WorldWideScience

Sample records for area silicon tracking

  1. The GLAST silicon-strip tracking system

    International Nuclear Information System (INIS)

    The GLAST instrument concept is a gamma-ray pair conversion telescope that uses silicon microstrip detector technology to track the electron-positron pairs resulting from gamma-ray conversions in thin lead foils. A cesium iodide calorimeter following the tracker is used to measure the gamma-ray energy. Silicon strip technology is mature and robust, with an excellent heritage in space science and particle physics. It has many characteristics important for optimal performance of a pair conversion telescope, including high efficiency in thin detector planes, low noise, and excellent resolution and two-track separation. The large size of GLAST and high channel count in the tracker puts demands on the readout technology to operate at very low power, yet with sufficiently low noise occupancy to allow self triggering. A prototype system employing custom-designed ASIC's has been built and tested that meets the design goal of approximately 200W per channel power consumption with a noise occupancy of less than one hit per trigger per 10,000 channels. Detailed design of the full-scale tracker is well advanced, with non-flight prototypes built for all components, and a complete 50,000 channel engineering demonstration tower module is currently under construction and will be tested in particle beams in late 1999. The flight-instrument conceptual design is for a 4x4 array of tower modules with an aperture of 2.9 m2 and an effective area of greater than 8000 cm2

  2. The GLAST Silicon-Strip Tracking System

    International Nuclear Information System (INIS)

    The GLAST instrument concept is a gamma-ray pair conversion telescope that uses silicon microstrip detector technology to track the electron-positron pairs resulting from gamma ray conversions in thin lead foils. A cesium iodide calorimeter following the tracker is used to measure the gamma-ray energy. Silicon strip technology is mature and robust, with an excellent heritage in space science and particle physics. It has many characteristics important for optimal performance of a pair conversion telescope, including high efficiency in thin detector planes, low noise, and excellent resolution and two-track separation. The large size of GLAST and high channel count in the tracker puts demands on the readout technology to operate at very low power, yet with sufficiently low noise occupancy to allow self triggering. A prototype system employing custom-designed ASIC's has been built and tested that meets the design goal of approximately 200 (micro)W per channel power consumption with a noise occupancy of less than one hit per trigger per 10,000 channels. Detailed design of the full-scale tracker is well advanced, with non-flight prototypes built for all components, and a complete 50,000 channel engineering demonstration tower module is currently under construction and will be tested in particle beams in late 1999. The flight-instrument conceptual design is for a 4 x 4 array of tower modules with an aperture of 2.9 m2 and an effective area of greater than 8000 cm2

  3. The CDF-II silicon tracking system

    Energy Technology Data Exchange (ETDEWEB)

    F. Palmonari et al.

    2002-01-18

    The CDFII silicon tracking system, SVX, for Run II of the Fermilab Tevatron has up to 8 cylindrical layers with average radii spanning from {approx} (1.5 to 28.7) cm, and lengths ranging from {approx} (90 to 200) cm for a total active-area of {approx} 6 m{sup 2} and {approx} 7.2 x 10{sup 5} readout channels. SVX will improve the CDFII acceptance and efficiency for both B and high-Pt physics dependent upon b-tagging. Along with the description of the SVX we report some alignment survey data from the SVX assembly phase and the actual status of the alignment as it results from the offline data analysis. The problems encountered are also reviewed.

  4. The D/Ø Silicon Track Trigger

    Science.gov (United States)

    Steinbrück, Georg

    2003-09-01

    We describe a trigger preprocessor to be used by the D Ø experiment for selecting events with tracks from the decay of long-lived particles. This Level 2 impact parameter trigger utilizes information from the Silicon Microstrip Tracker to reconstruct tracks with improved spatial and momentum resolutions compared to those obtained by the Level 1 tracking trigger. It is constructed of VME boards with much of the logic existing in programmable processors. A common motherboard provides the I/O infrastructure and three different daughter boards perform the tasks of identifying the roads from the tracking trigger data, finding the clusters in the roads in the silicon detector, and fitting tracks to the clusters. This approach provides flexibility for the design, testing and maintenance phases of the project. The track parameters are provided to the trigger framework in 25 μs. The effective impact parameter resolution for high-momentum tracks is 35 μm, dominated by the size of the Tevatron beam.

  5. Muon tracking system with Silicon Photomultipliers

    International Nuclear Information System (INIS)

    We report the characterisation and performance of a low cost muon tracking system consisting of plastic scintillator bars and Silicon Photomultipliers equipped with a customised front-end electronics based on a fast preamplifier network. This system can be used as a detector test bench for astroparticle physics and for educational and outreach purposes. We investigated the device behaviour in self-trigger and coincidence mode, without using LED and pulse generators, showing that with a relatively simple set up a complete characterisation work can be carried out. A high definition oscilloscope, which can easily be found in many university physics or engineering departments, has been used for triggering and data acquisition. Its capabilities have been exploited to discriminate real particles from the background

  6. Muon tracking system with Silicon Photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Arneodo, F.; Benabderrahmane, M.L.; Dahal, S. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Di Giovanni, A., E-mail: adriano.digiovanni@nyu.edu [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Pazos Clemens, L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Candela, A.; D' Incecco, M.; Sablone, D. [Gran Sasso National Laboratory of INFN, Assergi (Italy); Franchi, G. [AGE Scientific Srl, Capezzano Pianore (Italy)

    2015-11-01

    We report the characterisation and performance of a low cost muon tracking system consisting of plastic scintillator bars and Silicon Photomultipliers equipped with a customised front-end electronics based on a fast preamplifier network. This system can be used as a detector test bench for astroparticle physics and for educational and outreach purposes. We investigated the device behaviour in self-trigger and coincidence mode, without using LED and pulse generators, showing that with a relatively simple set up a complete characterisation work can be carried out. A high definition oscilloscope, which can easily be found in many university physics or engineering departments, has been used for triggering and data acquisition. Its capabilities have been exploited to discriminate real particles from the background.

  7. ATLAS' inner silicon tracker on track for completion

    CERN Multimedia

    2005-01-01

    Last week, the team working at the SR1 facility on the inner detector of the ATLAS experiment reached a project milestone after the delivery of the last Semi-conductor Tracker (SCT) barrel to CERN. The third barrel before its insertion into the support structure.The insertion of a completed barrel to its support structure is one of the highlights of the assembly and test sequence of the SCT in SR1. The inner detector will eventually sit in the 2 teslas magnetic field of the ATLAS solenoid, tracking charged particles from proton-proton collisions at the centre of ATLAS. The particles will be measured by a pixel detector (consisting of 3 pixel layers), an SCT (4 silicon strip layers) and a transition radiation tracker (TRT) (consisting of more than 52,000 straw tubes - see Bulletin 14/2005). The SCT has a silicon surface area of 61m2 with about 6 million operational channels so that all tracks can be identified and precisely measured. During 2004 a team of physicists, engineers, and technicians from several...

  8. Silicon tracking detectors in high-energy physics

    International Nuclear Information System (INIS)

    Since the fifties, semiconductors have been used as energy spectrometers, mainly in unsegmented ways. With the planar technique of processing silicon sensors in unprecedented precession, strip-like segmentation has allowed precise tracking and even vertexing, culminating in the early eighties with NA11 in the tagging of heavy flavor quarks - here the c-quark. With the later miniaturization of electronics, dense detector application was made possible, and large-scale systems were established in the heart of all LEP detectors, permitting vertexing in barrel-like detectors. At the time of LEP and the TEVATRON, tasks were still bifurcated. Small silicon detectors (up to three layers) did the vertexing and further out, gaseous detectors (e.g., drift chambers or time-projection chambers) with larger lever arms did the tracking. In RUN II of the CDF detector, larger silicon tracking devices, still complemented by a huge drift chamber, began to use a stand-alone tracking. At the LHC, ATLAS and CMS bifurcate in a slightly different way. Silicon pixel detectors are responsible for the vertexing, and large volume silicon strip detectors (up to 14 layers) are the main tracking devices. Silicon tracking systems are a fundamental part of modern multipurpose high-energy physics experiments. Despite the vertexing and thus the heavy quark tagging, silicon tracking detectors in combination with a strong B-field deliver the most accurate momentum measurement, and for a large range, also the best energy measurement. In this paper, the functionality of pixel and strip sensors will be introduced, and historical examples will be given to highlight the different implementations of the past 30 years.

  9. Magnesium, Silicon and Calcium Isotopes in Central European Tektites — Implications for High-Temperature Processes and Tracking Their Sources with the Ries Area Sediments

    Czech Academy of Sciences Publication Activity Database

    Magna, T.; Farkaš, J.; Rodovská, Z.; Trubač, J.; Georg, R. B.; Holmden, C.; Žák, Karel

    Houston : Lunar and Planetary Institute, 2015. [Lunar and Planetary Science Conference /46./. 16.03.2015-20.03.2015, Woodlands] R&D Projects: GA ČR GA13-22351S Institutional support: RVO:67985831 Keywords : tektites * magnesium * silicon * calcium * isotopes Subject RIV: DB - Geology ; Mineralogy http://www.hou.usra.edu/meetings/lpsc2015/pdf/2207.pdf

  10. Overview of the Silicon Tracking System for the CBM experiment

    Science.gov (United States)

    Larionov, Pavel; CBM Collaboration

    2015-04-01

    The Compressed Baryonic Matter (CBM) experiment will explore the QCD phase diagram in the region of high net baryonic densities and moderate temperatures. CBM will start it's physics program at the SIS-100 and later at the SIS-300 synchrothrons which will deliver beams for heavy ion collisions at energies up to 45 AGeV with hit rates up to 10 MHz.The Silicon Tracking System (STS) is the core tracking detector of the experiment. It will be used for the reconstruction of the tracks of charged particles and determination of their momenta. For this task eight tracking stations constructed with double-sided sililconmicro-strip sensors will be accomodated downstream the target inside the superconducting magnet. The required momentum resolution for particles with momenta above 1 GeV/c is of the order of Δp/p = 1%. To aim this, the material budget should be reduced to the level of 1% X0. The STS will provide track reconstruction efficiency for fast primary tracks on the level of 95%and higher. In this paper, the detector concept is summarized along with the detector components and simulation of the system's performance. Also, the quality assurance tests of the silicon sensors in which the author is involved in, are presented.

  11. Silicon-based tracking system: Mechanical engineering and design

    International Nuclear Information System (INIS)

    The Silicon Tracking System (STS) is composed of silicon strip detectors arranged by both in a cylindrical array and an array of flat panels about the interaction region. The cylindrical array is denoted the central region and the flat panel arrays, which are normal to the beam axis, we denoted the forward regions. The overall length of the silicon array is 5.16 m and the maximum diameter is 0.93 m. The Silicon Tracking System Conceptual Design Report, should be consulted for the body of analysis performed to quantify the present design concept. For the STS to achieve its physics goals, the mechanical structures and services must support 17 m2 of silicon detectors and stabilize their positions to within 5 μm, uniformly cool the detector the system to O degrees C and at the same time potentially remove up to 13 kW of waste heat generated by the detector electronics, provide up to 3400 A of current to supply the 6.5 million electronics channels, and supply of control and data transmission lines for those channels. These objectives must be achieved in a high ionizing radiation environment, using virtually no structural mass and only low-Z materials. The system must be maintainable during its 10 year operating life

  12. Automated quality assurance for silicon microstrip sensors of the CBM Silicon Tracking System

    International Nuclear Information System (INIS)

    The Silicon Tracking System (STS) is the main tracking detector of the upcoming fixed-target Compressed Baryonic Matter (CBM) experiment which aims to explore the phase diagram of the strongly interacting matter in a region of high net baryonic densities and moderate temperatures. The STS will be used for the reconstruction of tracks of charged particles and determination of their momenta. The system comprises 8 tracking stations located 30 cm downstream the target and will be mounted with 300 μm thick double-sided silicon microstrip sensors in three different sizes. In this paper, the Quality Assurance (QA) procedures for the STS sensors are overviewed highlighting the automated QA testing procedure for a single strip defect identification

  13. Automated quality assurance for silicon microstrip sensors of the CBM Silicon Tracking System

    Science.gov (United States)

    Larionov, P.

    2016-01-01

    The Silicon Tracking System (STS) is the main tracking detector of the upcoming fixed-target Compressed Baryonic Matter (CBM) experiment which aims to explore the phase diagram of the strongly interacting matter in a region of high net baryonic densities and moderate temperatures. The STS will be used for the reconstruction of tracks of charged particles and determination of their momenta. The system comprises 8 tracking stations located 30 cm downstream the target and will be mounted with 300 μm thick double-sided silicon microstrip sensors in three different sizes. In this paper, the Quality Assurance (QA) procedures for the STS sensors are overviewed highlighting the automated QA testing procedure for a single strip defect identification.

  14. Forward physics at PHENIX with precision silicon tracking

    Science.gov (United States)

    Durham, J. Matthew

    2014-03-01

    The PHENIX experiment at RHIC has developed and installed a new silicon detector, the Forward Silicon Vertex Tracker (FVTX), to provide precise tracking at forward and backward rapidity (1 . 2 strip sensors with a 75 micron pitch in the radial direction, and is located in front of the existing PHENIX muon arms. By determining muon tracks with high precision before any interactions occur in the hadron absorber, the FVTX will enhance the mass resolution of dimuon resonance measurements as well as allow separation of decay muons from charm and bottom hadrons produced in heavy ion collisions. In this talk, the design and capabilities of the FVTX will be discussed, along with the analysis status of FVTX data.

  15. Experimental Investigation on Electrical Tracking of Epoxy Resin Compound with Silicon Rubber%Experimental Investigation on Electrical Tracking of Epoxy Resin Compound with Silicon Rubber

    Institute of Scientific and Technical Information of China (English)

    Abdul Syakur; Hamzah Berahim; Tumiran; Rochmadi

    2011-01-01

    The use of polymer materials as electrical insulators on transmission and distribution lines has been increas- ing such,as epoxy resin. Several advantages of using epoxy resin as an insulating material are its low density, better dielectric properties, and epoxy resin has higher volume resistivity than that of the glass and porcelain. However, ep- oxy resin has some disadvantages when it is used in tropical areas concerning with the humidity, high ultraviolet radia- tion, acid rain and effects of contaminants. Consequently, insulator surface will be easily damaged due to electrical tracking, which is indicated by the surface tracking. In this paper, the surface tracking on epoxy resin compound with silicon rubber has been investigated. The test was done based on the method of Inclined--Planed Tracking (IPT) IEC 587.. 1984 with NH4 C1 as contaminant. The test materials used were epoxy resins based on Diglycidyl Ether of Bisphenol A (DGEBA) and Methaphenylene Diamine (MPDA) compound with silicon rubber ( SiR ) with the dimensions of 50 mm×120 mm and the thickness of 6 mm. The flow rate of contaminant was 0.3 mL/min. The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes. The experimental results show that the contact angle of hydrophobic was affected by compound of silicon rubber. The surface tracking, time to tracking and discharge current were affected by applied voltage, contamination and contact angle. By using micro--cameras, the surface damage was detected. The severest damaged sample surface on a sample had small contact angle. On the other hand, samples with the greatest contact angle needed longer time to have surface damage in the surface discharge. This shows that it is more difficult for large contact angle samples or more hydrophobic to have surface discharge. Epoxy resin compound with silicon rubber has contact angle of hydrophobic greater than epoxy resin without silicon rubber.

  16. Gamma Large Area Silicon Telescope (GLAST)

    International Nuclear Information System (INIS)

    The recent discoveries and excitement generated by EGRET have prompted an investigation into modern technologies ultimately leading to the next generation space-based gamma ray telescope. The goal is to design a detector that will increase the data acquisition rate by almost two orders of magnitude beyond EGRET, while at the same time improving on the angular resolution, the energy measurement of reconstructed gamma rays, and the triggering capability of the instrument. The GLAST proposal is based on the assertion that silicon particle detectors are the technology of choice for space application: no consumables, no gas volume, robust (versus fragile), long lived, and self triggering. The GLAST detector is roughly modeled after EGRET in that a tracking module precedes a calorimeter. The GLAST Tracker has planes of thin radiatior interspersed with planes of crossed-strip (x,y) 300-μm-pitch silicon detectors to measure the coordinates of converted electron-positron pairs. The gap between the layers (∼5 cm) provides a lever arm in track fitting resulting in an angular resolution of 0.1 degree at high energy (the low energy angular resolution at 100 MeV would be about 2 degree, limited by multiple scattering). A possible GLAST calorimeter is made of a mosaic of Csl crystals of order 10 r.l. in depth, with silicon photodiodes readout. The increased depth of the GLAST calorimeter over EGRET's extends the energy range to about 300 GeV

  17. Gamma Large Area Silicon Telescope (GLAST)

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, G.L.

    1993-11-01

    The recent discoveries and excitement generated by EGRET have prompted an investigation into modern technologies ultimately leading to the next generation space-based gamma ray telescope. The goal is to design a detector that will increase the data acquisition rate by almost two orders of magnitude beyond EGRET, while at the same time improving on the angular resolution, the energy measurement of reconstructed gamma rays, and the triggering capability of the instrument. The GLAST proposal is based on the assertion that silicon particle detectors are the technology of choice for space application: no consumables, no gas volume, robust (versus fragile), long lived, and self triggering. The GLAST detector is roughly modeled after EGRET in that a tracking module precedes a calorimeter. The GLAST Tracker has planes of thin radiatior interspersed with planes of crossed-strip (x,y) 300-{mu}m-pitch silicon detectors to measure the coordinates of converted electron-positron pairs. The gap between the layers ({approximately}5 cm) provides a lever arm in track fitting resulting in an angular resolution of 0.1{degree} at high energy (the low energy angular resolution at 100 MeV would be about 2{degree}, limited by multiple scattering). A possible GLAST calorimeter is made of a mosaic of Csl crystals of order 10 r.l. in depth, with silicon photodiodes readout. The increased depth of the GLAST calorimeter over EGRET`s extends the energy range to about 300 GeV.

  18. Preliminary thoughts on the data acquisition for the next generation of silicon tracking systems

    Indian Academy of Sciences (India)

    J F Genat; A Savoy-Navarro

    2007-12-01

    Preliminary thoughts about the data acquisition system to be developed for the next generation of large area silicon tracker are presented in this paper. This paper describes the set of data delivered by these tracking systems, and the various stages of processing and data flow transmission from the front-end chip sitting on the detector to the latest stage in the data processing. How to best profit from the status of the art technologies is a major goal.

  19. Local alignment of the BABAR Silicon Vertex Tracking detector

    International Nuclear Information System (INIS)

    The BABAR Silicon Vertex Tracker (SVT) is a five-layer double-sided silicon detector designed to provide precise measurements of the position and direction of primary tracks, and to fully reconstruct low-momentum tracks produced in e+e- collisions at the PEP-II asymmetric collider at Stanford Linear Accelerator Center. This paper describes the design, implementation, performance, and validation of the local alignment procedure used to determine the relative positions and orientations of the 340 SVT wafers. This procedure uses a tuned mix of in situ experimental data and complementary lab-bench measurements to control systematic distortions. Wafer positions and orientations are determined by minimizing a χ2 computed using these data for each wafer individually, iterating to account for between-wafer correlations. A correction for aplanar distortions of the silicon wafers is measured and applied. The net effect of residual misalignments on relevant physical variables is evaluated in special control samples. The BABAR data-sample collected between November 1999 and April 2008 is used in the study of the SVT stability.

  20. Calibration and alignment of the CMS silicon tracking detector

    Energy Technology Data Exchange (ETDEWEB)

    Stoye, M.

    2007-07-15

    The Large Hadron Collider (LHC) will dominate the high energy physics program in the coming decade. The discovery of the standard model Higgs boson and the discovery of super-symmetric particles are within the reach at the energy scale explored by the LHC. However, the high luminosity and the high energy of the colliding protons lead to challenging demands on the detectors. The hostile radiation environment requires irradiation hard detectors, where the innermost subdetectors, consisting of silicon modules, are most affected. This thesis is devoted to the calibration and alignment of the silicon tracking detector. Electron test beam data, taken at DESY, have been used to investigate the performance of detector modules which previously were irradiated with protons up to a dose expected after 10 years of operation. The irradiated sensors turned out to be still better than required. The performance of the inner tracking systems will be dominated by the degree to which the positions of the sensors can be determined. Only a track based alignment procedure can reach the required precision. Such an alignment procedure is a major challenge given that about 50000 geometry constants need to be measured. Making use of the novel {chi}{sup 2} minimization program Millepede II an alignment strategy has been developed in which all detector components are aligned simultaneously, as many sources of information as possible are used, and all correlations between the position parameters of the detectors are taken into account. Utilizing simulated data, a proof of concept of the alignment strategy is shown. (orig.)

  1. Calibration and alignment of the CMS silicon tracking detector

    International Nuclear Information System (INIS)

    The Large Hadron Collider (LHC) will dominate the high energy physics program in the coming decade. The discovery of the standard model Higgs boson and the discovery of super-symmetric particles are within the reach at the energy scale explored by the LHC. However, the high luminosity and the high energy of the colliding protons lead to challenging demands on the detectors. The hostile radiation environment requires irradiation hard detectors, where the innermost subdetectors, consisting of silicon modules, are most affected. This thesis is devoted to the calibration and alignment of the silicon tracking detector. Electron test beam data, taken at DESY, have been used to investigate the performance of detector modules which previously were irradiated with protons up to a dose expected after 10 years of operation. The irradiated sensors turned out to be still better than required. The performance of the inner tracking systems will be dominated by the degree to which the positions of the sensors can be determined. Only a track based alignment procedure can reach the required precision. Such an alignment procedure is a major challenge given that about 50000 geometry constants need to be measured. Making use of the novel χ2 minimization program Millepede II an alignment strategy has been developed in which all detector components are aligned simultaneously, as many sources of information as possible are used, and all correlations between the position parameters of the detectors are taken into account. Utilizing simulated data, a proof of concept of the alignment strategy is shown. (orig.)

  2. Superconducting Super Collider silicon tracking subsystem research and development

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.O.; Thompson, T.C.; Ziock, H.J. (Los Alamos National Lab., NM (USA)); Gamble, M.T. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Materials Science and Engineering)

    1990-12-01

    The Alamos National Laboratory Mechanical Engineering and Electronics Division has been investigating silicon-based elementary particle tracking device technology as part of the Superconducting Super Collider-sponsored silicon subsystem collaboration. Structural, materials, and thermal issues have been addressed. This paper explores detector structural integrity and stability, including detailed finite element models of the silicon wafer support and predictive methods used in designing with advanced composite materials. The current design comprises a magnesium metal matrix composite (MMC) truss space frame to provide a sparse support structure for the complex array of silicon detectors. This design satisfies the 25-{mu}m structural stability requirement in a 10-Mrad radiation environment. This stability is achieved without exceeding the stringent particle interaction constraints set at 2.5% of a radiation length. Materials studies have considered thermal expansion, elastic modulus, resistance to radiation and chemicals, and manufacturability of numerous candidate materials. Based on optimization of these parameters, the MMC space frame will possess a coefficient of thermal expansion (CTE) near zero to avoid thermally induced distortions, whereas the cooling rings, which support the silicon detectors and heat pipe network, will probably be constructed of a graphite/epoxy composite whose CTE is engineered to match that of silicon. Results from radiation, chemical, and static loading tests are compared with analytical predictions and discussed. Electronic thermal loading and its efficient dissipation using heat pipe cooling technology are discussed. Calculations and preliminary designs for a sprayed-on graphite wick structure are presented. A hydrocarbon such as butane appears to be a superior choice of heat pipe working fluid based on cooling, handling, and safety criteria.

  3. Superconducting Super Collider silicon tracking subsystem research and development

    International Nuclear Information System (INIS)

    The Alamos National Laboratory Mechanical Engineering and Electronics Division has been investigating silicon-based elementary particle tracking device technology as part of the Superconducting Super Collider-sponsored silicon subsystem collaboration. Structural, materials, and thermal issues have been addressed. This paper explores detector structural integrity and stability, including detailed finite element models of the silicon wafer support and predictive methods used in designing with advanced composite materials. The current design comprises a magnesium metal matrix composite (MMC) truss space frame to provide a sparse support structure for the complex array of silicon detectors. This design satisfies the 25-μm structural stability requirement in a 10-Mrad radiation environment. This stability is achieved without exceeding the stringent particle interaction constraints set at 2.5% of a radiation length. Materials studies have considered thermal expansion, elastic modulus, resistance to radiation and chemicals, and manufacturability of numerous candidate materials. Based on optimization of these parameters, the MMC space frame will possess a coefficient of thermal expansion (CTE) near zero to avoid thermally induced distortions, whereas the cooling rings, which support the silicon detectors and heat pipe network, will probably be constructed of a graphite/epoxy composite whose CTE is engineered to match that of silicon. Results from radiation, chemical, and static loading tests are compared with analytical predictions and discussed. Electronic thermal loading and its efficient dissipation using heat pipe cooling technology are discussed. Calculations and preliminary designs for a sprayed-on graphite wick structure are presented. A hydrocarbon such as butane appears to be a superior choice of heat pipe working fluid based on cooling, handling, and safety criteria

  4. Fixed Scan Area Tracking with Track Splitting Filtering Algorithm

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar; Ahmed, Zaki

    2006-01-01

    The paper presents a simulation study by tracking multiple objects in a fixed window using a non deterministic scenario for the performance evaluation of track splitting algorithm on a digital signal processor.  Much of the previous work [1] was done on specific (deterministic) scenarios. One of...... the reasons for considering the specific scenarios, which were normally crossing objects, was to test the efficiency of the track splitting algorithm for different situations. However this approach only gives a measure of performance for a specific, possibly unrealistic, scenario and it was felt...... appropriate to develop procedures that would enable a more general performance assessment. Therefore, a non-deterministic scenario is adopted, which basically provide a more appropriate approach for the evaluation of a tracking system based on track splitting filter algorithm.  The objects are generated...

  5. Large area cylindrical silicon drift detector

    International Nuclear Information System (INIS)

    An advanced silicon drift detector, a large area cylindrical drift detector, was designed, produced, tested and installed in the NA45 experiment. The active area of the detector is practically the total area of a 3 inch diameter wafer. Signal electrons created in the silicon detector by fast charged particles drift radially outside toward an array of 360 anodes located on the periphery of the detector. The drift time measures the radial coordinate of the particle's intersection; the charge sharing between anodes measures the azimuthal coordinate. The detector provides unambiguous pairs of r,φ coordinates for events with multiplicities up to several hundred. Its use in the experiment aims at a position resolution of 20 μm (rms) in each direction giving about 2 · 106 two-dimensional elements. There is a small hole in the center of the detector to allow the passage of the noninteracting particle beam. The longest drift distance is about 3 cm. The nominal value of the drift field is 500 V/cm resulting in a maximum drift time of 4 μs

  6. Large area cylindrical silicon drift detector

    International Nuclear Information System (INIS)

    This paper reports on an advanced silicone drift detector, a large area cylindrical drift detector that was designed, produced, tested and installed in the Na45 experiment. The active area of the detector is practically the total area of a 3 inch diameter wafer. Signal electrons created in the silicon detector by fast charged particles drift radially outside toward an array of 360 anodes located on the periphery of the detector. The drift time measures the radial coordinate of the particle's intersection; the charge sharing between anodes measures the azimuthal coordinate. The detector provides unambiguous pairs of r, φ coordinates for events with multiplicities up to several hundred. Its use in the experiment aims at a position resolution of 20 μm (rms) in each direction giving about 2 · 106 two-dimensional elements. There is a small hole in the center of the detector to allow the passage of the noninteracting particle beam. The longest drift distance is about 3 cm. The nominal value of the drift field is 500 V/cm resulting in a maximum drift time of 4 μs

  7. The silicon tracking system of the CBM experiment at fair

    International Nuclear Information System (INIS)

    The Compressed Baryonic Matter (CBM) experiment [1] will study the properties of nuclear matter by exploration of the QCD phase diagram in the region of high baryonic densities and moderate temperatures. The collision system will be created with beams of ultra-relativistic heavy-ions of up to 45A GeV energy. After reaching a certain critical combination of density and temperature, the hadronic matter is predicted to undergo a phase transition to a deconfined state - the quark-gluon plasma. A precise study of the phase boundary, properties of the deconfined matter and in-medium modification of hadron properties will be studied with a number of hadronic, leptonic and photonic observables including rare probes like low-mass vector mesons and open charm. Double-sided silicon microstrip detectors of 300 μm thickness and 50 μm strip pitch have been characterized in the laboratory and used for the construction of a prototype beam tracking telescope. Three tracking stations have been operated at GSI in a 2 GeV proton beam. The readout chain comprised the self-triggering n-XYTER front-end chip, CBM prototype readout controllers and the DABC data acquisition system. The performance of the sensors, the front-end electronics and test system are presented in the following paragraphs.

  8. A Tracking Fiber Detector based on Silicon Photomultipliers for the Kaos Spectrometer

    CERN Document Server

    Achenbach, P; Majos, S Sánchez

    2011-01-01

    A tracking detector based on two meters long scintillating fibers read out by silicon photomultipliers (SiPM) is being developed for the Kaos spectrometer at the Mainz Microtron MAMI. Results from a prototype setup using 2 mm square fibers and large area SiPM readout are presented. The detection efficiency of such a combination was measured to be between 83 and 100% depending on the threshold on the SiPM amplitude. A Monte Carlo simulation based on a physical model was employed in order to extract the photon detection efficiency of the SiPM devices.

  9. Recent results from beam tests of large area silicon drift detectors

    International Nuclear Information System (INIS)

    Silicon drift detectors with an active area of 7.0 x 7.5 cm2 will equip the two middle layers of the Inner Tracking System of the ALICE experiment. The performance of several prototypes was studied during beam tests carried out at the CERN SPS facility. The results of the beam test data analysis are discussed in this paper

  10. The Silicon Tracking System of the CBM Experiment at FAIR

    Science.gov (United States)

    Heuser, Johann M.

    The Compressed Baryonic Matter (CBM) experiment at FAIR will conduct a systematic research program to explore the phase diagram of strongly interacting matter at highest net baryon densities and moderate temperatures. These conditions are to be created in collisions of heavy-ion beams with nuclear targets in the projectile beam energy range of 2 to 45 GeV/nucleon, initially coming from the SIS 100 synchrotron (up to 14 GeV/nucleon) and in a next step from SIS 300 enabling studies at the highest net baryon densities. Collision rates up to 107 per second are required to produce very rare probes with unprecedented statistics in this energy range. Their signatures are complex. These conditions call for detector systems designed to meet the extreme requirements in terms of rate capability, momentum and spatial resolution, and a novel data acquisition and trigger concept which is not limited by latency but by throughput. In the paper we describe the concept and development status of CBM's central detector, the Silicon Tracking System (STS). The detector realizes a large, highly granular and redundant detector system with fast read-out, and lays specific emphasis on low material budget in its physics aperture to achieve for charged particle tracks a momentum resolution of δp/p ≈ 1% at p > 1 GeV/c, at >95% track reconstruction efficiency. The detector employs 1220 highly segmented double-sided silicon micro-strip sensors of 300 µm thickness, mounted into 896 modular structures of various types that are aggregated on 106 low-mass carbon fiber ladders of different sizes that build up the tracking stations. The read-out electronics with its supply and cooling infrastructure is arranged at the periphery of the ladders, and provides a total channel count of 1.8 million. The signal transmission from the silicon sensors to the electronics is realized through ultra-thin multi-line aluminum-polyimide cables of up to half a meter length. The electronics generates a free

  11. Studies for the silicon tracking system of the International Large Detector at the International Linear Collider

    International Nuclear Information System (INIS)

    The International Large Detector (ILD) is one of the proposed detector concepts for the future International Linear Collider (ILC), which will extend and complement the physics program of the Large Hadron Collider (LHC). One of the perceived priorities of an ILC detector is the reconstruction of charged particle momenta with a precision of sigma(1/pt) =2·10-5 (GeV/c)-1. The ILD meets this requirement with a central tracking system consisting of a TPC combined with silicon strip detectors. In the barrel region, the silicon tracking system is composed of three double layers of silicon strip detectors. Two of these layers, located between vertex detector and TPC, form the Silicon Internal Tracker (SIT) and the third layer surrounds the TPC, the Silicon External Tracker (SET). After a short description of the ILC and its possible physics program, the ILD, its tracking system and especially silicon strip sensors are examined in more detail. Based on simulations, presented in this thesis, it could be verified that the high demands on the resolution of charged particle momenta can only be satisfied with the inclusion of precise measured space points just outside the TPC volume. These simulations led to the inclusion of the SET into the ILD baseline design. It was understood, that the resolution of the SET along the TPC must be in the order of 50μm and that its resolution in r-phi must be below 10μm. Two different silicon strip sensors, a multi-geometry and a big area sensor, were designed with the purpose to provide a deeper insight into the definition of the ILD tracking system. These two sensors could be implemented on one silicon wafer which was produced by Hamamatsu Photonics, Japan. Each of the multi-geometry sensors contains 256 readout strips arranged in 16 zones with different strip geometries and a readout pitch of 50μm, which is the lower limit for reliable mass production of silicon strip detectors, as needed for large scale detector systems. These sensors

  12. Development of a Test System for the Quality Assurance of Silicon Microstrip Detectors for the Inner Tracking System of the CMS Experiment

    CERN Document Server

    Axer, Markus

    2003-01-01

    The inner tracking system of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) which is being built at the European Laboratory for Particle Physics CERN (Geneva, Switzerland) will be equipped with two different technologies of silicon detectors. While the innermost tracker will be composed of silicon pixel detectors, silicon microstrip detectors are envisaged for the outer tracker architecture. The silicon microstrip tracker will house about 15,000 single detector modules each composed of a set of silicon sensors, the readout electronics (front end hybrid), and a support frame. It will provide a total active area of 198 m2 and ten million analogue channels read out at the collider frequency of 40 MHz. This large number of modules to be produced and integrated into the tracking system is an unprecedented challenge involving industrial companies and various research institutes from many different countries. This thesis deals with the physics of silicon sensors and the preparation of ...

  13. New developments of the R & D silicon tracking for linear collider on silicon trackers

    Indian Academy of Sciences (India)

    A Savoy-Navarro; on behalf of the SiLC R&D Collaboration

    2007-12-01

    The status of the R & D activity achieved so far within the SiLC (silicon tracking for the linear collider) collaboration is reported here. It includes the following items: present status of the collaboration, new developments on sensors, on mechanics (new directions for module construction, large support structure, cooling, and alignment and integration issues), new lab test bench results on electronics and sensors. The perspectives over a period of four years are presented with a detailed test beam schedule and the roadmap including the construction of new mechanical prototypes equipped with front end and readout chips in deep sub-micron CMOS technology are discussed. Combined tests with other sub-detectors are finally addressed. This test beam program is inserted in the framework of the EUDET European project.

  14. Silicon pad detectors for a simple tracking system and multiplicity detectors creation

    International Nuclear Information System (INIS)

    Silicon pad detectors are working at room temperatures, what is very convenient for creation of simple tracking system and multiplicity detectors. Silicon pad detectors are studied to create a compact detecting systems for active beam collimation and for gamma-radiation multiplicity measurements. The registration efficiency and spectral distributions of gamma-radiation and electrons were studied using isotope radiation sources. The silicon pad detectors were designed at NSC 'KIPT'

  15. Systematic characterization and quality assurance of silicon micro-strip sensors for the Silicon Tracking System of the CBM experiment

    International Nuclear Information System (INIS)

    The Silicon Tracking System (STS) is the central detector of the Compressed Baryonic Matter (CBM) experiment at future Facility for Anti-proton and Ion Research (FAIR) at Darmstadt. The task of the STS is to reconstruct trajectories of charged particles originating at relatively high multiplicities from the high rate beam-target interactions. The tracker comprises of 300 μm thick silicon double-sided micro-strip sensors. These sensors should be radiation hard in order to reconstruct charged particles up to a maximum radiation dose of 1 × 1014neqcm−2. Systematic characterization allows us to investigate the sensor response and perform quality assurance (QA) tests. In this paper, systematic characterization of prototype double-sided silicon micro-strip sensors will be discussed. This procedure includes visual, passive electrical, and radiation hardness test. Presented results include tests on three different prototypes of silicon micro-strip sensors

  16. Large-area silicon detection in hadronic sampling calorimetry

    International Nuclear Information System (INIS)

    The usage of a maximum size silicon wafer area was optimized by using a geometry with two trapezoidal detectors, each of 28 cm2. In order to enable the use of silicon detectors for hadron calorimeters a mosaic module consisting of 18 trapezoidal detectors was developed and assembled. Laser cutting technique was employed to minimize the dead area of the mosaic. In the performed investigations no physical deterioration was observed. (orig.)

  17. Front-end readout electronics considerations for Silicon Tracking System and Muon Chamber

    International Nuclear Information System (INIS)

    Silicon Tracking System (STS) and Muon Chamber (MUCH) are components of the Compressed Baryonic Matter (CBM) experiment at FAIR, Germany. STS will be built from 8 detector stations located in the aperture of the magnet. Each station will be built from double-sided silicon strip detectors and connected via kapton microcables to the readout electronics at the perimeter of each station. The challenging physics program of the CBM experiment requires from the detector systems very high performance. Design of the readout ASIC requires finding an optimal solution for interaction time and input charge measurements in the presence of: tight area (channel pitch: 58 μ m), noise (< 1000 e- rms), power (< 10 mW/channel), radiation hardness and speed requirements (average hit rate: 250 khit/s/channel). This paper presents the front-end electronics' analysis towards prototype STS and MUCH readout ASIC implementation in the UMC 180 nm CMOS process and in-system performance with the emphasis on preferable detector and kapton microcable parameters and input amplifiers' architecture and design

  18. Test of prototypes of the ALICE silicon pixel detector in a multi-track environment

    Science.gov (United States)

    Pulvirenti, A.; Anelli, G.; Antinori, F.; Badalà, A.; Bruno, G. E.; Burns, M.; Cali, I. A.; Campbell, M.; Caselle, M.; Ceresa, S.; Chocula, P.; Cinausero, M.; Conrad, J.; Dima, R.; Elia, D.; Fabris, D.; Fini, R. A.; Fioretto, E.; Kapusta, S.; Kluge, A.; Krivda, M.; Lenti, V.; Librizzi, F.; Lunardon, M.; Manzari, V.; Morel, M.; Moretto, S.; Osmic, F.; Pappalardo, G. S.; Paticchio, V.; Pepato, A.; Prete, G.; Riedler, P.; Riggi, F.; Sandor, L.; Santoro, R.; Scarlassara, F.; Segato, G.; Soramel, F.; Stefanini, G.; Torcato de Matos, C.; Turrisi, R.; Vannucci, L.; Viesti, G.; Virgili, T.

    2006-09-01

    The silicon pixel detector (SPD) comprises the two innermost layers of the ALICE Inner Tracking System (ITS). It is instrumented with arrays of hybrid pixels made out of 150 μm thick ASICs, each containing 8192 readout cells, bump bonded to 200 μm thick silicon sensors. The dimensions of the pixel cells are 50 μm ( rϕ)×425 μm ( z). Prototype assemblies have been tested in high-energy particle beams at the CERN SPS. The results of measurements in a multi-track environment, from interactions of an In beam at 158 AGeV on a Pb target, are reported.

  19. Momentum resolution improvement technique for silicon tracking detectors using d E/d x

    Science.gov (United States)

    Paganis, Stathes D.; Tang, Jaw-Luen

    2001-08-01

    A technique for improving the momentum resolution for low momentum charged particles in few layer silicon based trackers is presented. The particle momenta are determined from the measured Landau d E/d x distribution and the Bethe-Bloch formula in the 1/ β2 region. It is shown that a factor of two improvement of the momentum determination is achieved as compared to standard track fitting methods. This improvement is important in large scale heavy ion experiments which cover the low transverse momentum spectra using stand-alone silicon tracking devices with a few planes like the ones used in STAR at RHIC and ALICE at LHC.

  20. Momentum Resolution Improvement Technique for Silicon Tracking Detectors using dE/dx

    CERN Document Server

    Paganis, S D; Tang, Jaw-Luen

    2001-01-01

    A technique for improving the momentum resolution for low momentum charged particles in few layer silicon based trackers is presented. The particle momenta are determined from the measured Landau dE/dx distribution and the Bethe-Bloch formula in the 1/beta^2 region. It is shown that a factor of two improvement of the momentum determination is achieved as compared to standard track fitting methods. This improvement is important in large scale heavy ion experiments which cover the low transverse momentum spectra using stand-alone silicon tracking devices with a few planes like the ones used in STAR at RHIC and ALICE at LHC.

  1. Characterization of ion track morphology formed by swift heavy ion irradiation in silicon oxynitride films

    Directory of Open Access Journals (Sweden)

    Mota–Santiago P.

    2015-01-01

    Full Text Available Amorphous silicon oxynitride (SiOxNy possess interesting optical and mechanical properties. Here, we present direct evidence for the formation of ion tracks in 1 µm thick silicon oxynitride of different stoichiometries. The tracks were created by irradiation with 185 MeV Au13+ ions. The samples were studied using spectral reflectometry and Rutherford backscattering spectrometry (RBS, with the track morphology characterised by means of small angle X–ray scattering (SAXS. The radial density of the ion tracks resembles a core–shell structure with a typical radius of ~ 1.8 + 2.4 nm in the case of Si3N4 and 2.3 + 3.2 nm for SiO2.

  2. Quality assurance of double-sided silicon strip sensors for silicon tracking system in the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Silicon Tracking System (STS) is the central tracking detector of Compressed Baryonic Matter (CBM) experiment that aims to explore the QCD phase diagram in the region of high net baryonic densities and moderate temperatures. STS consists of 8 tracking layers of double-sided silicon strip sensors with self-triggered read-out system. The challenge is to cope with high hit rates up to 10 MHz/cm2, high tracking density, high radiation load up to 1 x 1014 neq/cm2 and high momentum resolution for the physics case. Hence, the Quality Assurance (QA) procedures become important in the process of building up modules and stations of these sensors. This presentation describes the various QA tests and procedures that need to be performed to identify the viability, performance and efficiency of these sensors for tracking system in CBM experiment.In particular QA in CBM-STS includes visual inspection, bulk and interstrip parameters measurements, sensor efficiency and total signal to noise ratio tests, measurements of irradiated sensors, bonding, low temperature performance and current stability tests. Results of various QA tests of sensor prototypes are shown.

  3. Test of scintillating bars coupled to Silicon Photomultipliers for a charged particle tracking device

    CERN Document Server

    Cecchini, S; Esposti, L Degli; Lax, I; Mandrioli, G; Mauri, N; Pasqualini, L; Patrizii, L; Pozzato, M; Sirri, G; Tenti, M

    2016-01-01

    The results obtained in laboratory tests, using scintillator bars read by silicon photomultipliers are reported. The present approach is the first step for designing a precision tracking system to be placed inside a free magnetized volume for the charge identification of low energy crossing particles. The devised system is demonstrated able to provide a spatial resolution better than 2 mm.

  4. Study of the Efficiency of Charge Matching Methods to Solve Ambiguous Tracks in 2-Sided Silicon Track Detectors

    CERN Document Server

    CERN. Geneva

    1994-01-01

    A GEANT-based simulation has been performed of the response of a layer of silicon micro-strips, located at 50 cm of radial distance from the LHC beam axis, in presence of a solenoidal magnetic field of 0.2 Tesla. Double-sided detectors have been considered, in which a charge signal is collected on the two sides of a silicon wafer, segmented in strips, the strips on one side being oriented at a small stereo angle relative to the strips of the other side. Then, a study was performed of the occurrence of ambiguous tracks in Pb-Pb events at the LHC energies, and of the efficiency of a method to resolve ambiguities based on the matching of the signals recorded on the two sides of the silicon detector. Results have shown that 84% of the tracks are not ambiguous, 7% are ambiguous (73% of them occurring in pairs, 16% in triples), 9% are joined together into a single cluster. Ambiguous pairs are resolved successfully by our algorithm with an average efficiency of 93%, and also the resolution for ambiguous triples apea...

  5. Mechanical engineering and design of silicon-based particle tracking devices

    International Nuclear Information System (INIS)

    The Mechanical Engineering and Electronics Division of the Los Alamos National Laboratory has been investigating silicon-based particle tracking device technology as part of the Superconducting Super Collider-sponsored silicon subsystem collaboration. Structural, thermal, and materials issues have been addressed. This paper discussed detector structural integrity and stability, including detailed finite element models of the silicon chip support and predictive methods used in designing with advanced composite materials. Electronic thermal loading and efficient dissipation of such energy using heat pipe technology has been investigated. The use of materials whose coefficients of thermal expansion are engineered to match silicon or to be near zero, as appropriate, have been explored. Material analysis and test results from radiation, chemical, and static loading are compared with analytical predictions and discussed. 1 ref., 2 figs., 1 tab

  6. A New Efficient-Silicon Area MDAC Synapse

    Directory of Open Access Journals (Sweden)

    Zied Gafsi

    2007-01-01

    Full Text Available Using the binary representation in the Multiplier digital to analog converter (MDAC synapse designs have crucial drawbacks. Silicon area of transistors, constituting the MDAC circuit, increases exponentially according to the number of bits. This latter is generated by geometric progression of common ratio equal to 2. To reduce this exponential increase to a linear growth, a new synapse named Arithmetic MDAC (AMDAC is designed. It functions with a new representation based on arithmetic progressions. Using the AMS CMOS 0.35µm technology the silicon area is reduced by a factor of 40%.

  7. Developmental experiments on large-area silicon solar cells

    Science.gov (United States)

    Silard, Andrei P.; Nani, Gabriel

    1989-05-01

    Practical ways of attenuating the severe limitations imposed by areal inhomogeneities on the performance of large-area solar cells fabricated on both p- and n-silicon wafers are described, and the results of tests are presented. The p(+)-n-n(+) and n(+)-p-p(+) cells were processed as bifacial devices and tested under both frontside and backside AM1 illumination. It is shown that the combination of a simple design and some of the technological approaches evaluated in this study result in low-cost high-efficiency large-area bifacial silicon solar cells that exhibit with good electrooptical performance.

  8. High-resolution tracking with silicon strip detectors for relativistic ions

    International Nuclear Information System (INIS)

    Tracking with silicon strip detectors for relativistic ions has been investigated using a 12C beam of 1.5 GeV/u at GSI. The ionization charge spectrum and the charge sharing between strips are presented. The strip cluster of carbon ion can be selected based on the cluster charge with high efficiency and little contamination. The spatial resolution of the silicon strip detectors is evaluated. The angular distribution of multiple Coulomb scattering was investigated with lead absorbers. The results are compared to the Moliere theory and the Gaussian approximation of GEANT calculations. (author)

  9. High-resolution tracking with silicon strip detectors for relativistic ions

    Energy Technology Data Exchange (ETDEWEB)

    Hou, S.R.; Alpat, B.; Ambrosi, G.; Balboni, C.; Battiston, R.; Burger, W.J.; Chang, Y.H.; Geissel, H.; Ionica, M.; Lustermann, W.; Maehlum, G.; Menichelli, M.; Pauluzzi, M.; Postolache, V.; Produit, N.; Rapin, D.; Ren, D.; Ribordy, M.; Sann, H.; Schardt, D.; Suemmerer, K.; Viertel, G

    1999-10-01

    Tracking with silicon strip detectors for relativistic ions has been investigated using a {sup 12}C beam of 1.5 GeV/u at GSI. The ionization charge spectrum and the charge sharing between strips are presented. The strip cluster of carbon ion can be selected based on the cluster charge with high efficiency and little contamination. The spatial resolution of the silicon strip detectors is evaluated. The angular distribution of multiple Coulomb scattering was investigated with lead absorbers. The results are compared to the Moliere theory and the Gaussian approximation of GEANT calculations. (author)

  10. High-resolution tracking with silicon strip detectors for relativistic ions

    CERN Document Server

    Hou, S R; Ambrosi, G; Balboni, C; Battiston, R; Burger, W J; Chang, Y H; Geissel, H; Ionica, M; Lustermann, W; Maehlum, G; Menichelli, M; Pauluzzi, M; Postolache, V; Produit, N; Rapin, D; Ren, D; Ribordy, M; Sann, H; Schardt, D; Sümmerer, K; Viertel, Gert M

    1999-01-01

    Tracking with silicon strip detectors for relativistic ions has been investigated using a sup 1 sup 2 C beam of 1.5 GeV/u at GSI. The ionization charge spectrum and the charge sharing between strips are presented. The strip cluster of carbon ion can be selected based on the cluster charge with high efficiency and little contamination. The spatial resolution of the silicon strip detectors is evaluated. The angular distribution of multiple Coulomb scattering was investigated with lead absorbers. The results are compared to the Moliere theory and the Gaussian approximation of GEANT calculations. (author)

  11. Beam test of a large area silicon drift detector

    International Nuclear Information System (INIS)

    The results from the tests of the first large area (4x4 cm2) planar silicon drift detector prototyp in a pion beam are reported. The measured position resolution in the drift direction is σ=40±10 μm. (orig.)

  12. 3D silicon sensors with variable electrode depth for radiation hard high resolution particle tracking

    International Nuclear Information System (INIS)

    3D sensors, with electrodes micro-processed inside the silicon bulk using Micro-Electro-Mechanical System (MEMS) technology, were industrialized in 2012 and were installed in the first detector upgrade at the LHC, the ATLAS IBL in 2014. They are the radiation hardest sensors ever made. A new idea is now being explored to enhance the three-dimensional nature of 3D sensors by processing collecting electrodes at different depths inside the silicon bulk. This technique uses the electric field strength to suppress the charge collection effectiveness of the regions outside the p-n electrodes' overlap. Evidence of this property is supported by test beam data of irradiated and non-irradiated devices bump-bonded with pixel readout electronics and simulations. Applications include High-Luminosity Tracking in the high multiplicity LHC forward regions. This paper will describe the technical advantages of this idea and the tracking application rationale

  13. Performance of the UA6 large-area silicon drift chamber prototype

    International Nuclear Information System (INIS)

    This report presents results on the performance of a large-area silicon drift detector (∝4x4 cm2), which has been designed for use as a high-resolution tracking device in the experiment UA6 at the CERN p-anti p collider. We give here the basic characteristics of the design, and report the first experimental results. The influence, on the detector's performance, of the adopted design criteria and of the quality of the semiconductors has been experimentally determined and is discussed. Results of the first drift-time calibration using an on-board device for charge injection are also given. (orig.)

  14. Small area silicon diffused junction x-ray detectors

    International Nuclear Information System (INIS)

    The low temperature performance of silicon diffused junction detectors in the measurement of low energy x-rays is reported. The detectors have an area of 0.04 cm2 and a thickness of 100 μm. The spectral resolutions of these detectors were found to be in close agreement with expected values indicating that the defects introduced by the high temperature processing required in the device fabrication were not deleteriously affecting the detection of low energy x-rays. Device performance over a temperature range of 77 to 1500K is given. These detectors were designed to detect low energy x-rays in the presence of minimum ionizing electrons. The successful application of silicon diffused junction technology to x-ray detector fabrication may facilitate the development of other novel silicon x-ray detector designs

  15. Momentum Resolution Improvement Technique for Silicon Tracking Detectors using dE/dx

    OpenAIRE

    Paganis, S. D.; Tang, Jaw-Luen

    2001-01-01

    A technique for improving the momentum resolution for low momentum charged particles in few layer silicon based trackers is presented. The particle momenta are determined from the measured Landau dE/dx distribution and the Bethe-Bloch formula in the 1/beta^2 region. It is shown that a factor of two improvement of the momentum determination is achieved as compared to standard track fitting methods. This improvement is important in large scale heavy ion experiments which cover the low transvers...

  16. Kalman filter tracking and vertexing in a silicon detector for neutrino physics

    International Nuclear Information System (INIS)

    This article describes the application of Kalman filter techniques for the tracking and vertexing of particles inside the NOMAD-STAR detector, a silicon vertex detector installed in NOMAD, one of the neutrino oscillation experiments at the CERN-SPS. The use of the Kalman filter simplifies computationally the tracking and vertex procedure for NOMAD-STAR. The alignment of NOMAD-STAR is shown as an example of the application of the Kalman filter for tracking purposes. The accuracy of the method is such that one obtains alignment residuals between 9 and 12 μm. Furthermore, a preliminary measure of the impact parameter (with an RMS ∼36 μm) illustrates the vertexing capabilities of this technique

  17. A New Efficient-Silicon Area MDAC Synapse

    OpenAIRE

    Zied Gafsi; Nejib Hassen; Mongia Mhiri; Kamel Besbes

    2007-01-01

    Using the binary representation in the Multiplier digital to analog converter (MDAC) synapse designs have crucial drawbacks. Silicon area of transistors, constituting the MDAC circuit, increases exponentially according to the number of bits. This latter is generated by geometric progression of common ratio equal to 2. To reduce this exponential increase to a linear growth, a new synapse named Arithmetic MDAC (AMDAC) is designed. It functions with a new representation based on arithmetic progr...

  18. Spatial Non-uniformity Measurements of Large Area Silicon Photodiodes

    OpenAIRE

    DURAK, Murat; SAMADOV, Farhad; TÜRKOĞLU, A. Kamuran

    2002-01-01

    Accurate determination of the responsivity of silicon photodiodes are highly desired in photometry. The change of responsivity over the surface, the so-called spatial non-uniformity, effects power measurements especially in photodiodes with large active areas. To study this effect, first an intensity-stabilized laser source-optics has been established. A purpose-built step-motor controlled two axis micro mechanical stage has been designed to scan the photodiode surface. In this stu...

  19. Investigations of surface characterization of silicone rubber due to tracking phenomena under a.c. and d.c. voltages

    Indian Academy of Sciences (India)

    Uma Maheswar Rao; S S M S Abdul Majeed; C Venkataseshaiah; R Sarathi

    2002-11-01

    In the present work, tracking phenomena has been studied with silicone rubber material under the a.c. and d.c. voltages following IEC-587 standards. The surface condition of the tracked zone was analysed using wide angle X-ray diffraction (WAXD) and thermogravimetric differential thermal analysis (TG–DTA) studies. The tracking time was different for a.c. and d.c. voltages.

  20. Enabling Technologies for Silicon Microstrip Tracking Detectors at the HL-LHC

    CERN Document Server

    Barth, C; Bloch, I.; Bögelspacher, F.; de Boer, W.; Daniels, M.; Dierlamm, A.; Eber, R.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Erfle, J.; Feld, L.; Garutti, E.; Gregor, I. -M.; Guthoff, M.; Hartmann, F.; Hauser, M.; Husemann, U.; Jakobs, K.; Junkes, A.; Karpinski, W.; Klein, K.; Kuehn, S.; Lacker, H.; Mahboubi, K.; Müller, Th.; Mussgiller, A.; Nürnberg, A.; Parzefall, U.; Poehlsen, T.; Poley, L.; Preuten, M.; Rehnisch, L.; Sammet, J.; Schleper, P.; Schuwalow, S.; Sperlich, D.; Stanitzki, M.; Steinbrück, G.; Wlochal, M.

    2016-01-01

    While the tracking detectors of the ATLAS and CMS experiments have shown excellent performance in Run 1 of LHC data taking, and are expected to continue to do so during LHC operation at design luminosity, both experiments will have to exchange their tracking systems when the LHC is upgraded to the high-luminosity LHC (HL-LHC) around the year 2024. The new tracking systems need to operate in an environment in which both the hit densities and the radiation damage will be about an order of magnitude higher than today. In addition, the new trackers need to contribute to the first level trigger in order to maintain a high data-taking efficiency for the interesting processes. Novel detector technologies have to be developed to meet these very challenging goals. The German groups active in the upgrades of the ATLAS and CMS tracking systems have formed a collaborative "Project on Enabling Technologies for Silicon Microstrip Tracking Detectors at the HL-LHC" (PETTL), which was supported by the Helmholtz Alliance "Phys...

  1. Real-Time MRI-Guided Catheter Tracking Using Hyperpolarized Silicon Particles

    Science.gov (United States)

    Whiting, Nicholas; Hu, Jingzhe; Shah, Jay V.; Cassidy, Maja C.; Cressman, Erik; Zacharias Millward, Niki; Menter, David G.; Marcus, Charles M.; Bhattacharya, Pratip K.

    2015-08-01

    Visualizing the movement of angiocatheters during endovascular interventions is typically accomplished using x-ray fluoroscopy. There are many potential advantages to developing magnetic resonance imaging-based approaches that will allow three-dimensional imaging of the tissue/vasculature interface while monitoring other physiologically-relevant criteria, without exposing the patient or clinician team to ionizing radiation. Here we introduce a proof-of-concept development of a magnetic resonance imaging-guided catheter tracking method that utilizes hyperpolarized silicon particles. The increased signal of the silicon particles is generated via low-temperature, solid-state dynamic nuclear polarization, and the particles retain their enhanced signal for ≥40 minutes—allowing imaging experiments over extended time durations. The particles are affixed to the tip of standard medical-grade catheters and are used to track passage under set distal and temporal points in phantoms and live mouse models. With continued development, this method has the potential to supplement x-ray fluoroscopy and other MRI-guided catheter tracking methods as a zero-background, positive contrast agent that does not require ionizing radiation.

  2. Large area high efficiency multicrystalline silicon solar cell

    Science.gov (United States)

    Shirasawa, Katsuhiko; Yamashita, Hironori; Fukui, Kenji; Takayama, Michihiro; Okada, Kenichi

    A high-efficiency, low-cost large-area multicrystalline silicon solar cell having a cell size of 15 cm x 15 cm and a substrate made by the casting method has been developed. The bifacial silicon nitride solar cell (BSNSC) fabrication process was used to construct the cell. By incorporating a new structure at the cell surface, an optimized back-surface field (BSF) process, and an electrode with a ratio of 5.2 percent into the BSNSC fabrication process, a conversion efficiency of 15.1 percent (global, AM1.5, 100 mW/sq cm, 25 C) has been obtained. The uniformity of the electrical performance of the cell has been studied by measuring the distribution of the spectral response at various points on the cell. The results of uniformity testing are presented.

  3. High-precision tracking and charge selection with silicon strip detectors for relativistic ions

    International Nuclear Information System (INIS)

    High-precision tracking and charge selection with silicon strip detectors for relativistic ions has been investigated using a 12C beam of 1.5 GeV/u at GSI with prototype modules developed for the AMS tracker. The ionization energy loss is measured and compared to the Landau-Vavilov theory for ions of charge number up to Z=6. The linearity in Z2 is examined. The capability to distinguish different Z values based on the ionization energy loss is evaluated. The spatial resolution of the silicon strip detectors is investigated for carbon ions. The angular distribution of multiple Coulomb scattering is studied with lead absorbers. The results are compared to the Moliere theory and the Gaussian approximation of GEANT calculations

  4. High-precision tracking and charge selection with silicon strip detectors for relativistic ions

    Energy Technology Data Exchange (ETDEWEB)

    Alpat, B.; Ambrosi, G.; Balboni, C.; Battiston, R.; Biland, A.; Bourquin, M.; Burger, W.J.; Chang, Y.H.; Chen, A.E.; Dinu, N.; Extermann, P.; Fiandrini, E.; Hou, S.R. E-mail: suen.hou@cern.ch; Ionica, M.; Ionica, R.; Lin, W.T.; Lustermann, W.; Maehlum, G.; Menichelli, M.; Pauluzzi, M.; Produit, N.; Rapin, D.; Ren, D.; Ribordy, M.; Sann, H.; Schardt, D.; Suemmerer, K.; Viertel, G.; Vite, D.; Wallraff, W.; Wu, S.X

    2000-05-21

    High-precision tracking and charge selection with silicon strip detectors for relativistic ions has been investigated using a {sup 12}C beam of 1.5 GeV/u at GSI with prototype modules developed for the AMS tracker. The ionization energy loss is measured and compared to the Landau-Vavilov theory for ions of charge number up to Z=6. The linearity in Z{sup 2} is examined. The capability to distinguish different Z values based on the ionization energy loss is evaluated. The spatial resolution of the silicon strip detectors is investigated for carbon ions. The angular distribution of multiple Coulomb scattering is studied with lead absorbers. The results are compared to the Moliere theory and the Gaussian approximation of GEANT calculations.

  5. Development of a silicon micro-strip detector for tracking high intensity secondary beams

    International Nuclear Information System (INIS)

    A single-sided silicon micro-strip detector (SSD) has been developed as a tracking detector for hadron experiments at J-PARC where secondary meson beams with intensities of up to 108 Hz are available. The performance of the detector has been investigated and verified in a series of test beam experiments in the years 2009–2011. The hole mobility was deduced from the analysis of cluster events. The beam rate dependence was measured in terms of timing resolution, signal-to-noise ratio, and hit efficiency. This paper describes the detector with its read-out system, details of the test experiments, and discusses the performance achieved

  6. Development of a silicon micro-strip detector for tracking high intensity secondary beams

    Energy Technology Data Exchange (ETDEWEB)

    Kiuchi, R. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Asano, H. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Hasegawa, S. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Honda, R. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Ichikawa, Y. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Imai, K. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Joo, C.W. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Nakazawa, K. [Physics Department, Gifu University, Gifu 501-1193 (Japan); Sako, H.; Sato, S. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Shirotori, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Sugimura, H. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Tanida, K., E-mail: tanida@phya.snu.ac.kr [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Watabe, T. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2014-11-01

    A single-sided silicon micro-strip detector (SSD) has been developed as a tracking detector for hadron experiments at J-PARC where secondary meson beams with intensities of up to 10{sup 8} Hz are available. The performance of the detector has been investigated and verified in a series of test beam experiments in the years 2009–2011. The hole mobility was deduced from the analysis of cluster events. The beam rate dependence was measured in terms of timing resolution, signal-to-noise ratio, and hit efficiency. This paper describes the detector with its read-out system, details of the test experiments, and discusses the performance achieved.

  7. Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array

    OpenAIRE

    Esteve Bosch, Raul; MARÍ ROMERO, ANTONIO FRANCISCO; Mora Mas, Francisco José; Pérez Aparicio, José Luis; Toledo Alarcón, José Francisco; Alvarez, V.; Borges, F. I. G.; Carcel, S.; Castel, J.; Cebrian, S.; Cervera, A.; Conde, C. A. N.; Dafni, T.; T. H. V. T. Dias; Diaz, J.

    2013-01-01

    NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature o...

  8. Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array

    CERN Document Server

    Álvarez, V; Cárcel, S; Castel, J; Cebrián, S; Cervera, A; Conde, C A N; Dafni, T; Dias, T H V T; Díaz, J; Egorov, M; Esteve, R; Evtoukhovitch, P; Fernandes, L M P; Ferrario, P; Ferreira, A L; Freitas, E D C; Gehman, V M; Gil, A; Goldschmidt, A; Gómez, H; Gómez-Cadenas, J J; González-Díaz, D; Gutiérrez, R M; Hauptman, J; Morata, J A Hernando; Herrera, D C; Iguaz, F J; Irastorza, I G; Jinete, M A; Labarga, L; Laing, A; Liubarsky, I; Lopes, J A M; Lorca, D; Losada, M; Luzón, G; Marí, A; Martín-Albo, J; Martínez, A; Martínez, G; Miller, T; Moiseenko, A; Monrabal, F; Monteiro, C M B; Mora, F J; Moutinho, L M; Vidal, J Muñoz; da Luz, H Natal; Navarro, G; Nebot-Guinot, M; Nygren, D; Oliveira, C A B; Palma, R; Pérez, J; Aparicio, J L Pérez; Renner, J; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Seguí, L; Serra, L; Shuman, D; Simón, A; Sofka, C; Sorel, M; Toledo, J F; Tomás, A; Torrent, J; Tsamalaidze, Z; Veloso, J F C A; Villar, J A; Webb, R; White, J T; Yahlali, N

    2013-01-01

    NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature of electrons in dense gas. Demonstrating the ability to identify the MIP and ``blob'' regions. Moreover, the SiPM tracking plane allows for the definition of a large fiducial region in which an excellent energy resolution of 1.82% FWHM at 511 keV has been measured (a value which extrapolates to 0.83% at the xenon Qbetabeta).

  9. Innovative carbon nanotube-silicon large area photodetector

    International Nuclear Information System (INIS)

    We report on a new photodetector fabricated using carbon nanostructures grown on a silicon substrate. This device exhibits low noise, a good conversion efficiency of photons into electrical current and a good signal linearity in a wide range of radiation wavelengths ranging from ultraviolet to infrared at room temperature. The maximum quantum efficiency of 37% at 880 nm has been measured without signal amplification. Such innovative devices can be easily produced on large scales by Chemical Vapour Deposition (CVD) through a relatively inexpensive chemical process, which allows large sensitive areas from a few mm2 up to hundreds of cm2 to be covered.

  10. Low cost, large area silicon detectors for calorimetry

    International Nuclear Information System (INIS)

    Trapezoidal detectors with 28 cm2 active area have been fabricated on >2500 Ωcm, 4 in. diameter n-type silicon wafers. Instead of the commonly used ion implantation method, low-cost, high volume solid state diffusion technology along with phosphosilicate-glass and TCA gettering was adopted for boron and phosphorus doping. Typically the diode dark current was 15 μA at sign 100 volts. Efforts are being made to obtain a finished device yield of 80% to meet the $2/cm2 price goal of SSC semiconductor detector group. 20 refs., 4 figs

  11. Study of the Tracking Method and Expected Performance of the Silicon Pixel Inner Tracker Applied in BESIII

    CERN Document Server

    Xiu, Qinglei; Li, Weidong; Liu, Huaimin; Ma, Qiumei; Ouyang, Qun; Qin, Zhonghua; Wang, Liangliang; Wu, Linghui; Yuan, Ye; Zhang, Yao

    2015-01-01

    The inner drift chamber of the BESIII is encountering serious aging problem after five year's running. For the first layer, the decrease in gas gain is about 26% from 2009 to 2013. The upgrade of the inner tracking detector has become an urgent problem for the BESIII experiment. An inner tracker using CMOS pixel sensors is an important candidate because of its great advantages on spatial resolution and radiation hardness. In order to carry out a Monte Carlo study on the expected performance, a Geant4-based full simulation for the silicon pixel detector has been implemented. The tracking method combining the silicon pixel inner tracker and outer drift chamber has been studied and a preliminary reconstruction software was developed. The Monte Carlo study shows that the performances including momentum resolution, vertex resolution and the tracking efficiency are significantly improved due to the good spatial resolution and moderate material budget of the silicon pixel detector.

  12. Development of radiation-hard sensors for the CBM silicon tracking system using simulation approach

    International Nuclear Information System (INIS)

    TCAD simulations have been done to understand the radiation damage in Double Sided silicon Strip Detectors for the Silicon Tracking System of the upcoming CBM experiment. We are using Sentaurus Device, a subpackage of SYNOPSYS. We have found a good agreement between simulations and measurements in terms of leakage current, full depletion voltage (VFD) and capacitances. To simulate radiation damage, we have changed the effective doping concentration and minority carrier lifetime with fluence (φ). We applied the University of Perugia trap model for the defect levels introduced with φ for both n-type and p-type silicon. The extracted damage constant matches with the experimental values. It has been found that the breakdown occurs in the coupling oxide at around 165 V and is independent of fluence while the VFD increases with φ due to reverse annealing. Hence we have to operate our detectors under-depleted. It is important to understand whether these DSSDs will be operational upto a φ of 1 x 1015 neqcm-2. From interstrip parameters namely interstrip capacitance (Cint) and interstrip resistance (Rint) one can understand strip isolation. Cint and Rint have been studied in detail with φ and it has been found that these DSSDs will be efficient even after maximum fluence.

  13. Silicon strip tracking detector development and prototyping for the Phase-II upgrade of the ATLAS experiment

    Science.gov (United States)

    Kuehn, S.

    2016-07-01

    In about ten years from now, the Phase-II upgrade of the LHC will be carried out. Due to increased luminosity, a severe radiation dose and high particle rates will occur for the experiments. In consequence, several detector components will have to be upgraded. In the ATLAS experiment, the current inner detector will be replaced by an all-silicon tracking detector with the goal of at least delivering the present detector performance also in the harsh Phase-II LHC conditions. This report presents the current planning and results from first prototype measurements of the upgrade silicon strip tracking detector.

  14. Formation of ion tracks in amorphous silicon nitride films with MeV C60 ions

    International Nuclear Information System (INIS)

    Amorphous silicon nitride (a-SiN) films (thickness 5–100 nm) were irradiated with 0.12–5 MeV C60, 100 MeV Xe, 200 MeV Kr, and 200 and 420 MeV Au ions. Ion tracks were clearly observed using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) except for 100 MeV Xe and 200 MeV Kr. The observed HAADF-STEM images showed that the ion tracks consist of a low density core (0.5–2 nm in radius) and a high density shell (several nm in radius). The observed core and shell radii are not simply correlated with the electronic energy loss indicating that the nuclear energy loss plays an important role in the both core and shell formations. The observed track radii were well reproduced by the unified thermal spike model with two thresholds for shell and core formations

  15. The Silicon Tracking System of the CBM experiment at FAIR : development of microstrip sensors and signal transmission lines for a low-mass, low-noise system

    OpenAIRE

    Singla, Minni (Dr.)

    2014-01-01

    In this thesis, different physical and electrical aspects of silicon microstrip sensors and low-mass multi-line readout cables have been investigated. These silicon microstrip sensors and readout cables will be used in the Silicon Tracking System (STS) of the fixed-target heavy-ion Compressed Baryonic Matter (CBM) experiment which is under development at the upcoming Facility for Antiproton and ion Research (FAIR) in Darmstadt, Germany. The highly segmented low-mass tracking system is a centr...

  16. Track reconstruction in heavy ion collisions with the CMS silicon tracker

    CERN Document Server

    Roland, C

    2006-01-01

    The Large Hadron Collider at CERN will collide protons at \\sqrtS = 14TeV and lead ions at \\sqrt$\\S_{NN}$. The study of heavy ion collisions is an integral part of the physics program of the Compact Muon Solenoid (CMS). Central heavy ion events at LHC energies are expected to produce a multiplicity of up to 3500 charged particles per unit of rapidity. The CMS detector features a large acceptance and high resolution silicon tracker consisting of pixel and strip detector layers. We describe the algorithms used for pattern recognition in the very high track density environment of heavy ion collisions. Detailed studies using the full detector simulation and reconstruction are presented and achieved reconstruction efficiencies, fake rates and resolutions are discussed.

  17. The STAR silicon vertex tracker: a large area silicon drift detector

    CERN Document Server

    Lynn, D; Beuttenmüller, Rolf H; Caines, H; Chen, W; Dimassimo, D; Dyke, H; Elliot, D; Eremin, V; Grau, M; Hoffmann, G W; Humanic, T; Ilyashenko, Yu S; Kotov, I; Kraner, H W; Kuczewski, P; Leonhardt, B; Li, Z; Liaw, C J; Lo Curto, G; Middelkamp, P; Minor, R; Munhoz, M; Ott, G; Pandey, S U; Pruneau, C A; Rykov, V L; Schambach, J; Sedlmeir, J; Soja, B; Sugarbaker, E R; Takahashi, J; Wilson, K; Wilson, R

    2000-01-01

    The Solenoidal Tracker At RHIC-Silicon Vertex Tracker (STAR-SVT) is a three barrel microvertex detector based upon silicon drift detector technology. As designed for the STAR-SVT, silicon drift detectors (SDDs) are capable of providing unambiguous two-dimensional hit position measurements with resolutions on the order of 20 mu m in each coordinate. Achievement of such resolutions, particularly in the drift direction coordinate, depends upon certain characteristics of silicon and drift detector geometry that are uniquely critical for silicon drift detectors hit measurements. Here we describe features of the design of the STAR-SVT SDDs and the front-end electronics that are motivated by such characteristics.

  18. Radar track segmentation with cubic splines for collision risk models in high density terminal areas

    OpenAIRE

    Cózar, J.; Saez Nieto, Francisco Javier; Ricaud Álvarez, Enrique

    2014-01-01

    This paper presents a method to segment airplane radar tracks in high density terminal areas where the air traffic follows trajectories with several changes in heading, speed and altitude. The radar tracks are modelled with different types of segments, straight lines, cubic spline function and shape preserving cubic function. The longitudinal, lateral and vertical deviations are calculated for terminal manoeuvring area scenarios. The most promising model of the radar tracks resulted from a mi...

  19. tkLayout: a design tool for innovative silicon tracking detectors

    International Nuclear Information System (INIS)

    engineers and simulation experts to focus their efforts on other important or specific issues. Even if tkLayout was designed for the CMS tracker upgrade project, its flexibility makes it experiment-agnostic, so that it could be easily adapted to model other tracking detectors. The technology behind tkLayout is presented, as well as some of the results obtained in the context of the CMS silicon tracker design studies

  20. tkLayout: a design tool for innovative silicon tracking detectors

    Science.gov (United States)

    Bianchi, G.

    2014-03-01

    and simulation experts to focus their efforts on other important or specific issues. Even if tkLayout was designed for the CMS tracker upgrade project, its flexibility makes it experiment-agnostic, so that it could be easily adapted to model other tracking detectors. The technology behind tkLayout is presented, as well as some of the results obtained in the context of the CMS silicon tracker design studies.

  1. A Level-1 Tracking Trigger for the CMS upgrade using stacked silicon strip detectors and advanced pattern technologies

    Science.gov (United States)

    Boudoul, G.

    2013-01-01

    Experience at high luminosity hadrons collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events. The design of a tracking based trigger for the High Luminosity LHC (HL-LHC) is an extremely challenging task, and requires the identification of high-momentum particle tracks as a part of the Level 1 Trigger. Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors, and reconstructing tracks at L1 by employing an Associative Memory approach. The progresses on the design and development of this micro-strip stacked prototype modules and the performance of few prototype detectors will be presented. Preliminary results of a simulated tracker layout equipped with stacked modules are discussed in terms of pT resolution and triggering capabilities. Finally, a discussion on the L1 architecture will be given.

  2. First measurements of segmented silicon tracking detectors with built-in multiplication layer

    Energy Technology Data Exchange (ETDEWEB)

    Cavallaro, Emanuele; Lange, Jörn; Lopez Paz, Ivan; Grinstein, Sebastian [Institut de Física d' Altes Energies, IFAE, Barcelona (Spain); Baselga, Marta; Greco, Virginia; Quirion, David; Pellegrini, Giulio [Centro Nacional de Microelectrónica, CNM-IMB (CSIC), Barcelona (Spain)

    2015-10-01

    Silicon sensors with a built-in multiplication layer, also known as Low Gain Avalanche Detectors (LGAD), are a new technology of potentially radiation hard silicon sensors developed at CNM (Centro Nacional de Microelectrónica) in the framework of the CERN-RD50 collaboration. The concept of the LGAD technology is to produce a tracking sensor with an intrinsic low gain due to charge multiplication in order to enhance the signal-to-noise ratio. This makes LGAD detectors appealing for the high energy physics community which foresees a possible application in harsh radiation environments such as the inner detectors of the experiments at the High Luminosity LHC, where a fluence of 2×10{sup 16} n{sub eq}/cm{sup 2} is expected in the innermost pixel layer of the tracker. LGAD pad diodes with a multiplication factor of 10 at 200 V before irradiation have been produced and studied but it still has to be proven that this technology can be applied to segmented devices. The electric field profile at the p–n junction plays a crucial role for the multiplication mechanism that could be affected by implantation edge effects in highly segmented devices. In this paper the results of the first measurements of segmented LGAD devices from 285 μm thick float zone wafers will be discussed. Time resolved Transient-Current-Technique analysis has been performed on strip devices and charge collection measurements have been carried out on pixel detectors to test the LGAD technology on highly segmented devices.

  3. Robust track based alignment of the ATLAS silicon detectors and assessing patron distribution uncertainties in drell-yan processes

    OpenAIRE

    Heinemann, Florian.; Weidberg, Tony; Dr. Tony Weidberg

    2007-01-01

    The ATLAS Experiment is one of the four large detectors located at the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. In summer 2008, ATLAS is expected to start collecting data from proton-proton collisions at 14 TeV centre-of-mass energy. In the centre of the detector, the reconstruction of charged particle tracks is performed by silicon and drift tube based sub-detectors. In order to achieve the ATLAS physics goals the resolutions of the measured track parameters...

  4. Evaluation of molten area in micro-welding of monocrystalline silicon and glass

    Science.gov (United States)

    Nordin, I. H. W.; Okamoto, Y.; Miyamoto, I.; Okada, A.

    2016-02-01

    Characteristics of the molten area in micro-welding of monocrystalline silicon and glass are described. In this study, 4 types of laser beam, which are nanosecond pulsed laser and picosecond pulsed laser of 532 nm and 1064 nm in wavelength were used for joining monocrystalline silicon and glass. Influence of wavelength and pulse duration on microwelding of monocrystalline silicon and glass was experimentally investigated under the same spot diameter, and the molten area of monocrystalline silicon and glass was characterized. A splash area of molten silicon with 532 nm wavelength was wider than that with 1064 nm in a nanosecond pulse laser. However, its splash area of molten silicon with 1064 nm changed drastically at certain pulse energy of 11 μJ in a nanosecond pulse laser. On the other hand, 12.5 ps pulsed laser still kept a stable molten area appearance even at pulse energy of 11 μJ. A splash area of molten silicon around the weld bead line was obvious in the nanosecond pulsed laser. On the other hand, there was no remarkable molten splash around the weld bead line in the picosecond pulsed laser. It is concluded that the combination of picosecond pulse duration and infrared wavelength leads to a stable molten area appearance of the weld bead.

  5. Finite element simulations of low-mass readout cables for the CBM Silicon Tracking System using RAPHAEL

    Science.gov (United States)

    Singla, M.; Chatterji, S.; Müller, W. F. J.; Kleipa, V.; Heuser, J. M.

    2014-01-01

    The first three-dimensional simulation study of thin multi-line readout cables using finite element simulation tool RAPHAEL is being reported. The application is the Silicon Tracking System (STS) of the fixed-target heavy-ion experiment Compressed Baryonic Matter (CBM), under design at the forthcoming accelerator center FAIR in Germany. RAPHAEL has been used to design low-mass analog readout cables with minimum possible Equivalent Noise Charge (ENC). Various trace geometries and trace materials have been explored in detail for this optimization study. These cables will bridge the distance between the microstrip detectors and the signal processing electronics placed at the periphery of the silicon tracking stations. SPICE modeling has been implemented in Sentaurus Device to study the transmission loss (dB loss) in cables and simulation has been validated with measurements. An optimized design having minimum possible ENC, material budget and transmission loss for the readout cables has been proposed.

  6. Measurement of rare probes with the silicon tracking system of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    The Compressed Baryonic Matter (CBM) experiment at FAIR will explore the phase diagram of strongly interacting matter at highest net baryon densities and moderate temperatures. The CBM physics program will be started with beams delivered by the SIS 100 synchrotron, providing energies from 2 to 14 GeV/nucleon for heavy nuclei, up to 14 GeV/nucleon for light nuclei, and 29 GeV for protons. The highest net baryon densities will be explored with ion beams up to 45 GeV/nucleon energy delivered by SIS 300 in the next stage of FAIR. Collision rates up to 107 per second are required to produce very rare probes with unprecedented statistics in this energy range. Their signatures are complex. These conditions call for detector systems designed to meet the extreme requirements in terms of rate capability, momentum and spatial resolution, and a novel DAQ and trigger concept which is not limited by latency but by throughput. In this paper we outline the concepts of CBM's central detector, the Silicon Tracking System, and of the First-Level Event Selector, a dedicated computing farm to reduce on-line the raw data volume by up to three orders of magnitude to a recordable rate. Progress with the development of detector and software algorithms are discussed and examples of performance studies on the reconstruction of rare probes at SIS 100 and SIS 300 energies given

  7. Recent Developments on the Silicon Drift Detector readout scheme for the ALICE Inner Tracking System

    CERN Document Server

    Mazza, G; Bonazzola, G C; Bonvicini, V; Cavagnino, D; Cerello, P G; De Remigis, P; Falchieri, D; Gabrielli, A; Gandolfi, E; Giubellino, P; Hernández, R; Masetti, M; Montaño-Zetina, L M; Nouais, D; Rashevsky, A; Rivetti, A; Tosello, F

    1999-01-01

    Proposal of abstract for LEB99, Snowmass, Colorado, 20-24 September 1999Recent developments of the Silicon Drift Detector (SDD) readout system for the ALICE Experiment are presented. The foreseen readout system is based on 2 main units. The first unit consists of a low noise preamplifier, an analog memory which continuously samples the amplifier output, an A/D converter and a digital memory. When the trigger signal validates the analog data, the ADCs convert the samples into a digital form and store them into the digital memory. The second unit performs the zero suppression/data compression operations. In this paper the status of the design is presented, together with the test results of the A/D converter, the multi-event buffer and the compression unit prototype.Summary:In the Inner Tracker System (ITS) of the ALICE experiment the third and the fourth layer of the detectors are SDDs. These detectors provide the measurement of both the energy deposition and the bi-dimensional position of the track. In terms o...

  8. Selective-area laser deposition (SALD) Joining of silicon carbide with silicon carbide filler

    Science.gov (United States)

    Harrison, Shay Llewellyn

    Selective Area Laser Deposition (SALD) is a gas-phase, solid freeform fabrication (SFF) process that utilizes a laser-driven, pyrolytic gas reaction to form a desired solid product. This solid product only forms in the heated zone of the laser beam and thus can be selectively deposited by control of the laser position. SALD Joining employs the SALD method to accomplish 'welding' of ceramic structures together. The solid reaction product serves as a filler material to bond the two parts. The challenges involved with ceramic joining center around the lack of a liquid phase, little plastic deformation and diffusivity and poor surface wetting for many ceramic materials. Due to these properties, traditional metal welding procedures cannot be applied to ceramics. Most alternative ceramic welding techniques use some form of a metal addition to overcome these material limitations. However, the metal possesses a lower ultimate use temperature than the ceramic substrate and therefore it decreases the temperature range over which the joined part can be safely used. SALD Joining enjoys several advantages over these ceramic welding procedures. The solid filler material chemistry can be tailored to match the type of ceramic substrate and therefore fabricate monolithic joints. The SALD filler material bonds directly to the substrate and the joined structure is made in a one step process, without any post-processing. The research documented in this dissertation focused on SALD Joining of silicon carbide structures with silicon carbide filler material. A historical progression of gas-phase SFF research and a literature review of the most prominent ceramic joining techniques are provided. A variety of SiC substrates were examined, as were various conditions of gas precursor pressures and mixtures, laser beam scan speed and joint configuration. The SALD material was characterized for composition and structure by x-ray diffraction, transmission electron microscopy and nuclear magnetic

  9. Calibration, alignment and long-term performance of the CMS silicon tracking detector

    Energy Technology Data Exchange (ETDEWEB)

    Butz, E.

    2009-03-15

    With an active area of more than 200 m{sup 2}, the CMS silicon strip detector is the largest silicon tracker ever built. It consists of more than 15,000 individual silicon modules which have to meet very high standards in terms of noise behavior and electronic crosstalk, as well as their exact positioning within the tracker. Furthermore, the modules will be exposed to a harsh radiation environment over the lifetime of the tracker. This thesis deals with several of the above-mentioned aspects. In the first part, individual modules are investigated using a testbeam. Some of the modules were irradiated up to an integrated dose which corresponds to the expected one over the life time of the tracker. These modules are investigated with respect to their signal-to-noise behavior, and their cross-talk. Several operational parameters are varied, such as the temperature and the bias voltage. It is shown that the modules behave as expected. The signal-to-noise ratio is well above the specifications and the cross-talk increases only very moderately with irradiation. Furthermore, the spatial resolution of the modules is investigated. Different cluster algorithms are utilized and compared. It is shown that the spatial resolution is not much affected by irradiation and that the spatial resolution can be improved with respect to the current standard reconstruction. In the second part, larger structures of the silicon tracker are studied during the socalled 'tracker slice-test'. Two sectors from one of the tracker end caps are investigated. Special emphasis is given to the commissioning of the system and the monitoring of the various commissioning parameters. Furthermore, the noise of the system is investigated as a function of the ambient temperature and different powering schemes. It is shown that the noise of the system behaves as expected. The noise is stable within 2% for different powering schemes. Also possible failures of components are investigated and persistent

  10. Calibration, alignment and long-term performance of the CMS silicon tracking detector

    International Nuclear Information System (INIS)

    With an active area of more than 200 m2, the CMS silicon strip detector is the largest silicon tracker ever built. It consists of more than 15,000 individual silicon modules which have to meet very high standards in terms of noise behavior and electronic crosstalk, as well as their exact positioning within the tracker. Furthermore, the modules will be exposed to a harsh radiation environment over the lifetime of the tracker. This thesis deals with several of the above-mentioned aspects. In the first part, individual modules are investigated using a testbeam. Some of the modules were irradiated up to an integrated dose which corresponds to the expected one over the life time of the tracker. These modules are investigated with respect to their signal-to-noise behavior, and their cross-talk. Several operational parameters are varied, such as the temperature and the bias voltage. It is shown that the modules behave as expected. The signal-to-noise ratio is well above the specifications and the cross-talk increases only very moderately with irradiation. Furthermore, the spatial resolution of the modules is investigated. Different cluster algorithms are utilized and compared. It is shown that the spatial resolution is not much affected by irradiation and that the spatial resolution can be improved with respect to the current standard reconstruction. In the second part, larger structures of the silicon tracker are studied during the socalled ''tracker slice-test''. Two sectors from one of the tracker end caps are investigated. Special emphasis is given to the commissioning of the system and the monitoring of the various commissioning parameters. Furthermore, the noise of the system is investigated as a function of the ambient temperature and different powering schemes. It is shown that the noise of the system behaves as expected. The noise is stable within 2% for different powering schemes. Also possible failures of components are investigated and persistent defects are

  11. A large area Micromegas TPC for tracking at the ILC

    International Nuclear Information System (INIS)

    The study of the fundamental building blocks of matter necessitates always more powerful accelerators. New particles are produced in high energy collisions of protons or electrons. The by-Products of these collisions are detected in large apparatus surrounding the interaction point. The 125 GeV Higgs particle discovered at LHC will be studied in detail in the next e+e- collider. The leading project for this is called ILC. The team that I joined is working on the R and D for a Time Projection Chamber (TPC) to detect the charged tracks by the ionization they leave in a gas volume, optimised for use at ILC. This primary ionization is amplified by the so-Called Micromegas device, with a charge-Sharing anode made of a resistive-Capacitive coating. After a presentation of the physics motivation for the ILC and ILD detector, I will review the principle of operation of a TPC (Chapter 2) and underline the advantages of the Micromegas readout with charge sharing. The main part of this PhD work concerns the detailed study of up to 12 prototypes of various kinds. The modules and their readout electronics are described in Chapter 3. A test-Bench setup has been assembled at CERN (Chapter 4) to study the response to a 55Fe source, allowing an energy calibration and a uniformity study. In Chapter 5, the ion back-flow is studied using a bulk Micromegas and the gas gain is measured using a calibrated electronics chain. With the same setup, the electron transparency is measured as a function of the field ratio (drift/amplification). Also, several beam tests have been carried out at DESY with a 5 GeV electron beam in a 1 T superconducting magnet. These beam tests allowed the detailed study of the spatial resolution. In the final test, the endplate was equipped with seven modules, bringing sensitivity to misalignment and distortions. Such a study required software developments (Chapter 6) to make optimal use of the charge sharing and to reconstruct multiple tracks through several

  12. Gamma large area silicon telescope: Applying SI strip detector technology to the detection of gamma rays in space

    Science.gov (United States)

    Atwood, W. B.; Bloom, E. D.; Godfrey, G. L.; Hertz, P. L.; Lin, Ying-Chi; Nolan, P. L.; Snyder, A. E.; Taylor, R. E.; Wood, K. S.; Michelson, P. F.

    1992-12-01

    The recent discoveries and excitement generated by EGRET (Energetic Gamma Ray Experiment Telescope) (presently operating on CGRO (Compton Gamma Ray Observatory)) has prompted an investigation into modern technologies ultimately leading to the next generation space based gamma ray telescope. The goal is to design a detector that would increase the data acquisition rate by almost two orders of magnitude beyond EGRET, while at the same time improving on the angular resolution, the energy measurement of reconstructed gamma rays and the triggering capability of the instrument. The proposed GLAST (Gamma Ray Large Area Silicon Telescope) instrument is based on silicon particle detectors that offer the advantages of no consumables, no gas volume, robust (versus fragile), long lived, and self triggering. The GLAST detector is roughly modeled after EGRET in that a tracking module precedes a calorimeter. The GLAST tracker has planes of cross strip (x, y) 300 micrometer match silicon detectors coupled to a thin radiator to measure the coordinates of converted electron-positron pairs. An angular resolution of 0.1 deg at high energy is possible (the low energy angular resolution 100 MeV would be about 2 deg, limited by multiple scattering). The increased depth of the GLAST calorimeter over EGRET's extends the energy range to about 300 GeV.

  13. CATS a cellular automaton for tracking in silicon for the HERA-B vertex detector

    CERN Document Server

    Abt, I; Kisel, I; Masciocchi, S

    2002-01-01

    The new track reconstruction program CATS developed for the Vertex Detector System of the HERA-B experiment at DESY is presented. It employs a cellular automaton for track searching and the Kalman filter for track fitting. This results in a very fast algorithm that combines highly efficient track recognition with accurate and reliable track parameter estimation. To reduce the computational cost of the fit an optimized numerical implementation of the Kalman filter is used. Alternative approaches to the track reconstruction in the VDS are also discussed. Since 1999, after extensive tests on simulated data, CATS has been employed to reconstruct experimental data collected in HERA-B. Results regarding tracking performance, the accuracy of track parameter estimates and CPU time consumption are presented.

  14. CATS: a cellular automaton for tracking in silicon for the HERA-B vertex detector

    International Nuclear Information System (INIS)

    The new track reconstruction program CATS developed for the Vertex Detector System of the HERA-B experiment at DESY is presented. It employs a cellular automaton for track searching and the Kalman filter for track fitting. This results in a very fast algorithm that combines highly efficient track recognition with accurate and reliable track parameter estimation. To reduce the computational cost of the fit an optimized numerical implementation of the Kalman filter is used. Alternative approaches to the track reconstruction in the VDS are also discussed. Since 1999, after extensive tests on simulated data, CATS has been employed to reconstruct experimental data collected in HERA-B. Results regarding tracking performance, the accuracy of track parameter estimates and CPU time consumption are presented

  15. A Silicon UCN Detector With Large Area and With Analysis of UCN Polarization

    OpenAIRE

    Lasakov, M.; Serebrov, A.; Khusainov, A.; Pustovoit, A.; Borisov, Yu.; Fomin, A.; Geltenbort, P; Kon’kov, O.; Kotina, I.; Shablii, A.; Solovei, V.; Vasiliev, A.

    2005-01-01

    A silicon ultracold neutron (UCN) detector with an area of 45 cm2 and with a 6LiF converter is developed at St. Petersburg Nuclear Physics Institute (PNPI). The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at Institut Max von Laue – Paul Langevin (ILL). The sandwich-type detector from two silicon plates with a 6LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarizatio...

  16. A large area silicon UCN detector with the analysis of UCN polarization

    Science.gov (United States)

    Lasakov, M. S.; Serebrov, A. P.; Khusainov, A. Kh.; Pustovoit, A.; Borisov, Yu. V.; Fomin, A. K.; Geltenbort, P.; Kon'kov, O. I.; Kotina, I. M.; Shablii, A. I.; Solovei, V. A.; Vasiliev, A. V.

    2005-06-01

    A silicon UCN detector with an area of 45 cm2 and with a 6LiF converter was developed at PNPI. The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at ILL. The sandwich-type detector from two silicon plates with a 6LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarization was developed and tested. The analyzing power of this detector assembly reaches up to 75% for the main part of UCN spectrum. This UCN detector with analysis of UCN polarization can be used in the new EDM spectrometer.

  17. Sol-gel preparation of low oxygen content, high surface area silicon nitride and imidonitride materials.

    Science.gov (United States)

    Sardar, Kripasindhu; Bounds, Richard; Carravetta, Marina; Cutts, Geoffrey; Hargreaves, Justin S J; Hector, Andrew L; Hriljac, Joseph A; Levason, William; Wilson, Felix

    2016-04-01

    Reactions of Si(NHMe)4 with ammonia are effectively catalysed by small ammonium triflate concentrations, and can be used to produce free-standing silicon imide gels. Firing at various temperatures produces amorphous or partially crystallised silicon imidonitride/nitride samples with high surface areas and low oxygen contents. The crystalline phase is entirely α-Si3N4 and structural similarities are observed between the amorphous and crystallised materials. PMID:26931152

  18. Development of large area silicon detectors for calorimetrics applications

    International Nuclear Information System (INIS)

    P-I-N diodes, operating partially or fully depleted, have been made with a planar process with a high resistivity 3k-6k ohm cm (111) FZ silicon. The reliability and repeatability of the process is guaranteed by the techniques already known and used in production of discrete power devices, with appropriate adaptation. The processes developed is IC compatible. The leakage control is obtained by reducing residual ion implantation damage with high temperature annealing and by proved gettering techniques. A value of 5 nA/cm2 has been obtained. (orig.)

  19. The use of large area silicon sensors for thermal neutron detection

    International Nuclear Information System (INIS)

    The use of large area planar silicon detectors coupled with gadolinium foils has been investigated to develop a thermal neutron detector having a large area-efficiency (Aε) product. Noise levels due to high detector capacitance limit the size of silicon detectors that can be utilized. Calculations using the Monte Carlo code, MCNP, have been made to determine the variation of intrinsic detection efficiency as a function of the discriminator threshold level required to eliminate the detector noise. Measurements of the noise levels for planar silicon detectors of various resistivities (400, 3000 and 5000 Ω cm) have been made and the optimal detector area-efficiency products have been determined. The response of a Si-Gd-Si sandwich detector with areas between 1 cm2 and 10.5 cm2 is presented and the effects of the detector capacitance and reverse current are discussed. ((orig.))

  20. Development of large area and thin silicon dE/dX detectors

    International Nuclear Information System (INIS)

    The aim of this report is to demonstrate the feasibility of thin dE/dX detectors of large areas with today available ultrathin silicon membranes. With a fast and easy manufacturing procedure, very performant surface barriers with areas up to 1010 mm2 and about 50 μm thick have been realized

  1. High surface area silicon carbide-coated carbon aerogel

    Science.gov (United States)

    Worsley, Marcus A; Kuntz, Joshua D; Baumann, Theodore F; Satcher, Jr, Joe H

    2014-01-14

    A metal oxide-carbon composite includes a carbon aerogel with an oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, raising the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite. The step of providing a carbon aerogel can provide an activated carbon aerogel or provide a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust. Carbon aerogels can be coated with sol-gel silica and the silica can be converted to silicone carbide, improved the thermal stability of the carbon aerogel.

  2. The Aalborg case - GPS tracking of 169 young adults in a Danish central city area

    DEFF Research Database (Denmark)

    Harder, Henrik; Bro, Peter; Knudsen, Anne-Marie

    Recent developments in the global positioning system (GPS) and the global system for mobile communications, or third generation technology (GSM/3G), have enabled an increasingly simple and cost-effective tracking of human activity in urban areas through the use of mobile telephony for the...... was based on a unique sample of movement data gleaned from 169 young adults aged 16 to 20 years. Each person was GPS-tracked over a period of seven days in 2008-2009 to record their movements in and uses of spaces in the central city area of Aalborg, which is Denmark’s fourth-largest city, with 122...

  3. Fabrication of large-area concave microlens array on silicon by femtosecond laser micromachining.

    Science.gov (United States)

    Deng, Zefang; Yang, Qing; Chen, Feng; Meng, Xiangwei; Bian, Hao; Yong, Jiale; Shan, Chao; Hou, Xun

    2015-05-01

    In this Letter, a novel fabrication of large-area concave microlens array (MLA) on silicon is demonstrated by combination of high-speed laser scanning, which would result in single femtosecond laser pulse ablation on surface of silicon, and subsequent wet etching. Microscale concave microlenses with tunable dimensions and accessional aspherical profile are readily obtained on the 1  cm × 1  cm silicon film, which are useful as optical elements for infrared (IR) applications. The aperture diameter and height of the microlens were characterized and the results reveal that they are both proportional to the laser scanning speed. Moreover, the optical property of high-performance silicon MLAs as a reflective homogenizer was investigated for the visible wavelength, and it can be easily extended to IR light. PMID:25927750

  4. Thermal history of Tattapani area (Narmada-Son lineament) as revealed by fission-track technique

    International Nuclear Information System (INIS)

    Fission-track ages of core samples from boreholes penetrating basement of Tattapani geothermal area reveal a mean age of 36,796 years. The age records the last thermal impulse due to influx of hot meteoric water. (author). 20 refs., 3 figs., 1 tab

  5. Effects of nano-SiO{sub 2} particles on surface tracking characteristics of silicone rubber composites

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yong, E-mail: tjuliuyong@tju.edu.cn; Li, Zhonglei; Du, Boxue [Key Laboratory of Smart Grid of Ministry of Education (Tianjin University), School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China)

    2014-09-08

    Compared with neat silicone rubber composites (SiRCs), SiRCs filled with nano-sized SiO{sub 2} particles at weight ratios from 0.1 to 1.0 wt. % exhibit a higher surface flashover voltage and a greater resistance to surface tracking. Scanning electron microscopy images of tracking morphologies indicate that the SiO{sub 2} particles are situated in close proximity to the polymeric chains and act as bridges to stabilize the chains and maintain the structure of the composite. Higher concentrations of nano-sized SiO{sub 2} particles, however, (above 0.3 wt. %) produce defects in the molecular network which lead to reductions in both the surface flashover voltage and the resistance to surface tracking, although these reduced values are still superior to those of neat SiRCs. Therefore, SiRCs filled with nano-sized SiO{sub 2} particles, especially at an optimal weight ratio (0.1 to 0.3 wt. %), may have significant potential applications as outdoor insulators for power systems.

  6. A large area, silicon photomultiplier-based PET detector module

    Science.gov (United States)

    Raylman, R. R.; Stolin, A.; Majewski, S.; Proffitt, J.

    2014-01-01

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26×58 array of 1.5×1.5 mm2 LYSO elements (spanning 41×91 mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ~45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (~2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3 T clinical magnetic resonance imaging scanner.

  7. A large area, silicon photomultiplier-based PET detector module

    International Nuclear Information System (INIS)

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26×58 array of 1.5×1.5 mm2 LYSO elements (spanning 41×91 mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ∼45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (∼2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3 T clinical magnetic resonance imaging scanner

  8. A liquid-helium cooled large-area silicon PIN photodiode x-ray detector

    OpenAIRE

    Inoue, Yoshizumi; Moriyama, Shigetaka; Hara, Hideyuki; Minowa, Makoto; Shimokoshi, Fumio

    1995-01-01

    An x-ray detector using a liquid-helium cooled large-area silicon PIN photodiode has been developed along with a tailor-made charge sensitive preamplifier whose first-stage JFET has been cooled. The operating temperature of the JFET has been varied separately and optimized. The x- and $\\gamma$-ray energy spectra for an \

  9. The silicon tracking system of the CBM experiment at FAIR. Development of microstrip sensors and signal transmission lines for a low-mass, low-noise system

    International Nuclear Information System (INIS)

    In this thesis, different physical and electrical aspects of silicon microstrip sensors and low-mass multi-line readout cables have been investigated. These silicon microstrip sensors and readout cables will be used in the Silicon Tracking System (STS) of the fixed-target heavy-ion Compressed Baryonic Matter (CBM) experiment which is under development at the upcoming Facility for Antiproton and ion Research (FAIR) in Darmstadt, Germany. The highly segmented low-mass tracking system is a central CBM detector system to resolve the high tracking densities of charged particles originating from beam-target interactions. Considering the low material budget requirement the double-sided silicon microstrip detectors have been used in several planar tracking stations. The readout electronics is planned to be installed at the periphery of the tracking stations along with the cooling system. Low-mass multi-line readout cables shall bridge the distance between the microstrip sensors and the readout electronics. The CBM running operational scenario suggests that some parts of the tracking stations are expected to be exposed to a total integrated particle fluence of the order of 1 x 1014 neq/cm2. After 1 x 1014 neq/cm2 the damaged modules in the tracking stations will be replaced. Thus radiation hard sensor is an important requirement for the sensors. Moreover, to cope with the high reaction rates, free-streaming (triggerless) readout electronics with online event reconstruction must be used which require high signal-to-noise (SNR) ratio (i.e., high signal efficiency, low noise contributions). Therefore, reduction in noise is a major goal of the sensor and cable development. For better insight into the different aspects of the silicon microstrip sensors and multi-line readout cables, the simulation study has been performed using SYNOPSYS TCAD tools. 3D models of the silicon microstrip sensors and the readout cables were implemented which is motivated by the stereoscopic

  10. Sensor-Aware Recognition and Tracking for Wide-Area Augmented Reality on Mobile Phones.

    Science.gov (United States)

    Chen, Jing; Cao, Ruochen; Wang, Yongtian

    2015-01-01

    Wide-area registration in outdoor environments on mobile phones is a challenging task in mobile augmented reality fields. We present a sensor-aware large-scale outdoor augmented reality system for recognition and tracking on mobile phones. GPS and gravity information is used to improve the VLAD performance for recognition. A kind of sensor-aware VLAD algorithm, which is self-adaptive to different scale scenes, is utilized to recognize complex scenes. Considering vision-based registration algorithms are too fragile and tend to drift, data coming from inertial sensors and vision are fused together by an extended Kalman filter (EKF) to achieve considerable improvements in tracking stability and robustness. Experimental results show that our method greatly enhances the recognition rate and eliminates the tracking jitters. PMID:26690439

  11. Influence of track effects on defect distribution in silicon irradiated by 210 MeV krypton ions

    International Nuclear Information System (INIS)

    The second peak in the defect distribution, located beyond the standard one, has been observed into silicon samples, irradiated by krypton ions with an energy 210 MeV. The rate of the second peak amplitude increase is higher with respect to the first one. The amplitude of the second peak exceeds the amplitude of the first peak under the certain influence. This experiment has been explained by the latent tracks formation along the projected range. The phenomenological model of the point defect balance has been developed. The value of the lowered density zone radius and the parameters of the point defect diffusion of the model, which is in an agreement with the existing estimations, have been found. The comparison of the experimental and the calculated distributions of the defects has been performed. 31 refs., 2 figs., 1 tab

  12. Progress in amorphous silicon based large-area multijunction modules

    Science.gov (United States)

    Carlson, D. E.; Arya, R. R.; Bennett, M.; Chen, L.-F.; Jansen, K.; Li, Y.-M.; Maley, N.; Morris, J.; Newton, J.; Oswald, R. S.; Rajan, K.; Vezzetti, D.; Willing, F.; Yang, L.

    1996-01-01

    Solarex, a business unit of Amoco/Enron Solar, is scaling up its a-Si:H/a-SiGe:H tandem device technology for the production of 8 ft2 modules. The current R&D effort is focused on improving the performance, reliability and cost-effectiveness of the tandem junction technology by systematically optimizing the materials and interfaces in small-area single- and tandem junction cells. Average initial conversion efficiencies of 8.8% at 85% yield have been obtained in pilot production runs with 4 ft2 tandem modules.

  13. A Silicon UCN Detector With Large Area and With Analysis of UCN Polarization.

    Science.gov (United States)

    Lasakov, M; Serebrov, A; Khusainov, A; Pustovoit, A; Borisov, Yu; Fomin, A; Geltenbort, P; Kon'kov, O; Kotina, I; Shablii, A; Solovei, V; Vasiliev, A

    2005-01-01

    A silicon ultracold neutron (UCN) detector with an area of 45 cm(2) and with a (6)LiF converter is developed at St. Petersburg Nuclear Physics Institute (PNPI). The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at Institut Max von Laue - Paul Langevin (ILL). The sandwich-type detector from two silicon plates with a (6)LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarization was developed and tested. The analyzing power of this detector assembly reaches up 75 % for the main part of UCN spectrum. This UCN detector with analysis of UCN polarization can be used in the new electric dipole moment (EDM) spectrometer. PMID:27308138

  14. Experience with silicon sensor performance and quality control for a large-area detector

    CERN Document Server

    Krammer, M

    2003-01-01

    The CMS silicon tracker, at present under construction, will consist of 10 barrel layers and 2 multiplied by 9 end cap discs inside a volume of about 5.6 m length and 2.4 m radius. The total sensitive area covered by silicon will exceed 200 m**2. To cope with the expected radiation damage induced by the particle fluence at the Large Hadron Collider the detector will be operated at -10 degree C. Two companies manufacture the 25000 silicon sensors in 15 different geometries. The delivery of the sensors is under way and hence an extensive quality control program for the sensors has been put in operation. The paper gives an overview of the CMS tracker system and subsequently concentrates on the results from the sensor tests. In addition, measurements on dedicated test structures are presented which were designed to monitor the stability of the sensor production process.

  15. Ultra long-range interactions between large area graphene and silicon.

    Science.gov (United States)

    Na, Seung Ryul; Suk, Ji Won; Ruoff, Rodney S; Huang, Rui; Liechti, Kenneth M

    2014-11-25

    The wet-transfer of graphene grown by chemical vapor deposition (CVD) has been the standard procedure for transferring graphene to any substrate. However, the nature of the interactions between large area graphene and target substrates is unknown. Here, we report on measurements of the traction-separation relations, which represent the strength and range of adhesive interactions, and the adhesion energy between wet-transferred, CVD grown graphene and the native oxide surface of silicon substrates. These were determined by coupling interferometry measurements of the separation between the graphene and silicon with fracture mechanics concepts and analyses. The measured adhesion energy was 357 ± 16 mJ/m(2), which is commensurate with van der Waals interactions. However, the deduced traction-separation relation for graphene-silicon interactions exhibited a much longer range interaction than those normally associated with van der Waals forces, suggesting that other mechanisms are present. PMID:25317979

  16. Highly efficient industrial large-area black silicon solar cells achieved by surface nanostructured modification

    Science.gov (United States)

    Li, Ping; Wei, Yi; Zhao, Zengchao; Tan, Xin; Bian, Jiming; Wang, Yuxuan; Lu, Chunxi; Liu, Aimin

    2015-12-01

    Traditional black silicon solar cells show relatively low efficiencies due to the high surface recombination occurring at the front surfaces. In this paper, we present a surface modification process to suppress surface recombination and fabricate highly efficient industrial black silicon solar cells. The Ag-nanoparticle-assisted etching is applied to realize front surface nanostructures on silicon wafers in order to reduce the surface reflectance. Through a further tetramethylammonium hydroxide (TMAH) treatment, the carrier recombination at and near the surface is greatly suppressed, due to a lower surface dopant concentration after the surface modification. This modified surface presents a low reflectivity in a range of 350-1100 nm. Large-area solar cells with an average conversion efficiency of 19.03% are achieved by using the TMAH treatment of 30 s. This efficiency is 0.18% higher than that of standard silicon solar cells with pyramidal surfaces, and also a remarkable improvement compared with black silicon solar cells without TMAH modifications.

  17. Suppression Effect and Mechanism of Platinum and Nitrogen-Containing Silane on the Tracking and Erosion of Silicone Rubber for High-Voltage Insulation.

    Science.gov (United States)

    Chen, Wan Juan; Zeng, Xingrong; Lai, Xuejun; Li, Hongqiang; Fang, Wei Zhen; Hou, Fei

    2016-08-17

    How to effectively improve the tracking and erosion resistance of silicone rubber (SR) was an urgent topic in the field of high-voltage insulation. In this work, the tracking and erosion resistance of SR was significantly improved by incorporating platinum (Pt) catalyst and nitrogen-containing silane (NS). The suppression effect and mechanism of Pt/NS on tracking and erosion were studied by inclined plane (IP) test, thermogravimetry (TG), thermogravimetry-Fourier transform infrared spectrometry, laser Raman spectroscopy, and scanning electron microscopy. It revealed that when 1.4 phr of NS and 6.7 ppm of Pt were added, the tracking resistance of SR was improved from 2.5 to 4.5 kV level in the IP test, and the eroded mass was significantly reduced. This might be attributed to the synergistic effect of Pt/NS on silicone chains. At a high temperature produced by arc discharge, Pt/NS would catalyze radical cross-linking, meanwhile suppressing oxidation and depolymerization of silicone chains. Hence, a tightly cross-linked network was formed and protected inner materials from arc ablation. Moreover, carbon deposit during pyrolysis was suppressed by Pt/NS, which served as the secondary mechanism of tracking suppression. PMID:27462876

  18. Track based alignment of the CMS silicon tracker and its implication on physics performance

    Energy Technology Data Exchange (ETDEWEB)

    Draeger, Jula

    2011-08-15

    In order to fully exploit the discovery potential of the CMS detector for new physics beyond the Standard Model at the high luminosity and centre-of-mass energy provided by the Large Hadron Collider, a careful calibration of the detector and profound understanding of its impact on physics performance are necessary to provide realistic uncertainties for the measurements of physics processes. This thesis describes the track-based alignment of the inner tracking system of CMS with the Millepede II algorithm. Using the combined information of tracks from cosmic rays and collisions taken in 2010, a remarkable local alignment precision has been reached that meets the design specification for most regions of the detector and takes into account instabilities of the detector geometry over time. In addition, the impact of the alignment of b tagging or the Z boson resonance are investigated. The latter is studied to investigate the impact of correlated detector distortions which hardly influence the overall solution of the minimisation problem but introduce biases in the track parameters and thus the derived physics quantities. The determination and constraint of these weak modes present the future challenge of the alignment task at CMS. (orig.)

  19. Track based alignment of the CMS silicon tracker and its implication on physics performance

    International Nuclear Information System (INIS)

    In order to fully exploit the discovery potential of the CMS detector for new physics beyond the Standard Model at the high luminosity and centre-of-mass energy provided by the Large Hadron Collider, a careful calibration of the detector and profound understanding of its impact on physics performance are necessary to provide realistic uncertainties for the measurements of physics processes. This thesis describes the track-based alignment of the inner tracking system of CMS with the Millepede II algorithm. Using the combined information of tracks from cosmic rays and collisions taken in 2010, a remarkable local alignment precision has been reached that meets the design specification for most regions of the detector and takes into account instabilities of the detector geometry over time. In addition, the impact of the alignment of b tagging or the Z boson resonance are investigated. The latter is studied to investigate the impact of correlated detector distortions which hardly influence the overall solution of the minimisation problem but introduce biases in the track parameters and thus the derived physics quantities. The determination and constraint of these weak modes present the future challenge of the alignment task at CMS. (orig.)

  20. The upgrade of the ALICE Inner Tracking System - Status of the R&D; on monolithic silicon pixel sensors

    CERN Document Server

    Van Hoorne, Jacobus Willem

    2014-01-01

    s a major part of its upgrade plans, the ALICE experiment schedules the installation of a novel Inner Tracking System (ITS) during the Long Shutdown 2 (LS2) of the LHC in 2018/19. It will replace the present silicon tracker with seven layers of Monolithic Active Pixel Sensors (MAPS) and significantly improve the detector performance in terms of tracking and rate capabilities. The choice of technology has been guided by the tight requirements on the material budget of 0 : 3 % X = X 0 /layer for the three innermost layers and backed by the significant progress in the field of MAPS in recent years. The pixel chips are manufactured in the TowerJazz 180 nm CMOS imaging sensor process on wafers with a high resistivity epitaxial layer. Within the ongoing R&D; phase, several sensor chip prototypes have been developed and produced on different epitaxial layer thicknesses and resistivities. These chips are being characterized for their performance before and after irradiation using source tests, test beam and measu...

  1. Interference lithographically defined and catalytically etched, large-area silicon nanocones from nanowires.

    Science.gov (United States)

    Dawood, M K; Liew, T H; Lianto, P; Hong, M H; Tripathy, S; Thong, J T L; Choi, W K

    2010-05-21

    We report a simple and cost effective method for the synthesis of large-area, precisely located silicon nanocones from nanowires. The nanowires were obtained from our interference lithography and catalytic etching (IL-CE) method. We found that porous silicon was formed near the Au catalyst during the fabrication of the nanowires. The porous silicon exhibited enhanced oxidation ability when exposed to atmospheric conditions or in wet oxidation ambient. Very well located nanocones with uniform sharpness resulted when these oxidized nanowires were etched in 10% HF. Nanocones of different heights were obtained by varying the doping concentration of the silicon wafers. We believe this is a novel method of producing large-area, low cost, well defined nanocones from nanowires both in terms of the control of location and shape of the nanocones. A wide range of potential applications of the nanocone array can be found as a master copy for nanoimprinted polymer substrates for possible biomedical research; as a candidate for making sharp probes for scanning probe nanolithography; or as a building block for field emitting tips or photodetectors in electronic/optoelectronic applications. PMID:20418606

  2. Vehicle tracking in wide area motion imagery from an airborne platform

    Science.gov (United States)

    van Eekeren, Adam W. M.; van Huis, Jasper R.; Eendebak, Pieter T.; Baan, Jan

    2015-10-01

    Airborne platforms, such as UAV's, with Wide Area Motion Imagery (WAMI) sensors can cover multiple square kilometers and produce large amounts of video data. Analyzing all data for information need purposes becomes increasingly labor-intensive for an image analyst. Furthermore, the capacity of the datalink in operational areas may be inadequate to transfer all data to the ground station. Automatic detection and tracking of people and vehicles enables to send only the most relevant footage to the ground station and assists the image analysts in effective data searches. In this paper, we propose a method for detecting and tracking vehicles in high-resolution WAMI images from a moving airborne platform. For the vehicle detection we use a cascaded set of classifiers, using an Adaboost training algorithm on Haar features. This detector works on individual images and therefore does not depend on image motion stabilization. For the vehicle tracking we use a local template matching algorithm. This approach has two advantages. In the first place, it does not depend on image motion stabilization and it counters the inaccuracy of the GPS data that is embedded in the video data. In the second place, it can find matches when the vehicle detector would miss a certain detection. This results in long tracks even when the imagery is of low frame-rate. In order to minimize false detections, we also integrate height information from a 3D reconstruction that is created from the same images. By using the locations of buildings and roads, we are able to filter out false detections and increase the performance of the tracker. In this paper we show that the vehicle tracks can also be used to detect more complex events, such as traffic jams and fast moving vehicles. This enables the image analyst to do a faster and more effective search of the data.

  3. Pattern recognition of tracks induced by individual quanta of ionizing radiation in Medipix2 silicon detector

    International Nuclear Information System (INIS)

    Medipix2 is a semiconductor pixel detector (256x256 pixels, 55x55 μm2 each) which can count individual quanta of radiation. The detector will respond differently for different types of radiation. If the acquisition time is short enough with respect to radiation intensity, one can see characteristic tracks of individual quanta in an image taken (e.g., curved lines for electrons, round shaped clusters for alpha particles, heavy ions and slow neutrons, cone shapes for fast neutrons, simple dots for low energy X-rays, etc.). For effective visualization of neutrons, the device has to be equipped by corresponding neutron converter, which converts neutrons to heavy charged particles. By analyzing these patterns, in this so-called 'tracking mode' of operation, it is possible to distinguish individual tracks and classify them into predefined categories. For each 'cluster' detected, the features (such as parameters describing the shape and energy deposition estimation) can be extracted and used to distinguish radiation type. The energy deposited can be estimated by using calibration measurements with different types of radiation and variation of the discrimination threshold

  4. Development and operation of tracking detectors in silicon technology for the LHCb upgrade

    CERN Document Server

    Rodriguez Perez, Pablo; Adeva, Bernardo

    The LHCb experiment is one of the four main experiments at the Large Hadron Collider (LHC) at CERN. It uses the energy density provided by the LHC to attempt to probe asymmetries between particles and antiparticles that can not be explained by the Standard Model, and thus provide evidence that would allow us to build a new model of fundamental physics. This thesis covers the author's work in the Silicon Tracker $(\\textit{ST})$ and VErtex LOcator $(\\textit{VELO})$ detectors of the LHCb experiment. The thesis explains the installation and commissioning of the $ST$, as well as the development of the slow control for the detector. The $ST$ is a silicon micro-strip detector which provides precise momentum measurements of ionizing particles coming from the collisions. The $ST$consists of two sub-detectors: the Tracker Turicensis $ (TT)$, located upstream of the 4 Tm dipole magnet covering the full acceptance of the experiment, and the Inner Tracker $(IT)$, which covers the region of highest particle density closest...

  5. The silicon tracker/converter for the gamma-ray large area space telescope

    International Nuclear Information System (INIS)

    The Silicon Tracker/Converter of the Gamma-ray Large Area Space Telescope (GLAST) will have an active area of 80 m2, representing one of the largest planned applications of the silicon-strip detector technology. The large number of channels (1.3 million) to read out, together with the requirement that the tracker provide the trigger to the data acquisition, force the readout electronics to be of very low noise. Furthermore, to fit into the power constraints of the satellite environment, the electronics must have an ultra-low power consumption. To fulfill these requirements, plus others imposed by the space environment, such as redundancy, a mixed mode CMOS front-end readout chip and a digital readout controller chip have been designed and prototyped. In this article, we present the status of the readout electronics and the results from a test-beam study with a small GLAST tracker prototype. (author)

  6. A liquid-helium cooled large-area silicon PIN photodiode X-ray detector

    International Nuclear Information System (INIS)

    An X-ray detector using a liquid-helium cooled large-area silicon PIN photodiode has been developed along with a tailor-made charge sensitive preamplifier whose first-stage JFET has been cooled. The operating temperature of the JFET has been varied separately and optimized. The X- and γ-ray energy spectra for an 241Am source have been measured with the photodiode operated at 13 K. An energy resolution of 1.60 keV (FWHM) has been obtained for 60-keV γ rays and 1.30 keV (FWHM) for the pulser. The energy threshold could be set as low as 3 keV. It has been shown that a silicon PIN photodiode serves as a low-cost excellent X-ray detector which covers a large area at 13 K. (orig.)

  7. Large area silicon drift detectors for x-rays -- New results

    International Nuclear Information System (INIS)

    Large area silicon drift detectors, consisting of 8 mm and 12 mm diameter hexagons, were fabricated on 0.35 mm thick high resistivity n-type silicon. An external FET and a low-noise charge sensitive preamplifier were used for testing the prototype detectors. The detector performance was measured in the range 75 to 25 C using Peltier cooling, and from 0.125 to 6 micros amplifier shaping time. Measured energy resolutions were 159 eV FWHM and 263 eV FWHM for the 0.5 cm2 and 1 cm2 detectors, respectively (at 5.9 keV, -75 C, 6 micros shaping time). The uniformity of the detector response over the entire active area (measured using 560 nm light) was < 0.5%

  8. Application of large area silicon-silicon-plastic detectors for heavy-ion detection

    International Nuclear Information System (INIS)

    To study binary and multibody breakup reactions at intermediate energies (20-100 MeV/u), a 48 element multiplicity array has been designed for reverse kinematic reactions. In reverse kinematics the reaction products are emitted at about beam energy and are focused into a forward cone in the laboratory frame. Each telescope is composed of a 300μm Si, a 5mm Si(Li) and a 7.6cm plastic detector. The geometry of the array is a 7 x 7 wall placed in front of the beam, omitting the center position, which can arc in one dimension. To detect multibody events in the array with good efficiency, the telescopes are designed for close packing and with a 64% active area. These three stage telescopes will be able to detect particles with energies from 1-150 MeV/u, and identify fragments with Z = 2-60 and E/A = 10-100 MeV/u using the ΔE-E technique

  9. Simulation-Based Optimization of Cure Cycle of Large Area Compression Molding for LED Silicone Lens

    OpenAIRE

    Min-Jae Song; Kwon-Hee Kim; Seok-Kwan Hong; Jeong-Won Lee; Jeong-Yeon Park; Gil-Sang Yoon; Heung-Kyu Kim

    2015-01-01

    Three-dimensional heat transfer-curing simulation was performed for the curing process by introducing a large area compression molding for simultaneous forming and mass production for the lens and encapsulants in the LED molding process. A dynamic cure kinetics model for the silicone resin was adopted and cure model and analysis result were validated and compared through a temperature measurement experiment for cylinder geometry with cure model. The temperature deviation between each lens cav...

  10. Tracks FAQs: How Can I Tell If Asthma Hospitalization Rates In My Area Are Changing Over Time?

    Centers for Disease Control (CDC) Podcasts

    2011-06-07

    In this podcast, CDC Tracking experts discuss asthma hospitalization rates and how you can tell if they've changed in your area over time. Do you have a question for our Tracking experts? Please e-mail questions to trackingsupport@cdc.gov.  Created: 6/7/2011 by National Center for Environmental Health, Division of Environmental Hazards and Health Effects, Environmental Health Tracking Branch.   Date Released: 6/7/2011.

  11. A Novel System for Non-Invasive Method of Animal Tracking and Classification in Designated Area Using Intelligent Camera System

    OpenAIRE

    S. Matuska; Hudec, R.; P. Kamencay; M. Benco; M. Radilova

    2016-01-01

    This paper proposed a novel system for non-invasive method of animal tracking and classification in designated area. The system is based on intelligent devices with cameras, which are situated in a designated area and a main computing unit (MCU) acting as a system master. Intelligent devices track animals and then send data to MCU to evaluation. The main purpose of this system is detection and classification of moving animals in a designated area and then creation of migration corridors of wi...

  12. Increase in the area of etched alpha-particle tracks in CR-39 plastic with increasing storage time under nitrogen

    CERN Document Server

    Bhakta, J R; Miles, J C H

    1999-01-01

    The area of etched tracks in CR-39 (polyallyl diglycol carbonate, PADC) exposed to alpha-particles from an americium-241 source has been investigated as a function of post-exposure storage time in a dry nitrogen atmosphere. Data were collected over 2.5 years and the results show that the nominal maximum area of the track area distribution increases with increasing storage time.

  13. Rippled area formed by surface plasmon polaritons upon femtosecond laser double-pulse irradiation of silicon.

    Science.gov (United States)

    Derrien, Thibault J-Y; Krüger, Jörg; Itina, Tatiana E; Höhm, Sandra; Rosenfeld, Arkadi; Bonse, Jörn

    2013-12-01

    The formation of near-wavelength laser-induced periodic surface structures (LIPSS) on silicon upon irradiation with sequences of Ti:sapphire femtosecond laser pulse pairs (pulse duration 150 fs, central wavelength 800 nm) is studied theoretically. For this purpose, the nonlinear generation of conduction band electrons in silicon and their relaxation is numerically calculated using a two-temperature model approach including intrapulse changes of optical properties, transport, diffusion and recombination effects. Following the idea that surface plasmon polaritons (SPP) can be excited when the material turns from semiconducting to metallic state, the "SPP active area" is calculated as function of fluence and double-pulse delay up to several picoseconds and compared to the experimentally observed rippled surface areas. Evidence is presented that multi-photon absorption explains the large increase of the rippled area for temporally overlapping pulses. For longer double-pulse delays, relevant relaxation processes are identified. The results demonstrate that femtosecond LIPSS on silicon are caused by the excitation of SPP and can be controlled by temporal pulse shaping. PMID:24514516

  14. Closure Report for Corrective Action Unit 486: Double Tracks RADSAFE Area Nellis Air Force Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    D. H. Cox

    2000-12-01

    The Double Tracks Radiological Safety Area (DTRSA), Corrective Action Unit (CAU) 486, was clean-closed following the approved Corrective Action Decision Document closure alternative and in accordance with the Federal Facility Agreement and Consent Order. The CAU consists of a single Corrective Action Site, 71-23-001-71DT. The DTRSA was used during May 1963 to decontaminate vehicles, equipment, personnel and animals from the Double Tracks Test. Double Tracks was one of four storage-transportation tests. The Double Tracks test was conducted in Stonewall Flat, approximately 32 kilometers (20 miles) east of Goldfield, Nevada, on the Nellis Air Force Range. The Double Tracks Test used a single device containing plutonium and depleted uranium and was designed to investigate the characteristics of plutonium-bearing particulate material formed by the non-nuclear detonation of a nuclear weapon. All facilities associated with the DTRSA operation were removed. Based on available information, the areas of concern at the DTRSA consisted of a decon facility (vehicle decon pad and decon sump) in the southern half of the DTRSA, and a burial pit and former loading/unloading area located in the northern half of the DTRSA. Based on the results of the Corrective Action Investigation, radiological field screening detected elevated gamma and alpha readings on excavated plastic debris. Swipe surveys taken on the plastic debris detected removable alpha. No contaminants were detected above preliminary action levels in soil samples. The debris excavated during the corrective action investigation was not characterized. The clean-closure corrective action consisted of excavation, disposal, verification sampling, backfilling, and regrading. Field activities began on May 1, 2000, and ended on May 10, 2000. Soil that was associated with the radiologically contaminated man-made debris was placed into B-25 bins, moved to the designated waste management area where it was scanned, and hauled off

  15. Closure Report for Corrective Action Unit 486: Double Tracks RADSAFE Area Nellis Air Force Range, Nevada

    International Nuclear Information System (INIS)

    The Double Tracks Radiological Safety Area (DTRSA), Corrective Action Unit (CAU) 486, was clean-closed following the approved Corrective Action Decision Document closure alternative and in accordance with the Federal Facility Agreement and Consent Order. The CAU consists of a single Corrective Action Site, 71-23-001-71DT. The DTRSA was used during May 1963 to decontaminate vehicles, equipment, personnel and animals from the Double Tracks Test. Double Tracks was one of four storage-transportation tests. The Double Tracks test was conducted in Stonewall Flat, approximately 32 kilometers (20 miles) east of Goldfield, Nevada, on the Nellis Air Force Range. The Double Tracks Test used a single device containing plutonium and depleted uranium and was designed to investigate the characteristics of plutonium-bearing particulate material formed by the non-nuclear detonation of a nuclear weapon. All facilities associated with the DTRSA operation were removed. Based on available information, the areas of concern at the DTRSA consisted of a decon facility (vehicle decon pad and decon sump) in the southern half of the DTRSA, and a burial pit and former loading/unloading area located in the northern half of the DTRSA. Based on the results of the Corrective Action Investigation, radiological field screening detected elevated gamma and alpha readings on excavated plastic debris. Swipe surveys taken on the plastic debris detected removable alpha. No contaminants were detected above preliminary action levels in soil samples. The debris excavated during the corrective action investigation was not characterized. The clean-closure corrective action consisted of excavation, disposal, verification sampling, backfilling, and regrading. Field activities began on May 1, 2000, and ended on May 10, 2000. Soil that was associated with the radiologically contaminated man-made debris was placed into B-25 bins, moved to the designated waste management area where it was scanned, and hauled off

  16. Advances in silicon detectors for particle tracking in extreme radiation environments

    CERN Document Server

    Parker, Sherwood; Da Vià, C; Hasi, J; Jarron, Pierre; Kenney, C; Kok, A; Perozziello, E; Watts, S J

    2003-01-01

    The LHC (Large Hadron Collider) is currently under construction at CERN, the European Laboratory for Particle Physics based in Geneva. The experiments at this accelerator will use substantial numbers of silicon detectors. These are close to the interaction point and will be exposed to very high fluences ( up to 10**1**5 particles cm**-**2) during their operating life. Such detectors are crucial to the disentanglement of important decay events and it is vital to guarantee a homogeneous reliable performance during their operation. Parameters like the charge collection efficiency (CCE) and response time will be discussed. Limitations of present technologies will be analysed and future strategies explored. Results obtained using alternative detector designs, such as 3D geometry, material engineering by oxygen diffusion and unconventional operational conditions are surveyed.

  17. SALT, a dedicated readout chip for high precision tracking silicon strip detectors at the LHCb Upgrade

    Science.gov (United States)

    Bugiel, Sz.; Dasgupta, R.; Firlej, M.; Fiutowski, T.; Idzik, M.; Kuczynska, M.; Moron, J.; Swientek, K.; Szumlak, T.

    2016-02-01

    The Upstream Tracker (UT) silicon strip detector, one of the central parts of the tracker system of the modernised LHCb experiment, will use a new 128-channel readout ASIC called SALT. It will extract and digitise analogue signals from the UT sensors, perform digital signal processing and transmit a serial output data. The SALT is being designed in CMOS 130 nm process and uses a novel architecture comprising of analog front-end and fast (40 MSps) ultra-low power (<0.5 mW) 6-bit ADC in each channel. The prototype ASICs of important functional blocks, like analogue front-end, 6-bit SAR ADC, PLL, and DLL, were designed, fabricated and tested. A prototype of an 8-channel version of the SALT chip, comprising all important functionalities was also designed and fabricated. The architecture and design of the SALT, together with the selected preliminary tests results, are presented.

  18. tkLayout: a Design Tool for Innovative Silicon Tracking Detectors

    CERN Document Server

    Bianchi, Giovanni

    2014-01-01

    A new CMS tracker is scheduled to become operational for the LHC Phase 2 upgrade in the early 2020's. tkLayout is a software package developed to create 3d models for the design of the CMS tracker and to evaluate its fundamental performance figures. The new tracker will have to cope with much higher luminosity conditions, resulting in increased track density, harsher radiation exposure and, especially, much higher data acquisition bandwidth, such that equipping the tracker with triggering capabilities is envisaged. The design of an innovative detector involves deciding on an architecture offering the best trade-off among many figures of merit, such as tracking resolution, power dissipation, bandwidth, cost and so on. Quantitatively evaluating these figures of merit as early as possible in the design phase is of capital importance and it is best done with the aid of software models. tkLayout is a flexible modeling tool: new performance estimates and support for different detector geometries can be quickly ad...

  19. Microcrystalline silicon deposited at high rate on large areas from pure silane with efficient gas utilization

    Energy Technology Data Exchange (ETDEWEB)

    Strahm, B.; Howling, A.A.; Sansonnens, L.; Hollenstein, C. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Kroll, U.; Meier, J.; Ellert, Ch. [Oerlikon Solar-Lab, Rue du Puits-Godet 12a, CH-2000 Neuchatel (Switzerland); Feitknecht, L.; Ballif, C. [Institut de Microtechnique, Universite de Neuchatel, Rue A.-L. Breguet 2, CH-2000 Neuchatel (Switzerland)

    2007-03-23

    Microcrystalline silicon thin film deposited by RF-PECVD and integrated in a tandem structure is a promising material for low cost photovoltaic solar cells compared to solar cells based on crystalline silicon. However, in order to allow a cost-effective mass production of solar cells based on this material, deposition processes should fulfill several conditions such as high deposition rate, good uniformity over large area and efficient gas utilization. In this work, it is shown that the atomic hydrogen density can be high enough to form microcrystalline thin films even from a pure silane RF discharge and that the pure silane regime is more efficient in terms of gas utilization. In situ Fourier transform infrared absorption and ex situ Raman spectroscopy measurements have been used to determine the fraction of dissociated silane in the discharge and the crystallinity of the deposited layers. Results have shown that microcrystalline silicon can be deposited uniformly on a large area substrate with a deposition rate of more than 10A with a low powder formation and an input power density of 0.28Wcm{sup -2} from a pure silane discharge. (author)

  20. Demonstration of lasercom and spatial tracking with a silicon Geiger-mode APD array

    Science.gov (United States)

    Yarnall, Timothy M.; Horkley, Benjamin W.; Garg, Ajay S.; Hamilton, Scott A.

    2016-03-01

    We present a demonstration of a high-rate photon counting receiver with the potential to act as a spatial tracker based on a silicon Geiger-mode avalanche photodiode array (GM-APD). This array enables sensitive high-rate optical communication in the visible and near infrared regions of the spectrum. The array contains 1024 elements arranged in a 32x32 pixel square. This large number of elements supports high data rates through the mitigation of blocking losses and associated data rate limitations created by the reset time of an individual Geiger-mode detector. Measurement of bit error rates demonstrate that receiver sensitivities of 2.55 dB (detected) photons-per-bit for 78.8 Mb/s on-off-keying and -0.46 dB (detected) photons-per-bit for 19.4 Mb/s 16-ary pulse-position modulation are accessible with strong forward error correction. Additionally, the array can record the spatial coordinates of each detection event. By computing the centroid of the distribution of spatial detections it is possible to determine the angle-of-arrival of the detected photons. These levels of performance imply that Si GM-APD arrays are excellent candidates for a variety of free space lasercom applications ranging from atmospheric communication in the 1 micron or 780 nm spectral windows to underwater communication in the 480 nm to 520 nm spectral window

  1. Biocompatible fluorescent silicon nanocrystals for single-molecule tracking and fluorescence imaging.

    Science.gov (United States)

    Nishimura, Hirohito; Ritchie, Ken; Kasai, Rinshi S; Goto, Miki; Morone, Nobuhiro; Sugimura, Hiroyuki; Tanaka, Koichiro; Sase, Ichiro; Yoshimura, Akihiko; Nakano, Yoshitaro; Fujiwara, Takahiro K; Kusumi, Akihiro

    2013-09-16

    Fluorescence microscopy is used extensively in cell-biological and biomedical research, but it is often plagued by three major problems with the presently available fluorescent probes: photobleaching, blinking, and large size. We have addressed these problems, with special attention to single-molecule imaging, by developing biocompatible, red-emitting silicon nanocrystals (SiNCs) with a 4.1-nm hydrodynamic diameter. Methods for producing SiNCs by simple chemical etching, for hydrophilically coating them, and for conjugating them to biomolecules precisely at a 1:1 ratio have been developed. Single SiNCs neither blinked nor photobleached during a 300-min overall period observed at video rate. Single receptor molecules in the plasma membrane of living cells (using transferrin receptor) were imaged for ≥10 times longer than with other probes, making it possible for the first time to observe the internalization process of receptor molecules at the single-molecule level. Spatial variations of molecular diffusivity in the scale of 1-2 µm, i.e., a higher level of domain mosaicism in the plasma membrane, were revealed. PMID:24043702

  2. Fission track dating of the Cenozoic uplift in Mabian area, southern Sichuan Province, China

    Institute of Scientific and Technical Information of China (English)

    AN YanFen; HAN ZhuJun; WAN JingLin

    2008-01-01

    The apparent ages of samples are obtained from fission track dating of apatite samples collected from the fault zones in Mabian area, southern Sichuan Province.In addition, thermal history is simulated from the obtained data by applying AFTSolve Program, to acquire the thermal evolution history of the samples.The result shows that tectonically the Mabian area was relatively stable between 25 and 3 Ma, compared to the inner parts and other marginal areas of the Tibetan Plateau.The studied area had little response to the rapid uplift events that occurred for several times in the Tibetan Plateau during 25-3 Ma.The latest thermal event related to the activity of the Lidian fault zone (about 8 Ma) is later than that of the Ebian fault zone (18-15 Ma ) to the west, indicating to some extent that the evolution of fault activity in the Mabian area has migrated from west to east.The latest extensive tectonic uplift occurred since about 3 Ma.As compared with the Xianshuihe fault zone, the Mabian area is closer to the eastern margin of the plateau, while the time of fast cooling event in this area is later than that in the southeast segment of the Xianshuihe fault zone (3.6-3.46 Ma).It appears to support the assumption of episodic uplift and stepwise outward extension of the eastern boundary of the Tibetan Plateau in late Cenozoic.

  3. Tracking hydrothermal feature changes in response to seismicity and deformation at Mud Volcano thermal area, Yellowstone

    Science.gov (United States)

    Diefenbach, A. K.; Hurwitz, S.; Murphy, F.; Evans, W.

    2013-12-01

    The Mud Volcano thermal area in Yellowstone National Park comprises many hydrothermal features including fumaroles, mudpots, springs, and thermal pools. Observations of hydrothermal changes have been made for decades in the Mud Volcano thermal area, and include reports of significant changes (the appearance of new features, increased water levels in pools, vigor of activity, and tree mortality) following an earthquake swarm in 1978 that took place beneath the area. However, no quantitative method to map and measure surface feature changes through time has been applied. We present an analysis of aerial photographs from 1954 to present to track temporal changes in the boundaries between vegetated and thermally barren areas, as well as location, extent, color, clarity, and runoff patterns of hydrothermal features within the Mud Volcano thermal area. This study attempts to provide a detailed, long-term (>50 year) inventory of hydrothermal features and change detection at Mud Volcano thermal area that can be used to identify changes in hydrothermal activity in response to seismicity, uplift and subsidence episodes of the adjacent Sour Creek resurgent dome, or other potential causes.

  4. Large-area 2D periodic crystalline silicon nanodome arrays on nanoimprinted glass exhibiting photonic band structure effects

    International Nuclear Information System (INIS)

    Two-dimensional silicon nanodome arrays are prepared on large areas up to 50 cm2 exhibiting photonic band structure effects in the near-infrared and visible wavelength region by downscaling a recently developed fabrication method based on nanoimprint-patterned glass, high-rate electron-beam evaporation of silicon, self-organized solid phase crystallization and wet-chemical etching. The silicon nanodomes, arranged in square lattice geometry with 300 nm lattice constant, are optically characterized by angular resolved reflection measurements, allowing the partial determination of the photonic band structure. This experimentally determined band structure agrees well with the outcome of three-dimensional optical finite-element simulations. A 16% photonic bandgap is predicted for an optimized geometry of the silicon nanodome arrays. By variation of the duration of the selective etching step, the geometry as well as the optical properties of the periodic silicon nanodome arrays can be controlled systematically. (paper)

  5. Large-Area Synthesis and Microstructural Investigations of Silicon Nano wires and Core-Shell Structures

    International Nuclear Information System (INIS)

    Large-area randomly-oriented silicon nano wires (SiNWs) were synthesized using Au-coated p-type Si(100) substrate via the solid-liquid-solid (SLS) process [1] under different growth conditions. Microstructural studies on the NWs produced show that straight crystalline nano wires of large aspect ratios were generally obtained at a growth temperature of 1000 degree Celsius along with some worm-like amorphous structures. Figure shows the SEM image of a NW sample. Typical high angle X-ray diffractogram in Figure reveals that the NWs are, in general, crystalline. (author)

  6. Characterization of large area, thick, and segmented silicon detectors for neutron β-decay experiments

    International Nuclear Information System (INIS)

    The “Nab” and “UCNB” collaborations have proposed to measure the correlation parameters in neutron β-decay at Oak Ridge and Los Alamos National Laboratory, using a novel detector design. Two large area, thick, hexagonal-segmented silicon detectors containing 127 pixels per detector will be used to detect the proton and electron from neutron decay. Both silicon detectors are connected by magnetic field lines of a few Tesla field strength, and set on an electrostatic potential, such that protons can be accelerated up to 30 keV in order to be detected. Characteristics of the detector response to low energy conversion electrons and protons from 15 keV to 35 keV, including the evaluation of the dead layer thickness and other contributions to the pulse height defect for proton detection are presented for Si detectors of 0.5 mm and 1 mm of thickness. -- Highlights: • We characterized large area (108 cm2), thick (0.5, 1 mm), and 127-segmented Si detectors. • We detected low energy protons from 15 to 35 keV with these large area Si detectors. • The recombination defect is insignificant at Ep<35keV, for appropriate bias voltages. • Our computed nuclear pulse height defect agrees with available experimental data. • Our detector dead layer is ≲110nm, as probed by low energy protons

  7. Seasonal prediction of typhoon genesis frequency and track patterns in the North West Pacific area

    Science.gov (United States)

    Hyoun, Yoosun; Kang, Kiryong; Shin, Do-Shick

    2014-05-01

    This study is to investigate the performance of the typhoon seasonal predictability using a dynamical model. The check items are the monthly statistics for total number of typhoon genesis in Western North Pacific (WNP) area and possible threat to Korean peninsula among them, and the probability of each categorized track pattern. As the dynamical model the Florida State University/Center for Ocean-Atmospheric Prediction Studies (FSU/COAPS) was used, and it uses five ensemble members including control run are generated using time-lagged methods and the resolution of T126L27 (a Gaussian grid spacing of 0.94º). The model initial conditions are obtained from the National Center for Enviromental Prediction Global Forecast System (NCEP GFS) and the SST from Climate Forecast System with bias correction was used for ocean surface boundary condition. The summer (Jun-Jul-Aug) season prediction is made one month prior to target season. The detection of tropical cyclone used in this system is based on six criteria. First, the isolated vortex type minimum sea level pressure should be below 1008hPa. Second, the maximum wind speed is larger than 17m s-1. Third, the magnitude of the maximum relative vorticity at 850hPa exceeds 3.5x10-5s-1. Fourth, the average temperature difference from the area mean of surrounding region at 300hPa, 500hPa, 700hPa exceeds 2.5K. Fifth, the maximum wind speed at 850hPa is larger than that at 300hPa. Sixth, this identified vortex should last more than two days. These criteria were chosen after close examination from model-observation comparison. In this study, we will focus on performance of the system typhoon frequency and track pattern in the WNP area during 2004-2013.

  8. Characterization of silicon microstrip sensors, front-end electronics, and prototype tracking detectors for the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Sorokin, Iurii

    2013-07-01

    The Compressed Baryonic Matter (CBM) experiment will explore the phase diagram of strongly interacting matter in the region of high net baryonic densities. The matter at the extreme conditions will be studied in collisions of a heavy ion beam with a fixed heavy element target. The present work is devoted to the development of the main component of the CBM experiment - the Silicon Tracking System (STS). The STS has to enable reconstruction of up to 1000 charged particle tracks per nucleus-nucleus interaction at the rate of up to 10 MHz, provide a momentum resolution Δp/p of 1 %, and withstand the radiation load of up to 10{sup 14} n{sub eq}/cm{sup 2} (n{sub eq}-neutron equivalent). The STS will be based on double-sided silicon microstrip sensors, that will be arranged in 8 planes in the aperture of the dipole magnet. Selftriggering readout electronics will be located on the periphery of the detecting planes, and connected to the sensors with low mass microcables. In the stage of R and D, as well as in the stages of pre-series and series production, characterization of the sensors, of the front-end electronics, and of the complete detector modules has to be performed. In the present work the required techniques were developed, and the performance of the latest detector prototypes was evaluated. A particular attention is paid to evaluation of the signal amplitude, as it is one of the most important detector characteristics. Techniques for measuring the passive electrical characteristics of the sensors were developed. These include: the coupling and the interstrip capacitances, the interstrip resistance, the bias resistance, the strip leakage current, the bulk capacitance, and the bulk leakage current. The techniques will be applied for the quality assurance of the sensors during the pre-series and the series production. Extensive characterization of the prototype readout chip, n-XYTER, was performed. The register settings were optimized, and the dependence of the

  9. Understanding the uplift pattern in Mesozoic and Cenozoic,, eastern Dabie area, China using fission track dating of apatite

    International Nuclear Information System (INIS)

    By using the fission track dating technique, a preliminary study was carried out on the fission track ages (FTA) of apatite, their distribution patterns and hints over the tectonics activities during Mesozoic and Cenozoic in the east Dabie area. Attempts were also made to improve the conventional statistical method for the tracks. Ranging from 59.4 +- 3.4 Ma to 105.6 +- 9.8 Ma, the FTA results of apatite spread in the wide range and increased rapidly from the east to the west area. Sine 95 Ma, the uplift rate has been quite slow and asymmetry. The FTA value in the middle area of Xiaotian-Mozitan Fault may imply its uplift in Cretaceous. The faulting should be the main control factor for the uplift of this area

  10. Fabrication of large area silicon solar cells by rapid thermal processing

    Science.gov (United States)

    Sivoththaman, S.; Laureys, W.; Nijs, J.; Mertens, R.

    1995-10-01

    Large area n+pp+ solar cells have been fabricated on 10 cm×10 cm pseudo-quasi-square CZ silicon wafers (1 Ω cm, p-type) predominantly used by the photovoltaic (PV) industry. All the high-temperature steps have been performed by rapid thermal processing (RTP). Emitter formation, back surface field (BSF) formation, and surface oxidation have been performed in just two RTP steps each lasting 50 s. Solar cells of 15% efficiency have been fabricated this way, demonstrating the applicability of this low thermal budget technology to large area, modulable size, industrial quality Si wafers. Furthermore, the rapid thermal oxidation (RTO) is shown to result in good quality thin oxides with Si/SiO2 interface trap densities (Dit)<1011 cm-3 eV-1 near-midgap.

  11. Photon counting pixel and array in amorphous silicon technology for large area digital medical imaging applications

    Science.gov (United States)

    Yazdandoost, Mohammad Y.; Shin, Kyung W.; Safavian, Nader; Taghibakhsh, Farhad; Karim, Karim S.

    2010-04-01

    A single photon counting Voltage Controlled Oscillator (VCO) based pixel architecture in amorphous silicon (a-Si) technology is reported for large area digital medical imaging. The VCO converts X-ray generated input charge into an output oscillating frequency signal. Experimental results for an in-house fabricated VCO circuit in a-Si technology are presented and external readout circuits to extract the image information from the VCO's frequency output are discussed. These readout circuits can be optimized to reduce the fixed pattern noise and fringing effects in an imaging array containing many such VCO pixels. Noise estimations, stability simulations and measurements for the fabricated VCO are presented. The reported architecture is particularly promising for large area photon counting applications (e.g. low dose fluoroscopy, dental computed tomography (CT)) due to its very low input referred electronic noise, high sensitivity and ease of fabrication in low cost a-Si technology.

  12. Laboratory and test beam results from a large-area silicon drift detector

    International Nuclear Information System (INIS)

    A very large-area (6.75x8 cm2) silicon drift detector with integrated high-voltage divider has been designed, produced and fully characterised in the laboratory by means of ad hoc designed MOS injection electrodes. The detector is of the 'butterfly' type, the sensitive area being subdivided into two regions with a maximum drift length of 3.3 cm. The device was also tested in a pion beam (at the CERN PS) tagged by means of a microstrip detector telescope. Bipolar VLSI front-end cells featuring a noise of 250 e- rms at 0 pF with a slope of 40 e-/pF have been used to read out the signals. The detector showed an excellent stability and featured the expected characteristics. Some preliminary results will be presented.

  13. Silicon oxide nanowires: facile and controlled large area fabrication of vertically oriented silicon oxide nanowires for photoluminescence and sensor applications.

    Science.gov (United States)

    Alabi, Taiwo R; Yuan, Dajun; Bucknall, David; Das, Suman

    2013-09-25

    We describe a technique for the fabrication of dense and patterned arrays of aligned silicon oxide nanowires for applications in surface modification, optoelectronic, and electromechanical based devices. Conventional techniques for the fabrication of silicon oxide nanowires based on the vapor-liquid-solid (VLS) chemical vapor deposition (CVD) processes involve the use of high temperatures and catalysts. We demonstrate a technique that extends the use of a plasma thermal reactive ion etching for the fabrication of aligned silicon oxide nanowires with aspect ratios extending up to 20 and lengths exceeding 1 μm. The process incorporates phase separated PS-b-P4VP block copolymer loaded with an iron salt. The iron salt preferentially segregates into the P4VP layer and during an O2 etch is not removed but forms a hexagonally packed array on the silicon oxide substrate. Further etching with CHF3/O2 gas mixture over time can generate nanodots, to nanopillars, and then nanowires of silicon oxide. The photoluminescence property of the as-fabricated nanowire arrays as well as the parasitic ferromagnetic effect from the iron oxide-tipped section of the wires resulting in coalescence under an scanning electron microscope (SEM) are demonstrated. This technique is simpler compared to existing VLS fabrication approaches and can be used for the direct fabrication of patterned arrays of nanowires when a laser interference ablation step is incorporated into the fabrication procedure. PMID:23915216

  14. Robust background subtraction for automated detection and tracking of targets in wide area motion imagery

    Science.gov (United States)

    Kent, Phil; Maskell, Simon; Payne, Oliver; Richardson, Sean; Scarff, Larry

    2012-10-01

    Performing persistent surveillance of large populations of targets is increasingly important in both the defence and security domains. In response to this, Wide Area Motion Imagery (WAMI) sensors with Wide FoVs are growing in popularity. Such WAMI sensors simultaneously provide high spatial and temporal resolutions, giving extreme pixel counts over large geographical areas. The ensuing data rates are such that either very bandwidth data links are required (e.g. for human interpretation) or close-to-sensor automation is required to down-select salient information. For the latter case, we use an iterative quad-tree optical-flow algorithm to efficiently estimate the parameters of a perspective deformation of the background. We then use a robust estimator to simultaneously detect foreground pixels and infer the parameters of each background pixel in the current image. The resulting detections are referenced to the coordinates of the first frame and passed to a multi-target tracker. The multi-target tracker uses a Kalman filter per target and a Global Nearest Neighbour approach to multi-target data association, thereby including statistical models for missed detections and false alarms. We use spatial data structures to ensure that the tracker can scale to analysing thousands of targets. We demonstrate that real-time processing (on modest hardware) is feasible on an unclassified WAMI infra-red dataset consisting of 4096 by 4096 pixels at 1Hz simulating data taken from a Wide FoV sensor on a UAV. With low latency and despite intermittent obscuration and false alarms, we demonstrate persistent tracking of all but one (low-contrast) vehicular target, with no false tracks.

  15. Tracking Fasciola hepatica transmission using ND1 and CO1 gene polimorphisms in endemic areas

    International Nuclear Information System (INIS)

    An initiative to reduce the high burden of human infection by Fasciola hepatica of population of endemic areas has been recently launched in Andean countries such as Peru and Bolivia as part of a collaborative effort of WHO and Health authorities in these countries. In order to reduce the risk of re-infection in areas under control programs for human infection and to diminish the negative impact on productivity on animals, it is necessary to analyze the transmission pattern in endemic areas where the parasite is infecting a variety of species such as cattle, sheep, equine, swine, lagomorphs and rodents. Genetic diversity from a F. hepatica population from an endemic region in Peru (La Encanada - Cajamarca) was analyzed by automated DNA sequencing of the variable fragment of ND1 gene (175 bp) and CO1 gene (216 bp). F. hepatica adult parasites were collected from naturally infected sheep, pig and cattle. Three variable sites for ND1 gene (1.71%) and 4 variable sites for CO1 gene (1.85%) were observed in the parasite population sample. Parasite infecting different species (sheep, pig and cattle) showed four different haplotypes for each gene. Non private specie-specific haplotypes associated to species host were observed. Preliminary results show that Fasciola hepatica populations in Cajamarca - Peru are distributed in three major groups that might be useful to track transmission patterns of this parasite

  16. The LHCb silicon tracker

    CERN Document Server

    Adeva, B; Bauer, C; Baumeister, D; Bay, A; Bernhard, R P; Bernet, R; Blouw, J; Carron, B; Ermoline, Y; Esperante-Pereira, D; Frei, R; Gassner, J; Hofmann, W; Jiménez-Otero, S; Knöpfle, K T; Köstner, S; Lehner, F; Löchner, S; Lois, C; Needham, M; Pugatch, V; Schmelling, M; Schwingenheuer, B; Siegler, M; Steinkamp, O; Straumann, U; Tran, M T; Vázquez, P; Vollhardt, A; Volyanskyy, D; Voss, H

    2005-01-01

    LHCb is a dedicated B-physics and CP-violation experiment for the Large Hadron Collider at CERN. Efficient track reconstruction and excellent trigger performances are essential in order to exploit fully its physics potential. Silicon strip detectors providing fast signal generation, high resolution and fine granularity are used for this purpose in the large area Trigger Tracker station in front of the spectrometer magnet and the LHCb Inner Tracker covering the area close to the beam pipe behind the magnet. Long read-out strips of up to 38cm are used together with fast signal shaping adapted to the 25ns LHC bunch crossing. The design of these tracking stations, the silicon sensor strip geometries and the latest test results are presented here.

  17. On the evening of June 15, 2008, ALICE physicists saw the first tracks at LHC during the first injection test in transfer line TI 2. The Silicon Pixel detector recorded muon tracks produced in the beam dump near Point 2 of the LHC.

    CERN Multimedia

    Manzari, Vito

    2008-01-01

    On the evening of June 15, 2008, ALICE physicists saw the first tracks at LHC during the first injection test in transfer line TI 2. The Silicon Pixel detector recorded muon tracks produced in the beam dump near Point 2 of the LHC

  18. Edgeless silicon sensors for Medipix-based large-area X-ray imaging detectors

    International Nuclear Information System (INIS)

    Some X-ray imaging applications demand sensitive areas exceeding the active area of a single sensor. This requires a seamless tessellation of multiple detector modules with edgeless sensors. Our research is aimed at minimising the insensitive periphery that isolates the active area from the edge. Reduction of the edge-defect induced charge injection, caused by the deleterious effects of dicing, is an important step. We report on the electrical characterisation of 300 μm thick edgeless silicon p+-ν-n+ diodes, diced using deep reactive ion etching. Sensors with both n-type and p-type stop rings were fabricated in various edge topologies. Leakage currents in the active area are compared with those of sensors with a conventional design. As expected, we observe an inverse correlation between leakage-current density and both the edge distance and stop-ring width. From this correlation we determine a minimum acceptable edge distance of 50 μm. We also conclude that structures with a p-type stop ring show lower leakage currents and higher breakdown voltages than the ones with an n-type stop ring.

  19. Development of large area silicon semiconductor detectors for use in the current mode

    International Nuclear Information System (INIS)

    Large area silicon semiconductor detectors for use in the current mode, with their dimensions of φ40, φ50 and φ60 mm, their depletion thickness of 200-300 μm, have been developed. Their performance measurements have been made, which indicate that the developed detectors can satisfactorily meet the needs in expectation. Compared with the detectors commercially available on the market, authors' large PIN detectors can serve both as reliable and efficient high-resolution devices for nuclear counting experiments, as well as monitors of high-intensity radiation fields in the current mode under a bias of 100-1000 V, while the detectors commercially available are only for the counting use

  20. Controllable chemical vapor deposition of large area uniform nanocrystalline graphene directly on silicon dioxide

    DEFF Research Database (Denmark)

    Sun, Jie; Lindvall, Niclas; Cole, Matthew T.;

    2012-01-01

    graphene) and up to 13% of electric-field effect. The Hall mobility is similar to 40 cm(2)/ Vs, which is an order of magnitude higher than previously reported values for nanocrystalline graphene. Transmission electron microscopy, Raman spectroscopy, and transport measurements indicate a graphene......Metal-catalyst-free chemical vapor deposition (CVD) of large area uniform nanocrystalline graphene on oxidized silicon substrates is demonstrated. The material grows slowly, allowing for thickness control down to monolayer graphene. The as-grown thin films are continuous with no observable pinholes......, and are smooth and uniform across whole wafers, as inspected by optical-, scanning electron-, and atomic force microscopy. The sp(2) hybridized carbon structure is confirmed by Raman spectroscopy. Room temperature electrical measurements show ohmic behavior (sheet resistance similar to exfoliated...

  1. Strain dyssynchrony index determined by three-dimensional speckle area tracking can predict response to cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Onishi Tetsuari

    2011-04-01

    Full Text Available Abstract Background We have previously reported strain dyssynchrony index assessed by two-dimensional speckle tracking strain, and a marker of both dyssynchrony and residual myocardial contractility, can predict response to cardiac resynchronization therapy (CRT. A newly developed three-dimensional (3-D speckle tracking system can quantify endocardial area change ratio (area strain, which coupled with the factors of both longitudinal and circumferential strain, from all 16 standard left ventricular (LV segments using complete 3-D pyramidal datasets. Our objective was to test the hypothesis that strain dyssynchrony index using area tracking (ASDI can quantify dyssynchrony and predict response to CRT. Methods We studied 14 heart failure patients with ejection fraction of 27 ± 7% (all≤35% and QRS duration of 172 ± 30 ms (all≥120 ms who underwent CRT. Echocardiography was performed before and 6-month after CRT. ASDI was calculated as the average difference between peak and end-systolic area strain of LV endocardium obtained from 3-D speckle tracking imaging using 16 segments. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, Yu Index, and two-dimensional radial dyssynchrony by speckle-tracking strain. Response was defined as a ≥15% decrease in LV end-systolic volume 6-month after CRT. Results ASDI ≥ 3.8% was the best predictor of response to CRT with a sensitivity of 78%, specificity of 100% and area under the curve (AUC of 0.93 (p Conclusions ASDI can predict responders and LV reverse remodeling following CRT. This novel index using the 3-D speckle tracking system, which shows circumferential and longitudinal LV dyssynchrony and residual endocardial contractility, may thus have clinical significance for CRT patients.

  2. The STAR Tracking Upgrade

    CERN Document Server

    Simon, Frank

    2007-01-01

    The STAR experiment at the Relativistic Heavy Ion Collider RHIC studies the new state of matter produced in relativistic heavy ion collisions and the spin structure of the nucleon in collisions of polarized protons. In order to improve the capabilities for heavy flavor measurements and the reconstruction of charged vector bosons an upgrade of the tracking system both in the central and the forward region is pursued. The challenging environments of high track multiplicity in heavy ion collisions and of high luminosity in polarized proton collisions require the use of new technologies. The proposed inner tracking system, optimized for heavy flavor identification, is using active pixel sensors close to the collision point and silicon strip technology further outward. Charge sign determination for electrons and positrons from the decay of W bosons will be provide by 6 large-area triple GEM disks currently under development. A prototype of the active pixel detectors has been tested in the STAR experiment, and an e...

  3. A large-area monolithic array of silicon drift detectors for medical imaging

    International Nuclear Information System (INIS)

    Monolithic arrays of silicon drift detectors (SDDs) have been recently proposed to be used with scintillators for high-position-resolution γ-ray imaging applications. Thanks to the low electronics noise due to the small value of the output capacitance, the SDD offers better noise performances with respect to conventional photodiodes of the same geometry. Small monolithic arrays of SDDs have been used as photodetector of the scintillation light in a first prototype of Anger Camera for γ-ray imaging characterized by an intrinsic resolution better than 0.3 mm. In this work, we present a new large-area monolithic array of SDDs. It consists of a single chip composed of 77 single hexagonal units, each one with an active area of 8.7 mm2, for a total active area of the device of 6.7 cm2. It represents the largest monolithic array of SDDs with on-chip JFETs produced up to now for X-ray and γ-ray detection. The results achieved in the experimental characterization of a first prototype of the detector array are presented, both with X and visible photons. The energy resolution measured at 6 keV with the single unit of the array is of 142 eV at -10 oC, while a QE>90% was measured at λ=550 nm

  4. Simulation-Based Optimization of Cure Cycle of Large Area Compression Molding for LED Silicone Lens

    Directory of Open Access Journals (Sweden)

    Min-Jae Song

    2015-01-01

    Full Text Available Three-dimensional heat transfer-curing simulation was performed for the curing process by introducing a large area compression molding for simultaneous forming and mass production for the lens and encapsulants in the LED molding process. A dynamic cure kinetics model for the silicone resin was adopted and cure model and analysis result were validated and compared through a temperature measurement experiment for cylinder geometry with cure model. The temperature deviation between each lens cavity could be reduced by implementing a simulation model on the large area compression mold and by optimizing the location of heat source. A two-step cure cycle was constructed to reduce excessive reaction peak at the initial stage and cycle time. An optimum cure cycle that could reduce cycle time by more than 29% compared to a one-step cure cycle by adjusting dwell temperature, heating rate, and dwell time was proposed. It was thus confirmed that an optimization of large area LED lens molding process was possible by using the present experiment and the finite element method.

  5. Development of an area monitor for neutrons using solid state nuclear track detector

    International Nuclear Information System (INIS)

    An area monitor for neutrons composed of the solid state nuclear track detector (SSNTD) Makrofol DE, together with a (n,α) converter, in the center of a 25 cm diameter polyethylene sphere, is developed. The optimal electrochemical etching conditions for the detection of thermal neutrons by the Makrofol DE using the BN converter are studied, leading to the choice of 55 min, at 300 C, under a 44,2 kV.cm-1 electric field with oscillation frequency of 2,0 khz. The response of this system to thermal neutrons, in the optimal conditions, is of 2,76(10)x 10-3 tr/n. Changing from the BN converter to a 2,73(3)g compressed boric acid tablet this value lowers to 3,88(17)x 10-4 tr/n. The performance of the whole monitor in the detection of fast neutrons is examined using the BN converter and neutrons from a 241 Am Be source, with a response of 4,4(2)x 103 tr.mSv-1.cm-2 and operational limits between 7(3)μSv and 5,6(2)mSv. The result of the monitoring of the control room of the IPEN Cyclotron accelerator are also presented as a final test for the viability of the practical use of the monitor. (author). 34 refs, 15 figs, 6 tabs, 1 app

  6. Coherent Bremsstrahlung effect observed during STEM analysis of dopant distribution in silicon devices using large area silicon drift EDX detectors and high brightness electron source

    International Nuclear Information System (INIS)

    In this paper, during dopant analysis of silicon devices, we have observed a phenomenon generally neglected in EDX analysis: the coherent Bremsstrahlung (CB). We discussed the reason why and came to the conclusion that the analytical TEM used for these experiments presents a configuration and performances, which makes this equipment very sensitive to the CB effect. This is due to large collection solid angle and high counting rate of the four silicon drift EDX detectors (SDD), a high brightness electron source providing large probe current and moreover a geometry favorable to on axis crystal observations. We analyzed silicon devices containing Si [110] and Si [100] crystal areas at different energies (80–120–200 keV). We also observed relaxed SiGe (27 and 40 at% of Ge). The CB effect, whose intensity is maximum near zone axis beam alignment, manifests as characteristic broad peaks present in the X-ray spectrum background. The peak energies are predicted by a simple formula deduced for the CB models found in the literature and that we present simply. We evaluate also the CB peak intensities and discuss the importance of this effect on the detection and quantification traces of impurities. The CB peaks also give information on the analyzed crystal structure (measurement of the periodicity along the zone axis) and allow, in every particular experiment or system, to determine the median take off angle of the EDX detectors. -- Highlights: ► STEM EDX dopant distribution analysis (As and P) in Si devices is carried out. ► High brightness electron source and four EDX Silicon Drift detectors are used. ► The obtained signal dynamics (four decades) allows detection down to 0.01 at%. ► During silicon axis analysis coherent Bremmsstrahlung is observed. ► This effect is studied at different energies and Si crystal orientations.

  7. Nanopillars: Large Area Fabrication of Leaning Silicon Nanopillars for Surface Enhanced Raman Spectroscopy (Adv. Mater. 10/2012)

    DEFF Research Database (Denmark)

    Schmidt, Michael Stenbæk; Hübner, Jörg; Boisen, Anja

    2012-01-01

    M. S. Schmidt et al. describe on page OP11 a simple, two-step fabrication process to as-semble flexible, freestanding nanopillars into large-area substrates. These substrates can be made using readily available silicon-processing equipment and are suitable for SERS, having a large, uniform Raman...

  8. Surface States and Effective Surface Area on Photoluminescent P-Type Porous Silicon

    Science.gov (United States)

    Weisz, S. Z.; Porras, A. Ramirez; Resto, O.; Goldstein, Y.; Many, A.; Savir, E.

    1997-01-01

    The present study is motivated by the possibility of utilizing porous silicon for spectral sensors. Pulse measurements on the porous-Si/electrolyte system are employed to determine the surface effective area and the surface-state density at various stages of the anodization process used to produce the porous material. Such measurements were combined with studies of the photoluminescence spectra. These spectra were found to shift progressively to the blue as a function of anodization time. The luminescence intensity increases initially with anodization time, reaches a maximum and then decreases with further anodization. The surface state density, on the other hand, increases with anodization time from an initial value of about 2 x 10(exp 12)/sq cm surface to about 1013 sq cm for the anodized surface. This value is attained already after -2 min anodization and upon further anodization remains fairly constant. In parallel, the effective surface area increases by a factor of 10-30. This behavior is markedly different from the one observed previously for n-type porous Si.

  9. Large-Area, UV-Optimized, Back-Illuminated Silicon Photomultiplier Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Existing photocathode-based technologies for visible and UV instruments lack sensitivity, are bulky, and have limited reliability. Solid-state silicon...

  10. Development of a Thick-film Silicon Ribbon Growth Technique for Application to Large-area Solar Cells and Arrays

    Science.gov (United States)

    Berman, P. A.

    1973-01-01

    A new technique is described for growth of large-area silicon ribbons. This technique is an edge-defined, film-fed growth process by which single crystals can be grown having a shape controlled by the outside dimensions of a shaping die, growth taking place from an extremely thin film of liquid fed by capillary action from a crucible below. The material from which the die is fabricated is very critical to the process. The die must be wet by the silicon, but adverse impurities must not be introduced into the silicon, and the die must not become degraded by the molten silicon. A breakthrough in die fabrication that has allowed the growth of silicon ribbons having dimensions of 1 cm by 30 cm with a thickness of 0.7 mm is described. The implications of this significant advancement with respect to development of photovoltaic solar arrays for wide-scale terrestrial solar-to-electric energy conversion systems are discussed.

  11. Coherent Bremsstrahlung effect observed during STEM analysis of dopant distribution in silicon devices using large area silicon drift EDX detectors and high brightness electron source.

    Science.gov (United States)

    Pantel, R

    2011-11-01

    In this paper, during dopant analysis of silicon devices, we have observed a phenomenon generally neglected in EDX analysis: the coherent Bremsstrahlung (CB). We discussed the reason why and came to the conclusion that the analytical TEM used for these experiments presents a configuration and performances, which makes this equipment very sensitive to the CB effect. This is due to large collection solid angle and high counting rate of the four silicon drift EDX detectors (SDD), a high brightness electron source providing large probe current and moreover a geometry favorable to on axis crystal observations. We analyzed silicon devices containing Si [110] and Si [100] crystal areas at different energies (80-120-200keV). We also observed relaxed SiGe (27 and 40at% of Ge). The CB effect, whose intensity is maximum near zone axis beam alignment, manifests as characteristic broad peaks present in the X-ray spectrum background. The peak energies are predicted by a simple formula deduced for the CB models found in the literature and that we present simply. We evaluate also the CB peak intensities and discuss the importance of this effect on the detection and quantification traces of impurities. The CB peaks also give information on the analyzed crystal structure (measurement of the periodicity along the zone axis) and allow, in every particular experiment or system, to determine the median take off angle of the EDX detectors. PMID:21946001

  12. Irradiation of large area Mylar membrane and characterization of nuclear track filter

    Indian Academy of Sciences (India)

    N K Acharya; P K Yadav; S Wate; Y K Vijay; F Singh; D K Avasthi

    2004-10-01

    Ion irradiation of Si8+ ion beam of 100 MeV was scattered by a gold foil on a Mylar membrane of 25 m thickness in the form of film roll (width, 12.5 cm and length, 400 cm) at the Nuclear Science Centre, New Delhi. The characterization of etched nuclear tracks was carried out by gas permeation measurements. The samples cut from the film roll of required size for permeability measurements were etched in a controlled manner in a constant temperature bath of 6N NaOH solution. The opening of the conical etched tracks was characterized by hydrogen gas permeation.

  13. Foreshowing of the Western Pacific tropical cyclone track to PM10 air pollution episode in the Beijing area

    Institute of Scientific and Technical Information of China (English)

    WANG XiQuan; WANG ZiFa; YU Tong; GONG YanBang

    2009-01-01

    By utilizing the air quality monitoring data and the NCEP reanalysis data, the relationship between the PM10 air pollution episode and synoptic situation is analyzed in the Beijing area. It is interesting to find that PM10 air pollution episode in and around the Beijing area is correlated with the Western Pacific tropical cyclone track to some extent, namely when a tropical cyclone lands southward to the Chang-jiang River, PM10 air pollution episode is not easy to take place generally in the Beijing area; but when a tropical cyclone moves northward and finally lands at the Korea Peninsula or the Japanese mainland, and under this condition the Beijing area is generally controlled by weak high or weak low for several days, PM10 air pollution episode often takes place in one day or several days. Above findings indicate that predicting the Western Pacific tropical cyclone track can foretell whether or not PM10 air pollution episode takes place in the Beijing area, which can offer a technique for urban air quality prediction and air pollution source management in the Beijing area.

  14. ALICE silicon strip module

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    This small silicon detector strip will be inserted into the inner tracking system (ITS) on the ALICE detector at CERN. This detector relies on state-of-the-art particle tracking techniques. These double-sided silicon strip modules have been designed to be as lightweight and delicate as possible as the ITS will eventually contain five square metres of these devices.

  15. Tracking Efficiency and Charge Sharing of 3D Silicon Sensors at Different Angles in a 1.4T Magnetic Field

    International Nuclear Information System (INIS)

    A 3D silicon sensor fabricated at Stanford with electrodes penetrating throughout the entire silicon wafer and with active edges was tested in a 1.4 T magnetic field with a 180 GeV/c pion beam at the CERN SPS in May 2009. The device under test was bump-bonded to the ATLAS pixel FE-I3 readout electronics chip. Three readout electrodes were used to cover the 400 (micro)m long pixel side, this resulting in a p-n inter-electrode distance of ∼ 71 (micro)m. Its behavior was confronted with a planar sensor of the type presently installed in the ATLAS inner tracker. Time over threshold, charge sharing and tracking efficiency data were collected at zero and 15o angles with and without magnetic field. The latest is the angular configuration expected for the modules of the Insertable B-Layer (IBL) currently under study for the LHC phase 1 upgrade expected in 2014.

  16. Large-area Silicon-Film{trademark} panels and solar cells. Phase 2 technical report, January 1996--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Rand, J.A.; Barnett, A.M.; Checchi, J.C.; Culik, J.S.; Collins, S.R.; Ford, D.H.; Hall, R.B.; Jackson, E.L.; Kendall, C.L. [AstroPower Inc., Newark, DE (United States)

    1997-03-01

    The Silicon-Film{trademark} process is on an accelerated path to large-scale manufacturing. A key element in that development is optimizing the specific geometry of both the Silicon-Film{trademark} sheet and the resulting solar cell. That decision has been influenced by cost factors, engineering concerns, and marketing issues. The geometry investigation has focused first on sheet nominally 15 cm wide. This sheet generated solar cells with areas of 240 cm{sup 2} and 675 cm{sup 2}. Most recently, a new sheet fabrication machine was constructed that produces Silicon-Film{trademark} with a width in excess of 30 cm. Test results have indicated that there is no limit to the width of sheet generated by this process. The new wide material has led to prototype solar cells with areas of 300, 400, and 1,800 cm{sup 2}. Significant advances in solar-cell processing have been developed in support of fabricating large-area devices, including uniform emitter diffusion and anti-reflection coatings.

  17. Initial steps toward the realization of large area arrays of single photon counting pixels based on polycrystalline silicon TFTs

    Science.gov (United States)

    Liang, Albert K.; Koniczek, Martin; Antonuk, Larry E.; El-Mohri, Youcef; Zhao, Qihua; Jiang, Hao; Street, Robert A.; Lu, Jeng Ping

    2014-03-01

    The thin-film semiconductor processing methods that enabled creation of inexpensive liquid crystal displays based on amorphous silicon transistors for cell phones and televisions, as well as desktop, laptop and mobile computers, also facilitated the development of devices that have become ubiquitous in medical x-ray imaging environments. These devices, called active matrix flat-panel imagers (AMFPIs), measure the integrated signal generated by incident X rays and offer detection areas as large as ~43×43 cm2. In recent years, there has been growing interest in medical x-ray imagers that record information from X ray photons on an individual basis. However, such photon counting devices have generally been based on crystalline silicon, a material not inherently suited to the cost-effective manufacture of monolithic devices of a size comparable to that of AMFPIs. Motivated by these considerations, we have developed an initial set of small area prototype arrays using thin-film processing methods and polycrystalline silicon transistors. These prototypes were developed in the spirit of exploring the possibility of creating large area arrays offering single photon counting capabilities and, to our knowledge, are the first photon counting arrays fabricated using thin film techniques. In this paper, the architecture of the prototype pixels is presented and considerations that influenced the design of the pixel circuits, including amplifier noise, TFT performance variations, and minimum feature size, are discussed.

  18. Magnetically enhanced triode etching of large area silicon membranes in a molecular bromine plasma

    International Nuclear Information System (INIS)

    The optimization of a process for etching 125 mm silicon membranes formed on 150 mm wafers and bonded to Pyrex rings is discussed. A magnetically enhanced triode etching system was designed to provide an intense, remote plasma surrounding the membrane while, at the same time, suppressing the discharge over the membrane itself. For the optimized molecular bromine process, the silicon etch rate is 40 nm/min and the selectivity relative to SiO2 is 160:1. 14 refs., 6 figs

  19. Selected area laser-crystallized polycrystalline silicon thin films by a pulsed Nd:YAG laser with 355 nm wavelength

    Institute of Scientific and Technical Information of China (English)

    Duan Chunyan; Liu Chao; Ai Bin; Lai Jianjun; Deng Youjun; Shen Hui

    2011-01-01

    Selected area laser-crystallized polycrystalline silicon(p-Si)thin films were prepared by the third harmonics(355 nm wavelength)generated by a solid-state pulsed Nd:YAG laser.Surface morphologies of 400 nm thick films after laser irradiation were analyzed.Raman spectra show that film crystallinity is improved with increase of laser energy.The optimum laser energy density is sensitive to the film thickness.The laser energy density for efficiently crystallizing amorphous silicon films is between 440-634 mJ/cm2 for 300 nm thick films and between 777-993 mJ/cm2 for 400 nm thick films.The optimized laser energy density is 634,975 and 1571 mJ/cm2 for 300,400 and 500 nm thick films,respectively.

  20. Process Simulation and Characterization of Substrate Engineered Silicon Thin Film Transistor for Display Sensors and Large Area Electronics

    International Nuclear Information System (INIS)

    Design, simulation, fabrication and post-process qualification of substrate-engineered Thin Film Transistors (TFTs) are carried out to suggest an alternate manufacturing process step focused on display sensors and large area electronics applications. Damage created by ion implantation of Helium and Silicon ions into single-crystalline n-type silicon substrate provides an alternate route to create an amorphized region responsible for the fabrication of TFT structures with controllable and application-specific output parameters. The post-process qualification of starting material and full-cycle devices using Rutherford Backscattering Spectrometry (RBS) and Proton or Particle induced X-ray Emission (PIXE) techniques also provide an insight to optimize the process protocols as well as their applicability in the manufacturing cycle

  1. Assessment of fast and thermal neutron ambient dose equivalents around the KFUPM neutron source storage area using nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abu-Jarad, F. [Radiation Protection Unit, Environmental Protection Department, Saudi Aramco, P. O. Box 13027, Dhahran 31311 (Saudi Arabia); Qureshi, M.A. [Center for Applied Physical Sciences, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-11-15

    A set of five {sup 241}Am-Be neutron sources are utilized in research and teaching at King Fahd University of Petroleum and Minerals (KFUPM). Three of these sources have an activity of 16Ci each and the other two are of 5Ci each. A well-shielded storage area was designed for these sources. The aim of the study is to check the effectiveness of shielding of the KFUPM neutron source storage area. Poly allyl diglycol carbonate (PADC) Nuclear track detectors (NTDs) based fast and thermal neutron area passive dosimeters have been utilized side by side for 33 days to assess accumulated low ambient dose equivalents of fast and thermal neutrons at 30 different locations around the source storage area and adjacent rooms. Fast neutron measurements have been carried out using bare NTDs, which register fast neutrons through recoils of protons, in the detector material. NTDs were mounted with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters on their surfaces for thermal neutron detection via B10(n,{alpha})Li6 and Li6(n,{alpha})H3 nuclear reactions. The calibration factors of NTD both for fast and thermal neutron area passive dosimeters were determined using thermoluminescent dosimeters (TLD) with and without a polyethylene moderator. The calibration factors for fast and thermal neutron area passive dosimeters were found to be 1.33 proton tracks cm{sup -2}{mu}Sv{sup -1} and 31.5 alpha tracks cm{sup -2}{mu}Sv{sup -1}, respectively. The results show variations of accumulated dose with the locations around the storage area. The fast neutron dose equivalents rates varied from as low as 182nSvh{sup -1} up to 10.4{mu}Svh{sup -1} whereas those for thermal neutron ranged from as low as 7nSvh{sup -1} up to 9.3{mu}Svh{sup -1}. The study indicates that the area passive neutron dosimeter was able to detect dose rates as low as 7 and 182nSvh{sup -1} from accumulated dose for thermal and fast neutrons, respectively, which were not possible to detect with the available active neutron

  2. Measurement of radon concentration in dwellings belonging to some areas of Pathankot district, Punjab using solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Indoor radon studies have been carried out in the environs of some areas of Pathankot district, Punjab, India using LR-115 type II plastic track detector. The area lies in the vicinity of Himachal Himalayas known for uranium mineralization. The work has been undertaken for the health risk assessments. The indoor radon concentration in 10 different villages of the area is found to vary from 163.91 Bqm-3 to 437.21 Bqm-3. The average radon concentration in dwellings in most of the villages falls in the action level (200-600 Bqm-3) recommended by International Commission on Radiological Protection (ICRP). The values are also found to be higher in poorly ventilated houses compared with the well ventilated houses. (author)

  3. Large-eddy simulation of ship tracks in the collapsed marine boundary layer: a case study from the Monterey Area Ship Track experiment

    Directory of Open Access Journals (Sweden)

    A. H. Berner

    2014-09-01

    Full Text Available For the first time, a large-eddy simulation (LES coupled to a bulk aerosol scheme is used to simulate an aircraft-sampled ship track. The track was formed by the M/V Sanko Peace on 13 June 1994 in a shallow drizzling boundary layer with high winds but very low background aerosol concentrations (10 cm−3. A Lagrangian framework is used to simulate the evolution of a short segment of track as it is advected away from the ship for eight hours (a downwind distance exceeding 570 km. Using aircraft observations for initialization, good agreement is obtained between the simulated and observed features of the ambient boundary layer outside the track, including the organization of cloud into mesoscale rolls. After eight hours, a line of aerosol is injected to start the ship track. The simulation successfully reproduces the significant albedo enhancement and suppression of drizzle observed within the track. The aerosol concentration within the track dilutes as it broadens due to turbulent mixing. A sensitivity study shows the broadening rate strongly depends on the alignment between the track and the wind-aligned boundary layer rolls, as satellite images of ship tracks suggest. Entrainment is enhanced within the simulated track, but the observed 100 m elevation of the ship track above the surrounding layer is not simulated, possibly because the LES quickly sharpens the rather weak observed inversion. Liquid water path within the simulated track increases with time even as the ambient liquid water path is decreasing. The albedo increase in the track from liquid water and cloud fraction enhancement (second indirect effect eventually exceeds that from cloud droplet number increases (first indirect or Twomey effect. In a sensitivity study with a higher initial ambient aerosol concentration, stronger ship track aerosol source, and much weaker drizzle, there is less liquid water inside the track than outside for several hours downwind, consistent with

  4. Light management in large area thin-film silicon solar modules

    Czech Academy of Sciences Publication Activity Database

    Losio, P.A.; Caglar, O.; Cashmore, J.S.; Hötzel, J.E.; Ristau, S.; Holovský, Jakub; Remeš, Zdeněk; Sinicco, I.

    2015-01-01

    Roč. 143, Dec (2015), s. 375-385. ISSN 0927-0248 R&D Projects: GA ČR(CZ) GA14-05053S Institutional support: RVO:68378271 Keywords : micromorph * thin- film silicon solar cells * light management * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.337, year: 2014

  5. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 539: Area 25 and Area 26 Railroad Tracks, Nevada Test Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2010-06-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 539, Areas 25 and 26 Railroad Tracks, as identified in the Federal Facility Agreement and Consent Order (FFACO). A modification to the FFACOwas approved in May 2010 to transfer the two Railroad Tracks corrective action sites (CASs) from CAU 114 into CAU539. The two CASs are located in Areas 25 and 26 of the Nevada Test Site: • 25-99-21, Area 25 Railroad Tracks • 26-99-05, Area 26 Railroad Tracks This plan provides the methodology for field activities needed to gather the necessary information for closing the two CASs. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of the CAU 539 Railroad Tracks CASs using the SAFER process. Additional information will be obtained by conducting a field investigation before selecting the appropriate corrective action for each CAS. The results of the field investigation should support a defensible recommendation that no further corrective action is necessary. If it is determined that complete clean closure cannot be accomplished during the SAFER, then a hold point will have been reached and the Nevada Division of Environmental Protection (NDEP) will be consulted to determine whether the remaining contamination will be closed under the alternative corrective action of closure in place with use restrictions. This will be presented in a closure report that will be prepared and submitted to the NDEP for review and approval. The sites will be investigated based on the data quality objectives (DQOs) developed on December 14, 2009, by representatives of U.S.Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office; Navarro Nevada Environmental Services, LLC (NNES); and National Security Technologies

  6. FAST TRACK COMMUNICATION: Enhanced dc conductivity of low volume-fraction nano-particulate suspensions in silicone and perfluorinated oils

    Science.gov (United States)

    Wilson, S. A.; Libor, Z.; Skordos, A. A.; Zhang, Q.

    2009-03-01

    The dc conductivities of several different types of nanoparticles (nickel, barium titanate and magnetite) suspended in both silicone and perfluorinated oils have been measured and contrasted. Enhanced dc conductivity through interaction between the particles and the fluid has been demonstrated, even at quite moderate fields, and different types of nanoparticles have been shown to exhibit different behavioural trends. Whilst the dc enhancement is partly related to the concentration (or spatial arrangement) of the particles as expected, there is clear evidence that energy-activated (electric field activated) processes also play a major role. It can be said that effective-medium theories based solely on the electrical properties and volume fractions of the component materials have limited applicability when assessing the dc conductivities of these nanoparticle-fluid combinations at low volume fractions.

  7. Investigating the Potential of Activity Tracking App Data to Estimate Cycle Flows in Urban Areas

    Science.gov (United States)

    Haworth, J.

    2016-06-01

    Traffic congestion and its associated environmental effects pose a significant problem for large cities. Consequently, promoting and investing in green travel modes such as cycling is high on the agenda for many transport authorities. In order to target investment in cycling infrastructure and improve the experience of cyclists on the road, it is important to know where they are. Unfortunately, investment in intelligent transportation systems over the years has mainly focussed on monitoring vehicular traffic, and comparatively little is known about where cyclists are on a day to day basis. In London, for example, there are a limited number of automatic cycle counters installed on the network, which provide only part of the picture. These are supplemented by surveys that are carried out infrequently. Activity tracking apps on smart phones and GPS devices such as Strava have become very popular over recent years. Their intended use is to track physical activity and monitor training. However, many people routinely use such apps to record their daily commutes by bicycle. At the aggregate level, these data provide a potentially rich source of information about the movement and behaviour of cyclists. Before such data can be relied upon, however, it is necessary to examine their representativeness and understand their potential biases. In this study, the flows obtained from Strava Metro (SM) are compared with those obtained during the 2013 London Cycle Census (LCC). A set of linear regression models are constructed to predict LCC flows using SM flows along with a number of dummy variables including road type, hour of day, day of week and presence/absence of cycle lane. Cross-validation is used to test the fitted models on unseen LCC sites. SM flows are found to be a statistically significant (p<0.0001) predictor of total flows as measured by the LCC and the models yield R squared statistics of ~0.7 before considering spatio-temporal variation. The initial results indicate

  8. Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps

    Science.gov (United States)

    Closset, Ivia; Cardinal, Damien; Bray, Stephen G.; Thil, François; Djouraev, Irina; Rigual-Hernández, Andrés. S.; Trull, Thomas W.

    2015-09-01

    The Southern Ocean plays a pivotal role in the control of atmospheric CO2 levels, via both physical and biological sequestration processes. The biological carbon transfer to the ocean interior is tightly coupled to the availability of other elements, especially iron as a trace-limiting nutrient and dissolved silicon as the mineral substrate that allows diatoms to dominate primary production. Importantly, variations in the silicon cycling are large but not well understood. Here we use δ30Si measurements to track seasonal flows of silica to the deep sea, as captured by sediment trap time series, for the three major zones (Antarctic, AZ; Polar Frontal, PFZ; and Sub-Antarctic, SAZ) of the open Southern Ocean. Variations in the exported flux of biogenic silica (BSi) and its δ30Si composition reveal a range of insights, including that (i) the sinking rate of BSi exceeds 200 m d-1 in summer in the AZ yet decreases to very low values in winter that allow particles to remain in the water column through to the following spring, (ii) occasional vertical mixing events affect the δ30Si composition of exported BSi in both the SAZ and AZ, and (iii) the δ30Si signature of diatoms is well conserved through the water column despite strong BSi and particulate organic carbon (POC) attenuation at depth and is closely linked to the Si consumption in surface waters. With the strong coupling observed between BSi and POC fluxes in PFZ and AZ, these data provide new constraints for application to biogeochemical models of seasonal controls on production and export.

  9. Behaviour of interatomic interaction potentials in metal in the track area of heavy charged particles

    International Nuclear Information System (INIS)

    The computational technique of interatomic interaction potentials in the presence of ionized states is developed. Using aluminium as an example, they are obtained for atoms with different ionization degree. The molecular-dynamic modeling of atom transfer in crystal lattice has shown that ion emission from fast charged particle track near surface (coulomb explosion) is possible if the life time of ionized states is 10-13 s or more. On the base of pseudopotential approach behaviour of interaction potentials in conditions of electron subsystem excitation is analyzed. It has been found out that thermal tailing of Fermi surface does not result in essential change of interatomic interaction forces, and the local increase of conduction electrons concentration induces softening of crystal lattice when configuration with lesser interatomic distance becomes equilibrium

  10. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  11. Improvements in data analysis obtained by large-area silicon ΔE - E detector telescopes

    International Nuclear Information System (INIS)

    The paper describes a few practical methods for the analysis of data obtained by standard thin-thick silicon detector telescopes used in nuclear reaction measurements. The addressed issues are: (1) improvement in double-sided silicon strip detector (DSSSD) calibration based on the fact that each event is registered twice, both in horizontal and vertical strips, (2) improvements in particle identification and (3) simplified mapping of the non-uniformity of the thin detector, without a dedicated measurement of the thickness. The proposed procedures are applied on experimental data obtained for 30MeV 7Li beam induced reactions on LiF and C targets, studied with a detection setup consisting of four telescopes placed at different angles and distances. The proposed methods aim at quicker and more reliable calibration and particle identification. (orig.)

  12. Improvements in data analysis obtained by large-area silicon ΔE - E detector telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Uroic, M.; Miljanic, D.; Prepolec, L.; Soic, N. [Ruder Boskovic Institute, Zagreb (Croatia); Milin, M. [University of Zagreb, Department of Physics, Faculty of Science, Zagreb (Croatia); Di Pietro, A.; Figuera, P.; Fisichella, M.; Pellegriti, M.G.; Scuderi, V. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Lattuada, M. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Universtita' di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Martel, I. [Universidad de Huelva, Departamento de Fisica Aplicada, Huelva (Spain); Sanchez Benitez, A.M. [Universidad de Huelva, Departamento de Fisica Aplicada, Huelva (Spain); Universidade de Lisboa, Centro de Fisica Nuclear da, Lisboa (Portugal); Strano, E.; Torresi, D. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Laboratori Nazionali di Legnaro, INFN, Legnaro (Italy)

    2015-08-15

    The paper describes a few practical methods for the analysis of data obtained by standard thin-thick silicon detector telescopes used in nuclear reaction measurements. The addressed issues are: (1) improvement in double-sided silicon strip detector (DSSSD) calibration based on the fact that each event is registered twice, both in horizontal and vertical strips, (2) improvements in particle identification and (3) simplified mapping of the non-uniformity of the thin detector, without a dedicated measurement of the thickness. The proposed procedures are applied on experimental data obtained for 30MeV {sup 7}Li beam induced reactions on LiF and C targets, studied with a detection setup consisting of four telescopes placed at different angles and distances. The proposed methods aim at quicker and more reliable calibration and particle identification. (orig.)

  13. High-rate deposition of microcrystalline silicon in a large-area PECVD reactor and integration in tandem solar cells

    OpenAIRE

    Parascandolo, G; Bugnon, G.; Feltrin, A.; Ballif, C.

    2010-01-01

    We study the high-rate deposition of microcrystalline silicon in a large-area plasma-enhanced chemical-vapor-deposition (PECVD) reactor operated at 40.68 MHz, in the little-explored process conditions of high-pressure and high-silane concentration and depletion. Due to the long gas residence time in this process, the silane gas is efficiently depleted using moderate feed-in power density, thus facilitating up-scaling of the process to large surfaces. As observed in more traditional deposition...

  14. Influence of stain etching on low minority carrier lifetime areas of multicrystalline silicon for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Montesdeoca-Santana, A. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Fraunhofer Institute for Solar Energy Systems, Laboratory and Servicecenter Gelsenkirchen, Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Gonzalez-Diaz, B. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Departamento de Energia Fotovoltaica, Instituto Tecnologico y de Energias Renovables. Poligono Industrial de Granadilla s/n, 38600 San Isidro-Granadilla de Abona (Spain); Jimenez-Rodriguez, E. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Ziegler, J. [Fraunhofer Institute for Solar Energy Systems, Laboratory- and Servicecenter Gelsenkirchen. Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Velazquez, J.J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna. Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Hohage, S.; Borchert, D. [Fraunhofer Institute for Solar Energy Systems, Laboratory and Servicecenter Gelsenkirchen. Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Guerrero-Lemus, R., E-mail: rglemus@ull.es [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain)

    2011-11-15

    Highlights: > An enhanced minority carrier lifetime at extended defects in multicrystalline silicon is observed with the use of HF/HNO{sub 3} stain etching to texture the surface. > FTIR analysis shows no influence of oxide passivation in this effect. > SEM images show a preferential etching at extended defects suggesting smoothing at defects as one of the causes for the reduced recombination activity. > LBIC images show a reduction in IQE at extended defects in HF/HNO{sub 3} textured multicrystalline solar cells. - Abstract: In this work the use of HF/HNO{sub 3} solutions for texturing silicon-based solar cell substrates by stain etching and the influence of texturing on minority carrier lifetimes are studied. Stain etching is currently used to decrease the reflectance and, subsequently improve the photogenerated current of the cells, but also produces nanostructures on the silicon surface. In the textured samples it has been observed that an improvement on the minority carrier lifetime with respect to the samples treated with a conventional saw damage etching process is produced on grain boundaries and defects, and the origin of this effect has been discussed.

  15. Temperature-Dependent Photoluminescence Imaging and Characterization of a Multi-Crystalline Silicon Solar Cell Defect Area: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.; Yan, F.; Li, J.; Romero, M. J.; Al-Jassim, M.; Zaunbrecher, K.; Sidelkheir, O.; Blosse, A.

    2011-07-01

    Photoluminescence (PL) imaging is used to detect areas in multi-crystalline silicon that appear dark in band-to-band imaging due to high recombination. Steady-state PL intensity can be correlated to effective minority-carrier lifetime, and its temperature dependence can provide additional lifetime-limiting defect information. An area of high defect density has been laser cut from a multi-crystalline silicon solar cell. Both band-to-band and defect-band PL imaging have been collected as a function of temperature from ~85 to 350 K. Band-to-band luminescence is collected by an InGaAs camera using a 1200-nm short-pass filter, while defect band luminescence is collected using a 1350-nm long pass filter. The defect band luminescence is characterized by cathodo-luminescence. Small pieces from adjacent areas within the same wafer are measured by deep-level transient spectroscopy (DLTS). DLTS detects a minority-carrier electron trap level with an activation energy of 0.45 eV on the sample that contained defects as seen by imaging.

  16. Fabrication of Large-Area Hierarchical Structure Array Using Siliconized-Silsesquioxane as a Nanoscale Etching Barrier.

    Science.gov (United States)

    Lee, Bong Kuk; Baek, In-Bok; Kim, Yarkyeon; Jang, Won Ick; Yoon, Yong Sun; Yu, Han Young

    2015-06-24

    A material approach to fabricate a large-area hierarchical structure array is presented. The replica molding and oxygen (O2) plasma etching processes were combined to fabricate a large-area hierarchical structure array. Liquid blends consisting of siliconized silsesquioxane acrylate (Si-SSQA), ethylene glycol dimethacrylate (EGDMA), and photoinitiator are developed as a roughness amplifying material during O2 plasma etching. Microstructures composed of the Si-SSQA/EGDMA mixtures are fabricated by replica molding. Nanoscale roughness on molded microstructures is realized by O2 etching. The nanoscale roughness on microstructures is efficiently controlled by varying the etching time and the weight ratio of Si-SSQA to EGDMA. The hierarchical structures fabricated by combining replica molding and O2 plasma etching showed superhydrophilicity with long-term stability, resulting in the formation of hydroxyl-terminated silicon oxide layer with the reorientation limit. On the other hand, the hierarchical structures modified with a perfluorinated monolayer showed superhydrophobicity. The increment of water contact angles is consistent with increment of the nano/microroughness of hierarchical structures and decrement of the top contact area of water/hierarchical structures. PMID:26047057

  17. Groundwater Monitoring and Tritium-Tracking Plan for the 200 Area State-Approved Land Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    DB Barnett

    2000-08-31

    The 200 Area State-Approved Land Disposal Site (SALDS) is a drainfield which receives treated wastewater, occasionally containing tritium from treatment of Hanford Site liquid wastes at the 200 Area Effluent Treatment Facility (ETF). Since operation of the SALDS began in December 1995, discharges of tritium have totaled {approx}304 Ci, only half of what was originally predicted for tritium quantity through 1999. Total discharge volumes ({approx}2.7E+8 L) have been commensurate with predicted volumes to date. This document reports the results of all tritium analyses in groundwater as determined from the SALDS tritium-tracking network since the first SALDS wells were installed in 1992 through July 1999, and provides interpretation of these results as they relate to SALDS operation and its effect on groundwater. Hydrologic and geochemical information are synthesized to derive a conceptual model, which is in turn used to arrive at an appropriate approach to continued groundwater monitoring at the facility.

  18. Tracking Forest and Open Area Effects on Snow Accumulation by Unmanned Aerial Vehicle Photogrammetry

    Science.gov (United States)

    Lendzioch, T.; Langhammer, J.; Jenicek, M.

    2016-06-01

    Airborne digital photogrammetry is undergoing a renaissance. The availability of low-cost Unmanned Aerial Vehicle (UAV) platforms well adopted for digital photography and progress in software development now gives rise to apply this technique to different areas of research. Especially in determining snow depth spatial distributions, where repetitive mapping of cryosphere dynamics is crucial. Here, we introduce UAV-based digital photogrammetry as a rapid and robust approach for evaluating snow accumulation over small local areas (e.g., dead forest, open areas) and to reveal impacts related to changes in forest and snowpack. Due to the advancement of the technique, snow depth of selected study areas such as of healthy forest, disturbed forest, succession, dead forest, and of open areas can be estimated at a 1 cm spatial resolution. The approach is performed in two steps: 1) developing a high resolution Digital Elevation Model during snow-free and 2) during snow-covered conditions. By substracting these two models the snow depth can be accurately retrieved and volumetric changes of snow depth distribution can be achieved. This is a first proof-of-concept study combining snow depth determination and Leaf Area Index (LAI) retrieval to monitor the impact of forest canopy metrics on snow accumulation in coniferous forest within the Šumava National Park, Czech Republic. Both, downward-looking UAV images and upward-looking LAI-2200 canopy analyser measurements were applied to reveal the LAI, controlling interception and transmitting radiation. For the performance of downward-looking images the snow background instead of the sky fraction was used. In contrast to the classical determination of LAI by hemispherical photography or by LAI plant canopy analyser, our approach will also test the accuracy of LAI measurements by UAV that are taken simultaneously during the snow cover mapping campaigns. Since the LAI parameter is important for snowpack modelling, this method presents

  19. Seabird satellite tracking validates the use of latitudinal isoscapes to depict predators' foraging areas in the Southern Ocean.

    Science.gov (United States)

    Jaeger, Audrey; Lecomte, Vincent J; Weimerskirch, Henri; Richard, Pierre; Cherel, Yves

    2010-12-15

    Stable isotopes are increasingly being used to trace wildlife movements. A fundamental prerequisite of animal isotopic tracking is a good knowledge of spatial isotopic variations in the environment. Few accessible reference maps of the isotopic landscape ("isoscapes") are available for marine predators. Here, we validate for the first time an isotopic gradient for higher trophic levels by using a unique combination of a large number of satellite-tracks and subsequent blood plasma isotopic signatures from a wide-ranging oceanic predator. The plasma δ(13)C and δ(15)N values of wandering albatrosses (n = 45) were highly and positively correlated to the Southern Ocean latitudes at which the satellite-tracked individuals foraged. The well-defined latitudinal baseline carbon isoscapes in the Southern Ocean is thus reflected in the tissue of consumers, but with a positive shift due to the cumulative effect of a slight (13)C-enrichment at each trophic level. The data allowed us to estimate the carbon isotopic position of the main oceanic fronts in the area, and thus to delineate robust isoscapes of the main foraging zones for top predators. The plasma δ(13)C and δ(15)N values were positively and linearly correlated, thus suggesting that latitudinal isoscapes also occur for δ(15)N at the base of the food web in oceanic waters of the Southern Ocean. The combination of device deployments with sampling of relevant tissues for isotopic analysis appears to be a powerful tool for investigating consumers' isoscapes at various spatio-temporal scales. PMID:21072802

  20. Tracking influential haze source areas in North China using an adjoint model, GRAPES-CUACE

    Science.gov (United States)

    An, X. Q.; Zhai, S. X.; Jin, M.; Gong, S. L.; Wang, Y.

    2015-08-01

    Based upon the adjoint theory, the adjoint of the aerosol module in the atmospheric chemical modeling system GRAPES-CUACE (Global/Regional Assimilation and PrEdiction System coupled with the CMA Unified Atmospheric Chemistry Environment) was developed and tested for its correctness. Through statistic comparison, BC (black carbon aerosol) concentrations simulated by GRAPES-CUACE were generally consistent with observations from Nanjiao (one urban observation station) and Shangdianzi (one rural observation station) stations. To track the most influential emission-sources regions and the most influential time intervals for the high BC concentration during the simulation period, the adjoint model was adopted to simulate the sensitivity of average BC concentration over Beijing at the highest concentration time point (referred to as the Objective Function) with respect to BC emission amount over Beijing-Tianjin-Hebei region. Four types of regions were selected based on administrative division and sensitivity coefficient distribution. The adjoint model was used to quantify the effects of emission-sources reduction in different time intervals over different regions by one independent simulation. Effects of different emission reduction strategies based on adjoint sensitivity information show that the more influential regions (regions with relatively larger sensitivity coefficients) do not necessarily correspond to the administrative regions, and the influence effectiveness of sensitivity-oriented regions was greater than the administrative divisions. The influence of emissions on the objective function decreases sharply approximately for the pollutants emitted 17-18 h ago in this episode. Therefore, controlling critical emission regions during critical time intervals on the basis of adjoint sensitivity analysis is much more efficient than controlling administrative specified regions during an experiential time period.

  1. Full Simulation of the New Generation Windowless Large Area Silicon-Box for SIRIUS-S3

    International Nuclear Information System (INIS)

    The SPIRAL2 major installation is built in order to study rare elements through production of radioactive isotopes. Its injector, a superconducting linear accelerator (LINAC) is designed to provide very high intensity deuteron and stables beams up to ∼ 1014 part/s for ions between carbon and uranium. The 'Super Separator Spectrometer' (S3) was designed to separate and mass-analyse recoils from the various induced fusion-evaporation reactions in order to enable nuclear structure studies of proton-rich rare isotopes around 100Sn and in the Super Heavy Elements region. A new optimized focal plan detection system called SIRIUS for 'Spectroscopy and Identification of Rare Isotopes Using S3' is developed within the SIRIUS collaboration. The new generation windowless large area silicon-box developed in this framework is discussed in this article. We present the simulations done in order to determine the best geometry and layout for this large area silicon detector assembly. (authors)

  2. Plasma texturing on large-area industrial grade CZ silicon solar cells

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Nordseth, Ørnulf; Boisen, Anja;

    2013-01-01

    , and thus holds a significant potential for improvement of the cell performance compared to current industrial standards. The reflectance is shown to remain below that of conventional textured cells also at high angle of incidence. The process is shown to be equally applicable to mono-, multi- and...... quasi-mono-crystalline Si. The process was successfully integrated in fabrication of solar cells using only industry standard processes on a Czochralski (CZ) silicon starting material. The resulting cell performance was compared to cells with conventional texturing. For cells, where the nanostructuring...

  3. Study and Development of a novel Silicon Pixel Detector for the Upgrade of the ALICE Inner Tracking System

    CERN Document Server

    van Hoorn, Jacobus Willem; Riedler, Petra

    ALICE (A Large Ion Collider Experiment) is the heavy-ion experiment at the CERN Large Hadron Collider (LHC). As an important part of its upgrade plans, the ALICE experiment schedules the installation of a new Inner Tracking System (ITS) during the Long Shutdown 2 (LS2) of the LHC in 2019/20. The new ITS will consist of seven concentric layers, covering about 10m2 with Monolithic Active Pixel Sensors (MAPS). This choice of technology has been guided by the tight requirements on the material budget of 0.3 % x/X0 per layer for the three innermost layers and backed by the significant progress in the field of MAPS in recent years. The pixel chips are manufactured in the TowerJazz 180 nm CMOS process on wafers with a high-resistivity epitaxial layer on top of the substrate. During the R&D phase several chip architectures have been investigated, which take full advantage of a particular process feature, the deep p-well, that allows for full CMOS circuitry within the pixel matrix while retaining full charge colle...

  4. Identification of critical areas of carotid stent navigation by measurement of resistive forces in vitro, using silicone phantoms

    International Nuclear Information System (INIS)

    Manipulation of surgical tools in neuro-endovascular surgery presents problems that are unique to this procedure. Navigating tools through arterial complexities without appropriate visual or force feedback information often causes tool snagging, plaque dislocations and formation of thrombosis from the damage of the arterial wall by the tools. Identifying the critical areas in the vasculature during navigation of endovascular tools, will not only ensure safer surgical planning but also reduce risks of vessel damage. In the present research, resistive forces of stent navigation were measured in-vitro using silicone phantoms and clinically relevant surgical devices. The patterns of variation of the forces along the path of the stent movement were analyzed and mapped along the path of stent movement using a color code. It was observed that the forces changed along the length of the vessel, independent of the insertion length but based on the curvature of the vessel and the contact area of the device in the vessel lumen. (orig.)

  5. Distinction between the Youngest Toba Tuff and Oldest Toba Tuff from northern Sumatra based on the area density of spontaneous fission tracks in their glass shards

    Science.gov (United States)

    Westgate, John A.; Pearce, Nicholas J. G.; Gatti, Emma; Achyuthan, Hema

    2014-09-01

    Determination of the area density of spontaneous fission tracks (ρs) in glass shards of Toba tephra is a reliable way to distinguish between the Youngest Toba Tuff (YTT) and the Oldest Toba Tuff (OTT). The ρs values for YTT, uncorrected for partial track fading, range from 70 to 181 tracks/cm2 with a weighted mean of 108 ± 5 tracks/cm2, based on 15 samples. Corrected ρs values for YTT are in the range of 77-140 tracks/cm2 with a weighted mean of 113 ± 8 tracks/cm2, within the range of uncorrected ρs values. No significant difference in ρs exists between YTT samples collected from marine and continental depositional settings. The uncorrected ρs for OTT is 1567 tracks/cm2 so that confusion with YTT is unlikely. The ρs values of the Toba tephra at Bori, Morgaon, and Gandhigram in northwestern India indicate a YTT identity, in agreement with geochemical data on their glass shards, the presence of multiple glass populations, and a glass fission-track age determination. Therefore, the view of others that OTT is present at these sites - and thereby indicates a Lower Pleistocene age for the associated Acheulean artifacts - is incorrect.

  6. Development of wide area tracking method for augmented reality using multi-range fiducials

    International Nuclear Information System (INIS)

    A new fiducial marker for augmented reality was designed along with a method that recognizes the markers captured by a camera and calculates the relative position and orientation between the markers and the camera. These markers can be used at both long and short distances without increasing the number of markers pasted in the environment. Results of the experimental evaluation show that the new marker can be used in a larger area than circular markers and more stably than square markers. (author)

  7. Wide area tracking method for augmented reality supporting nuclear power plant maintenance work

    International Nuclear Information System (INIS)

    A new fiducial marker for augmented reality was designed along with a method that recognizes the markers captured by a camera and calculates the relative position and orientation between the markers and the camera. These markers can be used at both long and short distances without increasing their number in the environment. Results of the experimental evaluation show that the new marker can be used in a larger area than legacy markers such as square markers and circular markers. (author)

  8. Isotopic Tracking of Hanford 300 Area Derived Uranium in the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, John N.; Dresel, P. Evan; Conrad, Mark E.; Patton, Gregory W.; DePaolo, Donald J.

    2010-10-31

    Our objectives in this study are to quantify the discharge rate of uranium (U) to the Columbia River from the Hanford Site's 300 Area, and to follow that U down river to constrain its fate. Uranium from the Hanford Site has variable isotopic composition due to nuclear industrial processes carried out at the site. This characteristic makes it possible to use high-precision isotopic measurements of U in environmental samples to identify even trace levels of contaminant U, determine its sources, and estimate discharge rates. Our data on river water samples indicate that as much as 3.2 kg/day can enter the Columbia River from the 300 Area, which is only a small fraction of the total load of dissolved natural background U carried by the Columbia River. This very low-level of Hanford derived U can be discerned, despite dilution to < 1 percent of natural background U, 350 km downstream from the Hanford Site. These results indicate that isotopic methods can allow the amounts of U from the 300 Area of the Hanford Site entering the Columbia River to be measured accurately to ascertain whether they are an environmental concern, or are insignificant relative to natural uranium background in the Columbia River.

  9. Isotopic Tracking of Hanford 300 Area Derived Uranium in the Columbia River

    International Nuclear Information System (INIS)

    Our objectives in this study are to quantify the discharge rate of uranium (U) to the Columbia River from the Hanford Site's 300 Area, and to follow that U down river to constrain its fate. Uranium from the Hanford Site has variable isotopic composition due to nuclear industrial processes carried out at the site. This characteristic makes it possible to use high-precision isotopic measurements of U in environmental samples to identify even trace levels of contaminant U, determine its sources, and estimate discharge rates. Our data on river water samples indicate that as much as 3.2 kg/day can enter the Columbia River from the 300 Area, which is only a small fraction of the total load of dissolved natural background U carried by the Columbia River. This very low-level of Hanford derived U can be discerned, despite dilution to < 1 percent of natural background U, 350 km downstream from the Hanford Site. These results indicate that isotopic methods can allow the amounts of U from the 300 Area of the Hanford Site entering the Columbia River to be measured accurately to ascertain whether they are an environmental concern, or are insignificant relative to natural uranium background in the Columbia River.

  10. The impact of a fast track area on quality and effectiveness outcomes: a Middle Eastern emergency department perspective.

    LENUS (Irish Health Repository)

    Devkaran, Subashnie

    2009-01-01

    BACKGROUND: Emergency department (ED) overcrowding is a ubiquitous problem with serious public health implications. The fast track area is a novel method which aims to reduce waiting time, patient dissatisfaction and morbidity. |The study objective was to determine the impact of a fast track area (FTA) on both effectiveness measures (i.e. waiting times [WT] and length of stay [LOS]) and quality measures (i.e. LWBS rates and mortality rates) in non-urgent patients. The secondary objective was to assess if a FTA negatively impacted on urgent patients entering the ED. METHODS: The study took place in a 500 bed, urban, tertiary care hospital in Abu Dhabi, United Arab Emirates. This was a quasi-experimental, which examined the impact of a FTA on a pre-intervention control group (January 2005) (n = 4,779) versus a post-intervention study group (January 2006) (n = 5,706). RESULTS: Mean WTs of Canadian Triage Acuity Scale (CTAS) 4 patients decreased by 22 min (95% CI 21 min to 24 min, P < 0.001). Similarly, mean WTs of CTAS 5 patients decreased by 28 min (95% CI 19 min to 37 min, P < 0.001) post FTA. The mean WTs of urgent patients (CTAS 2\\/3) were also significantly reduced after the FTA was opened (P < 0.001). The LWBS rate was reduced from 4.7% to 0.7% (95% CI 3.37 to 4.64; P < 0.001). Opening a FTA had no significant impact on mortality rates (P = 0.88). CONCLUSION: The FTA improved ED effectiveness (WTs and LOS) and quality measures (LWBS rates) whereas mortality rate remained unchanged.

  11. Large-area silica nanotubes with controllable geometry on silicon substrates

    Science.gov (United States)

    Hu, Mingzhe; Yu, Rong; MacManus-Driscoll, Judith L.; Robinson, Adam P.

    2009-01-01

    The synthesis of a highly uniform, large-scale nanoarrays consisting of silica nanotubes above embedded nanohole arrays in silicon substrates is demonstrated. In situ anodized aluminium oxide (AAO) thin film masks on Si substrates were employed, and the nanotubes were fabricated by Ar ion milling through the masks. The geometries of the nanoarrays, including pore diameter, interpore distance and the length of both nanopores and nanotubes could be controlled by the process parameters, which included that the outer pore diameter of silica tube was tuned from ˜80 nm to ˜135 nm while the inner tube diameter from ˜40 nm to ˜65 nm, the interpore distance of the nanotube arrays was from 100 nm to 180 nm and the length of silica tube changed from ˜90 nm to ˜250 nm. The presented nanostructure fabrication method has strong potential for application in intensity and frequency adjustable high luminescence efficiency optoelectronic devices.

  12. Closure Report for Corrective Action Unit 539: Areas 25 and 26 Railroad Tracks Nevada National Security Site, Nevada, Revision 0

    International Nuclear Information System (INIS)

    This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 539: Areas 25 and 26 Railroad Tracks, Nevada National Security Site, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. The corrective action sites (CASs) within CAU 539 are located within Areas 25 and 26 of the Nevada National Security Site. Corrective Action Unit 539 comprises the following CASs: (1) 25-99-21, Area 25 Railroad Tracks; and (2) 26-99-05, Area 26 Railroad Tracks The purpose of this CR is to provide documentation supporting the completed corrective actions and provide data confirming that the closure objectives for CASs within CAU 539 were met. To achieve this, the following actions were performed: (1) Reviewed documentation on historical and current site conditions, including the concentration and extent of contamination; (2) Conducted radiological walkover surveys of railroad tracks in both Areas 25 and 26; (3) Collected ballast and soil samples and calculated internal dose estimates for radiological releases; (4) Collected in situ thermoluminescent dosimeter measurements and calculated external dose estimates for radiological releases; (5) Removed lead bricks as potential source material (PSM) and collected verification samples; (6) Implemented corrective actions as necessary to protect human health and the environment; (7) Properly disposed of corrective action and investigation wastes; and (8) Implemented an FFACO use restriction (UR) for radiological contamination at CAS 25-99-21. The approved UR form and map are provided in Appendix F and will be filed in the DOE, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), Facility Information Management System; the FFACO database; and the NNSA/NSO CAU/CAS files. From

  13. Characterization of environmental gamma radiation in urban areas using a tracking mobile unit

    International Nuclear Information System (INIS)

    The air kerma rate was determined for the main areas in the monazite sand region of the Guarapari city, along the Brazilian coast, and for the volcanic intrusives of the Pocos de Caldas Plateau, inland of Brazil, by using a carborne environmental survey unit. The unit is composed of two gamma spectrometry systems connected to a 100 ml and 4000 ml NaI(Tl) crystal detectors respectively. Both detectors response functions were determined by Monte Carlo simulation with the EGS4 computer code; the conversion coefficients to air kerma cover the environmental range, from 40 up to 3000 keV, split into ten energy bands. The detector response function were validated by experimental measurements of known gamma fields due to both punctual and large concrete sources; the point sources were measured using the shadow shield technique to account for floor and ceiling scattering, and the outdoors large radioactive concrete sources were of 3 m diameter covering a wide range of common environmental gamma fields. The correction factor to account for the shielding due to the vehicle was determined only experimentally. The average air kerma rates obtained at the main urban areas of the towns in the Pocos de Caldas Plateau were: Aguas da Prata, 105.6 nGy/h; Andradas 98.5 nGy/h; Caldas, 128.2 nGy/h; Pocos de Caldas, 144.46 nGy/h. No high air kerma rate spots were found. The mean value for the air kerma rate at the urban region of Guarapari, was 88.9 nGy/h. In this region were found 28 occurrences of small monazite patches, varing from 300 to 6000 nGy/h. (author)

  14. The STAR tracking upgrade

    International Nuclear Information System (INIS)

    The STAR experiment at the Relativistic Heavy Ion Collider RHIC studies the new state of matter produced in relativistic heavy ion collisions and the spin structure of the nucleon in collisions of polarized protons. In order to improve the capabilities for heavy flavor measurements and the reconstruction of charged vector bosons an upgrade of the tracking system both in the central and the forward region is pursued. The challenging environments of high track multiplicity in heavy ion collisions and of high luminosity in polarized proton collisions require the use of new technologies. The proposed inner tracking system, optimized for heavy flavor identification, is using active pixel sensors close to the collision point and silicon strip technology further outward. Charge sign determination for electrons and positrons from the decay of W bosons will be provide by 6 large-area triple GEM disks currently under development. A prototype of the active pixel detectors has been tested in the STAR experiment, and an extensive beam test of triple GEM detectors using GEM foils produced by Tech-Etch of Plymouth, MA has been done at Fermilab

  15. Area tracking in topographical in-vivo measurement series of human skin by displacement vector fields

    Science.gov (United States)

    Hopermann, Hermann; Lunderstaedt, Reinhart A.

    2000-12-01

    In the first part of the presented paper a new measurement system for fast three-dimensional in vivo measurement of the microtopography of human skin is proposed. It is based on the principle of active image triangulation. A Digital Micromirror Device (DMDTM) is used for projecting sinusoidal intensity distributions on the surface of human skin. By using temporal phase shift algorithms the three-dimensional topography is reconstructed from two-dimensional images. Displacement vector fields represent a promising approach for detecting deformation and other lateral changes in the surface of human skin. In the second part of the presented paper a method based on local template matching and smooth interpolation algorithms for determining a displacement vector field is proposed. Aiming at a minimal expenditure of numerical calculation, a stepwise algorithm was developed for this purpose. The deformatory component of the calculated vector field is separated by minimizing a suitable functional, which is also presented in the paper. In investigations of measurement series the proposed method proves to be very efficient. The calculated displacement vector fields connect corresponding areas in two subsequent measurements. Distortions caused by mechanical deformation or other influences can be detected and visualized by the separated deformatory components of the vector fields.

  16. RESULTS OF TRITIUM TRACKING AND GROUNDWATER MONITORING AT THE HANFORD SITE 200 AREA STATE APPROVED LAND DISPOSAL SITE FY2008

    Energy Technology Data Exchange (ETDEWEB)

    ERB DB

    2008-11-19

    The Hanford Site's 200 Area Effluent Treatment Facility (ETF) processes contaminated aqueous wastes derived from Hanford Site facilities. The treated wastewater occasionally contains tritium, which cannot be removed by the ETF prior to the wastewater being discharged to the 200 Area State-Approved Land Disposal Site (SALDS). During the first 11 months of fiscal year 2008 (FY08) (September 1, 2007, to July 31, 2008), approximately 75.15 million L (19.85 million gal) of water were discharged to the SALDS. Groundwater monitoring for tritium and other constituents, as well as water-level measurements, is required for the SALDS by State Waste Discharge Permit Number ST-4500 (Ecology 2000). The current monitoring network consists of three proximal (compliance) monitoring wells and nine tritium-tracking wells. Quarterly sampling of the proximal wells occurred in October 2007 and in January/February 2008, April 2008, and August 2008. The nine tritium-tracking wells, including groundwater monitoring wells located upgradient and downgradient of the SALDS, were sampled in January through April 2008. Water-level measurements taken in the three proximal SALDS wells indicate that a small groundwater mound is present beneath the facility, which is a result of operational discharges. The mound increased in FY08 due to increased ETF discharges from treating groundwater from extraction wells at the 200-UP-l Operable Unit and the 241-T Tank Farm. Maximum tritium activities increased by an order of magnitude at well 699-48-77A (to 820,000 pCi/L in April 2008) but remained unchanged in the other two proximal wells. The increase was due to higher quantities of tritium in wastewaters that were treated and discharged in FY07 beginning to appear at the proximal wells. The FY08 tritium activities for the other two proximal wells were 68,000 pCi/L at well 699-48-77C (October 2007) and 120,000 pCi/L at well 699-48-77D (October 2007). To date, no indications of a tritium incursion from

  17. Clean graphene interfaces by selective dry transfer for large area silicon integration

    Science.gov (United States)

    Na, S. R.; Rahimi, S.; Tao, L.; Chou, H.; Ameri, S. K.; Akinwande, D.; Liechti, K. M.

    2016-03-01

    Here we present a very fast, selective mechanical approach for transferring graphene with low levels of copper contamination from seed wafers on which it was grown to target wafers for very large scale integration (VLSI) electronics. We found that graphene/copper or copper/silicon oxide delamination paths could be selected by slow and faster separation rates, respectively. Thus graphene can be transferred to a target wafer, either exposed or protected by the seed copper layer, which can later be removed by etching. Delamination paths were identified by SEM and Raman spectroscopy. The sheet resistance of the graphene produced by the two approaches was slightly higher than graphene transferred by a PMMA wet-transfer process, indicating reduced impurity doping, and the variation in the sheet resistance values was much lower. Copper contamination levels, quantitatively established by TOF-SIMS, were several orders of magnitude lower than the values for PMMA assisted transfer. In addition, we demonstrated that top-gated transistor devices from our mechanical, delamination transferred graphene exhibited superior transistor behavior to PMMA-assisted wet transfer graphene. The adhesion energy, strength and range of the interactions were quantitatively determined by nonlinear fracture analyses, and suggest that the roughness of the interface between graphene and copper plays an important role with implications for improvements in manufacturing processes.Here we present a very fast, selective mechanical approach for transferring graphene with low levels of copper contamination from seed wafers on which it was grown to target wafers for very large scale integration (VLSI) electronics. We found that graphene/copper or copper/silicon oxide delamination paths could be selected by slow and faster separation rates, respectively. Thus graphene can be transferred to a target wafer, either exposed or protected by the seed copper layer, which can later be removed by etching

  18. Large Area Silicon Tracking Detectors with Fast Signal Readout for the Large Hadron Collider (LHC) at CERN

    CERN Document Server

    Köstner, S

    2005-01-01

    The Standard Model of elementary particles, which is summarized briefly in the second chapter, incorporates a number of successful theories to explain the nature and consistency of matter. However not all building blocks of this model could yet be tested by experiment. To confirm existing theories and to improve nowadays understanding of matter a new machine is currently being built at CERN, the Large Hadron Collider (LHC), described in the third chapter. LHC is a proton-proton collider which will reach unprecedented luminosities and center of mass energies. Five experiments are attached to it to give answers to questions like the existence of the Higgs meson, which allows to explain the mass content of matter, and the origin of CP-violation, which plays an important role in the baryogenesis of the universe. Supersymmetric theories, proposing a bosonic superpartner for each fermion and vice versa, will be tested. By colliding heavy ions, high energy and particle densities can be achieved and probed. This stat...

  19. Implementing telemetry on new species in remote areas: Recommendations from a large-scale satellite tracking study of African waterfowl

    Science.gov (United States)

    Cappelle, J.; Iverson, S.A.; Takekawa, J.Y.; Newman, S.H.; Dodman, T.; Gaidet, N.

    2011-01-01

    We provide recommendations for implementing telemetry studies on waterfowl on the basis of our experience in a tracking study conducted in three countries of sub-Saharan Africa. The aim of the study was to document movements by duck species identified as priority candidates for the potential spread of avian influenza. Our study design included both captive and field test components on four wild duck species (Garganey, Comb Duck, White-faced Duck and Fulvous Duck). We used our location data to evaluate marking success and determine when signal loss occurred. The captive study of eight ducks marked with non-working transmitters in a zoo in Montpellier, France, prior to fieldwork showed no evidence of adverse effects, and the harness design appeared to work well. The field study in Malawi, Nigeria and Mali started in 2007 on 2 February, 6 February and 14 February, and ended on 22 November 2007 (288 d), 20 January 2010 (1 079 d), and 3 November 2008 (628 d), respectively. The field study indicated that 38 of 47 (81%) of the platform transmitter terminals (PTTs) kept transmitting after initial deployment, and the transmitters provided 15 576 locations. Signal loss during the field study was attributed to three main causes: PTT loss, PTT failure and mortality (natural, human-caused and PTT-related). The PTT signal quality varied by geographic region, and interference caused signal loss in the Mediterranean Sea region. We recommend careful attention at the beginning of the study to determine the optimum timing of transmitter deployment and the number of transmitters to be deployed per species. These sample sizes should be calculated by taking into account region-specific causes of signal loss to ensure research objectives are met. These recommendations should be useful for researchers undertaking a satellite tracking program, especially when working in remote areas of Africa where logistics are difficult or with poorly-known species. ?? NISC (Pty) Ltd.

  20. Mesozoic-Cenozoic tectonic evolution and its relation to sandstone-type uranium mineralization in northern Tarim area--Evidence from apatite fission track

    International Nuclear Information System (INIS)

    The apatite fission track dating and inversion result of geological thermal history of four rock specimens from Sawafuqi area and Talike area in northern Tarim Basin show that two areas uplifted at different ages. The apatite fission track ages of Sawafuqi range from 3.5 to 3.9 Ma, while the ages of Talike range from 53 to 59 Ma. The thermal history recorded by rock samples reveals that there are at least three prominent cooling phases since Late Cretaceous epoch. Detailed study was made on the division of uplifting stages during Mesozoic and Cenozoic tectonic evolution with the existing data in northern Tarim area. And new ideas on tectonic evolution and sandstone-type uranium mineralization have been put forward by combining with the sandstone-type uranium mineralization ages in this area.(authors)

  1. Large-Area, UV-Optimized, Back-Illuminated Silicon Photomultiplier Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Large-area (3m2), UV-sensitive focal plane arrays are needed for observation of air showers from ultra-high energy cosmic rays (JEM-EUSO) as well as for...

  2. Tracking and Alignment in the CMS detector

    CERN Document Server

    Ronga, Frederic Jean

    2007-01-01

    This Report summarises the alignment strategy of the CMS detector. Track reconstruction in the silicon tracker and muon chambers is briefly described. We then present the different sources of alignment information, in particular alignment algorithms using reconstructed tracks.

  3. Tracking Crop Leaf Area Index and Chlorophyll Content Using RapidEye Data in Northern Ontario, Canada

    Science.gov (United States)

    Shang, J.; Liu, J.; Ma, B.; Zhao, T.; Kovacs, J. M.; Jiao, X.; Dong, T.; Huffman, T.; Geng, X.; Walters, D.

    2014-12-01

    Information on crop phenological state such as flowering, maturing, drying, senescence, and harvesting is essential for crop production surveillance and yield prediction. Earth Observation data provide an important information source for monitoring crop development at various temporal and spatial scales. In particular, the availability of many high-spatial-resolution space sensors offers a powerful tool for precision farming. This study reports the results of a two-year (2012, 2013) study over spring wheat and canola fields using six different vegetation indices derived from the high-resolution (6.5m) RapidEye optical satellite data in northern Ontario, Canada. The study revealed that for both wheat and canola, significant relationships were observed between the ground-derived leaf area index (LAI) and all 6 vegetation indices tested. For spring wheat, the strongest relationship was found between LAI and the Modified Triangular Vegetation Index 2 (MTVI2), with a coefficient of determination (R2) of 0.95. For canola, a R2 of 0.92 was achieved. Strong relationships were also found between all six vegetation indices and the chlorophyll concentration index (CCI) measured in the fields using a CCM-200 device. The strongest correlation exists between CCI and the ratio of Modified the Chlorophyll Absorption Reflected Index (MCARI) and the Optimized Soil Adjusted Vegetation Index (OSAVI), with an R2 of 0.86. It suggests that RapidEye data can be used to track field-scale crop LAI and monitor crop chlorophyll content.

  4. Single-grain Silicon Technology for Large Area X-ray Imaging

    OpenAIRE

    Arslan, A

    2015-01-01

    Digital flat panel X-ray imagers are currently using a-Si and poly-Si thin-film-transistors (TFTs). a-Si TFT permits the use of large area substrates, however, due to the amorphous nature, the carrier mobility is very low (

  5. Single-grain Silicon Technology for Large Area X-ray Imaging

    NARCIS (Netherlands)

    Arslan, A.

    2015-01-01

    Digital flat panel X-ray imagers are currently using a-Si and poly-Si thin-film-transistors (TFTs). a-Si TFT permits the use of large area substrates, however, due to the amorphous nature, the carrier mobility is very low (<1 cm2/Vs). Poly-Si TFT improves the mobility (~150 cm2/Vs) but due to random

  6. Stanols as a tool to track the origin of microbial contamination of oysters, Crassostrea gigas, in shellfish areas.

    Science.gov (United States)

    Harrault, Loïc; Jardé, Emilie; Jeanneau, Laurent; Petitjean, Patrice

    2013-04-01

    Runoff of cattle manures (cows, pigs, sheeps) or discharge of effluent from wastewater treatment plants (WWTP) into aquatic ecosystems can lead to microbiological contamination of waters and living organisms. In coastal ecosystems and particularly in shellfish harvesting areas, the presence of pathogen microorganisms in waters induces fecal contamination of filter feeding bivalves (oysters, mussels, scallops…), therefore leading to human health risks associated to the consumption of these contaminated organisms. Watershed management plans that aim at limiting these risks require the development of tools able to identify fecal contamination sources. The fecal indicator bacteria used in the regulations to determine fecal contamination are not source specific since they are found in the feces of most warm-blooded animals. Thus, microbiological biomarkers have been developed in association with chemical biomarkers as Microbial Source Tracking (MST) methods. Fecal stanols, by-products of sterols obtained by human and animal microbial gut flora, are found in considerable amounts in feces with different relative proportions depending on their animal or human source. Recently, in association with microbiological biomarkers, the stanol fingerprint of contaminated waters has been successfully used to determine the main source of fecal contamination (cow, pig or human sources) in rural watersheds (Brittany, France). Up to now, the use of the stanol fingerprint to track the fecal contamination in shellfish tissues, especially bivalves, has been limited to the analysis of coprostanol, a stanol commonly associated to human contamination. Therefore, whether the stanol fingerprint can be used as a MST method in bivalves or not is still unknown. The first aim of this study was to compare several organic extraction procedures of stanols in the oyster Crassostrea gigas to determine a reliable method for stanol fingerprint analysis in bivalves. Solvent extraction and purification

  7. Microfabrication of large-area circular high-stress silicon nitride membranes for optomechanical applications

    Directory of Open Access Journals (Sweden)

    E. Serra

    2016-06-01

    Full Text Available In view of the integration of membrane resonators with more complex MEMS structures, we developed a general fabrication procedure for circular shape SiNx membranes using Deep Reactive Ion Etching (DRIE. Large area and high-stress SiNx membranes were fabricated and used as optomechanical resonators in a Michelson interferometer, where Q values up to 1.3 × 106 were measured at cryogenic temperatures, and in a Fabry-Pérot cavity, where an optical finesse up to 50000 has been observed.

  8. Near-infrared electroluminescence and photo detection in InGaAs p-i-n microdisks grown by selective area growth on silicon

    International Nuclear Information System (INIS)

    Microselective-area growth of p-i-n InGaAs disks on (111) silicon by metalorganic chemical vapor deposition is a promising technology for III/V-on-Si integration. As a proof-of-concept, room-temperature electroluminescence is reported from ensembles of p-i-n InGaAs-on-Si micro-disks. The observed spectrum shows peak luminescence at 1.78 μm with a local maxima at 1.65 μm. The disks are also shown to generate a measurable photo current when illuminated by infrared light with less energy than the silicon bandgap energy. This makes these InGaAs-on-Si disks a promising technology for monolithic integration of light sources and detectors with silicon photonics and complementary metal-oxide-semiconductor electronics for optical communication, sensing, and imaging.

  9. Printed Large-Area Single-Mode Photonic Crystal Bandedge Surface-Emitting Lasers on Silicon.

    Science.gov (United States)

    Zhao, Deyin; Liu, Shihchia; Yang, Hongjun; Ma, Zhenqiang; Reuterskiöld-Hedlund, Carl; Hammar, Mattias; Zhou, Weidong

    2016-01-01

    We report here an optically pumped hybrid III-V/Si photoic crystal surface emitting laser (PCSEL), consisting of a heterogeneously integrated III-V InGaAsP quantum well heterostructure gain medium, printed on a patterned defect-free Si photonic crystal (PC) bandedge cavity. Single mode lasing was achieved for a large area laser, with a side-mode suppression ratio of 28 dB, for lasing operation temperature ~ 200 K. Two types of lasers were demonstrated operating at different temperatures. Detailed modal analysis reveals the lasing mode matches with the estimated lasing gain threshold conditions. Our demonstration promises a hybrid laser sources on Si towards three-dimensional (3D) integrated Si photonics for on-chip wavelength-division multiplex (3D WDM) systems for a wide range of volume photonic/electronic applications in computing, communication, sensing, imaging, etc. PMID:26727551

  10. Printed Large-Area Single-Mode Photonic Crystal Bandedge Surface-Emitting Lasers on Silicon

    Science.gov (United States)

    Zhao, Deyin; Liu, Shihchia; Yang, Hongjun; Ma, Zhenqiang; Reuterskiöld-Hedlund, Carl; Hammar, Mattias; Zhou, Weidong

    2016-01-01

    We report here an optically pumped hybrid III-V/Si photoic crystal surface emitting laser (PCSEL), consisting of a heterogeneously integrated III-V InGaAsP quantum well heterostructure gain medium, printed on a patterned defect-free Si photonic crystal (PC) bandedge cavity. Single mode lasing was achieved for a large area laser, with a side-mode suppression ratio of 28 dB, for lasing operation temperature ~200 K. Two types of lasers were demonstrated operating at different temperatures. Detailed modal analysis reveals the lasing mode matches with the estimated lasing gain threshold conditions. Our demonstration promises a hybrid laser sources on Si towards three-dimensional (3D) integrated Si photonics for on-chip wavelength-division multiplex (3D WDM) systems for a wide range of volume photonic/electronic applications in computing, communication, sensing, imaging, etc.

  11. Tunnel oxide passivated rear contact for large area n-type front junction silicon solar cells providing excellent carrier selectivity

    Directory of Open Access Journals (Sweden)

    Yuguo Tao

    2016-01-01

    Full Text Available Carrier-selective contact with low minority carrier recombination and efficient majority carrier transport is mandatory to eliminate metal-induced recombination for higher energy conversion efficiency for silicon (Si solar cells. In the present study, the carrier-selective contact consists of an ultra-thin tunnel oxide and a phosphorus-doped polycrystalline Si (poly-Si thin film formed by plasma enhanced chemical vapor deposition (PECVD and subsequent thermal crystallization. It is shown that the poly-Si film properties (doping level, crystallization and dopant activation anneal temperature are crucial for achieving excellent contact passivation quality. It is also demonstrated quantitatively that the tunnel oxide plays a critical role in this tunnel oxide passivated contact (TOPCON scheme to realize desired carrier selectivity. Presence of tunnel oxide increases the implied Voc (iVoc by ~ 125 mV. The iVoc value as high as 728 mV is achieved on symmetric structure with TOPCON on both sides. Large area (239 cm2 n-type Czochralski (Cz Si solar cells are fabricated with homogeneous implanted boron emitter and screen-printed contact on the front and TOPCON on the back, achieving 21.2% cell efficiency. Detailed analysis shows that the performance of these cells is mainly limited by boron emitter recombination on the front side.

  12. Large Area Silicon Carbide Vertical JFETs for 1200 V Cascode Switch Operation

    Directory of Open Access Journals (Sweden)

    Victor Veliadis

    2008-01-01

    Full Text Available SiC VJFETs are excellent candidates for reliable high-power/temperature switching as they only use pn junctions in the active device area where the high-electric fields occur. VJFETs do not suffer from forward voltage degradation, exhibit excellent short-circuit performance, and operate at 300°C. 0.19 cm2 1200 V normally-on and 0.15 cm2 low-voltage normally-off VJFETs were fabricated. The 1200-V VJFET outputs 53 A with a forward drain voltage drop of 2 V and a specific onstate resistance of 5.4 mΩ cm2. The low-voltage VJFET outputs 28 A with a forward drain voltage drop of 3.3 V and a specific onstate resistance of 15 mΩ cm2. The 1200-V SiC VJFET was connected in the cascode configuration with two Si MOSFETs and with a low-voltage SiC VJFET to form normally-off power switches. At a forward drain voltage drop of 2.2 V, the SiC/MOSFETs cascode switch outputs 33 A. The all-SiC cascode switch outputs 24 A at a voltage drop of 4.7 V.

  13. Silicon carbide bodies

    International Nuclear Information System (INIS)

    A self-bonded silicon carbide body produced by siliconising a preformed mixture of particles (shaped by means other than slip-casting) of carbon and silicon carbide in the beta form has a mean grain size in the range of 0.1 to 5 microns. Such a body may be produced using silicon carbide particles having a mean surface area in the range 0.5 to 20 square metres per gram. The silicon carbide particles may be produced by heating a mixture of silica and silicon to generate silicon monoxide vapour and passing the vapour through a bed of particulate carbon. (author)

  14. Hydrological and Physical Characterization of Cinque Terre Marine Protected Area (Ligurian Sea) and Evaluation of Current Velocity and Direction by AUV Navigation Tracks

    OpenAIRE

    Locritani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Chiappini, O.; NATO Undersea Research Centre, La Spezia, Italy; Chiarabini, R.; NATO Undersea Research Centre, La Spezia, Italy; Bruni, F.; Tecnomare S.p.A.; Ciccarelli, V.; Tecnomare S.p.A.; Natale, L.; Parco Nazionale delle Cinque Terre, La Spezia, Italy; De Paulis, R.; ENI exploration and production division, GEOLAB Dept., Milano, Italy

    2010-01-01

    The integrated study, concerning the experimental observations, was performed during the oceanographic cruises on-board the two NURC research vessels, in the period between 2008 and 2010 in the Marine Protected Area of Cinque Terre (North-West Mediterranean Sea, Italy). The aim of the research is to describe the environmental features using both hydrological parameters and AUV navigation tracks, acquired respectively by a multi-parametric platform (MEDUSA) and AUV MUSCLE. The innovat...

  15. Apatite fission track analysis for revealing tectonic events of the Bayinguole area in the west section of Eastern Kunlun Mountains, northern Qinghai-Tibet Plateau

    International Nuclear Information System (INIS)

    Background: Qimantage is an important tectonic metallogenic belt in western part of East Kunlun Mountain. It has experienced complex geological evolution, and significant mineralization. However, because of the plateau climate and inaccessibility, fewer research works have been done on this area, especially after Indo-sinian epoch. Purpose: Our work is to research tectonic activity, thermal history and uplifting around Bayinguole river in Qimantage belt. Methods: The apatite fission-track method was applied to research the tectonic setting, simulate the thermal history and calculate the uplift size and uplift speed. Results: A series of apatite fission track ages from granitoid samples in Bayinguole area of Eastern Kunlun Mountain were obtained, ranging from 120 Ma to 47 Ma that might be divided into three groups': 120-100 Ma, 67 Ma and 54-47 Ma. These ages reflected tectonic events in this area very well. Conclusions: The 120-100 Ma and 67 Ma ages present collision-convergences of Gangdese terrane and Himalayan terrane with their north-side terranes in Early Cretaceous and Late Cretaceous respectively. The ages of 54-47 Ma reflect post-orogenic stretching events in Eocene. Three stages of thermal evolution history are revealed by apatite fission track modeling in this area. Stage one 180-140 Ma is in the bottom temperature of apatite fission track anneal zone. Stage two 140-13 Ma records slow cooling. The last stage after 13 Ma records rapid cooling with temperature dropped 50℃. The uplifting ranges for these three stages are 1.0 km, 0.6 km and 1.4 km, respectively. The cumulative amount of uplift is about 3.0 km. The formula calculations for the 3 samples have their rock uplifts of 3623 m, 3317 m and 3769 m, respectively, averaging 3570 m, in accordance with the results based on the 3 stage thermal history. (authors)

  16. Track reconstruction at the ILC: the ILD tracking software

    International Nuclear Information System (INIS)

    One of the key requirements for Higgs physics at the International Linear Collider ILC is excellent track reconstruction with very good momentum and impact parameter resolution. ILD is one of the two detector concepts at the ILC. Its central tracking system comprises of an outer Si-tracker, a highly granular TPC, an intermediate silicon tracker and a pixel vertex detector, and it is complemented by silicon tracking disks in the forward direction. Large hit densities from beam induced coherent electron-positron pairs at the ILC pose an additional challenge to the pattern recognition algorithms. We present the recently developed new ILD tracking software, the pattern recognition algorithms that are using clustering techniques, Cellular Automatons and Kalman filter based track extrapolation. The performance of the ILD tracking system is evaluated using a detailed simulation including dead material, gaps and imperfections.

  17. Tracking objects, Tracking agents

    OpenAIRE

    Bullot, Nicolas J.; Rysiew, Patrick

    2005-01-01

    Animals and humans have to keep track of individuals in their environment, both in perception (sensorimotor tracking) and in cognition (e.g., spatio-temporal localization and linguistic reference via memory, communication and reasoning). Items that are typical targets for tracking are things such as stationary physical objects (e.g., rocks, plants, trees, buildings, or attached artifacts), moving physical objects (e.g., animals, certain artifacts) and human beings. All such items are located ...

  18. A Novel Methodology for Thermal Aware Silicon Area Estimation for 2D & 3D MPSoCs

    Directory of Open Access Journals (Sweden)

    Vinod Pangracious

    2012-01-01

    Full Text Available In a multiprocessor system on chip (MPSoC IC the processor is one of the highest heat dissipating devices. The temperature generated in an IC may vary with floor plan of the chip. This paper proposes an integration and thermal analysis methodology to extract the peak temperature and temperature distribution of 2-dimensional and 3-dimensional multiprocessor system-on-chip. As we know the peak temperature of chip increases in 3-dimensional structures compared to 2-dimensional ones due to the reduced space in intra-layer and inter-layer components. In sub-nanometre scale technologies, it is inevitable to analysis the heat developed in individual chip to extract the temperature distribution of the entire chip. With thetechnology scaling in new generation ICs more and more components are integrated to a smaller area. Along with the other parameters threshold voltage is also scaled down which results in exponential increase in leakage current. This has resulted in rise in hotspot temperature value due to increase inleakage power. In this paper, we have analysed the temperature developed in an IC with four identical processors at 2.4 GHz in different floorplans. The analysis has been done for both 2D and 3D arrangements. In the 3D arrangement, a three layered structure has been considered with two Silicon layers and a thermal interface material (TIM in between them. Based on experimental results the paperproposes a methodology to reduce the peak temperature developed in 2D and 3D integrated circuits .

  19. A Novel Methodology for Thermal Aware Silicon Area Estimation for 2D & 3D MPSoCs

    Directory of Open Access Journals (Sweden)

    Ramya Menon C

    2011-12-01

    Full Text Available In a multiprocessor system on chip (MPSoC IC the processor is one of the highest heat dissipating devices. The temperature generated in an IC may vary with floor plan of the chip. This paper proposes an integration and thermal analysis methodology to extract the peak temperature and temperature distribution of 2-dimensional and 3-dimensional multiprocessor system-on-chip. As we know the peak temperature of chip increases in 3-dimensional structures compared to 2-dimensional ones due to the reduced space in intra-layer and inter-layer components. In sub-nanometre scale technologies, it is inevitable to analysis the heat developed in individual chip to extract the temperature distribution of the entire chip. With the technology scaling in new generation ICs more and more components are integrated to a smaller area. Along with the other parameters threshold voltage is also scaled down which results in exponential increase in leakage current. This has resulted in rise in hot spot temperature value due to increase in leakage power. In this paper, we have analysed the temperature developed in an IC with four identical processors at 2.4 GHz in different floor plans. The analysis has been done for both 2D and 3D arrangements. In the 3D arrangement, a three layered structure has been considered with two Silicon layers and a thermal interface material (TIM in between them. Based on experimental results the paper proposes a methodology to reduce the peak temperature developed in 2D and 3D integrated circuits .

  20. INNER TRACKING

    CERN Multimedia

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The Objective for 2006 was to complete all of the CMS Tracker sub-detectors and to start the integration of the sub-detectors into the Tracker Support Tube (TST). The Objective for 2007 is to deliver to CMS a completed, installed, commissioned and calibrated Tracking System (Silicon Strip and Pixels) aligned to < 100µ in April 2008 ready for the first physics collisions at LHC. In November 2006 all of the sub-detectors had been delivered to the Tracker Integration facility (TIF) at CERN and the tests and QA procedures to be carried out on each sub-detector before integration had been established. In December 2006, TIB/TID+ was integrated into TOB+, TIB/TID- was being prepared for integration, and TEC+ was undergoing tests at the final tracker operating temperature (-100 C) in the Lyon cold room. In February 2007, TIB/TID- has been integrated into TOB-, and the installation of the pixel support tube and the services for TI...

  1. Exploration of maximum count rate capabilities for large-area photon counting arrays based on polycrystalline silicon thin-film transistors

    Science.gov (United States)

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

    2016-03-01

    Pixelated photon counting detectors with energy discrimination capabilities are of increasing clinical interest for x-ray imaging. Such detectors, presently in clinical use for mammography and under development for breast tomosynthesis and spectral CT, usually employ in-pixel circuits based on crystalline silicon - a semiconductor material that is generally not well-suited for economic manufacture of large-area devices. One interesting alternative semiconductor is polycrystalline silicon (poly-Si), a thin-film technology capable of creating very large-area, monolithic devices. Similar to crystalline silicon, poly-Si allows implementation of the type of fast, complex, in-pixel circuitry required for photon counting - operating at processing speeds that are not possible with amorphous silicon (the material currently used for large-area, active matrix, flat-panel imagers). The pixel circuits of two-dimensional photon counting arrays are generally comprised of four stages: amplifier, comparator, clock generator and counter. The analog front-end (in particular, the amplifier) strongly influences performance and is therefore of interest to study. In this paper, the relationship between incident and output count rate of the analog front-end is explored under diagnostic imaging conditions for a promising poly-Si based design. The input to the amplifier is modeled in the time domain assuming a realistic input x-ray spectrum. Simulations of circuits based on poly-Si thin-film transistors are used to determine the resulting output count rate as a function of input count rate, energy discrimination threshold and operating conditions.

  2. Large area multicrystalline silicon solar cells in high volume production environment - history, status, new processes, technology transfer issues

    International Nuclear Information System (INIS)

    Cast multicrystalline silicon (mc-Si) solar cell technology, accounted for nearly 41% of all the PV modules manufactures worldwide in 2000. Since 1995 the use of cast mc-Si as a substrate has increased every year and that increase is expected to accelerate in the coming years as the PV market grows further. This impressive growth has been enabled by several factors - wafer suppliers, improvements in casting technology, sawing technology and cell process technology. In this paper the enabling factors will be discussed. The new processes used to enhance the efficiency of the cast multicrystalline silicon solar cells and the criteria for technology transfer will also be discussed. (author)

  3. Mr. Lorenzo Dellai, presidente della provincia Autonoma di Trento and Professor Andrea Zanotti, president dell'Instituto Trentino di Cultura, visit ALICE experiment underground area and Pixel Silicon Laboratory

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    Mr. Lorenzo Dellai, presidente della provincia Autonoma di Trento and Professor Andrea Zanotti, president dell'Instituto Trentino di Cultura, visit ALICE experiment underground area and Pixel Silicon Laboratory

  4. The Solenoidal Detector Collaboration silicon detector system

    International Nuclear Information System (INIS)

    Silicon tracking systems will be fundamental components of the tracking systems for both planned major SSC experiments. Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. This report discusses its design and operation

  5. Hyperon production in proton-nucleus collisions at a center-of-mass energy of √(sNN) = 41.6 GeV at HERA-B and design of silicon microstrip detectors for tracking at LHCb

    International Nuclear Information System (INIS)

    The topics of this thesis are the measurements of hyperon production in protonnucleus collisions at √(s)=41.6 GeV with the Hera-B detector located at DESY, Hamburg (Germany), and the design of silicon microstrip sensors for the LHCb experiment at CERN, Geneva (Switzerland). Λ, Ξ and Ω hyperons and their antiparticles were reconstructed from 113.5 . 106 inelastic collisions of protons with fixed carbon, titanium and tungsten targets. With these samples, antiparticle-to-particle ratios, cross sections integrated for the accessible kinematic region of Hera-B and single differential cross sections as function of transverse momentum, dσ/dpT2 (for Λ and Ξ) and rapidity, dσ/dy (for Λ only), have been been measured as well as the dependence of these quantities on the atomic number of the target nucleus, as parameterized using the Glauber model. The obtained ratios follow the same trend as found for the energy dependence of measurements from nucleus-nucleus collisions. Silicon microstrip sensors have been designed for the tracking system of the LHCb detector. Evaluating the performance in beam tests at CERN, the strip geometry and sensor thickness were varied optimizing for a large signal-to-noise ratio, a small number of read-out channels and a low occupancy. The detector is currently being built to be operational for first proton-proton collisions in autumn 2007. (orig.)

  6. Hyperon production in proton-nucleus collisions at a center-of-mass energy of {radical}(s{sub NN}) = 41.6 GeV at HERA-B and design of silicon microstrip detectors for tracking at LHCb

    Energy Technology Data Exchange (ETDEWEB)

    Agari, Michaela

    2006-07-01

    The topics of this thesis are the measurements of hyperon production in protonnucleus collisions at {radical}(s)=41.6 GeV with the Hera-B detector located at DESY, Hamburg (Germany), and the design of silicon microstrip sensors for the LHCb experiment at CERN, Geneva (Switzerland). {lambda}, {xi} and {omega} hyperons and their antiparticles were reconstructed from 113.5 . 10{sup 6} inelastic collisions of protons with fixed carbon, titanium and tungsten targets. With these samples, antiparticle-to-particle ratios, cross sections integrated for the accessible kinematic region of Hera-B and single differential cross sections as function of transverse momentum, d{sigma}/dp{sub T}{sup 2} (for {lambda} and {xi}) and rapidity, d{sigma}/dy (for {lambda} only), have been been measured as well as the dependence of these quantities on the atomic number of the target nucleus, as parameterized using the Glauber model. The obtained ratios follow the same trend as found for the energy dependence of measurements from nucleus-nucleus collisions. Silicon microstrip sensors have been designed for the tracking system of the LHCb detector. Evaluating the performance in beam tests at CERN, the strip geometry and sensor thickness were varied optimizing for a large signal-to-noise ratio, a small number of read-out channels and a low occupancy. The detector is currently being built to be operational for first proton-proton collisions in autumn 2007. (orig.)

  7. Automated mapping of burned areas in Landsat imagery; tracking spatial and temporal patterns of burned areas and greenhouse gas emissions in the Southern Rocky Mountains, USA.

    Science.gov (United States)

    Hawbaker, Todd; Vanderhoof, Melanie; French, Nancy; Billmire, Michael; Beal, Yen-Ju Grace; Takacs, Josh; Bosshart, Robbert; Caldwell, Megan

    2016-04-01

    Accurate estimates of greenhouse gas emissions depend on precise mapping of burned area extent and timing. Consequently, fire disturbance has been identified by the Global Climate Observing System (GCOS) program as one of the 14 Terrestrial Essential Climate Variables (ECVs). Landsat's temporal resolution and sensor characteristics make it more suitable for mapping burned area than existing burned area products from coarse resolution sensors. We have developed an automated algorithm to identify burned areas in temporally rich stacks of Landsat surface reflectance data using boosted regression trees and spatial filters. For this analysis, we quantified trends in burned area and fire emissions using the USGS Burned Area ECV data and the Monitoring Trends in Burn Severity data, the latter of which is known to be incomplete. Both datasets were combined with the LANDFIRE Fuel Characteristic Classification System to assign pre-fire biomass loads, and the CONSUME model was used to estimate biomass consumption and greenhouse gas emissions. Both data sets show a dramatic increase in burned area between 1984-1999 and 2000-2015, but the Burned Area ECV included more small fires and fires in non-forest ecosystems. Emission estimates were similar between the two burned area datasets, but were generally greater for the Burned Area ECV. Our results suggest that national and regional scale emission estimates could be improved by incorporating the more complete Burned Area ECV dataset.

  8. Slab track

    OpenAIRE

    Golob, Tina

    2014-01-01

    The last 160 years has been mostly used conventional track with ballasted bed, sleepers and steel rail. Ensuring the high speed rail traffic, increasing railway track capacities, providing comfortable and safe ride as well as high reliability and availability railway track, has led to development of innovative systems for railway track. The so-called slab track was first built in 1972 and since then, they have developed many different slab track systems around the world. Slab track was also b...

  9. Porous silicon gettering

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Menna, P.; Al-Jassim, M. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-08-01

    We have studied a novel extrinsic gettering method that utilizes the very large surface areas, produced by porous silicon etch on both front and back surfaces of the silicon wafer, as gettering sites. In this method, a simple and low-cost chemical etching is used to generate the porous silicon layers. Then, a high-flux solar furnace (HFSF) is used to provide high-temperature annealing and the required injection of silicon interstitials. The gettering sites, along with the gettered impurities, can be easily removed at the end the process. The porous silicon removal process consists of oxidizing the porous silicon near the end the gettering process followed by sample immersion in HF acid. Each porous silicon gettering process removes up to about 10 {mu}m of wafer thickness. This gettering process can be repeated so that the desired purity level is obtained.

  10. Continuous Czochralski growth: silicon sheet growth development of Large Area Silicon Sheet Task of the Low-Cost Silicon Solar Array Project. Second quarterly progress report, January 1--March 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This project is directed toward the development of equipment and processes to produce single crystal solar silicon by a continuous Czochralski (CZ) method. ''Continuous'' is defined as the production of at least 100 kilograms of crystal from a single melt container. The approach to be taken is to suitably modify a Hamco CG2000 crystal grower to demonstrate that continuous CZ growth is feasible by the periodic replenishment of the melt container and the removal of grown crystals. The crystal growth facility is now complete with the exception of the poly weight/recharge system. Installation of this device on the grower will require disassembly of the facility to modify the growth chambers. In the meantime, hot filling experiments are being conducted by attaching poly rod material to the seed lift mechanism. The work has progressed to the point where a suitable means of melt replenishment has been demonstrated. A poly-crystalline rod of silicon can be lowered into the crucible and melted at rates of over 14 kg/hr. Using this method of hot filling, a 12'' x 9'' high crucible was charged with 25 kg of silicon and a zero dislocation, 22 kg crystal 11.4 cm diameter, 87 cm long, was grown. This demonstrates that five crystals grown from a 12 inch crucible can satisfy the continuous CZ criterion. A growth rate of 7.3 cm/hr was achieved corresponding to a continuous throughput of 1.1 kg/hr. An economic model using the SAMICS/IPEG guidelines has shown that the add-on cost of CZ crystal growth can meet the 1982 goals without any technical breakthroughs, but an add-on cost reduction of approximately 50% is necessary to meet the 1986 goal, assuming reasonable slicing yields.

  11. Silicon microphones - a Danish perspective

    DEFF Research Database (Denmark)

    Bouwstra, Siebe; Storgaard-Larsen, Torben; Scheeper, Patrick;

    1998-01-01

    Two application areas of microphones are discussed, those for precision measurement and those for hearing instruments. Silicon microphones are under investigation for both areas, and Danish industry plays a key role in both. The opportunities of silicon, as well as the challenges and expectations......, are discussed. For precision measurement the challenge for silicon is large, while for hearing instruments silicon seems to be very promising....

  12. Quantitative analysis of defects in silicon: silicon sheet growth development for the Large Area Silicon Sheet Task of the Low-Cost Solar Array Project. Quarterly progress report No. 5, April 1-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Natesh, R.; Smith, J.M.; Qidwai, H.A.; Bruce, T.

    1979-07-12

    During this reporting period a computer program was written for the PDP 11/03 computer that controls the Quantimet 720 Image Analyzing System (QTM 720). This program will facilitate the analysis of silicon samples on the upgraded Quantimet 720 System. Also during this period thirty-two (32) Motorola samples were analyzed for twin boundaries, dislocation pits, and grain boundaries. A discussion of the computer program and the data obtained from the thirty-two (32) Motorola samples are given. The use of the Image Editor on the QTM 720 detected image is also described.

  13. 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.

  14. A silicon detector for neutrino physics

    CERN Document Server

    Kokkonen, J

    2002-01-01

    In order to demonstrate the feasibility of conducting future muon neutrino - tau neutrino oscillation searches using a high-resolution, large-area silicon microstrip detector, the Silicon TARget (STAR) detector was built. STAR was installed in the NOMAD short baseline neutrino oscillation experiment at the CERN SPS neutrino beam, where it recorded approximately 10000 neutrino interactions during the operation of the detector in the period 1997-98. It consists of five layers of silicon detectors interleaved with four layers of passive boron carbide as the target. The target mass is 45 kg, while the total silicon surface area is 1.14 square-meters and contains 32000 readout channels. The individual modules have a length of 72 cm, the longest built to date. The detection of tau particles, produced in tau neutrino charged-current interactions, would require a tracking detector with a precision of a few tens of microns in order to measure the position of the neutrino interaction vertex as well as the impact parame...

  15. Results of Tritium Tracking and Groundwater Monitoring at the Hanford Site 200 Area State-Approved Land Disposal Site-FY 1999

    International Nuclear Information System (INIS)

    The Hanford Site 200 Area Effluent Treatment Facility (ETF) processes contaminated liquids derived from Hanford Site facilities. The clean water generated by these processes is occasionally enriched in tritium and is discharged to the 200 Area State Approved Land Disposal Site (SALDS). Groundwater monitoring for tritium and other constituents is required by the state-issued permit at 21 wells surrounding the facility. During FY 1999, average tritium activities in most wells declined from average activities in 1998. The exception was deep well 69948-77C, where tritium results were at an all-time high (77,000 pCi/L) as a result of the delayed penetration of effluent deeper into the aquifer. Of the 12 constituents with permit enforcement limits, which are monitored in SALDS proximal wells, all were within limits during FY 1999. Water level measurements in nearby wells indicate that a small hydraulic mound exists around the SALDS facility as a result of discharges. This feature is directing groundwater flow radially outward a short distance before the regional northeasterly flow predominates. Evaluation of this condition indicates that the network is currently adequate for tracking potential effects of the SALDS on the groundwater. Recommendations include the discontinuation of ammonia, benzene, tetrahydrofuran, and acetone from the regular groundwater constituent list; designating background well 299-W8-1 as a tritium-tracking well only, and the use of quadruplicate averages of field pH, instead of a single laboratory measurement, as a permit compliance parameter

  16. Development and operation of a novel PC-based high speed beam telescope for particle tracking using double sided silicon microstrip detectors

    International Nuclear Information System (INIS)

    A PC based high speed silicon microstrip beam telescope consisting of several independent modules is presented. Every module contains an AC-coupled double sided silicon microstrip sensor and a complete set of analog and digital signal processing electronics. A digital bus connects the modules with the DAQ PC. A trigger logic unit coordinates the operation of all modules of the telescope. The system architecture allows easy integration of any kind of device under test into the data acquisition chain. Signal digitization, pedestal correction, hit detection and zero suppression are done by hardware inside the modules, so that the amount of data per event is reduced by a factor of 80 compared to conventional readout systems. In combination with a two level data acquisition scheme, this allows event rates up to 7.6 kHz. This is a factor of 40 faster than conventional VME based beam telescopes while comparable analog performance is maintained achieving signal to noise ratios of up to 70:1. The telescope has been tested in the SPS testbeam at CERN. It has been adopted as the reference instrument for testbeam studies for the ATLAS pixel detector development. (orig.)

  17. The LHCb Silicon Tracker

    CERN Document Server

    Bernhard, R P; Bauer, J; Blouw, J; Hofmann, W; Löchner, S; Maciuc, F; Schmelling, M; Smale, N; Schwingenheuer, B; Voss, H; Borysova, M; Ohrimenko, O; Pugatch, V; Yakovenko, V; Bay, A; Bettler, M O; Fauland, P; Frei, R; Nicolas, L; Knecht, M; Perrin, A; Schneider, O; Tran, M T; Van Hunen, J; Vervink, K; Adeva, B; Esperante-Pereira, D; Gallas, A; Fungueirino-Pazos, J L; Lois, C; Pazos-Alvarez, A; Pérez-Trigo, E; Pló-Casasus, M; Vázquez, P; Bernet, R; Gassner, J; Lehner, F; Sakhelashvili, T; Steiner, S; Steinkamp, O; Straumann, U; Van Tilburg, J; Vollhardt, A; Volyanskyy, D; Wenger, A

    2007-01-01

    The Silicon Tracker is a large-surface silicon micro-strip detector that covers the full acceptance of the experiment in a single tracking station upstream of the spectrometer magnet and the inner-most part of the three tracking stations downstream of the magnet. Special emphasis has been put on module quality assurance at all stages of the production. Various tests are performed after each production step and each module goes through several burn-in cycles. The design of the LHCb silicon detectors is described and the main lessons learnt from the R&D phase are summarized. Focus will be on the experience from module production and the quality assurance program.

  18. INNER TRACKING

    CERN Multimedia

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The successful commissioning of ~ 25% of the Silicon Strip Tracker was completed in the Tracker Integration Facility (TIF) at CERN on 18 July 2007 and the Tracker has since been prepared for moving and installation into CMS at P5. The Tracker will be ready to move on schedule in September 2007. The Installation of the Tracker cooling pipes and LV cables between Patch Panel 1 (PP1) on the inside the CMS magnet cryostat, and the cooling plants and power system racks on the balconies has been completed. The optical fibres from PP1 to the readout FEDs in the USC will be installed in parallel with the installation of the EB/HB services, and will be completed in October. It is planned to install the Tracker into CMS at the end of October, after the completion of the installation of the EB/HB services. The Tracker will then be connected to the pre-installed services on YB0 and commissioned with CMS in December. The FPix and BPix continue to make ...

  19. INNER TRACKING

    CERN Multimedia

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The successful commissioning of ~ 25% of the Silicon Strip Tracker was completed in the Tracker Integration Facility (TIF) at CERN in July 2007 and the Tracker has since been prepared for moving and installation into CMS at P5. The Tracker was ready to move on schedule in September 2007. The Installation of the Tracker cooling pipes and LV cables between Patch Panel 1 (PP1) on the inside the CMS magnet cryostat, and the cooling plants and power system racks on the balconies has been completed. The optical fibres from PP1 to the readout FEDs in the USC have been installed, together with the Tracker cable channels, in parallel with the installation of the EB/HB services. All of the Tracker Safety, Power, DCS and the VME Readout Systems have been installed at P5 and are being tested and commissioned with CMS. It is planned to install the Tracker into CMS before Christmas. The Tracker will then be connected to the pre-installed services on Y...

  20. Continuous bottom temperature measurements in strategic areas of the Florida Reef Track at Tennessee Reef, 1990 - 2004 (NODC Accession 0002749)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to document bottom seawater temperature in strategic areas of the Florida Reef Tract on a continuing basis and make that information...

  1. Characteristics of the ALICE Silicon Drift Detector

    International Nuclear Information System (INIS)

    A Silicon Drift Detector (SDD) with an active area of 7.0x7.5 cm2 has been designed, produced and tested for the ALICE Inner Tracking System. The development of the SDD has been focused on the capability of the detector to work without an external support to the integrated high-voltage divider. Several features have been implemented in the design in order to increase the robustness and the long-term electrical stability of the detector. One of the prototypes has been tested in a pion beam at the CERN SPS. Preliminary results on the position resolution are given

  2. Detection of Vehicle Tracks and Vegetation Damages Caused by use of Snowmobiles in the Longyearbyen Area on Svalbard using Unmanned Aircraft

    Science.gov (United States)

    Storvold, R.; Karlsen, S. R.; Solbø, S. A.; Johansen, B.; Johansen, K.; Høgda, K. A.; Tømmervik, H.; Zmarz, A.; Joly, D.

    2013-12-01

    The study area in the surroundings of Longyearbyen on Svalbard, Arctic Norway, located at 71.2°N and 16°E is characterized by dry Arctic climate with a snow season of more than eight months, annual precipitation of less than 200mm, and a mean July temperature of about 6°C. Longyearbyen is the main settlement on Svalbard, with about 2000 inhabitants. During the last two decades the number of snowmobiles have increased from a few hundred to a number almost equals the number of inhabitants, and snowmobile trips are today the one of the main leisure activities. In addition, thousands of tourist visits every spring, and many of these go on organized snowmobile trips. Due to the often thin snow cover, and use of snowmobile even during the spring snow melt in May and early June, the rapid growth in use of snowmobile has made some damage to the vegetation. Damage on the fragile vegetation caused by the skids and belts of the snowmobile can be observed in most parts of the Adventdalen valley, close to Longyearbyen. The main aim of this study is to explore the feasibility and accuracy of using data from Unmanned Aircraft Systems (UAS) to identify vehicle tracks and damages on vegetation caused by the use of snowmobiles. Use of UAS give the opportunity to carry out research in a manner that minimizes the environmental footprint of the research activities. Small unmanned aircraft, combining both fixed wing multi rotor types allow us to collect image data for vegetation mapping without having any personnel walking into the field disturbing the sensitive High Arctic ecosystems. UAS used here are inexpensive and simple to operate. They are being developed with the goal of providing airborne capabilities for scientists at an affordable cost. The aircraft were instrumented with a normal Canon Powershot S100 RGB compact camera and a modified Canon Powershot SX230 NDVI camera. The fixed wing aircraft was taking pictures from 100 meters altitude with ground resolution of 2.5 cm

  3. Tracking historical lead pollution in the coastal area adjacent to the Yangtze River Estuary using lead isotopic compositions

    International Nuclear Information System (INIS)

    The rapid economic development in the Yangtze River Delta (YRD), China in the last three decades has had a significant impact on the environment of the East China Sea (ECS). Lead isotopic compositions of a 210Pb dated sediment core collected from the coastal ECS adjacent to the Yangtze River Estuary were analyzed to track the Pb pollution in the region. The baseline Pb concentration in the coastal ECS sediments before the industrialization in China was 32 μg g-1, and the corresponding 206Pb/207Pb ratio was 1.195. The high-resolution profiles of Pb flux and 206Pb/207Pb ratios had close relationships with the economic development and the history of the use of leaded gasoline in China, and they were clearly different from those of most European countries and United States. - The combination of Pb concentration, sedimentary flux, Pb isotopic composition and 210Pb dating in the coastal ECS sediments revealed the historical Pb pollution in China

  4. Silicone metalization

    Science.gov (United States)

    Maghribi, Mariam N.; Krulevitch, Peter; Hamilton, Julie

    2008-12-09

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  5. Silicone metalization

    Science.gov (United States)

    Maghribi, Mariam N.; Krulevitch, Peter; Hamilton, Julie

    2006-12-05

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  6. Precision fabrication of large area silicon-based geometrically enhanced x-ray photocathodes using plasma etching

    Science.gov (United States)

    Opachich, Y. P.; Chen, N.; Bell, P. M.; Bradley, D. K.; Feng, J.; Gopal, A.; Hilsabeck, T. J.; Huffman, E.; Koch, J. A.; Landen, O. L.; MacPhee, A. G.; Nagel, S. R.; Udin, S.

    2015-08-01

    Geometrically enhanced photocathodes are currently being developed for use in applications that seek to improve detector efficiency in the visible to X-ray ranges. Various photocathode surface geometries are typically chosen based on the detector operational wavelength region, along with requirements such as spatial resolution, temporal resolution and dynamic range. Recently, a structure has been identified for possible use in the X-ray region. This anisotropic high aspect ratio structure has been produced in silicon using inductively coupled plasma (ICP) etching technology. The process is specifically developed with respect to the pattern density and geometry of the photocathode chip to achieve the desired sidewall profile angle. The tapered sidewall profile angle precision has been demonstrated to be within +/- 2.5° for a ~ 12° wall angle, with feature sizes that range between 4-9 μm in diameter and 10-25 μm depth. Here we discuss the device applications, design and present the method used to produce a set of geometrically enhanced high yield X-ray photocathodes in silicon.

  7. 3D silicon sensors: Design, large area production and quality assurance for the ATLAS IBL pixel detector upgrade

    International Nuclear Information System (INIS)

    3D silicon sensors, where electrodes penetrate the silicon substrate fully or partially, have successfully been fabricated in different processing facilities in Europe and USA. The key to 3D fabrication is the use of plasma micro-machining to etch narrow deep vertical openings allowing dopants to be diffused in and form electrodes of pin junctions. Similar openings can be used at the sensor's edge to reduce the perimeter's dead volume to as low as ∼4 μm. Since 2009 four industrial partners of the 3D ATLAS R and D Collaboration started a joint effort aimed at one common design and compatible processing strategy for the production of 3D sensors for the LHC Upgrade and in particular for the ATLAS pixel Insertable B-Layer (IBL). In this project, aimed for installation in 2013, a new layer will be inserted as close as 3.4 cm from the proton beams inside the existing pixel layers of the ATLAS experiment. The detector proximity to the interaction point will therefore require new radiation hard technologies for both sensors and front end electronics. The latter, called FE-I4, is processed at IBM and is the biggest front end of this kind ever designed with a surface of ∼4 cm2. The performance of 3D devices from several wafers was evaluated before and after bump-bonding. Key design aspects, device fabrication plans and quality assurance tests during the 3D sensors prototyping phase are discussed in this paper.

  8. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Directory of Open Access Journals (Sweden)

    J. P. Lapidez

    2015-07-01

    Full Text Available Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH which is the flagship disaster mitigation program of the Department of Science and Technology (DOST of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948–2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  9. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Directory of Open Access Journals (Sweden)

    J. P. Lapidez

    2015-02-01

    Full Text Available Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH, the flagship disaster mitigation program of the Department of Science and Technology (DOST, Government of the Philippines, to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948–2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  10. Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

    Science.gov (United States)

    Lapidez, J. P.; Tablazon, J.; Dasallas, L.; Gonzalo, L. A.; Cabacaba, K. M.; Ramos, M. M. A.; Suarez, J. K.; Santiago, J.; Lagmay, A. M. F.; Malano, V.

    2015-07-01

    Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR) on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH) which is the flagship disaster mitigation program of the Department of Science and Technology (DOST) of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948-2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

  11. Study of radon exhalation rates using solid state nuclear track detectors in stone mining area of Aravali range in Pali region, district Faridabad

    International Nuclear Information System (INIS)

    It is well established that indoor radon-thoron and daughters are the largest contributor to total radiation dose received by populations. They account for more than 50% of the total dose and the radiation exposure beyond permissible levels can lead to deleterious effects on health. This fact necessitates extensive studies of natural radioactivity levels in the stone mining area of Aravali range in Faridabad. The stone mining area of Aravali Range in Pali, District Faridabad bears significant geological features. Radon exhalation from ground plays an important role in enhanced indoor radon levels and can pose grave health hazards to the workers and the residents. Exhalation rates (mass and surface) from stone samples of the area have been studied using LR-115, Type II nuclear track detectors. The mass and surface exhalation rates from crushed stone samples, also called stone dust varied in the range 3.41-9.11 mBq kg-1 h-1 and 75.9-202.7 mBq m-2 h-1, respectively. The study has revealed substantial presence of radionuclides in the samples collected from the mining area. (author)

  12. Satellite tracking of harbour seals on Horns Reef - Use of the Horns Reef wind farm area and the North Sea

    International Nuclear Information System (INIS)

    Ten harbour seals (Phoca vitulina) caught on the Danish Wadden Sea island Roemoe were equipped with satellite linked time depth recorders. The animals were caught on three separate occasions (Jan. 4th, Feb. 18th and May 6th, 2002). The transmitters worked between 49 and 100 days, relaying positional and dive information back via the ARGOS satellite service until beginning of July. Background for the studies is the construction of the Worlds largest off shore wind farm on Horns Reef. Based on previous studies using VHF-transmitters, it was expected that the seals would spend considerable time on Horns Reef. The VHF-telemetry studies showed that the preferred direction for seals leaving the Danish Wadden Sea is NW from Graedyb tidal area outside Esbjerg, the direction directly towards the wind farm area. The previously used VHF-transmitters had a limited detection range and it was decided to equip a number of seals from the same area as before with satellite transmitters. This allows for positioning of the seals in the entire North Sea as well as providing dive summary information, as a transmitter with a depth transducer was chosen for the study. Positional information revealed that animals move about more extensively than previously believed. Substantial variation between animals was observed and each seal seemed to have adopted its own foraging strategy. Some animals travelled to the centre of the North Sea on foraging trips and spent considerable time close to the bottom at 30-70 meters depth. Other seals remained in the German Bight and yet others spent considerable time on and around Horns Reef. The area of Horns reef wind farm constitutes a negligible fraction of the total area visited by the tagged seals. The reef as a whole however, appears to be important to the seals both for foraging and as transit area to other feeding grounds further off shore. The resolution in positional information is not sufficiently high to allow for a detailed study of the effects

  13. Satellite tracking of harbour seals on Horns Reef - Use of the Horns Reef wind farm area and the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Tougaard, J.; Tougaard, S.; Jensen, Thyge [Fisheries and Maritime Museum Esbjerg (Denmark); Ebbesen, I. [Univ. of Sourthern Denmark, Inst. of Biology, Odense (Denmark); Teilmann, J. [NationL Environmental Res. Inst., Roskidle (Denmark)

    2003-03-15

    Ten harbour seals (Phoca vitulina) caught on the Danish Wadden Sea island Roemoe were equipped with satellite linked time depth recorders. The animals were caught on three separate occasions (Jan. 4th, Feb. 18th and May 6th, 2002). The transmitters worked between 49 and 100 days, relaying positional and dive information back via the ARGOS satellite service until beginning of July. Background for the studies is the construction of the Worlds largest off shore wind farm on Horns Reef. Based on previous studies using VHF-transmitters, it was expected that the seals would spend considerable time on Horns Reef. The VHF-telemetry studies showed that the preferred direction for seals leaving the Danish Wadden Sea is NW from Graedyb tidal area outside Esbjerg, the direction directly towards the wind farm area. The previously used VHF-transmitters had a limited detection range and it was decided to equip a number of seals from the same area as before with satellite transmitters. This allows for positioning of the seals in the entire North Sea as well as providing dive summary information, as a transmitter with a depth transducer was chosen for the study. Positional information revealed that animals move about more extensively than previously believed. Substantial variation between animals was observed and each seal seemed to have adopted its own foraging strategy. Some animals travelled to the centre of the North Sea on foraging trips and spent considerable time close to the bottom at 30-70 meters depth. Other seals remained in the German Bight and yet others spent considerable time on and around Horns Reef. The area of Horns reef wind farm constitutes a negligible fraction of the total area visited by the tagged seals. The reef as a whole however, appears to be important to the seals both for foraging and as transit area to other feeding grounds further off shore. The resolution in positional information is not sufficiently high to allow for a detailed study of the effects

  14. Is the Region of Visegrad Countries on the Track to the Euro Area? Recent Evidence from the Real Convergence Perspective

    Directory of Open Access Journals (Sweden)

    Daniel Stavárek

    2014-09-01

    Full Text Available After enlargement of the European Union and subsequently joining of a new member states to the euro area, the question of economic convergence attracted considerable research interest. This paper adopts three alternative concepts to examine the level and trend of convergence in the Visegrad countries (Czech Republic, Hungary, Poland, Slovakia. We concurrently estimate the β-convergence, σ-convergence and business cycle synchronization to find out whether all countries are on the way towards higher convergence with the euro area. The results suggest that convergence of all countries has been increasing. However, the recent acceleration of the convergence process is caused mainly by external shocks in the form of the financial crisis and following economic slowdowns. Hence, the current level of convergence in the Visegrad countries cannot be considered as fully adequate.

  15. Large area multicrystalline silicon solar cells with high efficiency. Final report; Grossflaechige multikristalline Silizium-Solarzellen mit hohen Wirkungsraden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Ebest, G.; Erler, K.; Mrwa, A.; Ball, M.

    2001-09-01

    Solar cells were produced of wafers of die-cast and strip-drawn multicrystalline silicon and characterized. Production methods like SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) and screen printing were investigated. The results are summarized as follows: 1. Layer resistance can be adjusted by variation of the RTP temperature cycle and by selecting appropriate doping materials (P507 by Filmtronics); 2. The low resistance required for screen printing metallization are obtained only with a different doping material (P8545SF-Filmtronics); 3. Metallized aluminium and copper require a 30 nm TiN layer as diffusion barrier; 4. Reflectivity will be reduced most effectively by RIE with chlorine gas on monocrystalline and multicrystalline silicon wafers. [German] Im Rahmen des Projektes wurden auf Wafern aus blockgegossenem und bandgezogenem multikristallinen Silizium Solarzellen hergestellt und charakterisiert. Fuer die Herstellung wurden Verfahren wie SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) und Siebdruck untersucht. Die Ergebnisse lassen sich wie folgt zusammenfassen: 1. eine Einstellung des Schichtwiderstandes wird durch Variation des RTP-Temperaturzyklus sowie Auswahl verschiedener Dotierstoffe (P507 von Filmtronics) erreicht; 2. die fuer die Siebdruckmetallisierung erforderlichen geringen Schichtwiderstaende werden nur durch die Wahl eines anderen Dotierstoffes (P8545SF-Filmtronics) erreicht; 3. Aluminium- und Kupfermetallisierungen benoetigen eine 30 nm dicke TiN-Schicht als Diffusionsbarriere; und 4. die wirksamste Verminderung des Reflexionsgrades ist mittels RIE-Verfahren unter Verwendung von Chlorgas auf ein- und multikristalline Siliziumwafer erreichbar.

  16. Performance of ultra-small silicon photomultiplier array with active area of 0.12 mm×0.12 mm

    International Nuclear Information System (INIS)

    We report the performance of an ultra-small silicon photomultiplier (SiPM) line array with 7 elements of 0.12×0.12 mm2 in active area, 0.2 mm in pitch and 120 micro cells in one element. The device features an epitaxial bulk quenching resistor concept, demonstrated high geometrical fill factor of 41% and photon detection efficiency (PDE) of 25.4% in the wavelength region between 430 nm and 480 nm while retaining high micro cell density around 10 000 mm−2 and ~3 ns FWHM of dark pulses width; it also demonstrated dark count rate of less than 28.7 kHz, optical crosstalk of the order of 2% to 4%, and excellent photon number discrimination. A 0.15 mm×1.6 mm×1.6 mm lutetium yttrium oxyorthosilicate (LYSO) crystal, corresponding to the width, length and height respectively, was successfully coupled to the 1×7 SiPM array for possible ultra-highly resolved positron emission tomography (PET) applications. This novel type of device has advantages particularly for small active area since the performances, such as PDE and response speed is one of the best among SiPMs with similarly high density of micro cells. It may pave a way for this type of SiPM as a promising pixel position sensitive device in imaging sensor applications. - Highlights: • The ultra-small SiPM line array with active area of 0.12 mm×0.12 mm was presented. • The ultra-small SiPM employs the bulk silicon structure as quenching resistor. • A considerable dynamic range and PDE over 25.4% @ 430 nm to 480 nm were characterized

  17. Performance of ultra-small silicon photomultiplier array with active area of 0.12 mm×0.12 mm

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Wang; Zongde, Chen; Chenhui, Li; Ran, He; Shenyuan, Wang; Baicheng, Li; Ruiheng, Wang; Kun, Liang, E-mail: lk@bnu.edu.cn; Ru, Yang; Dejun, Han

    2015-07-01

    We report the performance of an ultra-small silicon photomultiplier (SiPM) line array with 7 elements of 0.12×0.12 mm{sup 2} in active area, 0.2 mm in pitch and 120 micro cells in one element. The device features an epitaxial bulk quenching resistor concept, demonstrated high geometrical fill factor of 41% and photon detection efficiency (PDE) of 25.4% in the wavelength region between 430 nm and 480 nm while retaining high micro cell density around 10 000 mm{sup −2} and ~3 ns FWHM of dark pulses width; it also demonstrated dark count rate of less than 28.7 kHz, optical crosstalk of the order of 2% to 4%, and excellent photon number discrimination. A 0.15 mm×1.6 mm×1.6 mm lutetium yttrium oxyorthosilicate (LYSO) crystal, corresponding to the width, length and height respectively, was successfully coupled to the 1×7 SiPM array for possible ultra-highly resolved positron emission tomography (PET) applications. This novel type of device has advantages particularly for small active area since the performances, such as PDE and response speed is one of the best among SiPMs with similarly high density of micro cells. It may pave a way for this type of SiPM as a promising pixel position sensitive device in imaging sensor applications. - Highlights: • The ultra-small SiPM line array with active area of 0.12 mm×0.12 mm was presented. • The ultra-small SiPM employs the bulk silicon structure as quenching resistor. • A considerable dynamic range and PDE over 25.4% @ 430 nm to 480 nm were characterized.

  18. Radon measurements by nuclear track detectors in dwellings in Oke-Ogun area, South-western (Nigeria)

    International Nuclear Information System (INIS)

    An indoor radon survey of a total of 77 dwellings randomly selected in 10 districts in Oke-Ogun area of Oyo state, South-western Nigeria was carried out using CR-39 detectors. The CR-39 detectors were placed in the bedrooms and living rooms and exposed for 6 months and then etched in NaOH 6.25 N solution at 90 deg. C for 3 h. Mean concentrations amount to 255±47 and 259±67 Bq m-3 in the living rooms and bedrooms, respectively. The lowest radon concentration (77±29 Bq m-3) was found in Igbeti, whereas the highest was found in Okeho (627±125 Bq m-3). The annual exposure of dwellers was estimated to fall -1 n living rooms and bedrooms, respectively), which is the upper range of action levels recommended by the International Commission on Radiological Protection. The average excess lung cancer risk was estimated 24.8 and 25.2 per million person-years in both living rooms and bedrooms. It is believed that the high radon level in this part of the country may be attributed to its geographic location. The data presented here will serve as a baseline survey for radon concentration in dwellings in the area. (authors)

  19. Closure Report for Corrective Action Unit 539: Areas 25 and 26 Railroad Tracks Nevada National Security Site, Nevada with ROTC-1, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Kauss

    2011-06-01

    This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 539: Areas 25 and 26 Railroad Tracks, Nevada National Security Site, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. The corrective action sites (CASs) within CAU 539 are located within Areas 25 and 26 of the Nevada National Security Site. Corrective Action Unit 539 comprises the following CASs: • 25-99-21, Area 25 Railroad Tracks • 26-99-05, Area 26 Railroad Tracks The purpose of this CR is to provide documentation supporting the completed corrective actions and provide data confirming that the closure objectives for CASs within CAU 539 were met. To achieve this, the following actions were performed: • Reviewed documentation on historical and current site conditions, including the concentration and extent of contamination. • Conducted radiological walkover surveys of railroad tracks in both Areas 25 and 26. • Collected ballast and soil samples and calculated internal dose estimates for radiological releases. • Collected in situ thermoluminescent dosimeter measurements and calculated external dose estimates for radiological releases. • Removed lead bricks as potential source material (PSM) and collected verification samples. • Implemented corrective actions as necessary to protect human health and the environment. • Properly disposed of corrective action and investigation wastes. • Implemented an FFACO use restriction (UR) for radiological contamination at CAS 25-99-21. The approved UR form and map are provided in Appendix F and will be filed in the DOE, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), Facility Information Management System; the FFACO database; and the NNSA/NSO CAU/CAS files. From November 29

  20. Integration of kerma-area product and cumulative air kerma determination into a skin dose tracking system for fluoroscopic imaging procedures

    Science.gov (United States)

    Vijayan, Sarath; Shankar, Alok; Rudin, Stephen; Bednarek, Daniel R.

    2016-03-01

    The skin dose tracking system (DTS) that we developed provides a color-coded mapping of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures in real time. The DTS has now been modified to also calculate the kerma area product (KAP) and cumulative air kerma (CAK) for fluoroscopic interventions using data obtained in real-time from the digital bus on a Toshiba Infinix system. KAP is the integral of air kerma over the beam area and is typically measured with a large-area transmission ionization chamber incorporated into the collimator assembly. In this software, KAP is automatically determined for each x-ray pulse as the product of the air kerma/ mAs from a calibration file for the given kVp and beam filtration times the mAs per pulse times the length and width of the beam times a field nonuniformity correction factor. Field nonuniformity is primarily the result of the heel effect and the correction factor was determined from the beam profile measured using radio-chromic film. Dividing the KAP by the beam area at the interventional reference point provides the area averaged CAK. The KAP and CAK per x-ray pulse are summed after each pulse to obtain the total procedure values in real-time. The calculated KAP and CAK were compared to the values displayed by the fluoroscopy machine with excellent agreement. The DTS now is able to automatically calculate both KAP and CAK without the need for measurement by an add-on transmission ionization chamber.

  1. Neonate turtle tracking data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of this project are to use novel satellite tracking methods to provide improved estimation of threats at foraging areas and along migration routes...

  2. LHCb Silicon Tracker infrastructure

    CERN Document Server

    Ermoline, Yuri

    2004-01-01

    The LHCb Silicon Tracker is a vital part of the experiment. It consists of four planar stations: one trigger and three inner tracking stations. The operation of the Silicon Tracker detectors and electronics is provided by its infrastructure: cooling system, high- and low-voltage power supply systems, temperature and radiation monitoring systems. Several components of these systems are located in the experimental hall and subjected to radiation. This paper mainly concentrates on the recent development: requirements definition, evaluation of possible implementation scenarios, component choice and component radiation tests.

  3. Evaluating Crop Area Mapping from MODIS Time-Series as an Assessment Tool for Zimbabwe's "Fast Track Land Reform Programme".

    Science.gov (United States)

    Hentze, Konrad; Thonfeld, Frank; Menz, Gunter

    2016-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) data forms the basis for numerous land use and land cover (LULC) mapping and analysis frameworks at regional scale. Compared to other satellite sensors, the spatial, temporal and spectral specifications of MODIS are considered as highly suitable for LULC classifications which support many different aspects of social, environmental and developmental research. The LULC mapping of this study was carried out in the context of the development of an evaluation approach for Zimbabwe's land reform program. Within the discourse about the success of this program, a lack of spatially explicit methods to produce objective data, such as on the extent of agricultural area, is apparent. We therefore assessed the suitability of moderate spatial and high temporal resolution imagery and phenological parameters to retrieve regional figures about the extent of cropland area in former freehold tenure in a series of 13 years from 2001-2013. Time-series data was processed with TIMESAT and was stratified according to agro-ecological potential zoning of Zimbabwe. Random Forest (RF) classifications were used to produce annual binary crop/non crop maps which were evaluated with high spatial resolution data from other satellite sensors. We assessed the cropland products in former freehold tenure in terms of classification accuracy, inter-annual comparability and heterogeneity. Although general LULC patterns were depicted in classification results and an overall accuracy of over 80% was achieved, user accuracies for rainfed agriculture were limited to below 65%. We conclude that phenological analysis has to be treated with caution when rainfed agriculture and grassland in semi-humid tropical regions have to be separated based on MODIS spectral data and phenological parameters. Because classification results significantly underestimate redistributed commercial farmland in Zimbabwe, we argue that the method cannot be used to produce spatial

  4. Groundwater Monitoring and Tritium-Tracking Plan for the 200 Area State-Approved Land Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, D. Brent

    2000-08-31

    The 200 Area State-Approved Land Disposal Site (SALDS) is a drainfield which receives treated wastewater, occasionally containing high levels of tritium from treatment of Hanford Site liquid wastes. Only the SALDS proximal wells (699-48-77A, 699-48-77C, and 699-48-77D) have been affected by tritium from the facility thus far; the highest activity observed (2.1E+6 pCi/L) occurred in well 699-48-77D in February 1998. Analytical results of groundwater geochemistry since groundwater monitoring began at the SALDS indicate that all constituents with permit enforcement limits have been below those limits with the exception of one measurement of total dissolved solids (TDS) in 1996. The revised groundwater monitoring sampling and analysis plan eliminates chloroform, acetone, tetrahydrofuran, benzene, and ammonia as constituents. Replicate field measurements will replace laboratory measurements of pH for compliance purposes. A deep companion well to well 699-51-75 will be monitored for tritium deeper in the uppermost aquifer.

  5. Musculoskeletal disorders in construction: A review and a novel system for activity tracking with body area network.

    Science.gov (United States)

    Valero, Enrique; Sivanathan, Aparajithan; Bosché, Frédéric; Abdel-Wahab, Mohamed

    2016-05-01

    Human body motions have been analysed for decades with a view on enhancing occupational well-being and performance of workers. On-going progresses in miniaturised wearable sensors are set to revolutionise biomechanical analysis by providing accurate and real-time quantitative motion data. The construction industry has a poor record of occupational health, in particular with regard to work-related musculoskeletal disorders (WMSDs). In this article, we therefore focus on the study of human body motions that could cause WMSDs in construction-related activities. We first present an in-depth review of existing assessment frameworks used in practice for the evaluation of human body motion. Subsequently different methods for measuring working postures and motions are reviewed and compared, pointing out the technological developments, limitations and gaps; Inertial Measurement Units (IMUs) are particularly investigated. Finally, we introduce a new system to detect and characterise unsafe postures of construction workers based on the measurement of motion data from wearable wireless IMUs integrated in a body area network. The potential of this system is demonstrated through experiments conducts in a laboratory as well as in a college with actual construction trade trainees. PMID:26851471

  6. Fish with chips: tracking reef fish movements to evaluate size and connectivity of Caribbean marine protected areas.

    Directory of Open Access Journals (Sweden)

    Simon J Pittman

    Full Text Available Coral reefs and associated fish populations have experienced rapid decline in the Caribbean region and marine protected areas (MPAs have been widely implemented to address this decline. The performance of no-take MPAs (i.e., marine reserves for protecting and rebuilding fish populations is influenced by the movement of animals within and across their boundaries. Very little is known about Caribbean reef fish movements creating a critical knowledge gap that can impede effective MPA design, performance and evaluation. Using miniature implanted acoustic transmitters and a fixed acoustic receiver array, we address three key questions: How far can reef fish move? Does connectivity exist between adjacent MPAs? Does existing MPA size match the spatial scale of reef fish movements? We show that many reef fishes are capable of traveling far greater distances and in shorter duration than was previously known. Across the Puerto Rican Shelf, more than half of our 163 tagged fish (18 species of 10 families moved distances greater than 1 km with three fish moving more than 10 km in a single day and a quarter spending time outside of MPAs. We provide direct evidence of ecological connectivity across a network of MPAs, including estimated movements of more than 40 km connecting a nearshore MPA with a shelf-edge spawning aggregation. Most tagged fish showed high fidelity to MPAs, but also spent time outside MPAs, potentially contributing to spillover. Three-quarters of our fish were capable of traveling distances that would take them beyond the protection offered by at least 40-64% of the existing eastern Caribbean MPAs. We recommend that key species movement patterns be used to inform and evaluate MPA functionality and design, particularly size and shape. A re-scaling of our perception of Caribbean reef fish mobility and habitat use is imperative, with important implications for ecology and management effectiveness.

  7. The effect of minimum impact education on visitor spatial behavior in parks and protected areas: An experimental investigation using GPS-based tracking.

    Science.gov (United States)

    Kidd, Abigail M; Monz, Christopher; D'Antonio, Ashley; Manning, Robert E; Reigner, Nathan; Goonan, Kelly A; Jacobi, Charles

    2015-10-01

    The unmanaged impacts of recreation and tourism can often result in unacceptable changes in resource conditions and quality of the visitor experience. Minimum impact visitor education programs aim to reduce the impacts of recreation by altering visitor behaviors. Specifically, education seeks to reduce impacts resulting from lack of knowledge both about the consequences of one's actions and impact-minimizing best practices. In this study, three different on-site minimum impact education strategies ("treatments") and a control condition were applied on the trails and summit area of Sargent Mountain in Acadia National Park, Maine. Treatment conditions were designed to encourage visitors to stay on marked trails and minimize off-trail travel. Treatments included a message delivered via personal contact, and both an ecological-based message and an amenity-based message posted on signs located alongside the trail. A control condition of current trail markings and directional signs was also assessed. The efficacy of the messaging was evaluated through the use of Global Positioning System (GPS) tracking of visitor spatial behavior on/off trails. Spatial analysis of GPS tracks revealed statistically significant differences among treatments, with the personal contact treatment yielding significantly less dispersion of visitors on the mountain summit. Results also indicate that the signs deployed in the study were ineffective at limiting off-trail use beyond what can be accomplished with trail markers and directional signs. These findings suggest that personal contact by a uniformed ranger or volunteer may be the most effective means of message delivery for on-site minimum impact education. PMID:26225933

  8. Fabrication, characterization and testing of silicon photomultipliers for the Muon Portal Project

    Energy Technology Data Exchange (ETDEWEB)

    La Rocca, P., E-mail: paola.larocca@ct.infn.it [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Billotta, S. [INAF - Osservatorio Astrofisico di Catania (Italy); Blancato, A.A.; Bonanno, D. [Dipartimento di Fisica e Astronomia - Catania (Italy); Bonanno, G. [INAF - Osservatorio Astrofisico di Catania (Italy); Fallica, G. [STMicroelectronics - Catania (Italy); Garozzo, S. [INAF - Osservatorio Astrofisico di Catania (Italy); Lo Presti, D. [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Marano, D. [INAF - Osservatorio Astrofisico di Catania (Italy); Pugliatti, C.; Riggi, F. [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Romeo, G. [INAF - Osservatorio Astrofisico di Catania (Italy); Santagati, G. [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Valvo, G. [STMicroelectronics - Catania (Italy)

    2015-07-01

    The Muon Portal is a recently started Project aiming at the construction of a large area tracking detector that exploits the muon tomography technique to inspect the contents of traveling cargo containers. The detection planes will be made of plastic scintillator strips with embedded wavelength-shifting fibres. Special designed silicon photomultipliers will read the scintillation light transported by the fibres along the strips and a dedicated electronics will combine signals from different strips to reduce the overall number of channels, without loss of information. Different silicon photomultiplier prototypes, both with the p-on-n and n-on-p technologies, have been produced by STMicroelectronics during the last years. In this paper we present the main characteristics of the silicon photomultipliers designed for the Muon Portal Project and describe the setup and the procedure implemented for the characterization of these devices, giving some statistical results obtained from the test of a first batch of silicon photomultipliers.

  9. Characterization of groundwater flow and transport in the General Separations Areas, Savannah River Plant: Flow model refinement and particle-tracking analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Duffield, G.M.; Buss, D.R.; Root, R.W. Jr.; Hughes, S.S.; Mercer, J.W. [GeoTrans, Inc., Sterling, VA (United States)

    1986-03-01

    The Department of Energy (DOE) is preparing the necessary NEPA documentation for an Environmental Impact Statement (EIS) to address the waste disposal activities for groundwater protection at the Savannah River Plant (SRP). For purposes of this EIA, the areas within the plant have been separated into 26 functional groups based primarily on hydrogeologic setting and types of disposed waste materials. The overall objective is to provide an appropriate quantitative assessment of the environmental impacts from past and future operations within each functional group. The analysis from each functional group will be integrated to assess the impacts of plant-wide operations. A flexible approach to quantifying the impacts using several methods of quantitative analysis is being employed. Numerical flow and transport modeling is one method being applied to several functional groups. The scope of work can be divided into four broad categories: (1) Data Review and Conceptual Model Development, (2) Groundwater Flow Model Construction and Refinement, (3) Solute Transport Model Construction, and (4) Remedial Alternative Simulations. The major topics covered in this report are: (1) summary of the hydrogeologic conditions of the area, (2) observed flow velocities at the study site, (3) a summary of results from the preliminary flow modeling effort, (4) flow model refinement and results, and (5) particle tracking analyses based on the refined flow model.

  10. Soil gas radon–thoron monitoring in Dharamsala area of north-west Himalayas, India using solid state nuclear track detectors

    Indian Academy of Sciences (India)

    Gulshan Kumar; Arvind Kumar; Vivek Walia; Jitender Kumar; Vikash Gupta; Tsanyao Frank Yang; Surinder Singh; Bikramjit Singh Bajwa

    2013-10-01

    The study described here is based on the measurements of soil gas radon–thoron concentrations performed at Dharamsala region of north-west (NW) Himalayas, India. The study area is tectonically and environmentally significant and shows the features of ductile shear zone due to the presence of distinct thrust planes. Solid state nuclear track detectors (LR-115 films) have been used for the soil gas radon–thoron monitoring. Twenty five radon–thoron discriminators with LR-115 films were installed in the borehole of about 50 cm in the study areas. The recorded radon concentration varies from 1593 to 13570 Bq/m3 with an average value of 5292 Bq/m3. The recorded thoron concentration varies from 223 to 2920 Bq/m3 with an average value of 901 Bq/m3. The anomalous value of radon–thoron has been observed near to the faults like main boundary thrust (MBT and MBT2) as well as neotectonic lineaments in the region.

  11. The CMS silicon strip tracker

    International Nuclear Information System (INIS)

    The Silicon Strip Tracker (SST) is the intermediate part of the CMS Central Tracker System. SST is based on microstrip silicon devices and in combination with pixel detectors and the Microstrip Gas Chambers aims at performing pattern recognition, track reconstruction and momentum measurements for all tracks with pT≥2 GeV/c originating from high luminosity interactions at √s=14 TeV at LHC. We aim at exploiting the advantages and the physics potential of the precise tracking performance provided by the microstrip silicon detectors on a large scale apparatus and in a much more difficult environment than ever. In this paper we describe the actual SST layout and the readout system. (author)

  12. Five-year tracking of Plasmodium falciparum allele frequencies in a holoendemic area with indistinct seasonal transitions

    Directory of Open Access Journals (Sweden)

    Akala HM

    2014-11-01

    Full Text Available Hoseah M Akala, Angela O Achieng, Fredrick L Eyase, Dennis W Juma, Luiser Ingasia, Agnes C Cheruiyot, Charles Okello, Duke Omariba, Eunice A Owiti, Catherine Muriuki, Redemptah Yeda, Ben Andagalu, Jacob D Johnson, Edwin Kamau Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya Background: The renewed malaria eradication efforts require an understanding of the seasonal patterns of frequency of polymorphic variants in order to focus limited funds productively. Although cross-sectional studies in holoendemic areas spanning a single year could be useful in describing parasite genotype status at a given point, such information is inadequate in describing temporal trends in genotype polymorphisms. For Plasmodium falciparum isolates from Kisumu District Hospital, Plasmodium falciparum chloroquine-resistance transporter gene (Pfcrt-K76T and P. falciparum multidrug resistance gene 1 (PfMDR1-N86Y, were analyzed for polymorphisms and parasitemia changes in the 53 months from March 2008 to August 2012. Observations were compared with prevailing climatic factors, including humidity, rainfall, and temperature. Methods: Parasitemia (the percentage of infected red blood cells per total red blood cells was established by microscopy for P. falciparum malaria-positive samples. P. falciparum DNA was extracted from whole blood using a Qiagen DNA Blood Mini Kit. Single nucleotide polymorphism identification at positions Pfcrt-K76T and PfMDR1-N86Y was performed using real-time polymerase chain reaction and/or sequencing. Data on climatic variables were obtained from http://www.tutiempo.net/en/. Results: A total of 895 field isolates from 2008 (n=169, 2009 (n=161, 2010 (n=216, 2011 (n=223, and 2012 (n=126 showed large variations in monthly frequency of PfMDR1-N86Y and Pfcrt-K76T as the mutant genotypes decreased from 68.4%±15% and 38.1%±13% to

  13. Track reconstruction in CMS high luminosity environment

    CERN Document Server

    Goetzmann, Christophe

    2014-01-01

    The CMS tracker is the largest silicon detector ever built, covering 200 square meters and providing an average of 14 high-precision measurements per track. Tracking is essential for the reconstruction of objects like jets, muons, electrons and tau leptons starting from the raw data from the silicon pixel and strip detectors. Track reconstruction is widely used also at trigger level as it improves objects tagging and resolution.The CMS tracking code is organized in several levels, known as iterative steps, each optimized to reconstruct a class of particle trajectories, as the ones of particles originating from the primary vertex or displaced tracks from particles resulting from secondary vertices. Each iterative step consists of seeding, pattern recognition and fitting by a kalman filter, and a final filtering and cleaning. Each subsequent step works on hits not yet associated to a reconstructed particle trajectory.The CMS tracking code is continuously evolving to make the reconstruction computing load compat...

  14. Tracking and back-tracking

    OpenAIRE

    Lorenzo Pigueiras, Eduardo; Narvarte Fernandez, Luis; Muñoz Cano, Javier

    2011-01-01

    This paper presents a review of back-tracking geometry not only for single axis but also for two-axis tracking and analyses the corresponding energy gains. It compares the different back-tracking strategies with the ideal tracking in terms of energy yield concluding, on the one hand, that back-tracking is more useful for single horizontal axis than for the single vertical one, and on the other hand, that back-tracking is more efficient when applied in the primary axis of a two-axis tracker

  15. Particle tracking with scintillating fibres

    CERN Document Server

    D'Ambrosio, C; Leutz, H; Puertolas, D

    1996-01-01

    This article presents our R&D-work on particle tracking with scintillating fibres. We have developed new fibre dyes, more efficient fibre cladding, coherent fibre bundles with improved packing fraction and a new fibre readout technique (ISPA-tube). Altogether, these new developments increased the hit density of fine grain (60 µm) fibres by about 7 times. This results in mini-tracks per 2.5 mm fibre layer rather than in single hits only and enhances the track reconstruction efficiency to nearly 100 %. Compared with competing tracking methods (silicon strips, MSGCs), our scintillating fibres are superior in hit numbers per radiation length and in the 2-track resolution. They require much less readout channels and consequently no cooling provisions to remove their electronic heat.

  16. Quality of Slab Track Construction – Track Alignment Design and Track Geometry

    Directory of Open Access Journals (Sweden)

    Šestáková Janka

    2015-05-01

    Full Text Available The slab track superstructure design (without ballast is a perspective construction especially for building tunnels and bridges in the modernized sections of railway tracks in Slovakia. Monitoring of the structure described in this article is focused on the transition areas between standard structure with ballast and slab track construction.

  17. Quality of Slab Track Construction – Track Alignment Design and Track Geometry

    OpenAIRE

    Šestáková Janka

    2015-01-01

    The slab track superstructure design (without ballast) is a perspective construction especially for building tunnels and bridges in the modernized sections of railway tracks in Slovakia. Monitoring of the structure described in this article is focused on the transition areas between standard structure with ballast and slab track construction.

  18. Quality of Slab Track Construction - Track Alignment Design and Track Geometry

    Science.gov (United States)

    Šestáková, Janka

    2015-05-01

    The slab track superstructure design (without ballast) is a perspective construction especially for building tunnels and bridges in the modernized sections of railway tracks in Slovakia. Monitoring of the structure described in this article is focused on the transition areas between standard structure with ballast and slab track construction.

  19. Silicon drift-chamber prototype for the upgrade of the UA6 experiment at the CERN p /bar char/p collider

    International Nuclear Information System (INIS)

    A large-area (≅ 4 x 4 cm2) silicon drift chamber has been designed and constructed in order to investigate its possible use in the UA6 experiment. The drift chamber will supply unambiguously (x,y) space points on each track; each arm of the UA6 spectrometer will be provided with two layers of drift detectors. 12 refs., 4 figs

  20. Roadmap on silicon photonics

    Science.gov (United States)

    Thomson, David; Zilkie, Aaron; Bowers, John E.; Komljenovic, Tin; Reed, Graham T.; Vivien, Laurent; Marris-Morini, Delphine; Cassan, Eric; Virot, Léopold; Fédéli, Jean-Marc; Hartmann, Jean-Michel; Schmid, Jens H.; Xu, Dan-Xia; Boeuf, Frédéric; O’Brien, Peter; Mashanovich, Goran Z.; Nedeljkovic, M.

    2016-07-01

    Silicon photonics research can be dated back to the 1980s. However, the previous decade has witnessed an explosive growth in the field. Silicon photonics is a disruptive technology that is poised to revolutionize a number of application areas, for example, data centers, high-performance computing and sensing. The key driving force behind silicon photonics is the ability to use CMOS-like fabrication resulting in high-volume production at low cost. This is a key enabling factor for bringing photonics to a range of technology areas where the costs of implementation using traditional photonic elements such as those used for the telecommunications industry would be prohibitive. Silicon does however have a number of shortcomings as a photonic material. In its basic form it is not an ideal material in which to produce light sources, optical modulators or photodetectors for example. A wealth of research effort from both academia and industry in recent years has fueled the demonstration of multiple solutions to these and other problems, and as time progresses new approaches are increasingly being conceived. It is clear that silicon photonics has a bright future. However, with a growing number of approaches available, what will the silicon photonic integrated circuit of the future look like? This roadmap on silicon photonics delves into the different technology and application areas of the field giving an insight into the state-of-the-art as well as current and future challenges faced by researchers worldwide. Contributions authored by experts from both industry and academia provide an overview and outlook for the silicon waveguide platform, optical sources, optical modulators, photodetectors, integration approaches, packaging, applications of silicon photonics and approaches required to satisfy applications at mid-infrared wavelengths. Advances in science and technology required to meet challenges faced by the field in each of these areas are also addressed together with

  1. Low-temperature silicon thin films for large-area electronics: Device fabrication using soft lithography and laser-crystallization by sequential lateral solidification

    Science.gov (United States)

    Jin, Hyun-Chul

    This work demonstrates possible routes for fabricating large-area electronic devices on glass or plastic substrates using low-temperature materials deposition and soft lithographic device patterning. Hydrogenated amorphous silicon (a-Si:H) and polycrystalline silicon (poly-Si) have been extensively studied as the semiconducting material for flat panel displays and solar cells. On glass substrates, we have deposited a-Si:H films at a temperature lower than 125°C, and we have used pulsed excimer laser crystallization in the sequential lateral solidification (SLS) regime to fabricate poly-Si films. We use micromolding in capillaries (MIMIC), a form of soft lithography involving micrometer-scale polymer molding, as a means to fabricate amorphous silicon thin-film transistors (TFTs), and photoconductive sensor arrays on both planar and curved substrates. The use of non-planar substrates has captured considerable attention in the field because it would open up new applications and new designs. Field-effect transistors made by SLS poly-Si show excellent mobility and on/off current ratio; however, the microstructure of the material had never been well documented. We determined the microtexture using electron backscattering diffraction (EBSD): the first crystallites formed in the a-Si layer are random; along the direction of the solidification, a strong in-plane orientation quickly develops due to competitive growth and occlusion. The misorientation angle between neighboring grains is also analyzed. A large fraction of the boundaries within the material are low-angle and coincidence site lattice (CSL) types. We discuss the implications of the findings on the defect generation mechanism and on the electrical properties of the films. We have analyzed the electrical properties of SLS poly-Si films on oxidized Si wafer using the pseudo-MOSFET geometry; the majority carrier mobility is extracted from the transconductance. However, the data are non-ideal due to large contact

  2. The CMS silicon tracker

    International Nuclear Information System (INIS)

    The new silicon tracker layout (V4) is presented. The system aspects of the construction are discussed together with the expected tracking performance. Because of the high radiation environment in which the detectors will operate, particular care has been devoted to the study of the characteristics of heavily irradiated detectors. This includes studies on performance (charge collection, cluster size, resolution, efficiency) as a function of the bias voltage, integrated fluence, incidence angle and temperature. (author)

  3. The silicon sensor for the compact muon solenoid tracker. Control of the fabrication process

    International Nuclear Information System (INIS)

    The Compact Muon Solenoid (CMS) is one of the experiments at the Large Hadron Collider (LHC) under construction at CERN. The inner tracking system of this experiment consists of the world largest Silicon Strip Tracker (SST). In total, 24,244 silicon sensors are implemented covering an area of 206 m2. To construct this large system and to ensure its functionality for the full lifetime of ten years under the hard LHC condition, a detailed quality assurance program has been developed. This paper describes the strategy of the Process Qualification Control to monitor the stability of the fabrication process throughout the production phase and the results obtained are shown. (authors)

  4. The silicon sensors for the Compact Muon Solenoid tracker—design and qualification procedure

    Science.gov (United States)

    Agram, J.-L.; Angarano, M. M.; Assouak, S.; Bergauer, T.; Bilei, G. M.; Borrello, L.; Brianzi, M.; Civinini, C.; Dierlamm, A.; Dinu, N.; Demaria, N.; Feld, L.; Focardi, E.; Fontaine, J.-C.; Forton, E.; Furgeri, A.; Gregoire, Gh.; Hartmann, F.; Honma, A.; Juillot, P.; Kartashov, D.; Krammer, M.; Macchiolo, A.; Mannelli, M.; Messineo, A.; Migliore, E.; Militaru, O.; Piasecki, C.; Santinelli, R.; Sentenac, D.; Servoli, L.; Starodumov, A.; Tonelli, G.; Wang, J.

    2004-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments at the Large Hadron Collider (LHC) under construction at CERN. Its inner tracking system consist of the world largest Silicon Strip Tracker (SST). In total it implements 24,244 silicon sensors covering an area of 206 m2. To construct a large system of this size and ensure its functionality for the full lifetime of 10 years under LHC condition, the CMS collaboration developed an elaborate design and a detailed quality assurance program. This paper describes the strategy and shows first results on sensor qualification.

  5. The Silicon Sensors for the Compact Muon Solenoid Tracker - Design and Qualification Procedure

    CERN Document Server

    Agram, Jean-Laurent; Assouak, Samia; Bergauer T.; Bilei, Gian Mario; Borrello, Laura; Brianzi, Mirko; Civinini, Carlo; Dierlamm, Alexander; Dinu, Nicoleta; Demaria, Natale; Feld, Lutz; Focardi, Ettore; Fontaine, Jean-Charles; Forton, Eric; Furgeri, Alexander; Hartmann, Frank; Honma, Alan; Juillot, Pierre; Kartashov, Dmitry; Krammer, Manfred; Macchiolo, Anna; Mannelli, Marcello; Messineo, Alberto; Migliore, Ernesto; Militaru, Otilia; Piasecki, Christian; Santinelli, Roberto; Sentenac, Daniel; Servoli, Leonello; Starodumov, Andrei; Tonelli, Guido; Wang, Jason

    2003-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments at the Large Hadron Collider (LHC) under construction at CERN. Its inner tracking system consist of the world largest Silicon Strip Tracker (SST). In total it implements 24244 silicon sensors covering an area of 206 m^2. To construct a large system of this size and ensure its functionality for the full lifetime of ten years under LHC condition, the CMS collaboration developed an elaborate design and a detailed quality assurance program. This paper describes the strategy and shows first results on sensor qualification.

  6. Development of large area nanostructured silicon-hydrogen alloy material with improved stability for solar cell application by argon dilution method

    Science.gov (United States)

    Dey, Arka; Das, Mrinmay; Datta, Joydeep; Jana, Rajkumar; Dhar, Joydeep; Sil, Sayantan; Biswas, Debasish; Banerjee, Chandan; Ray, Partha Pratim

    2016-07-01

    Here we have presented the results of large area (30 × 30 cm2) silicon-hydrogen alloy material and solar cell by argon dilution method. As an alternative to hydrogen dilution, argon dilution method has been applied to develop single junction solar cell with appreciable stability. Optimization of deposition conditions revealed that 95% argon dilution gives a nanostructured material with improved transport property and less light induced degradation. The minority carrier diffusion length (L d ) and mobility-lifetime (μτ) product of the material with 95% argon dilution degrades least after light soaking. Also the density of states (DOS) below conduction level reveals that this material is less defective. Solar cell with this argon diluted material has been fabricated with all the layers deposited by argon dilution method. Finally we have compared the argon diluted solar cell results with the optimized hydrogen diluted solar cell. Light soaking study proves that it is possible to develop stable solar cell on large area by argon dilution method and that the degradation of argon diluted solar cell is less than that of hydrogen diluted one. [Figure not available: see fulltext.

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

    Energy Technology Data Exchange (ETDEWEB)

    Unno, Y., E-mail: yoshinobu.unno@kek.jp [Institute of Particle and Nuclear Study, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Edwards, S.O.; Pyatt, S.; Thomas, J.P.; Wilson, J.A. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Kierstead, J.; Lynn, D. [Brookhaven National Laboratory, Physics Department and Instrumentation Division, Upton, NY 11973-5000 (United States); Carter, J.R.; Hommels, L.B.A.; Robinson, D. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Bloch, I.; Gregor, I.M.; Tackmann, K. [Josef Stefan Institute and Department of Physics, University of Ljubljana, Ljubljana (Slovenia); Betancourt, C.; Jakobs, K.; Kuehn, S.; Mori, R.; Parzefall, U.; Wiik-Fucks, L. [Physikalisches Institut, Universitt Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Clark, A. [DPNC, University of Geneva, 24, Quai Ernest-Ansermet, CH-1211 Genve 4 (Switzerland); and others

    2014-11-21

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

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

    International Nuclear Information System (INIS)

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

  9. Development Of Protocols For Simultaneous Measurements Of Rn, Tn Using Nuclear Track Detectors And Trial Application In Mining Areas Of Vietnam

    International Nuclear Information System (INIS)

    Radioactive gases Radon (Rn) and Thoron (Tn) contribute of more than 50% of natural radiation dose. However, separate measurements of Rn and Tn have not been paid enough attention. An Intergovernmental Cooperation Project was conducted at the Institute for Nuclear Science and Technology with the help from Hungarian experts. The main tasks of the project were to finalize 02 protocols for simultaneous measurements of Rn and Tn using nuclear track detectors and to test these protocols in investigating the concentrations of Rn and Tn, calculating the natural dose due to Rn and Tn, and evaluating the increased radiation dose and radiation safety due to mining activities. Main results of the project include 02 protocols for simultaneous measurements of Rn and Tn and the test results in the mining areas. Rn and Tn concentrations inside the coal mining tunnels are in the average level of Vietnam and the world. Tn concentration inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant was found to be very high, up to 2931 Bq/m3. Based on annual effective dose calculation, workers inside the factory for separating Zircon at the Ha Tinh Zircon Processing Plant could receive an annual effective dose due to Rn and Tn of 4.890 mSv/year, and the increasing dose of 4.710 mSv/year is for higher than 1 mSv/year recommended by the IAEA. (author)

  10. Development of an adjoint model of GRAPES-CUACE and its application in tracking influential haze source areas in north China

    Science.gov (United States)

    An, Xing Qin; Xian Zhai, Shi; Jin, Min; Gong, Sunling; Wang, Yu

    2016-06-01

    The aerosol adjoint module of the atmospheric chemical modeling system GRAPES-CUACE (Global-Regional Assimilation and Prediction System coupled with the CMA Unified Atmospheric Chemistry Environment) is constructed based on the adjoint theory. This includes the development and validation of the tangent linear and the adjoint models of the three parts involved in the GRAPES-CUACE aerosol module: CAM (Canadian Aerosol Module), interface programs that connect GRAPES and CUACE, and the aerosol transport processes that are embedded in GRAPES. Meanwhile, strict mathematical validation schemes for the tangent linear and the adjoint models are implemented for all input variables. After each part of the module and the assembled tangent linear and adjoint models is verified, the adjoint model of the GRAPES-CUACE aerosol is developed and used in a black carbon (BC) receptor-source sensitivity analysis to track influential haze source areas in north China. The sensitivity of the average BC concentration over Beijing at the highest concentration time point (referred to as the Objective Function) is calculated with respect to the BC amount emitted over the Beijing-Tianjin-Hebei region. Four types of regions are selected based on the administrative division or the sensitivity coefficient distribution. The adjoint sensitivity results are then used to quantify the effect of reducing the emission sources at different time intervals over different regions. It is indicated that the more influential regions (with relatively larger sensitivity coefficients) do not necessarily correspond to the administrative regions. Instead, the influence per unit area of the sensitivity selected regions is greater. Therefore, controlling the most influential regions during critical time intervals based on the results of the adjoint sensitivity analysis is much more efficient than controlling administrative regions during an experimental time period.

  11. Porous silicon gettering

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Menna, P.; Pitts, J.R. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    The authors have studied a novel extrinsic gettering method that uses the large surface areas produced by a porous-silicon etch as gettering sites. The annealing step of the gettering used a high-flux solar furnace. They found that a high density of photons during annealing enhanced the impurity diffusion to the gettering sites. The authors used metallurgical-grade Si (MG-Si) prepared by directional solidification casing as the starting material. They propose to use porous-silicon-gettered MG-Si as a low-cost epitaxial substrate for polycrystalline silicon thin-film growth.

  12. Silicon etch process

    International Nuclear Information System (INIS)

    A silicon etch process wherein an area of silicon crystal surface is passivated by radiation damage and non-planar structure produced by subsequent anisotropic etching. The surface may be passivated by exposure to an energetic particle flux - for example an ion beam from an arsenic, boron, phosphorus, silicon or hydrogen source, or an electron beam. Radiation damage may be used for pattern definition and/or as an etch stop. Ethylenediamine pyrocatechol or aqueous potassium hydroxide anisotropic etchants may be used. The radiation damage may be removed after etching by thermal annealing. (author)

  13. Silicon detectors

    International Nuclear Information System (INIS)

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  14. Study on Silicon detectors

    International Nuclear Information System (INIS)

    Prototypes of Silicon microstrip detectors and Silicon large area detectors (3x2 cm2), realized directly by our group, either by ion implantation or by diffusion are presented. The physical detector characteristics and their performances determined by exposing them to different radioactive sources and the results of extensive tests on passivation, where new technological ways have been investigated, are discussed. The calculation of the different terms contributing to the total dark current is reported

  15. Large area supersonic jet epitaxy of AlN, GaN, and SiC on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Lauhon, L.J.; Ustin, S.A.; Ho, W. [Cornell Univ., Ithaca, NY (United States). Dept. of Physics

    1997-12-31

    AlN, GaN, and SiC thin films were grown on 100 mm diameter Si(111) and Si(100) substrates using Supersonic Jet Epitaxy (SJE). Precursor gases were seeded in lighter mass carrier gases and free jets were formed using novel slit-jet apertures. The jet design, combined with substrate rotation, allowed for a uniform flux distribution over a large area of a 100 mm wafer at growth pressures of 1--20 mTorr. Triethylaluminum, triethylgallium, and ammonia were used for nitride growth, while disilane, acetylene, and methylsilane were used for SiC growth. The films were characterized by in situ optical reflectivity, x-ray diffraction (XRD), atomic force microscopy (AFM), and spectroscopic ellipsometry (SE).

  16. Persistent Aerial Tracking

    KAUST Repository

    Mueller, Matthias

    2016-04-13

    In this thesis, we propose a new aerial video dataset and benchmark for low altitude UAV target tracking, as well as, a photo-realistic UAV simulator that can be coupled with tracking methods. Our benchmark provides the rst evaluation of many state of-the-art and popular trackers on 123 new and fully annotated HD video sequences captured from a low-altitude aerial perspective. Among the compared trackers, we determine which ones are the most suitable for UAV tracking both in terms of tracking accuracy and run-time. We also present a simulator that can be used to evaluate tracking algorithms in real-time scenarios before they are deployed on a UAV "in the field", as well as, generate synthetic but photo-realistic tracking datasets with free ground truth annotations to easily extend existing real-world datasets. Both the benchmark and simulator will be made publicly available to the vision community to further research in the area of object tracking from UAVs. Additionally, we propose a persistent, robust and autonomous object tracking system for unmanned aerial vehicles (UAVs) called Persistent Aerial Tracking (PAT). A computer vision and control strategy is applied to a diverse set of moving objects (e.g. humans, animals, cars, boats, etc.) integrating multiple UAVs with a stabilized RGB camera. A novel strategy is employed to successfully track objects over a long period, by \\'handing over the camera\\' from one UAV to another. We integrate the complete system into an off-the-shelf UAV, and obtain promising results showing the robustness of our solution in real-world aerial scenarios.

  17. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

    Science.gov (United States)

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M.; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M.

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm2. The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm2, a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging. PMID:27319783

  18. Evaluation of the bulk and strip characteristics of large area n-in-p silicon sensors intended for a very high radiation environment

    Science.gov (United States)

    Bohm, J.; Mikestikova, M.; Affolder, A. A.; Allport, P. P.; Bates, R.; Betancourt, C.; Brown, H.; Buttar, C.; Carter, J. R.; Casse, G.; Chen, H.; Chilingarov, A.; Cindro, V.; Clark, A.; Dawson, N.; Dewilde, B.; Doherty, F.; Dolezal, Z.; Eklund, L.; Fadeyev, V.; Ferrere, D.; Fox, H.; French, R.; Garcia, C.; Gerling, M.; Gonzalez Sevilla, S.; Gorelov, I.; Greenall, A.; Grillo, A. A.; Hara, K.; Hatano, H.; Hoeferkamp, M.; Hommels, L. B. A.; Ikegami, Y.; Jakobs, K.; Kierstead, J.; Kodys, P.; Köhler, M.; Kohriki, T.; Krambergen, G.; Lacasta, C.; Li, Z.; Lindgren, S.; Lynn, D.; Maddock, P.; Mandic, I.; Marti I Garcia, S.; Martinez-McKinney, F.; Maunu, R.; McCarthy, R.; Metcalfe, J.; Mikuz, M.; Minano, M.; Mitsui, S.; O'Shea, V.; Paganis, S.; Parzefall, U.; Puldon, D.; Robinson, D.; Sadrozinski, H. F.-W.; Sattari, S.; Schamberger, D.; Seidel, S.; Seiden, A.; Soldevila, U.; Terada, S.; Toms, K.; Tsionou, D.; Unno, Y.; von Wilpert, J.; Wormald, M.; Wright, J.; Yamada, M.

    2011-04-01

    The ATLAS collaboration R&D group “Development of n-in-p Silicon Sensors for very high radiation environment” has developed single-sided p-type 9.75 cm×9.75 cm sensors with an n-type readout strips having radiation tolerance against the 1015 1-MeV neutron equivalent (neq)/cm2 fluence expected in the Super Large Hadron Collider. The compiled results of an evaluation of the bulk and strip parameter characteristics of 19 new non-irradiated sensors manufactured by Hamamatsu Photonics are presented in this paper. It was verified in detail that the sensors comply with the technical specifications required before irradiation. The reverse bias voltage dependence of various parameters, frequency dependence of tested capacitances, and strip scans of more than 23,000 strips as a test of parameter uniformity and strip quality over the whole sensor area have been carried out at Stony Brook University, Cambridge University, University of Geneva, and Academy of Sciences of CR and Charles University in Prague. No openings, shorts, or pinholes were observed on all tested strips, confirming the high quality of sensors made by Hamamatsu Photonics.

  19. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability.

    Science.gov (United States)

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging. PMID:27319783

  20. Crescimento de diamante CVD em substratos de silício de grande área CVD Diamond growth in the silicon substrates of large area

    Directory of Open Access Journals (Sweden)

    João Roberto Moro

    2010-06-01

    Full Text Available Realizaram-se crescimentos de filmes de diamante por deposição química de vapor (CVD, do inglês Chemical Vapor Deposition em substratos de silício (100, de grande área (80 cm², em um reator de filamento quente (HFCVD, com taxas de crescimento superiores a 1,5 µm/h. Foi realizado o crescimento das amostras com diferentes fluxos gasosos e diferentes porcentagens de metano (CH4 em hidrogênio (H2. As amostras foram caracterizadas por microscopia óptica, eletrônica de varredura e por espectroscopia de espalhamento Raman. Tais análises acusaram a presença de diamante de alta pureza em todas as amostras.Diamond films were grown through Chemical Vapor Deposition (CVD in silicon substrates (100 of large area (80 cm², in a hot filament chemical vapor deposition (HFCVD, with growth rates over 1,5 µm/h. The growth of samples was made with different gaseous fluxes and different methane percentages (CH4 in hydrogen (H2. The samples were analyzed through optical microscopy, Scanning Electron Microscopy and Raman spectroscopy scattering. Such analyzes showed the presence of a high purity diamond in all samples.

  1. Impact of carrier recombination on fill factor for large area heterojunction crystalline silicon solar cell with 25.1% efficiency

    Science.gov (United States)

    Adachi, Daisuke; Hernández, José Luis; Yamamoto, Kenji

    2015-12-01

    We have achieved a certified 25.1% conversion efficiency in a large area (151.9 cm2) heterojunction (HJ) crystalline Si (c-Si) solar cell with amorphous Si (a-Si) passivation layer. This efficiency is a world record in a both-side-contacted c-Si solar cell. Our high efficiency HJ c-Si solar cells are investigated from the standpoint of the effective minority carrier lifetime (τe), and the impact of τe on fill factor (FF) is discussed. The τe measurements of our high efficiency HJ c-Si solar cells reveal that τe at an injection level corresponding to an operation point of maximum power is dominated by the carrier recombination at the a-Si/c-Si interface. By optimization of the process conditions, the carrier recombination at the a-Si/c-Si interface is reduced, which leads to an improvement of the FF by an absolute value of 2.7%, and a conversion efficiency of 25.1% has been achieved. These results indicate that the reduction of carrier recombination centers at the a-Si/c-Si interface should be one of the most crucial issues for further improvement of FF even in the HJ c-Si solar cells with efficiency over 25%.

  2. Tracking Land Use/Land Cover Dynamics in Cloud Prone Areas Using Moderate Resolution Satellite Data: A Case Study in Central Africa

    Directory of Open Access Journals (Sweden)

    Bikash Basnet

    2015-05-01

    Full Text Available Tracking land surface dynamics over cloud prone areas with complex mountainous terrain is an important challenge facing the Earth Science community. One such region is the Lake Kivu region in Central Africa. We developed a processing chain to systematically monitor the spatio-temporal land use/land cover dynamics of this region over the years 1988, 2001, and 2011 using Landsat data, complemented by ancillary data. Topographic compensation was performed on Landsat reflectances to avoid the strong illumination angle impacts and image compositing was used to compensate for frequent cloud cover and thus incomplete annual data availability in the archive. A systematic supervised classification was applied to the composite Landsat imagery to obtain land cover thematic maps with overall accuracies of 90% and higher. Subsequent change analysis between these years found extensive conversions of the natural environment as a result of human related activities. The gross forest cover loss for 1988–2001 and 2001–2011 period was 216.4 and 130.5 thousand hectares, respectively, signifying significant deforestation in the period of civil war and a relatively stable and lower deforestation rate later, possibly due to conservation and reforestation efforts in the region. The other dominant land cover changes in the region were aggressive subsistence farming and urban expansion displacing natural vegetation and arable lands. Despite limited data availability, this study fills the gap of much needed detailed and updated land cover change information for this biologically important region of Central Africa. These multi-temporal datasets will be a valuable baseline for land use managers in the region interested in developing ecologically sustainable land management strategies and measuring the impacts of biodiversity conservation efforts.

  3. Characterization of sources and loadings of fecal pollutants using microbial source tracking assays in urban and rural areas of the Grand River Watershed, Southwestern Ontario.

    Science.gov (United States)

    Lee, Dae-Young; Lee, Hung; Trevors, Jack T; Weir, Susan C; Thomas, Janis L; Habash, Marc

    2014-04-15

    Sources of fecal water pollution were assessed in the Grand River and two of its tributaries (Ontario, Canada) using total and host-specific (human and bovine) Bacteroidales genetic markers in conjunction with reference information, such as land use and weather. In-stream levels of the markers and culturable Escherichia coli were also monitored during multiple rain events to gain information on fecal loadings to catchment from diffuse sources. Elevated human-specific marker levels were accurately identified in river water impacted by a municipal wastewater treatment plant (WWTP) effluent and at a downstream site in the Grand River. In contrast, the bovine-specific marker showed high levels of cattle fecal pollution in two tributaries, both of which are characterized as intensely farmed areas. The bovine-specific Bacteroidales marker increased with rainfall in the agricultural tributaries, indicating enhanced loading of cattle-derived fecal pollutants to river from non-point sources following rain events. However, rain-triggered fecal loading was not substantiated in urban settings, indicating continuous inputs of human-originated fecal pollutants from point sources, such as WWTP effluent. This study demonstrated that the Bacteroidales source tracking assays, in combination with land use information and hydrological data, may provide additional insight into the spatial and temporal distribution of source-specific fecal contamination in streams impacted by varying land uses. Using the approach described in this study may help to characterize impacted water sources and to design targeted land use management plans in other watersheds in the future. PMID:24509346

  4. Transformational silicon electronics

    KAUST Repository

    Rojas, Jhonathan Prieto

    2014-02-25

    In today\\'s traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 μm), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry\\'s most advanced high-κ/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications. © 2014 American Chemical Society.

  5. Large-area, wafer-scale epitaxial growth of germanium on silicon and integration of high-performance transistors

    Science.gov (United States)

    Ghosh, Swapnadip

    Building on a unique two-step, simple MBE growth technique, we have investigated possible dislocation locking mechanisms by dopant impurities, coupled with artificially introduced oxygen. In the case of n-type Ge grown on Si, our materials characterization indicates that the dislocation density (DD) can reach the ˜105 cm-2 level, compared to p-type and undoped Ge on Si (GoS). We note that our Ge film covers the entire underlying Si substrate at the wafer scale without mesas or limited-area growth. In this presentation, we will focus on the use of n-type impurity (phosphorus) diffusing from the Si substrate and the introduction of O at the Ge-Si interface. The O is introduced by growing a thin chemical SiO2 layer on top of the Si substrate before Ge epitaxy begins. Z-contrast cross-sectional TEM images suggest the presence of oxygen precipitates in n-type Ge, whereas these precipitates appear absent in p-type Ge. These oxygen precipitates are known to lock the dislocations. Supporting the argument of precipitate formation, the TEM shows fringes due to various phase boundaries that exist at the precipitate/Ge-crystal interface. We speculate that the formation of phosphorus (P) segregation resulting from slow diffusion of P through precipitates at the precipitate/Ge-crystal interface facilitates dislocation locking. Impurity segregations in turn suppress O concentration in n-type Ge indicating reduced magnitude of DD that appears on the top surface of n-Ge compared to p-Ge film. The O concentrations (1017 to 1018 cm-3) in the n- and p-type GoS films are measured using secondary ionization mass spectroscopy. We also demonstrate the technique to improve the Ge epitaxial quality by inserting air-gapped, SiO2-based nanoscale templates within epitaxially grown Ge on Si. We have shown that the template simultaneously filters threading dislocations propagating from Ge-Si interface and relieves the film stress caused by the TEC mismatch. The finite element modeling stress

  6. Development of radiation hard radiation detectors : differences between Czochralski silicon and float zone silicon

    OpenAIRE

    Tuominen, Eija

    2003-01-01

    The purpose of this work was to develop radiation hard silicon detectors. Radiation detectors made of silicon are cost effective and have excellent position resolution. Therefore, they are widely used for track finding and particle analysis in large high-energy physics experiments. Silicon detectors will also be used in the CMS (Compact Muon Solenoid) experiment that is being built at the LHC (Large Hadron Collider) accelerator at CERN (European Organisation for Nuclear Research). This work w...

  7. Silicon strip detector qualification for the CMS experiment

    CERN Document Server

    Kaußen, Gordon

    2008-01-01

    The Compact Muon Solenoid (CMS) is one of the four experiments being installed at the Large Hadron Collider (LHC) which is located at the european organization for nuclear research CERN in Geneva. This proton-proton collider will explore a new energy regime of up to 14TeV center-of-mass energy. To provide the best spatial resolution for the particle trajectory reconstruction and a very fast readout, the inner tracking system of CMS is build up of silicon detectors with a pixel tracker in the center surrounded by a strip tracker. The silicon strip tracker consists of so-called modules representing the smallest detection unit of the tracking device. These modules are mounted on higher-level structures called shells in the tracker inner barrel (TIB), rods in the tracker outer barrel (TOB), disks in the tracker inner disks (TID) and petals in the tracker end caps (TEC). The entire strip tracker spans an active area of about 198m2 and consists of approximately 16000 modules. Before the silicon sensors were assembl...

  8. Tracking subsystem of the SOFIA telescope

    Science.gov (United States)

    Bittner, Hermann; Braeuninger, Christoph; Dierks, Andreas; Erdmann, Matthias; Erhard, Markus; Lattner, Klaus; Schmolke, Juergen

    2000-06-01

    The Tracking Subsystem of the SOFIA telescope consists of three high performance imagers and a dedicated tracking control unit. There are two boresighted imagers for target acquisition and tracking, one with a wide (6 degrees) and one with a fine (70 arcmin) field-of-view, and one main- telescope-optics sharing imager with a narrow field-of-view (8 arcmin) for high performance tracking. From the recorded stellar images, tracking error signals are generated by the tracker controller. The tracker controller has several features to support various tracking schemes such as tracking the telescope as an inertial platform, on- axis/offset tracking, and limb tracking. The tracker has three modes, i.e. positioning, tracking and `override'. Special features are the handling of so-called areas-of- interest in the inertial reference frame and the external imager synchronization. The paper presents the design and functional/operational performance of the imagers and the tracking control unit.

  9. Development of Tandem Amorphous/Microcrystalline Silicon Thin-Film Large-Area See-Through Color Solar Panels with Reflective Layer and 4-Step Laser Scribing for Building-Integrated Photovoltaic Applications

    OpenAIRE

    Chin-Yi Tsai; Chin-Yao Tsai

    2014-01-01

    In this work, tandem amorphous/microcrystalline silicon thin-film large-area see-through color solar modules were successfully designed and developed for building-integrated photovoltaic applications. Novel and key technologies of reflective layers and 4-step laser scribing were researched, developed, and introduced into the production line to produce solar panels with various colors, such as purple, dark blue, light blue, silver, golden, orange, red wine, and coffee. The highest module power...

  10. VEGA: A low-power front-end ASIC for large area multi-linear X-ray silicon drift detectors: Design and experimental characterization

    International Nuclear Information System (INIS)

    We present the design and the first experimental characterization of VEGA, an Application Specific Integrated Circuit (ASIC) designed to read out large area monolithic linear Silicon Drift Detectors (SDD’s). VEGA consists of an analog and a digital/mixed-signal section to accomplish all the functionalities and specifications required for high resolution X-ray spectroscopy in the energy range between 500 eV and 50 keV. The analog section includes a charge sensitive preamplifier, a shaper with 3-bit digitally selectable shaping times from 1.6 µs to 6.6 µs and a peak stretcher/sample-and-hold stage. The digital/mixed-signal section includes an amplitude discriminator with coarse and fine threshold level setting, a peak discriminator and a logic circuit to fulfill pile-up rejection, signal sampling, trigger generation, channel reset and the preamplifier and discriminators disabling functionalities. A Serial Peripherical Interface (SPI) is integrated in VEGA for loading and storing all configuration parameters in an internal register within few microseconds. The VEGA ASIC has been designed and manufactured in 0.35 µm CMOS mixed-signal technology in single and 32 channel versions with dimensions of 200 µm×500 µm per channel. A minimum intrinsic Equivalent Noise Charge (ENC) of 12 electrons r.m.s. at 3.6 µs peaking time and room temperature is measured and the linearity error is between −0.9% and +0.6% in the whole input energy range. The total power consumption is 481 µW and 420 µW per channel for the single and 32 channels version, respectively. A comparison with other ASICs for X-ray SDD’s shows that VEGA has a suitable low noise and offers high functionality as ADC-ready signal processing but at a power consumption that is a factor of four lower than other similar existing ASICs

  11. CMS Silicon Strip Tracker Monitoring

    CERN Document Server

    Mersi, Stefano

    2010-01-01

    The CMS Silicon Strip Tracker is the largest detector of its kind ever operated, with a silicon surface area of about 200 m$^2$ of silicon surface. The Silicon Strip Tracker it is the sub-detector with the highest number of detector modules within the CMS experiment. Given the complexity of the device, a variety of tools were developed and are used to determine the status of the detector in real time and allow for data qualification and corrective actions when needed. In this paper we describe the monitoring techniques that are used to safely operate the detector and assess the state of its calibration.

  12. Single crystalline mesoporous silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Hochbaum, Allon; Dargas, Daniel; Hwang, Yun Jeong; Yang, Peidong

    2009-08-18

    Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. The photoluminescence of these nanowires suggest they are composed of crystalline silicon with small enough dimensions such that these arrays may be useful as photocatalytic substrates or active components of nanoscale optoelectronic devices. A better understanding of this electroless route to mesoporous silicon could lead to facile and general syntheses of different narrow bandgap semiconductor nanostructures for various applications.

  13. Segmented scintillation detectors with silicon photomultiplier readout for measuring antiproton annihilations

    CERN Document Server

    Sótér, A; Kobayashi, T; Barna, D; Horvath, D; Hori, M

    2014-01-01

    The Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) experiment at the Antiproton Decelerator (AD) facility of CERN constructed segmented scintillators to detect and track the charged pions which emerge from antiproton annihilations in a future superconducting radiofrequency Paul trap for antiprotons. A system of 541 cast and extruded scintillator bars were arranged in 11 detector modules which provided a spatial resolution of 17 mm. Green wavelength-shifting fibers were embedded in the scintillators, and read out by silicon photomultipliers which had a sensitive area of 1 x 1 mm^2. The photoelectron yields of various scintillator configurations were measured using a negative pion beam of momentum p ~ 1 GeV/c. Various fibers and silicon photomultipliers, fiber end terminations, and couplings between the fibers and scintillators were compared. The detectors were also tested using the antiproton beam of the AD. Nonlinear effects due to the saturation of the silicon photomultiplier were seen a...

  14. Thermal management and mechanical structures for silicon detector systems

    International Nuclear Information System (INIS)

    Due to the size of current silicon tracking systems system aspects have become a major design driver. This article discusses requirements for the engineering of the mechanical structures and thermal management of such systems and reviews solutions developed to satisfy them. Modern materials and fabrication techniques have been instrumental in constructing these devices and will be discussed here. Finally, this paper will describe current and potential future developments in the engineering of silicon tracking systems which will shape the silicon tracking systems of the future

  15. Silicon Ingot Casting - Heat Exchanger Method (HEM). Multi-Wire Slicing - Fixed Abrasive Slicing Technique (Fast). Phase 4 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-Cost Solar Array Project

    Science.gov (United States)

    Schmid, F.

    1981-01-01

    The crystallinity of large HEM silicon ingots as a function of heat flow conditions is investigated. A balanced heat flow at the bottom of the ingot restricts spurious nucleation to the edge of the melted-back seed in contact with the crucible. Homogeneous resistivity distribution over all the ingot has been achieved. The positioning of diamonds electroplated on wirepacks used to slice silicon crystals is considered. The electroplating of diamonds on only the cutting edge is described and the improved slicing performance of these wires evaluated. An economic analysis of value added costs of HEM ingot casting and band saw sectioning indicates the projected add on cost of HEM is well below the 1986 allocation.

  16. Influence of tracks densities in solid state nuclear track detectors

    International Nuclear Information System (INIS)

    When Solid State Nuclear Track Detectors (SSNTD) is employed to measure nuclear tracks produced mainly by fission fragments and alpha particles, it is considered that the tracks observation work is performed under an efficiency, ε0, which is independent of the track density (number of tracks/area unit). There are not published results or experimental data supporting such an assumption. In this work the dependence of ε0 with track density is studied basing on experimental data. To perform this, pieces of CR-39 cut from a sole 'mother sheet' were coupled to thin uranium films for different exposition times and the resulting ratios between track density and exposition time were compared. Our results indicate that ε0 is constant for track densities between 103 and 105 cm-2. At our etching conditions track overlapping makes impossible the counting for densities around 1.7 x 105 cm-2. For track densities less than 103 cm-2, ε0 , was not observed to be constant. (authors). 4 refs., 2 figs

  17. Results from a hybrid silicon pixel telescope tested in a heavy ion experiment at the Cern Omega Spectrometer

    International Nuclear Information System (INIS)

    A telescope made of three OMEGA-ION hybrid silicon pixel detectors has been successfully tested in the heavy ion experiment WA94. Each plane consisted of a single detector with 1006 active pixels (500 μm x 75 μm), each one being bump-bonded to the read-out chip, and arranged in 16 columns and 63 rows respectively. With a sensitive area as small as 8000x4725 μm2 several million events with at least one track originating from sulphur-sulphur interactions have been recorded in a few hours. Results on target reconstruction, tracking accuracy and efficiency are presented. (orig.)

  18. Evaluation of two 'fast' software tools for the measurement of left ventricular volumes in retrospectively ECG-gated multidetector CT of the heart: biplane area-length method and 'shape tracking' method

    International Nuclear Information System (INIS)

    Purpose: Evaluation of 2 'fast' software tools, a biplane area-length method, and a new automatic 'shape tracking' method, for the calculation of left ventricle volumes (end-diastolic volume EDV, end-systolic volume ESV, stroke volume SV) and ejection fraction (EF) in retrospectively ECG-gated multidetector computed tomography. Materials and Methods: 60 contrast-enhanced cardiac CT datasets (16 x 0.75 mm collimation, normal dose: 120 - 140 kV, 400 - 500 mAseff [n = 44], low dose 120 kV, 100 mAseff [n = 16]) were acquired from eight intubated healthy pigs on different days. Images were reconstructed with a slice thickness and increment of 2 mm every 10 % of the cardiac cycle. The LV function was evaluated via the common short axis method as the reference method, the biplane area-length method, and the automatic 'shape tracking' method. In the latter a three-dimensional triangulated deformable surface model was used to segment the endocardial border of the left ventricle and to track its motion through the cardiac phases. The results were compared using the Bland-Altman-plot, the correlation coefficient, and the Wilcoxon test. Results: All 60 data sets could be evaluated with all three methods. Good correlations were found for left ventricular functional parameters for all data sets, the normal dose (ND), and low dose (LD) data sets between 0.65 and 0.89 for the 'shape tracking' method and between 0.7 and 0.87 for the area-length method. The 'shape tracking' method showed a mean overestimation of the EDV of 3.1 (LD, p 0.38) to 4.3 ml (ND, p < 0.05), the SV of 4.0 (LD, p = 0.08) to 4.9 ml (ND, p < 0.05) and the EF of 1.3 (LD, p = 0.16) to 2.0 % (ND, p < 0.05). The EDV was underestimated between 0.3 (LD, p = 0.7) and 1.1 ml (ND, p = 0.08). The area-length method showed an overestimation of the EDV (6.6 to 6.7 ml [p < 0.05]), the SV (5.9 to 8.4 ml [p < 0.05]), the EF (1.2 to 3.0 % [p < 0.05]) and the normal dose ESV (0.6 ml [p = 0.74]). The low dose ESV was

  19. Real time tracking in liver SBRT: comparison of CyberKnife and Vero by planning structure-based γ-evaluation and dose-area-histograms.

    Science.gov (United States)

    Sothmann, T; Blanck, O; Poels, K; Werner, R; Gauer, T

    2016-02-21

    The purpose of this study was to evaluate and compare two clinical tracking systems for radiosurgery with regard to their dosimetric and geometrical accuracy in liver SBRT: the robot-based CyberKnife and the gimbal-based Vero. Both systems perform real-time tumour tracking by correlating internal tumour and external surrogate motion. CyberKnife treatment plans were delivered to a high resolution 2D detector array mounted on a 4D motion platform, with the platform simulating (a) tumour motion trajectories extracted from the corresponding CyberKnife predictor log files and (b) the tumour motion trajectories with superimposed baseline-drift. Static reference and tracked dose measurements were compared and dosimetric as well as geometrical uncertainties analyzed by a planning structure-based evaluation. For (a), γ-passing rates inside the CTV (γ-criteria of 1% / 1 mm) ranged from 95% to 100% (CyberKnife) and 98% to 100% (Vero). However, dosimetric accuracy decreases in the presence of the baseline-drift. γ-passing rates for (b) ranged from 26% to 92% and 94% to 99%, respectively; i.e. the effect was more pronounced for CyberKnife. In contrast, the Vero system led to maximum dose deviations in the OAR between  +1.5 Gy to +6.0 Gy (CyberKnife: +0.5 Gy to +3.5 Gy). Potential dose shifts were interpreted as motion-induced geometrical tracking errors. Maximum observed shift ranges were  -1.0 mm to  +0.7 mm (lateral) /-0.6 mm to +0.1 mm (superior-inferior) for CyberKnife and  -0.8 mm to +0.2 mm /-0.8 mm to +0.4 mm for Vero. These values illustrate that CyberKnife and Vero provide high precision tracking of regular breathing patterns. Even for the modified motion trajectory, the obtained dose distributions appear to be clinical acceptable with regard to literature QA γ-criteria of 3% / 3 mm. PMID:26836488

  20. Real time tracking in liver SBRT: comparison of CyberKnife and Vero by planning structure-based γ-evaluation and dose-area-histograms

    Science.gov (United States)

    Sothmann, T.; Blanck, O.; Poels, K.; Werner, R.; Gauer, T.

    2016-02-01

    The purpose of this study was to evaluate and compare two clinical tracking systems for radiosurgery with regard to their dosimetric and geometrical accuracy in liver SBRT: the robot-based CyberKnife and the gimbal-based Vero. Both systems perform real-time tumour tracking by correlating internal tumour and external surrogate motion. CyberKnife treatment plans were delivered to a high resolution 2D detector array mounted on a 4D motion platform, with the platform simulating (a) tumour motion trajectories extracted from the corresponding CyberKnife predictor log files and (b) the tumour motion trajectories with superimposed baseline-drift. Static reference and tracked dose measurements were compared and dosimetric as well as geometrical uncertainties analyzed by a planning structure-based evaluation. For (a), γ-passing rates inside the CTV (γ-criteria of 1% / 1 mm) ranged from 95% to 100% (CyberKnife) and 98% to 100% (Vero). However, dosimetric accuracy decreases in the presence of the baseline-drift. γ-passing rates for (b) ranged from 26% to 92% and 94% to 99%, respectively; i.e. the effect was more pronounced for CyberKnife. In contrast, the Vero system led to maximum dose deviations in the OAR between  +1.5 Gy to  +6.0 Gy (CyberKnife:  +0.5 Gy to  +3.5 Gy). Potential dose shifts were interpreted as motion-induced geometrical tracking errors. Maximum observed shift ranges were  -1.0 mm to  +0.7 mm (lateral) /-0.6 mm to  +0.1 mm (superior-inferior) for CyberKnife and  -0.8 mm to  +0.2 mm /-0.8 mm to  +0.4 mm for Vero. These values illustrate that CyberKnife and Vero provide high precision tracking of regular breathing patterns. Even for the modified motion trajectory, the obtained dose distributions appear to be clinical acceptable with regard to literature QA γ-criteria of 3% / 3 mm.

  1. Analysis and correction of track overlapping on nuclear track detectors (SSNTD)

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, D.; Sajo B, L.; Barros, H.; Avila, Y. [Universidad Simon Bolivar, P. O. 89000 Caracas (Venezuela, Bolivarian Republic of); Fusella, E. [Instituto de Estudios Avanzados, Apartado 17606, Caracas 1015-A (Venezuela, Bolivarian Republic of)

    2011-02-15

    The problem of nuclear track overlapping is addressed assuming the stochastic character of charged particle registry and the fact that even monoenergetic beam perpendicularly impacting on detector surface will show a distribution for track radius values. Asymmetric distributions of overlapping tracks were obtained for very low or very high simulated track quantities, while for intermediate values the distributions were well described by Gaussian s. A model for the track overlapping process was developed, considering the dependence of the quantity of non overlapping tracks on the number of simulated tracks by a second order homogeneous differential lineal equation. Its solution contains only one free parameter that is related to track geometry and field view area. By successive approximation, the number of total induced tracks (which is proportional to particle fluence) is determined from the knowledge of the amount of non overlapping tracks, dimensions of the field view and average track radius. (Author)

  2. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Silicon Dioxide Coating Deposited by PDPs on PET Films and Influence on Oxygen Transmission Rate

    Science.gov (United States)

    Sun, Yun-Jin; Fu, Ya-Bo; Chen, Qiang; Zhang, Chun-Mei; Sang, Li-Jun; Zhang, Yue-Fei

    2008-05-01

    A silicon dioxide film is deposited on the polyethyleneterephtalate (PET) by a penning discharge plasma source at ambient temperature in a high vacuum chamber. Hexamethyldisiloxane and oxygen are adopted as precursor and reactive reagent to grow a nano-scale silicon dioxide layer on polymer surfaces. For the chemical structure analysis x-ray photoelectron spectroscopy is performed to demonstrate the content of Si, O and C elements. It is noticed that a higher silicon concentration is contained if Ar plasma is used for pretreatment. X-ray diffraction analysis shows that a micro-crystal silicon dioxide is formed by peak patterns at 25.84° and 21.8°. The barrier properties examined by oxygen transmission rate show that the permeation parameter of the 12-μm-thick PET film drastically decreases from 135cc/m2 per day for the control one to 0.713cc/m2 per day for the as-deposited one after Ar plasma treatment. The surface morphology related to the barrier properties of SiOx-coated polymers os also investigated by scanning electron microscopy and atomic force microscopy.

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

    Czech Academy of Sciences Publication Activity Database

    Unno, Y.; Edwards, S.O.; Pyatt, S.; Böhm, Jan; Mikeštíková, Marcela

    2014-01-01

    Roč. 765, Nov (2014), s. 80-90. ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : silicon strip * n + -in-p * P-type * Radiation-tolerant * HL-LHC * PTP Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.216, year: 2014

  4. Superconvergent tracking

    International Nuclear Information System (INIS)

    In this paper we develop a new technique (superconvergent tracking) for tracking particles through a circular accelerator or a transport line with nonlinear elements. We use the superconvergent perturbation theory of Kolmogorov to solve the Hamilton-Jacobi equation (approximately) over a finite time interval. This transformation defines a map from the initial conditions to the state of the system at some later time. This technique can be iterated to examine long-term stability in betatron phase space in a circular accelerator, or it can be used to calculate the trajectory in betatron phase space of particles in a transport line. We verify the algorithm with two test cases in one degree of freedom and then develop the technique to track the two transverse degrees of freedom in a general accelerator lattice with sextupoles. As an example we track a section of the Superconducting Super Collider (SSC) arcs with and without sextupole errors in the bending magnets. (author) 14 refs., 15 figs., 1 tab

  5. Advanced Alignment of the ATLAS Tracking System

    CERN Document Server

    Butti, P; The ATLAS collaboration

    2014-01-01

    In order to reconstruct the trajectories of charged particles, the ATLAS experiment exploits a tracking system built using different technologies, planar silicon modules or microstrips (PIX and SCT detectors) and gaseous drift tubes (TRT), all embedded in a 2T solenoidal magnetic field. Misalignments and deformations of the active detector elements deteriorate the track reconstruction resolution and lead to systematic biases on the measured track parameters. The alignment procedures exploits various advanced tools and techniques in order to determine for module positions and correct for deformations. For the LHC Run II, the system is being upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL).

  6. Silicon Ingot Casting - Heat Exchanger Method Multi-wire Slicing - Fixed Abrasive Slicing Technique. Phase 3 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-cost Solar Array Project

    Science.gov (United States)

    Schmid, F.; Khattak, C. P.

    1979-01-01

    Several 20 cm diameter silicon ingots, up to 6.3 kg. were cast with good crystallinity. The graphite heat zone can be purified by heating it to high temperatures in vacuum. This is important in reducing costs and purification of large parts. Electroplated wires with 45 um synthetic diamonds and 30 um natural diamonds showed good cutting efficiency and lifetime. During slicing of a 10 cm x 10 cm workpiece, jerky motion occurred in the feed and rocking mechanisms. This problem is corrected and modifications were made to reduce the weight of the bladeheat by 50%.

  7. The STAR Tracking Upgrade

    International Nuclear Information System (INIS)

    The STAR collaboration is preparing a tracking detector upgrade, the Heavy Flavor Tracker (HFT) and the Forward GEM Tracker (FGT) to further investigate fundamental properties of the new state of strongly interacting matter produced in relativistic-heavy ion collisions at RHIC and to provide fundamental studies of the proton spin structure and dynamics in high-energy polarized proton-proton collisions at RHIC. The HFT is based on a novel two-layer CMOS active-pixel sensor detector together with a conventional two-layer silicon-strip/silicon-pad detector. The FGT upgrade will consist of six triple-GEM detectors with two dimensional readout arranged in disks along the beam axis. The FGT project has completed an extensive R and D program of industrially produced GEM foils at Tech-Etch Inc. in comparison to GEM foils produced at CERN based on optical measurements, test beam and 55Fe source measurements of a triple-GEM prototype detector using 10 x 10 cm2 GEM foils. The FGT project requires large GEM foils which are currently being tested. The HFT and FGT design, the status of full prototype tests along with the HFT and FGT construction and the installation schedule will be presented. (author)

  8. Porous silicon carbide (SIC) semiconductor device

    Science.gov (United States)

    Shor, Joseph S. (Inventor); Kurtz, Anthony D. (Inventor)

    1996-01-01

    Porous silicon carbide is fabricated according to techniques which result in a significant portion of nanocrystallites within the material in a sub 10 nanometer regime. There is described techniques for passivating porous silicon carbide which result in the fabrication of optoelectronic devices which exhibit brighter blue luminescence and exhibit improved qualities. Based on certain of the techniques described porous silicon carbide is used as a sacrificial layer for the patterning of silicon carbide. Porous silicon carbide is then removed from the bulk substrate by oxidation and other methods. The techniques described employ a two-step process which is used to pattern bulk silicon carbide where selected areas of the wafer are then made porous and then the porous layer is subsequently removed. The process to form porous silicon carbide exhibits dopant selectivity and a two-step etching procedure is implemented for silicon carbide multilayers.

  9. Floating Silicon Method

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  10. Binomial distribution of Poisson statistics and tracks overlapping probability to estimate total tracks count with low uncertainty

    International Nuclear Information System (INIS)

    In the solid state nuclear track detectors of chemically etched type, nuclear tracks with center-to-center neighborhood of distance shorter than two times the radius of tracks will emerge as overlapping tracks. Track overlapping in this type of detectors causes tracks count losses and it becomes rather severe in high track densities. Therefore, tracks counting in this condition should include a correction factor for count losses of different tracks overlapping orders since a number of overlapping tracks may be counted as one track. Another aspect of the problem is the cases where imaging the whole area of the detector and counting all tracks are not possible. In these conditions a statistical generalization method is desired to be applicable in counting a segmented area of the detector and the results can be generalized to the whole surface of the detector. Also there is a challenge in counting the tracks in densely overlapped tracks because not sufficient geometrical or contextual information are available. It this paper we present a statistical counting method which gives the user a relation between the tracks overlapping probabilities on a segmented area of the detector surface and the total number of tracks. To apply the proposed method one can estimate the total number of tracks on a solid state detector of arbitrary shape and dimensions by approximating the tracks averaged area, whole detector surface area and some orders of tracks overlapping probabilities. It will be shown that this method is applicable in high and ultra high density tracks images and the count loss error can be enervated using a statistical generalization approach. - Highlights: • A correction factor for count losses of different tracks overlapping orders. • For the cases imaging the whole area of the detector is not possible. • Presenting a statistical generalization method for segmented areas. • Giving a relation between the tracks overlapping probabilities and the total tracks

  11. The CDF Silicon Vertex Trigger

    International Nuclear Information System (INIS)

    The Collider Detector at Fermilab (CDF) experiment's Silicon Vertex Trigger (SVT) is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a 15 μs pipeline. SVT's 35 μm impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common interboard data link, and a universal 'Merger' board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs

  12. The CDF Silicon Vertex Trigger

    Energy Technology Data Exchange (ETDEWEB)

    Ashmanskas, Bill E-mail: wja@hep.anl.gov; Barchiesi, A.; Bardi, A.; Bari, M.; Baumgart, M.; Belforte, S.; Berryhill, J.; Bogdan, M.; Carosi, R.; Cerri, A.; Chlachidze, G.; Culbertson, R.; Dell' Orso, M.; Donati, S.; Fiori, I.; Frisch, H.; Galeotti, S.; Giannetti, P.; Glagolev, V.; Leger, A.; Liu, Y.; Maruyama, T.; Meschi, E.; Moneta, L.; Morsani, F.; Nakaya, T.; Punzi, G.; Rescigno, M.; Ristori, L.; Sanders, H.; Sarkar, S.; Semenov, A.; Shochet, M.; Speer, T.; Spinella, F.; Vataga, H.; Wu, X.; Yang, U.K.; Zanello, L.; Zanetti, A.M

    2004-02-01

    The Collider Detector at Fermilab (CDF) experiment's Silicon Vertex Trigger (SVT) is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a 15 {mu}s pipeline. SVT's 35 {mu}m impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common interboard data link, and a universal 'Merger' board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.

  13. The CDF Silicon Vertex Trigger

    CERN Document Server

    Barchiesi, A; Bari, M; Baumgart, M D; Belforte, S; Berryhill, J W; Bogdan, M; Carosi, R; Cerri, A; Chlachidze, G; Culbertson, R; Dell'Orso, Mauro; Donati, S; Fiori, I; Frisch, H; Galeotti, S; Giannetti, P; Glagolev, V; Léger, A; Liu, Y; Maruyama, T; Meschi, E; Moneta, L; Morsani, F; Nakaya, T; Punzi, G; Rescigno, M; Ristori, L; Sanders, H; Sarkar, S; Semenov, A; Shochet, M J; Speer, T; Spinella, F; Vataga, H; Wu, X; Yang, U K; Zanello, L; Zanetti, A M

    2004-01-01

    The CDF experiment's Silicon Vertex Trigger is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a 15 microsecond pipeline. SVT's 35 micron impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common inter-board data link, and a universal "Merger" board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.

  14. Overview of Silicon Detectors in STAR: Present and Future

    Energy Technology Data Exchange (ETDEWEB)

    Kabana, Sonia [Laboratoire de Physique Subatomique et des technologies associees, SUBATECH, Ecole des Mines, 4 rue Alfred Kastler, 44307 Nantes cedex 3 (France); Collaboration: The SVT, SSD and HFT detector groups of the STAR experiment at RHIC

    2011-12-13

    The STAR experiment at RHIC aims to study the QCD phase transition and the origin of the spin of the proton. Its main detector for charged particle track reconstruction is a Time Projection Chamber, which has been supplemented with a silicon detector involving two different technologies, in particular double-sided silicon strip and silicon drift technology. STAR is preparing now for a new Silicon Vertex Detector, using double-sided silicon strip, single-sided silicon strip-pads, and CMOS monolithic active pixel sensors technology, planned to take data in 2014. We give an overview of the design, calibration and performances of the silicon detectors used by the STAR experiment in the past and the expected performances of the future silicon detector upgrade.

  15. Overview of Silicon Detectors in STAR: Present and Future

    International Nuclear Information System (INIS)

    The STAR experiment at RHIC aims to study the QCD phase transition and the origin of the spin of the proton. Its main detector for charged particle track reconstruction is a Time Projection Chamber, which has been supplemented with a silicon detector involving two different technologies, in particular double-sided silicon strip and silicon drift technology. STAR is preparing now for a new Silicon Vertex Detector, using double-sided silicon strip, single-sided silicon strip-pads, and CMOS monolithic active pixel sensors technology, planned to take data in 2014. We give an overview of the design, calibration and performances of the silicon detectors used by the STAR experiment in the past and the expected performances of the future silicon detector upgrade.

  16. Doppler tracking

    Science.gov (United States)

    Thomas, Christopher Jacob

    This study addresses the development of a methodology using the Doppler Effect for high-resolution, short-range tracking of small projectiles and vehicles. Minimal impact on the design of the moving object is achieved by incorporating only a transmitter in it and using ground stations for all other components. This is particularly useful for tracking objects such as sports balls that have configurations and materials that are not conducive to housing onboard instrumentation. The methodology developed here uses four or more receivers to monitor a constant frequency signal emitted by the object. Efficient and accurate schemes for filtering the raw signals, determining the instantaneous frequencies, time synching the frequencies from each receiver, smoothing the synced frequencies, determining the relative velocity and radius of the object and solving the nonlinear system of equations for object position in three dimensions as a function of time are developed and described here.

  17. Integration of an amorphous silicon passive pixel sensor array with a lateral amorphous selenium detector for large area indirect conversion x-ray imaging applications

    Science.gov (United States)

    Wang, Kai; Yazdandoost, Mohammad Y.; Keshavarzi, Rasoul; Shin, Kyung-Wook; Hristovski, Christos; Abbaszadeh, Shiva; Chen, Feng; Majid, Shaikh Hasibul; Karim, Karim S.

    2011-03-01

    Previously, we reported on a single-pixel detector based on a lateral a-Se metal-semiconductor-metal structure, intended for indirect conversion X-ray imaging. This work is the continuous effort leading to the first prototype of an indirect conversion X-ray imaging sensor array utilizing lateral amorphous selenium. To replace a structurally-sophisticated vertical multilayer amorphous silicon photodiode, a lateral a-Se MSM photodetector is employed which can be easily integrated with an amorphous silicon thin film transistor passive pixel sensor array. In this work, both 2×2 macro-pixel and 32×32 micro-pixel arrays were fabricated and tested along with discussion of the results.

  18. Tracking Porters

    DEFF Research Database (Denmark)

    Bruun, Maja Hojer; Krause-Jensen, Jakob; Nielsen, Margit Saltofte

    2015-01-01

    Anthropology attempts to gain insight into people's experiential life-worlds through long-term fieldwork. The quality of anthropological knowledge production, however, does not depend solely on the duration of the stay in the field, but also on a particular way of seeing social situations. The...... two weeks the students followed the work of a group of porters. Drawing on anthropological concepts and research strategies the students gained crucial insights about the potential effects of using tracking technologies in the hospital....

  19. Evaluation of the bulk and strip characteristics of large area n-in-p silicon sensors intended for a very high radiation environment

    Czech Academy of Sciences Publication Activity Database

    Böhm, Jan; Mikeštíková, Marcela; Affolder, A.A.; Allport, P.P.; Bates, R.; Betancourt, C.; Brown, H.; Buttar, C.; Carter, J. R.; Casse, G.

    2011-01-01

    Roč. 636, č. 1 (2011), "S104"-"S110". ISSN 0168-9002 R&D Projects: GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : silicon * micro-strip * ATLAS ID upgrade * SLHC * leakage current * depletion voltage * electrical characteristics * coupling capacitance Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.207, year: 2011 http://dx.doi.org/10.1016/j.nima.2010.04.093

  20. Large-Area Crystalline Silicon Solar Cell Using Novel Antireflective Nanoabsorber Texturing Surface by Multihollow Cathode Plasma System and Spin-On Doping

    OpenAIRE

    Utpal Gangopadhyay; Sukhendu Jana; Sayan Das

    2013-01-01

    We present 11.7% efficient p-type crystalline silicon solar cells with a nanoscale textured surface and no dielectric antireflection coating. We propose nanocrystalline-like textured surface consisting of nanocrystalline columnar structures of diameters from 50 to 100 nm and depth of about 500 nm formed by reactive-ion etching (RIE) in multihollow cathode system. This novel nano textured surface acts as an antireflective absorbing surface of c-Si abbreviate as ARNAB (antireflective nanoabsorb...

  1. The LHCb Silicon Tracker Project

    Energy Technology Data Exchange (ETDEWEB)

    Agari, M. [Max Planck Institute for Nuclear Physics (Germany); Bauer, C. [Max Planck Institute for Nuclear Physics (Germany); Baumeister, D. [Max Planck Institute for Nuclear Physics (Germany); Blouw, J. [Max Planck Institute for Nuclear Physics (Germany)]. E-mail: Johan.Blouw@mpi-hd.mpg.de; Hofmann, W. [Max Planck Institute for Nuclear Physics (Germany); Knoepfle, K.T. [Max Planck Institute for Nuclear Physics (Germany); Loechner, S. [Max Planck Institute for Nuclear Physics (Germany); Schmelling, M. [Max Planck Institute for Nuclear Physics (Germany); Pugatch, V. [Kiev Institute for Nuclear Research (Ukraine); Bay, A. [Laboratoire de Physique des Hautes Energies, Ecole Polytechnique de Lausanne (France); Carron, B. [Laboratoire de Physique des Hautes Energies, Ecole Polytechnique de Lausanne (France); Frei, R. [Laboratoire de Physique des Hautes Energies, Ecole Polytechnique de Lausanne (France); Jiminez-Otero, S. [Laboratoire de Physique des Hautes Energies, Ecole Polytechnique de Lausanne (France); Tran, M.-T. [Laboratoire de Physique des Hautes Energies, Ecole Polytechnique de Lausanne (France); Voss, H. [Laboratoire de Physique des Hautes Energies, Ecole Polytechnique de Lausanne (France); Adeva, B. [Universidad de Santiago de Compostela (Spain); Esperante, D. [Universidad de Santiago de Compostela (Spain); Lois, C. [Universidad de Santiago de Compostela (Spain); Vasquez, P. [Universidad de Santiago de Compostela (Spain); Bernhard, R.P. [Physik-Insitut Universitaet Zuerich (Switzerland); Bernet, R. [Physik-Insitut Universitaet Zuerich (Switzerland); Ermoline, Y. [Physik-Insitut Universitaet Zuerich (Switzerland); Gassner, J. [Physik-Insitut Universitaet Zuerich (Switzerland); Koestner, S. [Physik-Insitut Universitaet Zuerich (Switzerland); Lehner, F.; Needham, M.; Siegler, M.; Steinkamp, O.; Straumann, U.; Vollhardt, A.; Volyanskyy, D. [Physik-Insitut Universitaet Zuerich (Switzerland)

    2006-01-15

    Two silicon strip detectors, the Trigger Tracker(TT) and the Inner Tracker(Italy) will be constructed for the LHCb experiment. Transverse momentum information extracted from the TT will be used in the Level 1 trigger. The IT is part of the main tracking system behind the magnet. Both silicon detectors will be read out using a custom-developed chip by the ASIC lab in Heidelberg. The signal-over-noise behavior and performance of various geometrical designs of the silicon sensors, in conjunction with the Beetle read-out chip, have been extensively studied in test beam experiments. Results from those experiments are presented, and have been used in the final choice of sensor geometry.

  2. The LHCb Silicon Tracker Project

    International Nuclear Information System (INIS)

    Two silicon strip detectors, the Trigger Tracker(TT) and the Inner Tracker(Italy) will be constructed for the LHCb experiment. Transverse momentum information extracted from the TT will be used in the Level 1 trigger. The IT is part of the main tracking system behind the magnet. Both silicon detectors will be read out using a custom-developed chip by the ASIC lab in Heidelberg. The signal-over-noise behavior and performance of various geometrical designs of the silicon sensors, in conjunction with the Beetle read-out chip, have been extensively studied in test beam experiments. Results from those experiments are presented, and have been used in the final choice of sensor geometry

  3. Development of Tandem Amorphous/Microcrystalline Silicon Thin-Film Large-Area See-Through Color Solar Panels with Reflective Layer and 4-Step Laser Scribing for Building-Integrated Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film large-area see-through color solar modules were successfully designed and developed for building-integrated photovoltaic applications. Novel and key technologies of reflective layers and 4-step laser scribing were researched, developed, and introduced into the production line to produce solar panels with various colors, such as purple, dark blue, light blue, silver, golden, orange, red wine, and coffee. The highest module power is 105 W and the highest visible light transmittance is near 20%.

  4. Environmental Public Health Tracking: Health and Environment Linked for Information Exchange-Atlanta (HEXIX-Atlanta: A cooperative Program Between CDC and NASA for Development of an Environmental Public Health Tracking Network in the Atlanta Metropolitan Area

    Science.gov (United States)

    Quattrochi, Dale A.; Niskar, Amanda Sue

    2005-01-01

    The Centers for Disease Control and Prevention (CDC) is coordinating HELIX- Atlanta to provide information regarding the five-county Metropolitan Atlanta Area (Clayton, Cobb, DeKalb, Fulton, and Gwinett) via a network of integrated environmental monitoring and public health data systems so that all sectors can take action to prevent and control environmentally related health effects. The HELIX-Atlanta Network is a tool to access interoperable information systems with optional information technology linkage functionality driven by scientific rationale. HELIX-Atlanta is a collaborative effort with local, state, federal, and academic partners, including the NASA Marshall Space Flight Center. The HELIX-Atlanta Partners identified the following HELIX-Atlanta initial focus areas: childhood lead poisoning, short-latency cancers, developmental disabilities, birth defects, vital records, respiratory health, age of housing, remote sensing data, and environmental monitoring, HELIX-Atlanta Partners identified and evaluated information systems containing information on the above focus areas. The information system evaluations resulted in recommendations for what resources would be needed to interoperate selected information systems in compliance with the CDC Public Health Information Network (PHIN). This presentation will discuss the collaborative process of building a network that links health and environment data for information exchange, including NASA remote sensing data, for use in HELIX-Atlanta.

  5. Material Properties of Laser-Welded Thin Silicon Foils

    OpenAIRE

    Brabec, C.J.; Auer, R.; A. Bochmann; Christiansen, S.; Schmidt, M.; K. Cvecek; Voigt, M.; Hessmann, M. T.; Kunz, T.

    2013-01-01

    An extended monocrystalline silicon base foil offers a great opportunity to combine low-cost production with high efficiency silicon solar cells on a large scale. By overcoming the area restriction of ingot-based monocrystalline silicon wafer production, costs could be decreased to thin film solar cell range. The extended monocrystalline silicon base foil consists of several individual thin silicon wafers which are welded together. A comparison of three different approaches to weld 50 μm thin...

  6. Dual Tracking Method for Real Time Object Tracking using Moving Camera

    Directory of Open Access Journals (Sweden)

    Shyam Lal

    2013-04-01

    Full Text Available This study presents dual tracking method for real time object tracking using a moving camera. A real time object tracking using self aligning servo mechanism with webcam, dual tracking and effective localization of object is presented. The proposed dual tracking method works in two phases: In first phase tracking is done by joint color texture histogram with mean shift and in second phase tracking is done by servo setup. The proposed dual tracking method enjoys the benefit of double tracking feature, not only tracking but also to find out the coordinates of the tracking object which is of particular interest. The coordinates of a moving object enable us to estimates the real time location of the object which is helpful in surveillance and shooting purposes of suspected person in security area. The tracking of some specific objects in real life is of particular interest. Due to its enhanced automation the proposed dual tracking method can be applied in public security, surveillance, robotics and traffic control etc. The experimental results demonstrate that the proposed dual tracking method improves greatly the tracking area with accuracy and efficiency and also successfully find the coordinates of moving object.

  7. Report of the Central Tracking Group

    International Nuclear Information System (INIS)

    Issues involved in building a realistic central tracking system for a general-purpose 4π detector for the SSC are addressed. Such a central tracking system must be capable of running at the full design luminosity of 1033 cm-2s-1. Momentum measurement was required in a general-purpose 4π detector. Limitations on charged particle tracking detectors at the SSC imposed by rates and radiation damage are reviewed. Cell occupancy is the dominant constraint, which led us to the conclusion that only small cells, either wires or straw tubes, are suitable for a central tracking system at the SSC. Mechanical problems involved in building a central tracking system of either wires or straw tubes were studied, and our conclusion was that it is possible to build such a large central tracking system. Of course, a great deal of research and development is required. We also considered central tracking systems made of scintillating fibers or silicon microstrips, but our conclusion was that neither is a realistic candidate given the current state of technology. We began to work on computer simulation of a realistic central tracking system. Events from interesting physics processes at the SSC will be complex and will be further complicated by hits from out-of-time bunch crossings and multiple interactions within the same bunch crossing. Detailed computer simulations are needed to demonstrate that the pattern recognition and tracking problems can be solved

  8. Radiation hard silicon detectors - developments by the RD48 (ROSE) collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Lindstroem, G. E-mail: gunnar.lindstroem@desy.de; Ahmed, M.; Albergo, S.; Allport, P.; Anderson, D.; Andricek, L.; Angarano, M.M.; Augelli, V.; Bacchetta, N.; Bartalini, P.; Bates, R.; Biggeri, U.; Bilei, G.M.; Bisello, D.; Boemi, D.; Borchi, E.; Botila, T.; Brodbeck, T.J.; Bruzzi, M.; Budzynski, T.; Burger, P.; Campabadal, F.; Casse, G.; Catacchini, E.; Chilingarov, A.; Ciampolini, P.; Cindro, V.; Costa, M.J.; Creanza, D.; Clauws, P.; Da Via, C.; Davies, G.; De Boer, W.; Dell' Orso, R.; De Palma, M.; Dezillie, B.; Eremin, V.; Evrard, O.; Fallica, G.; Fanourakis, G.; Feick, H.; Focardi, E.; Fonseca, L.; Fretwurst, E.; Fuster, J.; Gabathuler, K.; Glaser, M.; Grabiec, P.; Grigoriev, E.; Hall, G.; Hanlon, M.; Hauler, F.; Heising, S.; Holmes-Siedle, A.; Horisberger, R.; Hughes, G.; Huhtinen, M.; Ilyashenko, I.; Ivanov, A.; Jones, B.K.; Jungermann, L.; Kaminsky, A.; Kohout, Z.; Kramberger, G.; Kuhnke, M.; Kwan, S.; Lemeilleur, F.; Leroy, C.; Letheren, M.; Li, Z.; Ligonzo, T.; Linhart, V.; Litovchenko, P.; Loukas, D.; Lozano, M.; Luczynski, Z.; Lutz, G.; MacEvoy, B.; Manolopoulos, S.; Markou, A.; Martinez, C.; Messineo, A.; Mikuz, M.; Moll, M.; Nossarzewska, E.; Ottaviani, G.; Oshea, V.; Parrini, G.; Passeri, D.; Petre, D.; Pickford, A.; Pintilie, I.; Pintilie, L.; Pospisil, S.; Potenza, R.; Raine, C.; Rafi, J.M.; Ratoff, P.N.; Richter, R.H.; Riedler, P.; Roe, S.; Roy, P.; Ruzin, A.; Ryazanov, A.I.; Santocchia, A.; Schiavulli, L.; Sicho, P.; Siotis, I.; Sloan, T.; Slysz, W.; Smith, K.; Solanky, M.; Sopko, B.; Stolze, K.; Sundby Avset, B.; Svensson, B.; Tivarus, C.; Tonelli, G.; Tricomi, A.; Tzamarias, S.; Valvo, G.; Vasilescu, A.; Vayaki, A.; Verbitskaya, E.; Verdini, P.; Vrba, V.; Watts, S.; Weber, E.R.; Wegrzecki, M.; Wegrzecka, I.; Weilhammer, P.; Wheadon, R.; Wilburn, C.; Wilhelm, I.; Wunstorf, R.; Wuestenfeld, J.; Wyss, J.; Zankel, K.; Zabierowski, P.; Zontar, D

    2001-07-01

    The RD48 (ROSE) collaboration has succeeded to develop radiation hard silicon detectors, capable to withstand the harsh hadron fluences in the tracking areas of LHC experiments. In order to reach this objective, a defect engineering technique was employed resulting in the development of Oxygen enriched FZ silicon (DOFZ), ensuring the necessary O-enrichment of about 2x10{sup 17} O/cm{sup 3} in the normal detector processing. Systematic investigations have been carried out on various standard and oxygenated silicon diodes with neutron, proton and pion irradiation up to a fluence of 5x10{sup 14} cm{sup -2} (1 MeV neutron equivalent). Major focus is on the changes of the effective doping concentration (depletion voltage). Other aspects (reverse current, charge collection) are covered too and the appreciable benefits obtained with DOFZ silicon in radiation tolerance for charged hadrons are outlined. The results are reliably described by the 'Hamburg model': its application to LHC experimental conditions is shown, demonstrating the superiority of the defect engineered silicon. Microscopic aspects of damage effects are also discussed, including differences due to charged and neutral hadron irradiation.

  9. Radiation hard silicon detectors - developments by the RD48 (ROSE) collaboration

    International Nuclear Information System (INIS)

    The RD48 (ROSE) collaboration has succeeded to develop radiation hard silicon detectors, capable to withstand the harsh hadron fluences in the tracking areas of LHC experiments. In order to reach this objective, a defect engineering technique was employed resulting in the development of Oxygen enriched FZ silicon (DOFZ), ensuring the necessary O-enrichment of about 2x1017 O/cm3 in the normal detector processing. Systematic investigations have been carried out on various standard and oxygenated silicon diodes with neutron, proton and pion irradiation up to a fluence of 5x1014 cm-2 (1 MeV neutron equivalent). Major focus is on the changes of the effective doping concentration (depletion voltage). Other aspects (reverse current, charge collection) are covered too and the appreciable benefits obtained with DOFZ silicon in radiation tolerance for charged hadrons are outlined. The results are reliably described by the 'Hamburg model': its application to LHC experimental conditions is shown, demonstrating the superiority of the defect engineered silicon. Microscopic aspects of damage effects are also discussed, including differences due to charged and neutral hadron irradiation

  10. Single crystalline mesoporous silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Hochbaum, A.I.; Gargas, Daniel; Jeong Hwang, Yun; Yang, Peidong

    2009-08-04

    Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. These porous nanowires also retain the crystallographic orientation of the wafer from which they are etched. Electron microscopy and diffraction confirm their single-crystallinity and reveal the silicon surrounding the pores is as thin as several nanometers. Confocal fluorescence microscopy showed that the photoluminescence (PL) of these arrays emanate from the nanowires themselves, and their PL spectrum suggests that these arrays may be useful as photocatalytic substrates or active components of nanoscale optoelectronic devices.

  11. Development of large-area monolithically integrated silicon-film{trademark} photovoltaic modules. Final subcontract report, May 1, 1991--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B.; Rand, J.A.; Cotter, J.E. [AstroPower, Inc., Newark, DE (United States)

    1995-04-01

    The objective of this program is to develop Silicon Film{trademark} Product III into a low-cost, stable solar cell for large-scale terrestrial power applications. The Product III structure is a thin (<100 {mu}m) polycrystalline layer of silicon on a durable, insulating, ceramic substrate. The insulating substrate allows the silicon layer to be isolated and metallized to form a monolithically interconnected array of solar cells. High efficiency is achieved by the use of light trapping and passivated surfaces. This project focused on the development of five key technologies associated with the monolithic sub-module device structure: (1) development of the film deposition and growth processes; (2) development of the low-cost ceramic substrate; (3) development of a metallurgical barrier technology; (4) development of sub-element solar cell processing techniques; and (5) development of sub-module (isolation and interconnection) processes. This report covers the development approaches and results relating to these technologies. Significant progress has been made in the development of all of the related technologies. This is evidenced by the fabrication of a working 12.0 cm{sup 2} prototype sub-module consisting of 7 elements and testing with an open circuit voltage of 3.9 volts, a short circuit current of 35.2 mA and a fill factor of 63% and an overall efficiency of 7.3%. Another significant result achieved is a 13.4% (NREL verified), 1.0 cm{sup 2} solar cell fabricated from material deposited and grown on a graphite cloth substrate. The significant technological hurdle of the program was and remains the low quality of the photovoltaic layer which is caused by contamination of the photovoltaic layer from the low-cost ceramic substrate by trace impurities found in the substrate precursor materials. The ceramic substrate and metallurgical barrier are being developed specifically to solve this problem.

  12. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

    OpenAIRE

    Andreas Krause; Susanne Dörfler; Markus Piwko; Florian M. Wisser; Tony Jaumann; Eike Ahrens; Lars Giebeler; Holger Althues; Stefan Schädlich; Julia Grothe; Andrea Jeffery; Matthias Grube; Jan Brückner; Jan Martin; Jürgen Eckert

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm2. The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D su...

  13. Pamela tracking system status report

    CERN Document Server

    Taccetti, F; Bonechi, L; Bongi, M; Boscherini, M; Castellini, G; D'Alessandro, R; Gabbanini, A; Grandi, M; Papini, P; Piccardi, S; Ricciarini, S; Spillantini, P; Straulino, S; Tesi, M; Vannuccini, E

    2002-01-01

    The Pamela apparatus will be launched at the end of 2002 on board of the Resurs DK Russian satellite. The tracking system, composed of six planes of silicon sensors inserted inside a permanent magnetic field was intensively tested during these last years. Results of tests have shown a good signal-to-noise ratio and an excellent spatial resolution, which should allow to measure the antiproton flux in an energy range from 80 MeV up to 190 GeV. The production of the final detector modules is about to start and mechanical and thermal tests on the tracking tower are being performed according to the specifications of the Russian launcher and satellite.

  14. CERBEROS: A tracking system for secondary pion beams at the HADES spectrometer

    Science.gov (United States)

    Wirth, J.; Fabbietti, L.; Lalik, R.; Maier, L.; Scordo, A.

    2016-07-01

    In 2014 the HADES collaboration performed two successful physics production runs with secondary pion beams. Since secondary pion beams are strongly defocussed in position and momentum, two fast tracking stations were installed along the pion beam chicane following the pion production target providing the momentum measurement of each individual pion. The momentum is reconstructed using the position information of every hit detected by the tracking stations and the beam optics transport calculation with a resolution below 0.5% playing an important role in terms of the exclusive analysis of investigated reactions. Both tracking stations consist of a double-sided silicon strip sensor with a large active area (10 × 10cm2). To guarantee fast tracking, the sensors are read out with the n-XYTER ASIC chip. Due to its self-triggering architecture and local storage capability, the chip enables on-line tracking at high rates (dN / dt >106 part / s). The TRB3 read out board on which the trigger logic is implemented integrates the system into the HADES DAQ. In this report we are showing the results obtained during the calibration experiment with a monochromatic proton beam set at seven different momenta centred around 2.68 GeV/c. Also the excellent performance achieved during the production campaign with a pion beam are presented.

  15. EMC Diagnosis and Corrective Actions for Silicon Strip Tracker Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Arteche, F.; /CERN /Imperial Coll., London; Rivetta, C.; /SLAC

    2006-06-06

    The tracker sub-system is one of the five sub-detectors of the Compact Muon Solenoid (CMS) experiment under construction at CERN for the Large Hadron Collider (LHC) accelerator. The tracker subdetector is designed to reconstruct tracks of charged sub-atomic particles generated after collisions. The tracker system processes analogue signals from 10 million channels distributed across 14000 silicon micro-strip detectors. It is designed to process signals of a few nA and digitize them at 40 MHz. The overall sub-detector is embedded in a high particle radiation environment and a magnetic field of 4 Tesla. The evaluation of the electromagnetic immunity of the system is very important to optimize the performance of the tracker sub-detector and the whole CMS experiment. This paper presents the EMC diagnosis of the CMS silicon tracker sub-detector. Immunity tests were performed using the final prototype of the Silicon Tracker End-Caps (TEC) system to estimate the sensitivity of the system to conducted noise, evaluate the weakest areas of the system and take corrective actions before the integration of the overall detector. This paper shows the results of one of those tests, that is the measurement and analysis of the immunity to CM external conducted noise perturbations.

  16. Qualification of a new supplier for silicon particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dragicevic, M., E-mail: marko.dragicevic@cern.ch [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Bartl, U. [Infineon Technologies Austria AG, Villach (Austria); Bergauer, T.; Frühwirth, E. [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Gamerith, S.; Hacker, J.; Kröner, F.; Kucher, E.; Moser, J.; Neidhart, T. [Infineon Technologies Austria AG, Villach (Austria); Schulze, H.-J. [Infineon Technologies AG, Munich (Germany); Schustereder, W. [Infineon Technologies Austria AG, Villach (Austria); Treberspurg, W. [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Wübben, T. [Infineon Technologies Austria AG, Villach (Austria)

    2013-12-21

    Most modern particle physics experiments use silicon based sensors for their tracking systems. These sensors are able to detect particles generated in high energy collisions with high spatial resolution and therefore allow the precise reconstruction of particle tracks. So far only a few vendors are capable of producing silicon strip sensors with the quality needed in particle physics experiments. Together with the European semiconductor manufacturer Infineon Technologies Austria AG the Institute of High Energy Physics of the Austrian Academy of Sciences developed planar silicon strip sensors in p-on-n technology. This paper presents the development, production and results from the electrical characterisation of the first sensors produced by Infineon.

  17. The STAR Silicon Strip Detector (SSD)

    CERN Document Server

    Arnold, L; Bonnet, D; Boucham, A; Bouvier, S; Castillo, J; Coffin, J P; Drancourt, C; Erazmus, B; Gaudichet, L; Germain, M; Gojak, C; Grabski, J; Guilloux, G; Guedon, M; Hippolyte, B; Janik, M; Kisiel, A; Kuhn, C; Lakehal-Ayat, L; Lefèvre, F; Le Moal, C; Leszczynski, P; Lutz, Jean Robert; Maliszewski, A; Martin, L; Milletto, T; Pawlak, T; Peryt, W; Pluta, J; Przewlocki, M; Radomski, S; Ravel, O; Renard, C; Renault, G; Rigalleau, L M; Roy, C; Roy, D; Suire, C; Szarwas, P; Tarchini, A

    2003-01-01

    The STAR Silicon Strip Detector (SSD) completes the three layers of the Silicon Vertex Tracker (SVT) to make an inner tracking system located inside the Time Projection Chamber (TPC). This additional fourth layer provides two dimensional hit position and energy loss measurements for charged particles, improving the extrapolation of TPC tracks through SVT hits. To match the high multiplicity of central Au+Au collisions at RHIC the double sided silicon strip technology was chosen which makes the SSD a half million channels detector. Dedicated electronics have been designed for both readout and control. Also a novel technique of bonding, the Tape Automated Bonding (TAB), was used to fullfill the large number of bounds to be done. All aspects of the SSD are shortly described here and test performances of produced detection modules as well as simulated results on hit reconstruction are given.

  18. Advanced alignment of the ATLAS tracking system

    CERN Document Server

    Butti, Pierfrancesco; The ATLAS collaboration

    2014-01-01

    In order to reconstruct the trajectories of charged particles, the ATLAS experiment exploits a tracking system built using different technologies, silicon planar modules or microstrips (PIX and SCT detectors) and gaseous drift tubes (TRT), all embedded in a 2T solenoidal magnetic field. Misalignments of the active detector elements and deformations of the structures (which can lead to \\textit{Weak Modes}) deteriorate resolution of the track reconstruction and lead to systematic biases on the measured track parameters. The applied alignment procedures exploit various advanced techniques in order to minimise track-hit residuals and remove detector deformations. For the LHC Run II, the Pixel Detector has been refurbished and upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL).

  19. Simulations of silicon vertex tracker for star experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W. [Lawrence Berkeley Lab., CA (United States); Liko, D. [Institut fur Hochenenergiephysik, Vienna, (Austria); Cramer, J.; Prindle, D.; Trainor, T. [Univ. of Washington, Seattle (United States); Braithwaite, W. [Univ. of Arkansas, Little Rock (United States)

    1991-12-31

    The first computer simulations to optimize the Silicon Vertex Tracker (SVT) designed for the STAR experiment at RHIC are presented. The physics goals and the expected complexity of the events at RHIC dictate the design of a tracking system for the STAR experiment. The proposed tracking system will consist of a silicon vertex tracker (SVT) to locate the primary interaction and secondary decay vertices and to improve the momentum resolution, and a time projection chamber (TPC), positioned inside a solenoidal magnet, for continuous tracking.

  20. INNER TRACKING

    CERN Multimedia

    Peter Sharp

    The Silicon Strip Tracker was successfully installed into CMS on December 15, and was subsequently aligned to the LHC beam line to +/- 1mm. Before the Tracker was installed all of the connections from the low voltage power supplies, the cooling plants and optical readout fibres from the ‘off detector’ electronics had been installed to Patch Panel 1 (PP1), on the CMS magnet cryostat, and thoroughly tested. The careful connection of the Tracker to PP1 started in early January and will be completed in early March, just before the central section of the LHC beam pipe is installed into CMS. After initial checks of all the safety interlocks and the cooling circuits, the quality of each of the connections will be verified by commissioning each section of the Tracker in turn and reading back the calibration pulses (tick marks) from the front-end electronics. This process verifies that all of the connections are correct and in particular, that the quality of the fibre connections is good. When ...

  1. Silicon nanotube field effect transistor with core-shell gate stacks for enhanced high-performance operation and area scaling benefits

    KAUST Repository

    Fahad, Hossain M.

    2011-10-12

    We introduce the concept of a silicon nanotube field effect transistor whose unique core-shell gate stacks help achieve full volume inversion by giving a surge in minority carrier concentration in the near vicinity of the ultrathin channel and at the same time rapid roll-off at the source and drain junctions constituting velocity saturation-induced higher drive current-enhanced high performance per device with efficient real estate consumption. The core-shell gate stacks also provide superior short channel effects control than classical planar metal oxide semiconductor field effect transistor (MOSFET) and gate-all-around nanowire FET. The proposed device offers the true potential to be an ideal blend for quantum ballistic transport study of device property control by bottom-up approach and high-density integration compatibility using top-down state-of-the-art complementary metal oxide semiconductor flow. © 2011 American Chemical Society.

  2. The alignment of the CMS Silicon Tracker

    International Nuclear Information System (INIS)

    The complex system of the CMS all-silicon Tracker, with 15 148 silicon strip and 1440 silicon pixel modules, requires sophisticated alignment procedures. In order to achieve an optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of few micrometers. We present results of the alignment of the full Tracker, in its final position, used for the reconstruction of the first collisions recorded by the CMS experiment. The aligned geometry is based on the analysis of several million reconstructed tracks recorded during the commissioning of the CMS experiment, both with cosmic rays and with the first proton-proton collisions. The geometry has been systematically monitored in the different periods of operation of the CMS detector. The results have been validated by several data-driven studies (laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution) and compared with predictions obtained from a detailed detector simulation. (author)

  3. The Alignment of the CMS Silicon Tracker

    International Nuclear Information System (INIS)

    The complex system of the CMS all-silicon Tracker, with 15148 silicon strips and 1440 silicon pixel modules, requires sophisticated alignment procedures. In order to achieve an optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of few micrometers. We present results of the alignment of the full Tracker, in its final position, used for the reconstruction of the first collisions recorded by the CMS experiment. The aligned geometry is based on the analysis of several million reconstructed tracks recorded during the commissioning of the CMS experiment, both with cosmic rays and with the first proton-proton collisions. The geometry has been systematically monitored in the different periods of operation of the CMS detector. The results have been validated by several data-driven studies (laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution) and compared with predictions obtained from a detailed detector simulation.

  4. Track Construction Manual.

    Science.gov (United States)

    Banke, Ron; Di Gennaro, Guy; Ediger, Rick; Garner, Lanny; Hersom, Steve; Miller, Jack; Nemeth, Ron; Petrucelli, Jim; Sierks, Donna; Smith, Don; Swank, Kevin; West, Kevin

    This book establishes guidelines for the construction and maintenance of tracks by providing information for building new tracks or upgrading existing tracks. Subjects covered include running track planning and construction, physical layout, available surfaces, and maintenance. General track requirements and construction specifications are…

  5. A Printable Silicon Nano-Field Effect Transistor with High Operating Frequency for Large-Area Deployable Active Phased-Array Antennas Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flexible electronic circuits can be easily integrated with large area (>10m aperture), inflatable antennas to provide distributed control and processing...

  6. Dose reduction in skeletal and chest radiography using a large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide: technical background, basic image quality parameters, and review of the literature

    International Nuclear Information System (INIS)

    The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality. (orig.)

  7. Dose reduction in skeletal and chest radiography using a large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide: technical background, basic image quality parameters, and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Voelk, Markus; Hamer, Okka W.; Feuerbach, Stefan [Department of Diagnostic Radiology, University Hospital of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg (Germany); Strotzer, Michael [Department of Radiology, Hospital Hohe Warte, Hohe Warte 8, 95445, Bayreuth (Germany)

    2004-05-01

    The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality. (orig.)

  8. Variable-density groundwater flow simulations and particle tracking. Numerical modelling using DarcyTools. Preliminary site description of the Simpevarp area, version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven [SF GeoLogic AB, Stockholm (Sweden); Stigsson, Martin; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Svensson, Urban [Computer-aided Fluid Engineering AB, Norrkoeping (Sweden)

    2004-12-01

    SKB is conducting site investigations for a high-level nuclear waste repository in fractured crystalline rocks at two coastal areas in Sweden, Forsmark and Simpevarp. The investigations started in 2002 and have been planned since the late 1990s. The work presented here investigates the possibility of using hydrogeochemical measurements in deep boreholes to reduce parameter uncertainty in a regional modelling of groundwater flow in fractured rock. The work was conducted with the aim of improving the palaeohydrogeological understanding of the Simpevarp area and to give recommendations to the preparations of the next version of the Preliminary Site Description (1.2). The study is based on a large number of numerical simulations of transient variable density groundwater flow through a strongly heterogeneous and anisotropic medium. The simulations were conducted with the computer code DarcyTools, the development of which has been funded by SKB. DarcyTools is a flexible porous media code specifically designed to treat groundwater flow and salt transport in sparsely fractured crystalline rock and it is noted that some of the features presented in this report are still under development or subjected to testing and verification. The simulations reveal the sensitivity of the results to different hydrogeological modelling assumptions, e.g. the sensitivity to the initial groundwater conditions at 10,000 BC, the size of the model domain and boundary conditions, and the hydraulic properties of deterministically and stochastically modelled deformation zones. The outcome of these simulations was compared with measured salinities and calculated relative proportions of different water types (mixing proportions) from measurements in two deep core drilled boreholes in the Laxemar subarea. In addition to the flow simulations, the statistics of flow related transport parameters were calculated for particle flowpaths from repository depth to ground surface for two subareas within the

  9. Variable-density groundwater flow simulations and particle tracking. Numerical modelling using DarcyTools. Preliminary site description of the Simpevarp area, version 1.1

    International Nuclear Information System (INIS)

    SKB is conducting site investigations for a high-level nuclear waste repository in fractured crystalline rocks at two coastal areas in Sweden, Forsmark and Simpevarp. The investigations started in 2002 and have been planned since the late 1990s. The work presented here investigates the possibility of using hydrogeochemical measurements in deep boreholes to reduce parameter uncertainty in a regional modelling of groundwater flow in fractured rock. The work was conducted with the aim of improving the palaeohydrogeological understanding of the Simpevarp area and to give recommendations to the preparations of the next version of the Preliminary Site Description (1.2). The study is based on a large number of numerical simulations of transient variable density groundwater flow through a strongly heterogeneous and anisotropic medium. The simulations were conducted with the computer code DarcyTools, the development of which has been funded by SKB. DarcyTools is a flexible porous media code specifically designed to treat groundwater flow and salt transport in sparsely fractured crystalline rock and it is noted that some of the features presented in this report are still under development or subjected to testing and verification. The simulations reveal the sensitivity of the results to different hydrogeological modelling assumptions, e.g. the sensitivity to the initial groundwater conditions at 10,000 BC, the size of the model domain and boundary conditions, and the hydraulic properties of deterministically and stochastically modelled deformation zones. The outcome of these simulations was compared with measured salinities and calculated relative proportions of different water types (mixing proportions) from measurements in two deep core drilled boreholes in the Laxemar subarea. In addition to the flow simulations, the statistics of flow related transport parameters were calculated for particle flowpaths from repository depth to ground surface for two subareas within the

  10. The ALICE silicon strip detector system

    CERN Document Server

    Kuijer, P

    2000-01-01

    ALICE (A Large Ion Collider Experiment) is an experiment at the Large Hadron Collider (LHC) optimized for the study of heavy-ion collisions at a centre-of-mass energy of 5.5 TeV per nucleon. The detector consists essentially of two main components: the central part, composed of detectors mainly devoted to the study of hadronic signals and dielectrons, and the forward muon spectrometer devoted to the study of quarkonia behaviour in dense matter. The central part, which covers +-45 deg. (|eta|<0.9) over the full azimuth, is embedded in a large magnet with a weak solenoidal field. Outside of the Inner Tracking System (ITS), there are a cylindrical TPC and a large area PID array of time-of-flight (TOF) counters. In addition, there are two small-area single-arm detectors: an electromagnetic calorimeter (Photon Spectrometer, PHOS) and an array of RICH counters optimized for high-momentum inclusive particle identification (HMPID). This article describes the silicon strip detector system used in the outer layers o...

  11. Eye-Tracking Investigations Exploring How Students Learn Geology from Photographs and The Structural Setting of Hydrothermal Gold Deposits in the San Antonio Area, B.C.S., MX

    Science.gov (United States)

    Coyan, Joshua

    Geoscience educators commonly teach geology by projecting a photograph in front of the class. Geologic photographs often contain animals, people, and inanimate objects that help convey the scale of features in the photograph. Although scale items seem innocuous to instructors and other experts, the presence of such items is distracting and has a profound effect on student learning behavior. To evaluate how students visually interact with distracting scale items in photographs and to determine if cueing or signaling is an effective means to direct students to pertinent information, students were eye tracked while looking at geologically-rich photographs. Eye-tracking data revealed that learners primarily looked at the center of an image, focused on faces of both humans and animals if they were present, and repeatedly returned to looking at the scale item (distractor) for the duration an image was displayed. The presence of a distractor caused learners to look at less of an image than when a distractor was not present. Learners who received signaling tended to look at the distractor less, look at the geology more, and surveyed more of the photograph than learners who did not receive signaling. The San Antonio area in the southern part of the Baja California Peninsula is host to hydrothermal gold deposits. A field study, including drill-core analysis and detailed geologic mapping, was conducted to determine the types of mineralization present, the types of structures present, and the relationship between the two. This investigation revealed that two phases of mineralization have occurred in the area; the first is hydrothermal deposition of gold associated with sulfide deposits and the second is oxidation of sulfides to hematite, goethite, and jarosite. Mineralization varies as a function of depth, whereas sulfides occurring at depth, while minerals indicative of oxidation are limited to shallow depths. A structural analysis revealed that the oldest structures in the

  12. Silicon photonics for telecommunications and biomedicine

    CERN Document Server

    Fathpour, Sasan

    2011-01-01

    Given silicon's versatile material properties, use of low-cost silicon photonics continues to move beyond light-speed data transmission through fiber-optic cables and computer chips. Its application has also evolved from the device to the integrated-system level. A timely overview of this impressive growth, Silicon Photonics for Telecommunications and Biomedicine summarizes state-of-the-art developments in a wide range of areas, including optical communications, wireless technologies, and biomedical applications of silicon photonics. With contributions from world experts, this reference guides

  13. Growth Mechanism of Silicon Carbide (SIC) on Clean Silicon Surfaces

    International Nuclear Information System (INIS)

    products. For low acetylene exposure, almost the entire surface appears sqrt(3)xsqrt(3)-R30 degrees reconstructed but islands, mainly decorating the step edges, are generally surrounded by 7x7 reconstructed areas, located deeper with respect to the plane of sqrt(3)xsqrt(3)-R degrees reconstruction. For highest acetylene dose, the surface is characterized by nanostructures and large holes (as deep as 3-5 nm) that occupy one of more terraces between the original silicon surface step edges with their inner side constituted of islands itself. For intermediate acetylene exposure, the small increase (from 50 degrees to 700 degrees) of substrate temperature during the reaction is sufficient to make the resulting carbonization mechanism switch towards the highest exposure behaviour. The process can be described as the competitive effect of three mechanisms all providing silicon atoms for the reaction: the first involves the first stages of carbonization when carbon atoms are incorporated in substitutional sites in the silicon matrix and silicon atoms are released free to move on the surface and to participate to nanostructure formation; the second, occurring after the first nucleus of the nanostructure has grown, attracts silicon atoms from neighbouring areas towards the nanostructure itself and produces around it depleted zones characterized by silicon 7x7 reconstruction; the third, prevailing at highest acetylene doses, supplies silicon atoms from the bulk towards the surface to react with carbon atoms leaving voids in the matrix beneath. Experimental conditions, i.e. substrate temperature during reaction and acetylene dose, are found to condition the growth process by favouring one or more mechanisms

  14. Sampling strong tracking nonlinear unscented Kalman filter and its application in eye tracking

    International Nuclear Information System (INIS)

    The unscented Kalman filter is a developed well-known method for nonlinear motion estimation and tracking. However, the standard unscented Kalman filter has the inherent drawbacks, such as numerical instability and much more time spent on calculation in practical applications. In this paper, we present a novel sampling strong tracking nonlinear unscented Kalman filter, aiming to overcome the difficulty in nonlinear eye tracking. In the above proposed filter, the simplified unscented transform sampling strategy with n + 2 sigma points leads to the computational efficiency, and suboptimal fading factor of strong tracking filtering is introduced to improve robustness and accuracy of eye tracking. Compared with the related unscented Kalman filter for eye tracking, the proposed filter has potential advantages in robustness, convergence speed, and tracking accuracy. The final experimental results show the validity of our method for eye tracking under realistic conditions. (classical areas of phenomenology)

  15. Evaluating Crop Area Mapping from MODIS Time-Series as an Assessment Tool for Zimbabwe’s “Fast Track Land Reform Programme”

    Science.gov (United States)

    2016-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) data forms the basis for numerous land use and land cover (LULC) mapping and analysis frameworks at regional scale. Compared to other satellite sensors, the spatial, temporal and spectral specifications of MODIS are considered as highly suitable for LULC classifications which support many different aspects of social, environmental and developmental research. The LULC mapping of this study was carried out in the context of the development of an evaluation approach for Zimbabwe’s land reform program. Within the discourse about the success of this program, a lack of spatially explicit methods to produce objective data, such as on the extent of agricultural area, is apparent. We therefore assessed the suitability of moderate spatial and high temporal resolution imagery and phenological parameters to retrieve regional figures about the extent of cropland area in former freehold tenure in a series of 13 years from 2001–2013. Time-series data was processed with TIMESAT and was stratified according to agro-ecological potential zoning of Zimbabwe. Random Forest (RF) classifications were used to produce annual binary crop/non crop maps which were evaluated with high spatial resolution data from other satellite sensors. We assessed the cropland products in former freehold tenure in terms of classification accuracy, inter-annual comparability and heterogeneity. Although general LULC patterns were depicted in classification results and an overall accuracy of over 80% was achieved, user accuracies for rainfed agriculture were limited to below 65%. We conclude that phenological analysis has to be treated with caution when rainfed agriculture and grassland in semi-humid tropical regions have to be separated based on MODIS spectral data and phenological parameters. Because classification results significantly underestimate redistributed commercial farmland in Zimbabwe, we argue that the method cannot be used to produce

  16. NEW TRACK-TO-TRACK CORRELATION ALGORITHMS BASED ON BITHRESHOLD IN A DISTRIBUTED MULTISENSOR INFORMATION FUSION SYSTEM

    OpenAIRE

    Liu Yu; Wang Haipeng; He You; Dong Kai; Xiao Chuwan

    2013-01-01

    Track-to-Track correlation (or association) is an ongoing area of interest in the field of distributed multisensory information fusion. In order to perform accurately identifying tracks with common origin and get fast convergence, this study presents independent and dependent Bi-threshold Track Correlation Algorithms (called BTCAs), which are described in detail and the track correlation mass and multivalency processing methods are discussed as well. Then, Based on BTCAs, two modified Bi-thre...

  17. Characterization of PM2.5/PM2.5-10 and source tracking in the juncture belt between urban and rural areas of Beijing

    Institute of Scientific and Technical Information of China (English)

    WANG HaiLin; ZHOU YuMin; ZHUANG YaHui; WANG XiaoKe; HAO ZhengPing

    2009-01-01

    Coarse (PM2.5-10) and fine (PM2.5) atmospheric particulate samples were collected in summer and winter during 2005-2007 in the juncture belt between urban and rural areas of Beijing. Elements, ions, organic/elemental carbon (OC/EC) and polynuclear aromatic hydrocarbons (PAHs) were determined to obtain some latest information about the particulate pollution in the juncture belt of Beijing. Particulate matter levels at this site were high as compared with the levels at other sampling sites in Beijing. Pollution elements, secondary ions and PAHs were enriched in fine particles rather than in coarse particles. An obvious seasonal variation of the chemical composition of PM was observed. Source apportionment results showed that secondary components were the largest mass contributor of PM2.5, accounting for 28%; whereas soil-related sources were the largest contributor of PM2.5-10, explaining about 49% of the total mass. The abnormal levels of soil heavy metals at the electronic waste disassembly site in the upwind villages suggested the potential impact of such activities to the environment.

  18. LHCb : Tracking system of the LHCb upgrade

    CERN Multimedia

    Szumlak, Tomasz

    2015-01-01

    The upgrade of the LHCb experiment will run at an instantaneous luminosity of 2x10^33 cm^-2 s^-1 with a fully software based trigger, allowing to read out the detector at a rate of 40MHz. For this purpose, the full tracking system will be newly developed: the vertex locator (VELO) will be replaced by a pixel-based detector, withstanding the high radiation dose and providing an excellent track reconstruction with an efficiency of above 99% for all charged particles of interest. Upstream of the magnet, a silicon mico-strip detector with a high granularity and an improved acceptance coverage, called the Upstream Tracker (UT), will replace the current silicon strip tracker, and provide a rough momentum estimate. The tracking system downstream of the magnet will be replaced by the Scintillating Fibre tracker (SciFi), which will consist of 12 layers using 2.5m long scintillating fibres read out by silicon photo-multipliers, providing a spatial resolution better than 100 micron and resulting in a total momentum reso...

  19. A hybrid silicon pixel telescope tested in a heavy-ion experiment

    International Nuclear Information System (INIS)

    Specific features of the OMEGA-ION pixel detector are the adjustable delay with external trigger capability and the detector leakage current compensation. A row of pixels can be used for testing the electrical performance of the amplifier and comparator circuits. Detailed results of these electrical tests are presented. A telescope made of three OMEGA-ION hybrid silicon pixel detectors has been successfully tested in the heavy-ion experiment WA94. Each plane consisted of a single detector with 1006 active pixels (500 μm x 75 μm), each one being bump-bonded to the readout chip, and arranged in 16 columns and 63 rows respectively. With a sensitive area as small as 8000x4725 μm2 several million events with at least one track originating from the sulphur-sulphur interaction have been recorded in a few hours. Results on target reconstruction, tracking accuracy and efficiency are presented. (orig.)

  20. The availabilities of arsenic and cadmium in rice paddy fields from a mining area: The role of soil extractable and plant silicon.

    Science.gov (United States)

    Yu, Huan-Yun; Ding, Xiaodong; Li, Fangbai; Wang, Xiangqin; Zhang, Shirong; Yi, Jicai; Liu, Chuanping; Xu, Xianghua; Wang, Qi

    2016-08-01

    Adequate silicon (Si) can greatly boost rice yield and improve grain quality through alleviating stresses associated with heavy metals and metalloids such as arsenic (As) and cadmium (Cd). The soil plant-available Si is relatively low in South China due to severe desilicification and allitization of the soils in this region. Conversely, pollution of heavy metals and metalloids in the soils of this region occurs widely, especially As and Cd pollution in paddy soil. Therefore, evaluating the plant availability of Si in paddy soil of South China and examining its correlation with the availability of heavy metals and metalloids are of great significance. Accordingly, in our study, 107 pairs of soil and rice plant samples were collected from paddy fields contaminated by As and Cd in South China. Significantly positive correlations between Si in rice plants and Si fractions in soils extracted with citric acid, NaOAc-HOAc buffer, and oxalate-ammonium oxalate buffer suggest that these extractants are more suitable for use in extracting plant-available Si in the soils of our present study. Significantly negative correlations between different Si fractions and As or Cd in rice plant tissues and negative exponential correlations between the molar ratios of Si to As/Cd in rice roots, straws, husks or grains and As/Cd in rice grains indicate that Si can significantly alleviate the accumulation of As/Cd from soils to the rice plants. Finally, a contribution assessment of soil properties to As/Cd accumulation in rice grains based on random forest showed that in addition to Si concentrations in soil or rice plants, other factors such as Fe fractions and total phosphorus also contributed largely to As/Cd accumulation in rice grains. Overall, Si exhibited its unique role in mitigating As or Cd stress in rice, and our study results provide strong field evidence for this role. PMID:27209244

  1. Sintered silicon carbide

    International Nuclear Information System (INIS)

    A sintered silicon carbide body having a predominantly equiaxed microstructure consists of 91 to 99.85% by weight of silicon carbide at least 95% of which is the alpha phase, up to 5.0% by weight carbonized organic material, 0.15 to 3.0% of boron, and up to 1.0% by weight additional carbon. A mixture of 91 to 99.85 parts by weight silicon carbide having a surface area of 1 to 100 m2/g, 0.67 to 20 parts of a carbonizable organic binder with a carbon content of at least 33% by weight, 0.15 to 5 parts of a boron source containing 0.15 to 3.0 parts by weight boron and up to 15 parts by weight of a temporary binder is mixed with a solvent, the mixture is then dried, shaped to give a body with a density of at least 1.60 g/cc and fired at 1900 to 22500C to obtain an equiaxed microstructure. (author)

  2. Nanocrystalline silicon based thin film solar cells

    Science.gov (United States)

    Ray, Swati

    2012-06-01

    Amorphous silicon solar cells and panels on glass and flexible substrate are commercially available. Since last few years nanocrystalline silicon thin film has attracted remarkable attention due to its stability under light and ability to absorb longer wavelength portion of solar spectrum. For amorphous silicon/ nanocrystalline silicon double junction solar cell 14.7% efficiency has been achieved in small area and 13.5% for large area modules internationally. The device quality nanocrystalline silicon films have been fabricated by RF and VHF PECVD methods at IACS. Detailed characterizations of the materials have been done. Nanocrystalline films with low defect density and high stability have been developed and used as absorber layer of solar cells.

  3. Solar tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Nielson, Gregory N.

    2016-07-12

    Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

  4. Online track reconstruction at hadron colliders

    International Nuclear Information System (INIS)

    Real time event reconstruction plays a fundamental role in High Energy Physics experiments. Reducing the rate of data to be saved on tape from millions to hundreds per second is critical. In order to increase the purity of the collected samples, rate reduction has to be coupled with the capability to simultaneously perform a first selection of the most interesting events. A fast and efficient online track reconstruction is important to effectively trigger on leptons and/or displaced tracks from b-quark decays. This talk will be an overview of online tracking techniques in different HEP environments: we will show how H1 experiment at HERA faced the challenges of online track reconstruction implementing pattern matching and track linking algorithms on CAMs and FPGAs in the Fast Track Processor (FTT). The pattern recognition technique is also at the basis of the Silicon Vertex Trigger (SVT) at the CDF experiment at Tevatron: coupled to a very fast fitting phase, SVT allows to trigger on displaced tracks, thus greatly increasing the efficiency for the hadronic B decay modes. A recent upgrade of the SVT track fitter, the Giga-fitter, can perform more than 1 fit/ns and further improves the CDF online trigger capabilities at high luminosity. At SLHC, where luminosities will be 2 orders of magnitude greater than Tevatron, online tracking will be much more challenging: we will describe CMS future plans for a Level-1 track trigger and the Fast Tracker (FTK) processor at the ATLAS experiment, based on the Giga-fitter architecture and designed to provide high quality tracks reconstructed over the entire detector in time for a Level-2 trigger decision.luminosity. At SLHC, where luminosities will be 2 orders of magnitude greater than Tevatron, online tracking will be much more challenging: we will describe CMS future plans for a Level-1 track trigger and the Fast Tracker (FTK) processor at the Atlas experiment, based on the Giga-fitter architecture and designed to provide high

  5. The CMS Silicon Tracker Alignment

    CERN Document Server

    Castello, R

    2008-01-01

    The alignment of the Strip and Pixel Tracker of the Compact Muon Solenoid experiment, with its large number of independent silicon sensors and its excellent spatial resolution, is a complex and challenging task. Besides high precision mounting, survey measurements and the Laser Alignment System, track-based alignment is needed to reach the envisaged precision.\\\\ Three different algorithms for track-based alignment were successfully tested on a sample of cosmic-ray data collected at the Tracker Integration Facility, where 15\\% of the Tracker was tested. These results, together with those coming from the CMS global run, will provide the basis for the full-scale alignment of the Tracker, which will be carried out with the first \\emph{p-p} collisions.

  6. Digital radiography of the skeleton using a large-area detector based on amorphous silicon technology: Image quality and potential for dose reduction in comparison with screen-film radiography

    International Nuclear Information System (INIS)

    AIM: The purpose of this study was to evaluate a large-area, flat-panel X-ray detector (FD), based on caesium-iodide (CsI) and amorphous silicon (a-Si) with respect to skeletal radiography. Conventional images were compared with digital radiographs using identical and reduced radiation doses. MATERIALS AND METHODS: Thirty consecutive patients were studied prospectively using conventional screen-film radiography (SFR; detector dose 2.5 μGy). Digital images were taken from the same patients with detector doses of 2.5, 1.25 and 0.625 μGy, respectively. The active-matrix detector had a panel size of 43 x 43 cm, a matrix of 3 x 3K, and a pixel size of 143 μm. All hard copies were presented in a random order to eight independent observers, who rated image quality according to subjective quality criteria. Results were assessed for significance using the Student's t -test (confidence level 95%). RESULTS: A statistically significant preference for digital over conventional images was revealed for all quality criteria, except for over-exposure (detector dose 2.5 μGy). Digital images with a 50% dose showed a small, statistically not significant, inferiority compared with SFR. The FD-technique was significantly inferior to SFR at 75% dose reduction regarding bone cortex and trabecula, contrast and overall impression. No statistically significant differences were found with regard to over- and under-exposure and soft tissue presentation. CONCLUSION: Amorphous silicon-based digital radiography yields good image quality. The potential for dose reduction depends on the clinical query. Volk, M. (2000)

  7. Silicon Drift Detectors development for position sensing

    International Nuclear Information System (INIS)

    Novel Silicon Drift Detectors (SDDs) with multi-linear architecture specifically intended for 2D position sensing and imaging applications are presented and their achievable spatial, energy and time resolution are discussed. The capability of providing a fast timing of the interaction with nanosecond time resolution is a new available feature that allows operating the drift detector in continuous readout mode for coincidence imaging applications either with an external trigger or in self-timing. The application of SDDs with multi-linear architecture to Compton electrons' tracking within a single silicon layer and the achieved experimental results will be discussed

  8. Characterization of 36 pixel silicon PAD detectors

    International Nuclear Information System (INIS)

    As silicon detectors offer good energy resolution and high reliability, these are ideally suited for tracking and calorimetric applications in nuclear and particle physics experiments. The band gap of silicon is small enough to produce a good number of charge carriers per unit energy loss of the ionizing particles. Further, the high material density (2.33 g/cm3) leads to a large energy loss per traversed length for ionizing particle (3.8 MeV/cm for a minimum ionizing particle). The semiconductor fabrication technology is now mature enough to produce low leakage and fast response detectors, as the mobility degradation is minimum due to doping

  9. The D0 silicon microstrip tracker

    CERN Document Server

    Quinn, B

    2003-01-01

    The D0 collaboration has completed building a 793,000 channel silicon microstrip tracker for the D0 upgrade. The tracker consists of 768 ladder and wedge assemblies including both single- and double-sided detectors. Detector readout utilizes the SVX-IIE radiation hard chip with on-chip digitization and sparsification. A brief review of the detector design is presented along with results from the assembly and testing processes. The operation of the full readout chain and the performance of the silicon tracker are described. Finally, lessons for future production of large scale tracking systems are discussed.

  10. The Silicon Tracker of the LHCb experiment

    CERN Document Server

    Köstner, S; Agari, M; Bauer, C; Baumeister, D; Bay, A; Bernhard, R P; Bernet, R; Blouw, J; Carron, B; Ermoline, Y; Esperante-Pereira, D; Frei, R; Gassner, J; Hofmann, W; Jiménez-Otero, S; Knöpfle, K T; Lehner, F; Löchner, S L; Lois, C; Needham, M; Perron, A; Pugatch, V; Schmelling, M; Schwingenheuer, B; Siegler, M; Steinkamp, O; Straumann, U; Tran, M T; Vazques, P; Vollhardt, A; Volyanskyy, D; Voss, H

    2004-01-01

    LHCb is one of the experiments of the Large Hadron Collider at CERN, dedicated to B-physics and CP-violation measurements. To fully exploit the physics potential, a good tracking performance with high efficiency in a high particle density environment close to the beam pipe is required. Silicon strip detectors with large read-out pitch and long strips will be used for the LHCb Inner Tracker after the magnet and the Trigger Tracker station in front of the magnet. We report here about the design of the Silicon Tracker, test beam results and the electrical tests foreseen during module production.

  11. Two-track categories

    CERN Document Server

    Blanc, David

    2010-01-01

    We describe a 2-dimensional analogue of track categories, called two-track categories, and show that it can be used to model categories enriched in 2-type mapping spaces. We also define a Baues-Wirsching type cohomology theory for track categories, and explain how it can be used to classify two-track extensions of a track category D by a module over D.

  12. FPGA helix tracking algorithm for PANDA

    International Nuclear Information System (INIS)

    The PANDA detector is a general-purpose detector for physics with high luminosity cooled antiproton beams, planed to operate at the FAIR facility in Darmstadt, Germany. The central detector includes a silicon Micro Vertex Detector (MVD) and a Straw Tube Tracker (STT). Without any hardware trigger, large amounts of raw data are streaming into the data acquisition system. The data reduction task is performed in the online system by reconstruction algorithms programmed in VHDL (Very High Speed Integrated Circuit Hardware Description Language) on FPGAs (Field Programmable Gate Arrays) as first level and on a farm of GPUs or PCs as a second level. One important part in the system is the online track reconstruction. In this presentation, an online tracking finding algorithm for helix track reconstruction in the solenoidal field is shown. A performance study using C++ and the status of the VHDL implementation are presented.

  13. FPGA helix tracking algorithm for PANDA

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yutie; Galuska, Martin; Gessler, Thomas; Hu, Jifeng; Kuehn, Wolfgang; Lange, Jens Soeren; Muenchow, David; Spruck, Bjoern [II. Physikalisches, Giessen University (Germany); Ye, Hua [II. Physikalisches, Giessen University (Germany); Institute of High Energy Physics, Beijing (China); Collaboration: PANDA-Collaboration

    2014-07-01

    The PANDA detector is a general-purpose detector for physics with high luminosity cooled antiproton beams, planed to operate at the FAIR facility in Darmstadt, Germany. The central detector includes a silicon Micro Vertex Detector (MVD) and a Straw Tube Tracker (STT). Without any hardware trigger, large amounts of raw data are streaming into the data acquisition system. The data reduction task is performed in the online system by reconstruction algorithms programmed in VHDL (Very High Speed Integrated Circuit Hardware Description Language) on FPGAs (Field Programmable Gate Arrays) as first level and on a farm of GPUs or PCs as a second level. One important part in the system is the online track reconstruction. In this presentation, an online tracking finding algorithm for helix track reconstruction in the solenoidal field is shown. A performance study using C++ and the status of the VHDL implementation are presented.

  14. Partial crystallization of silicon by high intensity laser irradiation

    International Nuclear Information System (INIS)

    Commercial single crystal silicon wafers and amorphous silicon films piled on single crystal silicon wafers were irradiated with a femtosecond pulsed laser and a nanosecond pulsed laser at irradiation intensities between 1017 W/cm2 and 109 W/cm2. In the single crystal silicon substrate, the irradiated area was changed to polycrystalline silicon and the piled silicon around the irradiated area has spindly column structures constructed of polycrystalline and amorphous silicon. In particular, in the case of the higher irradiation intensity of 1016 W/cm2, the irradiated area was oriented to the same crystal direction as the substrate. In the case of the lower irradiation intensity of 108 W/cm2, only amorphous silicon was observed around the irradiated area, even when the target was single crystal silicon. In contrast, only amorphous silicon particles were found to be piled on the amorphous silicon film, irrespective of the intensity and pulse duration. Three-dimensional thermal diffusion equation for the piled particles on the substrate was solved by using the finite difference methods. The results of our heat-flow simulation of the piled particles almost agree with the experimental results.

  15. Silicone chain extender

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a silicone chain extender, more particularly a chain extender for silicone polymers and copolymers, to a chain extended silicone polymer or copolymer and to a functionalized chain extended silicone polymer or copolymer, to a method for the preparation thereof and...

  16. International Ice Patrol Iceberg Drift Tracks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The International Ice Patrol (IIP) tracks, plots and predicts iceberg positions in the North Atlantic Ocean. The IIP area of responsibility is 40 to 52 degrees...

  17. The ALICE Silicon Pixel Detector System

    CERN Document Server

    Fadmar Osmic, FO

    2006-01-01

    The European Organization for Particle Physics (CERN) in Geneva is currently constructing the Large Hadron Collider (LHC), which will allow the study of the subnuclear ranges of physics with an accuracy never achieved before. Within the LHC project, ALICE is to the study of strongly interacting matter at extreme densities and high temperatures. ALICE as many other modern High Energy Physics (HEP) experiments uses silicon pixel detectors for tracking close to the interaction point (IP). The ALICE Silicon Pixel Detector (SPD) will constitute the two innermost layers of ALICE, and will due to its high granularity provide precise tracking information. In heavy ion collisions, the track density could be as high as 80 tracks/cm2 in the first SPD layer. The SPD will provide tracking information at radii of 3.9 and 7.6 cm from the IP. It is a fundamental element for the study of the weak decays of the particles carrying heavy flavour, whose typical signature will be a secondary vertex separated from the primary verte...

  18. Method of fabricating porous silicon carbide (SiC)

    Science.gov (United States)

    Shor, Joseph S. (Inventor); Kurtz, Anthony D. (Inventor)

    1995-01-01

    Porous silicon carbide is fabricated according to techniques which result in a significant portion of nanocrystallites within the material in a sub 10 nanometer regime. There is described techniques for passivating porous silicon carbide which result in the fabrication of optoelectronic devices which exhibit brighter blue luminescence and exhibit improved qualities. Based on certain of the techniques described porous silicon carbide is used as a sacrificial layer for the patterning of silicon carbide. Porous silicon carbide is then removed from the bulk substrate by oxidation and other methods. The techniques described employ a two-step process which is used to pattern bulk silicon carbide where selected areas of the wafer are then made porous and then the porous layer is subsequently removed. The process to form porous silicon carbide exhibits dopant selectivity and a two-step etching procedure is implemented for silicon carbide multilayers.

  19. Silicon Micromachining

    Science.gov (United States)

    Elwenspoek, Miko; Jansen, Henri V.

    2004-08-01

    This comprehensive book provides an overview of the key techniques used in the fabrication of micron-scale structures in silicon. Recent advances in these techniques have made it possible to create a new generation of microsystem devices, such as microsensors, accelerometers, micropumps, and miniature robots. The authors underpin the discussion of each technique with a brief review of the fundamental physical and chemical principles involved. They pay particular attention to methods such as isotropic and anisotropic wet chemical etching, wafer bonding, reactive ion etching, and surface micromachining. There is a special section on bulk micromachining, and the authors also discuss release mechanisms for movable microstructures. The book is a blend of detailed experimental and theoretical material, and will be of great interest to graduate students and researchers in electrical engineering and materials science whose work involves the study of micro-electromechanical systems (MEMS).

  20. Tracking facial features with occlusions

    Institute of Scientific and Technical Information of China (English)

    MARKIN Evgeny; PRAKASH Edmond C.

    2006-01-01

    Facial expression recognition consists of determining what kind of emotional content is presented in a human face.The problem presents a complex area for exploration, since it encompasses face acquisition, facial feature tracking, facial expression classification. Facial feature tracking is of the most interest. Active Appearance Model (AAM) enables accurate tracking of facial features in real-time, but lacks occlusions and self-occlusions. In this paper we propose a solution to improve the accuracy of fitting technique. The idea is to include occluded images into AAM training data. We demonstrate the results by running ex periments using gradient descent algorithm for fitting the AAM. Our experiments show that using fitting algorithm with occluded training data improves the fitting quality of the algorithm.

  1. Thin silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B.; Bacon, C.; DiReda, V.; Ford, D.H.; Ingram, A.E.; Cotter, J.; Hughes-Lampros, T.; Rand, J.A.; Ruffins, T.R.; Barnett, A.M. [Astro Power Inc., Solar Park, Newark, DE (United States)

    1992-12-01

    The silicon-film design achieves high performance by using a dun silicon layer and incorporating light trapping. Optimally designed thin crystalline solar cells (<50 microns thick) have performance advantages over conventional thick devices. The high-performance silicon-film design employs a metallurgical barrier between the low-cost substrate and the thin silicon layer. Light trapping properties of silicon-film on ceramic solar cells are presented and analyzed. Recent advances in process development are described here.

  2. The design of the L3 silicon microvertex detector

    International Nuclear Information System (INIS)

    An upgrade of the L3 central tracking system, a silicon microvertex detector (SMD), is described. The detector consists of two layers of silicon, each equipped for rφ and z readout with resolution ≅6 μm and ≅20 μm respectively. The SMD will provide full azimuthal coverage over the polar angular range 22deg≤θ≤158deg. The total thickness is ≅0.9% of one radiation length. (orig.)

  3. 3D, Flash, Induced Current Readout for Silicon Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Sherwood I.

    2014-06-07

    A new method for silicon microstrip and pixel detector readout using (1) 65 nm-technology current amplifers which can, for the first time with silicon microstrop and pixel detectors, have response times far shorter than the charge collection time (2) 3D trench electrodes large enough to subtend a reasonable solid angle at most track locations and so have adequate sensitivity over a substantial volume of pixel, (3) induced signals in addition to, or in place of, collected charge

  4. SILICON REFINING BY VACUUM TREATMENT

    Directory of Open Access Journals (Sweden)

    André Alexandrino Lotto

    2014-12-01

    Full Text Available This work aims to investigate the phosphorus removal by vacuum from metallurgical grade silicon (MGSi (98.5% to 99% Si. Melting experiments were carried out in a vacuum induction furnace, varying parameters such as temperature, time and relation area exposed to the vacuum / volume of molten silicon. The results of chemical analysis were obtained by inductively coupled plasma (ICP, and evaluated based on thermodynamic and kinetic aspects of the reaction of vaporization of the phosphorus in the silicon. The phosphorus was decreased from 33 to approximately 1.5 ppm after three hours of vacuum treatment, concluding that the evaporation step is the controlling step of the process for parameters of temperature, pressure and agitation used and refining by this process is technically feasible.

  5. 一种小天体软着陆中基于地表阴影区的跟踪算法%Method of tracking for soft landing on small body based on shadow areas

    Institute of Scientific and Technical Information of China (English)

    阮晓钢; 魏若岩; 李建更

    2014-01-01

    Considering the shadow areas of the planet surface can be seen as the landmark in the process of guidance, navigation and control(GNC) and hazard avoidance when the spacecraft soft lands on the small body, a method of the shadow areas tracking is proposed. Firstly, with the attitude estimates that are supplied by the attitude-measuring instruments, the two consecutive frames of image are rectified to the same attitude, and the shadow areas are detected by using the proposed binary algorithm. Then, the high correlation points of the shadow areas are found by using the template matching algorithm, and the feature vectors of the high correlation points are extracted to find the most similar point. Finally, the false matches are removed by using of random sample consensus(RANSAC). Two groups of sequence images of 433 Eros are utilized to teste the performance of the proposed method, and the results show that the method can be used in the real sequence images of planet.%考虑到星体表面的阴影区在航天器软着陆小天体时可作为导航路标以及壁障参考区,提出一种基于地表阴影区的跟踪算法。首先利用状态参数将拍摄到的前后两帧图像矫正到相同的状态,根据提出的二值化算法对图像的阴影区进行检测;然后利用模板匹配找出阴影区的相关位置点,并通过特征向量法找到相似性最大的位置点;最后结合RANSAC算法去除错匹配对。以两组433 Eros的连续拍摄图像作为阴影区进行跟踪实验,结果表明该算法具有一定的可行性。

  6. First testbeam results of prototype modules for the upgrade of the ATLAS strip tracking detector

    CERN Document Server

    Kuehn, Susanne; The ATLAS collaboration

    2016-01-01

    The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential of the LHC through a sizeable increase in the luminosity, totalling 1x1035cm-2s-1 after 10 years of operation. A consequence of this increased luminosity is the expected radiation damage at a integrated luminosity of 3000fb-1, requiring the tracking detectors to withstand hadron equivalences to over 1x1016 1 MeV neutron equivalent per cm2. With the addition of increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk), which will consist of both strip and pixellated silicon detectors. The silicon strip tracker exploits the concept of modularity. Fast readout electronics, deploying 130nm CMOS front-end electronics is glued on top of a silicon sensor. These so-called modules are glued on carbon structures and will span about 200m2 of active area. A broad R&D program is ongoing to develop and prototype many detector components. The modu...

  7. The PHOBOS silicon pad sensors

    International Nuclear Information System (INIS)

    PHOBOS is one of the four experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. PHOBOS utilizes silicon sensors to measure charged particle multiplicity distributions and to track particles in a 2-arm spectrometer. The detector consists of 450 silicon pad sensors. Nine different pad geometries are used to match the different physics needs of the experiment. A relatively high granularity, of up to 1536 channels per sensor, is used in the spectrometer. The multiplicity detector uses 128 and 64 channel sensors and the charge deposition per pad is measured to determine the multiplicity of single events. All sensors are of the double-metal silicon pad type with pad sizes from 1 up to 4 cm2. They are produced in Taiwan by the ERSO foundry under supervision of Miracle Co. and National Central University. An extensive testing procedure makes it possible to select sensors suited for use in PHOBOS. Detector modules consisting of up to 5 sensors are read out with integrated chips of either 64 or 128 channels. The test results of the sensors and the performance of the assembled detector modules are discussed

  8. Status of the CDF silicon detector

    Energy Technology Data Exchange (ETDEWEB)

    Grinstein, Sebastian; /Harvard U.

    2006-05-01

    The CDF Run II silicon micro-strip detector is an essential part of the heavy flavor tagging and forward tracking capabilities of the experiment. Since the commissioning period ended in 2002, about 85% of the 730 k readout channels have been consistently provided good data. A summary of the recent improvements in the DAQ system as well as experience of maintaining and operating such a large, complex detector are presented.

  9. Concentrator silicon cell research

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A.; Wenham, S.R.; Zhang, F.; Zhao, J.; Wang, A. [New South Wales Univ., Kensington (Australia). Solar Photovoltaic Lab.

    1992-04-01

    This project continued the developments of high-efficiency silicon concentrator solar cells with the goal of achieving a cell efficiency in the 26 to 27 percent range at a concentration level of 150 suns of greater. The target efficiency was achieved with the new PERL (passivated emitter, rear locally diffused) cell structure, but only at low concentration levels around 20 suns. The PERL structure combines oxide passivation of both top and rear surfaces of the cells with small area contact to heavily doped regions on the top and rear surfaces. Efficiency in the 22 to 23 percent range was also demonstrated for large-area concentrator cells fabricated with the buried contact solar cell processing sequence, either when combined with prismatic covers or with other innovative approaches to reduce top contact shadowing. 19 refs.

  10. Forward tracking detectors

    Indian Academy of Sciences (India)

    Klaus Mönig

    2007-11-01

    Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  11. Geo Issue Tracking System

    Science.gov (United States)

    Khakpour, Mohammad; Paulik, Christoph; Hahn, Sebastian

    2016-04-01

    Communication about remote sensing data quality between data providers and users as well as between the users is often difficult. The users have a hard time figuring out if a product has known problems over their region of interest and data providers have to spend a lot of effort to make this information available, if it exists. Scientific publications are one tool for communicating with the users base but they are static and mostly one way. As a data provider it is also often difficult to make feedback, received from users, available to the complete user base. The Geo Issue Tracking System (GeoITS) is an Open Source Web Application which has been developed to mitigate these problems. GeoITS combines a mapping interface (Google Maps) with a simple wiki platform. It allows users to give region specific feedback on a remote sensing product by drawing a polygon on the map and describing the problems they had using the remote sensing product in this area. These geolocated wiki entries are then viewable by other users as well as the data providers which can modify and extend the entries. In this way the conversations between the users and the data provider are no longer hidden in e.g. emails but open for all users of the dataset. This new kind of communication platform can enable better cooperation between users and data providers. It will also provide data providers with the ability to track problems their dataset might have in certain areas and resolve them with new product releases. The source code is available via http://github.com/TUW-GEO/geoits_dev A running instance can be tried at https://geoits.herokuapp.com/

  12. Economic Tracking Portfolios

    OpenAIRE

    Owen Lamont

    1999-01-01

    An economic tracking portfolio is a portfolio of assets with returns that track an economic variable. Monthly returns on stocks and bonds are useful in forecasting post-war US output, consumption, labor income, inflation, stock returns, bond returns, and Treasury bill returns. These forecasting relationships define portfolios that track market expectations about future economic variables. Using tracking portfolio returns as instruments for future economic variables substantially raises the es...

  13. The Apparent Contact Angle and Wetted Area of Active Alloys on Silicon Carbide as a Function of the Temperature and the Surface Roughness: A Multivariate Approach

    Science.gov (United States)

    Tillmann, Wolfgang; Pfeiffer, Jan; Wojarski, Lukas

    2015-08-01

    Despite the broad field of applications for active filler alloys for brazing ceramics, as well as intense research work on the wetting and spreading behavior of these alloys on ceramic surfaces within the last decades, the manufactured joints still exhibit significant variations in their properties due to the high sensitivity of the alloys to changing brazing conditions. This increases the need for investigations of the wetting and spreading behavior of filler alloys with regard to the dominating influences combined with their interdependencies, instead of solely focusing on single parameter investigations. In this regard, measurements of the wetting angle and area were conducted at solidified AgCuTi and CuSnTi alloys on SiC substrates. Based on these measurements, a regression model was generated, illustrating the influence of the brazing temperature, the roughness of the faying surfaces, the furnace atmosphere, and their interdependencies on the wetting and spreading behavior of the filler alloys. It was revealed that the behavior of the melts was significantly influenced by the varied brazing parameters, as well as by their interdependencies. This result was also predicted by the developed model and showed a high accuracy.

  14. Double Tracks closure report

    International Nuclear Information System (INIS)

    This report describes the remediation activities performed and the results of postremediation radiation surveys conducted at the Double Tracks site, located on Range 71 North, of the Nellis Air Force Range (NAFR) in southern Nevada. This remediation was conducted from June to August 1996 in accordance with the Interim Corrective Action Plan (ICAP) to remediate the site to an acceptable risk to human health and the environment. Soil with a total transuranic activity greater than 200 picoCuries per gram (pCi/g) was excavated, shipped to the Nevada Test Site (NTS), and disposed at the Area 3 Radioactive Waste Management Site (RWMS). A total of 52.3 grams of plutonium (Pu) with an activity of 5.12 Curies was disposed. The concrete pad at ground zero (GZ) was broken up, placed in a Sealand reg-sign container, and shipped to the NTS Area 6 decontamination pad. Additionally, approximately 10 m3 (350 ft3) of soil containing small chips of concrete was shipped to the NTS Area 6 decontamination pad. The concrete and soil/concrete mixture will be further characterized prior to disposal. At the time this report was written, characterization samples were being collected, with analytical results expected in January 1997. It is anticipated that the material will be disposed in mid-1997. This remediation is an interim action because final cleanup levels have not been established

  15. Real Time Eye Tracking in Unconstrained Environments

    Directory of Open Access Journals (Sweden)

    Majid Tajeri

    2012-07-01

    Full Text Available In this paper, an effective method for human eye tracking and also decreasing the current challenges and problems in its algorithms, possibly as real time and for unconstrained environments has been proposed. In this method, firstly face has been detected and segmented from the remaining parts to make the searching area in tracking stage, narrower and processing speed higher. Then eye area is determined and eye pupils are detected in the specified area. In the proposed method, to support tracking in eye occlusion state, corner detection has been additionally used. Experimental results show the potential of this method for real time eye tracking in unconstrained environments with existence of complex background, head and face rotation, beard, makeup, eye glasses and veil, even while the eyes are closed. The correct recognition rate of the proposed method is about 91.9%.

  16. First performance results of the Phobos silicon detectors

    International Nuclear Information System (INIS)

    The Phobos experiment concluded its first year of operation at RHIC taking data in Au-Au nucleus collisions at s radical = 65 GeV and 130 GeV/nucleon pair. First preliminary results of the performances of our silicon detectors in the experiment are summarized. The Phobos experiment uses silicon pad detectors for both tracking and multiplicity measurements. The silicon sensors vary strongly in their pad geometry. In this paper, we compare the signal response, the signal uniformity and signal-to-noise performance as measured in the experiment for the different geometries. Additionally, we investigate effects of very high channel occupancy on the signal response

  17. First performance results of the Phobos silicon detectors

    Science.gov (United States)

    Pernegger, H.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hołyński, R.; Hofman, D. J.; Holzman, B.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Lin, W. T.; Manly, S.; McLeod, D.; Michalowski, J.; Mignerey, A.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Stephans, G. S. F.; Steinberg, P.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2001-11-01

    The Phobos experiment concluded its first year of operation at RHIC taking data in Au-Au nucleus collisions at s nn=65 GeV and 130 GeV/ nucleon pair. First preliminary results of the performances of our silicon detectors in the experiment are summarized. The Phobos experiment uses silicon pad detectors for both tracking and multiplicity measurements. The silicon sensors vary strongly in their pad geometry. In this paper, we compare the signal response, the signal uniformity and signal-to-noise performance as measured in the experiment for the different geometries. Additionally, we investigate effects of very high channel occupancy on the signal response.

  18. Advanced Tracking of Vehicles

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Li, K.-J.; Pakalnis, Stardas;

    2005-01-01

    server-side updates. This is achieved by designing, prototyping, and testing novel tracking techniques that exploit knowledge of the road network and past movement. These resulting tracking techniques are to support mobile services that rely on the existence of a central server that continuously tracks...

  19. APPLICATION FOR AIRCRAFT TRACKING

    OpenAIRE

    Ostroumov, Ivan; Kuz’menko, Natalia

    2011-01-01

    Abstract. In the article the important problems of software development for aircraft tracking have beendiscussed. Position reports of ACARS have been used for aircraft tracking around the world.An algorithm of aircraft coordinates decoding and visualization of aircraft position on the map has beenrepresented.Keywords: ACARS, aircraft, internet, position, software, tracking.

  20. Track and Field Facilities.

    Science.gov (United States)

    Wood, Tony

    2001-01-01

    Discusses planning and design tips that help ensure track and field facilities are successful and well-suited to both school and community use. Examines approaches to determining the best track surface and ways to maximize track and field flexibility with limited space. (GR)

  1. Silicon sensors for trackers at high-luminosity environment

    International Nuclear Information System (INIS)

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

  2. Silicon sensors for trackers at high-luminosity environment

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-01

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

  3. ESSenTIAL: EPIXfab services specifically targeting (SME) industrial takeup of advanced silicon photonics

    NARCIS (Netherlands)

    Pozo Torres, J.M.; Kumar, P.; Lo Cascio, D.M.R.; Khanna, A.; Dumon, P.; Delbeke, D.; Baets, R.; Fournier, M.; Fedeli, J.-M.; Fulbert, L.; Zimmermann, L.; Tillack, B.; Tian, H.; Aalto, T.; O'Brien, P.; Deptuck, D.; Xu, J.; Zhang, X.; Gale, D.

    2012-01-01

    ePIXfab brings silicon photonics within reach of European small and medium sized enterprises, thereby building on its track record and its integration into Europractice. To this end, ePIXfab offers affordable access to standardized active and passive silicon photonic IC and packaging technology, a p

  4. Descent of the Silicon Pixel Detector (SPD) for ALICE Experiment

    CERN Multimedia

    2007-01-01

    The Silicon Pixel Detector (SPD) constitutes the two innermost layers of the ALICE Inner Tracking System (ITS) at radii of 3.9 cm and 7.6 cm, respectively. It is a fundamental element for the determination of the position of the primary vertex as well as for the measurement of the impact parameter of secondary tracks originating from the weak decays of strange, charm and beauty particles.

  5. Explore new eye tracking and gaze locating methods

    OpenAIRE

    Kadyrov, Alexander; Yu, Hui; Liu, Honghai

    2013-01-01

    Eye tracking has been used extensively in research, often for plotting the gaze location of research participants. Many of the existing methods on tracking gaze locations, however, require special equipment. This equipment can be very expensive and/or cumbersome to use, restricting the use of it to specialist labs. By producing a method of eye tracking which requires minimal equipment and set up time, eye tracking might be more widely used as a research tool, especially in exploratory areas w...

  6. The CDF Silicon Vertex Detector for Run II

    Energy Technology Data Exchange (ETDEWEB)

    R. Rossin

    2004-01-06

    The 8 layer, 720k channel CDF Run II silicon detector is an essential part of the heavy flavor tagging and forward tracking capabilities of the CDF experiment. A summary of the experience in commissioning and operating this double-sided detector during the first 2 years of Run II is presented. The performances of the silicon in term of resolution, efficiency are also described. The results of the studies of radiation damage and the expected operational limits are discussed. A short description of the SVT, the Level 2 Silicon Vertex Trigger, one of the major upgrades related to the new silicon device is also presented. Finally, some of the many physics results achieved by means of the new Silicon+SVT machinery are also reviewed.

  7. Black luminescent silicon

    Energy Technology Data Exchange (ETDEWEB)

    Pezoldt, Joerg [FG Nanotechnologie, Institut fuer Mikro- und Nanotechnologie, TU Ilmenau, Postfach 100565, 98684 Ilmenau (Germany); Kups, Thomas [FG Werkstoffe der Elektrotechnik, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 1005765, 98684 Ilmenau (Germany); Stubenrauch, Mike [FG Mikromechanische Systeme, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 1005765, 98684 Ilmenau (Germany); Fischer, Michael [FG Elektroniktechnologie, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 1005765, 98684 Ilmenau (Germany)

    2011-03-15

    Black silicon is a fascinating multipurpose modification of bulk silicon which can be fabricated in a selforganized structure formation process during dry etching of bare silicon wafer leading to the formation of a high density of silicon needles. The smallest dimension of the tips approaches values between 1 and 2 nm. The silicon nanostructure exhibits an extremely low diffuse reflectivity. The nanosized tips and their coating with fluorine doped nonstoichiometric silicon dioxide are responsible for cathodoluminescence in the blue-green and red regions of the visible spectra (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. 4H silicon carbide particle detectors: study of the defects induced by high energy neutron irradiation

    OpenAIRE

    Fabbri, Filippo

    2008-01-01

    During the last decade advances in the field of sensor design and improved base materials have pushed the radiation hardness of the current silicon detector technology to impressive performance. It should allow operation of the tracking systems of the Large Hadron Collider (LHC) experiments at nominal luminosity (1034 cm-2s-1) for about 10 years. The current silicon detectors are unable to cope with such an environment. Silicon carbide (SiC), which has recently been recognized ...

  9. Porous siliconformation and etching process for use in silicon micromachining

    Science.gov (United States)

    Guilinger, Terry R.; Kelly, Michael J.; Martin, Jr., Samuel B.; Stevenson, Joel O.; Tsao, Sylvia S.

    1991-01-01

    A reproducible process for uniformly etching silicon from a series of micromechanical structures used in electrical devices and the like includes providing a micromechanical structure having a silicon layer with defined areas for removal thereon and an electrochemical cell containing an aqueous hydrofluoric acid electrolyte. The micromechanical structure is submerged in the electrochemical cell and the defined areas of the silicon layer thereon are anodically biased by passing a current through the electrochemical cell for a time period sufficient to cause the defined areas of the silicon layer to become porous. The formation of the depth of the porous silicon is regulated by controlling the amount of current passing through the electrochemical cell. The micromechanical structure is then removed from the electrochemical cell and submerged in a hydroxide solution to remove the porous silicon. The process is subsequently repeated for each of the series of micromechanical structures to achieve a reproducibility better than 0.3%.

  10. Micromachined three-dimensional electrode arrays for transcutaneous nerve tracking

    International Nuclear Information System (INIS)

    We report the development of metal transfer micromolded (MTM) three-dimensional microelectrode arrays (3D MEAs) for a transcutaneous nerve tracking application. The measurements of electrode–skin–electrode impedance (ESEI), electromyography (EMG) and nerve conduction utilizing these minimally invasive 3D MEAs are demonstrated in this paper. The 3D MEAs used in these measurements consist of a metalized micro-tower array that can penetrate the outer layers of the skin in a painless fashion and are fabricated using MTM technology. Two techniques, an inclined UV lithography approach and a double-side exposure of thick negative tone resist, have been developed to fabricate the 3D MEA master structure. The MEAs themselves are fabricated from the master structure utilizing micromolding techniques. Metal patterns are transferred during the micromolding process, thereby ensuring reduced process steps compared to traditional silicon-based approaches. These 3D MEAs have been packaged utilizing biocompatible Kapton® substrates. ESEI measurements have been carried out on test human subjects with standard commercial wet electrodes as a reference. The 3D MEAs demonstrate an order of magnitude lower ESEI (normalized to area) compared to wet electrodes for an area that is 12.56 times smaller. This compares well with other demonstrated approaches in literature. For a nerve tracking demonstration, we have chosen EMG and nerve conduction measurements on test human subjects. The 3D MEAs show 100% improvement in signal power and SNR/√area as compared to standard electrodes. They also demonstrate larger amplitude signals and faster rise times during nerve conduction measurements. We believe that this microfabrication and packaging approach scales well to large-area, high-density arrays required for applications like nerve tracking. This development will increase the stimulation and recording fidelity of skin surface electrodes, while increasing their spatial resolution by an order

  11. Bayesian multiple target tracking

    CERN Document Server

    Streit, Roy L

    2013-01-01

    This second edition has undergone substantial revision from the 1999 first edition, recognizing that a lot has changed in the multiple target tracking field. One of the most dramatic changes is in the widespread use of particle filters to implement nonlinear, non-Gaussian Bayesian trackers. This book views multiple target tracking as a Bayesian inference problem. Within this framework it develops the theory of single target tracking, multiple target tracking, and likelihood ratio detection and tracking. In addition to providing a detailed description of a basic particle filter that implements

  12. Wettability and silicone hydrogel lenses: a review.

    Science.gov (United States)

    Keir, Nancy; Jones, Lyndon

    2013-01-01

    One of the major breakthroughs in the development of silicone hydrogel contact lenses has related to the ability of manufacturers to overcome the surface hydrophobicity that occurred with silicone elastomer lenses. However, the wettability of silicone hydrogel lenses continues to be of interest as a potential link between in vivo lens performance and contact lens-related comfort. This article will review some of the knowledge we have gained in the area of contact lens wettability over the past decade and will discuss some of the challenges related to its measurement. PMID:23274760

  13. Transistors using crystalline silicon devices on glass

    Science.gov (United States)

    McCarthy, Anthony M.

    1995-01-01

    A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

  14. Tracking by Neural Nets

    CERN Document Server

    Jofrehei, Arash

    2015-01-01

    Current track reconstruction methods start with two points and then for each layer loop through all possible hits to find proper hits to add to that track. Another idea would be to use this large number of already reconstructed events and/or simulated data and train a machine on this data to find tracks given hit pixels. Training time could be long but real time tracking is really fast. Simulation might not be as realistic as real data but tracking efficiency is 100 percent for that while by using real data we would probably be limited to current efficiency. The fact that this approach can be a lot faster and even more efficient than current methods by using simulation data can make it a great alternative for current track reconstruction methods used in both triggering and tracking.

  15. Smart Vehicle Tracking System

    Directory of Open Access Journals (Sweden)

    K.P.Kamble

    2012-08-01

    Full Text Available It is amazing to know how simple ideas can give a whole new dimension to the tracking and navigation industry and smart vehicle tracking system is used for tracking the vehicles. You can optimize driver routes, save petrol or gas and time, reduce theft and control the vehicle functions. Many a times it is not required to track your vehicle or target globally. In majority of cases tracking is more restricted to local purposes only, such as tracking movement of vehicle within city, tracking the raw materials within industrial estate or to know the present position of your daughter or son within city. But unfortunately in the pursuit of making things complex this simple idea is forgotten. This simple yet powerful idea forms the basis of this revolutionary project. All this coupled with a very low cost, a robust design and tremendous market potential makes this model even more attractive.

  16. Radiation hard silicon microstrip detectors for use in ATLAS at CERN

    International Nuclear Information System (INIS)

    The Large Hadron Collider (LHC) at CERN (Geneva, Switzerland) will accelerate protons in colliding beams to a center of mass energy of 14 TeV at very high luminosities. The ATLAS detector is being built to explore the physics in this unprecedented energy range. Tracking of charged particles in high-energy physics (HEP) experiments requires a high spatial resolution and fast signal readout, all with as little material as possible. Silicon microstrip detectors meet these requirements well and have been chosen for the Semiconductor Tracker (SCT) which is part of the inner tracking system of ATLAS and has a total area of 61 m2. During the 10 years of operation at LHC, the total fluence received by the detectors is sufficiently large that they will suffer a severe degradation from radiation induced damage. The damage affects both the physics performance of the detectors as well as their operability and a great challenge has been to develop radiation hard detectors for this environment. An extensive irradiation programme has been carried out where detectors of various designs, including defect engineering by oxygen enriched silicon, have been irradiated to the expected fluence. A subsequent thermal annealing period is included to account for a realistic annual maintenance schedule at room temperature, during which the radiation induced defects alter the detector properties significantly. This thesis presents work that has been carried out in the Bergen ATLAS group with results both from the irradiation programme and from detector testing during the module production. (Author)

  17. Radiation hard silicon microstrip detectors for use in ATLAS at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Lars Gimmestad

    2005-07-01

    The Large Hadron Collider (LHC) at CERN (Geneva, Switzerland) will accelerate protons in colliding beams to a center of mass energy of 14 TeV at very high luminosities. The ATLAS detector is being built to explore the physics in this unprecedented energy range. Tracking of charged particles in high-energy physics (HEP) experiments requires a high spatial resolution and fast signal readout, all with as little material as possible. Silicon microstrip detectors meet these requirements well and have been chosen for the Semiconductor Tracker (SCT) which is part of the inner tracking system of ATLAS and has a total area of 61 m2. During the 10 years of operation at LHC, the total fluence received by the detectors is sufficiently large that they will suffer a severe degradation from radiation induced damage. The damage affects both the physics performance of the detectors as well as their operability and a great challenge has been to develop radiation hard detectors for this environment. An extensive irradiation programme has been carried out where detectors of various designs, including defect engineering by oxygen enriched silicon, have been irradiated to the expected fluence. A subsequent thermal annealing period is included to account for a realistic annual maintenance schedule at room temperature, during which the radiation induced defects alter the detector properties significantly. This thesis presents work that has been carried out in the Bergen ATLAS group with results both from the irradiation programme and from detector testing during the module production. (Author)

  18. Tracks: Nurses and the Tracking Network

    Centers for Disease Control (CDC) Podcasts

    2012-06-06

    This podcast highlights the utility of the National Environmental Public Health Tracking Network for nurses in a variety of work settings. It features commentary from the American Nurses Association and includes stories from a public health nurse in Massachusetts.  Created: 6/6/2012 by National Center for Environmental Health (NCEH)/Division of Environmental Hazards and Health Effects (DEHHE)/Environmental Health Tracking Branch (EHTB).   Date Released: 6/6/2012.

  19. Kalman Filter Based Railway Tracking from Mobile LIDAR Data

    Science.gov (United States)

    Jwa, Y.; Sonh, G.

    2015-08-01

    This study introduces a new method to reconstruct 3D model of railway tracks from a railway corridor scene captured by mobile LiDAR data. The proposed approach starts to approximate the orientation of railway track trajectory from LiDAR point clouds and extract a strip, which direction is orthogonal to the trajectory of railway track. Within the strip, a track region and its track points are detected based on the Bayesian decision process. Once the main track region is localized, rail head points are segmented based on the region growing approach from the detected track points and then initial track models are reconstructed using a third-degree polynomial function. Based on the initial modelling result, a potential track region with varying lengths is dynamically predicted and the model parameters are updated in the Kalman Filter framework. The key aspect is that the proposed approach is able to enhance the efficiency of the railway tracking process by reducing the complexity for detecting track points and reconstructing track models based on the use of the track model previously reconstructed. An evaluation of the proposed method is performed over an urban railway corridor area containing multiple railway track pairs.

  20. Alignment procedures for the CMS silicon tracker

    CERN Document Server

    Behr, Joerg

    2012-01-01

    The CMS all-silicon tracker consists of 16588 modules. Therefore its alignment procedures require sophisticated algorithms. Advanced tools of computing, tracking and data analysis have been deployed for reaching the targeted performance. Ultimate local precision is now achieved by the determination of sensor curvatures, challenging the algorithms to determine about 200k parameters simultaneously. Systematic biases in the geometry are controlled by adding further information into the alignment workflow, e.g. the mass of decaying resonances. The orientation of the tracker with respect to the magnetic field of CMS is determined with a stand-alone chi-square minimization procedure. The geometries are finally carefully validated. The monitored quantities include the basic track quantities for tracks from both collisions and cosmic muons and physics observables.

  1. Alignment procedures for the CMS silicon tracker

    International Nuclear Information System (INIS)

    The CMS all-silicon tracker consists of 16588 modules. Therefore its alignment procedures require sophisticated algorithms. Advanced tools of computing, tracking and data analysis have been deployed for reaching the targeted performance. Ultimate local precision is now achieved by the determination of sensor curvatures, challenging the algorithms to determine about 200k parameters simultaneously. Systematic biases in the geometry are controlled by adding further information into the alignment workflow, e.g. the mass of decaying resonances. The orientation of the tracker with respect to the magnetic field of CMS is determined with a stand-alone chi-square minimization procedure. The geometries are finally carefully validated. The monitored quantities include the basic track quantities for tracks from both collisions and cosmic muons and physics observables.

  2. High-Sensitivity X-ray Polarimetry with Amorphous Silicon Active-Matrix Pixel Proportional Counters

    Science.gov (United States)

    Black, J. K.; Deines-Jones, P.; Jahoda, K.; Ready, S. E.; Street, R. A.

    2003-01-01

    Photoelectric X-ray polarimeters based on pixel micropattern gas detectors (MPGDs) offer order-of-magnitude improvement in sensitivity over more traditional techniques based on X-ray scattering. This new technique places some of the most interesting astronomical observations within reach of even a small, dedicated mission. The most sensitive instrument would be a photoelectric polarimeter at the focus of 2 a very large mirror, such as the planned XEUS. Our efforts are focused on a smaller pathfinder mission, which would achieve its greatest sensitivity with large-area, low-background, collimated polarimeters. We have recently demonstrated a MPGD polarimeter using amorphous silicon thin-film transistor (TFT) readout suitable for the focal plane of an X-ray telescope. All the technologies used in the demonstration polarimeter are scalable to the areas required for a high-sensitivity collimated polarimeter. Leywords: X-ray polarimetry, particle tracking, proportional counter, GEM, pixel readout

  3. Bonding silicones with epoxies

    Energy Technology Data Exchange (ETDEWEB)

    Tira, J.S.

    1980-01-01

    It is shown that silicones, both room temperature vulcanizing (RTV) and millable rubber (press cured) can be successfully bonded to other materials using plasma treatment and epoxy adhesives. The plasma treatment using dry air atmosphere increases the surface energy of the silicone and thus provides a lower water contact angle. This phenomenon allows the epoxy adhesive to wet the silicone surface and ultimately bond. Bond strengths are sufficiently high to result in failures in the silicone materials rather than the adhesive bond.

  4. Intraventricular Silicone Oil

    OpenAIRE

    Mathis, Stéphane; Boissonnot, Michèle; Tasu, Jean-Pierre; Simonet, Charles; Ciron, Jonathan; Neau, Jean-Philippe

    2016-01-01

    Abstract Intracranial silicone oil is a rare complication of intraocular endotamponade with silicone oil. We describe a case of intraventricular silicone oil fortuitously observed 38 months after an intraocular tamponade for a complicated retinal detachment in an 82 year-old woman admitted in the Department of Neurology for a stroke. We confirm the migration of silicone oil along the optic nerve. We discuss this rare entity with a review of the few other cases reported in the medical literatu...

  5. Silicon: electrochemistry and luminescence

    OpenAIRE

    Kooij, Ernst Stefan

    2001-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible luminescence from porous silicon is investigated. Both under cathodic and anodic polarization emission can be observed in the presence of oxidizing and reducing agents, respectively. Also in indifferent electrol...

  6. Doping Silicon Wafers with Boron by Use of Silicon Paste

    Institute of Scientific and Technical Information of China (English)

    Yu Gao; Shu Zhou; Yunfan Zhang; Chen Dong; Xiaodong Pi; Deren Yang

    2013-01-01

    In this work we introduce recently developed silicon-paste-enabled p-type doping for silicon.Boron-doped silicon nanoparticles are synthesized by a plasma approach.They are then dispersed in solvents to form silicon paste.Silicon paste is screen-printed at the surface of silicon wafers.By annealing,boron atoms in silicon paste diffuse into silicon wafers.Chemical analysis is employed to obtain the concentrations of boron in silicon nanoparticles.The successful doping of silicon wafers with boron is evidenced by secondary ion mass spectroscopy (SIMS) and sheet resistance measurements.

  7. Silicon photonics: some remaining challenges

    Science.gov (United States)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  8. Silicon nanostructures for photonics

    International Nuclear Information System (INIS)

    Nanostructuring silicon is an effective way to turn silicon into a photonic material. In fact, low-dimensional silicon shows light amplification characteristics, non-linear optical effects, photon confinement in both one and two dimensions, photon trapping with evidence of light localization, and gas-sensing properties. (author)

  9. Silicon: electrochemistry and luminescence

    NARCIS (Netherlands)

    Kooij, Ernst Stefan

    2001-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible luminescenc

  10. Tracking dynamic team activity

    Energy Technology Data Exchange (ETDEWEB)

    Tambe, M. [Univ. of Southern California, Marina del Rey, CA (United States)

    1996-12-31

    AI researchers are striving to build complex multi-agent worlds with intended applications ranging from the RoboCup robotic soccer tournaments, to interactive virtual theatre, to large-scale real-world battlefield simulations. Agent tracking - monitoring other agent`s actions and inferring their higher-level goals and intentions - is a central requirement in such worlds. While previous work has mostly focused on tracking individual agents, this paper goes beyond by focusing on agent teams. Team tracking poses the challenge of tracking a team`s joint goals and plans. Dynamic, real-time environments add to the challenge, as ambiguities have to be resolved in real-time. The central hypothesis underlying the present work is that an explicit team-oriented perspective enables effective team tracking. This hypothesis is instantiated using the model tracing technology employed in tracking individual agents. Thus, to track team activities, team models are put to service. Team models are a concrete application of the joint intentions framework and enable an agent to track team activities, regardless of the agent`s being a collaborative participant or a non-participant in the team. To facilitate real-time ambiguity resolution with team models: (i) aspects of tracking are cast as constraint satisfaction problems to exploit constraint propagation techniques; and (ii) a cost minimality criterion is applied to constrain tracking search. Empirical results from two separate tasks in real-world, dynamic environments one collaborative and one competitive - are provided.

  11. Results from a beam test of silicon strip sensors manufactured by Infineon Technologies AG

    Energy Technology Data Exchange (ETDEWEB)

    Dragicevic, M., E-mail: marko.dragicevic@oeaw.ac.at [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Auzinger, G. [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); CERN, Geneva (Switzerland); Bartl, U. [Infineon Technologies Austria AG, Villach (Austria); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Gamerith, S.; Hacker, J. [Infineon Technologies Austria AG, Villach (Austria); König, A. [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Infineon Technologies Austria AG, Villach (Austria); Kröner, F.; Kucher, E.; Moser, J.; Neidhart, T. [Infineon Technologies Austria AG, Villach (Austria); Schulze, H.-J. [Infineon Technologies AG, Munich (Germany); Schustereder, W. [Infineon Technologies Austria AG, Villach (Austria); Treberspurg, W. [Institute of High Energy Physics, Austrian Academy of Sciences, Vienna (Austria); Wübben, T. [Infineon Technologies Austria AG, Villach (Austria)

    2014-11-21

    Most modern particle physics experiments use silicon based sensors for their tracking systems. These sensors are able to detect particles generated in high energy collisions with high spatial resolution and therefore allow the precise reconstruction of particle tracks. So far only a few vendors were capable of producing silicon strip sensors with the quality needed in particle physics experiments. Together with the European-based semiconductor manufacturer Infineon Technologies AG (Infineon) the Institute of High Energy Physics of the Austrian Academy of Sciences (HEPHY) developed planar silicon strip sensors in p-on-n technology. This work presents the first results from a beam test of strip sensors manufactured by Infineon.

  12. Results from a beam test of silicon strip sensors manufactured by Infineon Technologies AG

    CERN Document Server

    Dragicevic, M; Bartl, U; Bergauer, T; Gamerith, S; Hacker, J; König, A; Kröner, F; Kucher, E; Moser, J; Neidhart, T; Schulze, H-J; Schustereder, W; Treberspurg, W; Wübben, T

    2014-01-01

    Most modern particle physics experiments use silicon based sensors for their tracking systems. These sensors are able to detect particles generated in high energy collisions with high spatial resolution and therefore allow the precise reconstruction of particle tracks. So far only a few vendors were capable of producing silicon strip sensors with the quality needed in particle physics experiments. Together with the European-based semiconductor manufacturer Infineon Technologies AG (Infineon) the Institute of High Energy Physics of the Austrian Academy of Sciences (HEPHY) developed planar silicon strip sensors in p-on-n technology. This work presents the first results from a beam test of strip sensors manufactured by Infineon.

  13. Novel scintillators and silicon photomultipliers for nuclear physics and applications

    Science.gov (United States)

    Jenkins, David

    2015-06-01

    Until comparatively recently, scintillator detectors were seen as an old-fashioned tool of nuclear physics with more attention being given to areas such as gamma-ray tracking using high-purity germanium detectors. Next-generation scintillator detectors, such as lanthanum bromide, which were developed for the demands of space science and gamma- ray telescopes, are found to have strong applicability to low energy nuclear physics. Their excellent timing resolution makes them very suitable for fast timing measurements and their much improved energy resolution compared to conventional scintillators promises to open up new avenues in nuclear physics research which were presently hard to access. Such "medium-resolution" spectroscopy has broad interest across several areas of contemporary interest such as the study of nuclear giant resonances. In addition to the connections to space science, it is striking that the demands of contemporary medical imaging have strong overlap with those of experimental nuclear physics. An example is the interest in PET-MRI combined imaging which requires putting scintillator detectors in a high magnetic field environment. This has led to strong advances in the area of silicon photomultipliers, a solid-state replacement for photomultiplier tubes, which are insensitive to magnetic fields. Broad application to nuclear physics of this technology may be foreseen.

  14. Injuries in short track asphalt racing.

    Science.gov (United States)

    Busby, J D

    1978-10-01

    Stock car racing is a popular activity. Although spectators are seldom injured, drivers at short asphalt tracks often sustain minor injuries. The neck and the knee are the most commonly injured areas. Rigid safety requirements are essential and help to prevent serious injuries. Severe injuries occur on an average of once a year, but no fatalities have been recorded at one short track that has been studied for a six-year period. PMID:707264

  15. Multi-Pose Face Detection and Tracking Using Condensation

    Directory of Open Access Journals (Sweden)

    Cheng-Chieh Chiang

    2014-10-01

    Full Text Available Automatically locating face areas can advance applications either in images or videos. This paper proposes a video-based approach for face detection and tracking in an indoor environment to determine where face areas appear in video sequences. Our approach involves four main modules: an initialization module for setting all configurations, a Condensation module for face tracking, a template module for measuring the observation process in Condensation, and a correction module for correcting the tracking if the tracked face has been lost. We adapted the Condensation algorithm for dealing with the face tracking problem, and designed a checklist scheme for the template module that can record the most significant templates of the tracked face poses. We also performed experiments to demonstrate the performance and the robustness of our proposed approach for face detection and tracking.

  16. The chemistry of silicon

    CERN Document Server

    Rochow, E G; Emeléus, H J; Nyholm, Ronald

    1975-01-01

    Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

  17. Tracking fast neutrons

    International Nuclear Information System (INIS)

    Both neutron absorption and elastic scattering can be used to measure neutron momentum. Based on elastic collisions, the linear momentum of a fast neutron can be measured from as few as two consecutive recoil ion tracks plus the vertex position of the third collision, or ‘two and half’ ion tracks. If the time delay between the first two consecutive ion tracks is also measured, the number of ion tracks can be reduced to one and a half. The angular and magnitude resolutions are limited by ion range straggling to about 10%. Multi-wire proportional chambers and light-field imaging can be used for fast neutron tracking. Light-field imaging is free of charge-diffusion-induced image blur, but the limited number of photons available can be a challenge. 1H, 2H and 3He could be used for the initial development of fast neutron trackers based on light-field imaging. -- Highlights: • We describe the basic principle of fast neutron tracking through elastic collisions and absorption; • We calculate tracking errors, which are limited by ion range straggling. • Multi-wire proportional chamber and light field imaging are discussed for fast neutron tracking; • Time projection of ion tracks can be achieved by detecting photons

  18. Online Supervised Subspace Tracking

    OpenAIRE

    Xie, Yao; Song, Ruiyang; Dai, Hanjun; Li, Qingbin; Song, Le

    2015-01-01

    We present a framework for supervised subspace tracking, when there are two time series $x_t$ and $y_t$, one being the high-dimensional predictors and the other being the response variables and the subspace tracking needs to take into consideration of both sequences. It extends the classic online subspace tracking work which can be viewed as tracking of $x_t$ only. Our online sufficient dimensionality reduction (OSDR) is a meta-algorithm that can be applied to various cases including linear r...

  19. Tracking in anatomic pathology.

    Science.gov (United States)

    Pantanowitz, Liron; Mackinnon, Alexander C; Sinard, John H

    2013-12-01

    Bar code-based tracking solutions, long present in clinical pathology laboratories, have recently made an appearance in anatomic pathology (AP) laboratories. Tracking of AP "assets" (specimens, blocks, slides) can enhance laboratory efficiency, promote patient safety, and improve patient care. Routing of excess clinical material into research laboratories and biorepositories are other avenues that can benefit from tracking of AP assets. Implementing tracking is not as simple as installing software and turning it on. Not all tracking solutions are alike. Careful analysis of laboratory workflow is needed before implementing tracking to assure that this solution will meet the needs of the laboratory. Such analysis will likely uncover practices that may need to be modified before a tracking system can be deployed. Costs that go beyond simply that of purchasing software will be incurred and need to be considered in the budgeting process. Finally, people, not technology, are the key to assuring quality. Tracking will require significant changes in workflow and an overall change in the culture of the laboratory. Preparation, training, buy-in, and accountability of the people involved are crucial to the success of this process. This article reviews the benefits, available technology, underlying principles, and implementation of tracking solutions for the AP and research laboratory. PMID:23634908

  20. Chemical Analysis Methods for Silicon Carbide

    Institute of Scientific and Technical Information of China (English)

    Shen Keyin

    2006-01-01

    @@ 1 General and Scope This Standard specifies the determination method of silicon dioxide, free silicon, free carbon, total carbon, silicon carbide, ferric sesquioxide in silicon carbide abrasive material.

  1. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    Science.gov (United States)

    Hussain, Muhammad M.; Rojas, Jhonathan P.; Torres Sevilla, Galo A.

    2013-05-01

    Today's information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor - heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon - industry's darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%).

  2. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    KAUST Repository

    Hussain, Muhammad Mustafa

    2013-05-30

    Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  3. Ion-counting nanodosemeter with particle tracking capabilities.

    Science.gov (United States)

    Bashkirov, V; Schulte, R; Breskin, A; Chechik, R; Schemelinin, S; Garty, G; Wroe, A; Sadrozinski, H; Grosswendt, B

    2006-01-01

    An ion-counting nanodosemeter (ND) yielding the distribution of radiation-induced ions in a low-pressure gas within a millimetric, wall-less sensitive volume (SV) was equipped with a silicon microstrip telescope that tracks the primary particles, allowing correlation of nanodosimetric data with particle position relative to the SV. The performance of this tracking ND was tested with a broad 250 MeV proton beam at Loma Linda University Medical Center. The high-resolution tracking capability made it possible to map the ion registration efficiency distribution within the SV, for which only calculated data were available before. It was shown that tracking information combined with nanodosimetric data can map the ionisation pattern of track segments within 150 nm-equivalent long SVs with a longitudinal resolution of approximately 5 tissue-equivalent nanometers. Data acquired in this work were compared with results of Monte Carlo track structure simulations. The good agreement between 'tracking nanodosimetry' data acquired with the new system and simulated data supports the application of ion-counting nanodosimetry in experimental track-structure studies. PMID:17283009

  4. Design of a tracking system for a solenoidal detector

    International Nuclear Information System (INIS)

    The goals of a tracking system for the SSC are to provide momentum measurement and a fast trigger for charged particles with pT above a few GeV/c and |η| ≤ 2.5. In addition, the tracking system should provide a precise vertex measurement in order to identify long-lived tracks, for example, from B decays, and detect separated vertices from multiple p-p interactions. Since the tracking system is only a part of the complete detector, it must provide these functions in an economical manner. The tracking system must operate in the high-rate environment of the SSC at and above the design luminosity. The design of an integrated tracking system for a solenoidal detector will be presented. The tracking system consists of a silicon pixel and microstrip detector at smaller radii from the beam collision point and wire chambers at larger radii. The tracking system provides momentum measurements and a fast trigger for all charged particles with pT above a few GeV/c and for |η| ≤ 2.5. Research and development issues will be discussed

  5. Solution-processed polycrystalline silicon on paper

    Science.gov (United States)

    Trifunovic, M.; Shimoda, T.; Ishihara, R.

    2015-04-01

    Printing electronics has led to application areas which were formerly impossible with conventional electronic processes. Solutions are used as inks on top of large areas at room temperatures, allowing the production of fully flexible circuitry. Commonly, research in these inks have focused on organic and metal-oxide ink materials due to their printability, while these materials lack in the electronic performance when compared to silicon electronics. Silicon electronics, on the other hand, has only recently found their way in solution processes. Printing of cyclopentasilane as the silicon ink has been conducted and devices with far superior electric performance have been made when compared to other ink materials. A thermal annealing step of this material, however, was necessary, which prevented its usage on inexpensive substrates with a limited thermal budget. In this work, we introduce a method that allows polycrystalline silicon (poly-Si) production directly from the same liquid silicon ink using excimer laser irradiation. In this way, poly-Si could be formed directly on top of paper even with a single laser pulse. Using this method, poly-Si transistors were created at a maximum temperature of only 150 °C. This method allows silicon device formation on inexpensive, temperature sensitive substrates such as polyethylene terephthalate, polyethylene naphthalate or paper, which leads to applications that require low-cost but high-speed electronics.

  6. Solution-processed polycrystalline silicon on paper

    Energy Technology Data Exchange (ETDEWEB)

    Trifunovic, M.; Ishihara, R., E-mail: r.ishihara@tudelft.nl [Delft Institute for Microsystems and Nanoelectronics (DIMES), Delft University of Technology, Feldmannweg 17, 2628CT Delft (Netherlands); Shimoda, T. [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292 (Japan)

    2015-04-20

    Printing electronics has led to application areas which were formerly impossible with conventional electronic processes. Solutions are used as inks on top of large areas at room temperatures, allowing the production of fully flexible circuitry. Commonly, research in these inks have focused on organic and metal-oxide ink materials due to their printability, while these materials lack in the electronic performance when compared to silicon electronics. Silicon electronics, on the other hand, has only recently found their way in solution processes. Printing of cyclopentasilane as the silicon ink has been conducted and devices with far superior electric performance have been made when compared to other ink materials. A thermal annealing step of this material, however, was necessary, which prevented its usage on inexpensive substrates with a limited thermal budget. In this work, we introduce a method that allows polycrystalline silicon (poly-Si) production directly from the same liquid silicon ink using excimer laser irradiation. In this way, poly-Si could be formed directly on top of paper even with a single laser pulse. Using this method, poly-Si transistors were created at a maximum temperature of only 150 °C. This method allows silicon device formation on inexpensive, temperature sensitive substrates such as polyethylene terephthalate, polyethylene naphthalate or paper, which leads to applications that require low-cost but high-speed electronics.

  7. Solution-processed polycrystalline silicon on paper

    International Nuclear Information System (INIS)

    Printing electronics has led to application areas which were formerly impossible with conventional electronic processes. Solutions are used as inks on top of large areas at room temperatures, allowing the production of fully flexible circuitry. Commonly, research in these inks have focused on organic and metal-oxide ink materials due to their printability, while these materials lack in the electronic performance when compared to silicon electronics. Silicon electronics, on the other hand, has only recently found their way in solution processes. Printing of cyclopentasilane as the silicon ink has been conducted and devices with far superior electric performance have been made when compared to other ink materials. A thermal annealing step of this material, however, was necessary, which prevented its usage on inexpensive substrates with a limited thermal budget. In this work, we introduce a method that allows polycrystalline silicon (poly-Si) production directly from the same liquid silicon ink using excimer laser irradiation. In this way, poly-Si could be formed directly on top of paper even with a single laser pulse. Using this method, poly-Si transistors were created at a maximum temperature of only 150 °C. This method allows silicon device formation on inexpensive, temperature sensitive substrates such as polyethylene terephthalate, polyethylene naphthalate or paper, which leads to applications that require low-cost but high-speed electronics

  8. Sampling Artifacts from Conductive Silicone Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.

    2009-05-15

    We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

  9. Microstructure Control of Columnar-Grained Silicon Substrate Solidified from Silicon Melts Using Gas Pressure

    Directory of Open Access Journals (Sweden)

    Jun-Kyu Lee

    2015-01-01

    Full Text Available A silicon substrate with the dimensions of 100 × 140 × 0.3 mm was grown directly from liquid silicon with gas pressure. The silicon melt in the sealed melting part was injected into the growth part at applied pressure of 780–850 Torr. The solidified silicon substrate was then transferred by the pull of the cooled dummy bar. A desirable structure with a liquid-solid interface perpendicular to the pulling direction was formed when the mold temperature in the solidification zone of the growth part was much higher than that of the dummy bar, as this technique should be able to overcome thermal loss through the molds and the limited heat flux derived from the very narrow contact area between the silicon melt and the dummy bar. In addition, because the metallic impurities and expansion of volume during solidification are preferably moved to a liquid phase, a high-quality silicon substrate, without defects such as cracks and impurities in the substrate, could be manufactured in the interface structure. The present study reports the experimental findings on a new and direct growth system for obtaining silicon substrates characterized by high quality and productivity, as a candidate for alternate routes for the fabrication of silicon substrates.

  10. A probabilistic analysis of silicon cost

    Science.gov (United States)

    Reiter, L. J.

    1983-01-01

    Silicon materials costs represent both a cost driver and an area where improvement can be made in the manufacture of photovoltaic modules. The cost from three processes for the production of low-cost silicon being developed under the U.S. Department of Energy's (DOE) National Photovoltaic Program is analyzed. The approach is based on probabilistic inputs and makes use of two models developed at the Jet Propulsion Laboratory: SIMRAND (SIMulation of Research ANd Development) and IPEG (Improved Price Estimating Guidelines). The approach, assumptions, and limitations are detailed along with a verification of the cost analyses methodology. Results, presented in the form of cumulative probability distributions for silicon cost, indicate that there is a 55% chance of reaching the DOE target of $16/kg for silicon material. This is a technically achievable cost based on expert forecasts of the results of ongoing research and development and do not imply any market prices for a given year.

  11. Tunable silicon CROW delay lines

    Science.gov (United States)

    Morichetti, Francesco; Canciamilla, Antonio; Torregiani, Matteo; Ferrari, Carlo; Melloni, Andrea; Martinelli, Mario

    2010-05-01

    Tunable coupled resonator optical waveguides (CROWs) are powerful and versatile devices that can be used to dynamically control the delay of optical data streams on chip. In this contribution we show that CROW delay lines fabricated on a silicon on insulator (SOI) platform are suitable for applications in the emerging scenario of optical systems at 100 Gbit/s. Issues concerning technology, design, limits and applications of SOI CROWs are discussed. The performances of silicon CROW delay lines activated by thermal tuning are compared to those of glass CROW in terms of power consumption, thermal crosstalk and reconfiguration speed. The continuous delay of 10-ps long optical pulses by 8 bit length is demonstrated by using a silicon CROW with a bandwidth of 87 GHz and made of 12 RRs. At 100 Gbit/s this structure provides comparable figures of merit (fractional delay of 0.75 bit/RR and fractional loss of 0.7 dB per bit-delay) of state-of-the art glass CROW operating at 10 Gbit/s, yet the area of the latter being three order of magnitude larger. The compatibility of silicon CROW with the emerging 100 Gbit/s systems is demonstrated by showing error-free phase-preserving propagation of a 100 Gbit/s return-to-zero (RZ) polarization-division-multiplexing (PolDM) differential quaternary phase shit keying (DQPSK) signal dynamically delayed by the CROW. It is also demonstrated that a silicon CROW can be used in a PolDM system to introduce a polarization selective delay in order to optimize the time interleaving of the two orthogonally polarized data streams.

  12. The Motif Tracking Algorithm

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The search for patterns or motifs in data represents a problem area of key interest to finance and economic researchers. In this paper, we introduce the motif tracking algorithm (MTA), a novel immune inspired (IS) pattern identification tool that is able to identify unknown motifs of a non specified length which repeat within time series data. The power of the algorithm comes from the fact that it uses a small number of parameters with minimal assumptions regarding the data being examined or the underlying motifs. Our interest lies in applying the algorithm to financial time series data to identify unknown patterns that exist. The algorithm is tested using three separate data sets. Particular suitability to financial data is shown by applying it to oil price data. In all cases, the algorithm identifies the presence of a motif population in a fast and efficient manner due to the utilization of an intuitive symbolic representation.The resulting population of motifs is shown to have considerable potential value for other applications such as forecasting and algorithm seeding.

  13. The Motif Tracking Algorithm

    CERN Document Server

    Wilson, William; Aickelin, Uwe; 10.1007/s11633.008.0032.0

    2010-01-01

    The search for patterns or motifs in data represents a problem area of key interest to finance and economic researchers. In this paper we introduce the Motif Tracking Algorithm, a novel immune inspired pattern identification tool that is able to identify unknown motifs of a non specified length which repeat within time series data. The power of the algorithm comes from the fact that it uses a small number of parameters with minimal assumptions regarding the data being examined or the underlying motifs. Our interest lies in applying the algorithm to financial time series data to identify unknown patterns that exist. The algorithm is tested using three separate data sets. Particular suitability to financial data is shown by applying it to oil price data. In all cases the algorithm identifies the presence of a motif population in a fast and efficient manner due to the utilisation of an intuitive symbolic representation. The resulting population of motifs is shown to have considerable potential value for other ap...

  14. D0 Silicon Upgrade: D0 Silicon Cooling System

    International Nuclear Information System (INIS)

    The cooling system design is not complete. This paper lays out the general design and some of the design calculations that have been performed up to this date. Further refinement will be performed. This is especially true in the piping layout, piping insulation and detector manifold areas. The silicon detector is cooled by means of a coolant in the beryllium channels that also act as the primary supporting device for the silicon ladders and wedges. The coolant is water with ethylene glycol added as a freezing point depressant. The glycol concentration in the coolant is 30% by weight resulting in a freezing point of approximately -15 C. If the water/glycol is not sufficient for maintaining the desired detector temperature the concentration of the water/glycol may be changed or an alternative coolant may be used.

  15. Silicon Sheet Growth Development for the Large Area Sheet Task of the Low Cost Solar Array Project. Heat Exchanger Method - Ingot Casting Fixed Abrasive Method - Multi-Wire Slicing

    Science.gov (United States)

    Schmid, F.; Khattak, C. P.

    1978-01-01

    Solar cells fabricated from HEM cast silicon yielded up to 15% conversion efficiencies. This was achieved in spite of using unpurified graphite parts in the HEM furnace and without optimization of material or cell processing parameters. Molybdenum retainers prevented SiC formation and reduced carbon content by 50%. The oxygen content of vacuum cast HEM silicon is lower than typical Czochralski grown silicon. Impregnation of 45 micrometers diamonds into 7.5 micrometers copper sheath showed distortion of the copper layer. However, 12.5 micrometers and 15 micrometers copper sheath can be impregnated with 45 micrometers diamonds to a high concentration. Electroless nickel plating of wires impregnated only in the cutting edge showed nickel concentration around the diamonds. This has the possibility of reducing kerf. The high speed slicer fabricated can achieve higher speed and longer stroke with vibration isolation.

  16. Characterization of double sided silicon micro-strip sensors with a pulsed infra-red laser system for the CBM experiment

    International Nuclear Information System (INIS)

    The Silicon Tracking System (STS) of the Compressed Baryonic Matter (CBM) experiment at FAIR is composed of 8 tracking stations consisting of 1292 double sided silicon micro-strip sensors. For the sensor development and for the quality assurance of produced sensors a laser test system has been built up. The aim of the sensor scans with the pulsed infra-red laser system is to determine the charge sharing between strips and to measure the uniformity of the sensor response over the whole active area. The prototype sensors tested with the laser system so far have 256 strips with a pitch of 50 μm on each side. They are read out by the self-triggering n-XYTER prototype read-out electronics. The laser system measures the sensor response in an automatized procedure at several thousand positions across the sensor with focussed infra-red laser light (σspotsize∼15 μm, λ=1060 nm). The duration (∝5ns) and power (few mW) of the laser pulses is selected such, that the absorption of the laser light in the 300 μm thick silicon sensors produces a number of about 24k electrons, which is similar to the charge created by minimum ionizing particles in these sensors. Results of laser scans for different sensors are presented.

  17. Eye-Tracking

    Directory of Open Access Journals (Sweden)

    Gabriela GROSSECK

    2006-01-01

    Full Text Available Eye-tracking: one of the newest and most efficient methods of improving on-line marketing communication is called eye-tracking. Marketers have borrowed this technique, usually used in psychological and medical research, in order to study web users with the help of a video camera incorporated in the monitor.

  18. Why we are tracking

    DEFF Research Database (Denmark)

    Tække, Jesper

    2015-01-01

    In this short essay, concerning why we are tracking, I will try to frame tracking as an evolutionary developed skill that humans need to survive. From an evolutionary point zero life must reflect upon itself in regard to its surrounding world as a kind of societal self-synchronization in this...

  19. Photon track evolution

    International Nuclear Information System (INIS)

    Given the time scale of biological, biochemical, biophysical and physical effects in a radiation exposure of living tissue, the first physical stage can be considered to be independent of time. All the physical interactions caused by the incident photons happen at the same starting time. From this point of view it would seem that the evolution of photon tracks is not a relevant topic for analysis; however, if the photon track is considered as a sequence of several interactions, there are several steps until the total degradation of the energy of the primary photon. We can characterise the photon track structure by the probability p(E,j), that is, the probability that a photon with energy E suffers j secondary interactions. The aim of this work is to analyse the photon track structure by considering j as a step of the photon track evolution towards the total degradation of the photon energy. Low energy photons (<150 keV) are considered, with water phantoms and half-extended geometry. The photon track evolution concept is presented and compared with the energy deposition along the track and also with the spatial distribution of the several steps in the photon track. (authors)

  20. UWB Tracking Software Development

    Science.gov (United States)

    Gross, Julia; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dusl, John; Ni, Jianjun; Rafford, Melinda

    2006-01-01

    An Ultra-Wideband (UWB) two-cluster Angle of Arrival (AOA) tracking prototype system is currently being developed and tested at NASA Johnson Space Center for space exploration applications. This talk discusses the software development efforts for this UWB two-cluster AOA tracking system. The role the software plays in this system is to take waveform data from two UWB radio receivers as an input, feed this input into an AOA tracking algorithm, and generate the target position as an output. The architecture of the software (Input/Output Interface and Algorithm Core) will be introduced in this talk. The development of this software has three phases. In Phase I, the software is mostly Matlab driven and calls C++ socket functions to provide the communication links to the radios. This is beneficial in the early stage when it is necessary to frequently test changes in the algorithm. Phase II of the development is to have the software mostly C++ driven and call a Matlab function for the AOA tracking algorithm. This is beneficial in order to send the tracking results to other systems and also to improve the tracking update rate of the system. The third phase is part of future work and is to have the software completely C++ driven with a graphics user interface. This software design enables the fine resolution tracking of the UWB two-cluster AOA tracking system.