Science.gov (United States)

    Wang, Fuyue; Nachman, Benjamin; Sciveres, Maurice; Lawrence Berkeley National Laboratory Team

    2017-01-01

    Reconstruction of tracks from nearly overlapping particles, called Tracking in Dense Environments (TIDE), is an increasingly important component of many physics analyses at the Large Hadron Collider as signatures involving highly boosted jets are investigated. TIDE makes use of the charge distribution inside a pixel cluster to resolve tracks that share one of more of their pixel detector hits. In practice, the pixel charge is discretized using the Time-over-Threshold (ToT) technique. More charge information is better for discrimination, but more challenging for designing and operating the detector. A model of the silicon pixels has been developed in order to study the impact of the precision of the digitized charge distribution on distinguishing multi-particle clusters. The output of the GEANT4-based simulation is used to train neutral networks that predict the multiplicity and location of particles depositing energy inside one cluster of pixels. By studying the multi-particle cluster identification efficiency and position resolution, we quantify the trade-off between the number of ToT bits and low-level tracking inputs. As both ATLAS and CMS are designing upgraded detectors, this work provides guidance for the pixel module designs to meet TIDE needs. Work funded by the China Scholarship Council and the Office of High Energy Physics of the U.S. Department of Energy under contract DE-AC02-05CH11231.

  15. Implementation of TDI based digital pixel ROIC with 15μm pixel pitch

    Science.gov (United States)

    Ceylan, Omer; Shafique, Atia; Burak, A.; Caliskan, Can; Abbasi, Shahbaz; Yazici, Melik; Gurbuz, Yasar

    2016-05-01

    A 15um pixel pitch digital pixel for LWIR time delay integration (TDI) applications is implemented which occupies one fourth of pixel area compared to previous digital TDI implementation. TDI is implemented on 8 pixels with oversampling rate of 2. ROIC provides 16 bits output with 8 bits of MSB and 8 bits of LSB. Pixel can store 75 M electrons with a quantization noise of 500 electrons. Digital pixel TDI implementation is advantageous over analog counterparts considering power consumption, chip area and signal-to-noise ratio. Digital pixel TDI ROIC is fabricated with 0.18um CMOS process. In digital pixel TDI implementation photocurrent is integrated on a capacitor in pixel and converted to digital data in pixel. This digital data triggers the summation counters which implements TDI addition. After all pixels in a row contribute, the summed data is divided to the number of TDI pixels(N) to have the actual output which is square root of N improved version of a single pixel output in terms of signal-to-noise-ratio (SNR).

  16. Noise in a CMOS digital pixel sensor

    Institute of Scientific and Technical Information of China (English)

    Zhang Chi; Yao Suying; Xu Jiangtao

    2011-01-01

    Based on the study of noise performance in CMOS digital pixel sensor (DPS),a mathematical model of noise is established with the pulse-width-modulation (PWM) principle.Compared with traditional CMOS image sensors,the integration time is different and A/D conversion is implemented in each PWM DPS pixel.Then,the quantitative calculating formula of system noise is derived.It is found that dark current shot noise is the dominant noise source in low light region while photodiode shot noise becomes significantly important in the bright region.In this model,photodiode shot noise does not vary with luminance,but dark current shot noise does.According to increasing photodiode capacitance and the comparator's reference voltage or optimizing the mismatch in the comparator,the total noise can be reduced.These results serve as a guideline for the design of PWM DPS.

  17. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The bump-bonded silicon pixel detector, developed at CERN by the EP-MIC group, is shown here in its ceramic carrier. Both represent the ISPA-tube anode. The chip features between 1024 (called OMEGA-1) and 8196 (ALICE-1) active pixels.

  18. Two-dimensional pixel array image sensor for protein crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Beuville, E.; Beche, J.-F.; Cork, C. [and others

    1996-07-01

    A 2D pixel array image sensor module has been designed for time resolved Protein Crystallography. This smart pixels detector significantly enhances time resolved Laue Protein crystallography by two to three orders of magnitude compared to existing sensors like films or phosphor screens coupled to CCDs. The resolution in time and dynamic range of this type of detector will allow one to study the evolution of structural changes that occur within the protein as a function of time. This detector will also considerably accelerate data collection in static Laue or monochromatic crystallography and make better use of the intense beam delivered by synchrotron light sources. The event driven pixel array detectors, based on the column Architecture, can provide multiparameter information (energy discrimination, time), with sparse and frameless readout without significant dead time. The prototype module consists of a 16x16 pixel diode array bump-bonded to the integrated circuit. The detection area is 150x150 square microns.

  19. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Application components of ISPA tubes are shown: the CERN-developed anode chip, special windows for gamma and x-ray detection, scintillating crystal and fibre arrays for imaging and tracking of ionizing particles.

  20. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The ISPA tube is a position-sensitive photon detector. It belongs to the family of hybrid photon detectors (HPD), recently developed by CERN and INFN with leading photodetector firms. HPDs confront in a vacuum envelope a photocathode and a silicon detector. This can be a single diode or a pixelized detector. The electrons generated by the photocathode are efficiently detected by the silicon anode by applying a high-voltage difference between them. ISPA tube can be used in high-energy applications as well as bio-medical and imaging applications.

  1. Development of CMOS Pixel Sensors with digital pixel dedicated to future particle physics experiments

    Science.gov (United States)

    Zhao, W.; Wang, T.; Pham, H.; Hu-Guo, C.; Dorokhov, A.; Hu, Y.

    2014-02-01

    Two prototypes of CMOS pixel sensor with in-pixel analog to digital conversion have been developed in a 0.18 μm CIS process. The first design integrates a discriminator into each pixel within an area of 22 × 33 μm2 in order to meet the requirements of the ALICE inner tracking system (ALICE-ITS) upgrade. The second design features 3-bit charge encoding inside a 35 × 35 μm2 pixel which is motivated by the specifications of the outer layers of the ILD vertex detector (ILD-VXD). This work aims to validate the concept of in-pixel digitization which offers higher readout speed, lower power consumption and less dead zone compared with the column-level charge encoding.

  2. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    On the table, under the scrutiny of some collaboration members, an ISPA tube (upper-left of the table) with some of its application components is shown: they consist of the CERN-developed anode chip, special windows for gamma and x-ray detection, scintillating crystal and fibre arrays for imaging and tracking of ionizing particles.

  3. A 400 KHz line rate 2048-pixel stitched SWIR linear array

    Science.gov (United States)

    Anchlia, Ankur; Vinella, Rosa M.; Gielen, Daphne; Wouters, Kristof; Vervenne, Vincent; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; De Gaspari, Danny; Das, Jo; Merken, Patrick

    2016-05-01

    Xenics has developed a family of stitched SWIR long linear arrays that operate up to 400 KHz of line rate. These arrays serve medical and industrial applications that require high line rates as well as space applications that require long linear arrays. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long array to run at a high line rates irrespective of the array length, which limits the line rate in a traditional linear array. The ROIC is flip-chipped with InGaAs detector arrays. The FPA has a pixel pitch of 12.5μm and has two pixel flavors: square (12.5μm) and rectangular (250μm). The frontend circuit is based on Capacitive Trans-impedance Amplifier (CTIA) to attain stable detector bias, and good linearity and signal integrity, especially at high speeds. The CTIA has an input auto-zero mechanism that allows to have low detector bias (<20mV). An on-chip Correlated Double Sample (CDS) facilitates removal of CTIA KTC and 1/f noise, and other offsets, achieving low noise performance. There are five gain modes in the FPA giving the full well range from 85Ke- to 40Me-. The measured input referred noise is 35e-rms in the highest gain mode. The FPA operates in Integrate While Read mode and, at a master clock rate of 60MHz and a minimum integration time of 1.4μs, achieves the highest line rate of 400 KHz. In this paper, design details and measurements results are presented in order to demonstrate the array performance.

  4. Serial pixel analog-to-digital converter (ADC)

    Science.gov (United States)

    Larson, Eric D.

    2010-02-01

    This method reduces the data path from the counter to the pixel register of the analog-to-digital converter (ADC) from as many as 10 bits to a single bit. The reduction in data path width is accomplished by using a coded serial data stream similar to a pseudo random number (PRN) generator. The resulting encoded pixel data is then decoded into a standard hexadecimal format before storage. The high-speed serial pixel ADC concept is based on the single-slope integrating pixel ADC architecture. Previous work has described a massively parallel pixel readout of a similar architecture. The serial ADC connection is similar to the state-of-the art method with the exception that the pixel ADC register is a shift register and the data path is a single bit. A state-of-the-art individual-pixel ADC uses a single-slope charge integration converter architecture with integral registers and "one-hot" counters. This implies that parallel data bits are routed among the counter and the individual on-chip pixel ADC registers. The data path bit-width to the pixel is therefore equivalent to the pixel ADC bit resolution.

  5. Active-Pixel Image Sensor With Analog-To-Digital Converters

    Science.gov (United States)

    Fossum, Eric R.; Mendis, Sunetra K.; Pain, Bedabrata; Nixon, Robert H.

    1995-01-01

    Proposed single-chip integrated-circuit image sensor contains 128 x 128 array of active pixel sensors at 50-micrometer pitch. Output terminals of all pixels in each given column connected to analog-to-digital (A/D) converter located at bottom of column. Pixels scanned in semiparallel fashion, one row at time; during time allocated to scanning row, outputs of all active pixel sensors in row fed to respective A/D converters. Design of chip based on complementary metal oxide semiconductor (CMOS) technology, and individual circuit elements fabricated according to 2-micrometer CMOS design rules. Active pixel sensors designed to operate at video rate of 30 frames/second, even at low light levels. A/D scheme based on first-order Sigma-Delta modulation.

  6. X-ray Characterization of a Multichannel Smart-Pixel Array Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Steve; Haji-Sheikh, Michael; Huntington, Andrew; Kline, David; Lee, Adam; Li, Yuelin; Rhee, Jehyuk; Tarpley, Mary; Walko, Donald A.; Westberg, Gregg; Williams, George; Zou, Haifeng; Landahl, Eric

    2016-01-01

    The Voxtel VX-798 is a prototype X-ray pixel array detector (PAD) featuring a silicon sensor photodiode array of 48 x 48 pixels, each 130 mu m x 130 mu m x 520 mu m thick, coupled to a CMOS readout application specific integrated circuit (ASIC). The first synchrotron X-ray characterization of this detector is presented, and its ability to selectively count individual X-rays within two independent arrival time windows, a programmable energy range, and localized to a single pixel is demonstrated. During our first trial run at Argonne National Laboratory's Advance Photon Source, the detector achieved a 60 ns gating time and 700 eV full width at half-maximum energy resolution in agreement with design parameters. Each pixel of the PAD holds two independent digital counters, and the discriminator for X-ray energy features both an upper and lower threshold to window the energy of interest discarding unwanted background. This smart-pixel technology allows energy and time resolution to be set and optimized in software. It is found that the detector linearity follows an isolated dead-time model, implying that megahertz count rates should be possible in each pixel. Measurement of the line and point spread functions showed negligible spatial blurring. When combined with the timing structure of the synchrotron storage ring, it is demonstrated that the area detector can perform both picosecond time-resolved X-ray diffraction and fluorescence spectroscopy measurements.

  7. Implementation of pixel level digital TDI for scanning type LWIR FPAs

    Science.gov (United States)

    Ceylan, Omer; Kayahan, Huseyin; Yazici, Melik; Afridi, Sohaib; Shafique, Atia; Gurbuz, Yasar

    2014-07-01

    Implementation of a CMOS digital readout integrated circuit (DROIC) based on pixel level digital time delay integration (TDI) for scanning type LWIR focal plane arrays (FPAs) is presented. TDI is implemented on 8 pixels with over sampling rate of 3. Analog signal integrated on integration capacitor is converted to digital domain in pixel, and digital data is transferred to TDI summation counters, where contributions of 8 pixels are added. Output data is 16 bit, where 8 bits are allocated for most significant bits and 8 bits for least significant bits. Control block of the ROIC, which is responsible of generating timing diagram for switches controlling the pixels and summation counters, is realized with VerilogHDL. Summation counters and parallel-to-serial converter to convert 16 bit parallel output data to single bit output are also realized with Verilog HDL. Synthesized verilog netlists are placed&routed and combined with analog under-pixel part of the design. Quantization noise of analog-to-digital conversion is less than 500e-. Since analog signal is converted to digital domain in-pixel, inaccuracies due to analog signal routing over large chip area is eliminated. ROIC is fabricated with 0.18μm CMOS process and chip area is 10mm2. Post-layout simulation results of the implemented design are presented. ROIC is programmable through serial or parallel interface. Input referred noise of ROIC is less than 750 rms electron, while power consumption is less than 30mW. ROIC is designed to perform in cryogenic temperatures.

  8. A new pixel level digital read out integrated circuits for ultraviolet imaging sensors

    Science.gov (United States)

    Xu, Bin; Lan, Tian-yi; Yuan, Yong-gang; Li, Xiang-yang

    2014-11-01

    The ultraviolet imaging sensors consist of two important parts: the array of detectors and the read out integrated circuits. Along with the demand for the fine resolution, large input dynamic range and high integration degree of the imaging sensors, the functions of read out integrated circuits are becoming more and more important. The on chip analog to digital conversion is the main directions of research on this area. In this paper, we presented a new digital read out integrated circuits for ultraviolet imaging sensors. The proposed circuits have an analog to digital converter in each pixel, which enable the parallel analog to digital conversion of the whole pixel array. The developed circuits have a 50um×50um pixel area with a 128×128 size, and are designed in a 0.35um four metal double poly mixed signal CMOS process. The simulation results show that the designed analog to digital converter has an accuracy of 0.2mV and can achieve the dynamic range of 88dB. The proposed circuits realize the low noise and high speed digital output of read out integrated circuits for ultraviolet imaging sensors.

  9. Hardware architecture of high-performance digital hologram generator on the basis of a pixel-by-pixel calculation scheme.

    Science.gov (United States)

    Seo, Young-Ho; Lee, Yoon-Hyuk; Yoo, Ji-Sang; Kim, Dong-Wook

    2012-06-20

    In this paper we propose a hardware architecture for high-speed computer-generated hologram generation that significantly reduces the number of memory access times to avoid the bottleneck in the memory access operation. For this, we use three main schemes. The first is pixel-by-pixel calculation, rather than light source-by-source calculation. The second is a parallel calculation scheme extracted by modifying the previous recursive calculation scheme. The last scheme is a fully pipelined calculation scheme and exactly structured timing scheduling, achieved by adjusting the hardware. The proposed hardware is structured to calculate a row of a computer-generated hologram in parallel and each hologram pixel in a row is calculated independently. It consists of and input interface, an initial parameter calculator, hologram pixel calculators, a line buffer, and a memory controller. The implemented hardware to calculate a row of a 1920×1080 computer-generated hologram in parallel uses 168,960 lookup tables, 153,944 registers, and 19,212 digital signal processing blocks in an Altera field programmable gate array environment. It can stably operate at 198 MHz. Because of three schemes, external memory bandwidth is reduced to approximately 1/20,000 of the previous ones at the same calculation speed.

  10. Digital column readout architectures for hybrid pixel detector readout chips

    CERN Document Server

    Poikela, T; Westerlund, T; Buytaert, J; Campbell, M; De Gaspari, M; Llopart, X; Wyllie, K; Gromov, V; Kluit, R; van Beuzekom, M; Zappon, F; Zivkovic, V; Brezina, C; Desch, K; Fu, Y; Kruth, A

    2014-01-01

    In this paper, two digital column architectures suitable for sparse readout of data from a pixel matrix in trigger-less applications are presented. Each architecture reads out a pixel matrix of 256 x 256 pixels with a pixel pitch of 55 µm. The first architecture has been implemented in the Timepix3 chip, and this is presented together with initial measurements. Simulation results and measured data are compared. The second architecture has been designed for Velopix, a readout chip planned for the LHCb VELO upgrade. Unlike Timepix3, this has to be tolerant to radiation-induced single-event effects. Results from post-layout simulations are shown with the circuit architectures.

  11. Parallel pipeline networking and signal processing with field-programmable gate arrays (FPGAs) and VCSEL-MSM smart pixels

    Science.gov (United States)

    Kuznia, C. B.; Sawchuk, Alexander A.; Zhang, Liping; Hoanca, Bogdan; Hong, Sunkwang; Min, Chris; Pansatiankul, Dhawat E.; Alpaslan, Zahir Y.

    2000-05-01

    We present a networking and signal processing architecture called Transpar-TR (Translucent Smart Pixel Array-Token- Ring) that utilizes smart pixel technology to perform 2D parallel optical data transfer between digital processing nodes. Transpar-TR moves data through the network in the form of 3D packets (2D spatial and 1D time). By utilizing many spatial parallel channels, Transpar-TR can achieve high throughput, low latency communication between nodes, even with each channel operating at moderate data rates. The 2D array of optical channels is created by an array of smart pixels, each with an optical input and optical output. Each smart pixel consists of two sections, an optical network interface and ALU-based processor with local memory. The optical network interface is responsible for transmitting and receiving optical data packets using a slotted token ring network protocol. The smart pixel array operates as a single-instruction multiple-data processor when processing data. The Transpar-TR network, consisting of networked smart pixel arrays, can perform pipelined parallel processing very efficiently on 2D data structures such as images and video. This paper discusses the Transpar-TR implementation in which each node is the printed circuit board integration of a VCSEL-MSM chip, a transimpedance receiver array chip and an FPGA chip.

  12. New Active Digital Pixel Circuit for CMOS Image Sensor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2μm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter.

  13. Digital Power Consumption Estimations for CHIPIX65 Pixel Readout Chip

    CERN Document Server

    Marcotulli, Andrea

    2016-01-01

    New hybrid pixel detectors with improved resolution capable of dealing with hit rates up to 3 GHz/cm2 will be required for future High Energy Physics experiments in the Large Hadron Collider (LHC) at CERN. Given this, the RD53 collaboration works on the design of the next generation pixel readout chip needed for both the ATLAS and CMS detector phase 2 pixel upgrades. For the RD53 demonstrator chip in 65nm CMOS technology, different architectures are considered. In particular the purpose of this work is estimating the power consumption of the digital architecture of the readout ASIC developed by CHIPIX65 project of the INFN National Scientific Committee. This has been done with modern chip design tools integrated with the VEPIX53 simulation framework that has been developed within the RD53 collaboration in order to assess the performance of the system in very high rate, high energy physics experiments.

  14. Light weight digital array SAR

    NARCIS (Netherlands)

    Otten, M.; Maas, N.; Bolt, R.; Anitori, L.

    2010-01-01

    A light weight SAR has been designed, suitable for short range tactical UAVs, consisting of a fully digital receive array, and a very compact active transmit antenna. The weight of the complete RF front is expected to be below 3 kg, with a power consumption below 30 W. This X-band system can provide

  15. A 128 pixel linear array for radiotherapy quality assurance

    Science.gov (United States)

    Franco, L.; Gómez, F.; Iglesias, A.; Lobato, R.; Marín, J.; Mosquera, J.; Pardo, J.; Pazos, A.; Pena, J.; Pombar, M.; Rodríguez, A.; Saavedra, D.; Sendón, J.; Yañez, A.

    2004-12-01

    New radiotherapy techniques require detectors able to verify and monitor the clinical beam with high spatial resolution and fast response. Room temperature organic liquid ionization detectors are becoming an alternative to standard air ionization chambers, due to their tissue equivalent behavior, their sensibility and small directional dependence. A liquid isooctane filled ionization linear array for radiotherapy quality assurance has been designed, built and tested. The detector consists of 128 pixels, each of them with an area of 1.7 mm×1.7 mm and a gap of 0.5 mm. The small pixel size makes the detector ideal for high gradient beam profiles like those present in Intensity Modulated Radiation Therapy. The gap and the polarization voltage have been chosen in order to guarantee a linear relationship between the dose rate and the readout signal at high dose rates. As readout electronics we use the X-ray Data Acquisition System with the Xchip developed by the CCLRC.In the first device tests we have confirmed linearity up to a 6.7 Gy/min dose rate with a deviation less than 1%. A profile with a signal-to-noise ratio around 500 can be obtained for a 4 Gy/min dose rate with a 10 ms integration time.

  16. A 128 pixel linear array for radiotherapy quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Franco, L. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain); Gomez, F. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain)]. E-mail: faustgr@usc.es; Iglesias, A. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain); Lobato, R. [Hospital Clinico Universitario de Santiago, 15706 Santiago (Spain); Marin, J. [CIEMAT, Laboratorio de Electronica y Automatica, 28040 Madrid Spain (Spain); Mosquera, J. [Hospital Clinico Universitario de Santiago, 15706 Santiago (Spain); Pardo, J. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain)]. E-mail: juanpm@usc.es; Pazos, A. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain); Pena, J. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain); Pombar, M. [Hospital Clinico Universitario de Santiago, 15706 Santiago (Spain); Rodriguez, A. [Departmento de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, campus sur s/n, 15782 Santiago de Compostela (Spain); Saavedra, D. [Universidade da Coruna, Dpto. de Enxeneria Industrial II, 15403 Ferrol Spain (Spain); Sendon, J. [Hospital Clinico Universitario de Santiago, 15706 Santiago (Spain); Yanez, A. [Universidade da Coruna, Dpto. de Enxeneria Industrial II, 15403 Ferrol Spain (Spain)

    2004-12-11

    New radiotherapy techniques require detectors able to verify and monitor the clinical beam with high spatial resolution and fast response. Room temperature organic liquid ionization detectors are becoming an alternative to standard air ionization chambers, due to their tissue equivalent behavior, their sensibility and small directional dependence. A liquid isooctane filled ionization linear array for radiotherapy quality assurance has been designed, built and tested. The detector consists of 128 pixels, each of them with an area of 1.7mmx1.7mm and a gap of 0.5mm. The small pixel size makes the detector ideal for high gradient beam profiles like those present in Intensity Modulated Radiation Therapy. The gap and the polarization voltage have been chosen in order to guarantee a linear relationship between the dose rate and the readout signal at high dose rates. As readout electronics we use the X-ray Data Acquisition System with the Xchip developed by the CCLRC.In the first device tests we have confirmed linearity up to a 6.7Gy/min dose rate with a deviation less than 1%. A profile with a signal-to-noise ratio around 500 can be obtained for a 4Gy/min dose rate with a 10 ms integration time.

  17. Nano-fabricated pixelated micropolarizer array for visible imaging polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhigang; Cheng, Teng; Qiu, Kang; Zhang, Qingchuan, E-mail: zhangqc@ustc.edu.cn, E-mail: wgchu@nanoctr.cn; Wu, Xiaoping [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027 (China); Dong, Fengliang; Chu, Weiguo, E-mail: zhangqc@ustc.edu.cn, E-mail: wgchu@nanoctr.cn [Nanofabrication Laboratory, National Center for Nanoscience and Technology, Beijing 100190 (China)

    2014-10-15

    Pixelated micropolarizer array (PMA) is a novel concept for real-time visible imaging polarimetry. A 320 × 240 aluminum PMA fabricated by electron beam lithography is described in this paper. The period, duty ratio, and depth of the grating are 140 nm, 0.5, and 100 nm, respectively. The units are standard square structures and the metal nanowires of the grating are collimating and uniformly thick. The extinction ratio of 75 and the maximum polarization transmittance of 78.8% demonstrate that the PMA is suitable for polarization imaging. When the PMA is applied to real-time polarization imaging, the degree of linear polarization image and the angle of linear polarization image are calculated from a single frame image. The polarized target object is highlighted from the unpolarized background, and the surface contour of the target object can be reflected by the polarization angle.

  18. Nano-fabricated pixelated micropolarizer array for visible imaging polarimetry.

    Science.gov (United States)

    Zhang, Zhigang; Dong, Fengliang; Cheng, Teng; Qiu, Kang; Zhang, Qingchuan; Chu, Weiguo; Wu, Xiaoping

    2014-10-01

    Pixelated micropolarizer array (PMA) is a novel concept for real-time visible imaging polarimetry. A 320 × 240 aluminum PMA fabricated by electron beam lithography is described in this paper. The period, duty ratio, and depth of the grating are 140 nm, 0.5, and 100 nm, respectively. The units are standard square structures and the metal nanowires of the grating are collimating and uniformly thick. The extinction ratio of 75 and the maximum polarization transmittance of 78.8% demonstrate that the PMA is suitable for polarization imaging. When the PMA is applied to real-time polarization imaging, the degree of linear polarization image and the angle of linear polarization image are calculated from a single frame image. The polarized target object is highlighted from the unpolarized background, and the surface contour of the target object can be reflected by the polarization angle.

  19. Design of 90×8 ROIC with pixel level digital TDI implementation for scanning type LWIR FPAs

    Science.gov (United States)

    Ceylan, Omer; Kayahan, Huseyin; Yazici, Melik; Gurbuz, Yasar

    2013-06-01

    Design of a 90×8 CMOS readout integrated circuit (ROIC) based on pixel level digital time delay integration (TDI) for scanning type LWIR focal plane arrays (FPAs) is presented. TDI is implemented on 8 pixels which improves the SNR of the system with a factor of √8. Oversampling rate of 3 improves the spatial resolution of the system. TDI operation is realized with a novel under-pixel analog-to-digital converter, which improves the noise performance of ROIC with a lower quantization noise. Since analog signal is converted to digital domain in-pixel, non-uniformities and inaccuracies due to analog signal routing over large chip area is eliminated. Contributions of each pixel for proper TDI operation are added in summation counters, no op-amps are used for summation, hence power consumption of ROIC is lower than its analog counterparts. Due to lack of multiple capacitors or summation amplifiers, ROIC occupies smaller chip area compared to its analog counterparts. ROIC is also superior to its digital counterparts due to novel digital TDI implementation in terms of power consumption, noise and chip area. ROIC supports bi-directional scan, multiple gain settings, bypass operation, automatic gain adjustment, pixel select/deselect, and is programmable through serial or parallel interface. Input referred noise of ROIC is less than 750 rms electrons, while power consumption is less than 20mW. ROIC is designed to perform both in room and cryogenic temperatures.

  20. Multiplexed Readout for 1000-pixel Arrays of Microwave Kinetic Inductance Detectors

    CERN Document Server

    van Rantwijk, Joris; van Loon, Dennis; Yates, Stephen; Baryshev, Andrey; Baselmans, Jochem

    2015-01-01

    Microwave Kinetic Inductance Detectors (MKIDs) are the most attractive radiation detectors for far-infrared and sub-mm astronomy: They combine ultimate sensitivity with the possibility to create very large detector arrays, in excess of 10 000 pixels. This is possible by reading-out the arrays using RF frequency division multiplexing, which allows multiplexing ratios in excess of 1000 pixels per readout line. We describe a novel readout system for large arrays of MKIDs, operating in a 2 GHz band in the 4-8 GHz range. The readout, which is a combination of a digital front- and back-end and an analog up- and down-converter system, can read out up to 4000 detectors simultaneously with 1 kHz datarate. The system achieves a readout noise power spectral density of -98 dBc/Hz while reading 1000 carriers simultaneously, which scales linear with the number of carriers. We demonstrate that 4000 state-of-the-art Aluminium-NbTiN MKIDs can be read out without deteriorating their intrinsic performance.

  1. Design of a 3D-IC multi-resolution digital pixel sensor

    Science.gov (United States)

    Brochard, N.; Nebhen, J.; Dubois, J.; Ginhac, D.

    2016-04-01

    This paper presents a digital pixel sensor (DPS) integrating a sigma-delta analog-to-digital converter (ADC) at pixel level. The digital pixel includes a photodiode, a delta-sigma modulation and a digital decimation filter. It features adaptive dynamic range and multiple resolutions (up to 10-bit) with a high linearity. A specific row decoder and column decoder are also designed to permit to read a specific pixel chosen in the matrix and its neighborhood of 4 x 4. Finally, a complete design with the CMOS 130 nm 3D-IC FaStack Tezzaron technology is also described, revealing a high fill-factor of about 80%.

  2. Development of Kilo-Pixel Arrays of Transition-Edge Sensors for X-Ray Spectroscopy

    Science.gov (United States)

    Adams, J. S.; Bandler, S. R.; Busch, S. E.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; Kilbourne, C. A.; Leutenegger, M. A.; Porst, J.-P.; Porter, F. S.; Ray, C. A.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.; Doriese, W. B.; Fowler, J. W.; Hilton, G. C.; Irwin, K. D.; Reintsema, C. D.; Smith, D. R.; Swetz, D. S.

    2012-01-01

    We are developing kilo-pixel arrays of transition-edge sensor (TES) microcalorimeters for future X-ray astronomy observatories or for use in laboratory astrophysics applications. For example, Athena/XMS (currently under study by the european space agency) would require a close-packed 32x32 pixel array on a 250-micron pitch with pixel/second. We present characterization of 32x32 arrays. These detectors will be readout using state of the art SQUID based time-domain multiplexing (TDM). We will also present the latest results in integrating these detectors and the TDM readout technology into a 16 row x N column field-able instrument.

  3. Photonic Heterodyne Pixel for Imaging Arrays at Microwave and MM-Wave Frequencies

    Directory of Open Access Journals (Sweden)

    Á. R. Criado

    2012-01-01

    Full Text Available The use of photonic heterodyne receivers based on semiconductor optical amplifiers to be used in imaging arrays at several GHz frequencies is evaluated. With this objective, a imaging array based on such photonic pixels has been fabricated and characterized. Each of the receiving optoelectronic pixels is composed of an antipodal linear tapered slot antenna (LTSA that sends the received RF signal directly to the electrical port of a semiconductor opticalamplifier (SOA acting as the optoelectronic mixer. Both the local oscillator (LO and the intermediate frequency (IF signals are directly distributed to/from the array pixels using fiber optics, that allows for remote LO generation and IF processing to recover the image. The results shown in this work demonstrate that the performances of the optoelectronic imaging array are similar to a reference all-electronic array, revealing the possibility of using this photonic architecture in future high-density, scalable, compact imaging arrays in microwave and millimeter wave ranges.

  4. Study of the characteristics of a scintillation array and single pixels for nuclear medicine imaging applications

    Institute of Scientific and Technical Information of China (English)

    ZHU Jie; MA Hong-Guang; MA Wen-Yan; ZENG Hui; WANG Zhao-Min; XU Zi-Zong

    2009-01-01

    By using a pixelized Nal(T1) crystal array coupled to a R2486 PSPMT, the characteristics of the array and of a single pixel, such as the light output, energy resolution, peak-to-valley ratio (P/V) and imaging performance of the detector were studied. The pixel size of the NaI(TI) scintillation pixel array is 2 min×2 mm×5 mm. There are in total 484 pixels in a 22~22 matrix. In the pixel spectrum an average peak-to-valley ratio (P/V) of 16 was obtained. In the image of all the pixels, good values for the Peak-to-Valley ratios could be achieved, namely a mean of 17, a maximum of 45 and the average peak FWHM (the average value of intrinsic spatial resolution) of 2.3 mm. However, the PSPMT non-uniform response and the scintillation pixels array inhomogeneities degrade the imaging performance of the detector.

  5. CMOS-compatible PureGaB Ge-on-Si APD pixel arrays

    NARCIS (Netherlands)

    Sammak, Amir; Aminian, Mahdi; Nanver, Lis Karen; Charbon, Edoardo

    2016-01-01

    Pure gallium and pure boron (PureGaB) Ge-on-Si photodiodes were fabricated in a CMOS compatible process and operated in linear and avalanche mode. Three different pixel geometries with very different area-to-perimeter ratios were investigated in linear arrays of 300 pixels with each a size of 26 × 2

  6. IDSAC-IUCAA digital sampler array controller

    Science.gov (United States)

    Chattopadhyay, Sabyasachi; Chordia, Pravin; Ramaprakash, A. N.; Burse, Mahesh P.; Joshi, Bhushan; Chillal, Kalpesh

    2016-07-01

    In order to run the large format detector arrays and mosaics that are required by most astronomical instruments, readout electronic controllers are required which can process multiple CCD outputs simultaneously at high speeds and low noise levels. These CCD controllers need to be modular and configurable, should be able to run multiple detector types to cater to a wide variety of requirements. IUCAA Digital Sampler Array Controller (IDSAC), is a generic CCD Controller based on a fully scalable architecture which is adequately flexible and powerful enough to control a wide variety of detectors used in ground based astronomy. The controller has a modular backplane architecture that consists of Single Board Controller Cards (SBCs) and can control up to 5 CCDs (mosaic or independent). Each Single Board Controller (SBC) has all the resources to a run Single large format CCD having up to four outputs. All SBCs are identical and are easily interchangeable without needing any reconfiguration. A four channel video processor on each SBC can process up to four output CCDs with or without dummy outputs at 0.5 Megapixels/Sec/Channel with 16 bit resolution. Each SBC has a USB 2.0 interface which can be connected to a host computer via optional USB to Fibre converters. The SBC uses a reconfigurable hardware (FPGA) as a Master Controller. IDSAC offers Digital Correlated Double Sampling (DCDS) to eliminate thermal kTC noise. CDS performed in Digital domain (DCDS) has several advantages over its analog counterpart, such as - less electronics, faster readout and easier post processing. It is also flexible with sampling rate and pixel throughput while maintaining the core circuit topology intact. Noise characterization of the IDSAC CDS signal chain has been performed by analytical modelling and practical measurements. Various types of noise such as white, pink, power supply, bias etc. has been considered while creating an analytical noise model tool to predict noise of a controller

  7. A single-pixel optical-sectioning programmable array microscope (SP-PAM)

    Science.gov (United States)

    Wu, Y.; Ye, P.; Arce, G. R.; Prather, D. W.

    2010-02-01

    Programmable array microscopes (PAMs) use "multi-pinhole" masks in confocal image planes to introduce illumination and block the "out-of-focus light". Compared to traditional confocal microscopes (CM), PAM systems have higher efficiency in utilizing the signal light and faster image acquisition speed. However, these advantages are gained at the cost of using more complicated optics and detectors. Compressive sampling (CS) measurement patterns can be used as pinhole masks in PAM systems. With CS patterns, the light collected after the detector mask can be summed up and used to reconstruct the imaging scene via solving an l1-minimization problem. Only a simple relay-lens and a singlepixel detector are needed to measure the intensity of the summed light. Therefore the optical complexity associated with conventional PAM systems can be reduced. Since only a single-pixel detector is needed, this system can also be called a single-pixel PAM or SP-PAM system. In this work, we introduce the design and fabrication of a prototype SP-PAM system. In this system, scrambled-block Hadamard ensembles (SBHE) are used as CS measurement patterns and a digital micromirror device (DMD) is employed to realize these patterns.

  8. Characterization of novel Hamamatsu Multi Pixel Photon Counter (MPPC) arrays for the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Orlando [Universidad T?cnica Federico Santa Mar?a; Rojas, Rimsky [Universidad T?cnica Federico Santa Mar?a; Kuleshov, Sergey V. [Universidad T?cnica Federico Santa Mar?a; Hakobyan, Hayk [Universidad T?cnica Federico Santa Mar?a; Toro, Alam [Universidad T?cnica Federico Santa Mar?a; Brooks, William K. [Universidad T?cnica Federico Santa Mar?a

    2013-12-01

    The novel Hamamatsu Multi Pixel Photon Counter Array S12045(X) is an array of 16 individual MPPCs (3x3 mm{sup 2}) (further in the paper MPPC array channel) each with 3600 G-APD (Geiger-mode Avalanche Photodiodes) pixels (50x50 [{micro}m{sup 2}]). Each MPPC in the array works with its individual reverse bias voltage mode (around 70 V). The paper summarizes the characterization process of MPPC arrays used in GlueX experiment (Hall D, Jefferson Lab). We studied the main features of each MPPC array channel for 2800 MPPC arrays at different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photo detection efficiency (PDE), optical crosstalk and dark rate for each MPPC array channel. The hardware and the data analysis are described, which includes new analytical expressions to obtain the mean number of photo-electrons and optical crosstalk. The dynamical behavior of characterization parameters is presented as well.

  9. Characterization of novel Hamamatsu Multi Pixel Photon Counter (MPPC) arrays for the GlueX experiment

    Science.gov (United States)

    Soto, Orlando; Rojas, Rimsky; Kuleshov, Sergey; Hakobyan, Hayk; Toro, Alam; Brooks, William K.

    2013-12-01

    The novel Hamamatsu Multi Pixel Photon Counter Array S12045(X) is an array of 16 individual MPPCs (3×3 mm2) (further in the paper MPPC array channel) each with 3600 G-APD (Geiger-mode Avalanche Photodiodes) pixels (50×50 [μm2]). Each MPPC in the array works with its individual reverse bias voltage mode (around 70 V). The paper summarizes the characterization process of MPPC arrays used in GlueX experiment (Hall D, Jefferson Lab). We studied the main features of each MPPC array channel for 2800 MPPC arrays at different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photo detection efficiency (PDE), optical crosstalk and dark rate for each MPPC array channel. The hardware and the data analysis are described, which includes new analytical expressions to obtain the mean number of photo-electrons and optical crosstalk. The dynamical behavior of characterization parameters is presented as well.

  10. Characterization of novel Hamamatsu Multi Pixel Photon Counter (MPPC) arrays for the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Orlando, E-mail: oj.5070@gmail.com; Rojas, Rimsky; Kuleshov, Sergey; Hakobyan, Hayk; Toro, Alam; Brooks, William K.

    2013-12-21

    The novel Hamamatsu Multi Pixel Photon Counter Array S12045(X) is an array of 16 individual MPPCs (3×3 mm{sup 2}) (further in the paper MPPC array channel) each with 3600 G-APD (Geiger-mode Avalanche Photodiodes) pixels (50×50 [μm{sup 2}]). Each MPPC in the array works with its individual reverse bias voltage mode (around 70 V). The paper summarizes the characterization process of MPPC arrays used in GlueX experiment (Hall D, Jefferson Lab). We studied the main features of each MPPC array channel for 2800 MPPC arrays at different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photo detection efficiency (PDE), optical crosstalk and dark rate for each MPPC array channel. The hardware and the data analysis are described, which includes new analytical expressions to obtain the mean number of photo-electrons and optical crosstalk. The dynamical behavior of characterization parameters is presented as well.

  11. Recent development of ultra small pixel uncooled focal plane arrays at DRS

    Science.gov (United States)

    Li, Chuan; Skidmore, George D.; Howard, Christopher; Han, C. J.; Wood, Lewis; Peysha, Doug; Williams, Eric; Trujillo, Carlos; Emmett, Jeff; Robas, Gary; Jardine, Daniel; Wan, C.-F.; Clarke, Elwood

    2007-04-01

    DRS is a major supplier of the 25μm pixel pitch 640x480 and 320x240 infrared uncooled focal plane arrays (UFPAs) and camera products for commercial and military markets. The state-of-the-art 25μm pixel focal plane arrays currently in production provide excellent performance for soldier thermal weapon sights (TWS), vehicle driver vision enhancers (DVE), and aerial surveillance and industrial thermograph applications. To further improve sensor resolution and reduce the sensor system size, weight and cost, it is highly desired to reduce the UFPA pixel size. However, the 17μm pixel FPA presents significant design and fabrication challenges as compared with 25μm pixel FPAs. The design objectives, engineering trade-offs, and performance goals will be discussed. This paper presents an overview of the 17μm microblometer uncooled focal plane arrays and sensor electronics production and development activities at DRS. The 17 μm pixel performance data from several initial fabrication lots will be summarized. Relevant 25μm pixel performance data are provided for comparison. Thermal images and video from the 17μm pixel 640x480 UFPA will also be presented.

  12. Alternative Optimizations of X-ray TES Arrays: Soft X-rays, High Count Rates, and Mixed-Pixel Arrays

    Science.gov (United States)

    Kilbourne, C. A.; Bandler, S. R.; Brown, A.-D.; Chervenak, J. A.; Figueroa-Feliciano, E.; Finkbeiner, F. M.; Iyomoto, N.; Kelley, R. L.; Porter, F. S.; Smith, S. J.

    2007-01-01

    We are developing arrays of superconducting transition-edge sensors (TES) for imaging spectroscopy telescopes such as the XMS on Constellation-X. While our primary focus has been on arrays that meet the XMS requirements (of which, foremost, is an energy resolution of 2.5 eV at 6 keV and a bandpass from approx. 0.3 keV to 12 keV), we have also investigated other optimizations that might be used to extend the XMS capabilities. In one of these optimizations, improved resolution below 1 keV is achieved by reducing the heat capacity. Such pixels can be based on our XMS-style TES's with the separate absorbers omitted. These pixels can added to an array with broadband response either as a separate array or interspersed, depending on other factors that include telescope design and science requirements. In one version of this approach, we have designed and fabricated a composite array of low-energy and broad-band pixels to provide high spectral resolving power over a broader energy bandpass than could be obtained with a single TES design. The array consists of alternating pixels with and without overhanging absorbers. To explore optimizations for higher count rates, we are also optimizing the design and operating temperature of pixels that are coupled to a solid substrate. We will present the performance of these variations and discuss other optimizations that could be used to enhance the XMS or enable other astrophysics experiments.

  13. Digital Array Gas Radiometer (DAGR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The digital array gas radiometer (DAGR) is a new sensor design for accurate measurement and monitoring of trace gases in the boundary layer from space, aircraft, or...

  14. Digital Array Gas Radiometer (DAGR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is a digital array gas radiometer (DAGR), a new design for a gas filter correlation radiometer (GFCR) to accurately measure and monitor...

  15. Modelling and 3D optimisation of CdTe pixels detector array geometry - Extension to small pixels

    CERN Document Server

    Zumbiehl, A; Fougeres, P; Koebel, J M; Regal, R; Rit, C; Ayoub, M; Siffert, P

    2001-01-01

    CdTe and CdZnTe pixel detectors offer great interest for many applications, especially for medical and industrial imaging. Up to now, the material, generally, used and investigated for pixel arrays was CZT (Hamel et al., IEEE Trans. Nucl. Sci. 43 (3) (1996) 1422; Barrett et al., Phys. Rev. Lett. 75 (1) (1995) 156; Bennett et al., Nucl. Instr. and Meth. A 392 (1997) 260; Eskin et al., J. Appl. Phys. 85 (2) (1999) 647; Brunett et al., J. Appl. Phys. 86 (7) (1999) 3926; Luke, Nucl. Instr. and Meth. A 380 (1996) 232), but cadmium telluride can also be an appropriate choice, as shown here. However, we clearly demonstrate here that the optimal pixel configuration is highly dependent on the electrical transport properties of the material. Depending on the field of primary interest, either energy resolution or counting rate efficiency in the photopeak, the geometry for each case has to be optimised. For that purpose, we have developed a calculation of the signal induced onto the pixel. Two distinct parts are used: af...

  16. Pixel parallel localized driver design for a 128 x 256 pixel array 3D 1Gfps image sensor

    Science.gov (United States)

    Zhang, C.; Dao, V. T. S.; Etoh, T. G.; Charbon, E.

    2017-02-01

    In this paper, a 3D 1Gfps BSI image sensor is proposed, where 128 × 256 pixels are located in the top-tier chip and a 32 × 32 localized driver array in the bottom-tier chip. Pixels are designed with Multiple Collection Gates (MCG), which collects photons selectively with different collection gates being active at intervals of 1ns to achieve 1Gfps. For the drivers, a global PLL is designed, which consists of a ring oscillator with 6-stage current starved differential inverters, achieving a wide frequency tuning range from 40MHz to 360MHz (20ps rms jitter). The drivers are the replicas of the ring oscillator that operates within a PLL. Together with level shifters and XNOR gates, continuous 3.3V pulses are generated with desired pulse width, which is 1/12 of the PLL clock period. The driver array is activated by a START signal, which propagates through a highly balanced clock tree, to activate all the pixels at the same time with virtually negligible skew.

  17. A near-infrared 64-pixel superconducting nanowire single photon detector array with integrated multiplexed readout

    Energy Technology Data Exchange (ETDEWEB)

    Allman, M. S., E-mail: shane.allman@boulder.nist.gov; Verma, V. B.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Mirin, R.; Nam, S. W. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3328 (United States); Marsili, F.; Beyer, A.; Shaw, M. D. [Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, California 91109 (United States); Kumor, D. [Purdue University, 610 Purdue Mall, West Lafayette, Indiana 47907 (United States)

    2015-05-11

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array as well as characterization measurements are discussed.

  18. A Near-Infrared 64-pixel Superconducting Nanowire Single Photon Detector Array with Integrated Multiplexed Readout

    CERN Document Server

    Allman, M S; Stevens, M; Gerrits, T; Horansky, R D; Lita, A E; Marsili, F; Beyer, A; Shaw, M D; Kumor, D; Mirin, R; Nam, S W

    2015-01-01

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array, as well as characterization measurements are discussed.

  19. Performance Analysis of Digital loudspeaker Arrays

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Kontomichos, Fotios; Mourjopoulos, John

    2008-01-01

    An analysis of digital loudspeaker arrays shows that the ways in which bits are mapped to the drivers influence the quality of the audio result. Specifically, a "bit-summed" rather than the traditional "bit-mapped" strategy greatly reduces the number of times drivers make binary transitions per...... period of the input frequency. Detailed simulations compare the results for a 32-loudspeaker array with a similar configuration with analog excitation of the drivers. Ideally, drivers in digital arrays should be very small and span a small area, but that sets limits on the low-frequency response...

  20. SUB PIXEL IMAGE PROCESSING FOR DISTANCE MEASUREMENT ON THE BASE OF DIGITAL CAMERA

    Directory of Open Access Journals (Sweden)

    V. L. Kozlov

    2012-01-01

    Full Text Available The technique of sub pixel processing of the digital photographic images for precision distances and sizes measurements based on stereogram processing is offered. Experimental results of measuring equipment are presented.

  1. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  2. Pixel-level Analog-To-Digital Converters for Hybrid Pixel Detectors with energy sensitivity

    NARCIS (Netherlands)

    San Segundo Bello, David; Nauta, Bram; Visschers, Jan

    2000-01-01

    Single-photon counting hybrid pixel detectors have shown to be a valid alternative to other types of X-ray imaging devices due to their high sensitivity, low noise, linear behavior and wide dynamic range. One important advantage of these devices is the fact that detector and readout electronics are

  3. High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy.

    Science.gov (United States)

    Tate, Mark W; Purohit, Prafull; Chamberlain, Darol; Nguyen, Kayla X; Hovden, Robert; Chang, Celesta S; Deb, Pratiti; Turgut, Emrah; Heron, John T; Schlom, Darrell G; Ralph, Daniel C; Fuchs, Gregory D; Shanks, Katherine S; Philipp, Hugh T; Muller, David A; Gruner, Sol M

    2016-02-01

    We describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500 µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80-200 keV electron beams.

  4. High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy

    CERN Document Server

    Tate, Mark W; Chamberlain, Darol; Nguyen, Kayla X; Hovden, Robert M; Chang, Celesta S; Deb, Pratiti; Turgut, Emrah; Heron, John T; Schlom, Darrell G; Ralph, Daniel C; Fuchs, Gregory D; Shanks, Katherine S; Philipp, Hugh T; Muller, David A; Gruner, Sol M

    2015-01-01

    We describe a hybrid pixel array detector (EMPAD - electron microscope pixel array detector) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128 x 128 pixel detector consists of a 500 um thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit (ASIC). The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as loc...

  5. Readout of a 176 pixel FDM system for SAFARI TES arrays

    Science.gov (United States)

    Hijmering, R. A.; den Hartog, R.; Ridder, M.; van der Linden, A. J.; van der Kuur, J.; Gao, J. R.; Jackson, B.

    2016-07-01

    In this paper we present the results of our 176-pixel prototype of the FDM readout system for SAFARI, a TES-based focal-plane instrument for the far-IR SPICA mission. We have implemented the knowledge obtained from the detailed study on electrical crosstalk reported previously. The effect of carrier leakage is reduced by a factor two, mutual impedance is reduced to below 1 nH and mutual inductance is removed. The pixels are connected in stages, one quarter of the array half of the array and the full array, to resolve intermediate technical issues. A semi-automated procedure was incorporated to find all optimal settings for all pixels. And as a final step the complete array has been connected and 132 pixels have been read out simultaneously within the frequency range of 1-3.8MHz with an average frequency separation of 16kHz. The noise was found to be detector limited and was not affected by reading out all pixels in a FDM mode. With this result the concept of using FDM for multiplexed bolometer read out for the SAFARI instrument has been demonstrated.

  6. Standard guide for digital detector array radiology

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This standard is a user guide, which is intended to serve as a tutorial for selection and use of various digital detector array systems nominally composed of the detector array and an imaging system to perform digital radiography. This guide also serves as an in-detail reference for the following standards: Practices E2597, , and E2737. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  7. Evaluation of a SiPM array detector coupled to a LFS-3 pixellated scintillator for PET/MR applications

    Energy Technology Data Exchange (ETDEWEB)

    David, Stratos; Fysikopoulos, Eleftherios [Technological Educational Institute of Athens (Greece); Georgiou, Maria [Technological Educational Institute of Athens (Greece); Department of Medical School, University of Thessaly, Larissa (Greece); Loudos, George [Technological Educational Institute of Athens (Greece)

    2015-05-18

    SiPM arrays are insensitive to magnetic fields and thus good candidates for hybrid PET/MR imaging systems. Moreover, due to their small size and flexibility can be used in dedicated small field of view small animal imaging detectors and especially in head PET/MR studies in mice. Co-doped LFS-3 scintillator crystals have higher light yield and slightly faster response than that of LSO:Ce mainly due to the co-doped activation of emission centers with varying materials such as Ce, Gd, Sc, Y, La, Tb, or Ca distributed at the molecular scale through the lutetium silicate crystal host. The purpose of this study is to investigate the behavior of the SensL ArraySL-4 (4x4 element array of 3x3 mm{sup 2} silicon photomultipliers) optical detector coupled to a 6x6 LFS-3 scintillator array, with 2x2x5 mm{sup 3} crystal size elements, for possible applications in small field of view PET/MR imaging detectors. We have designed a symmetric resistive charge division circuit to read out the signal outputs of 4x4 pixel SiPM array reducing the 16 pixel outputs of the photodetector to 4 position signals. The 4 position signals were digitized using free running Analog to Digital Converters. The ADCs sampling rate was 50 MHz. An FPGA (Spartan 6 LX150T) was used for triggering and digital signal processing of the pulses. Experimental evaluation was carried out with {sup 22}Na radioactive source and the parameters studied where energy resolution and peak to valley ratio. The first preliminary results of the evaluation shows a clear visualization of the discrete 2x2x5 mm{sup 3} LFS-3 scintillator elements. The mean peak to valley ratio of the horizontal profiles on the raw image was measured equal to 11 while the energy resolution was calculated equal to 30% at the central pixels.

  8. Theoretical investigation of the noise performance of active pixel imaging arrays based on polycrystalline silicon thin film transistors.

    Science.gov (United States)

    Koniczek, Martin; Antonuk, Larry E; El-Mohri, Youcef; Liang, Albert K; Zhao, Qihua

    2017-07-01

    Active matrix flat-panel imagers, which typically incorporate a pixelated array with one a-Si:H thin-film transistor (TFT) per pixel, have become ubiquitous by virtue of many advantages, including large monolithic construction, radiation tolerance, and high DQE. However, at low exposures such as those encountered in fluoroscopy, digital breast tomosynthesis and breast computed tomography, DQE is degraded due to the modest average signal generated per interacting x-ray relative to electronic additive noise levels of ~1000 e, or greater. A promising strategy for overcoming this limitation is to introduce an amplifier into each pixel, referred to as the active pixel (AP) concept. Such circuits provide in-pixel amplification prior to readout as well as facilitate correlated multiple sampling, enhancing signal-to-noise and restoring DQE at low exposures. In this study, a methodology for theoretically investigating the signal and noise performance of imaging array designs is introduced and applied to the case of AP circuits based on low-temperature polycrystalline silicon (poly-Si), a semiconductor suited to manufacture of large area, radiation tolerant arrays. Computer simulations employing an analog circuit simulator and performed in the temporal domain were used to investigate signal characteristics and major sources of electronic additive noise for various pixel amplifier designs. The noise sources include photodiode shot noise and resistor thermal noise, as well as TFT thermal and flicker noise. TFT signal behavior and flicker noise were parameterized from fits to measurements performed on individual poly-Si test TFTs. The performance of three single-stage and three two-stage pixel amplifier designs were investigated under conditions relevant to fluoroscopy. The study assumes a 20 × 20 cm(2) , 150 μm pitch array operated at 30 fps and coupled to a CsI:Tl x-ray converter. Noise simulations were performed as a function of operating conditions, including

  9. Performance Analysis of Digital loudspeaker Arrays

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Kontomichos, Fotios; Mourjopoulos, John

    2008-01-01

    An analysis of digital loudspeaker arrays shows that the ways in which bits are mapped to the drivers influence the quality of the audio result. Specifically, a "bit-summed" rather than the traditional "bit-mapped" strategy greatly reduces the number of times drivers make binary transitions per p...

  10. Shape determination of microcalcifications in simulated digital mammography images with varying pixel size

    Science.gov (United States)

    Ruschin, Mark; Bath, Magnus; Hemdal, Bengt; Tingberg, Anders

    2005-04-01

    The purpose of this work was to study how the pixel size of digital detectors can affect shape determination of microcalcifications in mammography. Screen-film mammograms containing microcalcifications clinically proven to be indicative of malignancy were digitised at 100 lines/mm using a high-resolution Tango drum scanner. Forty microcalcifications were selected to cover an appropriate range of sizes, shapes and contrasts typically found of malignant cases. Based on the measured MTF and NPS of the combined screen-film and scanner system, these digitised images were filtered to simulate images acquired with a square sampling pixel size of 10 μm x 10 μm and a fill factor of one. To simulate images acquired with larger pixel sizes, these finely sampled images were re-binned to yield a range of effective pixel sizes from 20 μm up to 140 μm. An alternative forced-choice (AFC) observer experiment was conducted with eleven observers for this set of digitised microcalcifications to determine how pixel size affects the ability to discriminate shape. It was found that observer score increased with decreasing pixel size down to 60 μm (p<0.01), at which point no significant advantage was obtained by using smaller pixel sizes due to the excessive relative noise-per-pixel. The relative gain in shape discrimination ability at smaller pixel sizes was larger for microcalcifications that were smaller than 500 μm and circular.

  11. High-speed X-ray imaging pixel array detector for synchrotron bunch isolation

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Hugh T., E-mail: htp2@cornell.edu; Tate, Mark W.; Purohit, Prafull; Shanks, Katherine S.; Weiss, Joel T. [Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M. [Cornell University, Ithaca, NY 14853 (United States); Cornell University, Ithaca, NY 14853 (United States)

    2016-01-28

    A high-speed pixel array detector for time-resolved X-ray imaging at synchrotrons has been developed. The ability to isolate single synchrotron bunches makes it ideal for time-resolved dynamical studies. A wide-dynamic-range imaging X-ray detector designed for recording successive frames at rates up to 10 MHz is described. X-ray imaging with frame rates of up to 6.5 MHz have been experimentally verified. The pixel design allows for up to 8–12 frames to be stored internally at high speed before readout, which occurs at a 1 kHz frame rate. An additional mode of operation allows the integration capacitors to be re-addressed repeatedly before readout which can enhance the signal-to-noise ratio of cyclical processes. This detector, along with modern storage ring sources which provide short (10–100 ps) and intense X-ray pulses at megahertz rates, opens new avenues for the study of rapid structural changes in materials. The detector consists of hybridized modules, each of which is comprised of a 500 µm-thick silicon X-ray sensor solder bump-bonded, pixel by pixel, to an application-specific integrated circuit. The format of each module is 128 × 128 pixels with a pixel pitch of 150 µm. In the prototype detector described here, the three-side buttable modules are tiled in a 3 × 2 array with a full format of 256 × 384 pixels. The characteristics, operation, testing and application of the detector are detailed.

  12. The high dynamic range pixel array detector (HDR-PAD): Concept and design

    Energy Technology Data Exchange (ETDEWEB)

    Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.; Becker, Julian; Tate, Mark W. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M., E-mail: smg26@cornell.edu [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

    2016-07-27

    Experiments at storage ring light sources as well as at next-generation light sources increasingly require detectors capable of high dynamic range operation, combining low-noise detection of single photons with large pixel well depth. XFEL sources in particular provide pulse intensities sufficiently high that a purely photon-counting approach is impractical. The High Dynamic Range Pixel Array Detector (HDR-PAD) project aims to provide a dynamic range extending from single-photon sensitivity to 10{sup 6} photons/pixel in a single XFEL pulse while maintaining the ability to tolerate a sustained flux of 10{sup 11} ph/s/pixel at a storage ring source. Achieving these goals involves the development of fast pixel front-end electronics as well as, in the XFEL case, leveraging the delayed charge collection due to plasma effects in the sensor. A first prototype of essential electronic components of the HDR-PAD readout ASIC, exploring different options for the pixel front-end, has been fabricated. Here, the HDR-PAD concept and preliminary design will be described.

  13. Digital image restoration based on pixel simultaneous detection probabilities

    CERN Document Server

    Grabskii, V

    2008-01-01

    Here an image restoration on the basis of pixel simultaneous detection probabilities (PSDP) is proposed. These probabilities can be precisely determined by means of correlations measurement [NIMA 586 (2008) 314-326]. The proposed image restoration is based on the solution of matrix equation. Non-zero elements of Toeplitz block matrix with ones on the main diagonal, is determined using PSDP. The number of non zero descending diagonals depends on the detector construction and is not always smaller than 8. To solve the matrix equation, the Gaussian elimination algorithm is used. The proposed restoration algorithm is studied by means of the simulated images (with and without additive noise using PSDP for General Electric Senographe 2000D mammography device detector) and a small area (160x160 pixels) of real images acquired by the above mentioned device. The estimation errors of PSDP and the additive noise magnitude permits to restore images with the precision better than 2% for the above mentioned detector. The a...

  14. Experiment on digital CDS with 33-M pixel 120-fps super hi-vision image sensor

    Science.gov (United States)

    Yonai, J.; Yasue, T.; Kitamura, K.; Hayashida, T.; Watabe, T.; Shimamoto, H.; Kawahito, S.

    2014-03-01

    We have developed a CMOS image sensor with 33 million pixels and 120 frames per second (fps) for Super Hi-Vision (SHV:8K version of UHDTV). There is a way to reduce the fixed pattern noise (FPN) caused in CMOS image sensors by using digital correlated double sampling (digital CDS), but digital CDS methods need high-speed analog-to-digital conversion and are not applicable to conventional UHDTV image sensors due to their speed limit. Our image sensor, on the other hand, has a very fast analog-to-digital converter (ADC) using "two-stage cyclic ADC" architecture that is capable of being driven at 120-fps, which is double the normal frame rate for TV. In this experiment, we performed experimental digital CDS using the high-frame rate UHDTV image sensor. By reading the same row twice at 120-fps and subtracting dark pixel signals from accumulated pixel signals, we obtained a 60-fps equivalent video signal with digital noise reduction. The results showed that the VFPN was effectively reduced from 24.25 e-rms to 0.43 e-rms.

  15. Low-Light Image Enhancement Using Adaptive Digital Pixel Binning

    Directory of Open Access Journals (Sweden)

    Yoonjong Yoo

    2015-06-01

    Full Text Available This paper presents an image enhancement algorithm for low-light scenes in an environment with insufficient illumination. Simple amplification of intensity exhibits various undesired artifacts: noise amplification, intensity saturation, and loss of resolution. In order to enhance low-light images without undesired artifacts, a novel digital binning algorithm is proposed that considers brightness, context, noise level, and anti-saturation of a local region in the image. The proposed algorithm does not require any modification of the image sensor or additional frame-memory; it needs only two line-memories in the image signal processor (ISP. Since the proposed algorithm does not use an iterative computation, it can be easily embedded in an existing digital camera ISP pipeline containing a high-resolution image sensor.

  16. 320×240 Pixels CMOS Digital Image Sensor with Wide Dynamic Range

    Institute of Scientific and Technical Information of China (English)

    FANG Jie; WANG Jing-guang; HONG Zhi-liang

    2004-01-01

    A 320×240 CMOS image sensor is demonstrated,which is implemented by a standard 0.6 μm 2P2M CMOS process.For reducing the chip area,each 2×2-pixel block shares a sample/hold circuit,analog-to-digital converter and 1-b memory.The 2×2 pixel pitch has an area of 40 μm×40 μm and the fill factor is about 16%.While operating at a low frame rate,the sensor dissipates a very low power by power-management circuit making pixel-level comparators in an idle state.A digital correlated double sampling,which eliminates fixed pattern noise,improves SNR of the sensor, and multiple sampling operations make the sensor have a wide dynamic range.

  17. Digital column readout architecture for the ATLAS pixel 025 mum front end IC

    CERN Document Server

    Mandelli, E; Blanquart, L; Comes, G; Denes, P; Einsweiler, Kevin F; Fischer, P; Marchesini, R; Meddeler, G; Peric, I

    2002-01-01

    A fast low noise, limited power, radiation-hard front-end chip was developed for reading out the Atlas Pixel Silicon Detector. As in the past prototypes, every chip is used to digitize and read out charge and time information from hits on each one of its 2880 inputs. The basic column readout architecture idea was adopted and modified to allow a safe transition to quarter micron technology. Each pixel cell, organized in a 160 multiplied by 18 matrix, can be independently enabled and configured in order to optimize the analog signal response and to prevent defective pixels from saturating the readout. The digital readout organizes hit data coming from each column, with respect to time, and output them on a low-level serial interface. A considerable effort was made to design state machines free of undefined states, where single-point defects and charge deposited by heavy ions in the silicon could have led to unpredicted forbidden states. 7 Refs.

  18. Study of performance of small gamma camera consisting of crystal pixel array and position sensitive photomultiplier tube

    Institute of Scientific and Technical Information of China (English)

    ZHU Jie; LIU Shi-Tao; LEI Xiao-Wen; YAN Tian-Xin; XU Zi-Zong; WANG Zhao-Min

    2005-01-01

    The performance of gamma camera with NaI(T1) array coupled with position sensitive photomultiplier tube (PSPMT) R2486 has been studied. The pixel size of NaI(T1) crystal is 2mm×2mm and the overall dimension of the array is 48.2mm×48.2mm×5mm. There are 484 pixels in a 22×22 matrix. Because each pixel can produce a much focused light spot and restrict the spread of photons, position resolution of the gamma camera is mainly determined by pixel size. It is shown that crystal array pixel can reduce shrinkage effect and improve intrinsic position resolution greatly via restricting the spread of photons. Experimental results demonstrate that its position resolution and linearity are much improved comparing with the gamma camera using planar crystals coupled with PSPMT.

  19. Comparison of three resistor network division circuits for the readout of 4×4 pixel SiPM arrays

    Energy Technology Data Exchange (ETDEWEB)

    Stratos, David [Department of Medical Instruments Technology, Technological Educational Institute of Athens (Greece); Maria, Georgiou [Department of Medical Instruments Technology, Technological Educational Institute of Athens (Greece); Department of Nuclear Medicine, Medical School, University of Thessaly (Greece); Eleftherios, Fysikopoulos [Department of Medical Instruments Technology, Technological Educational Institute of Athens (Greece); School of Electrical and Computer Engineering, National Technical University of Athens, Athens (Greece); George, Loudos, E-mail: gloudos@teiath.gr [Department of Medical Instruments Technology, Technological Educational Institute of Athens (Greece)

    2013-02-21

    The purpose of this study is to investigate the behavior of a flexible SensL's silicon photomultiplier array (SPMArray4) photodetector for possible applications in PET imaging. We have designed and evaluated three different resistor network division circuits to read out the signal outputs of a 4×4 pixel SiPM array. We have applied firstly (i) a symmetric resistive voltage division circuit, secondly (ii) a symmetric resistive charge division circuit and thirdly (iii) a charge division multiplexing resistor network reducing the 16 pixel outputs to 4 position signals. In the first circuit the SensL SPMArray4-A0 preamplification electronics and a SPMArray4-A1 evaluation board providing the 16 pixels voltage outputs were used, before the symmetric resistive voltage network. We reduced the 16 voltage signals firstly to 4X and 4Y coordinate signals. Then those signals were further reduced to 2X and 2Y position signals connected via a resistor network. In the second readout circuit we have used the same technique but without the preamplification stage. The third circuit is based on a discretized positioning circuit, which multiplexes the 16 signals from the SiPM array to 4 position signals. The 4 position signals (Xa, Xb, Yc and Yd) were digitized using a free running sampling technique. An FPGA (Spartan 6 LX16) was used for triggering and signal processing of the pulses. We acquired raw images and energy histograms of a BGO and a CsI:Na pixilated scintillator under {sup 22}Na excitation. A clear visualization of the discrete 2×2×5 mm{sup 3} pixilated BGO scintillator elements as well as the 1×1×5 mm{sup 3} pixilated CsI:Na crystal array was achieved with all applied readout circuits. The symmetric resistive charge division circuit provides higher peak to valley ratio than the other readout circuits. Τhe sensitivity and the energy resolution remained almost constant for the three circuits.

  20. Versatile, reprogrammable area pixel array detector for time-resolved synchrotron x-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    Gruner, Sol [Cornell Univ., Ithaca, NY (United States)

    2010-05-01

    The final technical report for DOE grant DE-SC0004079 is presented. The goal of the grant was to perform research, development and application of novel imaging x-ray detectors so as to effectively utilize the high intensity and brightness of the national synchrotron radiation facilities to enable previously unfeasible time-resolved x-ray research. The report summarizes the development of the resultant imaging x-ray detectors. Two types of detector platforms were developed: The first is a detector platform (called a Mixed-Mode Pixel Array Detector, or MM-PAD) that can image continuously at over a thousand images per second while maintaining high efficiency for wide dynamic range signals ranging from 1 to hundreds of millions of x-rays per pixel per image. Research on an even higher dynamic range variant is also described. The second detector platform (called the Keck Pixel Array Detector) is capable of acquiring a burst of x-ray images at a rate of millions of images per second.

  1. Optoelectronic multiplexer for digital data processing based on lipid crystal pixels and optical fiber elements

    Science.gov (United States)

    Pérez, I.; Pena, J. M. S.; Torres, J. C.; Manzanares, R.; Marcos, C.; Vázquez, C.

    2007-06-01

    In this work, we present an optoelectronic digital multiplexer 4:1 based on a multipixel nematic liquid crystal cell. This device uses two optical control signals to select one among four possible optical data inputs. These data signals are generated by four red LEDs, which are guided through plastic optical fiber towards liquid crystal pixels. For our purpose, only four pixels of the cell will be used to modulate the optical signal across them. Each pixel will be addressed by a square waveform coming from the conditioning circuit managed by a microcontroller system. The electronic control allows the multiplexer to work as as simple two input logical gates such as AND, NAND, OR, NOR, XOR and XNOR. The operation time of the device is limited by the response time of LC cell that is in the millisecond range.

  2. Comparative study of a wireless digital system and 2 PSP digital systems on proximal caries detection and pixel values.

    Science.gov (United States)

    dos Anjos Pontual, Andrea; de Melo, Daniela Pita; Pontual, Maria Luiza dos Anjos; de Almeida, Solange Maria; Haiter-Neto, Francisco

    2013-01-01

    This study compared the radiographic image quality of 2 photostimulable phosphor (PSP) plate systems with a radiographic system against a complementary metal oxide silicon (CMOS) system. Using the 3 digital systems, 160 approximal surfaces were radiographed under standardized conditions. Using a 5-point scale, 6 observers scored the resulting images for the presence of caries. The presence of caries was validated histologically, and the image receptors were evaluated using receiver operating characteristic curve analysis. The digital systems were used to take radiographs of an aluminum step wedge for objective analysis with pixel density measurements. The mean pixel values were analyzed statistically using the Kruskal-Wallis test and Dunn multiple comparison test (P system was comparable to the PSP plate systems and radiographic film.

  3. On the Performance of Classification Techniques with Pixel Removal Applied to Digit Recognition

    Directory of Open Access Journals (Sweden)

    Jozette V. Roberts

    2016-08-01

    Full Text Available The successive loss of the outermost pixel values or frames in the digital representation of handwritten digits is postulated to have an increasing impact on the degree of accuracy of categorizations of these digits. This removal of frames is referred to as trimming. The first few frames do not contain significant amounts of information and the impact on accuracy should be negligible. As more frames are trimmed, the impact becomes more significant on the ability of each classification model to correctly identify digits. This study focuses on the effects of the trimming of frames of pixels, on the ability of the Recursive Partitioning and Classification Trees method, the Naive Bayes method, the k-Nearest Neighbor method and the Support Vector Machine method in the categorization of handwritten digits. The results from the application of the k-Nearest Neighbour and Recursive Partitioning and Classification Trees methods exemplified the white noise effect in the trimming of the first few frames whilst the Naive Bayes and the Support Vector Machine did not. With respect to time all models saw a relative decrease in time from the initial dataset. The k-Nearest Neighbour method had the greatest decreases whilst the Support Vector Machine had significantly fluctuating times.

  4. 64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detection

    CERN Document Server

    Miki, Shigehito; Wang, Zhen; Terai, Hirotaka

    2014-01-01

    We present the characterization of two-dimensionally arranged 64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detection. NbTiN films deposited on thermally oxidized Si substrates enabled the high-yield production of high-quality SSPD pixels, and all 64 SSPD pixels showed uniform superconducting characteristics. Furthermore, all of the pixels showed single-photon sensitivity, and 60 of the 64 pixels showed a pulse generation probability higher than 90% after photon absorption. As a result of light irradiation from the single-mode optical fiber at different distances between the fiber tip and the active area, the variations of system detection efficiency in each pixel showed reasonable Gaussian distribution to represent the spatial distributions of photon flux intensity.

  5. Aria de pixel: riprodutibilità aurática digitale Ar de pixel: reprodutibilidade aurática digital Pixel air: digital auratic reprodutibility

    Directory of Open Access Journals (Sweden)

    Mássimo Canevacci

    2010-04-01

    Full Text Available Il saggio parte dalla riflessione del testo Writing Culture di Clifford-Marcus. Dopo più di 20 anni, è possibile verificare come questa critica, anziché aprire verso il futuro, ha chiuso una fase della mono-scrittura etnografica basata sul concetto di retorica e autorità. Già nella metà degli anni '80 stavano nascendo forme compositive multi-linguistiche sperimentali che applicavano una "etnografia indisciplinata" a design, architettura, pubblicità, musica, cinema, web. Si apre la sfida per una università non solo basata su Facoltà territoriali. Diverse modalità di comunicare attraverso il digitale mescolano e sincretizzano le visioni dualistiche di Benjamin su aura e riproducibilità. La mia prospettiva finale è la riproducibilità auratica digitale.Este artigo parte da reflexão sobre o texto Culture de.i Clifford-Marcus. Após 20 anos de sua publicação, é possível verificar como a crítica feita por este autor fecou uma fase da mono-escritura etnográfica baseana no conceito de retórica e autoridade. Já na metade dos anos 80 estavam nascendo formas compositivas multi-linguísticas experimentais que aplicavam um "etnografia indisciplinada" ao design, arquitetura, publicidade, música, cinema, web, abrindo uma via para universidades não somente baseadas sobre faculdades territoriais. Diversas modalidades de comunicação são digitalmente mixadas, sincretizando o dualimsno de Benjamin sobre aura e repordutibilidade. A minha perspectiva final é a reprodutibilidade aurática digital.My essay starts from a reflection on Clifford-Marcus's Writing Culture. After more than 20 years, it is possible to verify that such a critique - instead of opening toward the future - was going to close to the traditional ethnographic writing based on rhetoric and authority. In the middle of the 80's, were spreading experimental compositive patterns, applying an "undisciplined ethnography" to design, architecture, advertising, music, cinema and web

  6. A microelectromechanical system digital 3C array seismic cone penetrometer

    NARCIS (Netherlands)

    Ghose, R.

    2012-01-01

    A digital 3C array seismic cone penetrometer has been developed for multidisciplinary geophysical and geotechnical applications. Seven digital triaxial microelectromechanical system accelerometers are installed at 0.25-m intervals to make a 1.5-m-long downhole seismic array. The accelerometers have

  7. A Medipix2-based imaging system for digital mammography with silicon pixel detectors

    CERN Document Server

    Bisogni, M G; Fantacci, M E; Mettivier, G; Montesi, M C; Novelli, M; Quattrocchi, M; Rosso, V; Russo, P; Stefanini, A

    2004-01-01

    In this paper we present the first tests of a digital imaging system based on a silicon pixel detector bump-bonded to an integrated circuit operating in single photon counting mode. The X-rays sensor is a 300 mu m thick silicon, 14 by 14 mm/sup 2/, upon which a matrix of 256 * 256 pixels has been built. The read-out chip, named MEDIPIX2, has been developed at CERN within the MEDIPIX2 Collaboration and it is composed by a matrix of 256 * 256 cells, 55 * 55 mu m/sup 2/. The spatial resolution properties of the system have been assessed by measuring the square wave resolution function (SWRF) and first images of a standard mammographic phantom were acquired using a radiographic tube in the clinical irradiation condition. (5 refs).

  8. LCD panel characterization by measuring full Jones matrix of individual pixels using polarization-sensitive digital holographic microscopy.

    Science.gov (United States)

    Park, Jongchan; Yu, Hyeonseung; Park, Jung-Hoon; Park, YongKeun

    2014-10-06

    We present measurements of the full Jones matrix of individual pixels in a liquid-crystal display (LCD) panel. Employing a polarization-sensitive digital holographic microscopy based on Mach-Zehnder interferometry, the complex amplitudes of the light passing through individual LCD pixels are precisely measured with respect to orthogonal bases of polarization states, from which the full Jones matrix components of individual pixels are obtained. We also measure the changes in the Jones matrix of individual LCD pixels with respect to an applied bias. In addition, the complex optical responses of a LCD panel with respect to arbitrary polarization states of incident light were characterized from the measured Jones matrix.

  9. Integrated X-ray and charged particle active pixel CMOS sensor arrays using an epitaxial silicon sensitive region

    Energy Technology Data Exchange (ETDEWEB)

    Kleinfelder, Stuart; Bichsel, Hans; Bieser, Fred; Matis, Howard S.; Rai, Gulshan; Retiere, Fabrice; Weiman, Howard; Yamamoto, Eugene

    2002-07-01

    Integrated CMOS Active Pixel Sensor (APS) arrays have been fabricated and tested using X-ray and electron sources. The 128 by 128 pixel arrays, designed in a standard 0.25 micron process, use a {approx}10 micron epitaxial silicon layer as a deep detection region. The epitaxial layer has a much greater thickness than the surface features used by standard CMOS APS, leading to stronger signals and potentially better signal-to-noise ratio (SNR). On the other hand, minority carriers confined within the epitaxial region may diffuse to neighboring pixels, blur images and reduce peak signal intensity. But for low-rate, sparse-event images, centroid analysis of this diffusion may be used to increase position resolution. Careful trade-offs involving pixel size and sense-node area verses capacitance must be made to optimize overall performance. The prototype sensor arrays, therefore, include a range of different pixel designs, including different APS circuits and a range of different epitaxial layer contact structures. The fabricated arrays were tested with 1.5 GeV electrons and Fe-55 X-ray sources, yielding a measured noise of 13 electrons RMS and an SNR for single Fe-55 X-rays of greater than 38.

  10. Robustness of Planar Fourier Capture Arrays to Colour Changes and Lost Pixels

    CERN Document Server

    Gill, Patrick R; Sivaramakrishnan, Sriram; Molnar, Alyosha

    2011-01-01

    Planar Fourier capture arrays (PFCAs) are optical sensors built entirely in standard microchip manufacturing flows. PFCAs are composed of ensembles of angle sensitive pixels (ASPs) that each report a single coefficient of the Fourier transform of the far-away scene. Here we characterize the performance of PFCAs under the following three non-optimal conditions. First, we show that PFCAs can operate while sensing light of a wavelength other than the design point. Second, if only a randomly-selected subset of 10% of the ASPs are functional, we can nonetheless reconstruct the entire far-away scene using compressed sensing. Third, if the wavelength of the imaged light is unknown, it can be inferred by demanding self-consistency of the outputs.

  11. Development and operation of a pixel segmented liquid-filled linear array for radiotherapy quality assurance

    Science.gov (United States)

    Pardo, J.; Franco, L.; Gómez, F.; Iglesias, A.; Pazos, A.; Pena, J.; Lobato, R.; Mosquera, J.; Pombar, M.; Sendón, J.

    2005-04-01

    A liquid isooctane (C8H18) filled ionization linear array for radiotherapy quality assurance has been designed, built and tested. The detector consists of 128 pixels, each of them with an area of 1.7 mm × 1.7 mm and a gap of 0.5 mm. The small pixel size makes the detector ideal for high gradient beam profiles such as those present in intensity modulated radiation therapy (IMRT) and radiosurgery. As the read-out electronics we use the X-ray Data Acquisition System with the Xchip developed by the CCLRC. Studies concerning the collection efficiency dependence on the polarization voltage and on the dose rate have been made in order to optimize the device operation. In the first tests, we have studied dose rate and energy dependences. Dose rate dependence was found to be lower than 2.1% up to 5 Gy min-1, and energy dependence lower than 2.5% up to 20 cm depth in solid water. Output factors and penumbras for several rectangular fields have been measured with the linear array and were compared with the results obtained with a 0.125 cm3 air ionization chamber and radiographic film, respectively. Finally, we have acquired profiles for an IMRT field and for a virtual wedge. These profiles have also been compared with radiographic film measurements. All the comparisons show a good correspondence. The device has proved its capability to verify on-line therapy beams with good spatial resolution and signal-to-noise ratio.

  12. Development and operation of a pixel segmented liquid-filled linear array for radiotherapy quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, J [Departamento de Fisica de Particulas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Franco, L [Departamento de Fisica de Particulas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Gomez, F [Departamento de Fisica de Particulas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Iglesias, A [Departamento de Fisica de Particulas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Pazos, A [Departamento de Fisica de Particulas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Pena, J [Departamento de Fisica de Particulas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Lobato, R [Hospital Clinico Universitario de Santiago, Santiago (Spain); Mosquera, J [Hospital Clinico Universitario de Santiago, Santiago (Spain); Pombar, M [Hospital Clinico Universitario de Santiago, Santiago (Spain); Sendon, J [Hospital Clinico Universitario de Santiago, Santiago (Spain)

    2005-04-21

    A liquid isooctane (C{sub 8}H{sub 18}) filled ionization linear array for radiotherapy quality assurance has been designed, built and tested. The detector consists of 128 pixels, each of them with an area of 1.7 mm x 1.7 mm and a gap of 0.5 mm. The small pixel size makes the detector ideal for high gradient beam profiles such as those present in intensity modulated radiation therapy (IMRT) and radiosurgery. As the read-out electronics we use the X-ray Data Acquisition System with the Xchip developed by the CCLRC. Studies concerning the collection efficiency dependence on the polarization voltage and on the dose rate have been made in order to optimize the device operation. In the first tests, we have studied dose rate and energy dependences. Dose rate dependence was found to be lower than 2.1% up to 5 Gy min{sup -1}, and energy dependence lower than 2.5% up to 20 cm depth in solid water. Output factors and penumbras for several rectangular fields have been measured with the linear array and were compared with the results obtained with a 0.125 cm{sup 3} air ionization chamber and radiographic film, respectively. Finally, we have acquired profiles for an IMRT field and for a virtual wedge. These profiles have also been compared with radiographic film measurements. All the comparisons show a good correspondence. The device has proved its capability to verify on-line therapy beams with good spatial resolution and signal-to-noise ratio.

  13. A sub-millimeter resolution PET detector module using a multi-pixel photon counter array.

    Science.gov (United States)

    Song, Tae Yong; Wu, Heyu; Komarov, Sergey; Siegel, Stefan B; Tai, Yuan-Chuan

    2010-05-07

    A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 x 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 x 0.8 x 3 mm(3) and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 x 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and +/-5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when +/-10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing

  14. Reconstruction of the absorption spectrum of an object spot from the colour values of the corresponding pixel(s) in its digital image: the challenge of algal colours.

    Science.gov (United States)

    Coltelli, Primo; Barsanti, Laura; Evangelista, Valter; Frassanito, Anna Maria; Gualtieri, Paolo

    2016-12-01

    A novel procedure for deriving the absorption spectrum of an object spot from the colour values of the corresponding pixel(s) in its image is presented. Any digital image acquired by a microscope can be used; typical applications are the analysis of cellular/subcellular metabolic processes under physiological conditions and in response to environmental stressors (e.g. heavy metals), and the measurement of chromophore composition, distribution and concentration in cells. In this paper, we challenged the procedure with images of algae, acquired by means of a CCD camera mounted onto a microscope. The many colours algae display result from the combinations of chromophores whose spectroscopic information is limited to organic solvents extracts that suffers from displacements, amplifications, and contraction/dilatation respect to spectra recorded inside the cell. Hence, preliminary processing is necessary, which consists of in vivo measurement of the absorption spectra of photosynthetic compartments of algal cells and determination of spectra of the single chromophores inside the cell. The final step of the procedure consists in the reconstruction of the absorption spectrum of the cell spot from the colour values of the corresponding pixel(s) in its digital image by minimization of a system of transcendental equations based on the absorption spectra of the chromophores under physiological conditions.

  15. A versatile digital camera trigger for telescopes in the Cherenkov Telescope Array

    CERN Document Server

    Schwanke, U; Sulanke, K -H; Vorobiov, S; Wischnewski, R

    2015-01-01

    This paper describes the concept of an FPGA-based digital camera trigger for imaging atmospheric Cherenkov telescopes, developed for the future Cherenkov Telescope Array (CTA). The proposed camera trigger is designed to select images initiated by the Cherenkov emission of extended air showers from very-high energy (VHE, E>20 GeV) photons and charged particles while suppressing signatures from background light. The trigger comprises three stages. A first stage employs programmable discriminators to digitize the signals arriving from the camera channels (pixels). At the second stage, a grid of low-cost FPGAs is used to process the digitized signals for camera regions with 37 pixels. At the third stage, trigger conditions found independently in any of the overlapping 37-pixel regions are combined into a global camera trigger by few central FPGAs. Trigger prototype boards based on Xilinx FPGAs have been designed, built and tested and were shown to function properly. Using these components a full camera trigger wi...

  16. High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector

    Energy Technology Data Exchange (ETDEWEB)

    Giewekemeyer, Klaus, E-mail: klaus.giewekemeyer@xfel.eu [European XFEL GmbH, Hamburg (Germany); Philipp, Hugh T. [Cornell University, Ithaca, NY (United States); Wilke, Robin N. [Georg-August-Universität Göttingen, Göttingen (Germany); Aquila, Andrew [European XFEL GmbH, Hamburg (Germany); Osterhoff, Markus [Georg-August-Universität Göttingen, Göttingen (Germany); Tate, Mark W.; Shanks, Katherine S. [Cornell University, Ithaca, NY (United States); Zozulya, Alexey V. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Salditt, Tim [Georg-August-Universität Göttingen, Göttingen (Germany); Gruner, Sol M. [Cornell University, Ithaca, NY (United States); Cornell University, Ithaca, NY (United States); Kavli Institute of Cornell for Nanoscience, Ithaca, NY (United States); Mancuso, Adrian P. [European XFEL GmbH, Hamburg (Germany)

    2014-08-07

    The advantages of a novel wide dynamic range hard X-ray detector are demonstrated for (ptychographic) coherent X-ray diffractive imaging. Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 10{sup 8} 8-keV photons pixel{sup −1} s{sup −1}, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 10{sup 10} photons µm{sup −2} s{sup −1} within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while ‘still’ images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described.

  17. What if the Earth is Not Flat? Cross-Scale Analysis of Sub-Pixel Variations in Digital Elevation Models

    Science.gov (United States)

    Ghandehari, M.; P Buttenfield, B.; J Q Farmer, C.

    2016-12-01

    Digital terrain models guide scientists and planners in multiple ways and have fundamental impacts on society, safety and resource management. Terrain is currently modeled in a grid of pixels, assuming that elevation values are constant within any single pixel of a Digital Elevation Model (DEM) (`rigid pixel' paradigm). The assumption of rigid pixels generates basic spatial measurements that are in fact imprecise. In truth, terrain can bend, twist and undulate within each pixel, more similar to a continuous and flexible fabric. For localized areas or for very small pixel sizes, the amount of imprecision is insignificant, but can increase with larger pixel size and/or across regional or global expanses, as in the case with models of climate change, sea level rise, and other modeling applications, where pixels can span dozens to hundreds of kilometers. This research examines the sensitivity of surface adjustment to a progression of spatial resolutions (10, 30, 100, and 1000 meter DEMs), validating sub-pixel variations that can be directly measured from finer resolution LiDAR data. Tests will interpolate the elevation of 1,000 georeferenced random points using different methods (weighted average, as well as bi-linear, bi-quadratic, and bi-cubic polynomial fitting) and different contiguity configurations (incorporating first and second order neighbors), and conflate each resolution against a finer resolution LiDAR data benchmark. Additional tests will compute Root Mean Square Error (RMSE) between DEM and LiDAR to assess differences in various methods and resolutions. The paper will present results of the benchmark comparison for a number of study areas characterized by varying degrees of terrain roughness, along with guidelines for determining what terrain conditions and spatial resolutions dramatically modify elevation estimates, and which elevation estimation method(s) are more reliable for particular terrain conditions and particular pixel sizes.

  18. Low Power Systolic Array Based Digital Filter for DSP Applications

    Directory of Open Access Journals (Sweden)

    S. Karthick

    2015-01-01

    Full Text Available Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  19. Low Power Systolic Array Based Digital Filter for DSP Applications.

    Science.gov (United States)

    Karthick, S; Valarmathy, S; Prabhu, E

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  20. Tiled Array of Pixelated CZT Imaging Detectors for ProtoEXIST2 and MIRAX-HXI

    CERN Document Server

    Hong, Jaesub; Grindlay, Jonathan; Rodrigues, Barbara; Ellis, Jon Robert; Baker, Robert; Barthelmy, Scott; Mao, Peter; Miyasaka, Hiromasa; Apple, Jeff

    2013-01-01

    We have assembled a tiled array (220 cm2) of fine pixel (0.6 mm) imaging CZT detectors for a balloon borne wide-field hard X-ray telescope, ProtoEXIST2. ProtoEXIST2 is a prototype experiment for a next generation hard X-ray imager MIRAX-HXI on board Lattes, a spacecraft from the Agencia Espacial Brasilieira. MIRAX will survey the 5 to 200 keV sky of Galactic bulge, adjoining southern Galactic plane and the extragalactic sky with 6' angular resolution. This survey will open a vast discovery space in timing studies of accretion neutron stars and black holes. The ProtoEXIST2 CZT detector plane consists of 64 of 5 mm thick 2 cm x 2 cm CZT crystals tiled with a minimal gap. MIRAX will consist of 4 such detector planes, each of which will be imaged with its own coded-aperture mask. We present the packaging architecture and assembly procedure of the ProtoEXIST2 detector. On 2012, Oct 10, we conducted a successful high altitude balloon experiment of the ProtoEXIST1 and 2 telescopes, which demonstrates their technolog...

  1. High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector

    Science.gov (United States)

    Giewekemeyer, Klaus; Philipp, Hugh T.; Wilke, Robin N.; Aquila, Andrew; Osterhoff, Markus; Tate, Mark W.; Shanks, Katherine S.; Zozulya, Alexey V.; Salditt, Tim; Gruner, Sol M.; Mancuso, Adrian P.

    2014-01-01

    Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 108 8-keV photons pixel−1 s−1, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 1010 photons µm−2 s−1 within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while ‘still’ images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described. PMID:25178008

  2. A Sub-pixel Image Processing Algorithm of a Detector Based on Staring Focal Plane Array

    Institute of Scientific and Technical Information of China (English)

    LI Ya-qiong; JIN Wei-qi; XU Chao; WANG Xia

    2008-01-01

    Optical micro-scanning technology can be used to increase spatial resolution of many optical imaging systems, especially thermal imaging system. One of its key issues is relevant image processing algorithm. A fast reconstruction algo-rithm is proposed for two dimensional 2×2 micro-scanning based on the sub-pixel imaging and reconstruction principle of two-dimensional stating focal plane arrays (FPA). Specifically, three initialization methods are presented and implemented with the simulated data, their performances are compared according to image quality index . Experiment results show that, by the first initialization approach, tirnely over-sampled image can be accurately recovered, although special field diaphragm is needed. In the second initialization, the extrapolation approximation in obtaining reconstruction results is better than either bilinear interpolation or over-sampling reconstruction, without requiting any special process on system. The proposed algorithm has simple structure, low computational cost and can be realized in real-time. A high-resolution image can be obtained by low-resolution detectors. So, the algorithm has potential applications in visible light and infrared imaging area.

  3. Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Vassiljev, N; Konstantinidis, A C; Speller, R D; Kanicki, J

    2017-03-07

    High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm(-1)) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

  4. Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

    Science.gov (United States)

    Zhao, C.; Vassiljev, N.; Konstantinidis, A. C.; Speller, R. D.; Kanicki, J.

    2017-03-01

    High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm-1) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

  5. Novel Hamamatsu Multi-Pixel Photon Counter (MPPC) array studies for the GlueX experiment: New results

    Science.gov (United States)

    Soto, Orlando; Rojas, Rimsky; Kuleshov, Sergey; Hakobyan, Hayk; Toro, Alam; Brooks, William K.; Rios, Rene

    2014-03-01

    The novel Hamamatsu Multi-Pixel Photon Counter (MPPC) S12045(X) is an array of 16 individual 3×3 mm2 MPPC devices each with 3600 Geiger-mode Avalanche Photodiode pixels of 50×50 μm2. Each MPPC in the array operates at a reverse bias of approximately 70 V. This paper summarizes our characterization of MPPC arrays used in the GlueX experiment in Hall D at Thomas Jefferson National Accelerator Facility (Jefferson Lab). We studied the main features of each of the 16 MPPC array channels for 2800 MPPC arrays at several different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photon detection efficiency, optical crosstalk and dark rate for each of the 44 800 MPPC array channels at each temperature setting. The hardware and the data analysis are described, and new analytical expressions for the mean number of photoelectrons and optical crosstalk are presented, as well as systematic trends of the performance parameters.

  6. Novel Hamamatsu Multi-Pixel Photon Counter (MPPC) array studies for the GlueX experiment: New results

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Orlando; Rojas, Rimsky; Kuleshov, Sergey; Hakobyan, Hayk, E-mail: hayk.hakobyan@usm.cl; Toro, Alam; Brooks, William K.; Rios, Rene

    2014-03-01

    The novel Hamamatsu Multi-Pixel Photon Counter (MPPC) S12045(X) is an array of 16 individual 3×3 mm{sup 2} MPPC devices each with 3600 Geiger-mode Avalanche Photodiode pixels of 50×50 μm{sup 2}. Each MPPC in the array operates at a reverse bias of approximately 70 V. This paper summarizes our characterization of MPPC arrays used in the GlueX experiment in Hall D at Thomas Jefferson National Accelerator Facility (Jefferson Lab). We studied the main features of each of the 16 MPPC array channels for 2800 MPPC arrays at several different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photon detection efficiency, optical crosstalk and dark rate for each of the 44 800 MPPC array channels at each temperature setting. The hardware and the data analysis are described, and new analytical expressions for the mean number of photoelectrons and optical crosstalk are presented, as well as systematic trends of the performance parameters.

  7. The Pixel Paradox and Transition-Metal Spectroscopy: One of Many Uses of the Handheld Digital Microscope in Chemical Demonstrations

    Science.gov (United States)

    Vitz, Ed

    2010-01-01

    A handheld digital microscope (HDM) interfaced to a computer with a presentation projector is used to project an out-of-focus yellow patch on the screen, then the patch is brought into focus to show that, paradoxically, there are red and green but no yellow pixels. Chromaticity diagrams are used to discuss this observation and spectroscopic…

  8. The Pixel Paradox and Transition-Metal Spectroscopy: One of Many Uses of the Handheld Digital Microscope in Chemical Demonstrations

    Science.gov (United States)

    Vitz, Ed

    2010-01-01

    A handheld digital microscope (HDM) interfaced to a computer with a presentation projector is used to project an out-of-focus yellow patch on the screen, then the patch is brought into focus to show that, paradoxically, there are red and green but no yellow pixels. Chromaticity diagrams are used to discuss this observation and spectroscopic…

  9. 50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Konstantinidis, A C; Zheng, Y; Anaxagoras, T; Speller, R D; Kanicki, J

    2015-12-07

    Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm(-1) and a DQE of around 0.5 at spatial frequencies  CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered.

  10. A 4 X 4 X 416 digital SiPM array with 192 TDCs for multiple high-resolution timestamp acquisition

    NARCIS (Netherlands)

    Mandai, S.; Charbon, E.

    2013-01-01

    We present a 4 X 4 array of digital silicon photomultipliers (D-SiPMs) capable of timestamping up to 48 photons per D-SiPM and we show the advantage of generating multiple timestamps in the context of positron emission tomography (PET). The D-SiPMs have a pitch of 800 μm and comprise 416 pixels

  11. A 4 X 4 X 416 digital SiPM array with 192 TDCs for multiple high-resolution timestamp acquisition

    NARCIS (Netherlands)

    Mandai, S.; Charbon, E.

    2013-01-01

    We present a 4 X 4 array of digital silicon photomultipliers (D-SiPMs) capable of timestamping up to 48 photons per D-SiPM and we show the advantage of generating multiple timestamps in the context of positron emission tomography (PET). The D-SiPMs have a pitch of 800 μm and comprise 416 pixels each

  12. System Realization of Broad Band Digital Beam Forming for Digital Array Radar

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2013-09-01

    Full Text Available Broad band Digital Beam Forming (DBF is the key technique for the realization of Digital Array Radar (DAR. We propose the method of combination realization of the channel equalization and DBF time delay filter function by using adaptive Sample Matrix Inversion algorithm. The broad band DBF function is realized on a new DBF module based on parallel fiber optic engines and Field Program Gate Array (FPGA. Good performance is achieved when it is used to some radar products.

  13. Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, Srinivasan; Shrestha, Suman; Karellas, Andrew, E-mail: andrew.karellas@umassmed.edu; Shi, Linxi; Gounis, Matthew J. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Bellazzini, Ronaldo; Spandre, Gloria; Brez, Alessandro; Minuti, Massimo [Istituto Nazionale di Fisica Nucleare (INFN), Pisa 56127, Italy and Pixirad Imaging Counters s.r.l., L. Pontecorvo 3, Pisa 56127 (Italy)

    2016-05-15

    Purpose: High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector. Methods: A 650 μm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 μm resulting in pixel pitch of 60 and 51.96 μm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 μGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function (MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit. Results: At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54

  14. A Digital-Receiver for the Murchison Widefield Array

    CERN Document Server

    Prabu, Thiagaraj; Roshi, D Anish; Kamini, P A; Madhavi, S; Emrich, David; Crosse, Brian; Williams, Andrew J; Waterson, Mark; Deshpande, Avinash A; Shankar, N Udaya; Subrahmanyan, Ravi; Briggs, Frank H; Goeke, Robert F; Tingay, Steven J; Johnston-Hollitt, Melanie; R, Gopalakrishna M; Morgan, Edward H; Pathikulangara, Joseph; Bunton, John D; Hampson, Grant; Williams, Christopher; Ord, Stephen M; Wayth, Randall B; Kumar, Deepak; Morales, Miguel F; deSouza, Ludi; Kratzenberg, Eric; Pallot, D; McWhirter, Russell; Hazelton, Bryna J; Arcus, Wayne; Barnes, David G; Bernardi, Gianni; Booler, T; Bowman, Judd D; Cappallo, Roger J; Corey, Brian E; Greenhill, Lincoln J; Herne, David; Hewitt, Jacqueline N; Kaplan, David L; Kasper, Justin C; Kincaid, Barton B; Koenig, Ronald; Lonsdale, Colin J; Lynch, Mervyn J; Mitchell, Daniel A; Oberoi, Divya; Remillard, Ronald A; Rogers, Alan E; Salah, Joseph E; Sault, Robert J; Stevens, Jamie B; Tremblay, S E; Webster, Rachel L; Whitney, Alan R; Wyithe, Stuart B

    2015-01-01

    An FPGA-based digital-receiver has been developed for a low-frequency imaging radio interferometer, the Murchison Widefield Array (MWA). The MWA, located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia, consists of 128 dual-polarized aperture-array elements (tiles) operating between 80 and 300\\,MHz, with a total processed bandwidth of 30.72 MHz for each polarization. Radio-frequency signals from the tiles are amplified and band limited using analog signal conditioning units; sampled and channelized by digital-receivers. The signals from eight tiles are processed by a single digital-receiver, thus requiring 16 digital-receivers for the MWA. The main function of the digital-receivers is to digitize the broad-band signals from each tile, channelize them to form the sky-band, and transport it through optical fibers to a centrally located correlator for further processing. The digital-receiver firmware also implements functions to measure the signal power, perform power equalization across ...

  15. GEM400: A front-end chip based on capacitor-switch array for pixel-based GEM detector

    Science.gov (United States)

    Li, H. S.; Jiang, X. S.; Liu, G.; Wang, N.; Sheng, H. Y.; Zhuang, B. A.; Zhao, J. W.

    2012-03-01

    The upgrade of Beijing Synchrotron Radiation Facility (BSRF) needs two-dimensional position-sensitive detection equipment to improve the experimental performance. Gas Electron Multiplier (GEM) detector, in particular, pixel-based GEM detector has good application prospects in the domain of synchrotron radiation. The read-out of larger scale pixel-based GEM detector is difficult for the high density of the pixels (PAD for collecting electrons). In order to reduce the number of cables, this paper presents a read-out scheme for pixel-based GEM detector, which is based on System-in-Package technology and ASIC technology. We proposed a circuit structure based on capacitor switch array circuit, and design a chip GEM400, which is a 400 channels ASIC. The proposed circuit can achieve good stability and low power dissipation. The chip is implemented in a 0.35μm CMOS process. The basic functional circuitry in ths chip includes analog switch, analog buffer, voltage amplifier, bandgap and control logic block, and the layout of this chip takes 5mm × 5mm area. The simulation results show that the chip can allow the maximum amount of input charge 70pC on the condition of 100pF external integrator capacitor. Besides, the chip has good channel uniformity (INL is better than 0.1%) and lower power dissipation.

  16. Piezoelectric array elements for sound reconstruction with a digital input

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-10-13

    Various examples are provided for digital sound reconstruction using piezoelectric array elements. In one example, a digital loudspeaker includes a fixed frame and an array of transducers disposed on the fixed frame. Individual transducers of the array of transducers can include a flexible membrane disposed on a piezoelectric actuation element positioned over a corresponding opening that extends through the fixed frame. In another example, a method includes forming a flexible membrane structure on a substrate and backetching the substrate opposite the flexible membrane structure. The flexible membrane structure can be formed by disposing a first electrode layer on a substrate, disposing a piezoelectric layer on the first electrode layer and disposing a second electrode layer on the piezoelectric layer. A flexible membrane layer (e.g., polyimide) can be disposed on the second electrode layer.

  17. 256-pixel microcalorimeter array for high-resolution γ-ray spectroscopy of mixed-actinide materials

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, R., E-mail: rwinkler@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM (United States); Hoover, A.S.; Rabin, M.W. [Los Alamos National Laboratory, Los Alamos, NM (United States); Bennett, D.A.; Doriese, W.B.; Fowler, J.W.; Hays-Wehle, J.; Horansky, R.D.; Reintsema, C.D.; Schmidt, D.R.; Vale, L.R.; Ullom, J.N. [National Institute of Standards and Technology, Boulder, CO (United States)

    2015-01-11

    The application of cryogenic microcalorimeter detectors to γ-ray spectroscopy allows for measurements with unprecedented energy resolution. These detectors are ideally suited for γ-ray spectroscopy applications for which the measurement quality is limited by the spectral overlap of many closely spaced transitions using conventional detector technologies. The non-destructive analysis of mixed-isotope Pu materials is one such application where the precision can be potentially improved utilizing microcalorimeter detectors compared to current state-of-the-art high-purity Ge detectors (HPGe). The LANL-NIST γ-ray spectrometer, a 256-pixel microcalorimeter array based on transition-edge sensors (TESs), was recently commissioned and used to collect data on a variety of Pu isotopic standards to characterize the instrument performance. These measurements represent the first time the simultaneous readout of all 256 pixels for measurements of mixed-isotope Pu materials has been achieved. The LANL-NIST γ-ray spectrometer has demonstrated an average pixel resolution of 55 eV full-width-at-half-maximum at 100 keV, nearly an order of magnitude better than HPGe detectors. Some challenges of the analysis of many-channel ultra-high resolution data and the techniques used to produce quality spectra for isotopic analysis will be presented. The LANL-NIST γ-ray spectrometer has also demonstrated stable operation and obtained high resolution measurements at total array event rates beyond 1 kHz. For a total event rate of 1.25 kHz, approximately 5.6 cps/pixel, a 72.2 eV average FWHM for the 103 keV photopeak of {sup 153}Gd was achieved.

  18. Advances in Small Pixel TES-Based X-Ray Microcalorimeter Arrays for Solar Physics and Astrophysics

    Science.gov (United States)

    Bandler, S. R.; Adams, J. S.; Bailey, C. N.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; Kilbourne, C. A.; Porst, J.-P.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2012-01-01

    We are developing small-pixel transition-edge-sensor (TES) for solar physics and astrophysics applications. These large format close-packed arrays are fabricated on solid silicon substrates and are designed to accommodate count-rates of up to a few hundred counts/pixel/second at a FWHM energy resolution approximately 2 eV at 6 keV. We have fabricated versions that utilize narrow-line planar and stripline wiring. We present measurements of the performance and uniformity of kilo-pixel arrays, incorporating TESs with single 65-micron absorbers on a 7s-micron pitch, as well as versions with more than one absorber attached to the TES, 4-absorber and 9-absorber "Hydras". We have also fabricated a version of this detector optimized for lower energies and lower count-rate applications. These devices have a lower superconducting transition temperature and are operated just above the 40mK heat sink temperature. This results in a lower heat capacity and low thermal conductance to the heat sink. With individual single pixels of this type we have achieved a FWHM energy resolution of 0.9 eV with 1.5 keV Al K x-rays, to our knowledge the first x-ray microcalorimeter with sub-eV energy resolution. The 4-absorber and 9-absorber versions of this type achieved FWHM energy resolutions of 1.4 eV and 2.1 eV at 1.5 keV respectively. We will discuss the application of these devices for new astrophysics mission concepts.

  19. iPixel: a visual content-based and semantic search engine for retrieving digitized mammograms by using collective intelligence.

    Science.gov (United States)

    Alor-Hernández, Giner; Pérez-Gallardo, Yuliana; Posada-Gómez, Rubén; Cortes-Robles, Guillermo; Rodríguez-González, Alejandro; Aguilar-Laserre, Alberto A

    2012-09-01

    Nowadays, traditional search engines such as Google, Yahoo and Bing facilitate the retrieval of information in the format of images, but the results are not always useful for the users. This is mainly due to two problems: (1) the semantic keywords are not taken into consideration and (2) it is not always possible to establish a query using the image features. This issue has been covered in different domains in order to develop content-based image retrieval (CBIR) systems. The expert community has focussed their attention on the healthcare domain, where a lot of visual information for medical analysis is available. This paper provides a solution called iPixel Visual Search Engine, which involves semantics and content issues in order to search for digitized mammograms. iPixel offers the possibility of retrieving mammogram features using collective intelligence and implementing a CBIR algorithm. Our proposal compares not only features with similar semantic meaning, but also visual features. In this sense, the comparisons are made in different ways: by the number of regions per image, by maximum and minimum size of regions per image and by average intensity level of each region. iPixel Visual Search Engine supports the medical community in differential diagnoses related to the diseases of the breast. The iPixel Visual Search Engine has been validated by experts in the healthcare domain, such as radiologists, in addition to experts in digital image analysis.

  20. NOTE: First images of a digital autoradiography system based on a Medipix2 hybrid silicon pixel detector

    Science.gov (United States)

    Mettivier, Giovanni; Montesi, Maria Cristina; Russo, Paolo

    2003-06-01

    We present the first images of beta autoradiography obtained with the high-resolution hybrid pixel detector consisting of the Medipix2 single photon counting read-out chip bump-bonded to a 300 µm thick silicon pixel detector. This room temperature system has 256 × 256 square pixels of 55 µm pitch (total sensitive area of 14 × 14 mm2), with a double threshold discriminator and a 13-bit counter in each pixel. It is read out via a dedicated electronic interface and control software, also developed in the framework of the European Medipix2 Collaboration. Digital beta autoradiograms of 14C microscale standard strips (containing separate bands of increasing specific activity in the range 0.0038-32.9 kBq g-1) indicate system linearity down to a total background noise of 1.8 × 10-3 counts mm-2 s-1. The minimum detectable activity is estimated to be 0.012 Bq for 36 000 s exposure and 0.023 Bq for 10 800 s exposure. The measured minimum detection threshold is less than 1600 electrons (equivalent to about 6 keV Si). This real-time system for beta autoradiography offers lower pixel pitch and higher sensitive area than the previous Medipix1-based system. It has a 14C sensitivity better than that of micro channel plate based systems, which, however, shows higher spatial resolution and sensitive area.

  1. Characterization of CdTe sensors with Schottky contacts coupled to charge-integrating pixel array detectors for X-ray science

    Science.gov (United States)

    Becker, J.; Tate, M. W.; Shanks, K. S.; Philipp, H. T.; Weiss, J. T.; Purohit, P.; Chamberlain, D.; Ruff, J. P. C.; Gruner, S. M.

    2016-12-01

    Pixel Array Detectors (PADs) consist of an x-ray sensor layer bonded pixel-by-pixel to an underlying readout chip. This approach allows both the sensor and the custom pixel electronics to be tailored independently to best match the x-ray imaging requirements. Here we present characterizations of CdTe sensors hybridized with two different charge-integrating readout chips, the Keck PAD and the Mixed-Mode PAD (MM-PAD), both developed previously in our laboratory. The charge-integrating architecture of each of these PADs extends the instantaneous counting rate by many orders of magnitude beyond that obtainable with photon counting architectures. The Keck PAD chip consists of rapid, 8-frame, in-pixel storage elements with framing periods detector, the MM-PAD, has an extended dynamic range by utilizing an in-pixel overflow counter coupled with charge removal circuitry activated at each overflow. This allows the recording of signals from the single-photon level to tens of millions of x-rays/pixel/frame while framing at 1 kHz. Both detector chips consist of a 128 × 128 pixel array with (150 μm)2 pixels.

  2. High-speed imaging at high x-ray energy: CdTe sensors coupled to charge-integrating pixel array detectors

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Julian; Tate, Mark W.; Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.; Purohit, Prafull [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Chamberlain, Darol [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M., E-mail: smg26@cornell.edu [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

    2016-07-27

    Pixel Array Detectors (PADs) consist of an x-ray sensor layer bonded pixel-by-pixel to an underlying readout chip. This approach allows both the sensor and the custom pixel electronics to be tailored independently to best match the x-ray imaging requirements. Here we describe the hybridization of CdTe sensors to two different charge-integrating readout chips, the Keck PAD and the Mixed-Mode PAD (MM-PAD), both developed previously in our laboratory. The charge-integrating architecture of each of these PADs extends the instantaneous counting rate by many orders of magnitude beyond that obtainable with photon counting architectures. The Keck PAD chip consists of rapid, 8-frame, in-pixel storage elements with framing periods <150 ns. The second detector, the MM-PAD, has an extended dynamic range by utilizing an in-pixel overflow counter coupled with charge removal circuitry activated at each overflow. This allows the recording of signals from the single-photon level to tens of millions of x-rays/pixel/frame while framing at 1 kHz. Both detector chips consist of a 128×128 pixel array with (150 µm){sup 2} pixels.

  3. The application of taylor weighting, digital phase shifters, and digital attenuators to phased-array antennas.

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Billy C.

    2008-03-01

    Application of Taylor weighting (taper) to an antenna aperture can achieve low peak sidelobes, but combining the Taylor weighting with quantized attenuators and phase shifters at each radiating element will impact the performance of a phased-array antenna. An examination of array performance is undertaken from the simple point of view of the characteristics of the array factor. Design rules and guidelines for determining the Taylor-weighting parameters, the number of bits required for the digital phase shifter, and the dynamic range and number of bits required for the digital attenuator are developed. For a radar application, when each element is fed directly from a transmit/receive module, the total power radiated by the array will be reduced as a result of the taper. Consequently, the issue of whether to apply the taper on both transmit and receive configurations, or only on the receive configuration is examined with respect to two-way sidelobe performance.

  4. Transition-edge sensor pixel parameter design of the microcalorimeter array for the x-ray integral field unit on Athena

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Bandler, S. R.; Betancourt-Martinez, G. L.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Miniussi, A. R.; Porter, F. S.; Sadleir, J. E.; Sakai, K.; Wakeham, N. A.; Wassell, E. J.; Yoon, W.; Bennett, D. A.; Doriese, W. B.; Fowler, J. W.; Hilton, G. C.; Morgan, K. M.; Pappas, C. G.; Reintsema, C. N.; Swetz, D. S.; Ullom, J. N.; Irwin, K. D.; Akamatsu, H.; Gottardi, L.; den Hartog, R.; Jackson, B. D.; van der Kuur, J.; Barret, D.; Peille, P.

    2016-07-01

    The focal plane of the X-ray integral field unit (X-IFU) for ESA's Athena X-ray observatory will consist of 4000 transition edge sensor (TES) x-ray microcalorimeters optimized for the energy range of 0.2 to 12 keV. The instrument will provide unprecedented spectral resolution of 2.5 eV at energies of up to 7 keV and will accommodate photon fluxes of 1 mCrab (90 cps) for point source observations. The baseline configuration is a uniform large pixel array (LPA) of 4.28" pixels that is read out using frequency domain multiplexing (FDM). However, an alternative configuration under study incorporates an 18 × 18 small pixel array (SPA) of 2" pixels in the central 36" region. This hybrid array configuration could be designed to accommodate higher fluxes of up to 10 mCrab (900 cps) or alternately for improved spectral performance (report on the TES pixel designs that are being optimized to meet these proposed LPA and SPA configurations. In particular we describe details of how important TES parameters are chosen to meet the specific mission criteria such as energy resolution, count-rate and quantum efficiency, and highlight performance trade-offs between designs. The basis of the pixel parameter selection is discussed in the context of existing TES arrays that are being developed for solar and x-ray astronomy applications. We describe the latest results on DC biased diagnostic arrays as well as large format kilo-pixel arrays and discuss the technical challenges associated with integrating different array types on to a single detector die.

  5. 16k pixel digital line-scan sensor with 12bit resolution and 40kS/second

    Science.gov (United States)

    Wäny, Martin; Franco, Paulo; Voltz, Stephan

    2009-02-01

    This paper presents a digital line-scan sensor in standard CMOS technology for high resolution scanning application in machine vision, mainly surface inspection of large panel and web materials. The sensor however has due to the unprecedented resolution also application potential in earth observation and motion picture context. The sensor features 16384 charge integrating pixels of 3.5um x 3.5um photo active area. Each pixel has it's own charge integrating transconductance amplifier circuit, a true correlated double sampling stage, sample & hold stage and a pixel level 13 bit linear AD converter. Readout is performed over 16 parallel digital output tap's operated at 50MHz pixel clock. The sensor generates at maximum speed a total data rate of 10.4Gbit/s. In order to maximize the integration time, data readout, AD conversion and integration can be performed simultaneously. Therefore even at the maximum line rate of 43kScans/second the integration time can be maintained at 20us. In order to accommodate for different application scenarios with very different lighting budget's, the sensors full well capacity can be programmed by means of a two step programmable gain from 3000e- to 40ke-. The prototype characterization results showed a total quantum efficiency of 72% at 625nm. With the full well capacity set to 26ke- the conversion gain was measured to be 0.13DN/e- with a read noise in dark of 1.7DN, or 12 e- dark noise equivalent. Over all DSNU is reduced to 3DN rms independent of the conversion gain by the on chip combination of CDS and digital DSNU correction. PRNU was measured according the EMVA1288 standard to 1.2% rms. The sensor is mounted on an "Invar" enforced COB board without glass cover for reduced reflections on optical interface stacks. Instead of traditional package leads SMD mounted board to board connectors are used for the electrical connections.

  6. Digital readout integrated circuit (DROIC) implementing time delay and integration (TDI) for scanning type infrared focal plane arrays (IRFPAs)

    Science.gov (United States)

    Ceylan, Omer; Shafique, Atia; Burak, Abdurrahman; Caliskan, Can; Yazici, Melik; Abbasi, Shahbaz; Galioglu, Arman; Kayahan, Huseyin; Gurbuz, Yasar

    2016-11-01

    This paper presents a digital readout integrated circuit (DROIC) implementing time delay and integration (TDI) for scanning type infrared focal plane arrays (IRFPAs) with a charge handling capacity of 44.8 Me- while achieving quantization noise of 198 e- and power consumption of 14.35 mW. Conventional pulse frequency modulation (PFM) method is supported by a single slope ramp ADC technique to have a very low quantization noise together with a low power consumption. The proposed digital TDI ROIC converts the photocurrent into digital domain in two phases; in the first phase, most significant bits (MSBs) are generated by the conventional PFM technique in the charge domain, while in the second phase least significant bits (LSBs) are generated by a single slope ramp ADC in the time domain. A 90 × 8 prototype has been fabricated and verified, showing a significantly improved signal-to-noise ratio (SNR) of 51 dB for low illumination levels (280,000 collected electrons), which is attributed to the TDI implementation method and very low quantization noise due to the single slope ADC implemented for LSBs. Proposed digital TDI ROIC proves the benefit of digital readouts for scanning arrays enabling smaller pixel pitches, better SNR for the low illumination levels and lower power consumption compared to analog TDI readouts for scanning arrays.

  7. Reconfigurable signal processor designs for advanced digital array radar systems

    Science.gov (United States)

    Suarez, Hernan; Zhang, Yan (Rockee); Yu, Xining

    2017-05-01

    The new challenges originated from Digital Array Radar (DAR) demands a new generation of reconfigurable backend processor in the system. The new FPGA devices can support much higher speed, more bandwidth and processing capabilities for the need of digital Line Replaceable Unit (LRU). This study focuses on using the latest Altera and Xilinx devices in an adaptive beamforming processor. The field reprogrammable RF devices from Analog Devices are used as analog front end transceivers. Different from other existing Software-Defined Radio transceivers on the market, this processor is designed for distributed adaptive beamforming in a networked environment. The following aspects of the novel radar processor will be presented: (1) A new system-on-chip architecture based on Altera's devices and adaptive processing module, especially for the adaptive beamforming and pulse compression, will be introduced, (2) Successful implementation of generation 2 serial RapidIO data links on FPGA, which supports VITA-49 radio packet format for large distributed DAR processing. (3) Demonstration of the feasibility and capabilities of the processor in a Micro-TCA based, SRIO switching backplane to support multichannel beamforming in real-time. (4) Application of this processor in ongoing radar system development projects, including OU's dual-polarized digital array radar, the planned new cylindrical array radars, and future airborne radars.

  8. Toward Fast, Low-noise, Low-power, Small Pixel Digital CCDs for X-ray Astronomy

    Science.gov (United States)

    Bautz, Mark W.; Burke, Barry; Cooper, Michael; Foster, Richard; Grant, Catherine E.; LaMarr, Beverly; Malonis, Andrew; Miller, Eric D.; Prigozhin, Gregory; Schuette, Daniel

    2017-08-01

    Future X-ray missions such as Lynx will require large-format imaging detectors with spectroscopic performance at least as good as the best current-generation devices but with much higher readout rates. We have been investigating a detector architecture under development at MIT Lincoln Laboratory, called the Digital CCD, for use in such missions. The Digital CCD is envisioned as a CMOS-compatible detector integrated with parallel CMOS signal processing chains. The combination of fast, low noise CCD amplifiers with highly parallel signal processing offers the high frame-rate required. The CMOS-compatibility of the CCD provides low-power charge transfer.Here we report on the X-ray spectral response of a CMOS-compatible test CCD read at 2.5 MHz (about 25 times faster than the CCDs operating on Chandra ACIS), using transfer clock levels of only +-1 V (power per unit area less than 25 times that of ACIS CCDs). The 8-micron pixels of this device are one third the size of those on Chandra ACIS. We compare charge splitting in this detector with that observed in larger-pixel detectors, and we briefly discuss the implications of the small-pixel, deep-depletion detector configurations required by Lynx.

  9. A 4k-Pixel CTIA Readout for Far IR Photodetector Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design a low noise, two-side buttable, 64x64 readout multiplexer with the following key design features: 1- By far the largest readout array developed...

  10. Design methodology: edgeless 3D ASICs with complex in-pixel processing for pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fahim Farah, Fahim Farah [Northwestern U. (main); Deptuch, Grzegorz W. [Fermilab; Hoff, James R. [Fermilab; Mohseni, Hooman [Northwestern U. (main)

    2015-08-28

    The design methodology for the development of 3D integrated edgeless pixel detectors with in-pixel processing using Electronic Design Automation (EDA) tools is presented. A large area 3 tier 3D detector with one sensor layer and two ASIC layers containing one analog and one digital tier, is built for x-ray photon time of arrival measurement and imaging. A full custom analog pixel is 65μm x 65μm. It is connected to a sensor pixel of the same size on one side, and on the other side it has approximately 40 connections to the digital pixel. A 32 x 32 edgeless array without any peripheral functional blocks constitutes a sub-chip. The sub-chip is an indivisible unit, which is further arranged in a 6 x 6 array to create the entire 1.248cm x 1.248cm ASIC. Each chip has 720 bump-bond I/O connections, on the back of the digital tier to the ceramic PCB. All the analog tier power and biasing is conveyed through the digital tier from the PCB. The assembly has no peripheral functional blocks, and hence the active area extends to the edge of the detector. This was achieved by using a few flavors of almost identical analog pixels (minimal variation in layout) to allow for peripheral biasing blocks to be placed within pixels. The 1024 pixels within a digital sub-chip array have a variety of full custom, semi-custom and automated timing driven functional blocks placed together. The methodology uses a modified mixed-mode on-top digital implementation flow to not only harness the tool efficiency for timing and floor-planning but also to maintain designer control over compact parasitically aware layout. The methodology uses the Cadence design platform, however it is not limited to this tool.

  11. Development of a Digital Tracking Array with Single- Channel RSNS and Monopulse Digital Beamforming

    Science.gov (United States)

    2010-12-01

    digital beamforming (DBF) to track a UAV’s transmitted signal is described in this thesis. The RSNS is used as the direction finding (DF) algorithm and... algorithm and can provide high angle resolution with two closely spaced elements. However, as is typical for an array, the angle accuracy is reduced...25 1. Single-Target Tracker ( STT ) ............................................................25 2

  12. Fourier transform acousto-optic imaging with a custom-designed CMOS smart-pixels array.

    Science.gov (United States)

    Barjean, Kinia; Contreras, Kevin; Laudereau, Jean-Baptiste; Tinet, Éric; Ettori, Dominique; Ramaz, François; Tualle, Jean-Michel

    2015-03-01

    We report acousto-optic imaging (AOI) into a scattering medium using a Fourier Transform (FT) analysis to achieve axial resolution. The measurement system was implemented using a CMOS smart-pixels sensor dedicated to the real-time analysis of speckle patterns. This first proof-of-principle of FT-AOI demonstrates some of its potential advantages, with a signal-to-noise ratio comparable to the one obtained without axial resolution, and with an acquisition rate compatible with a use on living biological tissue.

  13. Design and numerical simulation of a pixelated full stokes micropolarizer array

    Science.gov (United States)

    Wang, Changjiang; Hu, Jingpei; Wang, Chinhua

    2016-10-01

    In this paper, we propose and demonstrate numerically a pixelated component for full Stokes polarization imaging by integrating linear polarizers and circular polarizers on a single silicon chip working in near infrared band ( 1.6μm). The micro linear polarizers collect linear polarizing information from different orientations while the circular polarizers collect left-handed or right-handed circular polarization information such that full Stokes polarization imaging can be implemented on a single chip in real time. Numerical results show that the extinction ratio and TM transmission of linearly polarization can reach 45dB and 78%, respectively, with a linear metallic grating of period 300nm, and the dichroism of left-handed and right-handed circular polarization can reach 55% with a plasmonic chiral structure that is compatible with linear gratings in terms of structure and fabrication. The proposed structure is of significance in real-time full Stokes polarization imaging.

  14. Development of a fast pixel array detector for use in microsecond time-resolved x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Barna, S.L.; Gruner, S.M.; Shepherd, J.A. [Princeton Univ., NJ (United States)] [and others

    1995-08-01

    A large-area pixel x-ray detector is being developed to collect eight successive frames of wide dynamic range two-dimensional images at 200kHz rates. Such a detector, in conjunction with a synchrotron radiation x-ray source, will enable time-resolved x-ray studies of proteins and other materials on time scales which have previously been inaccessible. The detector will consist of an array of fully-depleted 150 micron square diodes connected to a CMOS integrated electronics layer with solder bump-bonding. During each framing period, the current resulting from the x-rays stopped in the diodes is integrated in the electronics layer, and then stored in one of eight storage capacitors underneath the pixel. After the last frame, the capacitors are read out at standard data transmission rates. The detector has been designed for a well-depth of at least 10,000 x-rays (at 20keV), and a noise level of one x-ray. Ultimately, the authors intend to construct a detector with over one million pixels (1024 by 1024). They present the results of their development effort and various features of the design. The electronics design is discussed, with special attention to the performance requirements. The choice and design of the detective diodes, as they relate to x-ray stopping power and charge collection, are presented. An analysis of various methods of bump bonding is also presented. Finally, the authors discuss the possible need for a radiation-blocking layer, to be placed between the electronics and the detective layer, and various methods they have pursued in the construction of such a layer.

  15. Application Of A 1024X1024 Pixel Digital Image Store, With Pulsed Progressive Readout Camera, For Gastro-Intestinal Radiology

    Science.gov (United States)

    Edmonds, E. W.; Rowlands, J. A.; Hynes, D. M.; Toth, B. D.; Porter, A. J.

    1986-06-01

    We discuss the applicability of intensified x-ray television systems for general digital radiography and the requirements necessary for physician acceptance. Television systems for videofluorography when limited to conventional fluoroscopic exposure rates (25uR/s to x-ray intensifier), with particular application to the gastro-intestinal system, all suffer from three problems which tend to degrade the image: (a) lack of resolution, (b) noise, and (c) patient movement. The system to be described in this paper addresses each of these problems. Resolution is that provided by the use of a 1024 x 1024 pixel frame store combined with a 1024 line video camera and a 10"/6" x-ray image intensifier. Problems of noise and sensitivity to patient movement are overcome by using a short but intense burst of radiation to produce the latent image, which is then read off the video camera in a progressive fashion and placed in the digital store. Hard copy is produced from a high resolution multiformat camera, or a high resolution digital laser camera. It is intended that this PPR system will replace the 100mm spot film camera in present use, and will provide information in digital form for further processing and eventual digital archiving.

  16. Design of analog-to-digital converters for energy sensitive hybrid pixel detectors

    NARCIS (Netherlands)

    San Segundo Bello, David; Nauta, Bram; Visschers, Jan

    2001-01-01

    An important feature of hybrid semiconductor pixel detectors is the fact that detector and readout electronics are manufactured separately, allowing the use of industrial state-of-the-art CMOS processes to manufacture the readout electronics. As the feature size of these processes decreases, faster

  17. Design Methodology: ASICs with complex in-pixel processing for Pixel Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fahim, Farah [Fermilab

    2014-10-31

    The development of Application Specific Integrated Circuits (ASIC) for pixel detectors with complex in-pixel processing using Computer Aided Design (CAD) tools that are, themselves, mainly developed for the design of conventional digital circuits requires a specialized approach. Mixed signal pixels often require parasitically aware detailed analog front-ends and extremely compact digital back-ends with more than 1000 transistors in small areas below 100μm x 100μm. These pixels are tiled to create large arrays, which have the same clock distribution and data readout speed constraints as in, for example, micro-processors. The methodology uses a modified mixed-mode on-top digital implementation flow to not only harness the tool efficiency for timing and floor-planning but also to maintain designer control over compact parasitically aware layout.

  18. SuperCam, a 64-pixel heterodyne imaging array for the 870 micron atmospheric window

    CERN Document Server

    Groppi, C; Kulesa, C; Pütz, P; Golish, D; Gensheimer, P; Hedden, A; Bussmann, S; Weinreb, S; Kuiper, T; Kooi, J; Jones, G; Bardin, J; Mani, H S; Lichtenberger, A; Narayanan, G; Groppi, Christopher; Walker, Christopher; Kulesa, Craig; Puetz, Patrick; Golish, Dathon; Gensheimer, Paul; Hedden, Abigail; Bussmann, Shane; Weinreb, Sander; Kuiper, Thomas; Kooi, Jacob; Jones, Glenn; Bardin, Joseph; Mani, Hamdi; Lichtenberger, Arthur; Narayanan, Gopal

    2006-01-01

    We report on the development of SuperCam, a 64 pixel, superheterodyne camera designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. The advent of such a system will provide an order of magnitude increase in mapping speed over what is now available and revolutionize how observational astronomy is performed in this important wavelength regime. Unlike the situation with bolometric detectors, heterodyne receiver systems are coherent, retaining information about both the amplitude and phase of the incident photon stream. From this information a high resolution spectrum of the incident light can be obtained without multiplexing. SuperCam will be constructed by stacking eight, 1x8 rows of fixed tuned, SIS mixers. The IF output of each mixer will be connected to a low-noise, broadband MMIC amplifier integrated in...

  19. Permanent pixels : building blocks for the longevity of digital surrogates of historical photographs

    NARCIS (Netherlands)

    Van Horik, M.P.M.

    2005-01-01

    Within the context of long-term access to digital objects in general this dissertation takes the longevity of digital surrogates of historical photographs into consideration. For memory institutes digitisation of analogue source material, such as historical photographs, is an exciting way to open up

  20. Digital PCR using micropatterned superporous absorbent array chips.

    Science.gov (United States)

    Wang, Yazhen; Southard, Kristopher M; Zeng, Yong

    2016-06-21

    Digital PCR (dPCR) is an emerging technology for genetic analysis and clinical diagnostics. To facilitate the widespread application of dPCR, here we developed a new micropatterned superporous absorbent array chip (μSAAC) which consists of an array of microwells packed with highly porous agarose microbeads. The packed beads construct a hierarchically porous microgel which confers superior water adsorption capacity to enable spontaneous filling of PDMS microwells for fluid compartmentalization without the need of sophisticated microfluidic equipment and operation expertise. Using large λ-DNA as the model template, we validated the μSAAC for stochastic partitioning and quantitative digital detection of DNA molecules. Furthermore, as a proof-of-concept, we conducted dPCR detection and single-molecule sequencing of a mutation prevalent in blood cancer, the chromosomal translocation t(14;18), demonstrating the feasibility of the μSAAC for analysis of disease-associated mutations. These experiments were carried out using the standard molecular biology techniques and instruments. Because of its low cost, ease of fabrication, and equipment-free liquid partitioning, the μSAAC is readily adaptable to general lab settings, which could significantly facilitate the widespread application of dPCR technology in basic research and clinical practice.

  1. A digital magnetic resonance imaging spectrometer using digital signal processor and field programmable gate array.

    Science.gov (United States)

    Liang, Xiao; Binghe, Sun; Yueping, Ma; Ruyan, Zhao

    2013-05-01

    A digital spectrometer for low-field magnetic resonance imaging is described. A digital signal processor (DSP) is utilized as the pulse programmer on which a pulse sequence is executed as a subroutine. Field programmable gate array (FPGA) devices that are logically mapped into the external addressing space of the DSP work as auxiliary controllers of gradient control, radio frequency (rf) generation, and rf receiving separately. The pulse programmer triggers an event by setting the 32-bit control register of the corresponding FPGA, and then the FPGA automatically carries out the event function according to preset configurations in cooperation with other devices; accordingly, event control of the spectrometer is flexible and efficient. Digital techniques are in widespread use: gradient control is implemented in real-time by a FPGA; rf source is constructed using direct digital synthesis technique, and rf receiver is constructed using digital quadrature detection technique. Well-designed performance is achieved, including 1 μs time resolution of the gradient waveform, 1 μs time resolution of the soft pulse, and 2 MHz signal receiving bandwidth. Both rf synthesis and rf digitalization operate at the same 60 MHz clock, therefore, the frequency range of transmitting and receiving is from DC to ~27 MHz. A majority of pulse sequences have been developed, and the imaging performance of the spectrometer has been validated through a large number of experiments. Furthermore, the spectrometer is also suitable for relaxation measurement in nuclear magnetic resonance field.

  2. A digital magnetic resonance imaging spectrometer using digital signal processor and field programmable gate array

    Science.gov (United States)

    Liang, Xiao; Binghe, Sun; Yueping, Ma; Ruyan, Zhao

    2013-05-01

    A digital spectrometer for low-field magnetic resonance imaging is described. A digital signal processor (DSP) is utilized as the pulse programmer on which a pulse sequence is executed as a subroutine. Field programmable gate array (FPGA) devices that are logically mapped into the external addressing space of the DSP work as auxiliary controllers of gradient control, radio frequency (rf) generation, and rf receiving separately. The pulse programmer triggers an event by setting the 32-bit control register of the corresponding FPGA, and then the FPGA automatically carries out the event function according to preset configurations in cooperation with other devices; accordingly, event control of the spectrometer is flexible and efficient. Digital techniques are in widespread use: gradient control is implemented in real-time by a FPGA; rf source is constructed using direct digital synthesis technique, and rf receiver is constructed using digital quadrature detection technique. Well-designed performance is achieved, including 1 μs time resolution of the gradient waveform, 1 μs time resolution of the soft pulse, and 2 MHz signal receiving bandwidth. Both rf synthesis and rf digitalization operate at the same 60 MHz clock, therefore, the frequency range of transmitting and receiving is from DC to ˜27 MHz. A majority of pulse sequences have been developed, and the imaging performance of the spectrometer has been validated through a large number of experiments. Furthermore, the spectrometer is also suitable for relaxation measurement in nuclear magnetic resonance field.

  3. Standard practice for radiological examination using digital detector arrays

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice establishes the minimum requirements for radiological examination for metallic and nonmetallic material using a digital detector array (DDA) system. 1.2 The requirements in this practice are intended to control the quality of radiologic images and are not intended to establish acceptance criteria for parts or materials. 1.3 This practice covers the radiologic examination with DDAs including DDAs described in Practice E2597 such as a device that contains a photoconductor attached to a Thin Film Transistor (TFT) read out structure, a device that has a phosphor coupled directly to an amorphous silicon read-out structure, and devices where a phosphor is coupled to a CMOS (Complementary metal–oxide–semiconductor) array, a Linear Detector Array (LDA) or a CCD (charge coupled device) crystalline silicon read-out structure. 1.4 The DDA shall be selected for an NDT application based on knowledge of the technology described in Guide , and of the selected DDA properties provided by the manufactu...

  4. Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines

    Directory of Open Access Journals (Sweden)

    Lopes RicardoTadeu

    2010-01-01

    Full Text Available Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines.

  5. A Design of a New Column-Parallel Analog-to-Digital Converter Flash for Monolithic Active Pixel Sensor.

    Science.gov (United States)

    Chakir, Mostafa; Akhamal, Hicham; Qjidaa, Hassan

    2017-01-01

    The CMOS Monolithic Active Pixel Sensor (MAPS) for the International Linear Collider (ILC) vertex detector (VXD) expresses stringent requirements on their analog readout electronics, specifically on the analog-to-digital converter (ADC). This paper concerns designing and optimizing a new architecture of a low power, high speed, and small-area 4-bit column-parallel ADC Flash. Later in this study, we propose to interpose an S/H block in the converter. This integration of S/H block increases the sensitiveness of the converter to the very small amplitude of the input signal from the sensor and provides a sufficient time to the converter to be able to code the input signal. This ADC is developed in 0.18 μm CMOS process with a pixel pitch of 35 μm. The proposed ADC responds to the constraints of power dissipation, size, and speed for the MAPS composed of a matrix of 64 rows and 48 columns where each column ADC covers a small area of 35 × 336.76 μm(2). The proposed ADC consumes low power at a 1.8 V supply and 100 MS/s sampling rate with dynamic range of 125 mV. Its DNL and INL are 0.0812/-0.0787 LSB and 0.0811/-0.0787 LSB, respectively. Furthermore, this ADC achieves a high speed more than 5 GHz.

  6. A Comparison of Feature and Pixel-Based Methods for Recognizing Handwritten Bangla Digits

    NARCIS (Netherlands)

    Surinta, Olarik; Schomaker, Lambertus; Wiering, Marco

    2013-01-01

    We propose a novel handwritten character recognition method for isolated handwritten Bangla digits. A feature is introduced for such patterns, the contour angular technique. It is compared to other methods, such as the hotspot feature, the gray-level normalized character image and a basic low-resolu

  7. A Comparison of Feature and Pixel-Based Methods for Recognizing Handwritten Bangla Digits

    NARCIS (Netherlands)

    Surinta, Olarik; Schomaker, Lambertus; Wiering, Marco

    2013-01-01

    We propose a novel handwritten character recognition method for isolated handwritten Bangla digits. A feature is introduced for such patterns, the contour angular technique. It is compared to other methods, such as the hotspot feature, the gray-level normalized character image and a basic

  8. Simultaneous Transmit and Receive Performance of an 8-channel Digital Phased Array

    Science.gov (United States)

    2017-01-16

    Simultaneous Transmit and Receive Performance of an 8- channel Digital Phased Array Jonathan P. Doane, Kenneth E. Kolodziej, Bradley T. Perry MIT...traditional digital cancellation is typically limited by channel noise and distortion. A unique aspect of the ALSTAR digital canceller is the use of...elements, and an 8- channel digital transceiver chassis. width which is mixed to an IF center frequency of 187.5 MHz, supporting digital sampling in the

  9. Characterization of CdTe Sensors with Schottky Contacts Coupled to Charge-Integrating Pixel Array Detectors for X-Ray Science

    CERN Document Server

    Becker, Julian; Shanks, Katherine S; Philipp, Hugh T; Weiss, Joel T; Purohit, Prafull; Chamberlain, Darol; Ruff, Jacob P C; Gruner, Sol M

    2016-01-01

    Pixel Array Detectors (PADs) consist of an x-ray sensor layer bonded pixel-by-pixel to an underlying readout chip. This approach allows both the sensor and the custom pixel electronics to be tailored independently to best match the x-ray imaging requirements. Here we present characterizations of CdTe sensors hybridized with two different charge-integrating readout chips, the Keck PAD and the Mixed-Mode PAD (MM-PAD), both developed previously in our laboratory. The charge-integrating architecture of each of these PADs extends the instantaneous counting rate by many orders of magnitude beyond that obtainable with photon counting architectures. The Keck PAD chip consists of rapid, 8-frame, in-pixel storage elements with framing periods $<$150 ns. The second detector, the MM-PAD, has an extended dynamic range by utilizing an in-pixel overflow counter coupled with charge removal circuitry activated at each overflow. This allows the recording of signals from the single-photon level to tens of millions of x-rays/...

  10. High-speed x-ray imaging with the Keck pixel array detector (Keck PAD) for time-resolved experiments at synchrotron sources

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Hugh T., E-mail: htp2@cornell.edu; Tate, Mark W.; Purohit, Prafull; Shanks, Katherine S.; Weiss, Joel T. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States); Chamberlain, Darol; Gruner, Sol M. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY (United States)

    2016-07-27

    Modern storage rings are readily capable of providing intense x-ray pulses, tens of picoseconds in duration, millions of times per second. Exploiting the temporal structure of these x-ray sources opens avenues for studying rapid structural changes in materials. Many processes (e.g. crack propagation, deformation on impact, turbulence, etc.) differ in detail from one sample trial to the next and would benefit from the ability to record successive x-ray images with single x-ray sensitivity while framing at 5 to 10 MHz rates. To this end, we have pursued the development of fast x-ray imaging detectors capable of collecting bursts of images that enable the isolation of single synchrotron bunches and/or bunch trains. The detector technology used is the hybrid pixel array detector (PAD) with a charge integrating front-end, and high-speed, in-pixel signal storage elements. A 384×256 pixel version, the Keck-PAD, with 150 µm × 150 µm pixels and 8 dedicated in-pixel storage elements is operational, has been tested at CHESS, and has collected data for compression wave studies. An updated version with 27 dedicated storage capacitors and identical pixel size has been fabricated.

  11. Digital Phased Array Ultrasonic Inspection system with dynamic focusing

    Science.gov (United States)

    Hwang, J. S.; Shin, H. J.; Song, S. J.; Song, T. K.

    2000-05-01

    Enhancement of the ultrasonic flaw detection and characterization is expected through the development of a high performance PAULI (Phased Array Ultrasonic Inspection) system which can provide high resolution two-dimensional (sector scan: S-scan) images. The high-resolution S-scan image renders inspection results more readable compared to the conventional A-scan and B-scan results. Therefore, it can improve inspection efficiency and reliability. In this study, the ultrasonic imaging technologies developed in medical applications were adapted to develop a digital PAULI system for nondestructive testing. To provide real-time S-scan images, the PAULI system uses 64 independent transceiver channels controlled by proper delay laws for steering and focusing the ultrasound beams along each scan lines. The PAULI system employs a novel dynamic receive focusing technique in order to optimize the lateral resolution by focusing the ultrasound wave at all imaging points. The dynamic receive focusing is achieved in real-time by digital signal processing methods. The feasibility of PAULI system is demonstrated for the NDE of steel structures.

  12. Submillisecond X-ray photon correlation spectroscopy from a pixel array detector with fast dual gating and no readout dead-time.

    Science.gov (United States)

    Zhang, Qingteng; Dufresne, Eric M; Grybos, Pawel; Kmon, Piotr; Maj, Piotr; Narayanan, Suresh; Deptuch, Grzegorz W; Szczygiel, Robert; Sandy, Alec

    2016-05-01

    Small-angle scattering X-ray photon correlation spectroscopy (XPCS) studies were performed using a novel photon-counting pixel array detector with dual counters for each pixel. Each counter can be read out independently from the other to ensure there is no readout dead-time between the neighboring frames. A maximum frame rate of 11.8 kHz was achieved. Results on test samples show good agreement with simple diffusion. The potential of extending the time resolution of XPCS beyond the limit set by the detector frame rate using dual counters is also discussed.

  13. Submillisecond X-ray photon correlation spectroscopy from a pixel array detector with fast dual gating and no readout dead-time

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qingteng; Dufresne, Eric M.; Grybos, Pawel; Kmon, Piotr; Maj, Piotr; Narayanan, Suresh; Deptuch, Grzegorz W.; Szczygiel, Robert; Sandy, Alec

    2016-04-19

    Small-angle scattering X-ray photon correlation spectroscopy (XPCS) studies were performed using a novel photon-counting pixel array detector with dual counters for each pixel. Each counter can be read out independently from the other to ensure there is no readout dead-time between the neighboring frames. A maximum frame rate of 11.8 kHz was achieved. Results on test samples show good agreement with simple diffusion. The potential of extending the time resolution of XPCS beyond the limit set by the detector frame rate using dual counters is also discussed.

  14. Design and performance of large-pixel-size high-fill-fraction TES arrays for future X-ray astrophysics missions

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa-Feliciano, E. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)]. E-mail: enectali@mit.edu; Bandler, S.R. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Chervenak, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Finkbeiner, F. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Iyomoto, N. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelley, R.L. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kilbourne, C.A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Porter, F.S. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Saab, T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sadleir, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); White, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2006-04-15

    We have designed, modeled, fabricated and tested a 600{mu}m high-fill-fraction microcalorimeter array that will be a good match to the requirements of future X-ray missions. Our devices use transition-edge sensors coupled to overhanging bismuth/copper absorbers to produce arrays with 97% or higher fill fraction. An extensive modeling effort was undertaken in order to accommodate large pixel sizes (500-1000{mu}m) and maintain the best energy resolution possible. The finite thermalization time of the large absorber and the associated position dependence of the pulse shape on absorption position constrain the time constants of the system given a desired energy-resolution performance. We show the results of our analysis and our new pixel design, consisting of a novel TES-on-the-side architecture which creates a controllable TES-absorber conductance.

  15. High resolution stationary digital breast tomosynthesis using distributed carbon nanotube x-ray source array.

    Science.gov (United States)

    Qian, Xin; Tucker, Andrew; Gidcumb, Emily; Shan, Jing; Yang, Guang; Calderon-Colon, Xiomara; Sultana, Shabana; Lu, Jianping; Zhou, Otto; Spronk, Derrek; Sprenger, Frank; Zhang, Yiheng; Kennedy, Don; Farbizio, Tom; Jing, Zhenxue

    2012-04-01

    The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual x-ray sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to x-ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology. A CNT x-ray source array was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maximum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an extended period of time to determine the stable life time of CNT cathode for an expected clinical operation scenario. The source array was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the source array with the detection system and to scan and regulate x-ray beams. The performance of the s-DBT system was evaluated using physical phantoms. The spatially distributed CNT x-ray source array comprised 31 individually addressable x-ray sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maximum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with extended lifetime and good source-to-source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection

  16. Preliminary Clinical Studies Using A Self Scanning Lineak Diode Array To Obtain 1024 X 1024 Digital Radiographs

    Science.gov (United States)

    Sashin, Donald; Slasky, B. Simon; Sternglass, Ernest J.; Bron, Klaus M.; Herron, John M.; Kennedy, William H.; Boyer, Joseph W.; Girdany, Bertram R.; Simpson, Raymond W.; Horton, Joseph A.

    1984-08-01

    A digital radiography system using self scanning linear diode arrays is being developed for improved diagnosis at reduced radiation dose. Our technique is based on the use of solid state sensors with 1024 diodes per inch and with very high dynamic range. The slit geometry of our method results in image improvement and dose reduction by efficiently rejecting scattered x-rays in the patient. In our present configuration the images have a field of view of six inches by six inches or 6 inches by 12 inches and are digitized to 1024 x 1024 pixels with 12 bits. This digital system differs from the conventional digital radiography in that no image intensifier TV fluoroscopy chain is required. Preliminary clinical studies have demonstrated the high detail of our system at low radiation levels. In dog studies the system has clearly visualized very small coronary arteries following aortic root injection of contrast material. Even with intravenous injections some of the coronary arteries could be seen.

  17. TARGET: A digitizing and trigger ASIC for the Cherenkov telescope array

    Science.gov (United States)

    Funk, S.; Jankowsky, D.; Katagiri, H.; Kraus, M.; Okumura, A.; Schoorlemmer, H.; Shigenaka, A.; Tajima, H.; Tibaldo, L.; Varner, G.; Zink, A.; Zorn, J.

    2017-01-01

    The future ground-based gamma-ray observatory Cherenkov Telescope Array (CTA) will feature multiple types of imaging atmospheric Cherenkov telescopes, each with thousands of pixels. To be affiordable, camera concepts for these telescopes have to feature low cost per channel and at the same time meet the requirements for CTA in order to achieve the desired scientific goals. We present the concept of the TeV Array Readout Electronics with GSa/s sampling and Event Trigger (TARGET) Application Specific Circuit (ASIC), envisaged to be used in the cameras of various CTA telescopes, e.g. the Gamma-ray Cherenkov Telescope (GCT), a proposed 2-Mirror Small-Sized Telescope, and the Schwarzschild-Couder Telescope (SCT), a proposed Medium-Sized Telescope. In the latest version of this readout concept the sampling and trigger parts are split into dedicated ASICs, TARGET C and T5TEA, both providing 16 parallel input channels. TARGET C features a tunable sampling rate (usually 1 GSa/s), a 16k sample deep buffier for each channel and on-demand digitization and transmission of waveforms with typical spans of ˜100 ns. The trigger ASIC, T5TEA, provides 4 low voltage diffierential signal (LVDS) trigger outputs and can generate a pedestal voltage independently for each channel. Trigger signals are generated by T5TEA based on the analog sum of the input in four independent groups of four adjacent channels and compared to a threshold set by the user. Thus, T5TEA generates four LVDS trigger outputs, as well as 16 pedestal voltages fed to TARGET C independently for each channel. We show preliminary results of the characterization and testing of TARGET C and T5TEA.

  18. The Sequencing Bead Array (SBA, a next-generation digital suspension array.

    Directory of Open Access Journals (Sweden)

    Michael S Akhras

    Full Text Available Here we describe the novel Sequencing Bead Array (SBA, a complete assay for molecular diagnostics and typing applications. SBA is a digital suspension array using Next-Generation Sequencing (NGS, to replace conventional optical readout platforms. The technology allows for reducing the number of instruments required in a laboratory setting, where the same NGS instrument could be employed from whole-genome and targeted sequencing to SBA broad-range biomarker detection and genotyping. As proof-of-concept, a model assay was designed that could distinguish ten Human Papillomavirus (HPV genotypes associated with cervical cancer progression. SBA was used to genotype 20 cervical tumor samples and, when compared with amplicon pyrosequencing, was able to detect two additional co-infections due to increased sensitivity. We also introduce in-house software Sphix, enabling easy accessibility and interpretation of results. The technology offers a multi-parallel, rapid, robust, and scalable system that is readily adaptable for a multitude of microarray diagnostic and typing applications, e.g. genetic signatures, single nucleotide polymorphisms (SNPs, structural variations, and immunoassays. SBA has the potential to dramatically change the way we perform probe-based applications, and allow for a smooth transition towards the technology offered by genomic sequencing.

  19. The Sequencing Bead Array (SBA), a next-generation digital suspension array.

    Science.gov (United States)

    Akhras, Michael S; Pettersson, Erik; Diamond, Lisa; Unemo, Magnus; Okamoto, Jennifer; Davis, Ronald W; Pourmand, Nader

    2013-01-01

    Here we describe the novel Sequencing Bead Array (SBA), a complete assay for molecular diagnostics and typing applications. SBA is a digital suspension array using Next-Generation Sequencing (NGS), to replace conventional optical readout platforms. The technology allows for reducing the number of instruments required in a laboratory setting, where the same NGS instrument could be employed from whole-genome and targeted sequencing to SBA broad-range biomarker detection and genotyping. As proof-of-concept, a model assay was designed that could distinguish ten Human Papillomavirus (HPV) genotypes associated with cervical cancer progression. SBA was used to genotype 20 cervical tumor samples and, when compared with amplicon pyrosequencing, was able to detect two additional co-infections due to increased sensitivity. We also introduce in-house software Sphix, enabling easy accessibility and interpretation of results. The technology offers a multi-parallel, rapid, robust, and scalable system that is readily adaptable for a multitude of microarray diagnostic and typing applications, e.g. genetic signatures, single nucleotide polymorphisms (SNPs), structural variations, and immunoassays. SBA has the potential to dramatically change the way we perform probe-based applications, and allow for a smooth transition towards the technology offered by genomic sequencing.

  20. The Digital Motion Control System for the Submillimeter Array Antennas

    CERN Document Server

    Hunter, T R; Kimberk, R; Leiker, P S; Patel, N A; Blundell, R; Christensen, R D; Diven, A R; Maute, J; Plante, R J; Riddle, P; Young, K H

    2013-01-01

    We describe the design and performance of the digital servo and motion control system for the 6-meter diameter parabolic antennas of the Submillimeter Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested layers operating at a different, appropriate bandwidth. (1) A rack-mounted, real-time Unix system runs the position loop which reads the high resolution azimuth and elevation encoders and sends velocity and acceleration commands at 100 Hz to a custom-designed servo control board (SCB). (2) The microcontroller-based SCB reads the motor axis tachometers and implements the velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3) The motor amplifiers implement the torque loop by monitoring and sending current to the three-phase brushless drive motors at 20 kHz. The velocity loop uses a traditional proportional-integral-derivative (PID) control algorithm, while the position loop uses only a proportional term and implements a command shaper based on the Gauss error functi...

  1. Preparation, applications, and digital simulation of carbon interdigitated array electrodes.

    Science.gov (United States)

    Liu, Fei; Kolesov, Grigory; Parkinson, B A

    2014-08-05

    Carbon interdigitated array (IDA) electrodes with features sizes down to 1.2 μm were fabricated by controlled pyrolysis of patterned photoresist. Cyclic voltammetry of reversible redox species produced the expected steady-state currents. The collection efficiency depends on the IDA electrode spacing, which ranged from around 2.7 to 16.5 μm, with the smaller dimensions achieving higher collection efficiencies of up to 98%. The signal amplification because of redox cycling makes it possible to detect species at relatively low concentrations (10(-5) molar) and the small spacing allows detection of transient electrogenerated species with much shorter lifetimes (submillisecond). Digital simulation software that accounts for both the width and height of electrode elements as well as the electrode spacing was developed to model the IDA electrode response. The simulations are in quantitative agreement with experimental data for both a simple fast one electron redox reaction and an electron transfer with a following chemical reaction at the IDAs with larger gaps whereas currents measured for the smallest IDA electrodes, that were larger than the simulated currents, are attributed to convection from induced charge electrokinetic flow.

  2. Preparation, Applications, and Digital Simulation of Carbon Interdigitated Array Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fei; Kolesov, Grigory; Parkinson, Bruce A.

    2014-12-16

    Carbon interdigitated array (IDA) electrodes with features sizes down to 1.2 μm were fabricated by controlled pyrolysis of patterned photoresist. Cyclic voltam-metry of reversible redox species produced the expected steady-state currents. The collection efficiency depends on the IDA electrode spacing, which ranged from around 2.7 to 16.5 μm, with the smaller dimensions achieving higher collection efficiencies of up to 98%. The signal amplification because of redox cycling makes it possible to detect species at relatively low concentrations (10–5 molar) and the small spacing allows detection of transient electrogenerated species with much shorter lifetimes (submillisecond). Digital simulation software that accounts for both the width and height of electrode elements as well as the electrode spacing was developed to model the IDA electrode response. The simulations are in quantitative agreement with experimental data for both a simple fast one electron redox reaction and an electron transfer with a following chemical reaction at the IDAs with larger gaps whereas currents measured for the smallest IDA electrodes, that were larger than the simulated currents, are attributed to convection from induced charge electrokinetic flow. This work was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the Department of Energy, Office of Science Office of Basic Energy Sciences.

  3. Performance evaluation of a sub-millimeter spatial resolution PET detector module using a digital silicon photomultiplier coupled LGSO array

    Science.gov (United States)

    Leem, Hyun Tae; Choi, Yong; Kim, Kyu Bom; Lee, Sangwon; Yamamoto, Seiichi; Yeom, Jung-Yeol

    2017-02-01

    In positron emission tomography (PET) for breast, brain and small animal imaging, the spatial resolution of a PET detector is crucial to obtain high quality PET images. In this study, a PET detector for sub-millimeter spatial resolution imaging purpose was assembled using 4×4 pixels of a digital silicon photomultiplier (dSiPM, DPC-3200-22-44, Philips) coupled with a 15×15 LGSO array with BaSO4 reflector, and a 1 mm thick acrylic light guide for light distribution between the dSiPM pixels. The active area of each dSiPM pixel was 3.2×3.9 mm2 and the size of each LGSO scintillator element was 0.7×0.7×6 mm3. In this paper, we experimentally demonstrated the performance of the PET detector by measuring the energy resolution, 2D flood map, peak to valley (P/V) ratio, and coincidence resolving time (CRT). All measurements were performed at a temperature of 10±1 ℃. The average energy resolution was 15.6% (without correcting for saturation effects) at 511 keV and the best CRT was 242±5 ps. The 2D flood map obtained with an energy window of 400-600 keV demonstrated clear identification of all pixels, and the average P/V ratio of the X- and Y-directions were 7.31 and 7.81, respectively. This study demonstrated that the PET detector could be suitable for application in high resolution PET while achieving good timing resolution.

  4. Ping-Pong Beam Training with Hybrid Digital-Analog Antenna Arrays

    DEFF Research Database (Denmark)

    Manchón, Carles Navarro; Carvalho, Elisabeth De; Andersen, Jørgen Bach

    2017-01-01

    In this article we propose an iterative training scheme that approximates optimal beamforming between two transceivers equipped with hybrid digital-analog antenna arrays. Inspired by methods proposed for digital arrays that exploit algebraic power iterations, the proposed training procedure...... is based on a series of alternate (ping-pong) transmissions between the two devices over a reciprocal channel. During the transmissions, the devices updates their digital beamformers by conjugation and normalization operations on the received digital signal, while the analog beamformers are progressively...

  5. Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Konstantinidis, Anastasios C. [Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom and Diagnostic Radiology and Radiation Protection, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX (United Kingdom); Patel, Tushita [Department of Physics, University of Virginia, Charlottesville, Virginia 22908 (United States)

    2015-11-15

    Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e{sup −}) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm{sup 2}) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K{sub a} < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K{sub a} ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at

  6. Signal dependence of inter-pixel capacitance in hybridized HgCdTe H2RG arrays for use in James Webb space telescope's NIRcam

    Science.gov (United States)

    Donlon, Kevan; Ninkov, Zoran; Baum, Stefi

    2016-08-01

    Interpixel capacitance (IPC) is a deterministic electronic coupling by which signal generated in one pixel is measured in neighboring pixels. Examination of dark frames from test NIRcam arrays corroborates earlier results and simulations illustrating a signal dependent coupling. When the signal on an individual pixel is larger, the fractional coupling to nearest neighbors is lesser than when the signal is lower. Frames from test arrays indicate a drop in average coupling from approximately 1.0% at low signals down to approximately 0.65% at high signals depending on the particular array in question. The photometric ramifications for this non-uniformity are not fully understood. This non-uniformity intro-duces a non-linearity in the current mathematical model for IPC coupling. IPC coupling has been mathematically formalized as convolution by a blur kernel. Signal dependence requires that the blur kernel be locally defined as a function of signal intensity. Through application of a signal dependent coupling kernel, the IPC coupling can be modeled computationally. This method allows for simultaneous knowledge of the intrinsic parameters of the image scene, the result of applying a constant IPC, and the result of a signal dependent IPC. In the age of sub-pixel precision in astronomy these effects must be properly understood and accounted for in order for the data to accurately represent the object of observation. Implementation of this method is done through python scripted processing of images. The introduction of IPC into simulated frames is accomplished through convolution of the image with a blur kernel whose parameters are themselves locally defined functions of the image. These techniques can be used to enhance the data processing pipeline for NIRcam.

  7. Per-Pixel Coded Exposure for High-Speed and High-Resolution Imaging Using a Digital Micromirror Device Camera

    Directory of Open Access Journals (Sweden)

    Wei Feng

    2016-03-01

    Full Text Available High-speed photography is an important tool for studying rapid physical phenomena. However, low-frame-rate CCD (charge coupled device or CMOS (complementary metal oxide semiconductor camera cannot effectively capture the rapid phenomena with high-speed and high-resolution. In this paper, we incorporate the hardware restrictions of existing image sensors, design the sampling functions, and implement a hardware prototype with a digital micromirror device (DMD camera in which spatial and temporal information can be flexibly modulated. Combined with the optical model of DMD camera, we theoretically analyze the per-pixel coded exposure and propose a three-element median quicksort method to increase the temporal resolution of the imaging system. Theoretically, this approach can rapidly increase the temporal resolution several, or even hundreds, of times without increasing bandwidth requirements of the camera. We demonstrate the effectiveness of our method via extensive examples and achieve 100 fps (frames per second gain in temporal resolution by using a 25 fps camera.

  8. Per-Pixel Coded Exposure for High-Speed and High-Resolution Imaging Using a Digital Micromirror Device Camera.

    Science.gov (United States)

    Feng, Wei; Zhang, Fumin; Qu, Xinghua; Zheng, Shiwei

    2016-03-04

    High-speed photography is an important tool for studying rapid physical phenomena. However, low-frame-rate CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) camera cannot effectively capture the rapid phenomena with high-speed and high-resolution. In this paper, we incorporate the hardware restrictions of existing image sensors, design the sampling functions, and implement a hardware prototype with a digital micromirror device (DMD) camera in which spatial and temporal information can be flexibly modulated. Combined with the optical model of DMD camera, we theoretically analyze the per-pixel coded exposure and propose a three-element median quicksort method to increase the temporal resolution of the imaging system. Theoretically, this approach can rapidly increase the temporal resolution several, or even hundreds, of times without increasing bandwidth requirements of the camera. We demonstrate the effectiveness of our method via extensive examples and achieve 100 fps (frames per second) gain in temporal resolution by using a 25 fps camera.

  9. Shallow Seismic Reflection Survey at Garner Valley Digital Array

    Science.gov (United States)

    Lawrence, Z. S.; Brackman, T. B.; Bodin, P.; Stephenson, W. J.; Steidl, J. H.; Gomberg, J.

    2004-12-01

    The Garner Valley Digital Array (GVDA) site is a NEES-sponsored facility in a small, sediment-filled, intermountain valley in Southern California, established for the purpose of investigating ground motion site response and soil-structure interaction, in situ. The site has been well-characterized geotechnically, and is thoroughly instrumented with both surface and downhole instrumentation of various types. Nevertheless, a borehole recently drilled into lake bed sediments and deeply weathered granitic rocks that comprise the valley fill at GVDA encountered hard, unweathered bedrock at an unexpected depth, suggesting an apparent 38 meter offset in the unweathered bedrock between two wells 40 meters apart. The apparent offset can be most easily explained either by faulting, or as a buried erosional surface. The Hot Springs fault, a strand of the San Jacinto fault zone, runs through Garner Valley, although its inferred location is several hundred meters east of GVDA. To better characterize the subsurface strata, particularly the existence and configuration of faulting that may disturb them; we conducted a 120-meter long, 12-fold shallow seismic reflection common midpoint (CMP) survey at GVDA using a 24-channel seismograph, vertical 4.5 Hz geophones at 2-meter intervals and a sledgehammer seismic source. Preliminary processing reveals strong refractors and surface waves that may mask reflections, although reflections are visible in some raw shot records. Semi-continuous reflections seen in the CMP section from a shallow reflector may coincide with the water table. There are also deeper, discontinuous reflectors obscured by bands of coherent noise. We plan to present a fully migrated and interpreted CMP record section.

  10. A bit-level systolic array for digital contour smoothing

    NARCIS (Netherlands)

    Petkov, Nikolai; Sloboda, Fridrich

    1989-01-01

    Linear operators for digital contour smoothing are described. These operators are defined by circulant Toeplitz matrices and allow to smooth digital contours in the least-squares sense. They minimize the undersampling, digitizing and quantizing error and allow to calculate invariants, such as curvat

  11. Development of a large-area monolithic 4x4 MPPC array for a future PET scanner employing pixelized Ce:LYSO and Pr:LuAG crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kato, T., E-mail: katou.frme.8180@asagi.waseda.j [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Kataoka, J.; Nakamori, T.; Miura, T.; Matsuda, H. [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Sato, K.; Ishikawa, Y.; Yamamura, K.; Kawabata, N. [Solid State Division, Hamamatsu Photonics K. K., 1126-1, Ichino-cho, Hamamatsu, Shizuoka (Japan); Ikeda, H.; Sato, G. [ISAS/JAXA, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa (Japan); Kamada, K. [Materials Research Laboratory, Furukawa Co., Ltd., 1-25-13, Kannondai, Tsukuba, Ibaraki 305-0856 (Japan)

    2011-05-11

    We have developed a new type of large-area monolithic Multi-Pixel Photon Counter (MPPC) array consisting of a 4x4 matrix of 3x3 mm{sup 2} pixels. Each pixel comprises 3600 Geiger mode avalanche photodiodes (APDs) that achieve an average gain of 9.68x10{sup 5} at 71.9 V at 0 {sup o}C with variations of only {+-}7.2% over 4x4 pixels. Excellent uniformity was also obtained for photon detection efficiencies (PDE) of {+-}6.4%, whilst dark count rates at the single photoelectron (1 p.e.) level amounted to {approx_equal}2Mcps/pixel, measured at 0 {sup o}C. As the first step toward using the device in scintillation photon detectors, we fabricated a prototype gamma-ray camera consisting of an MPPC array optically coupled with a scintillator matrix, namely a 4x4 array of 3x3 x10 mm{sup 3} crystals. Specifically, we tested the performance with Ce-doped (Lu, Y){sub 2}(SiO{sub 4})O (Ce:LYSO), Pr-doped Lu{sub 3}Al{sub 5}O{sub 12} (Pr:LuAG) and 'surface coated' Pr:LuAG (Pr:LuAG (WLS)) matrices whereby the emission peak of Pr:LuAG was shifted from 310 to 420 nm via a wavelength shifter (WLS). Average energy resolutions of 13.83%, 14.70% and 13.96% (FWHM) were obtained for 662 keV gamma-rays, as measured at 0 {sup o}C with Ce:LYSO, Pr:LuAG and Pr:LuAG (WLS) scintillator matrices, respectively. We confirmed that the effective PDE for Pr:LuAG (WLS) had improved by more than 30% compared to original, non-coated Pr:LuAG matrix. These results suggest that a large-area monolithic MPPC array developed here could be promising for future medical imaging, particularly in positron emission tomography (PET).

  12. Simultaneous Transmit and Receive Performance of an 8-Channel Digital Phased Array

    Science.gov (United States)

    2017-01-16

    Receive (STAR) could provide significant benefits for many applications including communications, radar, spectral sens- ing, and multifunctional...shown in Fig . 1. Transmit digital beamforming is used to reduce the total coupled power at each receive element, allowing the receive array to maintain...Canceller Receive Digital Beamfomer Isolated Receive SignalTransmit Signal ALSTAR Transmit Elements ALSTAR Receive Elements ... ... Fig . 1

  13. Evaluation of a photon-counting hybrid pixel detector array with a synchrotron X-ray source

    Science.gov (United States)

    Ponchut, C.; Visschers, J. L.; Fornaini, A.; Graafsma, H.; Maiorino, M.; Mettivier, G.; Calvet, D.

    2002-05-01

    A photon-counting hybrid pixel detector (Medipix-1) has been characterized using a synchrotron X-ray source. The detector consists of a readout ASIC with 64×64 independent photon-counting cells of 170×170 μm 2 pitch, bump-bonded to a 300 μm thick silicon sensor, read out by a PCIbus-based electronics, and a graphical user interface (GUI) software. The intensity and the energy tunability of the X-ray source allow characterization of the detector in the time, space, and energy domains. The system can be read out on external trigger at a frame rate of 100 Hz with 3 ms exposure time per frame. The detector response is tested up to more than 7×10 5 detected events/pixel/s. The point-spread response shows beam reveals no loss in sensitivity between adjacent pixels as could result from charge sharing in the silicon sensor. Photons down to 6 keV can be detected after equalization of the thresholds of individual pixels. The obtained results demonstrate the advantages of photon-counting hybrid pixel detectors and particularly of the Medipix-1 chip for a wide range of X-ray imaging applications, including those using synchrotron X-ray beams.

  14. Evaluation of 320x240 pixel LEC GaAs Schottky barrier X-ray imaging arrays, hybridized to CMOS readout circuit based on charge integration

    CERN Document Server

    Irsigler, R; Alverbro, J; Borglind, J; Froejdh, C; Helander, P; Manolopoulos, S; O'Shea, V; Smith, K

    1999-01-01

    320x240 pixels GaAs Schottky barrier detector arrays were fabricated, hybridized to silicon readout circuits, and subsequently evaluated. The detector chip was based on semi-insulating LEC GaAs material. The square shaped pixel detector elements were of the Schottky barrier type and had a pitch of 38 mu m. The GaAs wafers were thinned down prior to the fabrication of the ohmic back contact. After dicing, the chips were indium bump, flip-chip bonded to CMOS readout circuits based on charge integration, and finally evaluated. A bias voltage between 50 and 100 V was sufficient to operate the detector. Results on I-V characteristics, noise behaviour and response to X-ray radiation are presented. Images of various objects and slit patterns were acquired by using a standard dental imaging X-ray source. The work done was a part of the XIMAGE project financed by the European Community (Brite-Euram). (author)

  15. Performance of the Fully Digital FPGA-based Front-End Electronics for the GALILEO Array

    CERN Document Server

    Barrientos, D; Bazzacco, D; Bortolato, D; Cocconi, P; Gadea, A; González, V; Gulmini, M; Isocrate, R; Mengoni, D; Pullia, A; Recchia, F; Rosso, D; Sanchis, E; Toniolo, N; Ur, C A; Valiente-Dobón, J J

    2014-01-01

    In this work we present the architecture and results of a fully digital Front End Electronics (FEE) read out system developed for the GALILEO array. The FEE system, developed in collaboration with the Advanced Gamma Tracking Array (AGATA) collaboration, is composed of three main blocks: preamplifiers, digitizers and preprocessing electronics. The slow control system contains a custom Linux driver, a dynamic library and a server implementing network services. The digital processing of the data from the GALILEO germanium detectors has demonstrated the capability to achieve an energy resolution of 1.53 per mil at an energy of 1.33 MeV.

  16. A 2D 4×4 Channel Readout ASIC for Pixelated CdTe Detectors for Medical Imaging Applications

    OpenAIRE

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Martínez, Ricardo; Puigdengoles, Carles

    2015-01-01

    We present a 16-channel readout integrated circuit (ROIC) with nanosecond-resolution time to digital converter (TDC) for pixelated Cadmium Telluride (CdTe) gamma-ray detectors. The 4 × 4 pixel array ROIC is the proof of concept of the 10 × 10 pixel array readout ASIC for positron-emission tomography (PET) scanner, positron-emission mammography (PEM) scanner, and Compton gamma camera. The electronics of each individual pixel integrates an analog front-end with switchable gain, an analog to dig...

  17. Evaluation of a photon-counting hybrid pixel detector array with a synchrotron X-ray source

    CERN Document Server

    Ponchut, C; Fornaini, A; Graafsma, H; Maiorino, M; Mettivier, G; Calvet, D

    2002-01-01

    A photon-counting hybrid pixel detector (Medipix-1) has been characterized using a synchrotron X-ray source. The detector consists of a readout ASIC with 64x64 independent photon-counting cells of 170x170 mu m sup 2 pitch, bump-bonded to a 300 mu m thick silicon sensor, read out by a PCIbus-based electronics, and a graphical user interface (GUI) software. The intensity and the energy tunability of the X-ray source allow characterization of the detector in the time, space, and energy domains. The system can be read out on external trigger at a frame rate of 100 Hz with 3 ms exposure time per frame. The detector response is tested up to more than 7x10 sup 5 detected events/pixel/s. The point-spread response shows <2% crosstalk between neighboring pixels. Fine scanning of the detector surface with a 10 mu m beam reveals no loss in sensitivity between adjacent pixels as could result from charge sharing in the silicon sensor. Photons down to 6 keV can be detected after equalization of the thresholds of individu...

  18. Infrared single-pixel imaging utilising microscanning

    CERN Document Server

    Sun, Ming-Jie; Phillips, David B; Gibson, Graham M; Padgett, Miles J

    2015-01-01

    Since the invention of digital cameras there has been a concerted drive towards detector arrays with higher spatial resolution. Microscanning is a technique that provides a final higher resolution image by combining multiple images of a lower resolution. Each of these low resolution images is subject to a sub-pixel sized lateral displacement. In this work we apply the microscanning approach to an infrared single-pixel camera. For the same final resolution and measurement resource, we show that microscanning improves the signal-to-noise ratio (SNR) of reconstructed images by approximately 50%. In addition, this strategy also provides access to a stream of low-resolution 'preview' images throughout each high-resolution acquisition. Our work demonstrates an additional degree of flexibility in the trade-off between SNR and spatial resolution in single-pixel imaging techniques.

  19. Beam-test results of 4k pixel CMOS MAPS and high resistivity striplet detectors equipped with digital sparsified readout in the Slim5 low mass silicon demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Villa, M., E-mail: villa@bo.infn.i [Universita degli Studi di Bologna and INFN-Bologna (Italy); Bruschi, M.; Di Sipio, R.; Fabbri, L.; Giacobbe, B.; Gabrielli, A.; Giorgi, F.; Pellegrini, G.; Sbarra, C.; Semprini, N.; Spighi, R.; Valentinetti, S.; Zoccoli, A. [Universita degli Studi di Bologna and INFN-Bologna (Italy); Avanzini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Calderini, G.; Ceccanti, M.; Cenci, R. [Universita degli Studi di Pisa and INFN-Pisa (Italy)

    2010-05-21

    The results obtained by the Slim5 collaboration on a low material budget tracking silicon demonstrator put on a 12 GeV/c proton test beam at CERN are reported. Inside a reference telescope, two different and innovative detectors were placed for careful tests. The first was a 4k-Pixel Matrix of Deep N Well MAPS, developed in a 130 nm CMOS Technology, square pixels 50{mu}m wide, thinned down to 100{mu}m and equipped with a digital sparsified readout running up to 50 MHz. The other was a high resistivity double sided silicon detector, 200{mu}m thick, with short strips with 50{mu}m pitch at 45{sup 0} angle to the detector's edge. The detectors were equipped with dedicated fast readout architectures performing on-chip data sparsification and providing the timing information for the hits. The criteria followed in the design of the pixel sensor and of the pixel readout architecture will be reviewed. Preliminary measurements of the pixel charge collection, track detection efficiencies and resolutions of pixel and strip sensors are discussed. The data driven architecture of the readout chips has been fully exploited in the test beam by a data acquisition system able to collect on electronic board up to 2.5 Million events per second before triggering. By using a dedicated Associative Memory board, we were able to perform a level 1 trigger system, with minimal latency, identifying cleanly tracks traversing the detectors. System architecture and main performances are shown.

  20. Pixel-level 8-bit 5-MS/s Wilkinson-type digitizer for the DSSC X-ray imager: Concept study

    Science.gov (United States)

    Hansen, K.; Reckleben, C.; Diehl, I.; Bach, M.; Kalavakuru, P.

    2011-02-01

    A pixel-level 8-bit 5-MS/s digitizer for the DSSC X-ray imager utilizing the method of Wilkinson is presented. The timing information is generated column-wise by means of an 8-bit Gray-code counter. The 625-ps time stamps are distributed to the column pixels through 13-mm long shielded coplanar waveguides. Pixel-internal blocks comprise a sample-and-hold stage with current source for ramp generation, a temperature-compensated and supply voltage-stabilized reference circuitry, a comparator, a bank of eight receivers with latches for the time stamps, and control logic. These pixel-internal and global devices in 130-nm CMOS technology occupy 0.015 and 0.012 mm 2, respectively. The power consumption amounts to ˜800 μW at 1.2-V supply voltage. Taking the 0.8-V dynamic range into account, the simulated rms-noise voltage of about 240 μV corresponds to a signal-to-noise ratio above 70 dB. The differential and integral nonlinearity is expected to remain below 0.4 LSB and 1 LSB, respectively. All results promise the compliance with underlying requirements.

  1. Next generation sub-millimeter wave focal plane array coupling concepts: an ESA TRP project to develop multichroic focal plane pixels for future CMB polarization experiments

    Science.gov (United States)

    Trappe, N.; Bucher, M.; De Bernardis, P.; Delabrouille, J.; Deo, P.; DePetris, M.; Doherty, S.; Ghribi, A.; Gradziel, M.; Kuzmin, L.; Maffei, B.; Mahashabde, S.; Masi, S.; Murphy, J. A.; Noviello, F.; O'Sullivan, C.; Pagano, L.; Piacentini, F.; Piat, M.; Pisano, G.; Robinson, M.; Stompor, R.; Tartari, A.; van der Vorst, M.; Verhoeve, P.

    2016-07-01

    The main objective of this activity is to develop new focal plane coupling array concepts and technologies that optimise the coupling from reflector optics to the large number of detectors for next generation sub millimetre wave telescopes particularly targeting measurement of the polarization of the cosmic microwave background (CMB). In this 18 month TRP programme the consortium are tasked with developing, manufacturing and experimentally verifying a prototype multichroic pixel which would be suitable for the large focal plane arrays which will be demanded to reach the required sensitivity of future CMB polarization missions. One major development was to have multichroic operation to potentially reduce the required focal plane size of a CMB mission. After research in the optimum telescope design and definition of requirements based on a stringent science case review, a number of compact focal plane architecture concepts were investigated before a pixel demonstrator consisting of a planar mesh lens feeding a backend Resonant Cold Electron Bolometer RCEB for filtering and detection of the dual frequency signal was planned for manufacture and test. In this demonstrator the frequencies of the channels was chosen to be 75 and 105 GHz in the w band close to the peak CMB signal. In the next year the prototype breadboards will be developed to test the beams produced by the manufactured flat lenses fed by a variety of antenna configurations and the spectral response of the RCEBs will also be verified.

  2. Detailed study of the column-based priority logic readout of Topmetal-II- CMOS pixel direct charge sensor

    CERN Document Server

    An, Mangmang; Gao, Chaosong; Han, Mikyung; Huang, Guangming; Ji, Rong; Li, Xiaoting; Mei, Yuan; Pei, Hua; Sun, Quan; Sun, Xiangming; Wang, Kai; Xiao, Le; Yang, Ping; Zhang, Wei; Zhou, Wei

    2016-01-01

    We present the detailed study of the digital readout of Topmetal-II- CMOS pixel direct charge sensor. Topmetal-II- is an integrated sensor with an array of 72X72 pixels each capable of directly collecting external charge through exposed metal electrodes in the topmost metal layer. In addition to the time-shared multiplexing readout of the analog output from Charge Sensitive Amplifiers in each pixel, hits are also generated through comparators with individually DAC settable thresholds in each pixel. The hits are read out via a column-based priority logic structure, retaining both hit location and time information. The in-array column-based priority logic is fully combinational hence there is no clock distributed in the pixel array. Sequential logic and clock are placed on the peripheral of the array. We studied the detailed working behavior and performance of this readout, and demonstrated its potential in imaging applications.

  3. Digitalization decoupling method and its application to the phased array in MRI

    Institute of Scientific and Technical Information of China (English)

    SONG Xiaoyu; WANG Weidong; ZHANG Bida; LEI Ming; BAO Shanglian

    2003-01-01

    A general network decoupling method for phased array radio frequency coil used in magnetic resonance imaging is developed. A more flexible digital approach further simplifies the method, which has an even higher signal-to-noise ratio. The performance of the digitalized decoupling method was confirmed by the calculated result by using a high frequency structure simulation software with the method of finite element for a tree-port phased array RF coil. The consistence was well established between the theoretical and simulated results.

  4. Optical Manipulation of Single Magnetic Beads in a Microwell Array on a Digital Microfluidic Chip.

    Science.gov (United States)

    Decrop, Deborah; Brans, Toon; Gijsenbergh, Pieter; Lu, Jiadi; Spasic, Dragana; Kokalj, Tadej; Beunis, Filip; Goos, Peter; Puers, Robert; Lammertyn, Jeroen

    2016-09-01

    The detection of single molecules in magnetic microbead microwell array formats revolutionized the development of digital bioassays. However, retrieval of individual magnetic beads from these arrays has not been realized until now despite having great potential for studying captured targets at the individual level. In this paper, optical tweezers were implemented on a digital microfluidic platform for accurate manipulation of single magnetic beads seeded in a microwell array. Successful optical trapping of magnetic beads was found to be dependent on Brownian motion of the beads, suggesting a 99% chance of trapping a vibrating bead. A tailor-made experimental design was used to screen the effect of bead type, ionic buffer strength, surfactant type, and concentration on the Brownian activity of beads in microwells. With the optimal conditions, the manipulation of magnetic beads was demonstrated by their trapping, retrieving, transporting, and repositioning to a desired microwell on the array. The presented platform combines the strengths of digital microfluidics, digital bioassays, and optical tweezers, resulting in a powerful dynamic microwell array system for single molecule and single cell studies.

  5. A Circular aperture-array structure optical system for digital sun sensor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the first type of Rayleigh Sommerfeld diffraction formula, an imaging model of circular aperture-array structure digital sun sensor optical system is developed. Then a 6×6 circular aperture-array structure optical system is designed. The results of numerical simulation show that the optical system is designed well and is conformed to the requirements of miniaturization and high accuracy of sun sensor.

  6. Digital model of TiO(2 memristor for field-programmable gate array

    Directory of Open Access Journals (Sweden)

    Guangyi Wang

    2014-03-01

    Full Text Available A digital model which imitates the behaviour of a TiO(2 memristor as a new block in Alter DSP Builder is proposed in this Letter. The proposed model can be used as an independent memristor unit working with other units for designing memristor circuits based on field-programmable gate array. The accuracy of the digital model is confirmed not only by simulations, but also by hardwire experiments.

  7. Polarisation measurements with a CdTe pixel array detector for Laue hard X-ray focusing telescopes

    CERN Document Server

    Caroli, E; Pisa, A; Stephen, J B; Frontera, F; Castanheira, M T D; Sordo, S; Caroli, Ezio; Silva, Rui M. Curado da; Pisa, Alessandro; Stephen, John B.; Frontera, Filippo; Castanheira, Matilde T. D.; Sordo, Stefano del

    2006-01-01

    Polarimetry is an area of high energy astrophysics which is still relatively unexplored, even though it is recognized that this type of measurement could drastically increase our knowledge of the physics and geometry of high energy sources. For this reason, in the context of the design of a Gamma-Ray Imager based on new hard-X and soft gamma ray focusing optics for the next ESA Cosmic Vision call for proposals (Cosmic Vision 2015-2025), it is important that this capability should be implemented in the principal on-board instrumentation. For the particular case of wide band-pass Laue optics we propose a focal plane based on a thick pixelated CdTe detector operating with high efficiency between 60-600 keV. The high segmentation of this type of detector (1-2 mm pixel size) and the good energy resolution (a few keV FWHM at 500 keV) will allow high sensitivity polarisation measurements (a few % for a 10 mCrab source in 106s) to be performed. We have evaluated the modulation Q factors and minimum detectable polaris...

  8. Advanced power analysis methodology targeted to the optimization of a digital pixel readout chip design and its critical serial powering system

    Science.gov (United States)

    Marconi, S.; Orfanelli, S.; Karagounis, M.; Hemperek, T.; Christiansen, J.; Placidi, P.

    2017-02-01

    A dedicated power analysis methodology, based on modern digital design tools and integrated with the VEPIX53 simulation framework developed within RD53 collaboration, is being used to guide vital choices for the design and optimization of the next generation ATLAS and CMS pixel chips and their critical serial powering circuit (shunt-LDO). Power consumption is studied at different stages of the design flow under different operating conditions. Significant effort is put into extensive investigations of dynamic power variations in relation with the decoupling seen by the powering network. Shunt-LDO simulations are also reported to prove the reliability at the system level.

  9. The NUC and blind pixel eliminating in the DTDI application

    Science.gov (United States)

    Su, Xiao Feng; Chen, Fan Sheng; Pan, Sheng Da; Gong, Xue Yi; Dong, Yu Cui

    2013-12-01

    AS infrared CMOS Digital TDI (Time Delay and integrate) has a simple structure, excellent performance and flexible operation, it has been used in more and more applications. Because of the limitation of the Production process level, the plane array of the infrared detector has a large NU (non-uniformity) and a certain blind pixel rate. Both of the two will raise the noise and lead to the TDI works not very well. In this paper, for the impact of the system performance, the most important elements are analyzed, which are the NU of the optical system, the NU of the Plane array and the blind pixel in the Plane array. Here a reasonable algorithm which considers the background removal and the linear response model of the infrared detector is used to do the NUC (Non-uniformity correction) process, when the infrared detector array is used as a Digital TDI. In order to eliminate the impact of the blind pixel, the concept of surplus pixel method is introduced in, through the method, the SNR (signal to noise ratio) can be improved and the spatial and temporal resolution will not be changed. Finally we use a MWIR (Medium Ware Infrared) detector to do the experiment and the result proves the effectiveness of the method.

  10. High Resolution Spectrum Estimation for Digital Tracking Array

    Science.gov (United States)

    2009-12-01

    local oscillator MRSS multi-resolution spectrum sensing MUSIC multiple signal classification PLL phase lock loop Q quad-phase RSNS...provide the initial tuning for the local oscillator (LO) and phase lock loop ( PLL ) to synchronize to the desired frequency. Due to the digital nature of...longer than that for a compiled program, such as LABVIEW . 85 Table 6. Summary of Simulation Results. Method SNR (dB

  11. 3D reconstructions with pixel-based images are made possible by digitally clearing plant and animal tissue

    Science.gov (United States)

    Reconstruction of 3D images from a series of 2D images has been restricted by the limited capacity to decrease the opacity of surrounding tissue. Commercial software that allows color-keying and manipulation of 2D images in true 3D space allowed us to produce 3D reconstructions from pixel based imag...

  12. Increased space-bandwidth product in pixel super-resolved lensfree on-chip microscopy

    Science.gov (United States)

    Greenbaum, Alon; Luo, Wei; Khademhosseinieh, Bahar; Su, Ting-Wei; Coskun, Ahmet F.; Ozcan, Aydogan

    2013-04-01

    Pixel-size limitation of lensfree on-chip microscopy can be circumvented by utilizing pixel-super-resolution techniques to synthesize a smaller effective pixel, improving the resolution. Here we report that by using the two-dimensional pixel-function of an image sensor-array as an input to lensfree image reconstruction, pixel-super-resolution can improve the numerical aperture of the reconstructed image by ~3 fold compared to a raw lensfree image. This improvement was confirmed using two different sensor-arrays that significantly vary in their pixel-sizes, circuit architectures and digital/optical readout mechanisms, empirically pointing to roughly the same space-bandwidth improvement factor regardless of the sensor-array employed in our set-up. Furthermore, such a pixel-count increase also renders our on-chip microscope into a Giga-pixel imager, where an effective pixel count of ~1.6-2.5 billion can be obtained with different sensors. Finally, using an ultra-violet light-emitting-diode, this platform resolves 225 nm grating lines and can be useful for wide-field on-chip imaging of nano-scale objects, e.g., multi-walled-carbon-nanotubes.

  13. A novel gamma-ray detector with submillimeter resolutions using a monolithic MPPC array with pixelized Ce:LYSO and Ce:GGAG crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kato, T., E-mail: katou.frme.8180@asagi.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Kataoka, J.; Nakamori, T.; Miura, T.; Matsuda, H.; Kishimoto, A. [Research Institute for Science and Engineering, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo (Japan); Sato, K.; Ishikawa, Y.; Yamamura, K.; Nakamura, S.; Kawabata, N. [Solid State Division, Hamamatsu Photonics K. K., 1126-1, Ichino-cho, Hamamatsu, Shizuoka (Japan); Ikeda, H. [ISAS/JAXA, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa (Japan); Yamamoto, S. [Kobe City College of Technology, 8-3, Gakuenhigashimati, Nishi-ku, Kobe-shi, Hyougo 651-2194 (Japan); Kamada, K. [Materials Research Laboratory, Furukawa Co., Ltd., 1-25-13, Kannondai, Tsukuba, Ibaraki 305-0856 (Japan)

    2013-01-21

    We have developed a large-area monolithic Multi-Pixel Photon Counter (MPPC) array consisting of 4×4 channels with a three-side buttable package. Each channel has a photosensitive area of 3×3 mm{sup 2} and 3600 Geiger mode avalanche photodiodes (APDs). For typical operational gain of 7.5×10{sup 5} at +20 °C, gain fluctuation over the entire MPPC device is only ±5.6%, and dark count rates (as measured at the 1 p.e. level) amount to ≤400kcps per channel. We first fabricated a gamma-ray camera consisting of the MPPC array with one-to-one coupling to a Ce-doped (Lu,Y){sub 2}(SiO{sub 4})O (Ce:LYSO) crystal array (4×4 array of 3×3×10 mm{sup 3} crystals). Energy and time resolutions of 11.5±0.5% (FWHM at 662 keV) and 493±22ps were obtained, respectively. When using the charge division resistor network, which compiles signals into four position-encoded analog outputs, the ultimate positional resolution is estimated as 0.19 mm in both X and Y directions, while energy resolution of 10.2±0.4% (FWHM) was obtained. Finally, we fabricated submillimeter Ce:LYSO and Ce-doped Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12} (Ce:GGAG) scintillator matrices each consisting of 1.0×1.0, 0.7×0.7 and 0.5×0.5 mm{sup 2} pixels, to further improve the spatial resolution. In all types of Ce:LYSO and Ce:GGAG matrices, each crystal was clearly resolved in the position histograms when irradiated by a {sup 137}Cs source. The energy resolutions for 662 keV gamma-rays for each Ce:LYSO and Ce:GGAG scintillator matrix were ≤14.3%. These results suggest excellent potential for its use as a high spatial medical imaging device, particularly in positron emission tomography (PET). -- Highlights: ► We developed a newly designed large-area monolithic MPPC array. ► We obtained fine gain uniformity, and good energy and time resolutions when coupled to the LYSO scintillator. ► We fabricated gamma-ray camera consisting of the MPPC array and submillimeter pixelized LYSO and GGAG scintillators. ► In

  14. ASIC Readout Circuit Architecture for Large Geiger Photodiode Arrays

    Science.gov (United States)

    Vasile, Stefan; Lipson, Jerold

    2012-01-01

    The objective of this work was to develop a new class of readout integrated circuit (ROIC) arrays to be operated with Geiger avalanche photodiode (GPD) arrays, by integrating multiple functions at the pixel level (smart-pixel or active pixel technology) in 250-nm CMOS (complementary metal oxide semiconductor) processes. In order to pack a maximum of functions within a minimum pixel size, the ROIC array is a full, custom application-specific integrated circuit (ASIC) design using a mixed-signal CMOS process with compact primitive layout cells. The ROIC array was processed to allow assembly in bump-bonding technology with photon-counting infrared detector arrays into 3-D imaging cameras (LADAR). The ROIC architecture was designed to work with either common- anode Si GPD arrays or common-cathode InGaAs GPD arrays. The current ROIC pixel design is hardwired prior to processing one of the two GPD array configurations, and it has the provision to allow soft reconfiguration to either array (to be implemented into the next ROIC array generation). The ROIC pixel architecture implements the Geiger avalanche quenching, bias, reset, and time to digital conversion (TDC) functions in full-digital design, and uses time domain over-sampling (vernier) to allow high temporal resolution at low clock rates, increased data yield, and improved utilization of the laser beam.

  15. Fabrication of a curved microlens array using double gray-scale digital maskless lithography

    Science.gov (United States)

    Luo, Ningning; Zhang, Zhimin

    2017-03-01

    Digital maskless lithography is considered to be a high-efficiency and low-cost approach for the fabrication of microstructures, but is limited by the gray scale capability of spatial light modulators. In this work, a novel method of double gray-scale digital maskless lithography is presented for forming a curved microlens array. The target exposure dose profile of the curved microlens array is first split into two individual 3D energy profiles, and then each 3D energy profile can be respectively realized by a single gray-scale digital lithography. Two gray-scale digital masks obtained by projection calculation are superposed on the substrate so as to realize the exposure dose profile of the curved microlens array. Thus, the effective steps that are achieved through the photoresist response to the modulated UV exposure are doubled, so a smoother profile with a steep gradient can be formed by the precise modulation of double gray-scale masks. As a result of the double gray-scale method, a curved microlens array with 183 micro lenslets on a 1024 µm  ×  768 µm spherical surface has been successfully fabricated.

  16. Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits.

    Science.gov (United States)

    Aull, Brian

    2016-04-08

    This article reviews MIT Lincoln Laboratory's work over the past 20 years to develop photon-sensitive image sensors based on arrays of silicon Geiger-mode avalanche photodiodes. Integration of these detectors to all-digital CMOS readout circuits enable exquisitely sensitive solid-state imagers for lidar, wavefront sensing, and passive imaging.

  17. Multi-Mode FMCW Radar Array with Independent Digital Beam Steering for Transmit and Receive

    NARCIS (Netherlands)

    Dijk, R. van; Houwen, E.H. van der; Maas, A.P.M.

    2008-01-01

    A phased-array FMCW radar has been design and built from COTS components. The generation of the frequency sweep is done by mixing a central local oscillator signal with a baseband sweep of a direct digital synthesizer (DDS). To ensure maximum flexibility the receive side has been equipped with it's

  18. Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits

    Directory of Open Access Journals (Sweden)

    Brian Aull

    2016-04-01

    Full Text Available This article reviews MIT Lincoln Laboratory's work over the past 20 years to develop photon-sensitive image sensors based on arrays of silicon Geiger-mode avalanche photodiodes. Integration of these detectors to all-digital CMOS readout circuits enable exquisitely sensitive solid-state imagers for lidar, wavefront sensing, and passive imaging.

  19. Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits

    OpenAIRE

    Brian Aull

    2016-01-01

    This article reviews MIT Lincoln Laboratory's work over the past 20 years to develop photon-sensitive image sensors based on arrays of silicon Geiger-mode avalanche photodiodes. Integration of these detectors to all-digital CMOS readout circuits enable exquisitely sensitive solid-state imagers for lidar, wavefront sensing, and passive imaging.

  20. An Undergraduate Course and Laboratory in Digital Signal Processing with Field Programmable Gate Arrays

    Science.gov (United States)

    Meyer-Base, U.; Vera, A.; Meyer-Base, A.; Pattichis, M. S.; Perry, R. J.

    2010-01-01

    In this paper, an innovative educational approach to introducing undergraduates to both digital signal processing (DSP) and field programmable gate array (FPGA)-based design in a one-semester course and laboratory is described. While both DSP and FPGA-based courses are currently present in different curricula, this integrated approach reduces the…

  1. Development of an Ultrahigh Resolution Block Detector Based on 0.4 mm Pixel Ce:GAGG Scintillators and a Silicon Photomultiplier Array

    Science.gov (United States)

    Yamamoto, Seiichi; Yeom, Jung Yeol; Kamada, Kei; Endo, Takanori; Levin, Craig S.

    2013-12-01

    Ce doped Gd3Al2Ga3O12 (Ce:GAGG) is a newly developed single-crystal scintillator which has a large light output and longer emission light wavelength. The longer wavelength of the scintillation photons will produce a larger signal when coupled to typical silicon photomultiplier (Si-PM) as the quantum efficiency of semiconductor based photodetector is generally higher for light with longer wavelength. A block detector with higher spatial resolution may thus be realized by combining Ce:GAGG with Si-PM arrays. To achieve the highest possible spatial resolution for PET and SPECT detectors, we developed an ultrahigh resolution block detector using 0.4 mm × 0.4 mm × 5 mm Ce:GAGG pixels assembled to form a 24 × 24 matrix that is coupled to an Si-PM array and evaluated the performance. All Ce:GAGG pixels were separated in the 2-dimensional position histograms for Cs-137 (662 keV) gamma photons with an average peak-to-valley (P/V) ratio of 2.4. The energy resolution was 21.6% FWHM for Cs-137 (662 keV) and 23.8% for Co-57 (122 keV) gamma photons. Since Ce:GAGG does not contain naturally occurring radioisotope (Lu), beta-gamma true coincidences can be avoided and randoms are reduced when used for PET detectors. Furthermore, this property, together with its high light output and good intrinsic energy resolution, make the scintillator suited for SPECT detectors. An ultrahigh resolution PET/SPECT hybrid system might be an interesting application using Ce:GAGG/Si-PM block detectors.

  2. Realization of 16-channel digital PGC demodulator for fiber laser sensor array

    Energy Technology Data Exchange (ETDEWEB)

    Wang Lin; He Jun; Li Fang; Liu Yuliang, E-mail: wlcas@semi.ac.cn [Optoelectronics System Laboratory, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China)

    2011-02-01

    This paper describes a 16-element DFB FL (distributed feedback fiber laser) sensor array system interrogated by NI-PXI-based (PCI extensions for Instrumentation) digital PGC (phase generated carrier) technique. The lasing wavelengths of the DFB FLs are changed by the external strains or temperatures, and hence they can be used as sensors by detecting the wavelength shifts. An unbalanced MI (Michelson interferometer) is employed in the sensor array system to amplify the wavelength shifts of DFB FL sensors to detectable phase shifts. The output phase signals of the MI are separated into different channels by a DWDM, and then detected by a low-noise photodiode array. The digital PGC algorithm is realized on a PXI platform (NI, National Instruments), which consists of three FPGA (Field Programmable Gate Array) modules and a high performance system controller. The normalization of the interference fringe is proposed and realized in this paper to reduce the influence of the light intensity fluctuations, and a trigger mechanism is introduced into the digital multi-channel PGC demodulation scheme to synchronize the date among different channels. A 16-element DFB fiber laser sensor array system has been set up in the experiment and the demodulated results have demonstrated a minimum detectable wavelength shift of 1x10{sup -6} pmA/{radical}Hz, a linearity of as high as 0.9994, and a dynamic range of 110dB-100Hz.

  3. A novel gamma-ray detector with submillimeter resolutions using a monolithic MPPC array with pixelized Ce:LYSO and Ce:GGAG crystals

    Science.gov (United States)

    Kato, T.; Kataoka, J.; Nakamori, T.; Miura, T.; Matsuda, H.; Kishimoto, A.; Sato, K.; Ishikawa, Y.; Yamamura, K.; Nakamura, S.; Kawabata, N.; Ikeda, H.; Yamamoto, S.; Kamada, K.

    2013-01-01

    We have developed a large-area monolithic Multi-Pixel Photon Counter (MPPC) array consisting of 4×4 channels with a three-side buttable package. Each channel has a photosensitive area of 3×3 mm2 and 3600 Geiger mode avalanche photodiodes (APDs). For typical operational gain of 7.5×105 at +20 °C, gain fluctuation over the entire MPPC device is only ±5.6%, and dark count rates (as measured at the 1 p.e. level) amount to ≤400 kcps per channel. We first fabricated a gamma-ray camera consisting of the MPPC array with one-to-one coupling to a Ce-doped (Lu, Y)2(SiO4)O (Ce:LYSO) crystal array (4×4 array of 3×3×10 mm3 crystals). Energy and time resolutions of 11.5±0.5% (FWHM at 662 keV) and 493±22 ps were obtained, respectively. When using the charge division resistor network, which compiles signals into four position-encoded analog outputs, the ultimate positional resolution is estimated as 0.19 mm in both X and Y directions, while energy resolution of 10.2±0.4% (FWHM) was obtained. Finally, we fabricated submillimeter Ce:LYSO and Ce-doped Gd3Ga3Al2O12 (Ce:GGAG) scintillator matrices each consisting of 1.0×1.0, 0.7×0.7 and 0.5×0.5 mm2 pixels, to further improve the spatial resolution. In all types of Ce:LYSO and Ce:GGAG matrices, each crystal was clearly resolved in the position histograms when irradiated by a 137Cs source. The energy resolutions for 662 keV gamma-rays for each Ce:LYSO and Ce:GGAG scintillator matrix were ≤14.3%. These results suggest excellent potential for its use as a high spatial medical imaging device, particularly in positron emission tomography (PET).

  4. Effect of Pixel's Spatial Characteristics on Recognition of Isolated Pixelized Chinese Character.

    Science.gov (United States)

    Yang, Kun; Liu, Shuang; Wang, Hong; Liu, Wei; Wu, Yaowei

    2015-01-01

    The influence of pixel's spatial characteristics on recognition of isolated Chinese character was investigated using simulated prosthestic vision. The accuracy of Chinese character recognition with 4 kinds of pixel number (6*6, 8*8, 10*10, and 12*12 pixel array) and 3 kinds of pixel shape (Square, Dot and Gaussian) and different pixel spacing were tested through head-mounted display (HMD). A captured image of Chinese characters in font style of Hei were pixelized with Square, Dot and Gaussian pixel. Results showed that pixel number was the most important factor which could affect the recognition of isolated pixelized Chinese Chartars and the accuracy of recognition increased with the addition of pixel number. 10*10 pixel array could provide enough information for people to recognize an isolated Chinese character. At low resolution (6*6 and 8*8 pixel array), there were little difference of recognition accuracy between different pixel shape and different pixel spacing. While as for high resolution (10*10 and 12*12 pixel array), the fluctuation of pixel shape and pixel spacing could not affect the performance of recognition of isolated pixelized Chinese Character.

  5. Digital Spectro-Correlator System for the Atacama Compact Array of the Atacama Large Millimeter/submillimeter Array

    CERN Document Server

    Kamazaki, T; Chikada, Y; Okuda, T; Kurono, Y; Iguchi, S; Mitsuishi, S; Murakami, Y; Nishimuta, N; Mita, H; Sano, R

    2011-01-01

    We have developed an FX-architecture digital spectro-correlator for the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array. The correlator is able to simultaneously process four pairs of dual polarization signals with the bandwidth of 2 GHz, which are received by up to sixteen antennas. It can calculate auto- and cross-correlation spectra including cross-polarization in all combinations of all the antennas, and output correlation spectra with flexible spectral configuration such as multiple frequency ranges and multiple frequency resolutions. Its spectral dynamic range is estimated to be higher than 10^4 relative to Tsys from processing results of thermal noise for eight hours with a typical correlator configuration. The sensitivity loss is also confirmed to be 0.9 % with the same configuration. In this paper, we report the detailed design of the correlator and the verification results of the developed hardware.

  6. Composite x-ray image assembly for large-field digital mammography with one- and two-dimensional positioning of a focal plane array

    Science.gov (United States)

    Halama, G.; McAdoo, J.; Liu, H.

    1998-01-01

    To demonstrate the feasibility of a novel large-field digital mammography technique, a 1024 x 1024 pixel Loral charge-coupled device (CCD) focal plane array (FPA) was positioned in a mammographic field with one- and two-dimensional scan sequences to obtain 950 x 1800 pixel and 3600 x 3600 pixel composite images, respectively. These experiments verify that precise positioning of FPAs produced seamless composites and that the CCD mosaic concept has potential for high-resolution, large-field imaging. The proposed CCD mosaic concept resembles a checkerboard pattern with spacing left between the CCDs for the driver and readout electronics. To obtain a complete x-ray image, the mosaic must be repositioned four times, with an x-ray exposure at each position. To reduce the patient dose, a lead shield with appropriately patterned holes is placed between the x-ray source and the patient. The high-precision motorized translation stages and the fiber-coupled-scintillating-screen-CCD sensor assembly were placed in the position usually occupied by the film cassette. Because of the high mechanical precision, seamless composites were constructed from the subimages. This paper discusses the positioning, image alignment procedure, and composite image results. The paper only addresses the formation of a seamless composite image from subimages and will not consider the effects of the lead shield, multiple CCDs, or the speed of motion.

  7. Toward VIP-PIX: A Low Noise Readout ASIC for Pixelated CdTe Gamma-Ray Detectors for Use in the Next Generation of PET Scanners

    OpenAIRE

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Puigdengoles, Carles; Lorenzo, Gianluca De; Martínez, Ricardo

    2013-01-01

    VIP-PIX will be a low noise and low power pixel readout electronics with digital output for pixelated Cadmium Telluride (CdTe) detectors. The proposed pixel will be part of a 2D pixel-array detector for various types of nuclear medicine imaging devices such as positron-emission tomography (PET) scanners, Compton gamma cameras, and positron-emission mammography (PEM) scanners. Each pixel will include a SAR ADC that provides the energy deposited with 10-bit resolution. Simultaneously, the self-...

  8. Pixel-Level Digital-to-Analog Conversion Scheme with Compensation of Thin-Film-Transistor Variations for Compact Integrated Data Drivers of Active Matrix Organic Light Emitting Diodes

    Science.gov (United States)

    Kim, Tae-Wook; Park, Sang-Gyu; Choi, Byong-Deok

    2011-03-01

    The previous pixel-level digital-to-analog-conversion (DAC) scheme that implements a part of a DAC in a pixel circuit turned out to be very efficient for reducing the peripheral area of an integrated data driver fabricated with low-temperature polycrystalline silicon thin-film transistors (LTPS TFTs). However, how the pixel-level DAC can be compatible with the existing pixel circuits including compensation schemes of TFT variations and IR drops on supply rails, which is of primary importance for active matrix organic light emitting diodes (AMOLEDs) is an issue in this scheme, because LTPS TFTs suffer from random variations in their characteristics. In this paper, we show that the pixel-level DAC scheme can be successfully used with the previous compensation schemes by giving two examples of voltage- and current-programming pixels. The previous pixel-level DAC schemes require additional two TFTs and one capacitor, but for these newly proposed pixel circuits, the overhead is no more than two TFTs by utilizing the already existing capacitor. In addition, through a detailed analysis, it has been shown that the pixel-level DAC can be expanded to a 4-bit resolution, or be applied together with 1:2 demultiplexing driving for 6- to 8-in. diagonal XGA AMOLED display panels.

  9. Field Programmable Gate Array for Implementation of Redundant Advanced Digital Feedback Control

    Science.gov (United States)

    King, K. D.

    2003-01-01

    The goal of this effort was to develop a digital motor controller using field programmable gate arrays (FPGAs). This is a more rugged approach than a conventional microprocessor digital controller. FPGAs typically have higher radiation (rad) tolerance than both the microprocessor and memory required for a conventional digital controller. Furthermore, FPGAs can typically operate at higher speeds. (While speed is usually not an issue for motor controllers, it can be for other system controllers.) Other than motor power, only a 3.3-V digital power supply was used in the controller; no analog bias supplies were used. Since most of the circuit was implemented in the FPGA, no additional parts were needed other than the power transistors to drive the motor. The benefits that FPGAs provide over conventional designs-lower power and fewer parts-allow for smaller packaging and reduced weight and cost.

  10. Development of digital sideband separating down-conversion for Yuan-Tseh Lee Array

    Science.gov (United States)

    Li, Chao-Te; Kubo, Derek; Cheng, Jen-Chieh; Kuroda, John; Srinivasan, Ranjani; Ho, Solomon; Guzzino, Kim; Chen, Ming-Tang

    2016-07-01

    This report presents a down-conversion method involving digital sideband separation for the Yuan-Tseh Lee Array (YTLA) to double the processing bandwidth. The receiver consists of a MMIC HEMT LNA front end operating at a wavelength of 3 mm, and sub-harmonic mixers that output signals at intermediate frequencies (IFs) of 2-18 GHz. The sideband separation scheme involves an analog 90° hybrid followed by two mixers that provide down-conversion of the IF signal to a pair of in-phase (I) and quadrature (Q) signals in baseband. The I and Q baseband signals are digitized using 5 Giga sample per second (Gsps) analog-to-digital converters (ADCs). A second hybrid is digitally implemented using field-programmable gate arrays (FPGAs) to produce two sidebands, each with a bandwidth of 1.6 GHz. The 2 x 1.6 GHz band can be tuned to cover any 3.6 GHz window within the aforementioned IF range of the array. Sideband rejection ratios (SRRs) above 20 dB can be obtained across the 3.6 GHz bandwidth by equalizing the power and delay between the I and Q baseband signals. Furthermore, SRRs above 30 dB can be achieved when calibration is applied.

  11. Development of analog-digital readout integrated circuits for infrared focal plane arrays

    Science.gov (United States)

    Dem'yanenko, M. A.; Kozlov, A. I.; Marchishin, I. V.; Ovsyuk, V. N.

    2016-11-01

    This paper describes the design of readout integrated circuits (ROICs) for hybrid infrared focal plane arrays (IR FPAs). This work contains the estimation of the noise equivalent temperature difference (NETD) of IR FPAs based on frame and row integration of pixel signals in the spectral ranges of 8 to 14 and 3 to 5 μm. This paper also describes the development of ROICs for IR FPAs created with the use of mercury—cadmium—telluride (MCT) photodiodes and quantum well infrared photodetectors (QWIPs). The designed ROICs ensure the use of matrix and linear photodetector chips, including those with increased dark currents, in order to produce IR FPAs with temperature resolution corresponding to the world level of array analogs.

  12. Amorphous In–Ga–Zn–O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronic Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-09-15

    Purpose: The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67–3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In–Ga–Zn–O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. Methods: The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. Results: The result demonstrates that a large charge gain of 31–122 is achieved for the proposed high-mobility (5–20 cm{sup 2}/V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (<10{sup −13} A) and OPD (<10{sup −8} A/cm{sup 2}) leakage currents can further reduce the APS noise. Cascaded system analysis shows that the proposed APS imager with a 75 μm pixel pitch can effectively resolve the Nyquist frequency of 6.67 lp/mm, which can be further improved to ∼10 lp/mm if the pixel pitch is reduced to 50 μm. Moreover, the

  13. Digital cell counting device integrated with a single-cell array.

    Science.gov (United States)

    Saeki, Tatsuya; Hosokawa, Masahito; Lim, Tae-kyu; Harada, Manabu; Matsunaga, Tadashi; Tanaka, Tsuyoshi

    2014-01-01

    In this paper, we present a novel cell counting method accomplished using a single-cell array fabricated on an image sensor, complementary metal oxide semiconductor sensor. The single-cell array was constructed using a microcavity array, which can trap up to 7,500 single cells on microcavities periodically arranged on a plane metallic substrate via the application of a negative pressure. The proposed method for cell counting is based on shadow imaging, which uses a light diffraction pattern generated by the microcavity array and trapped cells. Under illumination, the cell-occupied microcavities are visualized as shadow patterns in an image recorded by the complementary metal oxide semiconductor sensor due to light attenuation. The cell count is determined by enumerating the uniform shadow patterns created from one-on-one relationships with single cells trapped on the microcavities in digital format. In the experiment, all cell counting processes including entrapment of non-labeled HeLa cells from suspensions on the array and image acquisition of a wide-field-of-view of 30 mm(2) in 1/60 seconds were implemented in a single integrated device. As a result, the results from the digital cell counting had a linear relationship with those obtained from microscopic observation (r(2)  = 0.99). This platform could be used at extremely low cell concentrations, i.e., 25-15,000 cells/mL. Our proposed system provides a simple and rapid miniaturized cell counting device for routine laboratory use.

  14. Digitization

    DEFF Research Database (Denmark)

    Finnemann, Niels Ole

    2014-01-01

    Processes of digitization have for years represented a major trend in the developments of modern society but have only recently been related to processes of mediatization. The purpose of this article is to look into the relation between the concepts of mediatization and digitization and to clarify...... what a concept of digital media might add to the understanding of processes of mediatization and what the concept of mediatization might add to the understanding of digital media. It is argued that digital media open an array of new trajectories in human communication, trajectories which were...... not anticipated in previous conceptualizations of media and mediatization. If digital media are to be included, the concept of mediatization has to be revised and new parameters are to be built into the concept of media. At the same time it is argued that the concept of mediatization still provides a variety...

  15. Pixel Experiments

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Augustesen, Christina

    2015-01-01

    Pixel Experiments The term pixel is traditionally defined as any of the minute elements that together constitute a larger context or image. A pixel has its own form and is the smallest unit seen within a larger structure. In working with the potentials of LED technology in architectural lighting...... design it became relevant to investigate the use of LEDs as the physical equivalent of a pixel as a design approach. In this book our interest has been in identifying how the qualities of LEDs can be used in lighting applications. With experiences in the planning and implementation of architectural...... elucidate and exemplify already well-known problems in relation to the experience of vertical and horizontal lighting. Pixel Experiments exist as a synergy between speculative test setups and lighting design in practice. This book is one of four books that is published in connection with the research...

  16. Application of bistable optical logic gate arrays to all-optical digital parallel processing

    Science.gov (United States)

    Walker, A. C.

    1986-05-01

    Arrays of bistable optical gates can form the basis of an all-optical digital parallel processor. Two classes of signal input geometry exist - on- and off-axis - and lead to distinctly different device characteristics. The optical implementation of multisignal fan-in to an array of intrinsically bistable optical gates using the more efficient off-axis option is discussed together with the construction of programmable read/write memories from optically bistable devices. Finally the design of a demonstration all-optical parallel processor incorporating these concepts is presented.

  17. Diode-array UV solar spectroradiometer implementing a digital micromirror device

    Science.gov (United States)

    Feldman, A.; Burnitt, T.; Porrovecchio, G.; Smid, M.; Egli, L.; Gröbner, J.; Nield, K. M.

    2014-12-01

    The solar ultraviolet spectrum captured by commercially available diode-array spectroradiometers is dominated by stray light from longer wavelengths with higher intensity. The implementation of a digital micromirror device in an array spectroradiometer has the potential to enable the precise selection of desired wavelengths as well as the ability to reduce spectral intensity of some wavelengths via selective mirror modulation, both reducing long wavelength stray light. A prototype consisting of off-the-shelf components has been assembled to verify the validity of the base concept, and initial measurements have been performed to confirm the throughput and image qualities such as spectral resolution and astigmatism.

  18. Interference mitigation for simultaneous transmit and receive applications on digital phased array systems

    Science.gov (United States)

    Snow, Trevor M.

    As analog-to-digital (ADC) and digital-to-analog conversion (DAC) technologies become cheaper and digital processing capabilities improve, phased array systems with digital transceivers at every element will become more commonplace. These architectures offer greater capability over traditional analog systems and enable advanced applications such as multiple-input, multiple-output (MIMO) communications, adaptive beamforming, space-time adaptive processing (STAP), and MIMO for radar. Capabilities for such systems are still limited by the need for isolating self-interference from transmitters at co-located receivers. The typical approach of time-sharing the antenna aperture between transmitters and receivers works but leaves the receivers blind for a period of time. For full-duplex operation, some systems use separate frequency bands for transmission and reception, but these require fixed filtering which reduces the system's ability to adapt to its environment and is also an inefficient use of spectral resources. To that end, tunable, high quality-factor filters are used for sub-band isolation and protect receivers while allowing open reception at other frequencies. For more flexibility, another emergent area of related research has focused on co-located spatial isolation using multiple antennas and direct injection of interference cancellation signals into receivers, which enables same-frequency full-duplex operation. With all these methods, self-interference must be reduced by an amount that prevents saturation of the ADC. Intermodulation products generated in the receiver in this process can potentially be problematic, as certain intermodulation products may appear to come from a particular angle and cohere in the beamformer. This work explores various digital phased array architectures and the how the flexibility afforded by an all-digital beamforming architecture, layered with other methods of isolation, can be used to reduce self-interference within the system

  19. FE-I4 Chip Development for Upgraded ATLAS Pixel Detector at LHC

    CERN Document Server

    Barbero, M; The ATLAS collaboration

    2010-01-01

    A new ATLAS pixel chip FE-I4 has been developed for use in upgraded LHC luminosity environments, including the near-term Insertable B-Layer upgrade. FE-I4 is designed in a 130 nm CMOS technology, presenting advantages in terms of radiation tolerance and digital logic density compared to the 0.25 μm CMOS technology used for the current ATLAS pixel IC, FE-I3. FE-I4 architecture is based on an array of 80×336 pixels, each 50×250 μm2, consisting of analog and digital sections. The analog pixel section is designed for low power consumption and compatibility to several sensor candidates. It is based on a two-stage architecture with a pre-amp AC-coupled to a second stage of amplification. It features leakage current compensation circuitry, local 4-bit pre-amp feedback tuning and a discriminator locally adjusted through 5 configuration bits. The digital architecture is based on a 4-pixel unit called Pixel Digital Region (PDR) allowing for local storage of hits in 5-deep data buffers at pixel level for the duratio...

  20. FlashCam: A fully digital camera for the Cherenkov Telescope Array

    CERN Document Server

    Pühlhofer, G; Eisenkolb, F; Florin, D; Föhr, C; Gadola, A; Hermann, G; Kalkuhl, C; Kasperek, J; Kihm, T; Koziol, J; Manalaysay, A; Marszalek, A; Rajda, P J; Romaszkan, W; Rupinski, M; Schanz, T; Steiner, S; Straumann, U; Tenzer, C; Vollhardt, A; Weitzel, Q; Winiarski, K; Zietara, K

    2013-01-01

    FlashCam is a Cherenkov camera development project centered around a fully digital trigger and readout scheme with smart, digital signal processing, and a "horizontal" architecture for the electromechanical implementation. The fully digital approach, based on commercial FADCs and FPGAs as key components, provides the option to easily implement different types of triggers as well as digitization and readout scenarios using identical hardware, by simply changing the firmware on the FPGAs. At the same time, a large dynamic range and high resolution of low-amplitude signals in a single readout channel per pixel is achieved using compression of high amplitude signals in the preamplifier and signal processing in the FPGA. The readout of the front-end modules into a camera server is Ethernet-based using standard Ethernet switches. In its current implementation, data transfer and backend processing rates of ~3.8 GBytes/sec have been achieved. Together with the dead-time-free front end event buffering on the FPGAs, th...

  1. Wideband aperture array using RF channelizers and massively parallel digital 2D IIR filterbank

    Science.gov (United States)

    Sengupta, Arindam; Madanayake, Arjuna; Gómez-García, Roberto; Engeberg, Erik D.

    2014-05-01

    Wideband receive-mode beamforming applications in wireless location, electronically-scanned antennas for radar, RF sensing, microwave imaging and wireless communications require digital aperture arrays that offer a relatively constant far-field beam over several octaves of bandwidth. Several beamforming schemes including the well-known true time-delay and the phased array beamformers have been realized using either finite impulse response (FIR) or fast Fourier transform (FFT) digital filter-sum based techniques. These beamforming algorithms offer the desired selectivity at the cost of a high computational complexity and frequency-dependant far-field array patterns. A novel approach to receiver beamforming is the use of massively parallel 2-D infinite impulse response (IIR) fan filterbanks for the synthesis of relatively frequency independent RF beams at an order of magnitude lower multiplier complexity compared to FFT or FIR filter based conventional algorithms. The 2-D IIR filterbanks demand fast digital processing that can support several octaves of RF bandwidth, fast analog-to-digital converters (ADCs) for RF-to-bits type direct conversion of wideband antenna element signals. Fast digital implementation platforms that can realize high-precision recursive filter structures necessary for real-time beamforming, at RF radio bandwidths, are also desired. We propose a novel technique that combines a passive RF channelizer, multichannel ADC technology, and single-phase massively parallel 2-D IIR digital fan filterbanks, realized at low complexity using FPGA and/or ASIC technology. There exists native support for a larger bandwidth than the maximum clock frequency of the digital implementation technology. We also strive to achieve More-than-Moore throughput by processing a wideband RF signal having content with N-fold (B = N Fclk/2) bandwidth compared to the maximum clock frequency Fclk Hz of the digital VLSI platform under consideration. Such increase in bandwidth is

  2. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  3. Digital data acquisition for the Low Energy Neutron Detector Array (LENDA)

    Energy Technology Data Exchange (ETDEWEB)

    Lipschutz, S., E-mail: lipschutz@nscl.msu.edu [Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States); National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics Center for the Evolution of the Elements, Michigan State University, East Lansing, MI (United States); Zegers, R.G.T.; Hill, J. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States); National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics Center for the Evolution of the Elements, Michigan State University, East Lansing, MI (United States); Liddick, S.N. [National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Noji, S., E-mail: noji@rcnp.osaka-u.ac.jp [National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics Center for the Evolution of the Elements, Michigan State University, East Lansing, MI (United States); Prokop, C.J. [National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Scott, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States); National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics Center for the Evolution of the Elements, Michigan State University, East Lansing, MI (United States); Solt, M., E-mail: mrsolt@stanford.edu [National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics Center for the Evolution of the Elements, Michigan State University, East Lansing, MI (United States); Department of Physics, Oakland University, Rochester, MI (United States); and others

    2016-04-11

    A digital data acquisition system (DDAS) has been implemented for the Low Energy Neutron Detector Array (LENDA). LENDA is an array of 24 BC-408 plastic-scintillator bars designed to measure low-energy neutrons with kinetic energies in the range of 100 keV–10 MeV from (p,n)-type charge-exchange reactions. Compared to the previous data acquisition (DAQ) system for LENDA, DDAS offers the possibility to lower the neutron detection threshold, increase the overall neutron-detection efficiency, decrease the dead time of the system, and allow for easy expansion of the array. The system utilized in this work was XIA's Digital Gamma Finder Pixie-16 250 MHz digitizers. A detector-limited timing resolution of 400 ps was achieved for a single LENDA bar. Using DDAS, the neutron detection threshold of the system was reduced compared to the previous analog system, now reaching below 100 keV. The new DAQ system was successfully used in a recent charge-exchange experiment using the {sup 16}C(p,n) reaction at the National Superconducting Cyclotron Laboratory (NSCL).

  4. Digital Data Acquisition For the Low Energy Neutron Detector Array (LENDA)

    CERN Document Server

    Lipschutz, S; Hill, J; Liddick, S N; Noji, S; Prokop, C J; Scott, M; Solt, M; Sullivan, C; Tompkins, J

    2016-01-01

    A digital data acquisition system (DDAS) has been implemented for the Low Energy Neutron Detector Array (LENDA). LENDA is an array of 24 BC-408 plastic-scintillator bars designed to measure low-energy neutrons with kinetic energies in the range of 100 keV to 10 MeV from (p,n)-type charge-exchange reactions. Compared to the previous data acquisition (DAQ) system for LENDA, DDAS offers the possibility to lower the neutron detection threshold, increase the overall neutron-detection efficiency, decrease the dead time of the system, and allow for easy expansion of the array. The system utilized in this work was XIA's Digital Gamma Finder Pixie-16 250 MHz digitizers. A detector-limited timing resolution of 400 ps was achieved for a single LENDA bar. Using DDAS, the neutron detection threshold of the system was reduced compared to the previous analog system, now reaching below 100 keV. The new DAQ system was successfully used in a recent charge-exchange experiment using the $^{16}$C(p,n) reaction at the National Sup...

  5. A data parallel digitizer for a time-based simulation of CMOS Monolithic Active Pixel Sensors with FairRoot

    Science.gov (United States)

    Sitzmann, P.; Amar-Youcef, S.; Doering, D.; Deveaux, M.; Fröhlich, I.; Koziel, M.; Krebs, E.; Linnik, B.; Michel, J.; Milanovic, B.; Müntz, C.; Li, Q.; Stroth, J.; Tischler, T.

    2014-06-01

    CMOS Monolithic Active Pixel Sensors (MAPS) demonstrated excellent performances in the field of charged particle tracking. They feature an excellent single point resolution of few μm, a light material budget of 0.05% Xo in combination with a good radiation tolerance and time resolution. This makes the sensors a valuable technology for micro vertex detectors (MVD) of various experiments in heavy ion and particle physics like STAR and CBM. State of the art MAPS are equipped with a rolling shutter readout. Therefore, the data of one individual event is typically found in more than one data train generated by the sensor. This paper presents a concept to introduce this feature in both simulation and data analysis, taking profit of the sensor topology of the MVD. This topology allows to use for massive parallel data streaming and handling strategies within the FairRoot framework.

  6. The european FAZIA initiative: a high-performance digital telescope array for heavy-ion studies

    CERN Document Server

    Casini, G; Pasquali, G; Pastore, G; Bini, M; Carboni, S; Olmi, A; Piantelli, S; Poggi, G; Stefanini, A; Valdre', S; Bonnet, E; Borderie, B; Bougault, R; Bruno, M; Chbihi, A; Cinausero, M; Degerlier, M; Edelbruck, P; Frankland, J D; Gramegna, F; Gruyer, D; Guerzoni, M; Kordjasz, A; Kozik, T; Neindre, N Le; Lopez, O; Marchi, T; Marini, P; Morelli, L; Ordine, A; Parlog, M; Rivet, M F; Rosato, E; Salomon, F; Spadaccini, G; Twarog, T; Vient, E; Vigilante, M

    2013-01-01

    The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification also via pulse shape analysis. The achievement of top performances imposes specific electronics which has been developed by FAZIA and features high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program centered on experiments to be done with the demonstrator. First results on the isospin dynamics obt...

  7. Note: application of a pixel-array area detector to simultaneous single crystal X-ray diffraction and X-ray absorption spectroscopy measurements.

    Science.gov (United States)

    Sun, Cheng-Jun; Zhang, Bangmin; Brewe, Dale L; Chen, Jing-Sheng; Chow, G M; Venkatesan, T; Heald, Steve M

    2014-04-01

    X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr0.67Sr0.33MnO3 film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.

  8. A High-Speed CMOS Image Sensor with Global Electronic Shutter Pixels Using Pinned Diodes

    Science.gov (United States)

    Yasutomi, Keita; Tamura, Toshihiro; Furuta, Masanori; Itoh, Shinya; Kawahito, Shoji

    This paper describes a high-speed CMOS image sensor with a new type of global electronic shutter pixel. A global electronic shutter is necessary for imaging fast-moving objects without motion blur or distortion. The proposed pixel has two potential wells with pinned diode structure for two-stage charge transfer that enables a global electronic shuttering and reset noise canceling. A prototype high-speed image sensor fabricated in 0.18μm standard CMOS image sensor process consists of the proposed pixel array, 12-bit column-parallel cyclic ADC arrays and 192-channel digital outputs. The sensor achieves a good linearity at low-light intensity, demonstrating the perfect charge transfer between two pinned diodes. The input referred noise of the proposed pixel is measured to be 6.3 e-.

  9. High-resolution focal plane array IR detection modules and digital signal processing technologies at AIM

    Science.gov (United States)

    Cabanski, Wolfgang A.; Breiter, Rainer; Koch, R.; Mauk, Karl-Heinz; Rode, Werner; Ziegler, Johann; Eberhardt, Kurt; Oelmaier, Reinhard; Schneider, Harald; Walther, Martin

    2000-07-01

    Full video format focal plane array (FPA) modules with up to 640 X 512 pixels have been developed for high resolution imaging applications in either mercury cadmium telluride (MCT) mid wave (MWIR) infrared (IR) or platinum silicide (PtSi) and quantum well infrared photodetector (QWIP) technology as low cost alternatives to MCT for high performance IR imaging in the MWIR or long wave spectral band (LWIR). For the QWIP's, a new photovoltaic technology was introduced for improved NETD performance and higher dynamic range. MCT units provide fast frame rates > 100 Hz together with state of the art thermal resolution NETD rates of 30 - 60 Hz and provide thermal resolutions of NETD exchangeability of the units. New modular image processing hardware platforms and software for image visualization and nonuniformity correction including scene based self learning algorithms had to be developed to accomplish for the high data rates of up to 18 M pixels/s with 14-bit deep data, allowing to take into account nonlinear effects to access the full NETD by accurate reduction of residual fixed pattern noise. The main features of these modules are summarized together with measured performance data for long range detection systems with moderately fast to slow F-numbers like F/2.0 - F/3.5. An outlook shows most recent activities at AIM, heading for multicolor and faster frame rate detector modules based on MCT devices.

  10. Digital cell counting device integrated with a single-cell array.

    Directory of Open Access Journals (Sweden)

    Tatsuya Saeki

    Full Text Available In this paper, we present a novel cell counting method accomplished using a single-cell array fabricated on an image sensor, complementary metal oxide semiconductor sensor. The single-cell array was constructed using a microcavity array, which can trap up to 7,500 single cells on microcavities periodically arranged on a plane metallic substrate via the application of a negative pressure. The proposed method for cell counting is based on shadow imaging, which uses a light diffraction pattern generated by the microcavity array and trapped cells. Under illumination, the cell-occupied microcavities are visualized as shadow patterns in an image recorded by the complementary metal oxide semiconductor sensor due to light attenuation. The cell count is determined by enumerating the uniform shadow patterns created from one-on-one relationships with single cells trapped on the microcavities in digital format. In the experiment, all cell counting processes including entrapment of non-labeled HeLa cells from suspensions on the array and image acquisition of a wide-field-of-view of 30 mm(2 in 1/60 seconds were implemented in a single integrated device. As a result, the results from the digital cell counting had a linear relationship with those obtained from microscopic observation (r(2  = 0.99. This platform could be used at extremely low cell concentrations, i.e., 25-15,000 cells/mL. Our proposed system provides a simple and rapid miniaturized cell counting device for routine laboratory use.

  11. Array microscopy technology and its application to digital detection of Mycobacterium tuberculosis

    Science.gov (United States)

    McCall, Brian P.

    Tuberculosis causes more deaths worldwide than any other curable infectious disease. This is the case despite tuberculosis appearing to be on the verge of eradication midway through the last century. Efforts at reversing the spread of tuberculosis have intensified since the early 1990s. Since then, microscopy has been the primary frontline diagnostic. In this dissertation, advances in clinical microscopy towards array microscopy for digital detection of Mycobacterium tuberculosis are presented. Digital array microscopy separates the tasks of microscope operation and pathogen detection and will reduce the specialization needed in order to operate the microscope. Distributing the work and reducing specialization will allow this technology to be deployed at the point of care, taking the front-line diagnostic for tuberculosis from the microscopy center to the community health center. By improving access to microscopy centers, hundreds of thousands of lives can be saved. For this dissertation, a lens was designed that can be manufactured as 4x6 array of microscopes. This lens design is diffraction limited, having less than 0.071 waves of aberration (root mean square) over the entire field of view. A total area imaged onto a full-frame digital image sensor is expected to be 3.94 mm2, which according to tuberculosis microscopy guidelines is more than sufficient for a sensitive diagnosis. The design is tolerant to single point diamond turning manufacturing errors, as found by tolerance analysis and by fabricating a prototype. Diamond micro-milling, a fabrication technique for lens array molds, was applied to plastic plano-concave and plano-convex lens arrays, and found to produce high quality optical surfaces. The micro-milling technique did not prove robust enough to produce bi-convex and meniscus lens arrays in a variety of lens shapes, however, and it required lengthy fabrication times. In order to rapidly prototype new lenses, a new diamond machining technique was

  12. Application of neural networks to digital pulse shape analysis for an array of silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Flores, J.L. [Dpto de Ingeniería Eléctrica y Térmica, Universidad de Huelva (Spain); Martel, I. [Dpto de Física Aplicada, Universidad de Huelva (Spain); CERN, ISOLDE, CH 1211 Geneva, 23 (Switzerland); Jiménez, R. [Dpto de Ingeniería Electrónica, Sist. Informáticos y Automática, Universidad de Huelva (Spain); Galán, J., E-mail: jgalan@diesia.uhu.es [Dpto de Ingeniería Electrónica, Sist. Informáticos y Automática, Universidad de Huelva (Spain); Salmerón, P. [Dpto de Ingeniería Eléctrica y Térmica, Universidad de Huelva (Spain)

    2016-09-11

    The new generation of nuclear physics detectors that used to study nuclear reactions is considering the use of digital pulse shape analysis techniques (DPSA) to obtain the (A,Z) values of the reaction products impinging in solid state detectors. This technique can be an important tool for selecting the relevant reaction channels at the HYDE (HYbrid DEtector ball array) silicon array foreseen for the Low Energy Branch of the FAIR facility (Darmstadt, Germany). In this work we study the feasibility of using artificial neural networks (ANNs) for particle identification with silicon detectors. Multilayer Perceptron networks were trained and tested with recent experimental data, showing excellent identification capabilities with signals of several isotopes ranging from {sup 12}C up to {sup 84}Kr, yielding higher discrimination rates than any other previously reported.

  13. Application of neural networks to digital pulse shape analysis for an array of silicon strip detectors

    Science.gov (United States)

    Flores, J. L.; Martel, I.; Jiménez, R.; Galán, J.; Salmerón, P.

    2016-09-01

    The new generation of nuclear physics detectors that used to study nuclear reactions is considering the use of digital pulse shape analysis techniques (DPSA) to obtain the (A,Z) values of the reaction products impinging in solid state detectors. This technique can be an important tool for selecting the relevant reaction channels at the HYDE (HYbrid DEtector ball array) silicon array foreseen for the Low Energy Branch of the FAIR facility (Darmstadt, Germany). In this work we study the feasibility of using artificial neural networks (ANNs) for particle identification with silicon detectors. Multilayer Perceptron networks were trained and tested with recent experimental data, showing excellent identification capabilities with signals of several isotopes ranging from 12C up to 84Kr, yielding higher discrimination rates than any other previously reported.

  14. Amplitude calibration of a digital radio antenna array for measuring cosmic ray air showers

    CERN Document Server

    Nehls, S; Arts, M J; Bluemer, J; Bozdog, H; van Cappellen, W A; Falcke, H; Haungs, A; Horneffer, A; Huege, T; Isar, P G; Krömer, O

    2008-01-01

    Radio pulses are emitted during the development of air showers, where air showers are generated by ultra-high energy cosmic rays entering the Earth's atmosphere. These nanosecond short pulses are presently investigated by various experiments for the purpose of using them as a new detection technique for cosmic particles. For an array of 30 digital radio antennas (LOPES experiment) an absolute amplitude calibration of the radio antennas including the full electronic chain of the data acquisition system is performed, in order to estimate absolute values of the electric field strength for these short radio pulses. This is mandatory, because the measured radio signals in the MHz frequency range have to be compared with theoretical estimates and with predictions from Monte Carlo simulations to reconstruct features of the primary cosmic particle. A commercial reference radio emitter is used to estimate frequency dependent correction factors for each single antenna of the radio antenna array. The expected received p...

  15. Focal length measurement of microlens-array by the clarity function of digital image

    Science.gov (United States)

    Zhu, Xianchang; Wu, Fan; Cao, Xuedong; Wu, Shibin; Zhang, Peng; Jing, Hongwei

    2012-10-01

    In this paper, a method for the focal length measurement of Microlens-array (MLA) is introduced. The measuring setup is composed by monochromatic, condenser, collimator, MLA, microscope and CCD sensor. An experiment was performed using a MLA whose focal length is about 8 mm and a GUI based on Matlab software was developed to analyze the image gathered at the vertex and the focus by the clarity of digital image processing technology. The measuring uncertainty of this method is about 0.8% and this method introduced in this paper can finish tens of microlens array measurement at a single shot. Compared with traditional technology for MLA measuring, this method not only has a preferable precision but also super efficiency.

  16. Development of a ground signal processor for digital synthetic array radar data

    Science.gov (United States)

    Griffin, C. R.; Estes, J. M.

    1981-01-01

    A modified APQ-102 sidelooking array radar (SLAR) in a B-57 aircraft test bed is used, with other optical and infrared sensors, in remote sensing of Earth surface features for various users at NASA Johnson Space Center. The video from the radar is normally recorded on photographic film and subsequently processed photographically into high resolution radar images. Using a high speed sampling (digitizing) system, the two receiver channels of cross-and co-polarized video are recorded on wideband magnetic tape along with radar and platform parameters. These data are subsequently reformatted and processed into digital synthetic aperture radar images with the image data available on magnetic tape for subsequent analysis by investigators. The system design and results obtained are described.

  17. A digital optical phase-locked loop for diode lasers based on field programmable gate array

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhouxiang; Zhang Xian; Huang Kaikai; Lu Xuanhui [Physics Department, Zhejiang University, Hangzhou, 310027 (China)

    2012-09-15

    We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad{sup 2} and transition time of 100 {mu}s under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.

  18. Miniature objective lens for array digital pathology: design improvement based on clinical evaluation

    Science.gov (United States)

    McCall, Brian; Pierce, Mark; Graviss, Edward A.; Richards-Kortum, Rebecca R.; Tkaczyk, Tomasz S.

    2016-03-01

    A miniature objective designed for digital detection of Mycobacterium tuberculosis (MTB) was evaluated for diagnostic accuracy. The objective was designed for array microscopy, but fabricated and evaluated at this stage of development as a single objective. The counts and diagnoses of patient samples were directly compared for digital detection and standard microscopy. The results were found to be correlated and highly concordant. The evaluation of this lens by direct comparison to standard fluorescence sputum smear microscopy presented unique challenges and led to some new insights in the role played by the system parameters of the microscope. The design parameters and how they were developed are reviewed in light of these results. New system parameters are proposed with the goal of easing the challenges of evaluating the miniature objective and maintaining the optical performance that produced the agreeable results presented without over-optimizing. A new design is presented that meets and exceeds these criteria.

  19. Processing of A New Digital Orthoimage Map of The Martian Western Hemisphere Using Data Obtained From The Mars Orbiter Camera At A Resolution of 256 Pixel/deg

    Science.gov (United States)

    Wählisch, M.; Niedermaier, G.; van Gasselt, S.; Scholten, F.; Wewel, F.; Roatsch, T.; Matz, K.-D.; Jaumann, R.

    We present a new digital orthoimage map of Mars using data obtained from the CCD line scanner Mars Orbiter Camera (MOC) of the Mars Global Surveyor Mis- sion (MGS) [1,2]. The map covers the Mars surface from 0 to 180 West and from 60 South to 60 North with the MDIM2 resolution of 256 pixel/degree and size. Image data processing has been performed using multiple programs, developed by DLR, Technical University of Berlin [3], JPL, and the USGS. 4,339 Context and 183 Geodesy images [2] were included. After radiometric corrections, the images were Mars referenced [4], geometrically corrected [5] and orthoprojected using a global Martian Digital Terrain Model (DTM) with a resolution of 64 pixel/degree, developed at DLR and based on MGS Mars Orbiter Laser Altimeter (MOLA) data [6]. To elim- inate major differences in brightness between the individual images of the mosaics, high- and low-pass filter processing techniques were applied for each image. After filtering, the images were mosaicked without registering or using block adjustment techniques in order to improve the geometric quality. It turns out that the accuracy of the navigation data has such a good quality that the orthoimages fit very well to each other. When merging the MOC mosaic with the MOLA data using IHS- trans- formation, we recognized very good correspondence between these two datasets. We create a topographic image map of the Coprates region (MC­18) adding contour lines derived from the global DTM to the mosaic. These maps are used for geological and morphological interpretations in order to review and improve our current Viking-based knowledge about the Martian surface. References: [1] www.mssss.com, [2] Caplinger, M. and M. Malin, "The Mars Or- biter Camera Geodesy Campaign, JGR, in press, [3] Scholten, F., Vol XXXI, Part B2, Wien 1996, p.351-356, [4] naïf.jpl.nasa.gov, [5] R.L.Kirk. et al. (2001), "Geometric Calibration of the Mars Orbiter Cameras and Coalignment with Mars Orbiter Laser Altimeter

  20. Digital-beamforming array antenna technologies for future ocean-observing satellite missions

    DEFF Research Database (Denmark)

    Iupikov, Oleg A.; Ivashina, Marianna V.; Cappellin, Cecilia

    2016-01-01

    Existing passive microwave radiometers that are used for ocean observations are limited in spatial resolution and geographic coverage, due to the limitations of traditional antenna technologies using mechanically-scanning reflectors and horn-type feeds. Future ocean observation missions call...... for new solutions, such as digitally-beamforming array feeds (DBAFs) as well as stationary and more complex reflectors. Our studies demonstrate that DBAFs can overcome the physically fundamental limitations of traditional horn feeds, and are capable of meeting all the challenging requirements for the next...

  1. Digital pulse-timing technique for the neutron detector array NEDA

    Energy Technology Data Exchange (ETDEWEB)

    Modamio, V., E-mail: victor.modamio@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Valiente-Dobón, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Jaworski, G. [Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa (Poland); Heavy Ion Laboratory, University of Warsaw, 02-093 Warszawa (Poland); Hüyük, T. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Triossi, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Egea, J. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Department of Electronic Engineering, Universitat de València, E-46100 Burjassot (Spain); Di Nitto, A. [Johannes Gutenberg-Universität Mainz, D-55099 Mainz (Germany); Söderström, P.-A. [RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, 351-0198 Saitama (Japan); Agramunt Ros, J. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Angelis, G. de [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); France, G. de [GANIL, CEA/DSAM and CNRS/IN2P3, F-14076 Caen (France); Erduran, M.N. [Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, 34303 Istanbul (Turkey); and others

    2015-03-01

    A new digital pulse-timing algorithm, to be used with the future neutron detector array NEDA, has been developed and tested. The time resolution of four 5 in. diameter photomultiplier tubes (XP4512, R4144, R11833-100, and ET9390-kb), coupled to a cylindrical 5 in. by 5 in. BC501A liquid scintillator detector was measured by employing digital sampling electronics and a constant fraction discriminator (CFD) algorithm. The zero crossing of the CFD algorithm was obtained with a cubic spline interpolation, which was continuous up to the second derivative. The performance of the algorithm was studied at sampling rates of 500 MS/s and 200 MS/s. The time resolution obtained with the digital electronics was compared to the values acquired with a standard analog CFD. The result of this comparison shows that the time resolution from the analog and the digital measurements at 500 MS/s and at 200 MS/s are within 15% for all the tested photomultiplier tubes.

  2. TARGET: A Digitizing And Trigger ASIC For The Cherenkov Telescope Array

    CERN Document Server

    Funk, S; Katagiri, H; Kraus, M; Okumura, A; Schoorlemmer, H; Shigenaka, A; Tajima, H; Tibaldo, L; Varner, G; Zink, A; Zorn, J

    2016-01-01

    The future ground-based gamma-ray observatory Cherenkov Telescope Array (CTA) will feature multiple types of imaging atmospheric Cherenkov telescopes, each with thousands of pixels. To be affordable, camera concepts for these telescopes have to feature low cost per channel and at the same time meet the requirements for CTA in order to achieve the desired scientific goals. We present the concept of the TeV Array Readout Electronics with GSa/s sampling and Event Trigger (TARGET) Application Specific Circuit (ASIC), envisaged to be used in the cameras of various CTA telescopes, e.g. the Gamma-ray Cherenkov Telescope (GCT), a proposed 2-Mirror Small-Sized Telescope, and the Schwarzschild-Couder Telescope (SCT), a proposed Medium-Sized Telescope. In the latest version of this readout concept the sampling and trigger parts are split into dedicated ASICs, TARGET C and T5TEA, both providing 16 parallel input channels. TARGET C features a tunable sampling rate (usually 1 GSa/s), a 16k sample deep buffer for each chann...

  3. Fast Imaging Detector Readout Circuits with In-Pixel ADCs for Fourier Transform Imaging Spectrometers

    Science.gov (United States)

    Rider, D.; Blavier, J-F.; Cunningham, T.; Hancock, B.; Key, R.; Pannell, Z.; Sander, S.; Seshadri, S.; Sun, C.; Wrigley, C.

    2011-01-01

    Focal plane arrays (FPAs) with high frame rates and many pixels benefit several upcoming Earth science missions including GEO-CAPE, GACM, and ACE by enabling broader spatial coverage and higher spectral resolution. FPAs for the PanFTS, a high spatial resolution Fourier transform spectrometer and a candidate instrument for the GEO-CAPE mission are the focus of the developments reported here, but this FPA technology has the potential to enable a variety of future measurements and instruments. The ESTO ACT Program funded the developed of a fast readout integrated circuit (ROIC) based on an innovative in-pixel analog-to-digital converter (ADC). The 128 X 128 pixel ROIC features 60 ?m pixels, a 14-bit ADC in each pixel and operates at a continuous frame rate of 14 kHz consuming only 1.1 W of power. The ROIC outputs digitized data completely eliminating the bulky, power consuming signal chains needed by conventional FPAs. The 128 X 128 pixel ROIC has been fabricated in CMOS and tested at the Jet Propulsion Laboratory. The current version is designed to be hybridized with PIN photodiode arrays via indium bump bonding for light detection in the visible and ultraviolet spectral regions. However, the ROIC design incorporates a small photodiode in each cell to permit detailed characterization of the ROICperformance without the need for hybridization. We will describe the essential features of the ROIC design and present results of ROIC performance measurements.

  4. Fast Imaging Detector Readout Circuits with In-Pixel ADCs for Fourier Transform Imaging Spectrometers

    Science.gov (United States)

    Rider, D.; Blavier, J-F.; Cunningham, T.; Hancock, B.; Key, R.; Pannell, Z.; Sander, S.; Seshadri, S.; Sun, C.; Wrigley, C.

    2011-01-01

    Focal plane arrays (FPAs) with high frame rates and many pixels benefit several upcoming Earth science missions including GEO-CAPE, GACM, and ACE by enabling broader spatial coverage and higher spectral resolution. FPAs for the PanFTS, a high spatial resolution Fourier transform spectrometer and a candidate instrument for the GEO-CAPE mission are the focus of the developments reported here, but this FPA technology has the potential to enable a variety of future measurements and instruments. The ESTO ACT Program funded the developed of a fast readout integrated circuit (ROIC) based on an innovative in-pixel analog-to-digital converter (ADC). The 128 X 128 pixel ROIC features 60 ?m pixels, a 14-bit ADC in each pixel and operates at a continuous frame rate of 14 kHz consuming only 1.1 W of power. The ROIC outputs digitized data completely eliminating the bulky, power consuming signal chains needed by conventional FPAs. The 128 X 128 pixel ROIC has been fabricated in CMOS and tested at the Jet Propulsion Laboratory. The current version is designed to be hybridized with PIN photodiode arrays via indium bump bonding for light detection in the visible and ultraviolet spectral regions. However, the ROIC design incorporates a small photodiode in each cell to permit detailed characterization of the ROICperformance without the need for hybridization. We will describe the essential features of the ROIC design and present results of ROIC performance measurements.

  5. Design of DSP-based high-power digital solar array simulator

    Science.gov (United States)

    Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

    2013-12-01

    To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

  6. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  7. The european FAZIA initiative: a high-performance digital telescope array for heavy-ion studies

    Science.gov (United States)

    Casini, G.; Barlini, S.; Pasquali, G.; Pastore, G.; Bini, M.; Carboni, S.; Olmi, A.; Piantelli, S.; Poggi, G.; Stefanini, A.; Valdré, S.; Bonnet, E.; Borderie, B.; Bougault, R.; Bruno, M.; Chbihi, A.; Cinausero, M.; Degerlier, M.; Edelbruck, P.; Frankland, J. D.; Gramegna, F.; Gruyer, D.; Guerzoni, M.; Kordjasz, A.; Kozik, T.; Le Neindre, N.; Lopez, O.; Marchi, T.; Marini, P.; Morelli, L.; Ordine, A.; Pârlog, M.; Rivet, M. F.; Rosato, E.; Salomon, F.; Spadaccini, G.; Twaróg, T.; Vient, E.; Vigilante, M.

    2014-03-01

    The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification including pulse shape analysis, too. The achievement of top performances imposes specific electronics which has been developed by the FAZIA collaboration and includes high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program focused on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams.

  8. The european FAZIA initiative: a high-performance digital telescope array for heavy-ion studies

    Directory of Open Access Journals (Sweden)

    Casini G.

    2014-03-01

    Full Text Available The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification including pulse shape analysis, too. The achievement of top performances imposes specific electronics which has been developed by the FAZIA collaboration and includes high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program focused on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams.

  9. Direct-referencing Two-dimensional-array Digital Microfluidics Using Multi-layer Printed Circuit Board

    Science.gov (United States)

    Gong, Jian; Kim, Chang-Jin “CJ”

    2008-01-01

    Digital (i.e. droplet-based) microfluidics, by the electrowetting-on-dielectric (EWOD) mechanism, has shown great potential for a wide range of applications, such as lab-on-a-chip. While most reported EWOD chips use a series of electrode pads essentially in one-dimensional line pattern designed for specific tasks, the desired universal chips allowing user-reconfigurable paths would require the electrode pads in two-dimensional pattern. However, to electrically access the electrode pads independently, conductive lines need to be fabricated underneath the pads in multiple layers, raising a cost issue especially for disposable chip applications. In this article, we report the building of digital microfluidic plates based on a printed-circuit-board (PCB), in which multilayer electrical access lines were created inexpensively using mature PCB technology. However, due to its surface topography and roughness and resulting high resistance against droplet movement, as-fabricated PCB surfaces require unacceptably high (~500 V) voltages unless coated with or immersed in oil. Our goal is EWOD operations of aqueous droplets not only on oil-covered but also on dry surfaces. To meet varying levels of performances, three types of gradually complex post-PCB microfabrication processes are developed and evaluated. By introducing land-grid-array (LGA) sockets in the packaging, a scalable digital microfluidics system with reconfigurable and low-cost chip is also demonstrated. PMID:19234613

  10. Bump bonding of pixel systems

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, M. E-mail: manuel.lozano@cnm.es; Cabruja, E.; Collado, A.; Santander, J.; Ullan, M

    2001-11-01

    A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I/Os. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.

  11. Bump bonding of pixel systems

    CERN Document Server

    Lozano, M; Collado, A; Santander, J; Ullán, M

    2001-01-01

    A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I/Os. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.

  12. Noise Analysis of Array Pixellated CZT Detector%CZT像素阵列核探测器的噪声分析

    Institute of Scientific and Technical Information of China (English)

    蒋建; 肖沙里; 蔡欣; 张流强; 陈宇晓; 曹玉琳

    2011-01-01

    碲锌镉(CdZnTe)晶体是一种新型核辐射探测材料,在室温探测环境下对X射线及低能量伽玛射线具有较高的探测效率及能量分辨率.运用低噪声快速前放模块,分析晶体内部性能以及前置放大器对探测系统噪声的影响,建立了2×2碲锌镉像素阵列探测系统.实验结果表明,探测系统输出信号噪声小、脉冲无堆积,读出电路电子学噪声得到明显抑制,能谱低能拖尾减少,电荷收集不完全噪声及漏电流噪声影响得到改善,同时对整个系统以及前置放大器进行了噪声分析并提出相关的改善方式,最后得到系统测试的结果.%As a novel nuclear radiation material, CdZnTe has many advantages of high effi ciency detection and good energy resolution for detection of x-ray and low energy gamma-ray in room temperature. The inner crystal property and effects of preamplifier on the noise is analyzed using low noise preamplifier module, while a 2× 2 array pixellated detection system is built. The results show a low noise of output signal and no pulse stack. The circuit electronic noise is obvi ously restrained. Trails of low power of energy spectrum are decreased. Noise analysis and the factors which produced the noise are given; improvement for the system is also discussed, togeth er with the test result.

  13. Dead pixel replacement in LWIR microgrid polarimeters.

    Science.gov (United States)

    Ratliff, Bradley M; Tyo, J Scott; Boger, James K; Black, Wiley T; Bowers, David L; Fetrow, Matthew P

    2007-06-11

    LWIR imaging arrays are often affected by nonresponsive pixels, or "dead pixels." These dead pixels can severely degrade the quality of imagery and often have to be replaced before subsequent image processing and display of the imagery data. For LWIR arrays that are integrated with arrays of micropolarizers, the problem of dead pixels is amplified. Conventional dead pixel replacement (DPR) strategies cannot be employed since neighboring pixels are of different polarizations. In this paper we present two DPR schemes. The first is a modified nearest-neighbor replacement method. The second is a method based on redundancy in the polarization measurements.We find that the redundancy-based DPR scheme provides an order-of-magnitude better performance for typical LWIR polarimetric data.

  14. Fiber Bragg Grating Sensor Array System Based on Digital Phase Generated Carrier Demodulation and Reference Compensation Method

    Institute of Scientific and Technical Information of China (English)

    Jun He; Fang Li; Hao Xiao; Yu-Liang Liu

    2008-01-01

    A novel fiber Bragg grating (FBG) sensor array system based on digital phase generated carrier (PGC) demodulation and reference compensation method is proposed and set up. Experimental results confirm that the digital PGC demodulation can be used for wavelength-division-multiplexed FBG sensor array and the reference compensation method can reduce the environmental interference by approximately 40 dB in the frequency range from 20 Hz to 2 kHz. The minimum detectable wavelength-shift of the sensor system is 1×10-3 pm/Hz1/2.

  15. Silicon Avalanche Pixel Sensor for High Precision Tracking

    CERN Document Server

    D'Ascenzo, N; Moon, C S; Morsani, F; Ratti, L; Saveliev, V; Navarro, A Savoy; Xie, Q

    2013-01-01

    The development of an innovative position sensitive pixelated sensor to detect and measure with high precision the coordinates of the ionizing particles is proposed. The silicon avalanche pixel sensors (APiX) is based on the vertical integration of avalanche pixels connected in pairs and operated in coincidence in fully digital mode and with the processing electronics embedded on the chip. The APiX sensor addresses the need to minimize the material budget and related multiple scattering effects in tracking systems requiring a high spatial resolution in the presence of a large occupancy. The expected operation of the new sensor features: low noise, low power consumption and suitable radiation tolerance. The APiX device provides on-chip digital information on the position of the coordinate of the impinging charged particle and can be seen as the building block of a modular system of pixelated arrays, implementing a sparsified readout. The technological challenges are the 3D integration of the device under CMOS ...

  16. Pixel-Level Digital-to-Analog Conversion Scheme for Compact Data Drivers of Active Matrix Organic Light-Emitting Diodes with Low-Temperature Polycrystalline Silicon Thin-Film Transistors

    Science.gov (United States)

    Tae-Wook Kim,; Byong-Deok Choi,

    2010-03-01

    This paper shows that a part of a digital-to-analog conversion (DAC) function can be included in a pixel circuit to save the circuit area of an integrated data driver fabricated with low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs). Because the pixel-level DAC can be constructed by two TFTs and one small capacitor, the pixel circuit does not become markedly complex. The design of an 8-bit DAC, which combines a 6-bit resistor-string-based DAC and a 2-bit pixel-level DAC for a 4-in. diagonal VGA format active matrix organic light-emitting diode (AMOLED), is shown in detail. In addition, analysis results are presented, revealing that the 8-bit DAC scheme including a 2-bit pixel-level DAC with 1:3 demultiplexing can be applied to very high video formats, such as XGA, for a 3 to 4-in. diagonal AMOLED. Even for a 9- to 12-in. diagonal AMOLED, the proposed scheme can still be applied to the XGA format, even though no demultiplexing is allowed. The total height of the proposed 8-bit DAC is approximately 960 μm, which is almost one-half of that of the previous 6-bit resistor-string-based DAC.

  17. Pixel Design of Organic Thin Film Transistor Array%有机薄膜晶体管阵列面向电子纸像素设计

    Institute of Scientific and Technical Information of China (English)

    汪梅林; 张其国; 郑永亮; 秦永亮; 郭晓东; 潭莉; 朱棋锋; 韩学斌; 申剑锋

    2012-01-01

    As a switch device of the pixel, the Organic Thin Film Transistor(OTFT) has good IDS-VGS curve. This paper describes the pixel circuit, model parameter for HSPICE simulation and the pixel layout. In order to verify the influence of storage capacitor and TFT structure on the pixel waveform, the pixel waveform was simulated by HSPICE. The OTFT process is studied in this paper. Result shows that OTFT structure is selected according to the storage capacitor for different products. The OTFT process is suitable for flexible display.%讨论了有机薄膜晶体管(Organic Thin Film Transistor,OTFT)作为开关器件来驱动电子纸的像素设计,特别是像素电路结构、HSPICE模拟用模型参数和像素平面结构.讨论了有机薄膜晶体管制造过程,并用HSPIC模拟分析了有机薄膜晶体管结构和存贮电容大小对像素波形的影响,结果表明TFT结构的选择依赖于存贮电容的大小.

  18. A 16 channel high resolution (Digital Converter in a Field Programmable Gate Array

    Science.gov (United States)

    Ugur, C.; Bayer, E.; Kurz, N.; Traxler, M.

    2012-02-01

    A 16-channel Time-to-Digital Converter (TDC) was implemented in a general purpose Field-Programmable Gate Array (FPGA). The fine time calculations are achieved by using the dedicated carry-chain lines. The coarse counter defines the coarse time stamp. In order to overcome the negative effects of temperature and power supply dependency bin-by-bin calibration is applied. The time interval measurements are done using 2 channels. The time resolution of channels are calculated for 1 clock cycle and a minimum of 10.3 ps RMS on two channels, yielding 7.3 ps RMS (10.3 ps/√2) on a single channel is achieved.

  19. Digital Radiography and Computed Tomography Project -- Fully Integrated Linear Detector ArrayStatus Report

    Energy Technology Data Exchange (ETDEWEB)

    Tim Roney; Robert Seifert; Bob Pink; Mike Smith

    2011-09-01

    The field-portable Digital Radiography and Computed Tomography (DRCT) x-ray inspection systems developed for the Project Manager for NonStockpile Chemical Materiel (PMNSCM) over the past 13 years have used linear diode detector arrays from two manufacturers; Thomson and Thales. These two manufacturers no longer produce this type of detector. In the interest of insuring the long term viability of the portable DRCT single munitions inspection systems and to improve the imaging capabilities, this project has been investigating improved, commercially available detectors. During FY-10, detectors were evaluated and one in particular, manufactured by Detection Technologies (DT), Inc, was acquired for possible integration into the DRCT systems. The remainder of this report describes the work performed in FY-11 to complete evaluations and fully integrate the detector onto a representative DRCT platform.

  20. Digitally focused array ultrasonic testing technique for carbon fiber composite structures

    Science.gov (United States)

    Salchak, Y.; Zhvyrblya, V.; Sednev, D.; Lider, A.

    2016-06-01

    Composite fiber reinforced polymers are highly promising structures. At present, they are widely used in different areas such as aeronautics and nuclear industries. There is a great number of advantages of composite structures such as design flexibility, low cost per cubic inch, resistance to corrosion, lower material costs, lighter weight and improved productivity. However, composites degradation may be caused by different mechanisms such as overload, impact, overheating, creep and fatigue. Comparing to inspection of other materials some unique consideration is required for testing and analysis. Ultrasound testing is the most common method for inspection of composite structures. Digitally Focused Array Technology is considered as novel approach which enables fast and effective quantitative automatic testing. In this study new methodology of quality assurance of composite structure components based on DFA is performed.

  1. Centrifugal micro-channel array droplet generation for highly parallel digital PCR.

    Science.gov (United States)

    Chen, Zitian; Liao, Peiyu; Zhang, Fangli; Jiang, Mengcheng; Zhu, Yusen; Huang, Yanyi

    2017-01-17

    Stable water-in-oil emulsion is essential to digital PCR and many other bioanalytical reactions that employ droplets as microreactors. We developed a novel technology to produce monodisperse emulsion droplets with high efficiency and high throughput using a bench-top centrifuge. Upon centrifugal spinning, the continuous aqueous phase is dispersed into monodisperse droplet jets in air through a micro-channel array (MiCA) and then submerged into oil as a stable emulsion. We performed dPCR reactions with a high dynamic range through the MiCA approach, and demonstrated that this cost-effective method not only eliminates the usage of complex microfluidic devices and control systems, but also greatly suppresses the loss of materials and cross-contamination. MiCA-enabled highly parallel emulsion generation combines both easiness and robustness of picoliter droplet production, and breaks the technical challenges by using conventional lab equipment and supplies.

  2. Measurement results of a 12 μm pixel size microbolometer array based on a novel thermally isolating structure using a 17 μm ROIC

    Science.gov (United States)

    Muckensturm, K.-M.; Weiler, D.; Hochschulz, F.; Busch, C.; Geruschke, T.; Wall, S.; Heß, J.; Würfel, D.; Lerch, R.; Vogt, H.

    2016-05-01

    In this paper a novel concept for the fabrication of highly sensitive uncooled microbolometers is presented. The approach is based on the realization of thermal isolation and simultaneous electrical contacting of the microbolometers by means of sufficiently long and thin coated nanotubes, which can be fabricated by post processing on top of CMOS wafers comprising the ROIC. Thus, the effective area of the absorption layer is maximized at a given pixel size, as lateral legs, which have been the main component of the thermal isolation commonly, are completely omitted. The resulting thermal conductivity can be tuned independently from the pixel size by varying the geometry and structuring of the nanotubes. Based on test structures the nanotube microbolometers are characterized with respect to electro-optical and mechanical properties. The focus in this paper is on nanotube microbolometers with a pixel size of 12 μm.

  3. InAs/GaSb Type-II superlattice photodiode array inter-pixel region blue-shift by femtosecond (fs) laser anneal

    Science.gov (United States)

    Das, Sona; Das, Utpal

    2017-09-01

    A post-growth blue-shift in the band gap of an undoped InAs/GaSb Type-II superlattice (5.5 μm cutoff wavelength), as a result of 775 nm, 150 fs laser annealing, is presented. A band gap blue-shift of ∼72 meV in the {{{p}}}+- and p-layer etched inter-pixel region, laser annealed superlattice is achieved. Using an inter-diffusion model, the dominant group-III and group-V diffusion coefficients are found to be 1.33× {10}-21 {{{m}}}2 {{{s}}}-1 and 4.8× {10}-22 {{{m}}}2 {{{s}}}-1 respectively. Confirmation of the unaltered condition of the superlattice in a Ti/Au masked pixel area establishes this blue-shifted superlattice band gap to be the reason behind the improved inter-pixel isolation resulting from the fs laser annealing technique.

  4. Digital Calorimetry Using Pixel Sensors

    NARCIS (Netherlands)

    Reicher, M.

    2016-01-01

    The subject of this thesis is a new type of electromagnetic calorimeter, which is not based on proportionality of deposited energy, but instead on counting the number of showering particles. This calorimeter is a proof of principle for a proposed upgrade of the ALICE experiment at the Large Hadron C

  5. Digital array gas radiometer (DAGR): a sensitive and reliable trace gas detection concept

    Science.gov (United States)

    Gordley, Larry L.; McHugh, Martin J.; Marshall, B. T.; Thompson, Earl

    2009-05-01

    The Digital Array Gas Radiometer (DAGR) concept is based on traditional and reliable Gas Filter Correlation Radiometry (GFCR) for remote trace gas detection and monitoring. GFCR sensors have been successful in many infrared remote sensing applications. Historically however, solar backscatter measurements have not been as successful because instrument designs have been susceptible to natural variations in surface albedo, which induce clutter and degrade the sensitivity. DAGR overcomes this limitation with several key innovations. First, a pupil imaging system scrambles the received light, removing nearly all spatial clutter and permitting a small calibration source to be easily inserted. Then, by using focal plane arrays rather than single detectors to collect the light, dramatic advances in dynamic range can be achieved. Finally, when used with the calibration source, data processing approaches can further mitigate detector non-uniformity effects. DAGR sensors can be made as small as digital cameras and are well suited for downlooking detection of gases in the boundary layer, where solar backscatter measurements are needed to overcome the lack of thermal contrast in the IR. Easily integrated into a satellite platform, a space-based DAGR would provide near-global sensing of climatically important species such as such as CO, CH4, and N2O. Aircraft and UAV measurements with a DAGR could be used to monitor agricultural and industrial emissions. Ground-based or portable DAGRs could augment early warning systems for chemical weapons or toxic materials. Finally, planetary science applications include detection and mapping of biomarkers such as CH4 in the Martian atmosphere.

  6. Color Calibration for Colorized Vision System with Digital Sensor and LED Array Illuminator

    Directory of Open Access Journals (Sweden)

    Zhenmin Zhu

    2016-01-01

    Full Text Available Color measurement by the colorized vision system is a superior method to achieve the evaluation of color objectively and continuously. However, the accuracy of color measurement is influenced by the spectral responses of digital sensor and the spectral mismatch of illumination. In this paper, two-color vision system illuminated by digital sensor and LED array, respectively, is presented. The Polynomial-Based Regression method is applied to solve the problem of color calibration in the sRGB and CIE  L⁎a⁎b⁎ color spaces. By mapping the tristimulus values from RGB to sRGB color space, color difference between the estimated values and the reference values is less than 3ΔE. Additionally, the mapping matrix ΦRGB→sRGB has proved a better performance in reducing the color difference, and it is introduced subsequently into the colorized vision system proposed for a better color measurement. Necessarily, the printed matter of clothes and the colored ceramic tile are chosen as the application experiment samples of our colorized vision system. As shown in the experimental data, the average color difference of images is less than 6ΔE. It indicates that a better performance of color measurement is obtained via the colorized vision system proposed.

  7. Trace gas detection and monitoring with the Digital Array Gas-correlation Radiometer (DAGR)

    Science.gov (United States)

    Gordley, Larry L.; Hervig, Mark E.; Fish, Chad; McHugh, Martin J.

    2011-05-01

    We present the first results from a Digital Array Gas-correlation Radiometer (DAGR) prototype sensor, and discuss applications in remote sensing of trace gases. The sensor concept is based on traditional and reliable Gas Filter Correlation Radiometry (GFCR), but overcomes the limitations in solar backscatter applications. The DAGR sensor design can be scaled to the size of a digital camera and is ideal for downlooking detection of gases in the boundary layer, where solar backscatter measurements are needed to overcome the lack of thermal contrast in the IR. Ground-based portable DAGR sensors can monitor carbon sequestration sites or industrial facilities. Aircraft or UAV deployment can quickly survey large areas and are particularly well suited for gas leak detection or carbon monitoring. From space-based platforms, Doppler modulation can be exploited to produce an extremely fine spectral resolution with effective resolving power exceeding 100,000. Such space-based DAGR observations could provide near-global sensing of climatically important species such as such as CO2, CO, CH4, O3 and N2O. Planetary science applications include detection and mapping of biomarkers in the Martian atmosphere.

  8. Resolution enhancement using pulse width modulation in digital micromirror device-based point-array scanning pattern exposure

    Science.gov (United States)

    Kuo, Hung-Fei; Huang, Yi-Jun

    2016-04-01

    Digital-mask lithography systems, with a digital micromirror device (DMD) as their central piece, have been widely used for defining patterns on printed circuit board (PCB). This study designed optical module parameters for point-array projection lithography based on field tracing technique to improve the quality of the aerial image on the exposure plane. In the realized optical module for the point-array projection lithography, a DMD was used as the dynamic digital-mask, and a 405-nm-wavelength laser was used to illuminate the DMD. The laser was then focused through the micro-lens array in the optical module to form a point array and was projected onto a dynamic scanning stage. By calculating the beam-overlapping rate, stage velocity, spot diameter, and DMD frame rate and programming them into the stage- and DMD-synchronized controller, the point array formed line patterns on the photoresist. Furthermore, using pulse width modulation (PWM) technique to operate the activation periods of the DMD mirrors effectively controlled the exposure and achieved a feature linewidth of less than 10 μm.

  9. A high speed digital data acquisition system for the Indian National Gamma Array at Tata Institute of Fundamental Research

    Energy Technology Data Exchange (ETDEWEB)

    Palit, R., E-mail: palit@tifr.res.in [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Saha, S.; Sethi, J.; Trivedi, T.; Sharma, S.; Naidu, B.S.; Jadhav, S.; Donthi, R.; Chavan, P.B. [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Tan, H.; Hennig, W. [XIA LLC, Hayward, CA 94544 (United States)

    2012-07-11

    A digital data acquisition system for the Compton suppressed clover detector array has been implemented at the TIFR-BARC accelerator facility for the high resolution gamma ray spectroscopy using the Pixie-16 Digital Gamma Finder modules by XIA LLC. This system has a provision for simultaneous digitization of 96 preamplifier signals of high purity germanium crystals. The energy and timing characteristics of the clover detectors have been investigated in detail. In-beam data has been collected both in singles and in the coincidence mode. The system has been tested with 64 channels with each of the 64 crystals having an event rate up to 5 kHz and 2-fold clover coincidence rate up to 15 kHz. The use of the digital data acquisition system has improved the high counting rate handling capabilities for the clover array. Conventional systems with analog shaping are being replaced by digital system that provides higher throughput, better energy resolution and better stability for the multi-detector Compton suppressed clover array.

  10. High throughput optoelectronic smart pixel systems using diffractive optics

    Science.gov (United States)

    Chen, Chih-Hao

    1999-12-01

    Recent developments in digital video, multimedia technology and data networks have greatly increased the demand for high bandwidth communication channels and high throughput data processing. Electronics is particularly suited for switching, amplification and logic functions, while optics is more suitable for interconnections and communications with lower energy and crosstalk. In this research, we present the design, testing, integration and demonstration of several optoelectronic smart pixel devices and system architectures. These systems integrate electronic switching/processing capability with parallel optical interconnections to provide high throughput network communication and pipeline data processing. The Smart Pixel Array Cellular Logic processor (SPARCL) is designed in 0.8 m m CMOS and hybrid integrated with Multiple-Quantum-Well (MQW) devices for pipeline image processing. The Smart Pixel Network Interface (SAPIENT) is designed in 0.6 m m GaAs and monolithically integrated with LEDs to implement a highly parallel optical interconnection network. The Translucent Smart Pixel Array (TRANSPAR) design is implemented in two different versions. The first version, TRANSPAR-MQW, is designed in 0.5 m m CMOS and flip-chip integrated with MQW devices to provide 2-D pipeline processing and translucent networking using the Carrier- Sense-MultipleAccess/Collision-Detection (CSMA/CD) protocol. The other version, TRANSPAR-VM, is designed in 1.2 m m CMOS and discretely integrated with VCSEL-MSM (Vertical-Cavity-Surface- Emitting-Laser and Metal-Semiconductor-Metal detectors) chips and driver/receiver chips on a printed circuit board. The TRANSPAR-VM provides an option of using the token ring network protocol in addition to the embedded functions of TRANSPAR-MQW. These optoelectronic smart pixel systems also require micro-optics devices to provide high resolution, high quality optical interconnections and external source arrays. In this research, we describe an innovative

  11. High Dynamic Range X-ray Detector Pixel Architectures Utilizing Charge Removal

    CERN Document Server

    Weiss, Joel T; Philipp, Hugh T; Becker, Julian; Chamberlain, Darol; Purohit, Prafull; Tate, Mark W; Gruner, Sol M

    2016-01-01

    Several charge integrating CMOS pixel front-ends utilizing charge removal techniques have been fabricated to extend dynamic range for x-ray diffraction applications at synchrotron sources and x-ray free electron lasers (XFELs). The pixels described herein build on the Mixed Mode Pixel Array Detector (MM-PAD) framework, developed previously by our group to perform high dynamic range imaging. These new pixels boast several orders of magnitude improvement in maximum flux over the MM-PAD, which is capable of measuring a sustained flux in excess of 10$^{8}$ x-rays/pixel/second while maintaining sensitivity to smaller signals, down to single x-rays. To extend dynamic range, charge is removed from the integration node of the front-end amplifier without interrupting integration. The number of times this process occurs is recorded by a digital counter in the pixel. The parameter limiting full well is thereby shifted from the size of an integration capacitor to the depth of a digital counter. The result is similar to t...

  12. FE-I4, the new ATLAS pixel chip for upgraded LHC luminosities

    Energy Technology Data Exchange (ETDEWEB)

    Arutinov, David; Barbero, Marlon; Gronewald, Markus; Hemperek, Tomasz; Karagounis, Michael; Krueger, Hans; Kruth, Andre; Wermes, Norbert [Physikalisches Institut, Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany)

    2010-07-01

    The new ATLAS pixel chip FE-I4 is being developed for use in upgraded luminosity environments, in the framework of the Insertable B-Layer (IBL) project and the outer pixel layers of Super-LHC. FE-I4 is designed in a 130 nm CMOS technology and is based on an array of 80 x 336 pixels, each 50 x x250 {mu}m2 and consisting of analog and digital sections. The analog pixel section is designed for low power consumption. The digital architecture is based on a 4 pixel unit called region, which allows for a power-efficient, low recording inefficiency design, and provides a handle to the problem of timewalk. The chip periphery contains a digital control block, a command decoder, powering blocks, a data reformatting unit, an 8b10b coder and a clock multiplier unit, which handles data transmission up to 160 Mb/s for the IBL. Increased power consumption in the inner layers of ATLAS translates into more material for cooling and power routing, which degrades the tracking and the b-tagging quality. As a consequence the FE-I4 collaboration places severe constraints on the power consumption of all blocks. First full scale FE-I4 submission will occur beginning 2010.

  13. High-contrast X-ray micro-tomography of low attenuation samples using large area hybrid semiconductor pixel detector array of 10 × 5 Timepix chips

    Science.gov (United States)

    Karch, J.; Krejci, F.; Bartl, B.; Dudak, J.; Kuba, J.; Kvacek, J.; Zemlicka, J.

    2016-01-01

    State-of-the-art hybrid pixel semiconductor detectors provide excellent imaging properties such as unlimited dynamic range, high spatial resolution, high frame rate and energy sensitivity. Nevertheless, a limitation in the use of these devices for imaging has been the small sensitive area of a few square centimetres. In the field of microtomography we make use of a large area pixel detector assembled from 50 Timepix edgeless chips providing fully sensitive area of 14.3 × 7.15 cm2. We have successfully demonstrated that the enlargement of the sensitive area enables high-quality tomographic measurements of whole objects with high geometrical magnification without any significant degradation in resulting reconstructions related to the chip tilling and edgeless sensor technology properties. The technique of micro-tomography with the newly developed large area detector is applied for samples formed by low attenuation, low contrast materials such a seed from Phacelia tanacetifolia, a charcoalified wood sample and a beeswax seal sample.

  14. Development of SOI pixel detector in Cracow

    CERN Document Server

    Bugiel, Szymon; Glab, Sebastian; Idzik, Marek; Moron, Jakub; Kapusta, Piotr Julian; Kucewicz, Wojciech; Turala, Michal

    2015-01-01

    This paper presents the design of a new monolithic Silicon-On-Insulator pixel sensor in $200~nm$ SOI CMOS technology. The main application of the proposed pixel detector is the spectroscopy, but it can also be used for the minimum ionizing particle (MIP) tracking in particle physics experiments. For this reason few different versions of pixel cells are developed: a source-follower based pixel for tracking, a low noise pixel with preamplifier for spectroscopy, and a self-triggering pixel for time and amplitude measurements. In addition the design of a Successive Approximation Register Analog-to-Digital Converter (SAR ADC) is also presented. A 10-bit SAR ADC is developed for spectroscopic measurements and a lower resolution 6-bit SAR ADC is integrated in the pixel matrix as a column ADC, for tracking applications.

  15. Adopt a Pixel Photographs: 2013-Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The photographs in the Adopt a Pixel collection were provided by volunteers with a digital camera, a Global Positioning System (GPS), and a compass or a smart mobile...

  16. Adopt a Pixel Photographs: 2013-Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The photographs in the Adopt a Pixel collection were provided by volunteers with a digital camera, a Global Positioning System (GPS), and a compass or a smart mobile...

  17. Adopt a Pixel Photographs: 2013-Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The photographs in the Adopt a Pixel collection were provided by volunteers with a digital camera, a Global Positioning System (GPS), and a compass or a smart...

  18. Development and performance evaluation of Time-over-Threshold based digital PET (TODPET2) scanner using SiPM/Ce:GAGG-arrays for non-invasive measurement of blood RI concentrations

    Science.gov (United States)

    Yoshino, M.; Kamada, K.; Shoji, Y.; Yoshikawa, A.; Shimazoe, K.; Lipovec, A.; Takahashi, H.; Fujiwara, K.; Takahashi, M.; Momose, T.; Ito, S.; Tsutsumi, K.; Endo, T.; Sato, H.; Usuki, Y.

    2017-02-01

    We developed Time-over-Threshold based digital PET (TODPET2) tomograph using silicon photomultipliers (SiPM) arrays coupled with pixelized Ce:Gd3(Ga, Al)5O12 (Ce:GAGG) scintillators dedicated for non-invasive measurement of blood RI concentrations. The detector consists of 1.57 × 1.57 mm2 SiPM chips and 1.6 × 1.6 × 15 mm3 Ce:GAGG scintillators arranged on a 12 × 12 channel, both working as individual readout systems. After the development of the detector, we fabricated the PET gantry composed of 8 pieces of SiPM/Ce:GAGG detector array which signals were sent to the current-comparing type time-over-threshold (TOT) ASIC for individual readout of pixels. The PET scanner which we developed has 25 mm axial field-of-view (FOV) and 60 mm transaxial FOV. The spatial resolution reconstructed with maximum likelihood estimation method (MLEM) is 0.98 mm (FWHM) at the center of FOV. The sensitivity of the system is measured to be 1.31% using 22Na point source. Finally, timing response to changes in RI concentration was also measured using 5 mm diameter syringe injected with several concentrations of 18FDG.

  19. Picoliter Well Array Chip-Based Digital Recombinase Polymerase Amplification for Absolute Quantification of Nucleic Acids.

    Science.gov (United States)

    Li, Zhao; Liu, Yong; Wei, Qingquan; Liu, Yuanjie; Liu, Wenwen; Zhang, Xuelian; Yu, Yude

    2016-01-01

    Absolute, precise quantification methods expand the scope of nucleic acids research and have many practical applications. Digital polymerase chain reaction (dPCR) is a powerful method for nucleic acid detection and absolute quantification. However, it requires thermal cycling and accurate temperature control, which are difficult in resource-limited conditions. Accordingly, isothermal methods, such as recombinase polymerase amplification (RPA), are more attractive. We developed a picoliter well array (PWA) chip with 27,000 consistently sized picoliter reactions (314 pL) for isothermal DNA quantification using digital RPA (dRPA) at 39°C. Sample loading using a scraping liquid blade was simple, fast, and required small reagent volumes (i.e., PEG-silane agent effectively eliminated cross-contamination during dRPA. Our creative optical design enabled wide-field fluorescence imaging in situ and both end-point and real-time analyses of picoliter wells in a 6-cm(2) area. It was not necessary to use scan shooting and stitch serial small images together. Using this method, we quantified serial dilutions of a Listeria monocytogenes gDNA stock solution from 9 × 10(-1) to 4 × 10(-3) copies per well with an average error of less than 11% (N = 15). Overall dRPA-on-chip processing required less than 30 min, which was a 4-fold decrease compared to dPCR, requiring approximately 2 h. dRPA on the PWA chip provides a simple and highly sensitive method to quantify nucleic acids without thermal cycling or precise micropump/microvalve control. It has applications in fast field analysis and critical clinical diagnostics under resource-limited settings.

  20. Picoliter Well Array Chip-Based Digital Recombinase Polymerase Amplification for Absolute Quantification of Nucleic Acids

    Science.gov (United States)

    Li, Zhao; Liu, Yong; Wei, Qingquan; Liu, Yuanjie; Liu, Wenwen; Zhang, Xuelian; Yu, Yude

    2016-01-01

    Absolute, precise quantification methods expand the scope of nucleic acids research and have many practical applications. Digital polymerase chain reaction (dPCR) is a powerful method for nucleic acid detection and absolute quantification. However, it requires thermal cycling and accurate temperature control, which are difficult in resource-limited conditions. Accordingly, isothermal methods, such as recombinase polymerase amplification (RPA), are more attractive. We developed a picoliter well array (PWA) chip with 27,000 consistently sized picoliter reactions (314 pL) for isothermal DNA quantification using digital RPA (dRPA) at 39°C. Sample loading using a scraping liquid blade was simple, fast, and required small reagent volumes (i.e., <20 μL). Passivating the chip surface using a methoxy-PEG-silane agent effectively eliminated cross-contamination during dRPA. Our creative optical design enabled wide-field fluorescence imaging in situ and both end-point and real-time analyses of picoliter wells in a 6-cm2 area. It was not necessary to use scan shooting and stitch serial small images together. Using this method, we quantified serial dilutions of a Listeria monocytogenes gDNA stock solution from 9 × 10-1 to 4 × 10-3 copies per well with an average error of less than 11% (N = 15). Overall dRPA-on-chip processing required less than 30 min, which was a 4-fold decrease compared to dPCR, requiring approximately 2 h. dRPA on the PWA chip provides a simple and highly sensitive method to quantify nucleic acids without thermal cycling or precise micropump/microvalve control. It has applications in fast field analysis and critical clinical diagnostics under resource-limited settings. PMID:27074005

  1. Ultrahigh Detective Heterogeneous Photosensor Arrays with In-Pixel Signal Boosting Capability for Large-Area and Skin-Compatible Electronics.

    Science.gov (United States)

    Kim, Jaehyun; Kim, Jaekyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Myungwon; Moon, Juhyuk; Yang, Lin; Kim, Myung-Gil; Kim, Yong-Hoon; Park, Sung Kyu

    2016-04-01

    An ultra-thin and large-area skin-compatible heterogeneous organic/metal-oxide photosensor array is demonstrated which is capable of sensing and boosting signals with high detectivity and signal-to-noise ratio. For the realization of ultra-flexible and high-sensitive heterogeneous photosensor arrays on a polyimide substrate having organic sensor arrays and metal-oxide boosting circuitry, solution-processing and room-temperature alternating photochemical conversion routes are applied. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Investigation of certain characteristics of thinned antenna arrays with digital signal processing

    Science.gov (United States)

    Danilevskii, L. V.; Domanov, Iu. A.; Korobko, O. V.; Tauroginskii, B. I.

    1983-11-01

    A thinned array with correlation processing of input signals is examined. It is shown that amplitude quantization does not change the signal at the thinned-array input as compared with the complete antenna array. The discreteness of time delay causes the thinned and complete arrays to become nonequivalent. Computer-simulation results are presented.

  3. Standard practice for digital detector array performance evaluation and long-term stability

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice describes the evaluation of DDA systems for industrial radiology. It is intended to ensure that the evaluation of image quality, as far as this is influenced by the DDA system, meets the needs of users, and their customers, and enables process control and long term stability of the DDA system. 1.2 This practice specifies the fundamental parameters of Digital Detector Array (DDA) systems to be measured to determine baseline performance, and to track the long term stability of the DDA system. 1.3 The DDA system performance tests specified in this practice shall be completed upon acceptance of the system from the manufacturer and at intervals specified in this practice to monitor long term stability of the system. The intent of these tests is to monitor the system performance for degradation and to identify when an action needs to be taken when the system degrades by a certain level. 1.4 The use of the gages provided in this standard is mandatory for each test. In the event these tests or ga...

  4. Design of equivalent pixel circuit for infrared focal plane array%用于红外焦平面阵列的等效像元电路设计

    Institute of Scientific and Technical Information of China (English)

    戴山彪; 陈力颖; 邢海英; 王健; 杨晓龙

    2015-01-01

    An equivalent pixel circuit for 300 ×400 infrared focal plane array readout circuit structure is presented in this paper.The circuit′s electrical characteristics are equivalent to that of the vanadium oxide (VOx film)micro -mechanical systems (MEMS).It can simulate the variation of the branch current when the MEMS pixel changes.Be-fore the growth of physical structure of MEMS (VOx film),the infrared array detector readout circuit has been fabrica-ted.The equivalent pixel circuit is designed to test the electrical properties of the readout circuit.It can remove the defective products and reduce packaging costs.The circuit has been designed and fabricated with a GlobalFoundry 0.35 μm process.The test results indicate that the equivalent circuit has the same electrical properties as the MEMS pixel when the integrating current is 0 ~200 nA.%提出了一种用于300×400红外焦平面阵列读出电路的等效像元电路结构。该电路与氧化钒(VOx 薄膜)制成的微机械系统(MEMS)的电特性等效,并能够模拟 MEMS 像元改变时支路电流的变化。红外面阵探测器读出电路在流片后,生长 MEMS 物理结构(VOx 薄膜)前,该等效像元电路结构用于读出电路的电性能测试,从而剔除不良品,减少封装成本。该电路采用了 GlobalFoundry 0.35μm 工艺设计并流片。测试结果表明,当积分电流为0~200 nA 时,该等效像元电路的电性能与 MEMS 像元一致。

  5. Developments of FPGA-based digital back-ends for low frequency antenna arrays at Medicina radio telescopes

    Science.gov (United States)

    Naldi, G.; Bartolini, M.; Mattana, A.; Pupillo, G.; Hickish, J.; Foster, G.; Bianchi, G.; Lingua, A.; Monari, J.; Montebugnoli, S.; Perini, F.; Rusticelli, S.; Schiaffino, M.; Virone, G.; Zarb Adami, K.

    In radio astronomy Field Programmable Gate Array (FPGA) technology is largely used for the implementation of digital signal processing techniques applied to antenna arrays. This is mainly due to the good trade-off among computing resources, power consumption and cost offered by FPGA chip compared to other technologies like ASIC, GPU and CPU. In the last years several digital backend systems based on such devices have been developed at the Medicina radio astronomical station (INAF-IRA, Bologna, Italy). Instruments like FX correlator, direct imager, beamformer, multi-beam system have been successfully designed and realized on CASPER (Collaboration for Astronomy Signal Processing and Electronics Research, https://casper.berkeley.edu) processing boards. In this paper we present the gained experience in this kind of applications.

  6. The Digital Signal Processing Platform for the Low Frequency Aperture Array: Preliminary Results on the Data Acquisition Unit

    Science.gov (United States)

    Naldi, Giovanni; Mattana, Andrea; Pastore, Sandro; Alderighi, Monica; Zarb Adami, Kristian; Schillirò, Francesco; Aminaei, Amin; Baker, Jeremy; Belli, Carolina; Comoretto, Gianni; Chiarucci, Simone; Chiello, Riccardo; D'Angelo, Sergio; Dalle Mura, Gabriele; De Marco, Andrea; Halsall, Rob; Magro, Alessio; Monari, Jader; Roberts, Matt; Perini, Federico; Poloni, Marco; Pupillo, Giuseppe; Rusticelli, Simone; Schiaffino, Marco; Zaccaro, Emanuele

    A signal processing hardware platform has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA). The processing board, called an Analog Digital Unit (ADU), is able to acquire and digitize broadband (up to 500MHz bandwidth) radio-frequency streams from 16 dual polarized antennas, channel the data streams and then combine them flexibly as part of a larger beamforming system. It is envisaged that there will be more than 8000 of these signal processing platforms in the first phase of the SKA, so particular attention has been devoted to ensure the design is low-cost and low-power. This paper describes the main features of the data acquisition unit of such a platform and presents preliminary results characterizing its performance.

  7. It's not the pixel count, you fool

    Science.gov (United States)

    Kriss, Michael A.

    2012-01-01

    The first thing a "marketing guy" asks the digital camera engineer is "how many pixels does it have, for we need as many mega pixels as possible since the other guys are killing us with their "umpteen" mega pixel pocket sized digital cameras. And so it goes until the pixels get smaller and smaller in order to inflate the pixel count in the never-ending pixel-wars. These small pixels just are not very good. The truth of the matter is that the most important feature of digital cameras in the last five years is the automatic motion control to stabilize the image on the sensor along with some very sophisticated image processing. All the rest has been hype and some "cool" design. What is the future for digital imaging and what will drive growth of camera sales (not counting the cell phone cameras which totally dominate the market in terms of camera sales) and more importantly after sales profits? Well sit in on the Dark Side of Color and find out what is being done to increase the after sales profits and don't be surprised if has been done long ago in some basement lab of a photographic company and of course, before its time.

  8. A digital instantaneous frequency measurement technique utilising high speed analogue to digital converters and field programmable gate arrays

    CSIR Research Space (South Africa)

    Herselman, PLR

    2007-09-01

    Full Text Available In modern information and sensor systems, the timely estimation of the carrier frequency of received signals is of critical importance. This paper presents a digital instantaneous frequency measurement (DIFM) technique, which can measure the carrier...

  9. Penrose Pixels for Super-Resolution.

    Science.gov (United States)

    Ben-Ezra, M; Lin, Zhouchen; Wilburn, Bennett; Zhang, Wei

    2011-07-01

    We present a novel approach to reconstruction-based super-resolution that uses aperiodic pixel tilings, such as a Penrose tiling or a biological retina, for improved performance. To this aim, we develop a new variant of the well-known error back projection super-resolution algorithm that makes use of the exact detector model in its back projection operator for better accuracy. Pixels in our model can vary in shape and size, and there may be gaps between adjacent pixels. The algorithm applies equally well to periodic or aperiodic pixel tilings. We present analysis and extensive tests using synthetic and real images to show that our approach using aperiodic layouts substantially outperforms existing reconstruction-based algorithms for regular pixel arrays. We close with a discussion of the feasibility of manufacturing CMOS or CCD chips with pixels arranged in Penrose tilings.

  10. Fast, High-Precision Readout Circuit for Detector Arrays

    Science.gov (United States)

    Rider, David M.; Hancock, Bruce R.; Key, Richard W.; Cunningham, Thomas J.; Wrigley, Chris J.; Seshadri, Suresh; Sander, Stanley P.; Blavier, Jean-Francois L.

    2013-01-01

    The GEO-CAPE mission described in NASA's Earth Science and Applications Decadal Survey requires high spatial, temporal, and spectral resolution measurements to monitor and characterize the rapidly changing chemistry of the troposphere over North and South Americas. High-frame-rate focal plane arrays (FPAs) with many pixels are needed to enable such measurements. A high-throughput digital detector readout integrated circuit (ROIC) that meets the GEO-CAPE FPA needs has been developed, fabricated, and tested. The ROIC is based on an innovative charge integrating, fast, high-precision analog-to-digital circuit that is built into each pixel. The 128×128-pixel ROIC digitizes all 16,384 pixels simultaneously at frame rates up to 16 kHz to provide a completely digital output on a single integrated circuit at an unprecedented rate of 262 million pixels per second. The approach eliminates the need for off focal plane electronics, greatly reducing volume, mass, and power compared to conventional FPA implementations. A focal plane based on this ROIC will require less than 2 W of power on a 1×1-cm integrated circuit. The ROIC is fabricated of silicon using CMOS technology. It is designed to be indium bump bonded to a variety of detector materials including silicon PIN diodes, indium antimonide (InSb), indium gallium arsenide (In- GaAs), and mercury cadmium telluride (HgCdTe) detector arrays to provide coverage over a broad spectral range in the infrared, visible, and ultraviolet spectral ranges.

  11. All-Digital Wideband Space-Frequency Beamforming for the SKA Aperture Array

    CERN Document Server

    Khlebnikov, Vasily A; Armstrong, Richard P; Jones, Michael E

    2010-01-01

    In this paper, we consider the problem of optimum multi-domain real-time beamforming and high-precision beam pattern positioning in application to very large wideband array antennas, particularly to the Square Kilometre Array (SKA) aperture array antenna. We present a new structure for wideband space-frequency beamforming and beamsteering that maximizes detectability of cosmic signals over the array operational frequency range.

  12. A new generation of small pixel pitch/SWaP cooled infrared detectors

    Science.gov (United States)

    Espuno, L.; Pacaud, O.; Reibel, Y.; Rubaldo, L.; Kerlain, A.; Péré-Laperne, N.; Dariel, A.; Roumegoux, J.; Brunner, A.; Kessler, A.; Gravrand, O.; Castelein, P.

    2015-10-01

    Following clear technological trends, the cooled IR detectors market is now in demand for smaller, more efficient and higher performance products. This demand pushes products developments towards constant innovations on detectors, read-out circuits, proximity electronics boards, and coolers. Sofradir was first to show a 10μm focal plane array (FPA) at DSS 2012, and announced the DAPHNIS 10μm product line back in 2014. This pixel pitch is a key enabler for infrared detectors with increased resolution. Sofradir recently achieved outstanding products demonstrations at this pixel pitch, which clearly demonstrate the benefits of adopting 10μm pixel pitch focal plane array-based detectors. Both HD and XGA Daphnis 10μm products also benefit from a global video datapath efficiency improvement by transitioning to digital video interfaces. Moreover, innovative smart pixels functionalities drastically increase product versatility. In addition to this strong push towards a higher pixels density, Sofradir acknowledges the need for smaller and lower power cooled infrared detector. Together with straightforward system interfaces and better overall performances, latest technological advances on SWAP-C (Size, Weight, Power and Cost) Sofradir products enable the advent of a new generation of high performance portable and agile systems (handheld thermal imagers, unmanned aerial vehicles, light gimbals etc...). This paper focuses on those features and performances that can make an actual difference in the field.

  13. A Low-Noise CMOS Pixel Direct Charge Sensor, Topmetal-II-

    CERN Document Server

    An, Mangmang; Gao, Chaosong; Han, Mikyung; Ji, Rong; Li, Xiaoting; Mei, Yuan; Sun, Quan; Sun, Xiangming; Wang, Kai; Xiao, Le; Xu, Nu; Yang, Ping; Zhou, Wei

    2016-01-01

    We report the design and characterization of a CMOS pixel direct charge sensor, Topmetal-II-, fabricated in a standard 0.35um CMOS Integrated Circuit process. The sensor utilizes exposed metal patches on top of each pixel to directly collect charge. Each pixel contains a low-noise charge-sensitive preamplifier to establish the analog signal and a discriminator with tunable threshold to generate hits. The analog signal from each pixel is accessible through time-shared multiplexing over the entire array. Hits are read out digitally through a column-based priority logic structure. Tests show that the sensor achieved a <15e- analog noise and a 200e- minimum threshold for digital readout per pixel. The sensor is capable of detecting both electrons and ions drifting in gas. These characteristics enable its use as the charge readout device in future Time Projection Chambers without gaseous gain mechanism, which has unique advantages in low background and low rate-density experiments.

  14. A low-noise CMOS pixel direct charge sensor, Topmetal-II-

    Science.gov (United States)

    An, Mangmang; Chen, Chufeng; Gao, Chaosong; Han, Mikyung; Ji, Rong; Li, Xiaoting; Mei, Yuan; Sun, Quan; Sun, Xiangming; Wang, Kai; Xiao, Le; Yang, Ping; Zhou, Wei

    2016-02-01

    We report the design and characterization of a CMOS pixel direct charge sensor, Topmetal-II-, fabricated in a standard 0.35 μm CMOS Integrated Circuit process. The sensor utilizes exposed metal patches on top of each pixel to directly collect charge. Each pixel contains a low-noise charge-sensitive preamplifier to establish the analog signal and a discriminator with tunable threshold to generate hits. The analog signal from each pixel is accessible through time-shared multiplexing over the entire array. Hits are read out digitally through a column-based priority logic structure. Tests show that the sensor achieved a analog noise and a 200e- minimum threshold for digital readout per pixel. The sensor is capable of detecting both electrons and ions drifting in gas. These characteristics enable its use as the charge readout device in future Time Projection Chambers without gaseous gain mechanism, which has unique advantages in low background and low rate-density experiments.

  15. FE-I4, the New ATLAS Pixel Chip for Upgraded LHC Luminosities

    CERN Document Server

    "Barbero, M; The ATLAS collaboration

    2009-01-01

    The new ATLAS pixel chip FE-I4 is being developed for use in upgraded luminosity environments, in the framework of the Insertable B-Layer (IBL) project but also for the outer pixel layers of Super-LHC. FE-I4 is designed in a 130 nm technology and is based on an array of 80 by 336 pixels, each 50×250 μm2 and consisting of analog and digital sections. The analog pixel section is designed for low power consumption and compatibility to several sensor candidates. The digital architecture is based on a 4 pixel unit called region, which allows for a power-efficient, low recording inefficiency design, and provides an elegant solution to the problem of timewalk. The chip periphery contains a control block, powering blocks, a data reformatting unit, an asynchronous storage FIFO, an 8b10b coder and a clock multiplier unit, which handles data transmission up to 160 Mb/s for the IBL.

  16. Low-noise low-jitter 32-pixels CMOS single-photon avalanche diodes array for single-photon counting from 300 nm to 900 nm

    Energy Technology Data Exchange (ETDEWEB)

    Scarcella, Carmelo; Tosi, Alberto, E-mail: alberto.tosi@polimi.it; Villa, Federica; Tisa, Simone; Zappa, Franco [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy)

    2013-12-15

    We developed a single-photon counting multichannel detection system, based on a monolithic linear array of 32 CMOS SPADs (Complementary Metal-Oxide-Semiconductor Single-Photon Avalanche Diodes). All channels achieve a timing resolution of 100 ps (full-width at half maximum) and a photon detection efficiency of 50% at 400 nm. Dark count rate is very low even at room temperature, being about 125 counts/s for 50 μm active area diameter SPADs. Detection performance and microelectronic compactness of this CMOS SPAD array make it the best candidate for ultra-compact time-resolved spectrometers with single-photon sensitivity from 300 nm to 900 nm.

  17. Multidimensional Systolic Arrays of LMS AlgorithmAdaptive (FIR Digital Filters

    Directory of Open Access Journals (Sweden)

    Bakir A. R. Al-Hashemy

    2009-01-01

    Full Text Available A multidimensional systolic arrays realization of LMS algorithm by a method of mapping regular algorithm onto processor array, are designed. They are based on appropriately selected 1-D systolic array filter that depends on the inner product sum systolic implementation. Various arrays may be derived that exhibit a regular arrangement of the cells (processors and local interconnection pattern, which are important for VLSI implementation. It reduces latency time and increases the throughput rate in comparison to classical 1-D systolic arrays. The 3-D multilayered array consists of 2-D layers, which are connected with each other only by edges. Such arrays for LMS-based adaptive (FIR filter may be opposed the fundamental requirements of fast convergence rate in most adaptive filter applications.

  18. 3 mega-pixel InSb detector with 10μm pitch

    Science.gov (United States)

    Gershon, G.; Albo, A.; Eylon, M.; Cohen, O.; Calahorra, Z.; Brumer, M.; Nitzani, M.; Avnon, E.; Aghion, Y.; Kogan, I.; Ilan, E.; Shkedy, L.

    2013-06-01

    SCD has developed a new 1920x1536 / 10 μm digital Infrared detector for the MWIR window named Blackbird. The Blackbird detector features a Focal Plane Array (FPA) that incorporates two technological building blocks developed over the past few years. The first one is a 10 μm InSb pixel based on the matured planar technology. The second building block is an innovative 10 μm ReadOut Integrated Circuit (ROIC) pixel. The InSb and the ROIC arrays are connected using Flip-Chip technology by means of indium bumps. The digital ROIC consists a matrix of 1920x1536 pixels and has an analog to digital (A/D) converter per-channel (total of 1920x2 A/Ds). It allows for full frame readout at a high frame rate of up to 120 Hz. Such an on-chip A/D conversion eliminates the need for several A/D converters with fairly high power consumption at the system level. The ROIC power consumption at maximum bandwidth is less than 400 mW. It features a wide range of pixel-level functionality such as several conversion gain options and a 2x2 pixel binning. The ROIC design makes use of the advanced and matured CMOS technology, 0.18 μm, which allows for high functionality and relatively low power consumption. The FPA is mounted on a Cold-Finger by a specially designed ceramic substrate. The whole assembly is housed in a stiffened Dewar that withstands harsh environmental conditions while minimizing the environment heat load contribution to the heat load of the detector. The design enables a 3-megapixel detector with overall low size, weight, and power (SWaP) with respect to comparable large format detectors. In this work we present in detail the characteristic performance of the new Blackbird detector.

  19. Characterization of a mammographic system based on single photon counting pixel arrays coupled to GaAs x-ray detectors.

    Science.gov (United States)

    Amendolia, S R; Bisogni, M G; Delogu, P; Fantacci, M E; Paternoster, G; Rosso, V; Stefanini, A

    2009-04-01

    The authors report on the imaging capabilities of a mammographic system demonstrator based on GaAs pixel detectors operating in single photon counting (SPC) mode. The system imaging performances have been assessed by means of the transfer functions: The modulation transfer function (MTF), the normalized noise power spectrum, and the detective quantum efficiency (DQE) have been measured following the guidelines of the IEC 62220-1-2 protocol. The transfer function analysis has shown the high spatial resolution capabilities of the GaAs detectors. The MTF calculated at the Nyquist frequency (2.94 cycles/mm) is indeed 60%. The DQE, measured with a standard mammographic beam setup (Mo/Mo, 28 kVp, with 4 mm Al added filter) and calculated at zero frequency, is 46%. Aiming to further improve the system's image quality, the authors investigate the DQE limiting factors and show that they are mainly related to system engineering. For example, the authors show that optimization of the image equalization procedure increases the DQE(0) up to 74%, which is better than the DQE(0) of most clinical mammographic systems. The authors show how the high detection efficiency of GaAs detectors and the noise discrimination associated with the SPC technology allow optimizing the image quality in mammography. In conclusion, the authors propose technological solutions to exploit to the utmost the potentiality of GaAs detectors coupled to SPC electronics.

  20. Digital Elevation Model (DEM), Allegany County DEM 10 ft pixel, Published in 2005, 1:1200 (1in=100ft) scale, Allegany County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Digital Elevation Model (DEM) dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from LIDAR information as of 2005. It is described as...

  1. A digital output accelerometer using MEMS-based piezoelectric accelerometers and arrayed CMOS inverters with satellite capacitors

    Science.gov (United States)

    Kobayashi, T.; Okada, H.; Masuda, T.; Maeda, R.; Itoh, T.

    2011-06-01

    The present paper describes the development of a digital output accelerometer composed of microelectromechanical systems (MEMS)-based piezoelectric accelerometers and arrayed complementary metal-oxide-semiconductor (CMOS) inverters accompanied by capacitors. The piezoelectric accelerometers were fabricated from multilayers of Pt/Ti/PZT/Pt/Ti/SiO2 deposited on silicon-on-insulator (SOI) wafers. The fabricated piezoelectric accelerometers were connected to arrayed CMOS inverters. Each of the CMOS inverters was accompanied by a capacitor with a different capacitance called a 'satellite capacitor'. We have confirmed that the output voltage generated from the piezoelectric accelerometers can vary the output of the CMOS inverters from a high to a low level; the state of the CMOS inverters has turned from the 'off-state' into the 'on-state' when the output voltage of the piezoelectric accelerometers is larger than the threshold voltage of the CMOS inverters. We have also confirmed that the CMOS inverters accompanied by the larger satellite capacitor have become 'on-state' at a lower acceleration. On increasing the acceleration, the number of on-state CMOS inverters has increased. Assuming that the on-state and off-state of CMOS inverters correspond to logic '0' and '1', the present digital output accelerometers have expressed the accelerations of 2.0, 3.0, 5.0, and 5.5 m s - 2 as digital outputs of 111, 110, 100, and 000, respectively.

  2. Segmentation and intensity estimation for microarray images with saturated pixels

    Directory of Open Access Journals (Sweden)

    Yang Yan

    2011-11-01

    Full Text Available Abstract Background Microarray image analysis processes scanned digital images of hybridized arrays to produce the input spot-level data for downstream analysis, so it can have a potentially large impact on those and subsequent analysis. Signal saturation is an optical effect that occurs when some pixel values for highly expressed genes or peptides exceed the upper detection threshold of the scanner software (216 - 1 = 65, 535 for 16-bit images. In practice, spots with a sizable number of saturated pixels are often flagged and discarded. Alternatively, the saturated values are used without adjustments for estimating spot intensities. The resulting expression data tend to be biased downwards and can distort high-level analysis that relies on these data. Hence, it is crucial to effectively correct for signal saturation. Results We developed a flexible mixture model-based segmentation and spot intensity estimation procedure that accounts for saturated pixels by incorporating a censored component in the mixture model. As demonstrated with biological data and simulation, our method extends the dynamic range of expression data beyond the saturation threshold and is effective in correcting saturation-induced bias when the lost information is not tremendous. We further illustrate the impact of image processing on downstream classification, showing that the proposed method can increase diagnostic accuracy using data from a lymphoma cancer diagnosis study. Conclusions The presented method adjusts for signal saturation at the segmentation stage that identifies a pixel as part of the foreground, background or other. The cluster membership of a pixel can be altered versus treating saturated values as truly observed. Thus, the resulting spot intensity estimates may be more accurate than those obtained from existing methods that correct for saturation based on already segmented data. As a model-based segmentation method, our procedure is able to identify inner

  3. Implementation of a high resolution (< 11 ps RMS) Time-to-Digital Converter in a Field Programmable Gate Array

    Energy Technology Data Exchange (ETDEWEB)

    Ugur, Cahit [Helmholtz-Institut Mainz, Johannes Gutenberg-Universitaet Mainz (Germany); Bayer, Eugen [Department for Digital Electronics, University Kassel (Germany); Kurz, Nikolaus; Traxler, Michael [GSI Helmholtz Centre for Heavy Ion Research, Darmstadt (Germany); Michel, Jan [Institute for Nuclear Physics, Goethe University Frankfurt, Frankfurt am Main (Germany)

    2012-07-01

    A high resolution time-to-digital converter (TDC) was implemented in a general purpose field-programmable gate array (FPGA), a re-programmable digital chip. RMS and the time resolution of different channels are calculated for one clock cycle (5 ns) interval and a minimum of 10.3 ps RMS on two channels is achieved, which yields to a time resolution of 7.3 ps (10.3 ps/{radical}(2)) on a single channel. The TDC can be used in time-of-flight, time-over-threshold, drift time measurement applications as well as many other measurements with specific Front-End Electronics (FEE), e.g. charge measurements with charge-to-width (Q2W) FEE. The re-programmable flexibility of FPGAs also allows to have application specific features, e.g. trigger window, zero dead time etc.

  4. A Search for Radio Gravitational Lenses, Using the Sloan Digital Sky Survey and the Very Large Array

    CERN Document Server

    Boyce, E R; Bolton, A S; Hewitt, J N; Burles, S; Boyce, Edward R.; Bowman, Judd D.; Bolton, Adam S.; Hewitt, Jacqueline N.; Burles, Scott

    2006-01-01

    We report on a novel search for radio gravitational lenses. Using the Very Large Array, we imaged ten candidates with both dual redshifts in Sloan Digital Sky Survey spectra and 1.4 GHz radio flux >2 mJy in the FIRST survey. The VLA maps show that in each case the radio emission is associated with the foreground galaxy rather than being lensed emission from the background galaxy, although at least four of our targets are strong lenses at optical wavelengths. These SDSS dual-redshift systems do not have lensed radio emission at the sensitivity of current radio surveys.

  5. Effect of Pixel’s Spatial Characteristics on Recognition of Isolated Pixelized Chinese Character

    Science.gov (United States)

    Yang, Kun; Liu, Shuang; Wang, Hong; Liu, Wei; Wu, Yaowei

    2015-01-01

    The influence of pixel’s spatial characteristics on recognition of isolated Chinese character was investigated using simulated prosthestic vision. The accuracy of Chinese character recognition with 4 kinds of pixel number (6*6, 8*8, 10*10, and 12*12 pixel array) and 3 kinds of pixel shape (Square, Dot and Gaussian) and different pixel spacing were tested through head-mounted display (HMD). A captured image of Chinese characters in font style of Hei were pixelized with Square, Dot and Gaussian pixel. Results showed that pixel number was the most important factor which could affect the recognition of isolated pixelized Chinese Chartars and the accuracy of recognition increased with the addition of pixel number. 10*10 pixel array could provide enough information for people to recognize an isolated Chinese character. At low resolution (6*6 and 8*8 pixel array), there were little difference of recognition accuracy between different pixel shape and different pixel spacing. While as for high resolution (10*10 and 12*12 pixel array), the fluctuation of pixel shape and pixel spacing could not affect the performance of recognition of isolated pixelized Chinese Character. PMID:26628934

  6. Frequency division multiplexed microwave and baseband digital optical fiber link for phased array antennas

    Science.gov (United States)

    Heim, Peter J.; McClay, C. Phillip

    1990-05-01

    A frequency-division multiplexed optical fiber link is described in which microwave (1-8 GHz) and baseband digital (1-10 Mb/s) signals are combined electrically and transmitted through a direct-modulation microwave optical link. The microwave signal does not affect bit error rate (BER) performance of the Manchester-coded baseband digital data link. The baseband digital signal affects microwave signal quality by generating second-order intermodulation noise. The intermodulation noise power density is found to be proportional to both the microwave input power and the digital input power, enabling the system to be modeled as a mixer (AM modulator). The conversion loss for the digital signal is approximately 68 dB for a 1-GHz microwave signal and is highly dependent on the microwave frequency, reaching a minimum value of 41 dB at 4.5 GHz, corresponding to the laser diode relaxation oscillation frequency. It is shown that Manchester coding on the digital link places the intermodulation noise peak away from the microwave signal, preventing degradation of close-carrier phase noise (<1 kHz offset). A direct trade-off between intermodulation noise and digital link margin is developed to project system performance.

  7. Low-power Broadband Digitizer for Millimeter-Wave Sensor Array Readout Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Multiplexing in frequency domain using a bank of high-Q micro-resonators is an emerging method of reading out large arrays of transition-edge sensors and...

  8. A neighbor pixel communication filtering structure for Dynamic Vision Sensors

    Science.gov (United States)

    Xu, Yuan; Liu, Shiqi; Lu, Hehui; Zhang, Zilong

    2017-02-01

    For Dynamic Vision Sensors (DVS), thermal noise and junction leakage current induced Background Activity (BA) is the major cause of the deterioration of images quality. Inspired by the smoothing filtering principle of horizontal cells in vertebrate retina, A DVS pixel with Neighbor Pixel Communication (NPC) filtering structure is proposed to solve this issue. The NPC structure is designed to judge the validity of pixel's activity through the communication between its 4 adjacent pixels. The pixel's outputs will be suppressed if its activities are determined not real. The proposed pixel's area is 23.76×24.71μm2 and only 3ns output latency is introduced. In order to validate the effectiveness of the structure, a 5×5 pixel array has been implemented in SMIC 0.13μm CIS process. 3 test cases of array's behavioral model show that the NPC-DVS have an ability of filtering the BA.

  9. GOSSIPO-4: an array of high resolution TDCs with a PLL control

    NARCIS (Netherlands)

    Zappon, F.; van Beuzekom, M.; Gromov, V.; Kluit, R.; Fang, X.; Kruth, A.

    2012-01-01

    GOSSIPO-4 is a prototype chip featuring an array of high resolution Time to Digital Converters with a PLL control that has been taped out the 9th of August 2011. This prototype is the successor of GOSSIPO-3 test chip and the precursor of the 65k pixel chip TimePix3. The prototype is being developed

  10. An experimental study of the scatter correction by using a beam-stop-array algorithm with digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ye-Seul; Park, Hye-Suk; Kim, Hee-Joung [Yonsei University, Wonju (Korea, Republic of); Choi, Young-Wook; Choi, Jae-Gu [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of)

    2014-12-15

    Digital breast tomosynthesis (DBT) is a technique that was developed to overcome the limitations of conventional digital mammography by reconstructing slices through the breast from projections acquired at different angles. In developing and optimizing DBT, The x-ray scatter reduction technique remains a significant challenge due to projection geometry and radiation dose limitations. The most common approach to scatter reduction is a beam-stop-array (BSA) algorithm; however, this method raises concerns regarding the additional exposure involved in acquiring the scatter distribution. The compressed breast is roughly symmetric, and the scatter profiles from projections acquired at axially opposite angles are similar to mirror images. The purpose of this study was to apply the BSA algorithm with only two scans with a beam stop array, which estimates the scatter distribution with minimum additional exposure. The results of the scatter correction with angular interpolation were comparable to those of the scatter correction with all scatter distributions at each angle. The exposure increase was less than 13%. This study demonstrated the influence of the scatter correction obtained by using the BSA algorithm with minimum exposure, which indicates its potential for practical applications.

  11. ATLAS IBL Pixel Upgrade

    CERN Document Server

    La Rosa, A

    2011-01-01

    The upgrade for ATLAS detector will undergo different phase towards super-LHC. The first upgrade for the Pixel detector will consist of the construction of a new pixel layer which will be installed during the first shutdown of the LHC machine (LHC phase-I upgrade). The new detector, called Insertable B-Layer (IBL), will be inserted between the existing pixel detector and a new (smaller radius) beam-pipe at a radius of 3.3 cm. The IBL will require the development of several new technologies to cope with increase of radiation or pixel occupancy and also to improve the physics performance which will be achieved by reducing the pixel size and of the material budget. Three different promising sensor technologies (planar-Si, 3D-Si and diamond) are currently under investigation for the pixel detector. An overview of the project with particular emphasis on pixel module is presented in this paper

  12. Compact SPAD-Based Pixel Architectures for Time-Resolved Image Sensors.

    Science.gov (United States)

    Perenzoni, Matteo; Pancheri, Lucio; Stoppa, David

    2016-05-23

    This paper reviews the state of the art of single-photon avalanche diode (SPAD) image sensors for time-resolved imaging. The focus of the paper is on pixel architectures featuring small pixel size (20%) as a key enabling technology for the successful implementation of high spatial resolution SPAD-based image sensors. A summary of the main CMOS SPAD implementations, their characteristics and integration challenges, is provided from the perspective of targeting large pixel arrays, where one of the key drivers is the spatial uniformity. The main analog techniques aimed at time-gated photon counting and photon timestamping suitable for compact and low-power pixels are critically discussed. The main features of these solutions are the adoption of analog counting techniques and time-to-analog conversion, in NMOS-only pixels. Reliable quantum-limited single-photon counting, self-referenced analog-to-digital conversion, time gating down to 0.75 ns and timestamping with 368 ps jitter are achieved.

  13. Compact SPAD-Based Pixel Architectures for Time-Resolved Image Sensors

    Directory of Open Access Journals (Sweden)

    Matteo Perenzoni

    2016-05-01

    Full Text Available This paper reviews the state of the art of single-photon avalanche diode (SPAD image sensors for time-resolved imaging. The focus of the paper is on pixel architectures featuring small pixel size (<25 μm and high fill factor (>20% as a key enabling technology for the successful implementation of high spatial resolution SPAD-based image sensors. A summary of the main CMOS SPAD implementations, their characteristics and integration challenges, is provided from the perspective of targeting large pixel arrays, where one of the key drivers is the spatial uniformity. The main analog techniques aimed at time-gated photon counting and photon timestamping suitable for compact and low-power pixels are critically discussed. The main features of these solutions are the adoption of analog counting techniques and time-to-analog conversion, in NMOS-only pixels. Reliable quantum-limited single-photon counting, self-referenced analog-to-digital conversion, time gating down to 0.75 ns and timestamping with 368 ps jitter are achieved.

  14. Implementation of digital multiplexing for high resolution X-ray detector arrays.

    Science.gov (United States)

    Sharma, P; Swetadri Vasan, S N; Titus, A H; Cartwright, A N; Bednarek, D R; Rudin, S

    2012-01-01

    We describe and demonstrate for the first time the use of the novel Multiple Module Multiplexer (MMMIC) for a 2×2 array of new electron multiplying charge coupled device (EMCCD) based x-ray detectors. It is highly desirable for x-ray imaging systems to have larger fields of view (FOV) extensible in two directions yet to still be capable of doing high resolution imaging over regions-of-interest (ROI). The MMMIC achieves these goals by acquiring and multiplexing data from an array of imaging modules thereby enabling a larger FOV, and at the same time allowing high resolution ROI imaging through selection of a subset of modules in the array. MMMIC also supports different binning modes. This paper describes how a specific two stage configuration connecting three identical MMMICs is used to acquire and multiplex data from a 2×2 array of EMCCD based detectors. The first stage contains two MMMICs wherein each MMMIC is getting data from two EMCCD detectors. The multiplexed data from these MMMICs is then forwarded to the second stage MMMIC in the similar fashion. The second stage that has only one MMMIC gives the final 12 bit multiplexed data from four modules. This data is then sent over a high speed Camera Link interface to the image processing computer. X-ray images taken through the 2×2 array of EMCCD based detectors using this two stage configuration of MMMICs are shown successfully demonstrating the concept.

  15. Submission of the first full scale prototype chip for upgraded ATLAS pixel detector at LHC, FE-I4A

    Energy Technology Data Exchange (ETDEWEB)

    Barbero, Marlon, E-mail: barbero@physik.uni-bonn.de [Physikalisches Institut Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Arutinov, David [Physikalisches Institut Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Beccherle, Roberto; Darbo, Giovanni [INFN Genova, via Dodecaseno 33, IT-16146 Genova (Italy); Dube, Sourabh; Elledge, David; Fleury, Julien [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, CA 94720 (United States); Fougeron, Denis [CPPM Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Garcia-Sciveres, Maurice [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, CA 94720 (United States); Gensolen, Fabrice [CPPM Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Gnani, Dario [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, CA 94720 (United States); Gromov, Vladimir [NIKHEF, Science Park 105, 1098 XG Amsterdam (Netherlands); Jensen, Frank [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, CA 94720 (United States); Hemperek, Tomasz; Karagounis, Michael [Physikalisches Institut Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Kluit, Ruud [NIKHEF, Science Park 105, 1098 XG Amsterdam (Netherlands); Kruth, Andre [Physikalisches Institut Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Mekkaoui, Abderrezak [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, CA 94720 (United States); Menouni, Mohsine [CPPM Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Schipper, Jan David [NIKHEF, Science Park 105, 1098 XG Amsterdam (Netherlands); and others

    2011-09-11

    A new ATLAS pixel chip FE-I4 is being developed for use in upgraded LHC luminosity environments, including the near-term Insertable B-Layer (IBL) upgrade. FE-I4 is designed in a 130 nm CMOS technology, presenting advantages in terms of radiation tolerance and digital logic density compared to the 0.25{mu}m CMOS technology used for the current ATLAS pixel IC, FE-I3. The FE-I4 architecture is based on an array of 80x336 pixels, each 50x250{mu}m{sup 2}, consisting of analog and digital sections. In the summer 2010, a first full scale prototype FE-I4A was submitted for an engineering run. This IC features the full scale pixel array as well as the complex periphery of the future full-size FE-I4. The FE-I4A contains also various extra test features which should prove very useful for the chip characterization, but deviate from the needs for standard operation of the final FE-I4 for IBL. In this paper, focus will be brought to the various features implemented in the FE-I4A submission, while also underlining the main differences between the FE-I4A IC and the final FE-I4 as envisioned for IBL.

  16. Development of a fully programmable ROIC with 15 μm pixel pitch for MWIR applications

    Science.gov (United States)

    Altun, Oguz; Kepenek, Reha; Tasdemir, Ferhat; Akyurek, Fatih; Tunca, Can; Akbulut, Mehmet; Nuzumlali, Omer Lutfi; Inceturkmen, Ercihan

    2017-02-01

    A 15 μm pixel pitch 640×512 Readout Circuit (ROIC) for MWIR applications is designed and fabricated using 0.18 um CMOS process. The ROIC is implemented using Direct Injection (DI) input stage with programmable pixel gain where maximum full-well-capacity (FWC) is more than 13Mé. All analog current and voltage bias values can be programmed through a digital interface. Additionally, integration time can be programmed with 0.1 µsec resolution by internal timing circuitry. ROIC has 1, 2 and 4 output modes with a frame rate of 120fps at 4 output mode. The design supports IntegrateThen-Read (ITR) and Integrate-While-Read (IWR) modes in snapshot operation. Photodetector reverse bias voltage is controlled by adjusting the bias of the common-gate input stage at the input of DI pixel. An on-chip low-dropout voltage regulator is used to generate the detector common voltage. With 2x2 binning feature, the ROIC can also be used for 30 µm pixel pitch 320x256 photodetector arrays. An Analog-Front-End (AFE) card has been designed to operate the ROIC and to convert analog video output to a 14-bit digital value. This digital video data is handled by external video processor card which supports 1-point and 2-point Non-Uniformity Correction (NUC), histogram equalization, bad pixel replacement and filtering. The ROIC has been extensively tested with a prototype FPA at 77°K. According to these test results, functionality of all modes have been verified and a noise level of 700é is achieved at 4.5Mé FWC.

  17. A study in GUI aesthetics for modern pixel art games.

    OpenAIRE

    Grahn, Emma

    2013-01-01

    The clarity and usability of the graphical user interface is very important for the enjoyment of a digital game. Pixel art is an art style with low resolution consisting of a precise placing of pixels, the smallest unit of colour that a screen can display. Pixel art has the potential of being cheap, easy to make and nostalgic, but it takes some skill to handle. However the great weakness of pixel art is displaying letters, and small details with clarity. So is there a place for pixel art in m...

  18. Characterization of the column-based priority logic readout of Topmetal-II‑ CMOS pixel direct charge sensor

    Science.gov (United States)

    An, M.; Zhang, W.; Xiao, L.; Gao, C.; Chen, C.; Han, M.; Huang, G.; Ji, R.; Li, X.; Liu, J.; Mei, Y.; Pei, H.; Sun, Q.; Sun, X.; Wang, K.; Yang, P.; Zhou, W.

    2017-03-01

    We present the detailed study of the digital readout of Topmetal-II- CMOS pixel direct charge sensor. Topmetal-II- is an integrated sensor with an array of 72×72 pixels each capable of directly collecting external charge through exposed metal electrodes in the topmost metal layer. In addition to the time-shared multiplexing readout of the analog output from Charge Sensitive Amplifiers in each pixel, hits are also generated through comparators in each pixel with individually adjustable thresholds. The hits are read out via a column-based priority logic structure, retaining both hit location and time information. The in-array column-based priority logic features with a full clock-less circuitry hence there is no continuously running clock distributed in the pixel and matrix logic. These characteristics enable its use as the charge readout device in future Time Projection Chambers without gaseous gain mechanism, which has unique advantages in low background and low rate-density experiments. We studied the detailed working behavior and performance of this readout, and demonstrated its functional validity and potential in imaging applications.

  19. Single-pixel camera with one graphene photodetector.

    Science.gov (United States)

    Li, Gongxin; Wang, Wenxue; Wang, Yuechao; Yang, Wenguang; Liu, Lianqing

    2016-01-11

    Consumer cameras in the megapixel range are ubiquitous, but the improvement of them is hindered by the poor performance and high cost of traditional photodetectors. Graphene, a two-dimensional micro-/nano-material, recently has exhibited exceptional properties as a sensing element in a photodetector over traditional materials. However, it is difficult to fabricate a large-scale array of graphene photodetectors to replace the traditional photodetector array. To take full advantage of the unique characteristics of the graphene photodetector, in this study we integrated a graphene photodetector in a single-pixel camera based on compressive sensing. To begin with, we introduced a method called laser scribing for fabrication the graphene. It produces the graphene components in arbitrary patterns more quickly without photoresist contamination as do traditional methods. Next, we proposed a system for calibrating the optoelectrical properties of micro/nano photodetectors based on a digital micromirror device (DMD), which changes the light intensity by controlling the number of individual micromirrors positioned at + 12°. The calibration sensitivity is driven by the sum of all micromirrors of the DMD and can be as high as 10(-5)A/W. Finally, the single-pixel camera integrated with one graphene photodetector was used to recover a static image to demonstrate the feasibility of the single-pixel imaging system with the graphene photodetector. A high-resolution image can be recovered with the camera at a sampling rate much less than Nyquist rate. The study was the first demonstration for ever record of a macroscopic camera with a graphene photodetector. The camera has the potential for high-speed and high-resolution imaging at much less cost than traditional megapixel cameras.

  20. Real-time B-scan ultrasonic imaging using a digital phased array system for NDE

    Science.gov (United States)

    Dunki-Jacobs, Robert; Thomas, Lewis

    A demonstration is presented of the ability to produce real-time images of metals on the basis of a phased-array ultrasound system. Attention is given to the critical role played by a beam-former. It is established that the present imaging system's resolution approaches the theoretical capabilities of the given aperture size and wavelength.

  1. Digital Beam Forming and Compressive Sensing Based DOA Estimation in MIMO Arrays

    NARCIS (Netherlands)

    Belfiori, F.; Anitori, L.; Rossum, W.L. van; Otten, M.P.G.; Hoogeboom, P.

    2011-01-01

    The paper presents different processing schemes that have been investigated in order to evaluate the direction of arrival (DOA) with a multiple-input multiple-output (MIMO) radar. Conventional digital beam forming (DBF) and super resolution algorithm (MUSIC) have been applied. The results provided b

  2. Silicon Geiger-mode avalanche photodiode arrays for photon-starved imaging

    Science.gov (United States)

    Aull, Brian F.

    2015-05-01

    Geiger-mode avalanche photodiodes (GMAPDs) are capable of detecting single photons. They can be operated to directly trigger all-digital circuits, so that detection events are digitally counted or time stamped in each pixel. An imager based on an array of GMAPDs therefore has zero readout noise, enabling quantum-limited sensitivity for photon-starved imaging applications. In this review, we discuss devices developed for 3D imaging, wavefront sensing, and passive imaging.

  3. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  4. Extending the dynamic range of silicon photomultipliers without increasing pixel count

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Kurtis F., E-mail: kurtis.johnson@cern.c [Department of Physics, Florida State University, Tallahassee, FL (United States)

    2010-09-21

    A silicon photomultiplier, sometimes called 'multipixel photon counter', which we here refer to as a 'SiPM', is a photo-sensitive device built from an avalanche photodiode array of pixels on a common silicon substrate, such that it can detect single photon events. The dimensions of a pixel may vary from 20 to 100 {mu}m and their density can be greater than 1000 per square millimeter. Each pixel in a SiPM operates in Geiger mode and is coupled to the output by a quenching resistor. Although each pixel operates in digital mode, the SiPM is an analog device because all the pixels are read in parallel, making it possible to generate signals within a dynamic range from a single photon to a large number of photons, ultimately limited by the number of pixels on the chip. In this note we describe a simple and general method of increasing the dynamic range of a SiPM beyond that one may naively assume from the shape of the cumulative distribution function of the SiPM response to the average number of photons per pixel. We show that by rendering the incoming flux of photons to be non-uniform in a prescribed manner, a significant increase in dynamic range is achievable. Such re-distribution of the incoming flux may be accomplished with simple, non-focusing lenses, prisms, interference films, mirrors or attenuating films. Almost any optically non-inert interceding device can increase the dynamic range of the SiPM.

  5. Using Spatially Varying Pixels Exposures and Bayer-covered Photosensors for High Dynamic Range Imaging

    CERN Document Server

    Konnik, Mikhail V

    2008-01-01

    The method of a linear high dynamic range imaging using solid-state photosensors with Bayer colour filters array is provided in this paper. Using information from neighbour pixels, it is possible to reconstruct linear images with wide dynamic range from the oversaturated images. Bayer colour filters array is considered as an array of neutral filters in a quasimonochromatic light. If the camera's response function to the desirable light source is known then one can calculate correction coefficients to reconstruct oversaturated images. Reconstructed images are linearized in order to provide a linear high dynamic range images for optical-digital imaging systems. The calibration procedure for obtaining the camera's response function to the desired light source is described. Experimental results of the reconstruction of the images from the oversaturated images are presented for red, green, and blue quasimonochromatic light sources. Quantitative analysis of the accuracy of the reconstructed images is provided.

  6. A flexible 32-channel time-to-digital converter implemented in a Xilinx Zynq-7000 field programmable gate array

    Science.gov (United States)

    Wang, Yonggang; Kuang, Jie; Liu, Chong; Cao, Qiang; Li, Deng

    2017-03-01

    A high performance multi-channel time-to-digital converter (TDC) is implemented in a Xilinx Zynq-7000 field programmable gate array (FPGA). It can be flexibly configured as either 32 TDC channels with 9.9 ps time-interval RMS precision, 16 TDC channels with 6.9 ps RMS precision, or 8 TDC channels with 5.8 ps RMS precision. All TDCs have a 380 M Samples/second measurement throughput and a 2.63 ns measurement dead time. The performance consistency and temperature dependence of TDC channels are also evaluated. Because Zynq-7000 FPGA family integrates a feature-rich dual-core ARM based processing system and 28 nm Xilinx programmable logic in a single device, the realization of high performance TDCs on it will make the platform more widely used in time-measuring related applications.

  7. Single-exposure two-dimensional superresolution in digital holography using a vertical cavity surface-emitting laser source array.

    Science.gov (United States)

    Granero, Luis; Zalevsky, Zeev; Micó, Vicente

    2011-04-01

    We present a new implementation capable of producing two-dimensional (2D) superresolution (SR) imaging in a single exposure by aperture synthesis in digital lensless Fourier holography when using angular multiplexing provided by a vertical cavity surface-emitting laser source array. The system performs the recording in a single CCD snapshot of a multiplexed hologram coming from the incoherent addition of multiple subholograms, where each contains information about a different 2D spatial frequency band of the object's spectrum. Thus, a set of nonoverlapping bandpass images of the input object can be recovered by Fourier transformation (FT) of the multiplexed hologram. The SR is obtained by coherent addition of the information contained in each bandpass image while generating an enlarged synthetic aperture. Experimental results demonstrate improvement in resolution and image quality.

  8. Note: A high-frequency signal generator based on direct digital synthesizer and field-programmable gate array

    Science.gov (United States)

    Du, Yuanbo; Li, Wenbing; Ge, Yapeng; Li, Hui; Deng, Ke; Lu, Zehuang

    2017-09-01

    A high-frequency signal generator based on direct digital synthesizer (DDS) and field-programmable gate array (FPGA) is presented. The FPGA provides the controlling time sequence for the DDS, which has a highest output frequency of 1.4 GHz and a frequency resolution of 190 pHz. At an output frequency of 1.2 GHz, the measured phase noise, including the contribution of the reference clock, is -65 dBc/Hz@1 Hz, while the intrinsic phase noise is -82 dBc/Hz@1 Hz. Time delay of the DDS is measured to be less than 150 ns. The signal generator is used to drive an acousto-optic modulator, and the rise time due to the whole link is 24 ns. The developed signal generator can be used in many precision measurement experiments in the fields of atomic, molecular, and optical physics.

  9. OAM multiple transmission using uniform circular arrays: numerical modelling and experimental verification with two digital television signals

    CERN Document Server

    Gaffoglio, Rossella; De Vita, Assunta; Sacco, Bruno

    2015-01-01

    In this work we present the outcomes of a radio-frequency OAM transmission between two antenna arrays performed in a real-world context. The analysis is supplemented by deep simulative investigations able to provide both a preliminary overview of the experimental scenario and a posteriori validation of the achieved results. As a first step, the far-field OAM communication link is tested at various frequencies and the corresponding link budget is studied by means of an angular scan generated by the rotation of the receiving system. Then, on the same site, two digital television signals encoded as OAM modes ($\\ell$=1 and $\\ell$=-1) are simultaneously transmitted at a common frequency of 198.5 MHz with good mode insulation.

  10. Development of a sub-nanosecond time-to-digital converter based on a field-programmable gate array

    Science.gov (United States)

    Sano, Y.; Tomoto, M.; Horii, Y.; Sasaki, O.; Uchida, T.; Ikeno, M.

    2016-03-01

    The present time-to-digital converter (TDC) chips for the monitored drift tube (MDT) chambers at the ATLAS experiment will be replaced with new ones for the High-Luminosity LHC, expected to begin operation in 2026. The design and the performance of a 24 channel TDC with a variable time binning of down to 0.28 nsec based on a Xilinx Kintex-7 field programmable gate array are reported. The time measurement is provided by a multisampling scheme with quad phase clocks synchronized with an external reference clock. The differential and integral nonlinearities have been measured to be less than half of the time binning. The temperature dependence on the performance is observed to be small. In conclusion the obtained performance of the time measurement is sufficiently high for the use with MDT chambers.

  11. OAM multiple transmission using uniform circular arrays: Numerical modeling and experimental verification with two digital television signals

    Science.gov (United States)

    Gaffoglio, Rossella; Cagliero, Andrea; Vita, Assunta De; Sacco, Bruno

    2016-06-01

    In this work we present the outcomes of a radio frequency orbital angular momentum (OAM) transmission between two antenna arrays performed in a real-world context. The analysis is supplemented by deep simulative investigations able to provide both a preliminary overview of the experimental scenario and a posteriori validation of the achieved results. As a first step, the far-field OAM communication link is tested at various frequencies and the corresponding link budget is studied by means of an angular scan generated by the rotation of the receiving system. Then, on the same site, two digital television signals encoded as OAM modes (ℓ = 1 and ℓ =- 1) are simultaneously transmitted at a common frequency of 198.5 MHz with good mode insulation.

  12. FlashCam: a fully-digital camera for the medium-sized telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Pühlhofer, G; Bernhard, S; Capasso, M; Diebold, S; Eisenkolb, F; Florin, D; Föhr, C; Funk, S; Gadola, A; Garrecht, F; Hermann, G; Jung, I; Kalekin, O; Kalkuhl, C; Kasperek, J; Kihm, T; Lahmann, R; Manalaysay, A; Marszalek, A; Pfeifer, M; Rajda, P J; Reimer, O; Santangelo, A; Schanz, T; Schwab, T; Steiner, S; Straumann, U; Tenzer, C; Vollhardt, A; Weitzel, Q; Werner, F; Wolf, D; Zietara, K

    2015-01-01

    The FlashCam group is currently preparing photomultiplier-tube based cameras proposed for the medium-sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The cameras are designed around the FlashCam readout concept which is the first fully-digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for the front-end electronics modules and a high performance camera server as back-end. This contribution describes the progress of the full-scale FlashCam camera prototype currently under construction, as well as performance results also obtained with earlier demonstrator setups. Plans towards the production and implementation of FlashCams on site are also briefly presented.

  13. Active Pixel Sensors: Are CCD's Dinosaurs?

    Science.gov (United States)

    Fossum, Eric R.

    1993-01-01

    Charge-coupled devices (CCD's) are presently the technology of choice for most imaging applications. In the 23 years since their invention in 1970, they have evolved to a sophisticated level of performance. However, as with all technologies, we can be certain that they will be supplanted someday. In this paper, the Active Pixel Sensor (APS) technology is explored as a possible successor to the CCD. An active pixel is defined as a detector array technology that has at least one active transistor within the pixel unit cell. The APS eliminates the need for nearly perfect charge transfer -- the Achilles' heel of CCDs. This perfect charge transfer makes CCD's radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response.

  14. Low-power high-accuracy micro-digital sun sensor by means of a CMOS image sensor

    NARCIS (Netherlands)

    Xie, N.; Theuwissen, A.J.P.

    2013-01-01

    A micro-digital sun sensor (μDSS) is a sun detector which senses a satellite’s instant attitude angle with respect to the sun. The core of this sensor is a system-on-chip imaging chip which is referred to as APS+. The APS+ integrates a CMOS active pixel sensor (APS) array of 368×368  pixels , a 12-b

  15. Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits

    Science.gov (United States)

    2016-01-20

    bump bonds or through-silicon vias used in some wafer stacking processes. The process can be...function as bump bonds, but are much smaller) are patterned on each wafer and planarized along with the bonding oxide. When the wafers are bonded and...pads, the APD array is integrated with a CMOS readout circuit, using either bump bonding or a 3D integration technique. During this process

  16. 1-D Systolic Arrays Design of LMS Adaptive (FIR Digital Filtering

    Directory of Open Access Journals (Sweden)

    Ali H. Mahdi

    2010-01-01

    Full Text Available This paper extends the 1-D systolic array approach with a method of systematic linear design of systolic algorithms. Past methods for mapping the Least-Mean-Square (LMS Adaptive Finite-Impulse-Response (FIR filter onto parallel and pipelined architectures either introduce delays in the coefficients updates or have excessive hardware requirements. In this article, we describe an efficient 1-D systolic array for the LMS adaptive FIR filter that produces the same output and error signals as produced by the standard LMS adaptive filter architecture with single assignment form of processor functions.The proposed systolic architectures that are designed operate on a block-by-block basis and makes use of the flexibility in the design, which takes the inner product step (convolution sum of the tap weight vector and the tap input vector in the design consideration. It enables us to extract more than one algorithm for the same problem. The input and output data flow sequentially and continuously into and out of the systolic arrays at the system clock rates, during each clock period, processing element of the same type operates in parallel. The most computationally demanding among them performs only two consecutive multiplications and two additions/subtractions per clock period, thereby allowing a very high throughput and very fast block signal processing to be achieved at the expense of a delay of L samples between the input and output and 100% utilization, L being the block size.

  17. Toward VIP-PIX: A Low Noise Readout ASIC for Pixelated CdTe Gamma-Ray Detectors for Use in the Next Generation of PET Scanners.

    Science.gov (United States)

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Puigdengoles, Carles; Lorenzo, Gianluca De; Martínez, Ricardo

    2013-08-01

    VIP-PIX will be a low noise and low power pixel readout electronics with digital output for pixelated Cadmium Telluride (CdTe) detectors. The proposed pixel will be part of a 2D pixel-array detector for various types of nuclear medicine imaging devices such as positron-emission tomography (PET) scanners, Compton gamma cameras, and positron-emission mammography (PEM) scanners. Each pixel will include a SAR ADC that provides the energy deposited with 10-bit resolution. Simultaneously, the self-triggered pixel which will be connected to a global time-to-digital converter (TDC) with 1 ns resolution will provide the event's time stamp. The analog part of the readout chain and the ADC have been fabricated with TSMC 0.25 μm mixed-signal CMOS technology and characterized with an external test pulse. The power consumption of these parts is 200 μW from a 2.5 V supply. It offers 4 switchable gains from ±10 mV/fC to ±40 mV/fC and an input charge dynamic range of up to ±70 fC for the minimum gain for both polarities. Based on noise measurements, the expected equivalent noise charge (ENC) is 65 e(-) RMS at room temperature.

  18. Synchronization sampling method based on delta-sigma analog-digital converter for underwater towed array system

    Science.gov (United States)

    Jiang, Jia-Jia; Duan, Fa-Jie; Li, Yan-Chao; Hua, Xiang-Ning

    2014-03-01

    Synchronization sampling is very important in underwater towed array system where every acquisition node (AN) samples analog signals by its own analog-digital converter (ADC). In this paper, a simple and effective synchronization sampling method is proposed to ensure synchronized operation among different ANs of the underwater towed array system. We first present a master-slave synchronization sampling model, and then design a high accuracy phase-locked loop to synchronize all delta-sigma ADCs to a reference clock. However, when the master-slave synchronization sampling model is used, both the time-delay (TD) of messages traveling along the wired transmission medium and the jitter of the clocks will bring out synchronization sampling error (SSE). Therefore, a simple method is proposed to estimate and compensate the TD of the messages transmission, and then another effective method is presented to overcome the SSE caused by the jitter of the clocks. An experimental system with three ANs is set up, and the related experimental results verify the validity of the synchronization sampling method proposed in this paper.

  19. A highly addressable static droplet array enabling digital control of a single droplet at pico-volume resolution.

    Science.gov (United States)

    Jeong, Heon-Ho; Lee, Byungjin; Jin, Si Hyung; Jeong, Seong-Geun; Lee, Chang-Soo

    2016-04-26

    Droplet-based microfluidics enabling exquisite liquid-handling has been developed for diagnosis, drug discovery and quantitative biology. Compartmentalization of samples into a large number of tiny droplets is a great approach to perform multiplex assays and to improve reliability and accuracy using a limited volume of samples. Despite significant advances in microfluidic technology, individual droplet handling in pico-volume resolution is still a challenge in obtaining more efficient and varying multiplex assays. We present a highly addressable static droplet array (SDA) enabling individual digital manipulation of a single droplet using a microvalve system. In a conventional single-layer microvalve system, the number of microvalves required is dictated by the number of operation objects; thus, individual trap-and-release on a large-scale 2D array format is highly challenging. By integrating double-layer microvalves, we achieve a "balloon" valve that preserves the pressure-on state under released pressure; this valve can allow the selective releasing and trapping of 7200 multiplexed pico-droplets using only 1 μL of sample without volume loss. This selectivity and addressability completely arranged only single-cell encapsulated droplets from a mixture of droplet compositions via repetitive selective trapping and releasing. Thus, it will be useful for efficient handling of miniscule volumes of rare or clinical samples in multiplex or combinatory assays, and the selective collection of samples.

  20. Precision charge amplification and digitization system for a scintillating and lead glass array

    Energy Technology Data Exchange (ETDEWEB)

    Delchamps, S.W.; Rameika, R.; Arenton, M.; Chen, T.Y.; Conetti, S.; Cox, B.; Etemadi, B.; Fortney, L.; Guffey, K.; Haire, M.

    1989-01-01

    A 544-channel low-noise, high-rate, precision charge amplification and ADC system was constructed for the Fermilab Experiment 705 electromagnetic calorimeter, which employs SCG1-C scintillating glass and SF5 lead glass instrumented with photo-multiplier tubes. A general discussion of the system is given, and the charge amplification, fast trigger pulse generation, and analog to digital conversion aspects of the system are presented in more detail. Performance is evaluated using data from Experiment 705 and from off-line tests. Short and long term pedestal stability, baseline recovery and rate capability, linearity of response, and crosstalk between channels are discussed. 8 refs., 2 tabs.

  1. Modeling and analysis of hybrid pixel detector deficiencies for scientific applications

    Science.gov (United States)

    Fahim, Farah; Deptuch, Grzegorz W.; Hoff, James R.; Mohseni, Hooman

    2015-08-01

    Semiconductor hybrid pixel detectors often consist of a pixellated sensor layer bump bonded to a matching pixelated readout integrated circuit (ROIC). The sensor can range from high resistivity Si to III-V materials, whereas a Si CMOS process is typically used to manufacture the ROIC. Independent, device physics and electronic design automation (EDA) tools are used to determine sensor characteristics and verify functional performance of ROICs respectively with significantly different solvers. Some physics solvers provide the capability of transferring data to the EDA tool. However, single pixel transient simulations are either not feasible due to convergence difficulties or are prohibitively long. A simplified sensor model, which includes a current pulse in parallel with detector equivalent capacitor, is often used; even then, spice type top-level (entire array) simulations range from days to weeks. In order to analyze detector deficiencies for a particular scientific application, accurately defined transient behavioral models of all the functional blocks are required. Furthermore, various simulations, such as transient, noise, Monte Carlo, inter-pixel effects, etc. of the entire array need to be performed within a reasonable time frame without trading off accuracy. The sensor and the analog front-end can be modeling using a real number modeling language, as complex mathematical functions or detailed data can be saved to text files, for further top-level digital simulations. Parasitically aware digital timing is extracted in a standard delay format (sdf) from the pixel digital back-end layout as well as the periphery of the ROIC. For any given input, detector level worst-case and best-case simulations are performed using a Verilog simulation environment to determine the output. Each top-level transient simulation takes no more than 10-15 minutes. The impact of changing key parameters such as sensor Poissonian shot noise, analog front-end bandwidth, jitter due to

  2. Modeling and Analysis of Hybrid Pixel Detector Deficiencies for Scientific Applications

    Energy Technology Data Exchange (ETDEWEB)

    Fahim, Farah [Northwestern U. (main); Deptuch, Grzegorz W. [Fermilab; Hoff, James R. [Fermilab; Mohseni, Hooman [Northwestern U. (main)

    2015-08-28

    Semiconductor hybrid pixel detectors often consist of a pixellated sensor layer bump bonded to a matching pixelated readout integrated circuit (ROIC). The sensor can range from high resistivity Si to III-V materials, whereas a Si CMOS process is typically used to manufacture the ROIC. Independent, device physics and electronic design automation (EDA) tools are used to determine sensor characteristics and verify functional performance of ROICs respectively with significantly different solvers. Some physics solvers provide the capability of transferring data to the EDA tool. However, single pixel transient simulations are either not feasible due to convergence difficulties or are prohibitively long. A simplified sensor model, which includes a current pulse in parallel with detector equivalent capacitor, is often used; even then, spice type top-level (entire array) simulations range from days to weeks. In order to analyze detector deficiencies for a particular scientific application, accurately defined transient behavioral models of all the functional blocks are required. Furthermore, various simulations, such as transient, noise, Monte Carlo, inter-pixel effects, etc. of the entire array need to be performed within a reasonable time frame without trading off accuracy. The sensor and the analog front-end can be modeling using a real number modeling language, as complex mathematical functions or detailed data can be saved to text files, for further top-level digital simulations. Parasitically aware digital timing is extracted in a standard delay format (sdf) from the pixel digital back-end layout as well as the periphery of the ROIC. For any given input, detector level worst-case and best-case simulations are performed using a Verilog simulation environment to determine the output. Each top-level transient simulation takes no more than 10-15 minutes. The impact of changing key parameters such as sensor Poissonian shot noise, analog front-end bandwidth, jitter due to

  3. Architectural modeling of pixel readout chips Velopix and Timepix3

    NARCIS (Netherlands)

    Poikela, T.; Plosila, J.; Westerlund, T.; Buytaert, J.; Campbell, M.; Llopart, X.; Plackett, R.; Wyllie, K.; van Beuzekom, M.; Gromov, V.; Kluit, R.; Zappon, F.; Zivkovic, V.; Brezina, C.; Desch, K.; Fang, X.; Kruth, A.

    2012-01-01

    We examine two digital architectures for front end pixel readout chips, Velopix and Timepix3. These readout chips are developed for tracking detectors in future high energy physics experiments. They must incorporate local intelligence in pixels for time-over-threshold measurement and sparse readout.

  4. Monolithic CMOS pixel detector for international linear collider vertex detection

    Indian Academy of Sciences (India)

    J E Brau; O Igonkina; N Sinew; D Strom; C Baltay; W Emmet; H Neal; D Rabinowitz

    2007-12-01

    A monolithic CMS pixel detector is under development for an ILC experiment. This chronopixel array provides a time stamp resolution of one bunch crossing, a critical feature for background suppression. The status of this effort is summarized.

  5. Content Progressive Coding of Limited Bits/pixel Images

    DEFF Research Database (Denmark)

    Jensen, Ole Riis; Forchhammer, Søren

    1999-01-01

    A new lossless context based method for content progressive coding of limited bits/pixel images is proposed. Progressive coding is achieved by separating the image into contelnt layers. Digital maps are compressed up to 3 times better than GIF.......A new lossless context based method for content progressive coding of limited bits/pixel images is proposed. Progressive coding is achieved by separating the image into contelnt layers. Digital maps are compressed up to 3 times better than GIF....

  6. A Three-Dimensional Position Architecture Using Digital TDE Receiver and Cylindrical Array Antenna

    Directory of Open Access Journals (Sweden)

    J. Mar

    2013-03-01

    Full Text Available The robust three-dimensional position architecture is proposed in the paper, where the hybrid time difference of arrival(TDOA and direction of arrival (DOA position system was designed to backup the four-station TDOA positionsystem. The digital time delay estimation (TDE receiver is used for TDOA measurement and the cylindrical arrayantenna is used for DOA measurement. The general formula of linear phase compensation for cylindrical arrayantenna in horizontal plane is derived. The detection probability of the TDE receiver and the circular error probability(CEP of the position systems over Rayleigh fading channel were numerically computed in three-dimensional space.Simulations indicate that the position accuracy of the four-station TDOA position system is degraded but the locationfunction can be retained by the hybrid TDOA and DOA position system when any one of four-stations is out of work.

  7. Field Programmable DSP Arrays - A Novel Reconfigurable Architecture for Efficient Reliazation of Digital Signal Processing Functions

    Directory of Open Access Journals (Sweden)

    Amitabha Sinha

    2013-04-01

    Full Text Available Digital Signal Processing functions are widely used in real time high speed applications. Those functions are generally implemented either on ASICs with inflexibility, or on FPGAs with bottlenecks of relatively smaller utilization factor or lower speed compared to ASIC. The proposed reconfigurable DSP processor is redolent to FPGA, but with basic fixed Common Modules (CMs (like adders, subtractors, multipliers, scaling units, shifters instead of CLBs. This pape r introduces the development of a reconfigurable DSP processor that integrates different filter and transform functions. The switching between DSP functions is occurred by reconfiguring the interconnection between CMs. Validation of the proposed reconfigurable architecture has been achieved on Virtex5 FPGA. The architecture provides sufficient amount of flexibility, parallelism and scalability.

  8. Amorphous silicon pixel layers with cesium iodide converters for medical radiography

    Energy Technology Data Exchange (ETDEWEB)

    Jing, T.; Cho, G. [Lawrence Berkeley Lab., CA (United States); Goodman, C.A. [Air Techniques, Inc., Hicksville, NY (United States)] [and others

    1993-11-01

    We describe the properties of evaporated layers of Cesium Iodide (Thallium activated) deposited on substrates that enable easy coupling to amorphous silicon pixel arrays. The CsI(Tl) layers range in thickness from 65 to 220{mu}m. We used the two-boat evaporator system to deposit CsI(Tl) layers. This system ensures the formation of the scintillator film with homogenous thallium concentration which is essential for optimizing the scintillation light emission efficiency. The Tl concentration was kept to 0.1--0.2 mole percent for the highest light output. Temperature annealing can affect the microstructure as well as light output of the CsI(Tl) film. 200--300C temperature annealing can increase the light output by a factor of two. The amorphous silicon pixel arrays are p-i-n diodes approximately l{mu}m thick with transparent electrodes to enable them to detect the scintillation light produced by X-rays incident on the CsI(Tl). Digital radiography requires a good spatial resolution. This is accomplished by making the detector pixel size less then 50{mu}m. The light emission from the CsI(Tl) is collimated by techniques involving the deposition process on pattered substrates. We have measured MTF of greater than 12 line pairs per mm at the 10% level.

  9. Fully integrated system-on-chip for pixel-based 3D depth and scene mapping

    Science.gov (United States)

    Popp, Martin; De Coi, Beat; Thalmann, Markus; Gancarz, Radoslav; Ferrat, Pascal; Dürmüller, Martin; Britt, Florian; Annese, Marco; Ledergerber, Markus; Catregn, Gion-Pol

    2012-03-01

    We present for the first time a fully integrated system-on-chip (SoC) for pixel-based 3D range detection suited for commercial applications. It is based on the time-of-flight (ToF) principle, i.e. measuring the phase difference of a reflected pulse train. The product epc600 is fabricated using a dedicated process flow, called Espros Photonic CMOS. This integration makes it possible to achieve a Quantum Efficiency (QE) of >80% in the full wavelength band from 520nm up to 900nm as well as very high timing precision in the sub-ns range which is needed for exact detection of the phase delay. The SoC features 8x8 pixels and includes all necessary sub-components such as ToF pixel array, voltage generation and regulation, non-volatile memory for configuration, LED driver for active illumination, digital SPI interface for easy communication, column based 12bit ADC converters, PLL and digital data processing with temporary data storage. The system can be operated at up to 100 frames per second.

  10. The pixelated detector

    CERN Multimedia

    Sutton, C

    1990-01-01

    "Collecting data as patterns of light or subatomic particles is vitally important in all the sciences. The new generation of solid-state detectors called pixel devices could transform experimental research at all levels" (4 pages).

  11. Efficient control structures for digital programmable retinas

    Science.gov (United States)

    Bernard, Thierry M.

    2001-05-01

    A digital programmable artificial retina (PAR) is a functional extension of a CMOS imager, in which every pixel is fitted with a local ADC and a tiny digital programmable processor. From an architectural viewpoint, a PAR is an SIMD array processor with local optical input. A PAR is aimed at processing images on-site until they can be output from the array under concentrated form. The overall goal is to get compact, fast and inexpensive vision systems, in particular for robotics applications. A 256 by 256 PAR with up to a few tens bits of local memory per pixel is now within reach at reasonable cost. However, whereas the local memory size benefits quadratically from the feature size decrease, wiring density improvement can only be linear, at best. So control should become more complex with the danger of a growing proportion of the digital pixel area being devoted to instruction or address decoding. We propose efficient scalable solutions to this problem at the architectural, circuit and topological levels, which attempt to minimize both silicon area and power consumption.

  12. Multiport solid-state imager characterization at variable pixel rates

    Science.gov (United States)

    Yates, George J.; Albright, Kevin L.; Turko, Bojan T.

    1993-10-01

    The imaging performance of an 8-port Full Frame Transfer Charge Coupled Device (FFT CCD) as a function of several parameters including pixel clock rate is presented. The device, model CCD-13, manufactured by English Electric Valve (EEV), is a 512 X 512 pixel array designed with four individual programmable bidirectional serial registers and eight output amplifiers permitting simultaneous readout of eight segments (128 horizontal X 256 vertical pixels) of the array. The imager was evaluated in Los Alamos National Laboratory's High-Speed Solid-State Imager Test Station at true pixel rates as high as 50 MHz for effective imager pixel rates approaching 400 MHz from multiporting. Key response characteristics measured include absolute responsivity, Charge-Transfer-Efficiency (CTE), dynamic range, resolution, signal-to-noise ratio, and electronic and optical crosstalk among the eight video channels. Preliminary test results and data obtained from the CCD-13 are presented and the versatility/capabilities of the test station are reviewed.

  13. Fabrication and Test of Pixelated CZT Detectors with Different Pixel Pitches and Thicknesses

    CERN Document Server

    Li, Q; Dowkontt, P; Martín, J; Beilicke, M; Jung, I; Groza, M; Bürger, A; De Geronimo, G; Krawczynski, H

    2008-01-01

    The main methods grown Cadmium Zinc Telluride (CZT) crystals with high yield and excellent homogeneity are Modified Horizontal Bridgman (MHB) and High Pressure Bridgman (HPB) processes, respectively. In this contribution, the readout system based on two 32-channel NCI-ASICs for pixellated CZT detector arrays has been developed and tested. The CZT detectors supplied by Orbotech (MHB) and eV products (HPB) are tested by NCI-ASIC readout system. The CZT detectors have an array of 8x8 or 11x11 pixel anodes fabricated on the anode surface with the area up to 2 cm x2 cm and the thickness of CZT detectors ranges from 0.5 cm to 1 cm. Energy spectra resolution and electron mobility-lifetime products of 8x8 pixels CZT detector with different thicknesses have been investigated.

  14. High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy.

    Science.gov (United States)

    Lai, Y W; Hamann, S; Ehmann, M; Ludwig, A

    2011-06-01

    We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent.

  15. Test of digital neutron–gamma discrimination with four different photomultiplier tubes for the NEutron Detector Array (NEDA)

    Energy Technology Data Exchange (ETDEWEB)

    Luo, X.L., E-mail: luo.xiaoliang@physics.uu.se [Department of Instrument Science and Technology, College of Mechatronics and Automation, National University of Defense Technology, Changsha (China); Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Modamio, V. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Padova (Italy); Nyberg, J. [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Valiente-Dobón, J.J. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Padova (Italy); Nishada, Q. [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Angelis, G. de [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Padova (Italy); Agramunt, J. [IFIC-CSIC, University of Valencia, Valencia (Spain); Egea, F.J. [IFIC-CSIC, University of Valencia, Valencia (Spain); Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, Istanbul (Turkey); Erduran, M.N.; Ertürk, S. [Nigde Universitesi, Fen-Edebiyat Falkültesi, Fizik Bölümü, Nigde (Turkey); France, G. de [GANIL, CEA/DSAM and CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 05 (France); Gadea, A. [IFIC-CSIC, University of Valencia, Valencia (Spain); González, V. [Department of Electronic Engineering, University of Valencia, E-46071 Valencia (Spain); Hüyük, T. [IFIC-CSIC, University of Valencia, Valencia (Spain); Jaworski, G. [Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warszawa (Poland); Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, 02-093 Warszawa (Poland); Moszyński, M. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5A, 02-093 Warszawa (Poland); National Centre for Nuclear Research, A. Soltana 7, PL 05-400 Otwock-Swierk (Poland); and others

    2014-12-11

    A comparative study of the neutron–γ discrimination performance of a liquid scintillator detector BC501A coupled to four different 5 in. photomultiplier tubes (ET9390kb, R11833-100, XP4512 and R4144) was carried out. Both the Charge Comparison method and the Integrated Rise-Time method were implemented digitally to discriminate between neutrons and γ rays emitted by a {sup 252}Cf source. In both methods, the neutron–γ discrimination capabilities of the four photomultiplier tubes were quantitatively compared by evaluating their figure-of-merit values at different energy regions between 50 keVee and 1000 keVee. Additionally, the results were further verified qualitatively using time-of-flight to distinguish γ rays and neutrons. The results consistently show that photomultiplier tubes R11833-100 and ET9390kb generally perform best regarding neutron–γ discrimination with only slight differences in figure-of-merit values. This superiority can be explained by their relatively higher photoelectron yield, which indicates that a scintillator detector coupled to a photomultiplier tube with higher photoelectron yield tends to result in better neutron–γ discrimination performance. The results of this work will provide reference for the choice of photomultiplier tubes for future neutron detector arrays like NEDA.

  16. 毫米波多像元固态阵列接收机系统方案及关键技术%The System Solutions and Key Technology of a Millimeter-Wave Multi-Pixel Solid-State Array Receiver

    Institute of Scientific and Technical Information of China (English)

    陈翔; 李小军; 陈振华; 葛俊祥

    2016-01-01

    The basic concept and principle of multi-pixel array receivers are introduced in this paper. A G-band multi-pixel array receiver for space application is proposed, of which the structure and performance are presented, and the key technology of the receiver is discussed. Using integrated design method, a 2 × 2 multi-pixel array receiver operating at 183GHz is designed based on solid state nonlinear devices. The input local oscillator is Ku band signal, sideband separating is adopted in this array receiver. The whole receiver is integrated and compact, which can be widely used in many kinds of passive millimeter-wave imaging system.%文章介绍了毫米波多像元阵列接收机原理、技术优势及发展现状。针对空间应用,提出了一种基于固态器件的G波段毫米波多像元阵列接收机结构,并介绍了其关键技术。以固态器件为核心,通过本振变频一体化集成设计思想,设计实现一种中心频率183GHz的2×2像元固态阵列接收机。本振输入为Ku波段信号,接收机采用直接边带分离混频方式。整个接收机模块小型紧凑,可靠性高,可用于各种空间毫米波、亚毫米波无源探测系统中。

  17. Per-Pixel Lighting Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Inanici, Mehlika

    2005-08-01

    This report presents a framework for per-pixel analysis of the qualitative and quantitative aspects of luminous environments. Recognizing the need for better lighting analysis capabilities and appreciating the new measurement abilities developed within the LBNL Lighting Measurement and Simulation Toolbox, ''Per-pixel Lighting Data Analysis'' project demonstrates several techniques for analyzing luminance distribution patterns, luminance ratios, adaptation luminance and glare assessment. The techniques are the syntheses of the current practices in lighting design and the unique practices that can be done with per-pixel data availability. Demonstrated analysis techniques are applicable to both computer-generated and digitally captured images (physically-based renderings and High Dynamic Range photographs).

  18. Characterization of Pixel Sensors

    CERN Document Server

    Oliveira, Felipe Ferraz

    2017-01-01

    It was commissioned at CERN ATLAS pixel group a fluorescence setup for characterization of pixel sensors. The idea is to measure the energies of different targets to calibrate your sensor. It was measured four matrices (80, 95, 98 and 106) of the Investigator1 sensor with different deep PW using copper, iron and titanium as target materials. The matrix 80 has a higher gain (0.065 ± 0.002) and matrix 106 has a better energy resolution (0.05 ± 0.04). The noise of the setup is around 3.6 mV .

  19. ACS/WFC Pixel History, Bringing the Pixels Back to Science

    Science.gov (United States)

    Borncamp, David; Grogin, Norman; Bourque, Matthew; Ogaz, Sara

    2017-06-01

    Excess thermal energy within a Charged Coupled Device (CCD) results in excess electrical current that is trapped within the lattice structure of the electronics. This excess signal from the CCD itself can be present through multiple exposures, which will have an adverse effect on its science performance unless it is corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as ``dark'' images, allow for the measurement of thermal-electron contamination at each pixel of the CCD. This so-called ``dark current'' can then be subtracted from the science images by re-scaling to the science exposure times. Pixels that have signal above a certain value are traditionally marked as ``hot'' and flagged in the data quality array. Many users will discard these pixels as being bad. However, these pixels may not be bad in the sense that they cannot be reliably dark-subtracted; if these pixels are shown to be stable over a given anneal period, the charge can be properly subtracted and the extra Poisson noise from this dark current can be taken into account and put into the error arrays.

  20. Giga-pixel lensfree holographic microscopy and tomography using color image sensors.

    Directory of Open Access Journals (Sweden)

    Serhan O Isikman

    Full Text Available We report Giga-pixel lensfree holographic microscopy and tomography using color sensor-arrays such as CMOS imagers that exhibit Bayer color filter patterns. Without physically removing these color filters coated on the sensor chip, we synthesize pixel super-resolved lensfree holograms, which are then reconstructed to achieve ~350 nm lateral resolution, corresponding to a numerical aperture of ~0.8, across a field-of-view of ~20.5 mm(2. This constitutes a digital image with ~0.7 Billion effective pixels in both amplitude and phase channels (i.e., ~1.4 Giga-pixels total. Furthermore, by changing the illumination angle (e.g., ± 50° and scanning a partially-coherent light source across two orthogonal axes, super-resolved images of the same specimen from different viewing angles are created, which are then digitally combined to synthesize tomographic images of the object. Using this dual-axis lensfree tomographic imager running on a color sensor-chip, we achieve a 3D spatial resolution of ~0.35 µm × 0.35 µm × ~2 µm, in x, y and z, respectively, creating an effective voxel size of ~0.03 µm(3 across a sample volume of ~5 mm(3, which is equivalent to >150 Billion voxels. We demonstrate the proof-of-concept of this lensfree optical tomographic microscopy platform on a color CMOS image sensor by creating tomograms of micro-particles as well as a wild-type C. elegans nematode.

  1. Pixel detector insertion

    CERN Multimedia

    CMS

    2015-01-01

    Insertion of the Pixel Tracker, the 66-million-channel device used to pinpoint the vertex of each colliding proton pair, located at the heart of the detector. The geometry of CMS is a cylinder lying on its side (22 meters long and 15 meters high in dia

  2. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  3. ALICE Silicon Pixel Detector

    CERN Multimedia

    Manzari, V

    2013-01-01

    The Silicon Pixel Detector (SPD) forms the innermost two layers of the 6-layer barrel Inner Tracking System (ITS). The SPD plays a key role in the determination of the position of the primary collision and in the reconstruction of the secondary vertices from particle decays.

  4. ACS/WFC Pixel Stability - Bringing the Pixels Back to the Science

    Science.gov (United States)

    Borncamp, David; Grogin, Norman A.; Bourque, Matthew; Ogaz, Sara

    2016-06-01

    Electrical current that has been trapped within the lattice structure of a Charged Coupled Device (CCD) can be present through multiple exposures, which will have an adverse effect on its science performance. The traditional way to correct for this extra charge is to take an image with the camera shutter closed periodically throughout the lifetime of the instrument. These images, generally referred to as dark images, allow for the characterization of the extra charge that is trapped within the CCD at the time of observation. This extra current can then be subtracted out of science images to correct for the extra charge that was there at this time. Pixels that have a charge above a certain threshold of current are marked as “hot” and flagged in the data quality array. However, these pixels may not be "bad" in the traditional sense that they cannot be reliably dark-subtracted. If these pixels are shown to be stable over an anneal period, the charge can be properly subtracted and the extra noise from this dark current can be taken into account. We present the results of a pixel history study that analyzes every pixel of ACS/WFC individually and allows pixels that were marked as bad to be brought back into the science image.

  5. Ultrasounic digital phased array dynamic focusing system%超声数字式相控阵换能器动态聚焦系统研制

    Institute of Scientific and Technical Information of China (English)

    刘晨; 魏炜; 姜永亮; 汪承灏; 祖庆夕; 平云轩

    2000-01-01

    本文是研制超声相控阵换能器动态聚焦系统,它包括数字式多通道信号发射系统和两种超声相控阵换能器。用数字式多通道信号发射系统产生多路数字信号,通 过改变每路信号的时延(相位),控制相控阵换能器的各个阵元,使它们发出的声束在空间某点聚焦。我们对这两种相控阵进行了实验测量,结果表明,用数字控 制的相控阵换能器,可以实现精密的动态聚焦,并可取得良好的聚焦效果。%This paper focuses on developing a digital ultrasonic phased array transducer system which can realize the focusing and scanning of sound beams. The system consists of a digital multichannel transmitting circuit and two kinds of ultrasonic phased array transducers. Sound beams, produced by the array elements, can be focused onto a point by using this digital transmitting circuit to control the signal phase of each channel. Experimental results indicate that the phased array transducers can realize dynamic focusing with high precision.

  6. Microlens performance limits in sub-2mum pixel CMOS image sensors.

    Science.gov (United States)

    Huo, Yijie; Fesenmaier, Christian C; Catrysse, Peter B

    2010-03-15

    CMOS image sensors with smaller pixels are expected to enable digital imaging systems with better resolution. When pixel size scales below 2 mum, however, diffraction affects the optical performance of the pixel and its microlens, in particular. We present a first-principles electromagnetic analysis of microlens behavior during the lateral scaling of CMOS image sensor pixels. We establish for a three-metal-layer pixel that diffraction prevents the microlens from acting as a focusing element when pixels become smaller than 1.4 microm. This severely degrades performance for on and off-axis pixels in red, green and blue color channels. We predict that one-metal-layer or backside-illuminated pixels are required to extend the functionality of microlenses beyond the 1.4 microm pixel node.

  7. Smart trigger logic for focal plane arrays

    Science.gov (United States)

    Levy, James E; Campbell, David V; Holmes, Michael L; Lovejoy, Robert; Wojciechowski, Kenneth; Kay, Randolph R; Cavanaugh, William S; Gurrieri, Thomas M

    2014-03-25

    An electronic device includes a memory configured to receive data representing light intensity values from pixels in a focal plane array and a processor that analyzes the received data to determine which light values correspond to triggered pixels, where the triggered pixels are those pixels that meet a predefined set of criteria, and determines, for each triggered pixel, a set of neighbor pixels for which light intensity values are to be stored. The electronic device also includes a buffer that temporarily stores light intensity values for at least one previously processed row of pixels, so that when a triggered pixel is identified in a current row, light intensity values for the neighbor pixels in the previously processed row and for the triggered pixel are persistently stored, as well as a data transmitter that transmits the persistently stored light intensity values for the triggered and neighbor pixels to a data receiver.

  8. ATLAS ITk Pixel detector

    CERN Document Server

    Gemme, Claudia; The ATLAS collaboration

    2016-01-01

    The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenge to the ATLAS tracker. The current inner detector will be replaced with a whole silicon tracker which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation level are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the HL-LHC ATLA Pixel detector developments as well as the various layout options will be reviewed.

  9. Alpine Pixel Detector Layout

    CERN Document Server

    Delebecque, P; The ATLAS collaboration; Geffroy, N; Massol, N; Rambure, T; Todorov, T

    2013-01-01

    A description of an optimized layout of pixel sensors based on a stave that combines both barrel and endcap module orientations. The mechanical stiffness of the structure is provided by carbon fiber shells spaced by carbon foam. The cooling of the modules is provided by two-phase $CO_{2}$ flowing in a thin titanium pipe glued inside the carbon fiber foam. The electrical services of all modules are provided by a single stave flex. This layout eliminates the need for separate barrel and endcap detector structures, and therefore the barrel services material in front of the endcap. The transition from barrel to endcap module orientation is optimized separately for each layer in order to minimize the active pixel area and the traversed material. The sparse module spacing in the endcap part of the stave allows for multiple fixation points, and for a stiff overall structure composed only of staves interconnected by stiff disks.

  10. X-ray Imaging Using a Hybrid Photon Counting GaAs Pixel Detector

    CERN Document Server

    Schwarz, C; Göppert, R; Heijne, Erik H M; Ludwig, J; Meddeler, G; Mikulec, B; Pernigotti, E; Rogalla, M; Runge, K; Smith, K M; Snoeys, W; Söldner-Rembold, S; Watt, J

    1999-01-01

    The performance of hybrid GaAs pixel detectors as X-ray imaging sensors were investigated at room temperature. These hybrids consist of 300 mu-m thick GaAs pixel detectors, flip-chip bonded to a CMOS Single Photon Counting Chip (PCC). This chip consists of a matrix of 64 x 64 identical square pixels (170 mu-m x 170 mu-m) and covers a total area of 1.2 cm**2. The electronics in each cell comprises a preamplifier, a discriminator with a 3-bit threshold adjust and a 15-bit counter. The detector is realized by an array of Schottky diodes processed on semi-insulating LEC-GaAs bulk material. An IV-charcteristic and a detector bias voltage scan showed that the detector can be operated with voltages around 200 V. Images of various objects were taken by using a standard X-ray tube for dental diagnostics. The signal to noise ratio (SNR) was also determined. The applications of these imaging systems range from medical applications like digital mammography or dental X-ray diagnostics to non destructive material testing (...

  11. Efficient defect pixel cluster detection and correction for Bayer CFA image sequences

    Science.gov (United States)

    Tajbakhsh, Touraj

    2011-01-01

    Image sensor arrays may have defect pixels, either originating from manufacturing or being developed over the lifetime of the image sensor array. Continuous defect pixel detection and correction performing during camera runtime is desirable. On-the-fly detection and correction is challenging since edges and high-frequency image content might get identified as defect pixel regions and intact pixels become corrupted during defect pixel replacement. We propose a table-based detection and correction method which by and by fills the non-volatile table during normal camera operation. In this work we model defect pixels and pixel clusters to be stuck to fixed values or at least fixed to a narrow value range whereas the local neighborhood of these pixels indicate a normal behavior. The idea is to temporally observe the value ranges of small group of pixels (e.g. 4x4 pixel blocks) and to decide about their defective condition depending on their variability with respect to their neighbor pixels. Our method is computationally efficient, requires no frame buffer, requires modest memory, and therefore is appropriate to operate in line-buffer based image signal processing (ISP) systems. Our results indicate high reliability in terms of detection rates and robustness against high-frequency image content. As part of the defect pixel replacement system we also propose a simple and efficient defect pixel correction method based on the mean of medians operating on the Bayer CFA image domain.

  12. DEPFET--a pixel device with integrated amplification

    CERN Document Server

    Neeser, W; Buchholz, P; Fischer, P; Holl, P; Kemmer, J; Klein, P; Koch, H; Löcker, M; Lutz, Gerhard; Matthäy, H; Strüder, L; Trimpl, M; Ulrici, J; Wermes, N

    2002-01-01

    In the DEPFET pixel concept, the absorbed radiation directly modulates the channel current of a p-JFET transistor being integrated into a fully depleted high ohmic silicon substrate in every pixel cell, offering very low noise operation at room temperature. Hence, DEPFET pixels open new possibilities in biomedical applications, but also have a potential in particle physics and astrophysics. Second prototype 50 mu mx50 mu m single pixels as well as large (64x64) DEPFET matrices have been successfully produced and operated confirming the low noise behavior (12e). Device studies as well as a full DEPFET pixel Bioscope system to be used in real-time digital autoradiography with excellent spatial and energy resolution for X-rays are presented.

  13. Development of a novel pixel-level signal processing chain for fast readout 3D integrated CMOS pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Y.; Torheim, O.; Hu-Guo, C. [Institut Pluridisciplinaire Hubert Curien (IPHC), 23 rue du loess, BP 28, 67037 Strasbourg (France); Degerli, Y. [CEA Saclay, IRFU/SEDI, 91191 Gif-sur-Yvette Cedex (France); Hu, Y., E-mail: yann.hu@iphc.cnrs.fr [Institut Pluridisciplinaire Hubert Curien (IPHC), 23 rue du loess, BP 28, 67037 Strasbourg (France)

    2013-03-11

    In order to resolve the inherent readout speed limitation of traditional 2D CMOS pixel sensors, operated in rolling shutter readout, a parallel readout architecture has been developed by taking advantage of 3D integration technologies. Since the rows of the pixel array are zero-suppressed simultaneously instead of sequentially, a frame readout time of a few microseconds is expected for coping with high hit rates foreseen in future collider experiments. In order to demonstrate the pixel readout functionality of such a pixel sensor, a 2D proof-of-concept chip including a novel pixel-level signal processing chain was designed and fabricated in a 0.13μm CMOS technology. The functionalities of this chip have been verified through experimental characterization.

  14. A Flash-ADC data acquisition system developed for a drift chamber array and a digital filter algorithm for signal processing

    Science.gov (United States)

    Yi, Han; Lü, Li-Ming; Zhang, Zhao; Cheng, Wen-Jing; Ji, Wei; Huang, Yan; Zhang, Yan; Li, Hong-Jie; Cui, Yin-Ping; Lin, Ming; Wang, Yi-Jie; Duan, Li-Min; Hu, Rong-Jiang; Xiao, Zhi-Gang

    2016-11-01

    A Flash-ADC data acquisition (DAQ) system has been developed for the drift chamber array designed for the External-Target-Experiment at the Cooling Storage Ring at the Heavy Ion Research Facility, Lanzhou. The simplified readout electronics system has been developed using the Flash-ADC modules and the whole waveform in the sampling window is obtained, with which the time and energy information can be deduced with an offline processing. A digital filter algorithm has been developed to discriminate the noise and the useful signal. With the digital filtering process, the signal to noise ratio (SNR) is increased and a better time and energy resolution can be obtained. Supported by National Basic Research Program of China (973) (2015CB856903 and 2014CB845405), partly by National Science Foundation of China (U1332207 and 11375094), and by Tsinghua University Initiative Scientific Research Program

  15. DigiCam - Fully Digital Compact Read-out and Trigger Electronics for the SST-1M Telescope proposed for the Cherenkov Telescope Array

    CERN Document Server

    Rajda, P; Bilnik, W.; Błocki, J.; Bogacz, L.; Bulik, T.; Cadoux, F.; Christov, A.; Curyło, M.; della Volpe, D.; Dyrda, M.; Favre, Y.; Frankowski, A.; Grudnik, Ł.; Grudzińska, M.; Heller, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandat, D.; Marszałek, A.; Michałowski, J.; Moderski, R.; Rameez, M.; Montaruli, T.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Paśko, P.; Pech, M.; Porcelli, A.; Prandini, E.; Schioppa, E. jr; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Pujadas, I. Troyano; Walter, R.; Więcek, M.; Zagdański, A.; Żychowski, P.

    2016-01-01

    The SST-1M is one of three prototype small-sized telescope designs proposed for the Cherenkov Telescope Array, and is built by a consortium of Polish and Swiss institutions. The SST-1M will operate with DigiCam - an innovative, compact camera with fully digital read-out and trigger electronics. A high level of integration will be achieved by massively deploying state-of-the-art multi-gigabit transmission channels, beginning from the ADC flash converters, through the internal data and trigger signals transmission over backplanes and cables, to the camera's server link. Such an approach makes it possible to design the camera to fit the size and weight requirements of the SST-1M exactly, and provide low power consumption, high reliability and long lifetime. The structure of the digital electronics will be presented, along with main physical building blocks and the internal architecture of FPGA functional subsystems.

  16. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: demonstrations with a passive wireless acoustic delay line probe and vision.

    Science.gov (United States)

    Goavec-Mérou, G; Chrétien, N; Friedt, J-M; Sandoz, P; Martin, G; Lenczner, M; Ballandras, S

    2014-01-01

    Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates.

  17. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  18. The Kepler Pixel Response Function

    CERN Document Server

    Bryson, Stephen T; Jenkins, Jon M; Chandrasekaran, Hema; Klaus, Todd; Caldwell, Douglas A; Gilliland, Ronald L; Haas, Michael R; Dotson, Jessie L; Koch, David G; Borucki, William J

    2010-01-01

    Kepler seeks to detect sequences of transits of Earth-size exoplanets orbiting Solar-like stars. Such transit signals are on the order of 100 ppm. The high photometric precision demanded by Kepler requires detailed knowledge of how the Kepler pixels respond to starlight during a nominal observation. This information is provided by the Kepler pixel response function (PRF), defined as the composite of Kepler's optical point spread function, integrated spacecraft pointing jitter during a nominal cadence and other systematic effects. To provide sub-pixel resolution, the PRF is represented as a piecewise-continuous polynomial on a sub-pixel mesh. This continuous representation allows the prediction of a star's flux value on any pixel given the star's pixel position. The advantages and difficulties of this polynomial representation are discussed, including characterization of spatial variation in the PRF and the smoothing of discontinuities between sub-pixel polynomial patches. On-orbit super-resolution measurement...

  19. ATLAS-IBL Pixel Upgrade

    CERN Document Server

    LaRosa, A; The ATLAS collaboration

    2010-01-01

    The upgrade for the ATLAS detector will undergo different phase towards Super-LHC. The first upgrade for the Pixel Detector will consist in the construction of a new pixel layer which will be installed during the first shutdown of the LHC machine (SLHC Phase I). The new detector, called Insertable B-Layer (IBL), will be inserted between the existing pixel detector and a new (smaller radius) beam-pipe at a radius of 3.2 cm. The IBL will require the development of several new technologies to cope with increase of radiation or pixel occupancy and also to improve the physics performance which will be achieved by reduction of the pixel size and of the material budget. Three different promising sensor technologies (Planar-Si, 3D-Si and Diamond) are currently under investigation for the pixel detector. An overview of the project with particular emphasis on pixel module studies, irradiation and beam test plans will be presented.

  20. Hybrid Pixel Detectors for gamma/X-ray imaging

    Science.gov (United States)

    Hatzistratis, D.; Theodoratos, G.; Zografos, V.; Kazas, I.; Loukas, D.; Lambropoulos, C. P.

    2015-09-01

    Hybrid pixel detectors are made by direct converting high-Z semi-insulating single crystalline material coupled to complementary-metal-oxide semiconductor (CMOS) readout electronics. They are attractive because direct conversion exterminates all the problems of spatial localization related to light diffusion, energy resolution, is far superior from the combination of scintillation crystals and photomultipliers and lithography can be used to pattern electrodes with very fine pitch. We are developing 2-D pixel CMOS ASICs, connect them to pixilated CdTe crystals with the flip chip and bump bonding method and characterize the hybrids. We have designed a series of circuits, whose latest member consists of a 50×25 pixel array with 400um pitch and an embedded controller. In every pixel a full spectroscopic channel with time tagging information has been implemented. The detectors are targeting Compton scatter imaging and they can be used for coded aperture imaging too. Hybridization using CMOS can overcome the limit put on pixel circuit complexity by the use of thin film transistors (TFT) in large flat panels. Hybrid active pixel sensors are used in dental imaging and other applications (e.g. industrial CT etc.). Thus X-ray imaging can benefit from the work done on dynamic range enhancement methods developed initially for visible and infrared CMOS pixel sensors. A 2-D CMOS ASIC with 100um pixel pitch to demonstrate the feasibility of such methods in the context of X-ray imaging has been designed.

  1. Pixel Stability in HST Advanced Camera for Surveys Images

    Science.gov (United States)

    Borncamp, David; Grogin, Norman A.; Bourque, Matthew; Ogaz, Sara

    2017-06-01

    Excess thermal energy present in a Charged Coupled Device (CCD) can result in additional electrical current that is propagated into individual pixels in an exposure. This excess signal from the CCD itself can be persistently existent through multiple exposures and can have an adverse effect on the detectors science performance unless properly flagged and corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed to map the location of these pixels. These images, generally referred to as “dark” images, allow for the measurement of the thermal-electron contamination present in each pixel of the CCD lattice. This "dark current" can then be subtracted from the science images by re-scaling the dark to the science exposure times. Pixels that have signal above a certain threshold are traditionally marked as “hot” and flagged in the data quality array. Many users will discard these pixels as being bad because of this extra current. However, these pixels may not be "bad" in the traditional sense that they cannot be reliably dark-subtracted. If these pixels are shown to be stable over an anneal period, the charge can be properly subtracted and the extra Poisson noise from this hot pixel’s dark current can be taken into account. Here we present the results of a pixel history study that analyzes every individual pixel of the Hubble Space Telescope's (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs over time and allows pixels that were previously marked as bad to be brought back into the science image as a reliable pixel.

  2. Fabrication and Test of Pixelated CZT Detectors with Different Pixel Pitches and Thicknesses

    OpenAIRE

    Li, Q.; Garson, A.; Dowkontt, P.; Martin, J.; Beilicke, M; Jung, I.; Groza, M.; A. Burger; De Geronimo, G.; Krawczynski, H.; .

    2008-01-01

    The main methods grown Cadmium Zinc Telluride (CZT) crystals with high yield and excellent homogeneity are Modified Horizontal Bridgman (MHB) and High Pressure Bridgman (HPB) processes, respectively. In this contribution, the readout system based on two 32-channel NCI-ASICs for pixellated CZT detector arrays has been developed and tested. The CZT detectors supplied by Orbotech (MHB) and eV products (HPB) are tested by NCI-ASIC readout system. The CZT detectors have an array of 8x8 or 11x11 pi...

  3. Modelling semiconductor pixel detectors

    CERN Document Server

    Mathieson, K

    2001-01-01

    expected after 200 ps in most cases. The effect of reducing the charge carrier lifetime and examining the charge collection efficiency has been utilised to explore how these detectors would respond in a harsh radiation environment. It is predicted that over critical carrier lifetimes (10 ps to 0.1 ns) an improvement of 40 % over conventional detectors can be expected. This also has positive implications for fabricating detectors, in this geometry, from materials which might otherwise be considered substandard. An analysis of charge transport in CdZnTe pixel detectors has been performed. The analysis starts with simulation studies into the formation of contacts and their influence on the internal electric field of planar detectors. The models include a number of well known defect states and these are balanced to give an agreement with a typical experimental I-V curve. The charge transport study extends to the development of a method for studying the effect of charge sharing in highly pixellated detectors. The ...

  4. The ALICE pixel detector

    CERN Document Server

    Mercado Perez, J

    2002-01-01

    The present document is a brief summary of the performed activities during the 2001 Summer Student Programme at CERN under the Scientific Summer at Foreign Laboratories Program organized by the Particles and Fields Division of the Mexican Physical Society (Sociedad Mexicana de Fisica). In this case, the activities were related with the ALICE Pixel Group of the EP-AIT Division, under the supervision of Jeroen van Hunen, research fellow in this group. First, I give an introduction and overview to the ALICE experiment; followed by a description of wafer probing. A brief summary of the test beam that we had from July 13th to July 25th is given as well. (3 refs).

  5. Pixelated gamma detector

    Energy Technology Data Exchange (ETDEWEB)

    Dolinsky, Sergei Ivanovich; Yanoff, Brian David; Guida, Renato; Ivan, Adrian

    2016-12-27

    A pixelated gamma detector includes a scintillator column assembly having scintillator crystals and optical transparent elements alternating along a longitudinal axis, a collimator assembly having longitudinal walls separated by collimator septum, the collimator septum spaced apart to form collimator channels, the scintillator column assembly positioned adjacent to the collimator assembly so that the respective ones of the scintillator crystal are positioned adjacent to respective ones of the collimator channels, the respective ones of the optical transparent element are positioned adjacent to respective ones of the collimator septum, and a first photosensor and a second photosensor, the first and the second photosensor each connected to an opposing end of the scintillator column assembly. A system and a method for inspecting and/or detecting defects in an interior of an object are also disclosed.

  6. Modeling Inter-Pixel Crosstalk in Teledyne Imaging Sensors H4RG Detectors

    CERN Document Server

    Dudik, R P; Dorland, B N; Veillette, D; Waczynski, A; Lane, B; Loose, M; Kan, E; Waterman, J; Pravdo, S

    2012-01-01

    CMOS-hybrid arrays have recently surfaced as competitive optical detectors for use in ground- and space-based astronomy. One source of error in these detectors that does not appear in more traditional CCD arrays is the inter-pixel capacitance component of crosstalk. In this paper we use a single pixel reset method to model inter-pixel capacitance (IPC). We combine this IPC model with a model for charge diffusion to estimate the total crosstalk on H4RG arrays. Finally, we compare our model results to Fe55 data obtained using an astrometric camera built to test the H4RG-B0 generation detectors.

  7. Planar Pixelations and Image Recognition

    CERN Document Server

    Rowekamp, Brandon

    2011-01-01

    Any subset of the plane can be approximated by a set of square pixels. This transition from a shape to its pixelation is rather brutal since it destroys geometric and topological information about the shape. Using a technique inspired by Morse Theory, we algorithmically produce a PL approximation of the original shape using only information from its pixelation. This approximation converges to the original shape in a very strong sense: as the size of the pixels goes to zero we can recover important geometric and topological invariants of the original shape such as Betti numbers, area, perimeter and curvature measures.

  8. Digital selective growth of a ZnO nanowire array by large scale laser decomposition of zinc acetate

    Science.gov (United States)

    Hong, Sukjoon; Yeo, Junyeob; Manorotkul, Wanit; Kang, Hyun Wook; Lee, Jinhwan; Han, Seungyong; Rho, Yoonsoo; Suh, Young Duk; Sung, Hyung Jin; Ko, Seung Hwan

    2013-04-01

    We develop a digital direct writing method for ZnO NW micro-patterned growth on a large scale by selective laser decomposition of zinc acetate. For ZnO NW growth, by replacing the bulk heating with the scanning focused laser as a fully digital local heat source, zinc acetate crystallites can be selectively activated as a ZnO seed pattern to grow ZnO nanowires locally on a larger area. Together with the selective laser sintering process of metal nanoparticles, more than 10 000 UV sensors have been demonstrated on a 4 cm × 4 cm glass substrate to develop all-solution processible, all-laser mask-less digital fabrication of electronic devices including active layer and metal electrodes without any conventional vacuum deposition, photolithographic process, premade mask, high temperature and vacuum environment.We develop a digital direct writing method for ZnO NW micro-patterned growth on a large scale by selective laser decomposition of zinc acetate. For ZnO NW growth, by replacing the bulk heating with the scanning focused laser as a fully digital local heat source, zinc acetate crystallites can be selectively activated as a ZnO seed pattern to grow ZnO nanowires locally on a larger area. Together with the selective laser sintering process of metal nanoparticles, more than 10 000 UV sensors have been demonstrated on a 4 cm × 4 cm glass substrate to develop all-solution processible, all-laser mask-less digital fabrication of electronic devices including active layer and metal electrodes without any conventional vacuum deposition, photolithographic process, premade mask, high temperature and vacuum environment. Electronic supplementary information available. See DOI: 10.1039/c3nr34346d

  9. Photovoltaic retinal prosthesis with high pixel density

    Science.gov (United States)

    Mathieson, Keith; Loudin, James; Goetz, Georges; Huie, Philip; Wang, Lele; Kamins, Theodore I.; Galambos, Ludwig; Smith, Richard; Harris, James S.; Sher, Alexander; Palanker, Daniel

    2012-06-01

    Retinal degenerative diseases lead to blindness due to loss of the `image capturing' photoreceptors, while neurons in the `image-processing' inner retinal layers are relatively well preserved. Electronic retinal prostheses seek to restore sight by electrically stimulating the surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems that deliver energy to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel receive power and data directly through pulsed near-infrared illumination and electrically stimulate neurons. Stimulation is produced in normal and degenerate rat retinas, with pulse durations of 0.5-4 ms, and threshold peak irradiances of 0.2-10 mW mm-2, two orders of magnitude below the ocular safety limit. Neural responses were elicited by illuminating a single 70 µm bipolar pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high pixel density.

  10. Readout Architecture for Hybrid Pixel Readout Chips

    CERN Document Server

    AUTHOR|(SzGeCERN)694170; Westerlund, Tomi; Wyllie, Ken

    The original contribution of this thesis to knowledge are novel digital readout architectures for hybrid pixel readout chips. The thesis presents asynchronous bus-based architecture, a data-node based column architecture and a network-based pixel matrix architecture for data transportation. It is shown that the data-node architecture achieves readout efficiency 99 % with half the output rate as a bus-based system. The network-based solution avoids ``broken'' columns due to some manufacturing errors, and it distributes internal data traffic more evenly across the pixel matrix than column-based architectures. An improvement of $>$ 10 % to the efficiency is achieved with uniform and non-uniform hit occupancies. Architectural design has been done using transaction level modeling ($TLM$) and sequential high-level design techniques for reducing the design and simulation time. It has been possible to simulate tens of column and full chip architectures using the high-level techniques. A decrease of $>$ 10 in run-time...

  11. Using a pulsed laser beam to investigate the feasibility of sub-pixel position resolution with time-correlated transient signals in 3D pixelated CdZnTe detectors

    Science.gov (United States)

    Giraldo, L. Ocampo; Bolotnikov, A. E.; Camarda, G. S.; Cheng, S.; De Geronimo, G.; McGilloway, A.; Fried, J.; Hodges, D.; Hossain, A.; Ünlü, K.; Petryk, M.; Vidal, V.; Vernon, E.; Yang, G.; James, R. B.

    2017-09-01

    We evaluated the X-Y position resolution achievable in 3D pixelated detectors by processing the signal waveforms readout from neighboring pixels. In these measurements we used a focused light beam, down to 10 μm, generated by a 1 mW pulsed laser (650 nm) to carry out raster scans over selected 3×3 pixel areas, while recording the charge signals from the 9 pixels and the cathode using two synchronized digital oscilloscopes.

  12. Deep-turbulence wavefront sensing using digital-holographic detection in the off-axis image plane recording geometry

    Science.gov (United States)

    Spencer, Mark F.; Raynor, Robert A.; Banet, Matthias T.; Marker, Dan K.

    2017-03-01

    This paper develops wave-optics simulations which explore the estimation accuracy of digital-holographic detection for wavefront sensing in the presence of distributed-volume or "deep" turbulence and detection noise. Specifically, the analysis models spherical-wave propagation through varying deep-turbulence conditions along a horizontal propagation path and formulates the field-estimated Strehl ratio as a function of the diffraction-limited sampling quotient and signal-to-noise ratio. Such results will allow the reader to assess the number of pixels, pixel field of view, pixel-well depth, and read-noise standard deviation needed from a focal-plane array when using digital-holographic detection in the off-axis image plane recording geometry for deep-turbulence wavefront sensing.

  13. CryoPAF4: a cryogenic phased array feed design

    Science.gov (United States)

    Locke, Lisa; Garcia, Dominic; Halman, Mark; Henke, Doug; Hovey, Gary; Jiang, Nianhua; Knee, Lewis; Lacy, Gordon; Loop, David; Rupen, Michael; Veidt, Bruce; Wierzbicki, Ramunas

    2016-07-01

    Phased array feed (PAF) receivers used on radio astronomy telescopes offer the promise of increased fields of view while maintaining the superlative performance attained with traditional single pixel feeds (SPFs). However, the much higher noise temperatures of room temperature PAFs compared to cryogenically-cooled SPFs have prevented their general adoption. Here we describe a conceptual design for a cryogenically cooled 2.8 - 5.18 GHz dual linear polarization PAF with estimated receiver temperature of 11 K. The cryogenic PAF receiver will comprise a 140 element Vivaldi antenna array and low-noise amplifiers housed in a 480 mm diameter cylindrical dewar covered with a RF transparent radome. A broadband two-section coaxial feed is integrated within each metal antenna element to withstand the cryogenic environment and to provide a 50 ohm impedance for connection to the rest of the receiver. The planned digital beamformer performs digitization, frequency band selection, beam forming and array covariance matrix calibration. Coupling to a 15 m offset Gregorian dual-reflector telescope, cryoPAF4 can expect to form 18 overlapping beams increasing the field of view by a factor of 8x compared to a single pixel receiver of equal system temperature.

  14. MTF study of planar small pixel pitch quantum IR detectors

    Science.gov (United States)

    Gravrand, O.; Baier, N.; Ferron, A.; Rochette, F.; Berthoz, J.; Rubaldo, L.; Cluzel, R.

    2014-06-01

    The actual trend in quantum IR detector development is the design of very small pixel pitch large arrays. From previously 30μm pitch, the standard pixel pitch is today 15μm and is expected to decrease to 12μm in the next few years. Furthermore, focal plane arrays (FPA) with pixel pitch as small as small as 10μm has been demonstrated. Such ultra-small pixel pitches are very small compared to the typical length ruling the electrical characteristics of the absorbing materials, namely the minority carrier diffusion length. As an example for low doped N type HgCdTe or InSb material, this diffusion length is of the order of 30 to 50μm, i.e. 3 to 5 times the targeted pixel pitches. This has strong consequences on the modulation transfer function (MTF) for planar structures, where the lateral extension of the photodiode is limited by diffusion. For such aspect ratios, the self-confinement of neighboring diodes may not be efficient enough to maintain optimal MTF. Therefore, this issue has to be addressed in order to take full benefits of the pixel pitch reduction in terms of image resolution. This paper aims at investigating the MTF evolution of HgCdTe and InSb FPAs decreasing the pixel pitch below 15μm. Both experimental measurements and finite element simulations are used to discuss this issue. Different scenarii will be compared, namely deep mesa etch between pixels, internal drift, surface recombination, thin absorbing layers.

  15. Pixel History for Advanced Camera for Surveys Wide Field Channel

    Science.gov (United States)

    Borncamp, D.; Grogin, N.; Bourque, M.; Ogaz, S.

    2017-06-01

    Excess thermal energy present in a Charged Coupled Device (CCD) can result in additional electrical current. This excess charge is trapped within the silicon lattice structure of the CCD electronics. It can persist through multiple exposures and have an adverse effect on science performance of the detectors unless properly flagged and corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as "dark" images, allow for the measurement of the thermal-electron contamination present in each pixel of the CCD lattice. This so-called "dark current" can then be subtracted from the science images by re-scaling the dark to the corresponding exposure times. Pixels that have signal above a certain threshold are traditionally marked as "hot" and flagged in the data quality array. Many users will discard these because of the extra current. However, these pixels may not be unusable because of an unreliable dark subtraction; if we find these pixels to be stable over an anneal period, we can properly subtract the charge and the extra Poisson noise from this dark current will be propagated into the error arrays. Here we present the results of a pixel history study that analyzes every individual pixel of the Hubble Space Telescope's (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs over time and allows pixels that were previously flagged as unusable to be brought back into the science image as a reliable pixel.

  16. Small pixel CZT detector for hard X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Matthew David, E-mail: Matt.Wilson@stfc.ac.uk [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX (United Kingdom); Cernik, Robert [Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester (United Kingdom); Chen, Henry [Redlen Technologies, Saanichton, British Columbia (Canada); Hansson, Conny [Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester (United Kingdom); Iniewski, Kris [Redlen Technologies, Saanichton, British Columbia (Canada); Jones, Lawrence L.; Seller, Paul; Veale, Matthew C. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxfordshire OX11 0QX (United Kingdom)

    2011-10-01

    A new small pixel cadmium zinc telluride (CZT) detector has been developed for hard X-ray spectroscopy. The X-ray performance of four detectors is presented and the detectors are analysed in terms of the energy resolution of each pixel. The detectors were made from CZT crystals grown by the travelling heater method (THM) bonded to a 20x20 application specific integrated circuit (ASIC) and data acquisition (DAQ) system. The detectors had an array of 20x20 pixels on a 250 {mu}m pitch, with each pixel gold-stud bonded to an energy resolving circuit in the ASIC. The DAQ system digitised the ASIC output with 14 bit resolution, performing offset corrections and data storage to disc in real time at up to 40,000 frames per second. The detector geometry and ASIC design was optimised for X-ray spectroscopy up to 150 keV and made use of the small pixel effect to preferentially measure the electron signal. A {sup 241}Am source was used to measure the spectroscopic performance and uniformity of the detectors. The average energy resolution (FWHM at 59.54 keV) of each pixel ranged from 1.09{+-}0.46 to 1.50{+-}0.57 keV across the four detectors. The detectors showed good spectral performance and uniform response over almost all pixels in the 20x20 array. A large area 80x80 pixel detector will be built that will utilise the scalable design of the ASIC and the large areas of monolithic spectroscopic grade THM grown CZT that are now available. The large area detector will have the same performance as that demonstrated here.

  17. Small pixel CZT detector for hard X-ray spectroscopy

    Science.gov (United States)

    Wilson, Matthew David; Cernik, Robert; Chen, Henry; Hansson, Conny; Iniewski, Kris; Jones, Lawrence L.; Seller, Paul; Veale, Matthew C.

    2011-10-01

    A new small pixel cadmium zinc telluride (CZT) detector has been developed for hard X-ray spectroscopy. The X-ray performance of four detectors is presented and the detectors are analysed in terms of the energy resolution of each pixel. The detectors were made from CZT crystals grown by the travelling heater method (THM) bonded to a 20×20 application specific integrated circuit (ASIC) and data acquisition (DAQ) system. The detectors had an array of 20×20 pixels on a 250 μm pitch, with each pixel gold-stud bonded to an energy resolving circuit in the ASIC. The DAQ system digitised the ASIC output with 14 bit resolution, performing offset corrections and data storage to disc in real time at up to 40,000 frames per second. The detector geometry and ASIC design was optimised for X-ray spectroscopy up to 150 keV and made use of the small pixel effect to preferentially measure the electron signal. A 241Am source was used to measure the spectroscopic performance and uniformity of the detectors. The average energy resolution (FWHM at 59.54 keV) of each pixel ranged from 1.09±0.46 to 1.50±0.57 keV across the four detectors. The detectors showed good spectral performance and uniform response over almost all pixels in the 20×20 array. A large area 80×80 pixel detector will be built that will utilise the scalable design of the ASIC and the large areas of monolithic spectroscopic grade THM grown CZT that are now available. The large area detector will have the same performance as that demonstrated here.

  18. A germanium hybrid pixel detector with 55μm pixel size and 65,000 channels

    Science.gov (United States)

    Pennicard, D.; Struth, B.; Hirsemann, H.; Sarajlic, M.; Smoljanin, S.; Zuvic, M.; Lampert, M. O.; Fritzsch, T.; Rothermund, M.; Graafsma, H.

    2014-12-01

    Hybrid pixel semiconductor detectors provide high performance through a combination of direct detection, a relatively small pixel size, fast readout and sophisticated signal processing circuitry in each pixel. For X-ray detection above 20 keV, high-Z sensor layers rather than silicon are needed to achieve high quantum efficiency, but many high-Z materials such as GaAs and CdTe often suffer from poor material properties or nonuniformities. Germanium is available in large wafers of extremely high quality, making it an appealing option for high-performance hybrid pixel X-ray detectors, but suitable technologies for finely pixelating and bump-bonding germanium have not previously been available. A finely-pixelated germanium photodiode sensor with a 256 by 256 array of 55μm pixels has been produced. The sensor has an n-on-p structure, with 700μm thickness. Using a low-temperature indium bump process, this sensor has been bonded to the Medipix3RX photoncounting readout chip. Tests with the LAMBDA readout system have shown that the detector works successfully, with a high bond yield and higher image uniformity than comparable high-Z systems. During cooling, the system is functional around -80°C (with warmer temperatures resulting in excessive leakage current), with -100°C sufficient for good performance.

  19. Diamond pixel modules

    CERN Document Server

    Gan, K K; Robichaud, A; Potenza, R; Kuleshov, S; Kagan, H; Kass, R; Wermes, N; Dulinski, W; Eremin, V; Smith, S; Sopko, B; Olivero, P; Gorisek, A; Chren, D; Kramberger, G; Schnetzer, S; Weilhammer, P; Martemyanov, A; Hugging, F; Pernegger, H; Lagomarsino, S; Manfredotti, C; Mishina, M; Trischuk, W; Dobos, D; Cindro, V; Belyaev, V; Duris, J; Claus, G; Wallny, R; Furgeri, A; Tuve, C; Goldstein, J; Sciortino, S; Sutera, C; Asner, D; Mikuz, M; Lo Giudice, A; Velthuis, J; Hits, D; Griesmayer, E; Oakham, G; Frais-Kolbl, H; Bellini, V; D'Alessandro, R; Cristinziani, M; Barbero, M; Schaffner, D; Costa, S; Goffe, M; La Rosa, A; Bruzzi, M; Schreiner, T; de Boer, W; Parrini, G; Roe, S; Randrianarivony, K; Dolenc, I; Moss, J; Brom, J M; Golubev, A; Mathes, M; Eusebi, R; Grigoriev, E; Tsung, J W; Mueller, S; Mandic, I; Stone, R; Menichelli, D

    2011-01-01

    With the commissioning of the LHC in 2010 and upgrades expected in 2015, ATLAS and CMS are planning to upgrade their innermost tracking layers with radiation hard technologies. Chemical Vapor Deposition diamond has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. This material is now being considered as a sensor material for use very close to the interaction region where the most extreme radiation conditions exist Recently the RD42 collaboration constructed, irradiated and tested polycrystalline and single-crystal chemical vapor deposition diamond sensors to the highest fluences expected at the super-LHC. We present beam test results of chemical vapor deposition diamond up to fluences of 1.8 x 10(16) protons/cm(2) illustrating that both polycrystalline and single-crystal chemical vapor deposition diamonds follow a single damage curve. We also present beam test results of irradiated complete diamond pixel m...

  20. An integrating CMOS APS for X-ray imaging with an in-pixel preamplifier

    Science.gov (United States)

    Abdalla, M. A.; Fröjdh, C.; Petersson, C. S.

    2001-06-01

    We present in this paper an integrating CMOS Active Pixel Sensor (APS) circuit coated with scintillator type sensors for intra-oral dental X-ray imaging systems. The photosensing element in the pixel is formed by the p-diffusion on the n-well diode. The advantage of this photosensor is its very low direct absorption of X-rays compared to the other available photosensing elements in the CMOS pixel. The pixel features an integrating capacitor in the feedback loop of a preamplifier of a finite gain in order to increase the optical sensitivity. To verify the effectiveness of this in-pixel preamplification, a prototype 32×80 element CMOS active pixel array was implemented in a 0.8 μm CMOS double poly, n-well process with a pixel pitch of 50 μm. Measured results confirmed the improved optical sensitivity performance of the APS. Various measurements on device performance are presented.

  1. CMOS VLSI Active-Pixel Sensor for Tracking

    Science.gov (United States)

    Pain, Bedabrata; Sun, Chao; Yang, Guang; Heynssens, Julie

    2004-01-01

    An architecture for a proposed active-pixel sensor (APS) and a design to implement the architecture in a complementary metal oxide semiconductor (CMOS) very-large-scale integrated (VLSI) circuit provide for some advanced features that are expected to be especially desirable for tracking pointlike features of stars. The architecture would also make this APS suitable for robotic- vision and general pointing and tracking applications. CMOS imagers in general are well suited for pointing and tracking because they can be configured for random access to selected pixels and to provide readout from windows of interest within their fields of view. However, until now, the architectures of CMOS imagers have not supported multiwindow operation or low-noise data collection. Moreover, smearing and motion artifacts in collected images have made prior CMOS imagers unsuitable for tracking applications. The proposed CMOS imager (see figure) would include an array of 1,024 by 1,024 pixels containing high-performance photodiode-based APS circuitry. The pixel pitch would be 9 m. The operations of the pixel circuits would be sequenced and otherwise controlled by an on-chip timing and control block, which would enable the collection of image data, during a single frame period, from either the full frame (that is, all 1,024 1,024 pixels) or from within as many as 8 different arbitrarily placed windows as large as 8 by 8 pixels each. A typical prior CMOS APS operates in a row-at-a-time ( grolling-shutter h) readout mode, which gives rise to exposure skew. In contrast, the proposed APS would operate in a sample-first/readlater mode, suppressing rolling-shutter effects. In this mode, the analog readout signals from the pixels corresponding to the windows of the interest (which windows, in the star-tracking application, would presumably contain guide stars) would be sampled rapidly by routing them through a programmable diagonal switch array to an on-chip parallel analog memory array. The

  2. Stimulation with a low-amplitude, digitized synaptic signal to invoke robust activity within neuronal networks on multielectrode arrays.

    Science.gov (United States)

    Zemianek, Jill M; Serra, Michael; Guaraldi, Mary; Shea, Thomas B

    2012-03-01

    Multielectrode arrays (MEAs) are used for analysis of neuronal activity. Here we report two variations on commonly accepted techniques that increase the precision of extracellular electrical stimulation: (i) the use of a low-amplitude recorded spontaneous synaptic signal as a stimulus waveform and (ii) the use of a specific electrode within the array adjacent to the stimulus electrode as a hard-grounded stimulus signal return path. Both modifications remained compatible with manipulation of neuronal networks. In addition, localized stimulation with the low-amplitude synaptic signal allowed selective stimulation or inhibition of otherwise spontaneous signals. These findings indicate that minimizing the area of the culture impacted by external stimulation allows modulation of signaling patterns within subpopulations of neurons in culture. The simple modifications described herein may be useful for precise monitoring and manipulation of neuronal networks.

  3. Rhodopsin in plasma from patients with diabetic retinopathy - development and validation of digital ELISA by Single Molecule Array (Simoa) technology

    DEFF Research Database (Denmark)

    Petersen, Eva Rabing Brix; Olsen, Dorte Aalund; Christensen, Henry

    2017-01-01

    BACKGROUND: Diabetic retinopathy (DR) is the most frequent cause of blindness among younger adults in the western world. No blood biomarkers exist to detect DR. Hypothetically, Rhodopsin concentrations in blood has been suggested as an early marker for retinal damage. The aim of this study...... was therefore to develop and validate a Rhodopsin assay by employing digital ELISA technology, and to investigate whether Rhodopsin concentrations in diabetes patients with DR are elevated compared with diabetes patients without DR. METHODS: A digital ELISA assay using a Simoa HD-1 Analyzer (Quanterix......©, Lexington, MA 02421, USA) was developed and validated and applied on a cohort of diabetes patients characterised with (n=466) and without (n=144) DR. RESULTS: The Rhodopsin assay demonstrated a LOD of 0.26ng/l, a LLOQ of 3ng/l and a linear measuring range from 3 to 2500ng/l. Total CV% was 32%, 23%, 19...

  4. From Pixels to Planets

    Science.gov (United States)

    Brownston, Lee; Jenkins, Jon M.

    2015-01-01

    The Kepler Mission was launched in 2009 as NASAs first mission capable of finding Earth-size planets in the habitable zone of Sun-like stars. Its telescope consists of a 1.5-m primary mirror and a 0.95-m aperture. The 42 charge-coupled devices in its focal plane are read out every half hour, compressed, and then downlinked monthly. After four years, the second of four reaction wheels failed, ending the original mission. Back on earth, the Science Operations Center developed the Science Pipeline to analyze about 200,000 target stars in Keplers field of view, looking for evidence of periodic dimming suggesting that one or more planets had crossed the face of its host star. The Pipeline comprises several steps, from pixel-level calibration, through noise and artifact removal, to detection of transit-like signals and the construction of a suite of diagnostic tests to guard against false positives. The Kepler Science Pipeline consists of a pipeline infrastructure written in the Java programming language, which marshals data input to and output from MATLAB applications that are executed as external processes. The pipeline modules, which underwent continuous development and refinement even after data started arriving, employ several analytic techniques, many developed for the Kepler Project. Because of the large number of targets, the large amount of data per target and the complexity of the pipeline algorithms, the processing demands are daunting. Some pipeline modules require days to weeks to process all of their targets, even when run on NASA's 128-node Pleiades supercomputer. The software developers are still seeking ways to increase the throughput. To date, the Kepler project has discovered more than 4000 planetary candidates, of which more than 1000 have been independently confirmed or validated to be exoplanets. Funding for this mission is provided by NASAs Science Mission Directorate.

  5. Wideband digitally tunable lasers based on fiber Bragg grating external cavity array and 1×N optical switch

    Institute of Scientific and Technical Information of China (English)

    Haiwen Cai(蔡海文); Jianxin Geng(耿建新); Zuoren Dong(董作人); Gaoting Chen(陈高庭); Zujie Fang(方祖捷)

    2003-01-01

    A novel wideband digitally tunable laser based on fiber Bragg grating external cavities and 1 × N optical switch provides 5 ms fast tuning time with output power more than 1 dBm over whole C-band that is only limited by the laser emission bandwidth. Less than 50 pm wavelength drift over -10 to 55℃ temperature range make that the wavelength locker and monitor are not necessary in this tunable laser.

  6. Investigating the effect of pixel size of high spatial resolution FTIR imaging for detection of colorectal cancer

    Science.gov (United States)

    Lloyd, G. R.; Nallala, J.; Stone, N.

    2016-03-01

    FTIR is a well-established technique and there is significant interest in applying this technique to medical diagnostics e.g. to detect cancer. The introduction of focal plane array (FPA) detectors means that FTIR is particularly suited to rapid imaging of biopsy sections as an adjunct to digital pathology. Until recently however each pixel in the image has been limited to a minimum of 5.5 µm which results in a comparatively low magnification image or histology applications and potentially the loss of important diagnostic information. The recent introduction of higher magnification optics gives image pixels that cover approx. 1.1 µm. This reduction in image pixel size gives images of higher magnification and improved spatial detail can be observed. However, the effect of increasing the magnification on spectral quality and the ability to discriminate between disease states is not well studied. In this work we test the discriminatory performance of FTIR imaging using both standard (5.5 µm) and high (1.1 µm) magnification for the detection of colorectal cancer and explore the effect of binning to degrade high resolution images to determine whether similar diagnostic information and performance can be obtained using both magnifications. Results indicate that diagnostic performance using high magnification may be reduced as compared to standard magnification when using existing multivariate approaches. Reduction of the high magnification data to standard magnification via binning can potentially recover some of the lost performance.

  7. Multiport solid-state imager characterization at variable pixel rates

    Energy Technology Data Exchange (ETDEWEB)

    Yates, G.J.; Albright, K.A. [Los Alamos National Lab., NM (United States); Turko, B.T. [Lawrence Berkeley Lab., CA (United States)

    1993-08-01

    The imaging performance of an 8-port Full Frame Transfer Charge Coupled Device (FFT CCD) as a function of several parameters including pixel clock rate is presented. The device, model CCD- 13, manufactured by English Electric Valve (EEV) is a 512 {times} 512 pixel array designed with four individual programmable bidirectional serial registers and eight output amplifiers permitting simultaneous readout of eight segments (128 horizontal {times} 256 vertical pixels) of the array. The imager was evaluated in Los Alamos National Laboratory`s High-Speed Solid-State Imager Test Station at true pixel rates as high as 50 MHz for effective imager pixel rates approaching 400 MHz from multiporting. Key response characteristics measured include absolute responsivity, Charge-Transfer-Efficiency (CTE), dynamic range, resolution, signal-to-noise ratio, and electronic and optical crosstalk among the eight video channels. Preliminary test results and data obtained from the CCD-13 will be presented and the versatility/capabilities of the test station will be reviewed.

  8. Coincidence detection of spatially correlated photon pairs with a monolithic time-resolving detector array

    CERN Document Server

    Unternährer, Manuel; Gasparini, Leonardo; Stoppa, David; Stefanov, André

    2016-01-01

    We demonstrate coincidence measurements of spatially entangled photons by means of a novel type of multi-pixel based detection array. The adopted sensor is a fully digital 8$\\times$16 silicon photomultiplier array allowing not only photon counting but also per-pixel time stamping of the arrived photons with a resolution of 65 ps. Together with a frame rate of 500 kfps, this property exceeds the capabilities of conventional charge-coupled device cameras which have become of growing interest for the detection of transversely correlated photon pairs. The sensor is used to measure a second-order correlation function for various non-collinear configurations of entangled photons generated by spontaneous parametric down-conversion. The experimental results are compared to theory.

  9. Digitizing radiographic films: a simple way to evaluate indirect digital images

    Directory of Open Access Journals (Sweden)

    Izabel Regina Fischer Rubia-Bullen

    2007-02-01

    Full Text Available OBJECTIVES: This study applied a simple method to evaluate the performance of three digital devices (two scanners and one digital camera using the reproducibility of pixel values attributed to the same radiographic image. METHODS: Using the same capture parameters, a radiographic image was repeatedly digitized in order to determine the variability of pixel values given to the image throughout the digitization process. One coefficient value was obtained and was called pixel value reproducibility. RESULTS: A significant difference in pixel values was observed among the three devices for the digitized images (ANOVA, p<0.00001. There was significant pixel value variability at the same digitization conditions for one scanner and the digital camera. CONCLUSIONS: Digital devices may assign pixel values differently in consecutive digitization depending on the optical density of the radiographic image and the equipment. The pixel value reproducibility was not satisfactory as tested for two devices. It is maybe advisable knowing the digitization variations regarding pixel values whenever using digital radiography images in longitudinal clinical examinations.

  10. SMN1 and SMN2 copy numbers in cell lines derived from patients with spinal muscular atrophy as measured by array digital PCR.

    Science.gov (United States)

    Stabley, Deborah L; Harris, Ashlee W; Holbrook, Jennifer; Chubbs, Nicholas J; Lozo, Kevin W; Crawford, Thomas O; Swoboda, Kathryn J; Funanage, Vicky L; Wang, Wenlan; Mackenzie, William; Scavina, Mena; Sol-Church, Katia; Butchbach, Matthew E R

    2015-07-01

    Proximal spinal muscular atrophy (SMA) is an early-onset motor neuron disease characterized by loss of α-motor neurons and associated muscle atrophy. SMA is caused by deletion or other disabling mutation of survival motor neuron 1 (SMN1). In the human genome, a large duplication of the SMN-containing region gives rise to a second copy of this gene (SMN2) that is distinguishable by a single nucleotide change in exon 7. Within the SMA population, there is substantial variation in SMN2 copy number; in general, those individuals with SMA who have a high SMN2 copy number have a milder disease. Because SMN2 functions as a disease modifier, its accurate copy number determination may have clinical relevance. In this study, we describe the development of an assay to assess SMN1 and SMN2 copy numbers in DNA samples using an array-based digital PCR (dPCR) system. This dPCR assay can accurately and reliably measure the number of SMN1 and SMN2 copies in DNA samples. In a cohort of SMA patient-derived cell lines, the assay confirmed a strong inverse correlation between SMN2 copy number and disease severity. Array dPCR is a practical technique to determine, accurately and reliably, SMN1 and SMN2 copy numbers from SMA samples.

  11. Monolithic single-photon detectors and time-to-digital converters for picoseconds time-of-flight ranging

    Science.gov (United States)

    Markovic, Bojan; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2011-03-01

    We present a novel "smart-pixel" able to measure and record in-pixel the time delay (photon timing) between a START (e.g. given by laser excitation, cell stimulus, or LIDAR flash) and a STOP (e.g. arrival of the first returning photon from the fluorescence decay signal or back reflection from an object). Such smart-pixel relies of a SPAD detector and a Timeto- Digital Converter monolithically designed and manufactured in the same chip. Many pixels can be laid out in a rows by columns architecture, to give birth to expandable 2D imaging arrays for picoseconds-level single-photon timing applications. Distance measurements, by means of direct TOF detection (used in LIDAR systems) provided by each pixel, can open the way to the fabrication of single-chip 3D ranging arrays for scene reconstruction and intelligent object recognition. We report on the design and characterization of prototype circuits, fabricated in a 0.35 μm standard CMOS technology containing complete conversion channels, "smart-pixel" and ancillary electronics with 20 μm active area diameter SPAD detector and related quenching circuitry. With a 100 MHz reference clock, the TDC provides timeresolution of 10 ps, dynamic range of 160 ns and very high conversion linearity.

  12. CMS Barrel Pixel Detector Overview

    CERN Document Server

    Kästli, H C; Erdmann, W; Gabathuler, K; Hörmann, C; Horisberger, Roland Paul; König, S; Kotlinski, D; Meier, B; Robmann, P; Rohe, T; Streuli, S

    2007-01-01

    The pixel detector is the innermost tracking device of the CMS experiment at the LHC. It is built from two independent sub devices, the pixel barrel and the end disks. The barrel consists of three concentric layers around the beam pipe with mean radii of 4.4, 7.3 and 10.2 cm. There are two end disks on each side of the interaction point at 34.5 cm and 46.5 cm. This article gives an overview of the pixel barrel detector, its mechanical support structure, electronics components, services and its expected performance.

  13. Pixel readout ASIC for an APD based 2D X-ray hybrid pixel detector with sub-nanosecond resolution

    Energy Technology Data Exchange (ETDEWEB)

    Thil, Ch., E-mail: christophe.thil@ziti.uni-heidelberg.d [Heidelberg University, Institute of Computer Engineering, B6, 26, 68161 Mannheim (Germany); Baron, A.Q.R. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Fajardo, P. [ESRF, Polygone Scientifique Louis Neel, 6, rue Jules Horowitz, 38000 Grenoble (France); Fischer, P. [Heidelberg University, Institute of Computer Engineering, B6, 26, 68161 Mannheim (Germany); Graafsma, H. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Rueffer, R. [ESRF, Polygone Scientifique Louis Neel, 6, rue Jules Horowitz, 38000 Grenoble (France)

    2011-02-01

    The fast response and the short recovery time of avalanche photodiodes (APDs) in linear mode make those devices ideal for direct X-ray detection in applications requiring high time resolution or counting rate. In order to provide position sensitivity, the XNAP project aims at creating a hybrid pixel detector with nanosecond time resolution based on a monolithic APD sensor array with 32 x32 pixels covering about 1 cm{sup 2} active area. The readout is implemented in a pixelated front-end ASIC suited for the readout of such arrays, matched to pixels of 280{mu}mx280{mu}m size. Every single channel features a fast transimpedance amplifier, a discriminator with locally adjustable threshold and two counters with high dynamic range and counting speed able to accumulate X-ray hits with no readout dead time. Additionally, the detector can be operated in list mode by time-stamping every single event with sub-nanosecond resolution. In a first phase of the project, a 4x4 pixel test module is built to validate the conceptual design of the detector. The XNAP project is briefly presented and the performance of the readout ASIC is discussed.

  14. Cloud track wind using synergism of backscatter lidar and sky digital picture

    Science.gov (United States)

    Khalesifard, Hamid R.; Abdi, Farhad; Flamant, Pierre H.

    2005-10-01

    Cloud altitude measurements by a 532nm backscatter Lidar and time lapsed digital photography are combined to monitor the cloud velocity profile. The cloud images are recorded in time steps of two seconds by a Nikon D100 digital camera through a 63° solid angle while the Lidar was measuring the cloud altitude. The images are recorded in 8 bits gray scale JPG format in an array of 2240×1488 pixels. To measure the angular displacement of different parts of the cloud, each image is meshed into an array of 44×29 cells, each cell contains 50×50 pixels. The grayscale density cross correlations between similar cells of successive images are computed using a MATLAB code developed by us for this application. The output products are the direction and the amount of displacement of each cell, in pixels. combining the results on cloud displacement with Lidar measurements enable to calculate the velocity vector in each cell. The resolution in velocity is about 1 ms-1 and 2° in direction. The calculation technique also is tested by simulating the cloud motion by moving the image pixels with a computer generated Gaussian velocity distribution.

  15. A digital accelerometer array utilizing suprathreshold stochastic resonance for detection of sub-Brownian noise floor accelerations.

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Dustin Wade; Olsson, Roy H.

    2004-12-01

    The goal of this LDRD project was to evaluate the possibilities of utilizing Stochastic resonance in micromechanical sensor systems as a means for increasing signal to noise for physical sensors. A careful study of this field reveals that in the case of a single sensing element, stochastic resonance offers no real advantage. We have, however, identified a system that can utilize very similar concepts to stochastic resonance in order to achieve an arrayed sensor system that could be superior to existing technologies in the field of inertial sensors, and could offer a very low power technique for achieving navigation grade inertial measurement units.

  16. Charge Pump Clock Generation PLL for the Data Output Block of the Upgraded ATLAS Pixel Front-End in 130 nm CMOS

    CERN Document Server

    Kruth, A; Arutinov, D; Barbero, M; Gronewald, M; Hemperek, T; Karagounis, M; Krueger, H; Wermes, N; Fougeron, D; Menouni, M; Beccherle, R; Dube, S; Ellege, D; Garcia-Sciveres, M; Gnani, D; Mekkaoui, A; Gromov, V; Kluit, R; Schipper, J

    2009-01-01

    FE-I4 is the 130 nm ATLAS pixel IC currently under development for upgraded Large Hadron Collider (LHC) luminosities. FE-I4 is based on a low-power analog pixel array and digital architecture concepts tuned to higher hit rates [1]. An integrated Phase Locked Loop (PLL) has been developed that locally generates a clock signal for the 160 Mbit/s output data stream from the 40 MHz bunch crossing reference clock. This block is designed for low power, low area consumption and recovers quickly from loss of lock related to single-event transients in the high radiation environment of the ATLAS pixel detector. After a general introduction to the new FE-I4 pixel front-end chip, this work focuses on the FE-I4 output blocks and on a first PLL prototype test chip submitted in early 2009. The PLL is nominally operated from a 1.2V supply and consumes 3.84mW of DC power. Under nominal operating conditions, the control voltage settles to within 2% of its nominal value in less than 700 ns. The nominal operating frequency for t...

  17. Challenges of small-pixel infrared detectors: a review

    Science.gov (United States)

    Rogalski, A.; Martyniuk, P.; Kopytko, M.

    2016-04-01

    In the last two decades, several new concepts for improving the performance of infrared detectors have been proposed. These new concepts particularly address the drive towards the so-called high operating temperature focal plane arrays (FPAs), aiming to increase detector operating temperatures, and as a consequence reduce the cost of infrared systems. In imaging systems with the above megapixel formats, pixel dimension plays a crucial role in determining critical system attributes such as system size, weight and power consumption (SWaP). The advent of smaller pixels has also resulted in the superior spatial and temperature resolution of these systems. Optimum pixel dimensions are limited by diffraction effects from the aperture, and are in turn wavelength-dependent. In this paper, the key challenges in realizing optimum pixel dimensions in FPA design including dark current, pixel hybridization, pixel delineation, and unit cell readout capacity are outlined to achieve a sufficiently adequate modulation transfer function for the ultra-small pitches involved. Both photon and thermal detectors have been considered. Concerning infrared photon detectors, the trade-offs between two types of competing technology—HgCdTe material systems and III-V materials (mainly barrier detectors)—have been investigated.

  18. High frame rate measurements of semiconductor pixel detector readout IC

    Science.gov (United States)

    Szczygiel, R.; Grybos, P.; Maj, P.

    2012-07-01

    We report on high count rate and high frame rate measurements of a prototype IC named FPDR90, designed for readouts of hybrid pixel semiconductor detectors used for X-ray imaging applications. The FPDR90 is constructed in 90 nm CMOS technology and has dimensions of 4 mm×4 mm. Its main part is a matrix of 40×32 pixels with 100 μm×100 μm pixel size. The chip works in the single photon counting mode with two discriminators and two 16-bit ripple counters per pixel. The count rate per pixel depends on the effective CSA feedback resistance and can be set up to 6 Mcps. The FPDR90 can operate in the continuous readout mode, with zero dead time. Due to the architecture of digital blocks in pixel, one can select the number of bits read out from each counter from 1 to 16. Because in the FPDR90 prototype only one data output is available, the frame rate is 9 kfps and 72 kfps for 16 bits and 1 bit readout, respectively (with nominal clock frequency of 200 MHz).

  19. High frame rate measurements of semiconductor pixel detector readout IC

    Energy Technology Data Exchange (ETDEWEB)

    Szczygiel, R., E-mail: robert.szczygiel@agh.edu.pl [AGH University of Science and Technology, Department of Measurement and Instrumentation, Al. Mickiewicza 30, 30-059 Cracow (Poland); Grybos, P.; Maj, P. [AGH University of Science and Technology, Department of Measurement and Instrumentation, Al. Mickiewicza 30, 30-059 Cracow (Poland)

    2012-07-11

    We report on high count rate and high frame rate measurements of a prototype IC named FPDR90, designed for readouts of hybrid pixel semiconductor detectors used for X-ray imaging applications. The FPDR90 is constructed in 90 nm CMOS technology and has dimensions of 4 mm Multiplication-Sign 4 mm. Its main part is a matrix of 40 Multiplication-Sign 32 pixels with 100 {mu}m Multiplication-Sign 100 {mu}m pixel size. The chip works in the single photon counting mode with two discriminators and two 16-bit ripple counters per pixel. The count rate per pixel depends on the effective CSA feedback resistance and can be set up to 6 Mcps. The FPDR90 can operate in the continuous readout mode, with zero dead time. Due to the architecture of digital blocks in pixel, one can select the number of bits read out from each counter from 1 to 16. Because in the FPDR90 prototype only one data output is available, the frame rate is 9 kfps and 72 kfps for 16 bits and 1 bit readout, respectively (with nominal clock frequency of 200 MHz).

  20. Hadamard Transform Spectrometer Mixed Pixels' Unmixing Method%哈达玛变换光谱仪混合像元解混方法研究

    Institute of Scientific and Technical Information of China (English)

    闫鹏; 胡炳樑; 刘学斌; 孙威; 李立波; 冯玉涛; 刘永征

    2011-01-01

    哈达玛变换光谱成像仪是一种采用多通道探测的数字变换光谱技术,介绍了基于数字微镜阵列器件(DMD)的哈达玛变换光谱仪工作原理与仪器结构,对成像传感器所获得的混合像元进行了分析研究,理论推导出了混叠像元的解混合方法,仿真实验结果表明该方法简单有效,对提高混合像元复原光谱精度超过10%.%Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery.

  1. Development of a high density pixel multichip module at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, G. [and others

    2001-03-08

    At Fermilab, both pixel detector multichip module and sensor hybridization are being developed for the BTeV experiment. The BTeV pixel detector is based on a design relying on a hybrid approach. With this approach, the readout chip and the sensor array are developed separately and the detector is constructed by flip-chip mating the two together. This method offers maximum flexibility in the development process, choice of fabrication technologies, and the choice of sensor material. This paper presents strategies to handle the required data rate and performance results of the first prototype and detector hybridization.

  2. Contact CMOS imaging of gaseous oxygen sensor array.

    Science.gov (United States)

    Daivasagaya, Daisy S; Yao, Lei; Yi Yung, Ka; Hajj-Hassan, Mohamad; Cheung, Maurice C; Chodavarapu, Vamsy P; Bright, Frank V

    2011-10-01

    We describe a compact luminescent gaseous oxygen (O2) sensor microsystem based on the direct integration of sensor elements with a polymeric optical filter and placed on a low power complementary metal-oxide semiconductor (CMOS) imager integrated circuit (IC). The sensor operates on the measurement of excited-state emission intensity of O2-sensitive luminophore molecules tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) ([Ru(dpp)3](2+)) encapsulated within sol-gel derived xerogel thin films. The polymeric optical filter is made with polydimethylsiloxane (PDMS) that is mixed with a dye (Sudan-II). The PDMS membrane surface is molded to incorporate arrays of trapezoidal microstructures that serve to focus the optical sensor signals on to the imager pixels. The molded PDMS membrane is then attached with the PDMS color filter. The xerogel sensor arrays are contact printed on top of the PDMS trapezoidal lens-like microstructures. The CMOS imager uses a 32 × 32 (1024 elements) array of active pixel sensors and each pixel includes a high-gain phototransistor to convert the detected optical signals into electrical currents. Correlated double sampling circuit, pixel address, digital control and signal integration circuits are also implemented on-chip. The CMOS imager data is read out as a serial coded signal. The CMOS imager consumes a static power of 320 µW and an average dynamic power of 625 µW when operating at 100 Hz sampling frequency and 1.8 V DC. This CMOS sensor system provides a useful platform for the development of miniaturized optical chemical gas sensors.

  3. Improving detector spatial resolution using pixelated scintillators with a barrier rib structure

    Science.gov (United States)

    Liu, Langechuan; Lu, Minghui; Cao, Wanqing; Peng, Luke; Chen, Arthur

    2016-03-01

    Indirect conversion flat panel detectors (FPDs) based on amorphous silicon (a-Si) technology are widely used in digital X-ray imaging. In such FPDs a scintillator layer is used for converting X-rays into visible light photons. However, the lateral spread of these photons inside the scintillator layer reduces spatial resolution of the FPD. In this study, FPDs incorporating pixelated scintillators with a barrier rib structure were developed to limit lateral spread of light photons thereby improving spatial resolution. For the pixelated scintillator, a two-dimensional barrier rib structure was first manufactured on a substrate layer, coated with reflective materials, and filled to the rim with the scintillating material of gadolinium oxysulfide (GOS). Several scintillator samples were fabricated, with pitch size varying from 160 to 280 μm and rib height from 200 to 280 μm. The samples were directly coupled to an a-Si flat panel photodiode array with a pitch of 200 μm to convert optical photons to electronic signals. With the pixelated scintillator, the detector modulation transfer function was shown to improve significantly (by 94% at 2 cycle/mm) compared to a detector using an unstructured GOS layer. However, the prototype does show lower sensitivity due to the decrease in scintillator fill factor. The preliminary results demonstrated the feasibility of using the barrier-rib structure to improve the spatial resolution of FPDs. Such an improvement would greatly benefit nondestructive testing applications where the spatial resolution is the most important parameter. Further investigation will focus on improving the detector sensitivity and exploring its medical applications.

  4. Compensation of PVT Variations in ToF Imagers with In-Pixel TDC

    Directory of Open Access Journals (Sweden)

    Ion Vornicu

    2017-05-01

    Full Text Available The design of a direct time-of-flight complementary metal-oxide-semiconductor (CMOS image sensor (dToF-CIS based on a single-photon avalanche-diode (SPAD array with an in-pixel time-to-digital converter (TDC must contemplate system-level aspects that affect its overall performance. This paper provides a detailed analysis of the impact of process parameters, voltage supply, and temperature (PVT variations on the time bin of the TDC array. Moreover, the design and characterization of a global compensation loop is presented. It is based on a phase locked loop (PLL that is integrated on-chip. The main building block of the PLL is a voltage-controlled ring-oscillator (VCRO that is identical to the ones employed for the in-pixel TDCs. The reference voltage that drives the master VCRO is distributed to the voltage control inputs of the slave VCROs such that their multiphase outputs become invariant to PVT changes. These outputs act as time interpolators for the TDCs. Therefore the compensation scheme prevents the time bin of the TDCs from drifting over time due to the aforementioned factors. Moreover, the same scheme is used to program different time resolutions of the direct time-of-flight (ToF imager aimed at 3D ranging or depth map imaging. Experimental results that validate the analysis are provided as well. The compensation loop proves to be remarkably effective. The spreading of the TDCs time bin is lowered from: (i 20% down to 2.4% while the temperature ranges from 0 °C to 100 °C; (ii 27% down to 0.27%, when the voltage supply changes within ±10% of the nominal value; (iii 5.2 ps to 2 ps standard deviation over 30 sample chips, due to process parameters’ variation.

  5. 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.

  6. Performance of a carbon nanotube field emission X-ray source array for stationary digital breast tomosynthesis

    Science.gov (United States)

    Gidcumb, Emily Morgan

    This work describes the performance of a stationary digital breast tomosynthesis (s-DBT) X-ray tube based on carbon nanotube (CNT) cathodes, and the imaging system developed around it. The s-DBT system has the potential to improve the detection and diagnosis of breast cancer over commercially available digital breast tomosynthesis (DBT) systems. DBT is growing in popularity in the United States, and around the world, as a potential replacement for traditional 2D mammography. The main advantage of DBT over 2D mammography lies in the pseudo-3D nature of the technique allowing the removal of overlapping breast tissue within the image. s-DBT builds on this advantage by removing blur from focal spot motion. Introductions to breast imaging techniques and the DBT modality are given, followed by an introduction to carbon nanotube field emission, the foundation of the s-DBT technology. Details of the s-DBT X-ray tube design and system integration are discussed including specific design parameters, system requirements, and the development process. Also included are summaries of the X-ray tube and system performance over time, and results from characterization measurements. Specific focus is given to the development and completion of a fabrication procedure for tungsten gate mesh, characterization of the CNT cathodes, and improving the system's spatial resolution with use of the focusing electrodes. The tungsten gate mesh is an essential component for extracting electrons from CNTs. A successful deep reactive ion etching fabrication procedure was developed, and the improved gate mesh allowed for higher cathode current and longer pulse widths to be employed in the s-DBT system. Characterization of the CNT cathodes revealed their high-current capacity and the ability to produce relatively long pulse widths, mimicking a 2D imaging modality. This work confirmed that the cathodes are well suited for the task of breast imaging, and explored possible improvements. Lastly, it was

  7. Alignment method for solar collector arrays

    Science.gov (United States)

    Driver, Jr., Richard B

    2012-10-23

    The present invention is directed to an improved method for establishing camera fixture location for aligning mirrors on a solar collector array (SCA) comprising multiple mirror modules. The method aligns the mirrors on a module by comparing the location of the receiver image in photographs with the predicted theoretical receiver image location. To accurately align an entire SCA, a common reference is used for all of the individual module images within the SCA. The improved method can use relative pixel location information in digital photographs along with alignment fixture inclinometer data to calculate relative locations of the fixture between modules. The absolute locations are determined by minimizing alignment asymmetry for the SCA. The method inherently aligns all of the mirrors in an SCA to the receiver, even with receiver position and module-to-module alignment errors.

  8. MSDAR光纤传输与同步研究%Fibre-Optic Transmission and Synchronization of Multi-Station Digital Array Radar

    Institute of Scientific and Technical Information of China (English)

    龙伟军; 龚树凤; 贲德

    2013-01-01

    多基站数字阵雷达面临信号远距传输、时序同步与信号分集等技术难题.本文针对MSDAR构建了具有较强适用性的光纤同步系统.该系统采用信号分级同步策略对时序信号逐级同步,精度可达纳秒量级.采用多级复用技术显著提高单纤信道传输容量以解决MSDAR信号分集问题.本文分析了影响光纤传输同步性的诸方面因素,结合数字阵雷达原理建立了信号同步性对雷达性能影响的关系模型.详细分析了同步性对雷达波束指向影响.结果表明光纤同步系统若满足MSDAR系统需求,须折中考虑系统工作频率、带宽、通道等系统参数,定量的结果可由模型给出.%Multi-station digital array radar (MSDAR) confronts with several puzzles such as distant transmission,timing synchronization,signal distribution and collection.A universal fibre-optic transmission synchronization and signal diversity system is architected,which exploits hierarchical synchronization approaches to achieve precise synchronization of nanosecond magnitude.Hierarchical channel multiplex techniques are designed to promote the fibre-optic channel capacity to address the signal diversity difficulties of MSDAR.Based on the analysis of effects on synchronization and the characteristics of digital array radar (DAR),the mathematic models of the relationship between synchronization and radar performances are built.According to the models,the beam pointing errors are estimated.The theoretical analysis and simulation results indicate that the fibre-optic transmission synchronization system can satisfy high frequency MSDAR,but with the increase of operation frequency and bandwidth,the effects will be more serious and the quantitative results can be calculated on the models.

  9. A Low Power Digital Accumulation Technique for Digital-Domain CMOS TDI Image Sensor

    Science.gov (United States)

    Yu, Changwei; Nie, Kaiming; Xu, Jiangtao; Gao, Jing

    2016-01-01

    In this paper, an accumulation technique suitable for digital domain CMOS time delay integration (TDI) image sensors is proposed to reduce power consumption without degrading the rate of imaging. In terms of the slight variations of quantization codes among different pixel exposures towards the same object, the pixel array is divided into two groups: one is for coarse quantization of high bits only, and the other one is for fine quantization of low bits. Then, the complete quantization codes are composed of both results from the coarse-and-fine quantization. The equivalent operation comparably reduces the total required bit numbers of the quantization. In the 0.18 µm CMOS process, two versions of 16-stage digital domain CMOS TDI image sensor chains based on a 10-bit successive approximate register (SAR) analog-to-digital converter (ADC), with and without the proposed technique, are designed. The simulation results show that the average power consumption of slices of the two versions are 6.47×10-8 J/line and 7.4×10-8 J/line, respectively. Meanwhile, the linearity of the two versions are 99.74% and 99.99%, respectively. PMID:27669256

  10. A Low Power Digital Accumulation Technique for Digital-Domain CMOS TDI Image Sensor.

    Science.gov (United States)

    Yu, Changwei; Nie, Kaiming; Xu, Jiangtao; Gao, Jing

    2016-09-23

    In this paper, an accumulation technique suitable for digital domain CMOS time delay integration (TDI) image sensors is proposed to reduce power consumption without degrading the rate of imaging. In terms of the slight variations of quantization codes among different pixel exposures towards the same object, the pixel array is divided into two groups: one is for coarse quantization of high bits only, and the other one is for fine quantization of low bits. Then, the complete quantization codes are composed of both results from the coarse-and-fine quantization. The equivalent operation comparably reduces the total required bit numbers of the quantization. In the 0.18 µm CMOS process, two versions of 16-stage digital domain CMOS TDI image sensor chains based on a 10-bit successive approximate register (SAR) analog-to-digital converter (ADC), with and without the proposed technique, are designed. The simulation results show that the average power consumption of slices of the two versions are 6 . 47 × 10 - 8 J/line and 7 . 4 × 10 - 8 J/line, respectively. Meanwhile, the linearity of the two versions are 99.74% and 99.99%, respectively.

  11. Photon-Counting Arrays for Time-Resolved Imaging

    Directory of Open Access Journals (Sweden)

    I. Michel Antolovic

    2016-06-01

    Full Text Available The paper presents a camera comprising 512 × 128 pixels capable of single-photon detection and gating with a maximum frame rate of 156 kfps. The photon capture is performed through a gated single-photon avalanche diode that generates a digital pulse upon photon detection and through a digital one-bit counter. Gray levels are obtained through multiple counting and accumulation, while time-resolved imaging is achieved through a 4-ns gating window controlled with subnanosecond accuracy by a field-programmable gate array. The sensor, which is equipped with microlenses to enhance its effective fill factor, was electro-optically characterized in terms of sensitivity and uniformity. Several examples of capture of fast events are shown to demonstrate the suitability of the approach.

  12. Pixel detector system development at Diamond Light Source

    Science.gov (United States)

    Marchal, J.; Horswell, I.; Gimenez, E. N.; Tartoni, N.

    2010-10-01

    Hybrid pixel detectors consisting of an array of silicon photodiodes bump-bonded to CMOS read-out chips provide high signal-to-noise ratio and high dynamic range compared to CCD-based detectors and Image Plates. These detector features are important for SAXS experiments where a wide range of intensities are present in the images. For time resolved SAXS experiments, high frame rates are compulsory. The latest CMOS read-out chip developed by the MEDIPIX collaboration provides high frame rate and continuous acquisition mode. A read-out system for an array of MEDIPIX3 sensors is under development at Diamond Light Source. This system will support a full resolution frame rate of 1 kHz at a pixel counter depth of 12-bit and a frame rate of 30 kHz at a counter depth of 1 bit. Details concerning system design and MEDIPIX sensors characterization are presented.

  13. Integrated Lens Antennas for Multi-Pixel Receivers

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam

    2011-01-01

    Future astrophysics and planetary experiments are expected to require large focal plane arrays with thousands of detectors. Feedhorns have excellent performance, but their mass, size, fabrication challenges, and expense become prohibitive for very large focal plane arrays. Most planar antenna designs produce broad beam patterns, and therefore require additional elements for efficient coupling to the telescope optics, such as substrate lenses or micromachined horns. An antenna array with integrated silicon microlenses that can be fabricated photolithographically effectively addresses these issues. This approach eliminates manual assembly of arrays of lenses and reduces assembly errors and tolerances. Moreover, an antenna array without metallic horns will reduce mass of any planetary instrument significantly. The design has a monolithic array of lens-coupled, leaky-wave antennas operating in the millimeter- and submillimeter-wave frequencies. Electromagnetic simulations show that the electromagnetic fields in such lens-coupled antennas are mostly confined in approximately 12 15 . This means that one needs to design a small-angle sector lens that is much easier to fabricate using standard lithographic techniques, instead of a full hyper-hemispherical lens. Moreover, this small-angle sector lens can be easily integrated with the antennas in an array for multi-pixel imager and receiver implementation. The leaky antenna is designed using double-slot irises and fed with TE10 waveguide mode. The lens implementation starts with a silicon substrate. Photoresist with appropriate thickness (optimized for the lens size) is spun on the substrate and then reflowed to get the desired lens structure. An antenna array integrated with individual lenses for higher directivity and excellent beam profile will go a long way in realizing multi-pixel arrays and imagers. This technology will enable a new generation of compact, low-mass, and highly efficient antenna arrays for use in multi-pixel

  14. Fabrication of Electrophoretic Display Driven by Membrane Switch Array

    Science.gov (United States)

    Senda, Kazuo; Usui, Hiroaki

    2010-04-01

    Electrophoretic devices (EPDs) and organic light-emitting diodes (OLEDs) have potential application in a large-area flexible displays, such as digital signage. For this purpose, a new backplane is capable of driving a large unit is required instead of thin-film transistors. In this paper we describe the fabrication of a membrane switch array suitable for driving large-scale flat-panel displays. An array of membrane switches was prepared using flexible printed circuit (FPC) technology of polyimide films, by combining low-temperature processes of lamination and copper electroplating methods. An array of 256 matrix switches with a pixel size of 7 mm2 was prepared to drive the EPD front panel. The switches were driven at a voltage of about 40 V and a frequency of 10 Hz. The operation characteristics agreed well with the result of the theoretical calculation. The calculation also suggested that driving voltage can be lowered by increasing pixel size. The contact resistance of the membrane switch was as low as 0.2 Ω, which implies the wide applicability of this device for driving a variety of elements.

  15. Initial performance studies of a wearable brain positron emission tomography camera based on autonomous thin-film digital Geiger avalanche photodiode arrays.

    Science.gov (United States)

    Schmidtlein, Charles R; Turner, James N; Thompson, Michael O; Mandal, Krishna C; Häggström, Ida; Zhang, Jiahan; Humm, John L; Feiglin, David H; Krol, Andrzej

    2017-01-01

    Using analytical and Monte Carlo modeling, we explored performance of a lightweight wearable helmet-shaped brain positron emission tomography (PET), or BET camera, based on thin-film digital Geiger avalanche photodiode arrays with Lutetium-yttrium oxyorthosilicate (LYSO) or [Formula: see text] scintillators for imaging in vivo human brain function of freely moving and acting subjects. We investigated a spherical cap BET and cylindrical brain PET (CYL) geometries with 250-mm diameter. We also considered a clinical whole-body (WB) LYSO PET/CT scanner. The simulated energy resolutions were 10.8% (LYSO) and 3.3% ([Formula: see text]), and the coincidence window was set at 2 ns. The brain was simulated as a water sphere of uniform F-18 activity with a radius of 100 mm. We found that BET achieved [Formula: see text] better noise equivalent count (NEC) performance relative to the CYL and [Formula: see text] than WB. For 10-mm-thick [Formula: see text] equivalent mass systems, LYSO (7-mm thick) had [Formula: see text] higher NEC than [Formula: see text]. We found that [Formula: see text] scintillator crystals achieved [Formula: see text] full-width-half-maximum spatial resolution without parallax errors. Additionally, our simulations showed that LYSO generally outperformed [Formula: see text] for NEC unless the timing resolution for [Formula: see text] was considerably smaller than that presently used for LYSO, i.e., well below 300 ps.

  16. Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation.

    Science.gov (United States)

    Rong, Lu; Latychevskaia, Tatiana; Wang, Dayong; Zhou, Xun; Huang, Haochong; Li, Zeyu; Wang, Yunxin

    2014-07-14

    We report here on terahertz (THz) digital holography on a biological specimen. A continuous-wave (CW) THz in-line holographic setup was built based on a 2.52 THz CO(2) pumped THz laser and a pyroelectric array detector. We introduced novel statistical method of obtaining true intensity values for the pyroelectric array detector's pixels. Absorption and phase-shifting images of a dragonfly's hindwing were reconstructed simultaneously from single in-line hologram. Furthermore, we applied phase retrieval routines to eliminate twin image and enhanced the resolution of the reconstructions by hologram extrapolation beyond the detector area. The finest observed features are 35 μm width cross veins.

  17. A CMOS active pixel sensor for retinal stimulation

    Science.gov (United States)

    Prydderch, Mark L.; French, Marcus J.; Mathieson, Keith; Adams, Christopher; Gunning, Deborah; Laudanski, Jonathan; Morrison, James D.; Moodie, Alan R.; Sinclair, James

    2006-02-01

    Degenerative photoreceptor diseases, such as age-related macular degeneration and retinitis pigmentosa, are the most common causes of blindness in the western world. A potential cure is to use a microelectronic retinal prosthesis to provide electrical stimulation to the remaining healthy retinal cells. We describe a prototype CMOS Active Pixel Sensor capable of detecting a visual scene and translating it into a train of electrical pulses for stimulation of the retina. The sensor consists of a 10 x 10 array of 100 micron square pixels fabricated on a 0.35 micron CMOS process. Light incident upon each pixel is converted into output current pulse trains with a frequency related to the light intensity. These outputs are connected to a biocompatible microelectrode array for contact to the retinal cells. The flexible design allows experimentation with signal amplitudes and frequencies in order to determine the most appropriate stimulus for the retina. Neural processing in the retina can be studied by using the sensor in conjunction with a Field Programmable Gate Array (FPGA) programmed to behave as a neural network. The sensor has been integrated into a test system designed for studying retinal response. We present the most recent results obtained from this sensor.

  18. A 1024×768-12μm Digital ROIC for uncooled microbolometer FPAs

    Science.gov (United States)

    Eminoglu, Selim

    2017-02-01

    This paper reports the development of a new digital microbolometer Readout Integrated Circuit (D-ROIC), called MT10212BD. It has a format of 1024 × 768 (XGA) and a pixel pitch of 12μm. MT10212BD is Mikro Tasarim's second 12μm pitch microbolometer ROIC, which is developed specifically for surface micro machined microbolometer detector arrays with small pixel pitch using high-TCR pixel materials, such as VOx and a Si. MT10212BD has an alldigital system on-chip architecture, which generates programmable timing and biasing, and performs 14-bit analog to digital conversion (ADC). The signal processing chain in the ROIC is composed of pixel bias circuitry, integrator based programmable gain amplifier followed by column parallel ADC circuitry. MT10212BD has a serial programming interface that can be used to configure the programmable ROIC features and to load the Non-Uniformity-Correction (NUC) date to the ROIC. MT10212BD has a total of 8 high-speed serial digital video outputs, which can be programmed to operate in the 2, 4, and 8-output modes and can support frames rates above 60 fps. The high-speed serial digital outputs supports data rates as high as 400 Mega-bits/s, when operated at 50 MHz system clock frequency. There is an on-chip phase-locked-loop (PLL) based timing circuitry to generate the high speed clocks used in the ROIC. The ROIC is designed to support pixel resistance values ranging from 30KΩ to 90kΩ, with a nominal value of 60KΩ. The ROIC has a globally programmable gain in the column readout, which can be adjusted based on the detector resistance value.

  19. WFC3 Pixel Area Maps

    Science.gov (United States)

    Kalirai, J. S.; Cox, C.; Dressel, L.; Fruchter, A.; Hack, W.; Kozhurina-Platais, V.; Mack, J.

    2010-04-01

    We present the pixel area maps (PAMs) for the WFC3/UVIS and WFC3/IR detectors, and discuss the normalization of these images. HST processed flt images suffer from geometric distortion and therefore have pixel areas that vary on the sky. The counts (electrons) measured for a source on these images depends on the position of the source on the detector, an effect that is implicitly corrected when these images are multidrizzled into drz files. The flt images can be multiplied by the PAMs to yield correct and uniform counts for a given source irrespective of its location on the image. To ensure consistency between the count rate measured for sources in drz images and near the center of flt images, we set the normalization of the PAMs to unity at a reference pixel near the center of the UVIS mosaic and IR detector, and set the SCALE in the IDCTAB equal to the square root of the area of this reference pixel. The implications of this choice for photometric measurements are discussed.

  20. VNR CMS Pixel detector replacement

    CERN Document Server

    2017-01-01

    Joel Butler, spokesperson of the CMS collaboration explains how a team from many different partner institutes installed a new detector in CMS. This detector is the silicon pixel detector and they’ve been working on it for about five years, to replace one of our existing detectors. This detectors measures particles closer to the beam than any of the other components of this huge detector behind me. It gives us the most precise picture of tracks as they come out of the collisions and expand and travel through the detector. This particular device has twice as many pixels, 120 million, as opposed to about 68 million in the old detector and it can take data faster and pump it out to the analysis more quickly. 00’53’’ Images of the descent, insertion and installation of first piece of the Pixel detector on Tue Feb 28. Images of the descent, insertion and installation of second piece of the Pixel and the two cylinders being joined.

  1. Silicon PIN diode hybrid arrays for charged particle detection: Building blocks for vertex detectors at the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, G.; Gaalema, S.; Shapiro, S.L.; Dunwoodie, W.M.; Arens, J.F.; Jernigan, J.G.

    1989-05-01

    Two-dimensional arrays of solid state detectors have long been used in visible and infrared systems. Hybrid arrays with separately optimized detector and readout substrates have been extensively developed for infrared sensors. The characteristics and use of these infrared readout chips with silicon PIN diode arrays produced by MICRON SEMICONDUCTOR for detecting high-energy particles are reported. Some of these arrays have been produced in formats as large as 512 /times/ 512 pixels; others have been radiation hardened to total dose levels beyond 1 Mrad. Data generation rates of 380 megasamples/second have been achieved. Analog and digital signal transmission and processing techniques have also been developed to accept and reduce these high data rates. 9 refs., 15 figs., 2 tabs.

  2. Status of the ATLAS pixel detector

    CERN Document Server

    Saavedra Aldo, F

    2005-01-01

    The ATLAS pixel detector is currently being constructed and will be installed in 2006 to be ready for commissioning at the Large Hadron Collider. The complete pixel detector is composed of three concentric barrels and six disks that are populated by 1744 ATLAS Pixel modules. The main components of the pixel module are the readout electronics and the silicon sensor whose active region is instrumented with rectangular pixels. The module has been designed to be able to survive 10 years of operation within the ATLAS detector. A brief description of the pixel detector will be presented with results and problems encountered during the production stage.

  3. Circuit design for the retina-like image sensor based on space-variant lens array

    Science.gov (United States)

    Gao, Hongxun; Hao, Qun; Jin, Xuefeng; Cao, Jie; Liu, Yue; Song, Yong; Fan, Fan

    2013-12-01

    Retina-like image sensor is based on the non-uniformity of the human eyes and the log-polar coordinate theory. It has advantages of high-quality data compression and redundant information elimination. However, retina-like image sensors based on the CMOS craft have drawbacks such as high cost, low sensitivity and signal outputting efficiency and updating inconvenience. Therefore, this paper proposes a retina-like image sensor based on space-variant lens array, focusing on the circuit design to provide circuit support to the whole system. The circuit includes the following parts: (1) A photo-detector array with a lens array to convert optical signals to electrical signals; (2) a strobe circuit for time-gating of the pixels and parallel paths for high-speed transmission of the data; (3) a high-precision digital potentiometer for the I-V conversion, ratio normalization and sensitivity adjustment, a programmable gain amplifier for automatic generation control(AGC), and a A/D converter for the A/D conversion in every path; (4) the digital data is displayed on LCD and stored temporarily in DDR2 SDRAM; (5) a USB port to transfer the data to PC; (6) the whole system is controlled by FPGA. This circuit has advantages as lower cost, larger pixels, updating convenience and higher signal outputting efficiency. Experiments have proved that the grayscale output of every pixel basically matches the target and a non-uniform image of the target is ideally achieved in real time. The circuit can provide adequate technical support to retina-like image sensors based on space-variant lens array.

  4. Cosmic ray effects in microcalorimeter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Stahle, C.K. E-mail: cak@lheapop.gsfc.nasa.gov; Boyce, K.R.; Brown, G.V.; Cottam, J.; Figueroa-Feliciano, E.; Galeazzi, M.; Kelley, R.L.; McCammon, D.; Porter, F.S.; Szymkowiak, A.E.; Tillotson, W.A

    2004-03-11

    We have identified signals resulting from cosmic rays and environmental gamma rays depositing energy in the pixels and in the silicon frame of the Astro-E2/X-Ray Spectrometer microcalorimeter array. Coincidences between pixels and between the array and an anti-coincidence detector determined the nature of the events. Pulse shapes and amplitudes from the cosmic ray events helped refine the thermal model of the array chip. We discuss how future arrays can be optimized either for the greatest background rejection or for the highest source count rates.

  5. Characterizing pixel and point patterns with a hyperuniformity disorder length

    Science.gov (United States)

    Chieco, A. T.; Dreyfus, R.; Durian, D. J.

    2017-09-01

    We introduce the concept of a "hyperuniformity disorder length" h that controls the variance of volume fraction fluctuations for randomly placed windows of fixed size. In particular, fluctuations are determined by the average number of particles within a distance h from the boundary of the window. We first compute special expectations and bounds in d dimensions, and then illustrate the range of behavior of h versus window size L by analyzing several different types of simulated two-dimensional pixel patterns—where particle positions are stored as a binary digital image in which pixels have value zero if empty and one if they contain a particle. The first are random binomial patterns, where pixels are randomly flipped from zero to one with probability equal to area fraction. These have long-ranged density fluctuations, and simulations confirm the exact result h =L /2 . Next we consider vacancy patterns, where a fraction f of particles on a lattice are randomly removed. These also display long-range density fluctuations, but with h =(L /2 )(f /d ) for small f , and h =L /2 for f →1 . And finally, for a hyperuniform system with no long-range density fluctuations, we consider "Einstein patterns," where each particle is independently displaced from a lattice site by a Gaussian-distributed amount. For these, at large L ,h approaches a constant equal to about half the root-mean-square displacement in each dimension. Then we turn to gray-scale pixel patterns that represent simulated arrangements of polydisperse particles, where the volume of a particle is encoded in the value of its central pixel. And we discuss the continuum limit of point patterns, where pixel size vanishes. In general, we thus propose to quantify particle configurations not just by the scaling of the density fluctuation spectrum but rather by the real-space spectrum of h (L ) versus L . We call this approach "hyperuniformity disorder length spectroscopy".

  6. The ATLAS Silicon Pixel Sensors

    CERN Document Server

    Alam, M S; Einsweiler, K F; Emes, J; Gilchriese, M G D; Joshi, A; Kleinfelder, S A; Marchesini, R; McCormack, F; Milgrome, O; Palaio, N; Pengg, F; Richardson, J; Zizka, G; Ackers, M; Andreazza, A; Comes, G; Fischer, P; Keil, M; Klasen, V; Kühl, T; Meuser, S; Ockenfels, W; Raith, B; Treis, J; Wermes, N; Gössling, C; Hügging, F G; Wüstenfeld, J; Wunstorf, R; Barberis, D; Beccherle, R; Darbo, G; Gagliardi, G; Gemme, C; Morettini, P; Musico, P; Osculati, B; Parodi, F; Rossi, L; Blanquart, L; Breugnon, P; Calvet, D; Clemens, J-C; Delpierre, P A; Hallewell, G D; Laugier, D; Mouthuy, T; Rozanov, A; Valin, I; Aleppo, M; Caccia, M; Ragusa, F; Troncon, C; Lutz, Gerhard; Richter, R H; Rohe, T; Brandl, A; Gorfine, G; Hoeferkamp, M; Seidel, SC; Boyd, GR; Skubic, P L; Sícho, P; Tomasek, L; Vrba, V; Holder, M; Ziolkowski, M; D'Auria, S; del Papa, C; Charles, E; Fasching, D; Becks, K H; Lenzen, G; Linder, C

    2001-01-01

    Prototype sensors for the ATLAS silicon pixel detector have been developed. The design of the sensors is guided by the need to operate them in the severe LHC radiation environment at up to several hundred volts while maintaining a good signal-to-noise ratio, small cell size, and minimal multiple scattering. The ability to be operated under full bias for electrical characterization prior to the attachment of the readout integrated circuit electronics is also desired.

  7. SAR Image Complex Pixel Representations

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    Complex pixel values for Synthetic Aperture Radar (SAR) images of uniform distributed clutter can be represented as either real/imaginary (also known as I/Q) values, or as Magnitude/Phase values. Generally, these component values are integers with limited number of bits. For clutter energy well below full-scale, Magnitude/Phase offers lower quantization noise than I/Q representation. Further improvement can be had with companding of the Magnitude value.

  8. 数字阵列收发组件FPGA远程配置的研究与实现%Realization of FPGA Remote Configuration of T/R Modules for Digital Array Radar

    Institute of Scientific and Technical Information of China (English)

    李冬芳

    2011-01-01

    Digital array radar(DAR) becomes an important development direction of phased array radar. The digital array T/R module(DAM) is the core of DAR. Digital array radar has a large number of DAM modules, which are usually integrated with the array antenna and installed outside the aircraft. This results in difficulties in debugging. A design method for FPGA remote updating and configurating files is presented in this paper. Flash memory is used to store configuration data and CPLD device to generate FPGA configuration timing and multiplexing the optical fiber, which solves the problem of remotely debugging the DAMs. The dynamic reconfiguration technology has greatly improved the efficiency of the system test. It has been successfully applied in a demonstration project of digital array radar and achieves good results.%数字阵列雷达(DAR)正成为相控阵雷达的一个重要发展方向,数字阵列收发组件(DAM)是其核心。针对数字阵列雷达DAM模块数量众多,通常与阵列天线集成安装在舱外导致调试困难的实际情况,给出了一种数字阵列收发组件现场可编程门阵列(FPGA)远程配置的设计方法,利用Flash存储配置数据、CPLD产生配置时序和通信接口、复用系统通信光纤,较好地解决了DAM模块远程调试的难题,动态重构技术的应用极大地提高了系统的试验效率,在某数字阵列雷达演示验证项目中得到成功应用,取得了良好的效果。

  9. Terahertz Array Receivers with Integrated Antennas

    Science.gov (United States)

    Chattopadhyay, Goutam; Llombart, Nuria; Lee, Choonsup; Jung, Cecile; Lin, Robert; Cooper, Ken B.; Reck, Theodore; Siles, Jose; Schlecht, Erich; Peralta, Alessandro; Thomas, Bertrand; Mehdi, Imran

    2011-01-01

    Highly sensitive terahertz heterodyne receivers have been mostly single-pixel. However, now there is a real need of multi-pixel array receivers at these frequencies driven by the science and instrument requirements. In this paper we explore various receiver font-end and antenna architectures for use in multi-pixel integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies has progressed very well over the past few years. Novel stacking of micro-machined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages has made it possible to design multi-pixel heterodyne arrays. One of the critical technologies to achieve fully integrated system is the antenna arrays compatible with the receiver array architecture. In this paper we explore different receiver and antenna architectures for multi-pixel heterodyne and direct detector arrays for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  10. How big is an OMI pixel?

    Science.gov (United States)

    de Graaf, Martin; Sihler, Holger; Tilstra, Lieuwe G.; Stammes, Piet

    2016-08-01

    The Ozone Monitoring Instrument (OMI) is a push-broom imaging spectrometer, observing solar radiation backscattered by the Earth's atmosphere and surface. The incoming radiation is detected using a static imaging CCD (charge-coupled device) detector array with no moving parts, as opposed to most of the previous satellite spectrometers, which used a moving mirror to scan the Earth in the across-track direction. The field of view (FoV) of detector pixels is the solid angle from which radiation is observed, averaged over the integration time of a measurement. The OMI FoV is not quadrangular, which is common for scanning instruments, but rather super-Gaussian shaped and overlapping with the FoV of neighbouring pixels. This has consequences for pixel-area-dependent applications, like cloud fraction products, and visualisation.The shapes and sizes of OMI FoVs were determined pre-flight by theoretical and experimental tests but never verified after launch. In this paper the OMI FoV is characterised using collocated MODerate resolution Imaging Spectroradiometer (MODIS) reflectance measurements. MODIS measurements have a much higher spatial resolution than OMI measurements and spectrally overlap at 469 nm. The OMI FoV was verified by finding the highest correlation between MODIS and OMI reflectances in cloud-free scenes, assuming a 2-D super-Gaussian function with varying size and shape to represent the OMI FoV. Our results show that the OMPIXCOR product 75FoV corner coordinates are accurate as the full width at half maximum (FWHM) of a super-Gaussian FoV model when this function is assumed. The softness of the function edges, modelled by the super-Gaussian exponents, is different in both directions and is view angle dependent.The optimal overlap function between OMI and MODIS reflectances is scene dependent and highly dependent on time differences between overpasses, especially with clouds in the scene. For partially clouded scenes, the optimal overlap function was

  11. Development of hybrid photon detectors with integrated silicon pixel readout for the RICH counters of LHCb

    CERN Document Server

    Alemi, M; Formenti, F; Gys, Thierry; Piedigrossi, D; Puertolas, D; Rosso, E; Snoeys, W; Wyllie, Ken H

    1999-01-01

    We report on the ongoing work towards a hybrid photon detector with integrated silicon pixel readout for the ring imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN. The photon detector is based $9 on a cross-focussed image intensifier tube geometry where the image is de-magnified by a factor of 4. The anode consists of a silicon pixel array, bump-bonded to a fast, binary readout chip with matching pixel electronics. The $9 performance of a half-scale prototype is presented, together with the developments and tests of a full-scale tube with large active area. Specific requirements for pixel front-end and readout electronics in LHCb are outlined, and $9 recent results obtained from pixel chips applicable to hybrid photon detector design are summarized.

  12. MONOLITHIC ACTIVE PIXEL MATRIX WITH BINARY COUNTERS IN AN SOI PROCESS.

    Energy Technology Data Exchange (ETDEWEB)

    DUPTUCH,G.; YAREMA, R.

    2007-06-07

    The design of a Prototype monolithic active pixel matrix, designed in a 0.15 {micro}m CMOS SOI Process, is presented. The process allowed connection between the electronics and the silicon volume under the layer of buried oxide (BOX). The small size vias traversing through the BOX and implantation of small p-type islands in the n-type bulk result in a monolithic imager. During the acquisition time, all pixels register individual radiation events incrementing the counters. The counting rate is up to 1 MHz per pixel. The contents of counters are shifted out during the readout phase. The designed prototype is an array of 64 x 64 pixels and the pixel size is 26 x 26 {micro}m{sup 2}.

  13. Pixel size and pitch measurements of liquid crystal spatial light modulator by optical diffraction

    Indian Academy of Sciences (India)

    Ravinder Kumar Banyal; B Raghavendra Prasad

    2005-08-01

    We present a simple technique for the determination of pixel size and pitch of liquid crystal (LC) based spatial light modulator (SLM). The proposed method is based on optical diffraction from pixelated LC panel that has been modeled as a two-dimensional array of rectangular apertures. A novel yet simple, two-plane measurement technique is implemented to circumvent the difficulty in absolute distance measurement. Experimental results are presented for electrically addressed twisted nematic LC-SLM removed from the display projector.

  14. Modulator and VCSEL-MSM smart pixels for parallel pipeline networking and signal processing

    Science.gov (United States)

    Chen, C.-H.; Hoanca, Bogdan; Kuznia, C. B.; Pansatiankul, Dhawat E.; Zhang, Liping; Sawchuk, Alexander A.

    1999-07-01

    TRANslucent Smart Pixel Array (TRANSPAR) systems perform high performance parallel pipeline networking and signal processing based on optical propagation of 3D data packets. The TRANSPAR smart pixel devices use either self-electro- optic effect GaAs multiple quantum well modulators or CMOS- VCSEL-MSM (CMOS-Vertical Cavity Surface Emitting Laser- Metal-Semiconductor-Metal) technology. The data packets transfer among high throughput photonic network nodes using multiple access/collision detection or token-ring protocols.

  15. SOI pixel circuits with synchronized TMC for time-of-flight stigmatic imaging mass spectrometry

    CERN Document Server

    Watanabe, Kaori; Fujita, Youichi; Arai, Yasuo; Hazama, Hisanao

    2015-01-01

    We propose SOI pixel circuits with a synchronized time memory cell (TMC) for time-of-flight stigmatic imaging mass spectrometry. The circuits simultaneously detect the position and the fine/coarse flight time of an ion for the MALDI-ToF mass spectrometer. We discuss the circuit design and present the simulation results of a prototype detector comprised of a 32 x 32 pixel array in which each pixel pitch is 40 um and the time resolution is a minimum of 1 ns. The results of transient analysis demonstrate the fully correct synchronous operation at a 100-MHz clock frequency and simultaneous 32-word SRAM writing.

  16. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    Science.gov (United States)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2015-11-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a scalable solution for 100 to 1000 pixel systems with 14 bit resolution and record-lengths of 128k frames has been developed. HyperV is applying these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 14 bit depth. Preliminary experimental results as well as future plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  17. CVD diamond pixel detectors for LHC experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wedenig, R.; 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.; Procario, M.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Runolfsson, O.; Russ, J.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trawick, M.; Trischuk, W.; Vittone, E.; Wagner, A.; Walsh, A.M.; Weilhammer, P.; White, C.; Zeuner, W.; Ziock, H.; Zoeller, M.; Blanquart, L.; Breugnion, P.; Charles, E.; Ciocio, A.; Clemens, J.C.; Dao, K.; Einsweiler, K.; Fasching, D.; Fischer, P.; Joshi, A.; Keil, M.; Klasen, V.; Kleinfelder, S.; Laugier, D.; Meuser, S.; Milgrome, O.; Mouthuy, T.; Richardson, J.; Sinervo, P.; Treis, J.; Wermes, N

    1999-08-01

    This paper reviews the development of CVD diamond pixel detectors. The preparation of the diamond pixel sensors for bump-bonding to the pixel readout electronics for the LHC and the results from beam tests carried out at CERN are described.

  18. CMS has a heart of pixels

    CERN Multimedia

    2003-01-01

    In the immediate vicinity of the collision point, CMS will be equipped with pixel detectors consisting of no fewer than 50 million pixels measuring 150 microns along each side. Each of the pixels, which receive the signal, is connected to its own electronic circuit by a tiny sphere (seen here in the electron microscope image) measuring 15 to 20 microns in diameter.

  19. Photovoltaic Pixels for Neural Stimulation: Circuit Models and Performance.

    Science.gov (United States)

    Boinagrov, David; Lei, Xin; Goetz, Georges; Kamins, Theodore I; Mathieson, Keith; Galambos, Ludwig; Harris, James S; Palanker, Daniel

    2016-02-01

    Photovoltaic conversion of pulsed light into pulsed electric current enables optically-activated neural stimulation with miniature wireless implants. In photovoltaic retinal prostheses, patterns of near-infrared light projected from video goggles onto subretinal arrays of photovoltaic pixels are converted into patterns of current to stimulate the inner retinal neurons. We describe a model of these devices and evaluate the performance of photovoltaic circuits, including the electrode-electrolyte interface. Characteristics of the electrodes measured in saline with various voltages, pulse durations, and polarities were modeled as voltage-dependent capacitances and Faradaic resistances. The resulting mathematical model of the circuit yielded dynamics of the electric current generated by the photovoltaic pixels illuminated by pulsed light. Voltages measured in saline with a pipette electrode above the pixel closely matched results of the model. Using the circuit model, our pixel design was optimized for maximum charge injection under various lighting conditions and for different stimulation thresholds. To speed discharge of the electrodes between the pulses of light, a shunt resistor was introduced and optimized for high frequency stimulation.

  20. Phase 1 upgrade of the CMS Pixel Detector

    CERN Document Server

    Saha, Anirban

    2016-01-01

    The pixel tracker of the Compact Muon Solenoid (CMS) experiment is the innermost sub-detector, located close to the collision point, and is used for reconstruction of the tracks and vertices of charged particles. The present pixel detector was designed to work efficiently with the maximum instantaneous luminosity of $\\rm 1 \\times 10^{34}$ cm$^{-2}$ s$^{-1}$. In 2017 the Large Hadron Collider (LHC) is expected to deliver a peak luminosity reaching up to $\\rm 2\\times10^{34} cm^{-2}s^{-1}$, increasing the mean number of primary vertices to 50. Due to the radiation damage and significant data losses due to high occupancy in the readout chip of the pixel detector, the present system must be replaced by a new one in an extended end-of-year shutdown during winter 2016/2017 in order to maintain the excellent tracking and other physics performances. The main new features of the upgraded pixel detector are the a ultra-light mechanical design with four barrel layers and three end-cap disks, digital readout chip with hi...

  1. Phase 1 upgrade of the CMS pixel detector

    Science.gov (United States)

    Saha, Anirban

    2017-02-01

    The pixel tracker of the Compact Muon Solenoid (CMS) experiment is the innermost sub-detector, located close to the collision point, and is used for reconstruction of the tracks and vertices of charged particles. The present pixel detector was designed to work efficiently with the maximum instantaneous luminosity of 1 × 1034 cm‑2 s‑1. In 2017 the Large Hadron Collider (LHC) is expected to deliver a peak luminosity reaching up to 2 × 1034 cm‑2 s‑1, increasing the mean number of primary vertices to 50. Due to the radiation damage and significant data losses due to high occupancy in the readout chip of the pixel detector, the present system must be replaced by a new one in an extended end-of-year shutdown during winter 2016/2017 in order to maintain the excellent tracking and other physics performances. The main new features of the upgraded pixel detector are a ultra-light mechanical design with four barrel layers and three end-cap disks, digital readout chip with higher rate capability and a new cooling system. In this document, we discuss the motivations for the upgrade, the design, and technological choices made, the status of the construction of the new detector and the future plans for the installation and commissioning.

  2. Research and Development of Monolithic Active Pixel Sensors for the Detection of the Elementary Particles; Recherche et developpement de capteurs actifs monolithiques CMOS pour la detection de particules elementaires

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y

    2007-09-15

    In order to develop high spatial resolution and readout speed vertex detectors for the future International Linear Collider (ILC), fast CMOS Monolithic Active Pixel Sensors (MAPS) are studied on this work. Two prototypes of MAPS, MIMOSA 8 and MIMOSA 16, based on the same micro-electronic architecture were developed in CMOS processes with different thickness of epitaxial layer. The size of pixel matrix is 32 x 128: 8 columns of the pixel array are readout directly with analog outputs and the other 24 columns are connected to the column level auto-zero discriminators. The Correlated Double Sampling (CDS) structures are successfully implemented inside pixel and discriminator. The photo diode type pixels with different diode sizes are used in these prototypes. With a {sup 55}Fe X-ray radioactive source, the important parameters, such as Temporal Noise, Fixed Pattern Noise (FPN), Signal-to-Noise Ratio (SNR), Charge-to-Voltage conversion Factor (CVF) and Charge Collection Efficiency (CCE), are studied as function of readout speed and diode size. For MIMOSA 8, the effect of fast neutrons irradiation is also. Two beam tests campaigns were made: at DESY with a 5 GeV electrons beam and at CERN with a 180 GeV pions beam. Detection Efficiency and Spatial Resolution are studied in function of the discriminator threshold. For these two parameters, the influences of diode size and SNR of the central pixel of a cluster are also discussed. In order to improve the spatial resolution of the digital outputs, a very compact (25 {mu}m x 1 mm) and low consumption (300 {mu}W) column level ADC is designed in AMS 0.35 {mu}m OPTO process. Based on successive approximation architecture, the auto-offset cancellation structure is integrated. A new column level auto-zero discriminator using static latch is also designed. (author)

  3. Design and characterization of a 256 x 64-pixel single-photon imager in CMOS for a MEMS-based laser scanning time-of-flight sensor.

    Science.gov (United States)

    Niclass, Cristiano; Ito, Kota; Soga, Mineki; Matsubara, Hiroyuki; Aoyagi, Isao; Kato, Satoru; Kagami, Manabu

    2012-05-21

    We introduce an optical time-of-flight image sensor taking advantage of a MEMS-based laser scanning device. Unlike previous approaches, our concept benefits from the high timing resolution and the digital signal flexibility of single-photon pixels in CMOS to allow for a nearly ideal cooperation between the image sensor and the scanning device. This technique enables a high signal-to-background light ratio to be obtained, while simultaneously relaxing the constraint on size of the MEMS mirror. These conditions are critical for devising practical and low-cost depth sensors intended to operate in uncontrolled environments, such as outdoors. A proof-of-concept prototype capable of operating in real-time was implemented. This paper focuses on the design and characterization of a 256 x 64-pixel image sensor, which also comprises an event-driven readout circuit, an array of 64 row-level high-throughput time-to-digital converters, and a 16 Gbit/s global readout circuit. Quantitative evaluation of the sensor under 2 klux of background light revealed a repeatability error of 13.5 cm throughout the distance range of 20 meters.

  4. Spatio-spectral color filter array design for optimal image recovery.

    Science.gov (United States)

    Hirakawa, Keigo; Wolfe, Patrick J

    2008-10-01

    In digital imaging applications, data are typically obtained via a spatial subsampling procedure implemented as a color filter array-a physical construction whereby only a single color value is measured at each pixel location. Owing to the growing ubiquity of color imaging and display devices, much recent work has focused on the implications of such arrays for subsequent digital processing, including in particular the canonical demosaicking task of reconstructing a full color image from spatially subsampled and incomplete color data acquired under a particular choice of array pattern. In contrast to the majority of the demosaicking literature, we consider here the problem of color filter array design and its implications for spatial reconstruction quality. We pose this problem formally as one of simultaneously maximizing the spectral radii of luminance and chrominance channels subject to perfect reconstruction, and-after proving sub-optimality of a wide class of existing array patterns-provide a constructive method for its solution that yields robust, new panchromatic designs implementable as subtractive colors. Empirical evaluations on multiple color image test sets support our theoretical results, and indicate the potential of these patterns to increase spatial resolution for fixed sensor size, and to contribute to improved reconstruction fidelity as well as significantly reduced hardware complexity.

  5. 1-D array of perforated diode neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    McNeil, Walter J. [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: wjm4444@ksu.edu; Bellinger, Steven L.; Unruh, Troy C.; Henderson, Chris M.; Ugorowski, Phil; Morris-Lee, Bryce [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States); Taylor, Russell D. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: mcgregor@ksu.edu

    2009-06-01

    Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 {mu}m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with {sup 6}LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.

  6. Making a trillion pixels dance

    Science.gov (United States)

    Singh, Vivek; Hu, Bin; Toh, Kenny; Bollepalli, Srinivas; Wagner, Stephan; Borodovsky, Yan

    2008-03-01

    In June 2007, Intel announced a new pixelated mask technology. This technology was created to address the problem caused by the growing gap between the lithography wavelength and the feature sizes patterned with it. As this gap has increased, the quality of the image has deteriorated. About a decade ago, Optical Proximity Correction (OPC) was introduced to bridge this gap, but as this gap continued to increase, one could not rely on the same basic set of techniques to maintain image quality. The computational lithography group at Intel sought to alleviate this problem by experimenting with additional degrees of freedom within the mask. This paper describes the resulting pixelated mask technology, and some of the computational methods used to create it. The first key element of this technology is a thick mask model. We realized very early in the development that, unlike traditional OPC methods, the pixelated mask would require a very accurate thick mask model. Whereas in the traditional methods, one can use the relatively coarse approximations such as the boundary layer method, use of such techniques resulted not just in incorrect sizing of parts of the pattern, but in whole features missing. We built on top of previously published domain decomposition methods, and incorporated limitations of the mask manufacturing process, to create an accurate thick mask model. Several additional computational techniques were invoked to substantially increase the speed of this method to a point that it was feasible for full chip tapeout. A second key element of the computational scheme was the comprehension of mask manufacturability, including the vital issue of the number of colors in the mask. While it is obvious that use of three or more colors will give the best image, one has to be practical about projecting mask manufacturing capabilities for such a complex mask. To circumvent this serious issue, we eventually settled on a two color mask - comprising plain glass and etched

  7. First Light with a 67-Million-Pixel WFI Camera

    Science.gov (United States)

    1999-01-01

    The newest astronomical instrument at the La Silla observatory is a super-camera with no less than sixty-seven million image elements. It represents the outcome of a joint project between the European Southern Observatory (ESO) , the Max-Planck-Institut für Astronomie (MPI-A) in Heidelberg (Germany) and the Osservatorio Astronomico di Capodimonte (OAC) near Naples (Italy), and was installed at the 2.2-m MPG/ESO telescope in December 1998. Following careful adjustment and testing, it has now produced the first spectacular test images. With a field size larger than the Full Moon, the new digital Wide Field Imager is able to obtain detailed views of extended celestial objects to very faint magnitudes. It is the first of a new generation of survey facilities at ESO with which a variety of large-scale searches will soon be made over extended regions of the southern sky. These programmes will lead to the discovery of particularly interesting and unusual (rare) celestial objects that may then be studied with large telescopes like the VLT at Paranal. This will in turn allow astronomers to penetrate deeper and deeper into the many secrets of the Universe. More light + larger fields = more information! The larger a telescope is, the more light - and hence information about the Universe and its constituents - it can collect. This simple truth represents the main reason for building ESO's Very Large Telescope (VLT) at the Paranal Observatory. However, the information-gathering power of astronomical equipment can also be increased by using a larger detector with more image elements (pixels) , thus permitting the simultaneous recording of images of larger sky fields (or more details in the same field). It is for similar reasons that many professional photographers prefer larger-format cameras and/or wide-angle lenses to the more conventional ones. The Wide Field Imager at the 2.2-m telescope Because of technological limitations, the sizes of detectors most commonly in use in

  8. Urban Image Classification: Per-Pixel Classifiers, Sub-Pixel Analysis, Object-Based Image Analysis, and Geospatial Methods. 10; Chapter

    Science.gov (United States)

    Myint, Soe W.; Mesev, Victor; Quattrochi, Dale; Wentz, Elizabeth A.

    2013-01-01

    Remote sensing methods used to generate base maps to analyze the urban environment rely predominantly on digital sensor data from space-borne platforms. This is due in part from new sources of high spatial resolution data covering the globe, a variety of multispectral and multitemporal sources, sophisticated statistical and geospatial methods, and compatibility with GIS data sources and methods. The goal of this chapter is to review the four groups of classification methods for digital sensor data from space-borne platforms; per-pixel, sub-pixel, object-based (spatial-based), and geospatial methods. Per-pixel methods are widely used methods that classify pixels into distinct categories based solely on the spectral and ancillary information within that pixel. They are used for simple calculations of environmental indices (e.g., NDVI) to sophisticated expert systems to assign urban land covers. Researchers recognize however, that even with the smallest pixel size the spectral information within a pixel is really a combination of multiple urban surfaces. Sub-pixel classification methods therefore aim to statistically quantify the mixture of surfaces to improve overall classification accuracy. While within pixel variations exist, there is also significant evidence that groups of nearby pixels have similar spectral information and therefore belong to the same classification category. Object-oriented methods have emerged that group pixels prior to classification based on spectral similarity and spatial proximity. Classification accuracy using object-based methods show significant success and promise for numerous urban 3 applications. Like the object-oriented methods that recognize the importance of spatial proximity, geospatial methods for urban mapping also utilize neighboring pixels in the classification process. The primary difference though is that geostatistical methods (e.g., spatial autocorrelation methods) are utilized during both the pre- and post

  9. Pixel-by-pixel VIS/NIR and LIR sensor fusion system

    Science.gov (United States)

    Zhang, Evan; Zhang, James S.; Song, Vivian W.; Chin, Ken P.; Hu, Gelbert

    2003-01-01

    Visible (VIS) camera (such as CCD) or Near Infrared (NIR) camera (such as low light level CCD or image intensifier) has high resolution and is easy to distinguish enemy and foe, but it cannot see through thin fog/cloud, heavy smoke/dust, foliage, camouflage, and darkness. The Long Infrared (LIR) imager can overcome above problems, but the resolution is too low and it cannot see the NIR aiming light from enemy. The best solution is to fuse the VIS/NIR and LIR sensors to overcome their shortcomings and take advantages of both sensors. In order to see the same target without parallax, the fusio system must have a common optical aperature. In this paper, three common optical apertures are designed: common reflective objective lens, common beam splitter, and common transmissive objective lens. The first one has very small field of view and the second one needs two heads, so the best choice is the third one, but we must find suitable optical materials and correct the color aberrations from 0.6 to 12 μ. It is a tough job. By choosing ZnSe as the first common piece of the objective lens and using glass for NIR and Ge (or IR glass) for LIR as rest pieces, we only need to and are able to correct the aberrations from 0.6 to 1.0 μ for NIR and from 8 to 12 μ for LIR. Finally, a common reflective objective lens and the common beam splitter are also successfully designed. Five application examples are given. In the digital signal processing, we use only one Altera chip. After inserting data, scaling the image size, and adjusting the signal level, the LIR will have the same format and same pixel number of the VIS/NIR, so real-time pixel-by-pixel sensor fusion is realized. The digital output can be used for further image processing and automatic target recognition, such as if we overlap the LIR image on the VIS/NIR image for missile guidance or rifle sight we don't need to worry about the time and the environment again. A gum-size wireless transmitter is also designed that is

  10. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  11. Image pixel device using integrated organic electronic components

    Science.gov (United States)

    Swathi, K.; Narayan, K. S.

    2016-11-01

    We report a solution processed, monolithically integrated device similar to an imaging pixel element used in complementary metal-oxide semiconductor (CMOS) based cameras. This integrated pixel essentially consists of a pair of organic photodiode (OPD) and organic field effect transistor (OFET). The signal generated by the light responsive OPD drives the OFET to different output states to quantify the light intensity. The prerequisite of a low operating voltage OFET (polymer semiconductor and a self-assembled hybrid dielectric layer. A bulk heterojunction blend was used as the photo-active layer in the OPD along with suitable buffer layers for charge extraction. The material parameters were optimized to realize a suitable structure which clearly demonstrated the interplay of the OPD and OFET operations, thereby forming a roadmap for all-organic CMOS arrays.

  12. Bonding techniques for hybrid active pixel sensors (HAPS)

    Science.gov (United States)

    Bigas, M.; Cabruja, E.; Lozano, M.

    2007-05-01

    A hybrid active pixel sensor (HAPS) consists of an array of sensing elements which is connected to an electronic read-out unit. The most used way to connect these two different devices is bump bonding. This interconnection technique is very suitable for these systems because it allows a very fine pitch and a high number of I/Os. However, there are other interconnection techniques available such as direct bonding. This paper, as a continuation of a review [M. Lozano, E. Cabruja, A. Collado, J. Santander, M. Ullan, Nucl. Instr. and Meth. A 473 (1-2) (2001) 95-101] published in 2001, presents an update of the different advanced bonding techniques available for manufacturing a hybrid active pixel detector.

  13. Image Encryption based on the RGB PIXEL Transposition and Shuffling

    Directory of Open Access Journals (Sweden)

    Quist Aphetsi Kester

    2013-06-01

    Full Text Available Privacy is one of the key issues information Security addresses. Through encryption one can prevent a third party from understanding raw data during signal transmission. The encryption methods for enhancing the security of digital contents has gained high significance in the current era of breach of security and misuse of the confidential information intercepted and misused by the unauthorized parties. This paper sets out to contribute to the general body of knowledge in the area of cryptography application and by developing a cipher algorithm for image encryption of m*n size by shuffling the RGB pixel values. The algorithm ultimately makes it possible for encryption and decryption of the images based on the RGB pixel. The algorithm was implemented using MATLAB.

  14. Compressive sensing spectroscopy with a single pixel camera.

    Science.gov (United States)

    Starling, David J; Storer, Ian; Howland, Gregory A

    2016-07-01

    Spectrometry requires high spectral resolution and high photometric precision while also balancing cost and complexity. We address these requirements by employing a compressive-sensing camera capable of improving signal acquisition speed and sensitivity in limited signal scenarios. In particular, we implement a fast single pixel spectrophotometer with no moving parts and measure absorption and emission spectra comparable with commercial products. Our method utilizes Hadamard matrices to sample the spectra and then minimizes the total variation of the signal. The experimental setup includes standard optics and a grating, a low-cost digital micromirror device, and an intensity detector. The resulting spectrometer produces a 512 pixel spectrum with low mean-squared error and up to a 90% reduction in data acquisition time when compared with a standard spectrophotometer.

  15. Study of the CMS Phase 1 Pixel Pilot Blade Reconstruction

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The silicon pixel detector is the innermost component of the CMS tracking system. It was replaced in March 2017 with an upgraded one, called the Phase 1 upgrade detector. During Long Shutdown 1, a third disk was inserted into the present forward pixel detector with eight prototype blades constructed using a new digital read-out chip architecture and a prototype readout chain. Testing the performance of these pilot modules enabled us to gain experience with the Phase 1 upgrade modules. In this document, the data reconstruction with the pilot system is presented. The hit finding efficiency and residual of these new modules is also shown, and how these observables were used to adjust the timing of the pilot blades.

  16. New SOFRADIR 10μm pixel pitch infrared products

    Science.gov (United States)

    Lefoul, X.; Pere-Laperne, N.; Augey, T.; Rubaldo, L.; Aufranc, Sébastien; Decaens, G.; Ricard, N.; Mazaleyrat, E.; Billon-Lanfrey, D.; Gravrand, Olivier; Bisotto, Sylvette

    2014-10-01

    Recent advances in miniaturization of IR imaging technology have led to a growing market for mini thermal-imaging sensors. In that respect, Sofradir development on smaller pixel pitch has made much more compact products available to the users. When this competitive advantage is mixed with smaller coolers, made possible by HOT technology, we achieved valuable reductions in the size, weight and power of the overall package. At the same time, we are moving towards a global offer based on digital interfaces that provides our customers simplifications at the IR system design process while freeing up more space. This paper discusses recent developments on hot and small pixel pitch technologies as well as efforts made on compact packaging solution developed by SOFRADIR in collaboration with CEA-LETI.

  17. Design Optimization of Pixel Structure for α-Si based Uncooled Infrared Detector

    Directory of Open Access Journals (Sweden)

    Sudha Gupta

    2013-11-01

    Full Text Available In this paper authors present the design and simulation results achieved for pixel structure of amorphous Si (α-Si based bolometer array. Most uncooled IR detectors in the world are based on VOx material. But this is not a standard material in IC technology and has many inherent disadvantages. The α-Si, an alternative material with high TCR is becoming as popular. However, large TCR values, in this material are achieved only in films of high resistivity. To achieve TCR value more than 2.5%/K, α-Si film resistivity is ~ 80 ohms-cm. This gives rise to very large pixel resistance of the order of 100 Mega ohms depending upon the design of the leg structure. This high pixel resistance causes very large noise and hence lower sensitivity. If leg width or membrane thickness is increased in order to reduce the pixel resistance, then this results in higher thermal conductance which also decreases sensitivity. To overcome this problem, pixel structure is so designed that within a pixel, only part of the electrical conduction is through α-Si and rest is through metal. Simulation using Coventorware software has been done to optimize pixel resistance as well as thermal conductance through legs so that maximum sensitivity could be obtained. Optimization is also carried out in order to reduce sensitivity of pixel resistance to variation in material resistivity.

  18. Design of a Low-Light-Level Image Sensor with On-Chip Sigma-Delta Analog-to- Digital Conversion

    Science.gov (United States)

    Mendis, Sunetra K.; Pain, Bedabrata; Nixon, Robert H.; Fossum, Eric R.

    1993-01-01

    The design and projected performance of a low-light-level active-pixel-sensor (APS) chip with semi-parallel analog-to-digital (A/D) conversion is presented. The individual elements have been fabricated and tested using MOSIS* 2 micrometer CMOS technology, although the integrated system has not yet been fabricated. The imager consists of a 128 x 128 array of active pixels at a 50 micrometer pitch. Each column of pixels shares a 10-bit A/D converter based on first-order oversampled sigma-delta (Sigma-Delta) modulation. The 10-bit outputs of each converter are multiplexed and read out through a single set of outputs. A semi-parallel architecture is chosen to achieve 30 frames/second operation even at low light levels. The sensor is designed for less than 12 e^- rms noise performance.

  19. Design of a Low-Light-Level Image Sensor with On-Chip Sigma-Delta Analog-to- Digital Conversion

    Science.gov (United States)

    Mendis, Sunetra K.; Pain, Bedabrata; Nixon, Robert H.; Fossum, Eric R.

    1993-01-01

    The design and projected performance of a low-light-level active-pixel-sensor (APS) chip with semi-parallel analog-to-digital (A/D) conversion is presented. The individual elements have been fabricated and tested using MOSIS* 2 micrometer CMOS technology, although the integrated system has not yet been fabricated. The imager consists of a 128 x 128 array of active pixels at a 50 micrometer pitch. Each column of pixels shares a 10-bit A/D converter based on first-order oversampled sigma-delta (Sigma-Delta) modulation. The 10-bit outputs of each converter are multiplexed and read out through a single set of outputs. A semi-parallel architecture is chosen to achieve 30 frames/second operation even at low light levels. The sensor is designed for less than 12 e^- rms noise performance.

  20. The ALICE pixel detector upgrade

    Science.gov (United States)

    Reidt, F.

    2016-12-01

    The ALICE experiment at the CERN LHC is designed to study the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma, using proton-proton, proton-nucleus and nucleus-nucleus collisions. The ALICE collaboration is preparing a major upgrade of the experimental apparatus to be installed during the second long LHC shutdown in the years 2019-2020. A key element of the ALICE upgrade is the new, ultra-light, high-resolution Inner Tracking System. With respect to the current detector, the new Inner Tracking System will significantly enhance the pointing resolution, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be obtained by seven concentric detector layers based on a Monolithic Active Pixel Sensor with a pixel pitch of about 30×30 μm2. A key feature of the new Inner Tracking System, which is optimised for high tracking accuracy at low transverse momenta, is the very low mass of the three innermost layers, which feature a material budget of 0.3% X0 per layer. This contribution presents the design goals and layout of the upgraded ALICE Inner Tracking System, summarises the R&D activities focussing on the technical implementation of the main detector components, and the projected detector performance.

  1. Serial powering of pixel modules

    CERN Document Server

    Stockmanns, Tobias; Hügging, Fabian Georg; Peric, I; Runólfsson, O; Wermes, Norbert

    2003-01-01

    Modern pixel detectors for the next generation of high-energy collider experiments like LHC use readout electronics in deep sub- micron technology. Chips in this technology need a low supply voltage of 2-2.5 V alongside high current consumption to achieve the desired performance. The high supply current leads to significant voltage drops in the long and low mass supply cables so that voltage fluctuations at the chips are induced, when the supply current changes. This problem scales with the number of modules when connected in parallel to the power supplies. An alternative powering scheme connects several modules in series resulting in a higher supply voltage but a lower current consumption of the chain and therefore a much lower voltage drop in the cables. In addition the amount of cables needed to supply the detector is vastly reduced. The concept and features of serial powering are presented and studies of the implementation of this technology as an alternative for the ATLAS pixel detector are shown. In par...

  2. A CMOS Active Pixel Sensor for Charged Particle Detection

    Energy Technology Data Exchange (ETDEWEB)

    Matis, Howard S.; Bieser, Fred; Kleinfelder, Stuart; Rai, Gulshan; Retiere, Fabrice; Ritter, Hans George; Singh, Kunal; Wurzel, Samuel E.; Wieman, Howard; Yamamoto, Eugene

    2002-12-02

    Active Pixel Sensor (APS) technology has shown promise for next-generation vertex detectors. This paper discusses the design and testing of two generations of APS chips. Both are arrays of 128 by 128 pixels, each 20 by 20 {micro}m. Each array is divided into sub-arrays in which different sensor structures (4 in the first version and 16 in the second) and/or readout circuits are employed. Measurements of several of these structures under Fe{sup 55} exposure are reported. The sensors have also been irradiated by 55 MeV protons to test for radiation damage. The radiation increased the noise and reduced the signal. The noise can be explained by shot noise from the increased leakage current and the reduction in signal is due to charge being trapped in the epi layer. Nevertheless, the radiation effect is small for the expected exposures at RHIC and RHIC II. Finally, we describe our concept for mechanically supporting a thin silicon wafer in an actual detector.

  3. SNR improvement for hyperspectral application using frame and pixel binning

    Science.gov (United States)

    Rehman, Sami Ur; Kumar, Ankush; Banerjee, Arup

    2016-05-01

    Hyperspectral imaging spectrometer systems are increasingly being used in the field of remote sensing for variety of civilian and military applications. The ability of such instruments in discriminating finer spectral features along with improved spatial and radiometric performance have made such instruments a powerful tool in the field of remote sensing. Design and development of spaceborne hyper spectral imaging spectrometers poses lot of technological challenges in terms of optics, dispersion element, detectors, electronics and mechanical systems. The main factors that define the type of detectors are the spectral region, SNR, dynamic range, pixel size, number of pixels, frame rate, operating temperature etc. Detectors with higher quantum efficiency and higher well depth are the preferred choice for such applications. CCD based Si detectors serves the requirement of high well depth for VNIR band spectrometers but suffers from smear. Smear can be controlled by using CMOS detectors. Si CMOS detectors with large format arrays are available. These detectors generally have smaller pitch and low well depth. Binning technique can be used with available CMOS detectors to meet the large swath, higher resolution and high SNR requirements. Availability of larger dwell time of satellite can be used to bin multiple frames to increase the signal collection even with lesser well depth detectors and ultimately increase the SNR. Lab measurements reveal that SNR improvement by frame binning is more in comparison to pixel binning. Effect of pixel binning as compared to the frame binning will be discussed and degradation of SNR as compared to theoretical value for pixel binning will be analyzed.

  4. Proceedings of PIXEL98 -- International pixel detector workshop

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.F.; Kwan, S. [eds.

    1998-08-01

    Experiments around the globe face new challenges of more precision in the face of higher interaction rates, greater track densities, and higher radiation doses, as they look for rarer and rarer processes, leading many to incorporate pixelated solid-state detectors into their plans. The highest-readout rate devices require new technologies for implementation. This workshop reviewed recent, significant progress in meeting these technical challenges. Participants presented many new results; many of them from the weeks--even days--just before the workshop. Brand new at this workshop were results on cryogenic operation of radiation-damaged silicon detectors (dubbed the Lazarus effect). Other new work included a diamond sensor with 280-micron collection distance; new results on breakdown in p-type silicon detectors; testing of the latest versions of read-out chip and interconnection designs; and the radiation hardness of deep-submicron processes.

  5. A large-scale NEMS light-emitting array based on CVD graphene (Conference Presentation)

    Science.gov (United States)

    Kim, Hyungsik; Kim, Young Duck; Lee, Changhyuk; Lee, Sunwoo; Seo, Dong-jea; Jerng, Sahng-Kyoon; Chun, Seung-Hyun; Hone, James; Shepard, Kenneth L.

    2017-02-01

    Graphene has received much interest from optical communities largely owing to its photon-like linear energy band structure called Dirac cone. While majority of the recent research has dealt with plasmon and polariton of the two-dimensional material, a recently reported graphene light emitter could render a new dimension of applications, particularly in high-speed optical communication. Moreover chemical vapor deposition (CVD) growth technique for graphene is available today providing means for scalable high quality graphene. The reported graphene emitter provides broadband light emission from visible to mid-infrared which could be instrumental in multi-color display units and optical communications, however a truly large scale implementation has not previously been achieved. Here we demonstrate a CMOS-compatible 262,144 light-emitting pixels array (10 x 10 mm2) based on suspended CVD graphene nano-electro-mechanical systems (GNEMS). A single photoemission area is 19.6 µm2 and a unit pixel is consisting of 512 photoemission devices (16 x 16) where a multiplexer and a digital to analog converter (DAC) are used to control each pixel. This work clearly demonstrates scalability of multi-channel GNEMS light-emitting array, an atomically thin electro-optical module, and further paves a path for its commercial implementation transparent display or high-speed optical communication.

  6. Dual-mode optical microscope based on single-pixel imaging

    Science.gov (United States)

    Rodríguez, A. D.; Clemente, P.; Tajahuerce, E.; Lancis, J.

    2016-07-01

    We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.

  7. a Solution for Dosimetry and Quality Assurance in Imrt and Hadrontherapy:. the Pixel Ionization Chamber

    Science.gov (United States)

    Amerio, S.; Coda, S.; Nastasi, U.; Belletti, S.; Ghedi, B.; Boriano, A.; Cirio, R.; Luparia, A.; Marchetto, F.; Peroni, C.; Sanz Freire, C. J.; Donetti, M.; Madon, E.; Trevisiol, E.; Urgesi, A.

    2002-11-01

    The new radiotherapy techniques require new detectors to monitor and measure the clinical field. The Intensity Modulated Radiation Therapy (IMRT) techniques like step and shoot, sliding window, dynamic wedge or scanning beam add the time variable to the treatment field. In this case the water phantom with a single ionization chamber moving inside the field needs very long measurement time. Linear arrays of ionization chambers or diodes measure the field only along a line. 2D detectors like radiographic or gafchromic film are not suitable to be used as on line detectors. We have developed, built and tested an ionization chamber segmented in pixels that measure the dose in a plane at several points. Every channel has a dedicated electronic chain that digitizes the collected charge and data from all the channels are sent to the computer that performs the data acquisition. One read out cycle is very fast allowing to measure in real time the fluency and the shape of the field. The chamber can be used in two different ways, as monitor chamber and as relative dosemeter. A description of the detector, the electronics, and test results with both photon and hadron beams will be reported.

  8. Preliminary validation results of an ASIC for the readout and control of near-infrared large array detectors

    Science.gov (United States)

    Pâhlsson, Philip; Meier, Dirk; Otnes Berge, Hans Kristian; Øya, Petter; Steenari, David; Olsen, Alf; Hasanbegovic, Amir; Altan, Mehmet A.; Najafiuchevler, Bahram; Talebi, Jahanzad; Azman, Suleyman; Gheorghe, Codin; Ackermann, Jörg; Mæhlum, Gunnar

    2015-06-01

    In this paper we present initial test results of the Near Infrared Readout and Controller ASIC (NIRCA), designed for large area image sensors under contract from the European Space Agency (ESA) and the Norwegian Space Center. The ASIC is designed to read out image sensors based on mercury cadmium telluride (HgCdTe, or MCT) operating down to 77 K. IDEAS has developed, designed and initiated testing of NIRCA with promising results, showing complete functionality of all ASIC sub-components. The ASIC generates programmable digital signals to clock out the contents of an image array and to amplify, digitize and transfer the resulting pixel charge. The digital signals can be programmed into the ASIC during run-time and allows for windowing and custom readout schemes. The clocked out voltages are amplified by programmable gain amplifiers and digitized by 12-bit, 3-Msps successive approximation register (SAR) analogue-to-digital converters (ADC). Digitized data is encoded using 8-bit to 10-bit encoding and transferred over LVDS to the readout system. The ASIC will give European researchers access to high spectral sensitivity, very low noise and radiation hardened readout electronics for astronomy and Earth observation missions operating at 77 K and room temperature. The versatility of the chip makes the architecture a possible candidate for other research areas, or defense or industrial applications that require analog and digital acquisition, voltage regulation, and digital signal generation.

  9. Development of a pixel sensor with fine space-time resolution based on SOI technology for the ILC vertex detector

    Science.gov (United States)

    Ono, Shun; Togawa, Manabu; Tsuji, Ryoji; Mori, Teppei; Yamada, Miho; Arai, Yasuo; Tsuboyama, Toru; Hanagaki, Kazunori

    2017-02-01

    We have been developing a new monolithic pixel sensor with silicon-on-insulator (SOI) technology for the International Linear Collider (ILC) vertex detector system. The SOI monolithic pixel detector is realized using standard CMOS circuits fabricated on a fully depleted sensor layer. The new SOI sensor SOFIST can store both the position and timing information of charged particles in each 20×20 μm2 pixel. The position resolution is further improved by the position weighted with the charges spread to multiple pixels. The pixel also records the hit timing with an embedded time-stamp circuit. The sensor chip has column-parallel analog-to-digital conversion (ADC) circuits and zero-suppression logic for high-speed data readout. We are designing and evaluating some prototype sensor chips for optimizing and minimizing the pixel circuit.

  10. Design and realisation of integrated circuits for the readout of pixel sensors in high-energy physics and biomedical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Peric, I.

    2004-08-01

    Radiation tolerant pixel-readout chip for the ATLAS pixel detector has been designed, implemented in a deep-submicron CMOS technology and successfully tested. The chip contains readout-channels with complex analog and digital circuits. Chip for steering of the DEPFET active-pixel matrix has been implemented in a high-voltage CMOS technology. The chip contains channels which generate fast sequences of high-voltage signals. Detector containing this chip has been successfully tested. Pixel-readout test chip for an X-ray imaging pixel sensor has been designed, implemented in a CMOS technology and tested. Pixel-readout channels are able to simultaneously count the signals generated by passage of individual photons and to sum the total charge generated during exposure time. (orig.)

  11. A discrete component low-noise preamplifier readout for a linear (1×16) SiC photodiode array

    Energy Technology Data Exchange (ETDEWEB)

    Kahle, Duncan [NASA, Goddard Space Flight Center, Detector Systems Branch, Greenbelt, MD 20771 (United States); Aslam, Shahid, E-mail: shahid.aslam-1@nasa.gov [NASA, Goddard Space Flight Center, Planetary Systems Laboratory, Greenbelt, MD 20771 (United States); Herrero, Federico A.; Waczynski, Augustyn [NASA, Goddard Space Flight Center, Detector Systems Branch, Greenbelt, MD 20771 (United States)

    2016-09-11

    A compact, low-noise and inexpensive preamplifier circuit has been designed and fabricated to optimally readout a common cathode (1×16) channel 4H-SiC Schottky photodiode array for use in ultraviolet experiments. The readout uses an operational amplifier with 10 pF capacitor in the feedback loop in parallel with a low leakage switch for each of the channels. This circuit configuration allows for reiterative sample, integrate and reset. A sampling technique is given to remove Johnson noise, enabling a femtoampere level readout noise performance. Commercial-off-the-shelf acquisition electronics are used to digitize the preamplifier analog signals. The data logging acquisition electronics has a different integration circuit, which allows the bandwidth and gain to be independently adjusted. Using this readout, photoresponse measurements across the array between spectral wavelengths 200 nm and 370 nm are made to establish the array pixels external quantum efficiency, current responsivity and noise equivalent power.

  12. Optimization of the performance of a pixellated germanium Compton camera

    OpenAIRE

    Ghoggali, W.

    2015-01-01

    A planar HPGe Compton camera for nuclear medicine applications that contains 177 pixels of 4 × 4mm2, of which 25 are at the back detector, is being used to image point sources of Cs137, line sources and clinical-like shape distributed sources. Experimental results are obtained to study the e ffects of energy resolution, position sensitivity, and reconstruction algorithms on camera images. Preamplifi ed pulses are digitized for pulse shape analysis using gamma ray tracking GRT4s data acquisiti...

  13. ATLAS Pixel Opto-Electronics

    CERN Document Server

    Arms, K E; Gan, K K; Holder, M; Jackson, P; Johnson, M; Kagan, H; Kass, R; Rahimi, A M; Roggenbuck, A; Rush, C; Schade, P; Smith, S; Ter-Antonian, R; Ziolkowski, M; Zoeller, M M

    2005-01-01

    We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both ASICs in 0.25 micron CMOS technology using enclosed layout transistors and guard rings for increased radiation hardness. We present results of the performance of these chips, including irradiation with 24 GeV protons up to 61 Mrad (2.3 x 10e15 p/cm^2).

  14. Pixel-level continuous-time incremental sigma-delta A/D converter for THz sensors

    Science.gov (United States)

    Khatib, Moustafa; Perenzoni, Matteo

    2016-04-01

    A readout channel based on continuous-time incremental sigma-delta analog-to-digital converter for FET-based terahertz (THz) imaging applications was implemented in a 0.15 μm standard CMOS technology. The designed readout circuit is suitable for implementation in pixel arrays due to its compact size and power consumption. The system-level analysis used to define the modulator parameters and to specify its analog building blocks is presented. The loop filter has been realized by using a Gm-C integrator. Circuit linearization techniques have been implemented to improve the linearity of the transconductor cell and reduce the impact of parasitic capacitances. Moreover, chopper stabilization technique is adopted in the loop filter, significantly reducing the low-frequency flicker noise thereby preserving the Noise Equivalent Power (NEP) of the FET detector within the required specifications of minimum detectable signal. The resulting input referred noise voltage is 87.5 nV/√Hz . The incremental ADC achieves 68-dB peak signal-to-noise-and-distortion-ratio (SNDR), equivalent to 11 bits effective resolution over 1 kHz signal bandwidth at 1 MHz sampling frequency. In order to meet the requirements of large sensor arrays, a first order architecture is realized. This leads to lower area occupancy and power consumption. The readout circuit draws 80 μW of power from a supply voltage of 1.8 V. The channel occupies an area of 90 x 273μm2.

  15. Pixel readout chip for the ATLAS experiment

    CERN Document Server

    Ackers, M; Blanquart, L; Bonzom, V; Comes, G; Fischer, P; Keil, M; Kühl, T; Meuser, S; Delpierre, P A; Treis, J; Raith, B A; Wermes, N

    1999-01-01

    Pixel detectors with a high granularity and a very large number of sensitive elements (cells) are a very recent development used for high precision particle detection. At the Large Hadron Collider LHC at CERN (Geneva) a pixel detector with 1.4*10/sup 8/ individual pixel cells is developed for the ATLAS detector. The concept is a hybrid detector. Consisting of a pixel sensor connected to a pixel electronics chip by bump and flip chip technology in one-to-one cell correspondence. The development and prototype results of the pixel front end chip are presented together with the physical and technical requirements to be met at LHC. Lab measurements are reported. (6 refs).

  16. Advanced pixel architectures for scientific image sensors

    CERN Document Server

    Coath, R; Godbeer, A; Wilson, M; Turchetta, R

    2009-01-01

    We present recent developments from two projects targeting advanced pixel architectures for scientific applications. Results are reported from FORTIS, a sensor demonstrating variants on a 4T pixel architecture. The variants include differences in pixel and diode size, the in-pixel source follower transistor size and the capacitance of the readout node to optimise for low noise and sensitivity to small amounts of charge. Results are also reported from TPAC, a complex pixel architecture with ~160 transistors per pixel. Both sensors were manufactured in the 0.18μm INMAPS process, which includes a special deep p-well layer and fabrication on a high resistivity epitaxial layer for improved charge collection efficiency.

  17. Achieving subpixel resolution with time-correlated transient signals in pixelated CdZnTe gamma-ray sensors using a focused laser beam (Conference Presentation)

    Science.gov (United States)

    Ocampo Giraldo, Luis A.; Bolotnikov, Aleksey E.; Camarda, Giuseppe S.; Cui, Yonggang; De Geronimo, Gianluigi; Gul, Rubi; Fried, Jack; Hossain, Anwar; Unlu, Kenan; Vernon, Emerson; Yang, Ge; James, Ralph B.

    2017-05-01

    High-resolution position-sensitive detectors have been proposed to correct response non-uniformities in Cadmium Zinc Telluride (CZT) crystals by virtually subdividing the detectors area into small voxels and equalizing responses from each voxel. 3D pixelated detectors coupled with multichannel readout electronics are the most advanced type of CZT devices offering many options in signal processing and enhancing detector performance. One recent innovation proposed for pixelated detectors is to use the induced (transient) signals from neighboring pixels to achieve high sub-pixel position resolution while keeping large pixel sizes. The main hurdle in achieving this goal is the relatively low signal induced on the neighboring pixels because of the electrostatic shielding effect caused by the collecting pixel. In addition, to achieve high position sensitivity one should rely on time-correlated transient signals, which means that digitized output signals must be used. We present the results of our studies to measure the amplitude of the pixel signals so that these can be used to measure positions of the interaction points. This is done with the processing of digitized correlated time signals measured from several adjacent pixels taking into account rise-time and charge-sharing effects. In these measurements we used a focused pulsed laser to generate a 10-micron beam at one milliwatt (650-nm wavelength) over the detector surface while the collecting pixel was moved in cardinal directions. The results include measurements that present the benefits of combining conventional pixel geometry with digital pulse processing for the best approach in achieving sub-pixel position resolution with the pixel dimensions of approximately 2 mm. We also present the sub-pixel resolution measurements at comparable energies from various gamma emitting isotopes.

  18. The Effect of Pixel Size on the Accuracy of Orthophoto Production

    Science.gov (United States)

    Kulur, S.; Yildiz, F.; Selcuk, O.; Yildiz, M. A.

    2016-06-01

    In our country, orthophoto products are used by the public and private sectors for engineering services and infrastructure projects, Orthophotos are particularly preferred due to faster and are more economical production according to vector digital photogrammetric production. Today, digital orthophotos provide an expected accuracy for engineering and infrastructure projects. In this study, the accuracy of orthophotos using pixel sizes with different sampling intervals are tested for the expectations of engineering and infrastructure projects.

  19. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Lantzsch, Kerstin; The ATLAS collaboration

    2016-01-01

    Run 2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). In addition the Pixel detector was refurbished with new service quarter panels to recover about 3% of defective modules lost during run 1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning, operation and performance of the 4-layer Pixel Detector will be presented.

  20. Single-pixel 3D imaging with time-based depth resolution

    CERN Document Server

    Sun, Ming-Jie; Gibson, Graham M; Sun, Baoqing; Radwell, Neal; Lamb, Robert; Padgett, Miles J

    2016-01-01

    Time-of-flight three dimensional imaging is an important tool for many applications, such as object recognition and remote sensing. Unlike conventional imaging approach using pixelated detector array, single-pixel imaging based on projected patterns, such as Hadamard patterns, utilises an alternative strategy to acquire information with sampling basis. Here we show a modified single-pixel camera using a pulsed illumination source and a high-speed photodiode, capable of reconstructing 128x128 pixel resolution 3D scenes to an accuracy of ~3 mm at a range of ~5 m. Furthermore, we demonstrate continuous real-time 3D video with a frame-rate up to 12 Hz. The simplicity of the system hardware could enable low-cost 3D imaging devices for precision ranging at wavelengths beyond the visible spectrum.