Improved Titanium Billet Inspection Sensitivity through Optimized Phased Array Design, Part I: Design Technique, Modeling and Simulation

International Nuclear Information System (INIS)

Lupien, Vincent; Hassan, Waled; Dumas, Philippe

2006-01-01

Reductions in the beam diameter and pulse duration of focused ultrasound for titanium inspections are believed to result in a signal-to-noise ratio improvement for embedded defect detection. It has been inferred from this result that detection limits could be extended to smaller defects through a larger diameter, higher frequency transducer resulting in a reduced beamwidth and pulse duration. Using Continuum Probe Designer TM (Pat. Pending), a transducer array was developed for full coverage inspection of 8 inch titanium billets. The main challenge in realizing a large aperture phased array transducer for billet inspection is ensuring that the number of elements remains within the budget allotted by the driving electronics. The optimization technique implemented by Continuum Probe Designer TM yields an array with twice the aperture but the same number of elements as existing phased arrays for the same application. The unequal area element design was successfully manufactured and validated both numerically and experimentally. Part I of this two-part series presents the design, simulation and modeling steps, while Part II presents the experimental validation and comparative study to multizone

Development on multifunctional phased-array fault inspection technology. Aiming at integrity on internals in nuclear power plant reactors

International Nuclear Information System (INIS)

Komura, Ichiro; Hirasawa, Taiji; Nagai, Satoshi; Naruse, Katsuhiko

2002-01-01

On nuclear power plants sharing an important role in Japanese energy policy, their higher safety and reliability than the other plants are required, and their non-destructive inspection occupies important position for information means to judge their integrity. And, for a part of responses to recent rationalization of the plant operation and increase of aged plants, requirements and positioning onto the non-destructive inspection technology also change. As a result, not only concept on allowable fault sizes is adopted, but also inspection on reactor internals without conventional regulation is obliged to require for size evaluation (sizing) with higher precision to use for secure detection and integrity evaluation of the faults than sizes determined for every internals. For requirement with such higher levels for fault detection and sizing, and for requirement for effective inspection, phased-array supersonic wave fault inspection method is one of the methods with high potential power. Here were introduced on principles and characteristics of the phased-array supersonic wave fault inspection method, and on various fault inspection methods and functions mainly developed for reactor internals inspection. (G.K.)

Application of Piezocomposite Twin, Side by Side, Phased Array UT Probes for the Inspection of Stainless Steel

International Nuclear Information System (INIS)

Delaide, M.; Dumas, Ph

2005-01-01

UT probes to be used for the examination of coarse-grain structure must allow to detect and size cracks, with a high reliability level. The combination of TRL probes, with phased array and piezocomposite technologies allows to improve probes performances and inspection speed. Single element crystals are replaced by matrix arrays, allowing to deflect and skew the beams, to change the inspection depth. This paper describes the designing, the manufacturing and the characterisation of several probes

Improved Titanium Billet Inspection Sensitivity through Optimized Phased Array Design, Part II: Experimental Validation and Comparative Study with Multizone

International Nuclear Information System (INIS)

Hassan, W.; Vensel, F.; Knowles, B.; Lupien, V.

2006-01-01

The inspection of critical rotating components of aircraft engines has made important advances over the last decade. The development of Phased Array (PA) inspection capability for billet and forging materials used in the manufacturing of critical engine rotating components has been a priority for Honeywell Aerospace. The demonstration of improved PA inspection system sensitivity over what is currently used at the inspection houses is a critical step in the development of this technology and its introduction to the supply base as a production inspection. As described in Part I (in these proceedings), a new phased array transducer was designed and manufactured for optimal inspection of eight inch diameter Ti-6Al-4V billets. After confirming that the transducer was manufactured in accordance with the design specifications a validation study was conducted to assess the sensitivity improvement of the PAI over the current capability of Multi-zone (MZ) inspection. The results of this study confirm the significant (≅ 6 dB in FBH number sign sensitivity) improvement of the PAI sensitivity over that of MZI

Automated phased array ultrasonic inspection system for rail wheel sets

International Nuclear Information System (INIS)

Grosser, Paul; Weiland, M.G.

2013-01-01

This paper covers the design, system automation, calibration and validation of an automated ultrasonic system for the inspection of new and in service wheel set assemblies from diesel-electric locomotives and gondola cars. This system uses Phased Array (PA) transducers for flaw detection and Electro-Magnetic Acoustic Transducers (EMAT) for the measurement of residual stress. The system collects, analyses, evaluates and categorizes the wheel sets automatically. This data is archived for future comparison and trending. It is also available for export to a portal lathe for increased efficiency and accuracy of machining, therefore allowing prolonged wheel life.

Phased arrays techniques and split spectrum processing for inspection of thick titanium casting components

International Nuclear Information System (INIS)

Banchet, J.; Chahbaz, A.; Sicard, R.; Zellouf, D.E.

2003-01-01

In aircraft structures, titanium parts and engine members are critical structural components, and their inspection crucial. However, these structures are very difficult to inspect ultrasonically because of their large grain structure that increases noise drastically. In this work, phased array inspection setups were developed to detected small defects such as simulated inclusions and porosity contained in thick titanium casting blocks, which are frequently used in the aerospace industry. A Cut Spectrum Processing (CSP)-based algorithm was then implemented on the acquired data by employing a set of parallel bandpass filters with different center frequencies. This process led in substantial improvement of the signal to noise ratio and thus, of detectability

Advanced 3D tools used in reverse engineering and ray tracing simulation of phased array inspection of turbine components with complex geometry

International Nuclear Information System (INIS)

Daks, W.; Kovacshazy, C.; Mair, D.; Ciorau, P.

2002-01-01

This paper outlines the practical aspects of reverse engineering and the integration of multiple pieces of software (Drafting, CNC Machining, Ray Tracing, Inspection Simulation Scenario and Phased Array UT Analysis), in order to inspect turbine components comprised of complex geometry. The CNC software, Mastercam, and design software, CADKEY/FastSURF, were used to validate the phased-array automated and manual inspection of blade root, rotor steeples and disk-blade rim attachment. The integration of a 3D part in the software engine, Imagine 3D and SimScan, as well as Tomoview analysis (specimen feature) is based on CADKEY Developer Kit - IGES/SAT file format. A generic Ray Tracing simulation for multi-probe beam was integrated into Imagine 3D. Representative examples of reference blocks and mock-ups, UT simulation and phased-array data comparison are presented. (author)

Proving the capabilities of the phased-array probe/ALOK inspection technique

International Nuclear Information System (INIS)

Bohn, H.; Kroening, M.; Rathgeb, W.; Gebhardt, W.; Kappes, W.; Barbian, O.A.

1987-01-01

The capability of the ALOK phased-probe-array inspection technique results from the simplicity of the testing system structure, the reflector detection and identification by means of transit time curves, and the analytical capacity of the system. Testing times are shortened, with the test results meeting the current standards, and further possibilities being given: Areas that could so far only be inspected with difficulty of not at all, can be examined, thanks to the compact equipment and without having to modify the system, very informative analysis measurements for interpreting indications can be made. Furthermore, it may be expected from the testing practice that descriptions of indications will become more reliable and reproducible, due to transit time curve identification. In addition to conventional criteria for reflector evaluation, the potential of transit time curve identification, and flaw boundary imaging of the reconstruction image can be utilized. (orig.)

Manual phased arrays for weld inspections using North American codes

International Nuclear Information System (INIS)

Moles, Michael

2008-01-01

Phased arrays are primarily a method of generating and receiving ultrasound, not a new technology. In addition, the physics of ultrasound generated by phased arrays is identical to that from conventional monocrystals. Not surprisingly, all the major North American (and some European) codes accept phased arrays, either explicitly or implicitly. However, the technique and procedures needs to be proven, typically by a Performance Demonstration. The ASME (AmeicanSociety for Mechanical Engineers) Section V and API RP2X explicitly accept phased arrays. Three ASME code cases have been written specifically fo manual phased array: Code Cases 2541. 2557 and 2558. Over and above the general requirements of Article 4, these Code Cases require full waveform calibration. This is echoed in ASTM E-2491, a Standard Guide for setting up phased arrays. In addition. details such as focusing and reporting are addressed. The American Petroleum Institute QUTE procedure did not need any modifications to be compatible with manual phased arrays. The American Welding Society (AWS) Structural Welding Code D1.1 implicitly accepts phased arrays. New technologies such as phased arrays can be proven using Annex K. Nonetheless, a manual phased array unit using the standard AWS probe and displaying 45, 60 and 70degrees waveforms would be acceptable for D1.1 a s is . Overall, most major North American codes accept phased arrays, however, the technique and procedures must be proven, often using a Performance Demonstration. (author)

Fundamentals of ultrasonic phased arrays

CERN Document Server

Schmerr, Lester W

2014-01-01

This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

Application of immersion phased array UT technique in nickel based alloy weld

International Nuclear Information System (INIS)

Hirasawa, Taiji; Nagai, Satoshi; Murakami, Koji; Yuguchi, Yasuhiro; Ootsubo, Tooru; Naruse, Katsuhiko

2007-01-01

The improvement of defect detection and sizing capabilities for nondestructive inspection technique has been required in order to ensure the reliable operation and life extension of nuclear power plant. Immersion phased array UT technique which is not affected the surface geometry of welds has been developed for inspection of BWR internals such as shroud, shroud support, and so on. Phased array UT technique was applied for shroud support mockup specimen with fatigue crack and partially SCC. From the experimental results, the superior performance of phased array UT for the RPV outside and inside inspection was shown. (author)

A study for soundness of turbine blade root using ultrasonic and phased array

International Nuclear Information System (INIS)

Gil, Doo Song; Park, Sang Ki; Cho, Yong Sang; Lee, Sang Gug; Huh, Kuang Bum

2003-01-01

Power plant is consisted of many component parts for the generation of the electricity and occasionally, turbine equipment may be caused in break-down because of the damage of the blade root. Phased array ultrasonic testing system has become available for power industry. This research describes the characteristics of phased array ultrasonic testing signal for various type of blade roots in thermal power plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phased array ultrasonic testing signal for power plant component in very simple to understand but to difficult for perform the inspection. This paper is focused on the safety of the turbine equipment by the ultrasonic measurement and phased array analysis. As a result of the test through ultrasonic and phased array method, we have concluded that the main damage in these turbine blade roots parts could be generated by the concentrated stress and centrifugal force.

Phased array ultrasound testing on complex geometry

International Nuclear Information System (INIS)

Tuan Arif Tuan Mat; Khazali Mohd Zin

2009-01-01

Phase array ultrasonic inspection is used to investigate its response to complex welded joints geometry. A 5 MHz probe with 64 linear array elements was employed to scan mild steel T-joint, nozzle and node samples. These samples contain many defects such as cracks, lack of penetration and lack of fusion. Ultrasonic respond is analysed and viewed using the Tomoview software. The results show the actual phase array images on respective types of defect. (author)

Surface inspection technique with an eddy current testing array probe

International Nuclear Information System (INIS)

Nishimizu, Akira; Endo, Hisashi; Tooma, Masahiro; Otani, Kenichi; Ouchi, Hirofumi; Yoshida, Isao; Nonaka, Yoshio

2010-01-01

An eddy current testing (ECT) system has been developed for inspecting weld surfaces of components in the reactor pressure vessel of nuclear plants. The system can be applied to curved surfaces with an ECT array probe, it can discriminate flaws from other signal factors by using a combination of arrayed coils signal-phase. The system is applied to a mock-up of core internal components and the signal discrimination using the signal-phase clearly separated flaw and noise signals. (author)

Annular array technology for nondestructive turbine inspection. Final report

International Nuclear Information System (INIS)

Light, G.M.

1986-05-01

The Electric Power Research Institute (EPRI) funded Southwest Research Institute (SwRI) to fabricate and functionally test phased array transducers and an electronic control system with the intent of evaluating the phased array technology for use in the inspection of turbine disks. During this program a 13-element annular array and associated phased array electronics were fabricated and tested and the results of the tests compared to those predicted by theory. The prototype system performed well within the expected limits, and EPRI funded further work to fabricate and test a production unit. The production system consisted of a 25-element annular array and a 25-channel electronics system that had both pulser and receiver delay circuitry. In addition, during the program it was determined that miniaturized hybrid pulser/preamps would be needed to allow the phased array to work over distances exceeding 9.1 meters (30 feet) from the electronics. A circuit developed by SwRI was utilized and found to produce good pulsing capability that did not suffer from impedance mismatch. EPRI also funded (under a separate contract) the fabrication of a small scale static turbine test bed and a full scale dynamic test bed that contained full scale turbine geometries. These test beds were fabricated to enable the production phased array system to be evaluated on turbine disk surfaces. 26 figs

A study for soundness of turbine blade root using ultrasonic and phased array

International Nuclear Information System (INIS)

Gil, Doo Song; Park, Sang Ki; Cho, Yong Sang; Lee, Sang Gug; Huh, Kuang Bum

2003-01-01

Power plant is consisted of many component parts for the generation of the electricity, and occasionally, turbine equipment may be caused in break-down because of the damage of the blade root. Phased array ultrasonic testing system has become available for practical application in complicated geometry such as turbine blade root, tenon, disc in power industry. This research describes the characteristics of phased array ultrasonic testing signal for various type of blade roots in thermal Power Plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phased array ultrasonic testing signal for power plant component in very simple to understand but to difficult for perform the inspection. This paper is focused on the safety of the turbine equipment by the ultrasonic measurement and phased array analysis. As a result of the test through ultrasonic and phased array method, we have concluded that the main damage in these turbine blade root parts could be generated by the concentrated stress and centrifugal force.

Improvement of ultrasonic testing by use of phased arrays

International Nuclear Information System (INIS)

Gebhardt, W; Bonitz, F.; Woll, H.

1983-01-01

The paper examines the applicability of phased-array technology in non-destructive material testing for quality control, basic inspection and in-service inspections of the primary containment of nuclear power plants. Initial experiments on sonic aigrette control, defect margin reconstruction and the classification of defects have been carried out using medical equipment as commercially available which had been modified for non-destructive applications. At the same time, a for more flexible microcomputer-controlled phased-array system was developed, particularly designed for material testing. (orig./RW) [de

Development of portable phased array UT system for real-time flaw imaging

International Nuclear Information System (INIS)

Goto, M.

1995-01-01

Many functions and features of phased array UT technology must be useful for NDE in the industrial field. Some phased array UT systems have been developed for the inspection of nuclear pressure vessel and turbine components. However, phased array UT is still a special NDE technique and it has not been used widely in the past. The reasons of that are system size, cost, operator performance, equipment design and others. TOSHIBA has newly developed PC controlled portable phased array system to solve those problems. The portable phased array UT system is very compact and light but it is able to drive up to 32-channel linear array probe, to display real-time linear/sector B-scan, to display accumulated B-scan with an encoder and to display profile overlaid B-scan. The first applications were turbine component inspections for precise flaw investigation and flaw image data recording

Characteristic Assessments of the Phased Array UT System Developed by KHNP

Energy Technology Data Exchange (ETDEWEB)

Cho, Chan-Hee; Jee, Dong-Hyun; Lee, Tae-Hun; Yoo, Hyun-Ju [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

The ultrasonic testing (UT) is an important one of the nondestructive examination methods which are used for the in-service inspection in the nuclear power plant. It is mainly used for the inspection of welds in piping and nozzle for many components. Technologies for the ultrasonic testing have been advanced for the reduction of inspection time and the increase of inspection reliability. In the manual ultrasonic testing system, it is not easy to compare the variation of inspection signals over time, because the data cannot be stored during the inspection. For the purpose of inspecting nuclear power components, the KHNP developed a phased array UT system including pulser-receiver, AD converter, beam-former, phased array probe, and scanner with 3-directional degree of freedom. Characteristics of the KHNP PA system and the results of acquired signals are described in detail in this paper.

Characteristic Assessments of the Phased Array UT System Developed by KHNP

International Nuclear Information System (INIS)

Cho, Chan-Hee; Jee, Dong-Hyun; Lee, Tae-Hun; Yoo, Hyun-Ju

2016-01-01

The ultrasonic testing (UT) is an important one of the nondestructive examination methods which are used for the in-service inspection in the nuclear power plant. It is mainly used for the inspection of welds in piping and nozzle for many components. Technologies for the ultrasonic testing have been advanced for the reduction of inspection time and the increase of inspection reliability. In the manual ultrasonic testing system, it is not easy to compare the variation of inspection signals over time, because the data cannot be stored during the inspection. For the purpose of inspecting nuclear power components, the KHNP developed a phased array UT system including pulser-receiver, AD converter, beam-former, phased array probe, and scanner with 3-directional degree of freedom. Characteristics of the KHNP PA system and the results of acquired signals are described in detail in this paper

Development of a robotic nozzle inspection with a flexible transducer array

International Nuclear Information System (INIS)

Dobigny, Blandine; Wattiau, Olivier; Bey, Sebastien; Vanhoye, Arnaud; Ancrenaz, Patrick; Dumas, Philippe; Fournier, Laurent

2016-01-01

The evaluation of the integrity of the nuclear plant components is a major issue. It is mandatory to assess the degradation due to the aging. NDE aim is to detect potential defects, resulting of thermal fatigue, and to be able to evaluate their dimensions. Ultrasonic non destructive testing has demonstrated its efficiency for detection and characterization of such defects and industrial probes offer satisfactory results in various applications. However, the complex geometry of some components (nozzle,..) severely limits the inspection performances. Indeed, the use of conventional probes is restricted to regular surfaces. Flexible transducer arrays technology provides an attractive solution in ultrasonic NDT for the inspection of complex geometry components. Its ability to conform to the wavy surface of the component and to ensure a good coupling when the limits of conventional probes are reached, makes it suitable for the characterization of a defect detected in a nozzle. To develop and implement a flexible probe inspection of a nozzle weld, several skills are needed: especially ultrasonic, robotic, simulation skills. Moreover, an innovative tool dedicated to delay laws and probe position calculation is used to optimize the performance of such phased array probes. In the framework of a partnership, EDF, the CEA LIST and AREVA have developed a robotic inspection tool able to be operate on nuclear site, in order to characterize defects located in the inner radius of a nozzle with a flexible transducer array. The article describes the use of the new tools developed for the nozzle case. It also presents acquisition results and the contribution of this technology of potential defect characterization. These results are compared to classical phased-array methods.

Innovative Ultrasonic Testing (UT) of nuclear components by sampling phased array with 3D visualization of inspection results

OpenAIRE

Pudovikov, Sergey; Bulavinov, Andrey; Pinchuk, Roman

2011-01-01

Unlike other industrial branches, nuclear industry - when performing UT- is not only asking for a reliable detection, but also for an exact sizing of material defects. Under these objectives ultrasonic imaging plays an important role in practical testing of nuclear components in the data evaluation process as well as for documentation of the inspection results. 2D and 3D sound-field steering by means of phased array technology offers great opportunities for spatially correct visualization of ...

A new concept of smart flexible phased array transducer to inspect component of complex geometry

International Nuclear Information System (INIS)

Roy, O.; Mauhaut, S.; Casula, O.; Cattiaux, G.

2001-01-01

In most of industries as aeronautics, aerospace and nuclear, the main part of the non destructive testing is carried out directly in touch with the inspected component. Among others, the cooling piping of French pressurized water reactor comprises many welding components with complex geometry: elbows, butt welds, nozzles. In service inspections of such components performed with conventional ultrasonic contact transducers present limited performances. First, variations in sensitivity, due to unmatched contact on depressions or irregular surface are observed, resulting in poor detection performances. In addition, the beam orientation transmitted through complex interfaces cannot be totally controlled, because of the disorientations suffered by the transducer during its displacement. As a result, the possible defect cannot be correctly detected, positioned and characterized. To overcome these difficulties and to improve the performances of such inspections, the French Atomic Energy Commission has developed a new concept of transducer, allowing both to take into account the varying profile of the tested component and to efficiently compensate these effects. This transducer is a flexible phased array able to match the surface of the inspected specimen and to efficiently compensate the deformation of its own surface, in order to preserve the ultrasonic beam characteristics in spite of the profile variations encountered during the scanning. This ability is achieved thanks to a specific instrumentation, which measures the deformation of the transducer radiating surface, made of individual ultrasonic elements mechanically jointed to fit the actual surface of the component being inspected. Inspections in pulse-echo mode have been performed on a specimen with an irregular profile containing artificial embedded reflectors. The comparison with inspection carried out using conventional transducer shows the efficiency of the system to characterize defects under such complex

A contribution to phased array ultrasonic inspection of welds: defect patterns and sizing capability

Energy Technology Data Exchange (ETDEWEB)

Ciorau, P., E-mail: peter.ciorau@opg.com [Ontario Power Generation Inc., Inspection, Maintenance and Commercial Services, Tiverton, Ontario (Canada)

2008-07-01

The paper presents defect patterns for weld inspection detected with phased array ultrasonic technology (PAUT). The sizing capability for length, height, outer and inner ligament for specific implanted weld defects in training samples and mock-ups with thickness between 6.4-52 mm. It is discussed the influence of beam angle on sizing the lack of fusion defect. More than 50 implanted weld defects with 70% crack population were sized using high-frequency (5-10 MHz) linear array probes. The correlation between the design/manufacturer flaw size and PAUT data for length, height and ligament is graphically presented. It was concluded the length is oversized by 2-6 mm, height and inner ligament are undersized by 0.2 to 0.5 mm, and outer ligament is oversized by 0.5 mm. The sizing results were based on non-amplitude techniques and pattern display of S- and B-scan. The sizing capability is far better than ASME XI tolerances for performance demonstration and comparable to time of flight diffraction (TOFD) ideal tolerances. (author)

A contribution to phased array ultrasonic inspection of welds: defect patterns and sizing capability

International Nuclear Information System (INIS)

Ciorau, P.

2008-01-01

The paper presents defect patterns for weld inspection detected with phased array ultrasonic technology (PAUT). The sizing capability for length, height, outer and inner ligament for specific implanted weld defects in training samples and mock-ups with thickness between 6.4-52 mm. It is discussed the influence of beam angle on sizing the lack of fusion defect. More than 50 implanted weld defects with 70% crack population were sized using high-frequency (5-10 MHz) linear array probes. The correlation between the design/manufacturer flaw size and PAUT data for length, height and ligament is graphically presented. It was concluded the length is oversized by 2-6 mm, height and inner ligament are undersized by 0.2 to 0.5 mm, and outer ligament is oversized by 0.5 mm. The sizing results were based on non-amplitude techniques and pattern display of S- and B-scan. The sizing capability is far better than ASME XI tolerances for performance demonstration and comparable to time of flight diffraction (TOFD) ideal tolerances. (author)

Development of high-performance phased-array UT system 'DYNARAY' and its application examples

International Nuclear Information System (INIS)

Ehara, Eiji

2011-01-01

This article outlined the history leading to develop high-performance phased-array (PA) UT system called DYNARAY, with up to 256 phased-array active channels and maximum 4096 focal laws, lowering the inspection time. As examples it was applied to in-service inspection of reactor pressure vessel welded joints using module of PA-UT probe or eddy-current probe, inspection of seal welds of dry storage containers using scanner of PA-UT, crack detection of end ring of generators using PA-UT probe and UT inspection of cast austenitic stainless steel using 500 kHz probe. Advanced data acquisition and analysis functions for PA-UT system had been developed. (T. Tanaka)

A novel serrated columnar phased array ultrasonic transducer

Science.gov (United States)

Zou, Cheng; Sun, Zhenguo; Cai, Dong; Song, Hongwei; Chen, Qiang

2016-02-01

Traditionally, wedges are required to generate transverse waves in a solid specimen and mechanical rotation device is needed for interrogation of a specimen with a hollow bore, such as high speed railway locomotive axles, turbine rotors, etc. In order to eliminate the mechanical rotation process, a novel array pattern of phased array ultrasonic transducers named as serrated columnar phased array ultrasonic transducer (SCPAUT) is designed. The elementary transducers are planar rectangular, located on the outside surface of a cylinder. This layout is aimed to generate electrically rotating transverse waveforms so as to inspect the longitudinal cracks on the outside surface of a specimen which has a hollow bore at the center, such as the high speed railway locomotive axles. The general geometry of the SCPAUT and the inspection system are illustrated. A FEM model and mockup experiment has been carried out. The experiment results are in good agreement with the FEM simulation results.

Improvements in the UT Inspection of vessel nozzles. Array application

International Nuclear Information System (INIS)

Tanarro, A.; Garcia, A.; Izquierdo, J.

1998-01-01

Automatic ultrasonic inspection of certain components in nuclear power plants, together with problems related to access of same, result in other difficulties due to the complexity of their geometry and the apparent orientation of possible defects. Array technology, recently developed on the basis of the theoretical principals of phased array technique, has meant that it is now possible to advance in the characterisation, localisation, and sizing of the defects in these components. This has been possible thanks to the discovery of synthetic materials which have allowed us to design and manufacture a new group of ultrasonic transducers. To these we may add new developments in electronics and computer sciences which have facilitated the building of high-powered control systems. This report discusses the work carried out by Tecnatom and Iberdrola in the field of automatic ultrasonic inspection of the vessel nozzles by means of array technology in the BWR at the Cofrentes Nuclear Power Station. The aims of this work were: - To facilitate the detection, characterisation, sizing and positioning of defects - To simplify and improve ultrasonic inspection in order to reduce acquisition times and the cost of same In order to achieve these results the following items were developed: - New array transducers were designed and manufactured - A new data acquisition system was developed - New programs for analysing data and for simulating ultrasonic testing was developed - The results have been validated in mock up. (Author)

Ultrasonic phased array examination of circumferential weld joint in reactor pressure vessel of BWR

Energy Technology Data Exchange (ETDEWEB)

Nanekar, Paritosh, E-mail: pnanekar@barc.gov.in [Quality Assurance Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Jothilakshmi, N. [Quality Assurance Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Jayakumar, T. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

2013-12-15

Highlights: • Phased array technique developed for weld joint inspection in BWR pressure vessel. • Simulation studies were carried out for conventional and phased array probe. • Conventional ultrasonic test shows in-adequate weld coverage and poor resolution. • Focused sound beam in phased array results in good resolution and sensitivity. • Ultrasonic phased array technique is validated on mock-up with reference defects. - Abstract: The weld joints in the reactor pressure vessel (RPV) of Boiling Water Reactors (BWR) are required to be examined periodically for assurance of structural integrity. Ultrasonic phased array examination technique has been developed in authors’ laboratory for inspection of the top flange to shell circumferential weld joint in RPV of BWRs, which are in operation in India since the late 1960s. The development involved detailed simulation studies for computation of focal laws followed by validation on mock-up. The paper brings out the limitations of the conventional ultrasonic technique and how this can be overcome by the phased array approach for the weld joint under consideration. The phased array technique was successfully employed for field examination of this weld joint in RPV during the re-fuelling outage.

Simulation Based Investigation of Focusing Phased Array Ultrasound in Dissimilar Metal Welds

Directory of Open Access Journals (Sweden)

Hun-Hee Kim

2016-02-01

Full Text Available Flaws at dissimilar metal welds (DMWs, such as reactor coolant systems components, Control Rod Drive Mechanism (CRDM, Bottom Mounted Instrumentation (BMI etc., in nuclear power plants have been found. Notably, primary water stress corrosion cracking (PWSCC in the DMWs could cause significant reliability problems at nuclear power plants. Therefore, phased array ultrasound is widely used for inspecting surface break cracks and stress corrosion cracks in DMWs. However, inspection of DMWs using phased array ultrasound has a relatively low probability of detection of cracks, because the crystalline structure of welds causes distortion and splitting of the ultrasonic beams which propagates anisotropic medium. Therefore, advanced evaluation techniques of phased array ultrasound are needed for improvement in the probability of detection of flaws in DMWs. Thus, in this study, an investigation of focusing and steering phased array ultrasound in DMWs was carried out using a time reversal technique, and an adaptive focusing technique based on finite element method (FEM simulation. Also, evaluation of focusing performance of three different focusing techniques was performed by comparing amplitude of phased array ultrasonic signals scattered from the targeted flaw with three different time delays.

New customizable phased array UT instrument opens door for furthering research and better industrial implementation

International Nuclear Information System (INIS)

Dao, Gavin; Ginzel, Robert

2014-01-01

Phased array UT as an inspection technique in itself continues to gain wide acceptance. However, there is much room for improvement in terms of implementation of Phased Array (PA) technology for every unique NDT application across several industries (e.g. oil and petroleum, nuclear and power generation, steel manufacturing, etc.). Having full control of the phased array instrument and customizing a software solution is necessary for more seamless and efficient inspections, from setting the PA parameters, collecting data and reporting, to the final analysis. NDT researchers and academics also need a flexible and open platform to be able to control various aspects of the phased array process. A high performance instrument with advanced PA features, faster data rates, a smaller form factor, and capability to adapt to specific applications, will be discussed

Evidence of performance for phased array/ALOK-inspection technique

International Nuclear Information System (INIS)

Bohn, H.; Kroening, M.; Rathgeb, W.; Gebhardt, W.; Kappes, W.; Barbian, O.A.

1986-01-01

Phased-array probes combined with the ALOK method give an US test system which results in major improvements of automated ultrasonic testing of pressure vessels. The authors discuss the improvements in test execution, defect detection and interpretation by means of tandem defects and defect detection in fault displays. (DG) [de

Non-destructive evaluation of welding part of stainless steels by phased array system

International Nuclear Information System (INIS)

Tatematsu, Nobuhiro; Matsumoto, Eiji

2009-01-01

Recently, more accurate and convenient Non-Destructive Evaluation techniques are required for flaw inspection of structural materials. Phased array ultrasonic transducers are expected as such as NDE technique but there are many subjects to be solved. Furthermore, commercial phased array systems with conventional scanning and imaging techniques have not fulfilled their maximum potential. The purpose of this paper is to improve the phased array system to be applicable to the inhomogeneity evaluation of welding part of stainless steels. (author)

Design Concept of Array ECT Sensor for Steam Generator Tubing Inspection

Energy Technology Data Exchange (ETDEWEB)

Cho, Chan Hee; Lee, Tae Hun; Yoo, Hyun Ju [Korea Hydro and Nuclear Power Co. Ltd. CRI, Daejeon (Korea, Republic of)

2015-05-15

The eddy current testing, which is one of the nondestructive examination methods, is widely used for the inspection of heat exchangers including steam generator tubing in the nuclear power plant. It uses electromagnetic induction to detect flaws in conductive materials. Two types of eddy current probes are conventionally used for the inspection of steam generator tubing according to the main purpose. One is the bobbin probe technology and the other is the rotating probe. During the inspection, they have restrictions for the flaw detection or the inspection speed. An array probe can be alternative to the bobbin and rotating probes. The design concept of array coils with high sensitivity is described in this paper. It is expected that the eddy current testing using this type of array sensors may provide high detectability and resolution for flaws in steam generator tubing. Eddy current technology has some barriers for the inspection of steam generator tubing in the nuclear power plant. Bobbin probes offer poor circumferential crack detection and rotating probes are time and money consuming due to the mechanical rotation. Array probe inspection technique can replace bobbin and rotating probe techniques due to its sensitivity for flaw detection and inspection speed. In general, circular-shaped coils are considered in an array eddy current probe.

Sensor Fusion Techniques for Phased-Array Eddy Current and Phased-Array Ultrasound Data

Energy Technology Data Exchange (ETDEWEB)

Arrowood, Lloyd F. [Y-12 National Security Complex, Oak Ridge, TN (United States)

2018-03-15

Sensor (or Data) fusion is the process of integrating multiple data sources to produce more consistent, accurate and comprehensive information than is provided by a single data source. Sensor fusion may also be used to combine multiple signals from a single modality to improve the performance of a particular inspection technique. Industrial nondestructive testing may utilize multiple sensors to acquire inspection data depending upon the object under inspection and the anticipated types of defects that can be identified. Sensor fusion can be performed at various levels of signal abstraction with each having its strengths and weaknesses. A multimodal data fusion strategy first proposed by Heideklang and Shokouhi that combines spatially scattered detection locations to improve detection performance of surface-breaking and near-surface cracks in ferromagnetic metals is shown using a surface inspection example and is then extended for volumetric inspections. Utilizing data acquired from an Olympus Omniscan MX2 from both phased array eddy current and ultrasound probes on test phantoms, single and multilevel fusion techniques are employed to integrate signals from the two modalities. Preliminary results demonstrate how confidence in defect identification and interpretation benefit from sensor fusion techniques. Lastly, techniques for integrating data into radiographic and volumetric imagery from computed tomography are described and results are presented.

Application of Phased Array Ultrasonic Testing (PAUT) on Single V-Butt Weld Integrity Determination

International Nuclear Information System (INIS)

Amry Amin Abas; Mohd Kamal Shah Shamsudin; Norhazleena Azaman

2015-01-01

Phased Array Ultrasonic Testing (PAUT) utilizes arrays of piezoelectric elements that are embedded in an epoxy base. The benefit of having such kind of array is that beam forming such as steering and focusing the beam front possible. This enables scanning patterns such as linear scan, sectorial scan and depth focusing scan to be performed. Ultrasonic phased array systems can potentially be employed in almost any test where conventional ultrasonic flaw detectors have traditionally been used. Weld inspection and crack detection are the most important applications, and these tests are done across a wide range of industries including aerospace, power generation, petrochemical, metal billet and tubular goods suppliers, pipeline construction and maintenance, structural metals, and general manufacturing. Phased arrays can also be effectively used to profile remaining wall thickness in corrosion survey applications. The benefits of PAUT are simplifying inspection of components of complex geometry, inspection of components with limited access, testing of welds with multiple angles from a single probe and increasing the probability of detection while improving signal-to-noise ratio. This paper compares the result of inspection on several specimens using PAUT as to digital radiography. The specimens are welded plates with single V-butt weld made of carbon steel. Digital radiography is done using blue imaging plate with x-ray source. PAUT is done using Olympus MX2 with 5 MHz probe consisting of 64 elements. The location, size and length of defect is compared. (author)

Liquid sodium testing of in-house phased array EMAT transducer for L-wave applications

Energy Technology Data Exchange (ETDEWEB)

Le Bourdais, F.; Le Polles, T. [Non Destructive Testing Department at the French Atomic Energy Commission (CEA), Saclay, 91191 Gif sur Yvette CEDEX, (France); Baque, F. [Department of Sodium Technology at the French Atomic Energy Commission (CEA), Cadarache, 13108 St Paul lez Durance CEDEX, (France)

2015-07-01

This paper describes the development of an in-house phased array EMAT transducer for longitudinal wave inspection in liquid sodium. The work presented herein is part of an undergoing project aimed at improving in-service inspection techniques for the ASTRID reactor project. The design process of the phased array EMAT probe is briefly explained and followed by a review of experimental test results. We first present test results obtained in the laboratory while the last part of the paper describes the liquid sodium testing and the produced ultrasound images. (authors)

Liquid sodium testing of in-house phased array EMAT transducer for L-wave applications

International Nuclear Information System (INIS)

Le Bourdais, F.; Le Polles, T.; Baque, F.

2015-01-01

This paper describes the development of an in-house phased array EMAT transducer for longitudinal wave inspection in liquid sodium. The work presented herein is part of an undergoing project aimed at improving in-service inspection techniques for the ASTRID reactor project. The design process of the phased array EMAT probe is briefly explained and followed by a review of experimental test results. We first present test results obtained in the laboratory while the last part of the paper describes the liquid sodium testing and the produced ultrasound images. (authors)

Phased array concept for the ultrasonic inservice inspection of the spherical bottom of BWR-pressure vessels

International Nuclear Information System (INIS)

Brekow, G.; Wuestenberg, H.; Moehrle, W.; Schulz, E.

1989-01-01

The spherical bottom of BWR-pressure vessels contains holes for the nozzles of control rods and instrumentation. Up to now the detectable areas for the ultrasonic inspection are the accessible ligaments between the nozzles with an orientation parallel and transverse to the manipulator rails. Some licensing authorities demand an inspection technique capable of reliably detecting significant crack initiation in all critical areas near the cladding of the spherical inner surface. By order and in cooperation with the HEW we have developed a computer controlled equipment with two ultrasonic probes containing four linear arrays and a digitized A-scan storage for documentation and evaluation of inspection results. The manipulator guided probe movement in the paths between the nozzles of the spherical bottom is controlled by a computer program. This program determines for each array system and for each coupling position the beam angle as a function of the variable skewing angle to realize detection conditions suited to possible crack positions at the longitudinal, transverse and diagonal ligaments between the nozzles for control rods and instrumentation. (orig./HP)

Looking Below the Surface with Ultrasonic Phased Array

International Nuclear Information System (INIS)

Cinson, Anthony D.; Crawford, Susan L.

2010-01-01

This article is a brief tutorial on the benefits of volumetric ultrasonic phased array line scanning. The article describes the need, the approach, and the methods/practices used to analyze the data for flaw detection and characterization in the nuclear power plant component arena. If you are inspecting the integrity of nuclear power plant components during a scheduled outage, time is likely against you. Time is a luxury that most inspectors do not possess in their daily jobs. They are required to quickly and efficiently perform nondestructive testing (NDT) on various components within the nuclear power plant facility. In addition to the obvious financial impacts ($1M+ per day) of prolonging planned outages, time constraints also are put in place for the safety and health of the inspectors. For instance, while working in highly radioactive or contaminated environments of the plant, inspectors have a limited window of time to volumetrically inspect components for flaws, such as cracks, defects or other anomalies that might lead to leakage or failure during operation. In the interest of simplicity, flaws are limited to cracks for our purposes. Ultrasonic phased array volumetric line scanning is emerging as a powerful tool that allows for quick inspections of components that had been very time-consuming using earlier technologies.

Determination of Focal Laws for Ultrasonic Phased Array Testing of Dissimilar Metal Welds

International Nuclear Information System (INIS)

Jing, Ye; Kim, Hak Joon; Song, Sung Jin; Song, Myung Ho; Kang, Suk Chull; Kang, Sung Sik; Kim, Kyung Cho

2008-01-01

Inspection of dissimilar metal welds using phased array ultrasound is not easy at all, because crystalline structure of dissimilar metal welds cause deviation and splitting of the ultrasonic beams. Thus, in order to have focusing and/or steering phased array beams in dissimilar metal welds, proper time delays should be determined by ray tracing. In this paper, we proposed an effective approach to solve this difficult problem. Specifically, we modify the Oglivy's model parameters to describe the crystalline structure of real dissimilar metal welds in a fabricated specimen. And then, we calculate the proper time delay and incident angle of linear phased array transducer in the anisotropic and inhomogeneous material for focusing and/or steering phased array ultrasonic beams on the desired position

Low Frequency Phased Array Application for Crack Detection in Cast Austenitic Piping

International Nuclear Information System (INIS)

Anderson, Michael T.; Cumblidge, Stephen E.; Doctor, Steven R.

2006-01-01

As part of a multi-year program funded by the United States Nuclear Regulatory Commission (US NRC) to address nondestructive examination (NDE) reliability of inservice inspection (ISI) programs, studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, have focused on assessing novel NDE approaches for the inspection of coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the US NRC on the utility, effectiveness and reliability of ultrasonic testing (UT) as related to the ISI of primary piping components in US commercial nuclear power plants. This paper describes progress, recent developments and results from an assessment of a portion of the work relating to the ultrasonic low frequency phased array inspection technique. Westinghouse Owner's Group (WOG) cast stainless steel pipe segments with thermal and mechanical fatigue cracks, PNNL samples containing thermal fatigue cracks and several blank vintage specimens having very coarse grains that are representative of early centrifugally cast piping installed in PWRs, were used for assessing the inspection method. The phased array approach was implemented using an R/D Tech Tomoscan III system operating at 1.0 MHz and 500 kHz, providing composite volumetric images of the samples. Several dual, transmit-receive, custom designed low-frequency arrays were employed in laboratory trials. Results from laboratory studies for assessing detection, localization and length sizing effectiveness are discussed.

Scanning moiré and spatial-offset phase-stepping for surface inspection of structures

Science.gov (United States)

Yoneyama, S.; Morimoto, Y.; Fujigaki, M.; Ikeda, Y.

2005-06-01

In order to develop a high-speed and accurate surface inspection system of structures such as tunnels, a new surface profile measurement method using linear array sensors is studied. The sinusoidal grating is projected on a structure surface. Then, the deformed grating is scanned by linear array sensors that move together with the grating projector. The phase of the grating is analyzed by a spatial offset phase-stepping method to perform accurate measurement. The surface profile measurements of the wall with bricks and the concrete surface of a structure are demonstrated using the proposed method. The change of geometry or fabric of structures and the defects on structure surfaces can be detected by the proposed method. It is expected that the surface profile inspection system of tunnels measuring from a running train can be constructed based on the proposed method.

Procedure Development and Qualification of the Phased Array Ultrasonic Testing for the Nuclear Power Plant Piping Weld

International Nuclear Information System (INIS)

Yoon, Byung Sik; Yang, Seung Han; Kim, Yong Sik; Lee, Hee Jong

2010-01-01

The manual ultrasonic examination for the nuclear power plant piping welds has been demonstrated by using KPD(Korean Performance Demonstration) generic procedure. For automated ultrasonic examination, there is no generic procedure and it should be qualified by using applicable automated equipment. Until now, most of qualified procedures used pulse-echo technique and there is no qualified procedure using phased array technique. In this study, data acquisition and analysis software were developed and phased-array transducer and wedge were designed to implement phased array technique for nuclear power plant in-service inspection. The developed procedure are qualified for performance demonstration for the flaw detection, length sizing and depth sizing. The qualified procedure will be applied for the field examination in the nuclear power plant piping weld inspection

Using Low-Frequency Phased Arrays to Detect Cracks in Cast Austenitic Piping Components

International Nuclear Information System (INIS)

Anderson, Michael T.; Cumblidge, Stephen E.; Doctor, Steven R.

2005-01-01

As part of a multi-year program funded by the United States Nuclear Regulatory Commission (US NRC) to address NDE reliability of inservice inspection (ISI) programs, recent studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, have focused on assessing novel NDE approaches for the inspection of coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the US NRC on the utility, effectiveness and reliability of ultrasonic testing (UT) and eddy current testing (ET) inspection techniques as related to the ISI of primary piping components in pressurized water reactors (PWRs). This paper describes progress, recent developments and early results from an assessment of a portion of this work relating to the ultrasonic low frequency phased array inspection technique. Westinghouse Owner's Group (WOG) cast stainless steel pipe segments with thermal and mechanical fatigue cracks, PNNL samples containing thermal fatigue cracks and several blank vintage specimens having very coarse grains that are representative of early centrifugally cast piping installed in PWRs, are being used for assessing the inspection method. The phased array approach was implemented using an R/D Tech Tomoscan III system operating at 1.0 MHz and 500 kHz, providing composite volumetric images of the samples. Several dual, transmit-receive, custom designed low-frequency arrays are employed in laboratory trials. Results from laboratory studies for assessing detection of thermal and mechanical fatigue cracks in cast stainless steel piping welds are discussed

Development and implementation of UT procedures for nuclear and other applications using TRL phased array probes

International Nuclear Information System (INIS)

Chardome, V.; Delaide, M.; Cermak, J.; Cruysweegs, E.; Plateau, M.

2006-01-01

In the past, Vincotte developed, qualified and applied various UT procedures for the automated in-service inspection of austenitic and dissimilar metal welds, using conventional ultrasonic probes. In a process of continuous improvement, Vincotte is upgrading these existing procedures by applying low frequency TRL phased array probes. This presentation situates this recent innovation within the phased array history of Vincotte. Particular attention will be paid to these newest phased array developments, in terms of probe development, angled beam generation and scanning patterns. (orig.)

Stereo imaging and random array stratified imaging for cargo radiation inspecting

International Nuclear Information System (INIS)

Wang Jingjin; Zeng Yu

2003-01-01

This paper presents a Stereo Imaging and Random Array Stratified Imaging for cargo container radiation Inspecting. By using dual-line vertical detector array scan, a stereo image of inspected cargo can be obtained and watched with virtual reality view. The random detector array has only one-row of detectors but distributed in a certain horizontal dimension randomly. To scan a cargo container with this random array detector, a 'defocused' image is obtained. By using 'anti-random focusing', one layer of the image can be focused on the background of all defocused images from other layers. A stratified X-ray image of overlapped bike wheels is presented

Phased-array radars

Science.gov (United States)

Brookner, E.

1985-02-01

The operating principles, technology, and applications of phased-array radars are reviewed and illustrated with diagrams and photographs. Consideration is given to the antenna elements, circuitry for time delays, phase shifters, pulse coding and compression, and hybrid radars combining phased arrays with lenses to alter the beam characteristics. The capabilities and typical hardware of phased arrays are shown using the US military systems COBRA DANE and PAVE PAWS as examples.

Evaluation of ultrasonic array imaging algorithms for inspection of a coarse grained material

Science.gov (United States)

Van Pamel, A.; Lowe, M. J. S.; Brett, C. R.

2014-02-01

Improving the ultrasound inspection capability for coarse grain metals remains of longstanding interest to industry and the NDE research community and is expected to become increasingly important for next generation power plants. A test sample of coarse grained Inconel 625 which is representative of future power plant components has been manufactured to test the detectability of different inspection techniques. Conventional ultrasonic A, B, and C-scans showed the sample to be extraordinarily difficult to inspect due to its scattering behaviour. However, in recent years, array probes and Full Matrix Capture (FMC) imaging algorithms, which extract the maximum amount of information possible, have unlocked exciting possibilities for improvements. This article proposes a robust methodology to evaluate the detection performance of imaging algorithms, applying this to three FMC imaging algorithms; Total Focusing Method (TFM), Phase Coherent Imaging (PCI), and Decomposition of the Time Reversal Operator with Multiple Scattering (DORT MSF). The methodology considers the statistics of detection, presenting the detection performance as Probability of Detection (POD) and probability of False Alarm (PFA). The data is captured in pulse-echo mode using 64 element array probes at centre frequencies of 1MHz and 5MHz. All three algorithms are shown to perform very similarly when comparing their flaw detection capabilities on this particular case.

Acoustic field of focusing phased array probe and the scanning system

International Nuclear Information System (INIS)

Murai, J.; Miura, S.; Ida, T.; Shiraiwa, T.; Miya, T.

1997-01-01

Acoustic field of a point focusing cylindrical linear array probe, in which focusing in the axial direction of cylinder is done by the phased linear array and focusing in the orthogonal direction is done geometrically, was studied by numerical calculation and an optimum design of phased array probe for focusing has been obtained. In generally speaking, the beam width at focus point decreases with decrease of width of each transducer element and with increase of synthetic aperture made by total elements. If the number of total array elements excited as one pulse is limited, the above conditions are contradicted. Thus, an optimum element width exists for the best focusing. On the above consideration, we can get focusing ability of phased array nearly as same as geometrical focusing. A developed transducer is a linear array of polymer piezoelectric material of cylindrical shape, of which radius is from 50 mm to 75 mm. The frequency is 10 Mhz and the beam width of 0.5 mm (depending on aperture) in the orthogonal direction to the cylinder axis and 0.7 mm width in the cylinder axis (phased array focusing) have been obtained. A delay circuit for exciting the transducer was newly designed to give maximum performance to the array regarding to accuracy, stability, easy control and etc. A c-scan ultrasonic testing system equipped with this transducer has sixteen times inspection speed compared to the single probe instrument.

Phased array ultrasonic testing of dissimilar metal pipe weld joints

International Nuclear Information System (INIS)

Rajeev, J.; Sankaranarayanan, R.; Sharma, Govind K; Joseph, A.; Purnachandra Rao, B.

2015-01-01

Dissimilar metal weld (DMW) joints made of stainless steel and ferritic steel is used in nuclear industries as well as oil and gas industries. These joints are prone to frequent failures which makes the non-destructive testing of dissimilar metal weld joints utmost important for reliable and safe operation of nuclear power plants and oil and gas industries. Ultrasonic inspection of dissimilar metal weld joints is still challenging due to the inherent anisotropic and highly scattering nature. Phased array ultrasonic testing (PAUT) is an advanced technique and its capability has not been fully explored for the inspection of dissimilar metal welds

Dynamic focusing of phased arrays for nondestructive testing: characterization and application

International Nuclear Information System (INIS)

Lamarre, A.; Mainguy, F.

1999-01-01

Recent developments in Phased Array hardware developed by R/D TECH for nondestructive testing now allow dynamic focusing on reception. This new option, borrowed from medical technology, enables a programmable, real-time array response on reception by modifying the delay line, the gain, and the activation of each element as a function of time. This technology is presented as a new powerful tool, which can extend the depth-of-field, reduce the beam spread and increase the overall signal-to-noise ratio. Implementation of dynamic focusing in Phased Array systems will present many advantages such as an increase of the Pulse Rate Frequency (PRF). The technology implies a lot of significant possibilities, but also an extensive beam characterization. Some results are presented to quantify the advantages and drawbacks of the technique in comparison with standard phased array zone focusing and conventional UT. Results are clearly demonstrating the effect of dynamic focusing on the depth-of-field, the beam spread, the signal-to-noise ratio, and the acquisition rate, both with linear and annular arrays. Therefore this technique is suitable for applications where long soundpaths and small beam divergence are required as boresonic, billet, and blade root inspections. (author)

Linear Array Ultrasonic Transducers: Sensitivity and Resolution Study

International Nuclear Information System (INIS)

Kramb, V.A.

2005-01-01

The University of Dayton Research Institute (UDRI) under contract by the US Air Force has designed and integrated a fully automated inspection system for the inspection of turbine engines that incorporates linear phased array ultrasonic transducers. Phased array transducers have been successfully implemented into weld and turbine blade root inspections where the defect types are well known and characterized. Embedded defects in aerospace turbine engine components are less well defined, however. In order to determine the applicability of linear arrays to aerospace inspections the sensitivity of array transducers to embedded defects in engine materials must be characterized. In addition, the implementation of array transducers into legacy inspection procedures must take into account any differences in sensitivity between the array transducer and that of the single element transducer currently used. This paper discusses preliminary results in a study that compares the sensitivity of linear array and conventional single element transducers to synthetic hard alpha defects in a titanium alloy

Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Phased arrays, ultrasonic imaging and nonlinear acoustics

Energy Technology Data Exchange (ETDEWEB)

Stepinski, Tadeusz (ed.); Ping Wu; Wennerstroem, Erik [Uppsala Univ. (Sweden). Signals and Systems

2004-09-01

This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2003/2004. After a short introduction a review of beam forming fundamentals required for proper understanding phased array operation is included. The factors that determine lateral resolution during ultrasonic imaging of flaws in solids are analyzed and results of simulations modelling contact inspection of copper are presented. In the second chapter an improved synthetic aperture imaging (SAI) technique is introduced. The proposed SAI technique is characterized by an enhanced lateral resolution compared with the previously proposed extended synthetic aperture focusing technique (ESAFT). The enhancement of imaging performance is achieved due to more realistic assumption concerning the probability density function of scatterers in the region of interest. The proposed technique takes the form of a two-step algorithm using the result obtained in the first step as a prior for the second step. Final chapter contains summary of our recent experimental and theoretical research on nonlinear ultrasonics of unbounded interfaces. A new theoretical model for rough interfaces is developed, and the experimental results from the copper specimens that mimic contact cracks of different types are presented. Derivation of the theory and selected measurement results are given in appendix.

Application of ultrasonic inspection technique for crack depth sizing on nickel based alloy weld. Part 3. Establishment of UT procedure for crack depth sizing by phased array UT

International Nuclear Information System (INIS)

Hirasawa, Taiji; Okada, Hisao; Fukutomi, Hiroyuki

2012-01-01

Recently, it is reported that the primary water stress corrosion cracking (PWSCC) was occurred at the nickel based alloy weld components such as steam generator safe end weld, reactor vessel safe end weld, and so on, in PWR. Defect detection and sizing is important in order to ensure the reliable operation and life extension of nuclear power plants. In the reactor vessel safe end weld, it was impossible to measure crack depth of PWSCC. The crack was detected in the axial direction of the safe end weld. Furthermore, the crack had some features such as shallow, large aspect ratio (ratio of crack depth and length), sharp geometry of crack tip, and so on. Therefore, development and improvement of defect detection and sizing capabilities for ultrasonic testing (UT) is required. Phased array technique was applied to nickel based alloy weld specimen with SCC cracks. From the experimental results, good accuracy of crack depth sizing by phased array UT for the inside inspection was shown. From these results, UT procedure for crack depth sizing was verified. Therefore, effectiveness of phased array UT for crack depth sizing in the nickel based alloy welds was shown. (author)

Development of phased array UT procedure for crack depth sizing on nickel based alloy weld

International Nuclear Information System (INIS)

Hirasawa, Taiji; Okada, Hisao; Fukutomi, Hiroyuki

2012-01-01

Recently, it is reported that the primary water stress corrosion cracking (PWSCC) has been occurred at the nickel based alloy weld components such as steam generator safe end weld, reactor vessel safe end weld, and so on, in PWR. Defect detection and sizing is important in order to ensure the reliable operation and life extension of nuclear power plants. In the reactor vessel safe end weld, it was impossible to measure crack depth of PWSCC. The crack was detected in the axial direction of the safe end weld. Furthermore, the crack had some features such as shallow, large aspect ratio (ratio of crack depth and length), sharp geometry of crack tip, and so on. Therefore, development and improvement of defect detection and sizing capabilities for ultrasonic inspection technique is required. Phased array UT technique was applied to nickel based alloy weld specimen with SCC cracks. From the experimental results, good accuracy of crack depth sizing by phased array UT for the inside inspection was shown. From these results, UT procedure for crack depth sizing was verified. Therefore, effectiveness of phased array UT for crack depth sizing in the nickel based alloy welds was shown. (author)

A Study on Techniques for Focusing Circumferential Array Guided Waves for Long Range Inspection of Pipes

International Nuclear Information System (INIS)

Kang, To; Kim, Hak Joon; Song, Sung Jin; Cho, Young Do; Lee, Dong Hoon; Cho, Hyun Joon

2009-01-01

Ultrasonic guided waves have been widely utilized for long range inspection of structures. Especially, development of array guided waves techniques and its application for long range gas pipe lines(length of from hundreds meters to few km) were getting increased. In this study, focusing algorithm for array guided waves was developed in order to improve long range inspectability and accuracy of the array guided waves techniques for long range inspection of gas pipes, and performance of the developed techniques was verified by experiments using the developed array guided wave system. As a result, S/N ratio of array guided wave signals obtained with the focusing algorithm was increased higher than that of signals without focusing algorithm

Simulation of 3-D radiation beam patterns propagated through a planar interface from ultrasonic phased array transducers.

Science.gov (United States)

Song, Sung-Jin; Kim, Chang-Hwan

2002-05-01

Phased array transducers are quite often mounted on solid wedges with specific angles in many practical ultrasonic inspections of thin plates phased array techniques with testing set-up, it is essential to have thorough understanding on the characteristics of radiation beam pattern produced in the interrogated medium. To address such a need, this paper proposes a systematic way to calculate full 3-D radiation beam patterns produced in the interrogated solid medium by phased array transducers mounted on a solid wedge. In order to investigate the characteristics of radiation beam patterns in steel, simulation is carried out for 7.5 MHz array transducers mounted on an acrylic wedge with the angle of 15.45 degrees with various of steering angles and/or focal planes.

Phased array concept for the ultrasonic inservice inspection at the spherical bottom of BWR-pressure vessels

International Nuclear Information System (INIS)

Brekow, G.; Wuestenberg, H.; Moehrle, W.; Schulz, E.

1987-01-01

The required enhancement of the integrity assessment of perforated reactor vessel base plates has been achieved by a phased-array concept. This technique improvement is based on the fact that the quantity of individual resonant components is reduced whilst increasing the amount of web regions which fall into the sonic range of the pivoted detector due to the larger apex angle scope which the phased array concept provides. A mathematical model concept was initially developed to determine the acoustic irradiation angle and squiat angle ranges to be detected by the phased-array scanner. A prototype of this device has been constructed and tested with a steel sample possessing different perforations and experimental reflectors in order to assess and optimize the new system. The results of these investigations are presented together with those of an application at the nuclear power station in Brunsbuettel. (orig./DG) [de

A novel ultrasonic phased array inspection system to NDT for offshore platform structures

Science.gov (United States)

Wang, Hua; Shan, Baohua; Wang, Xin; Ou, Jinping

2007-01-01

A novel ultrasonic phased array detection system is developed for nondestructive testing (NDT). The purpose of the system is to make acquisition of data in real-time from 64-element ultrasonic phased array transducer, and to enable real- time processing of the acquired data. The system is composed of five main parts: master unit, main board, eight transmit/receive units, a 64-element transducer and an external PC. The system can be used with 64 element transducers, excite 32 elements, receive and sample echo signals form 32 elements simultaneously at 62.5MHz with 8 bit precision. The external PC is used as the user interface showing the real time images and controls overall operation of the system through USB serial link. The use of Universal Serial Bus (USB) improves the transform speed and reduces hardware interface complexity. The program of the system is written in Visual C++.NET and is platform independent.

Application of Ultrasonic Phased Array Technology to the Detection of Defect in Composite Stiffened-structures

Science.gov (United States)

Zhou, Yuan-Qi; Zhan, Li-Hua

2016-05-01

Composite stiffened-structure consists of the skin and stringer has been widely used in aircraft fuselage and wings. The main purpose of the article is to detect the composite material reinforced structure accurately and explore the relationship between defect formation and structural elements or curing process. Based on ultrasonic phased array inspection technology, the regularity of defects in the manufacture of composite materials are obtained, the correlation model between actual defects and nondestructive testing are established. The article find that the forming quality of deltoid area in T-stiffened structure is obviously improved by pre-curing, the defects of hat-stiffened structure are affected by the mandrel. The results show that the ultrasonic phased array inspection technology can be an effectively way for the detection of composite stiffened-structures, which become an important means to control the defects of composite and improve the quality of the product.

Phase-enhanced defect sensitivity for EUV mask inspection

Science.gov (United States)

Wang, Yow-Gwo; Miyakawa, Ryan; Chao, Weilun; Goldberg, Kenneth; Neureuther, Andy; Naulleau, Patrick

2014-10-01

In this paper, we present a complete study on mask blank and patterned mask inspection utilizing the Zernike phase contrast method. The Zernike phase contrast method provides in-focus inspection ability to study phase defects with enhanced defect sensitivity. However, the 90 degree phase shift in the pupil will significantly reduce the amplitude defect signal at focus. In order to detect both types of defects with a single scan, an optimized phase shift instead of 90 degree on the pupil plane is proposed to achieve an acceptable trade-off on their signal strengths. We can get a 70% of its maximum signal strength at focus for both amplitude and phase defects with a 47 degree phase shift. For SNR, the tradeoff between speckle noise and signal strength has to be considered. The SNR of phase and amplitude defects at focus can both reach 11 with 13 degree phase shift and 50% apodization. Moreover, the simulation results on patterned mask inspection of partially hidden phase defects with die-to-database inspection approach on the blank inspection tool show that the improvement of the Zernike phase method is more limited. A 40% enhancement of peak signal strength can be achieved with the Zernike phase contrast method when the defect is centered in the space, while the enhancement drops to less than 10% when it is beneath the line.

Recent advances in automated ultrasonic inspection of Magnox power stations

International Nuclear Information System (INIS)

Wooldridge, A.B.

2006-01-01

Magnox Electric operates a number of Magnox nuclear power stations, some of which have presented difficult inspection challenges. This paper will describe recent advances in automated ultrasonic techniques which have enabled additional, fully effective and qualified inspections to be introduced. The examples chosen involve phased array inspection of fillet welds and the introduction of 3D data display and analysis using NDT Workbench. Ultrasonic phased arrays have been optimised for inspection of fillet welded structures where physical access for the operator is very awkward and the surfaces available for probe scanning are very restricted. In addition to controlling the beam direction and focus depth, the systems have also optimised the depth of field by varying the number of phased array elements fired at a given time. These phased array inspections are substantially superior in quality, reliability and speed compared with that achievable by conventional manual inspection. Analysis of automated ultrasonic data can be very time-consuming if defects are complex. NDT Workbench significantly improves data analysis for complex geometries and defects primarily because of the 3D data displays of multiple beams and automated logging of measurements. This system has been used in 2005 for data analysis of complex defects where sizing accuracy was particularly important. Both these inspection procedures have been formally qualified using the ENIQ (European Network for Inspection Qualification) Methodology. Such qualification was achieved more easily because of the rigorous in house training programmes established in each case and because the Technical Justifications referred to evidence from previous related qualifications whenever appropriate. The timely achievement of inspection qualification demonstrates that the new systems have reached sufficient maturity to be used with confidence for high quality inspections. (orig.)

Employing innovative techniques to reduce inspection times

International Nuclear Information System (INIS)

Heumueller, R.; Guse, G.; Dirauf, F.; Fischer, E.

1997-01-01

Shorter inspection periods mean lower revision costs and less tight revision schedules, but must not detract from the quality of inspection findings. This requirement imposes upon the company performing the inspection the need for top achievements both in quality management and in the use of innovative techniques. Flexible equipment systems and inspection techniques adapted to specific purposes are able to reduce inspection times in many inspection jobs. As part of a complete system designed to reduce inspection times, the new Saphir (Siemens Alok Phased Array Integrated Reliable UT-System) inspection equipment system is the core of most of the recent innovations. Being an integrated inspection equipment system, it is able to handle conventional US probes as well as arrays and phased arrays. It is open for further matching to specific inspection and administrative requirements and developments, and it may be incorporated in the network of an integrated system with a database. A technological leap in probe design in the past few years has allowed controllable wave fields to be generated which are in no way inferior to those of conventional probes with fixed angles of incidence. In this way, a number of inspection techniques can be implemented with a single probe. This reduces inspection times, setup and retooling times, and doses. Typical examples already used in practice are the LLT (longitudinal-longitudinal-transverse waves) technique and the integration of inspections for longitudinal and transverse defects in a single run. In the near future, surfaces with complicated curvatures will be inspected by novel modular robot systems consisting of individual modules of linear axes and rotational axes. (orig.) [de

Phased Array Imaging of Complex-Geometry Composite Components.

Science.gov (United States)

Brath, Alex J; Simonetti, Francesco

2017-10-01

Progress in computational fluid dynamics and the availability of new composite materials are driving major advances in the design of aerospace engine components which now have highly complex geometries optimized to maximize system performance. However, shape complexity poses significant challenges to traditional nondestructive evaluation methods whose sensitivity and selectivity rapidly decrease as surface curvature increases. In addition, new aerospace materials typically exhibit an intricate microstructure that further complicates the inspection. In this context, an attractive solution is offered by combining ultrasonic phased array (PA) technology with immersion testing. Here, the water column formed between the complex surface of the component and the flat face of a linear or matrix array probe ensures ideal acoustic coupling between the array and the component as the probe is continuously scanned to form a volumetric rendering of the part. While the immersion configuration is desirable for practical testing, the interpretation of the measured ultrasonic signals for image formation is complicated by reflection and refraction effects that occur at the water-component interface. To account for refraction, the geometry of the interface must first be reconstructed from the reflected signals and subsequently used to compute suitable delay laws to focus inside the component. These calculations are based on ray theory and can be computationally intensive. Moreover, strong reflections from the interface can lead to a thick dead zone beneath the surface of the component which limits sensitivity to shallow subsurface defects. This paper presents a general approach that combines advanced computing for rapid ray tracing in anisotropic media with a 256-channel parallel array architecture. The full-volume inspection of complex-shape components is enabled through the combination of both reflected and transmitted signals through the part using a pair of arrays held in a yoke

Investigation of UT procedure for crack depth sizing by phased array UT in Ni-based alloy weld

International Nuclear Information System (INIS)

Hirasawa, Taiji; Fukutomi, Hiroyuki

2013-01-01

Recently, it has been reported that the primary water stress corrosion cracking (PWSCC) has occurred in nickel based alloy weld components such as steam generator safe end weld, reactor vessel safe end weld, and so on, in PWR. Defect detection and sizing are important in order to ensure the reliable operation and life extension of nuclear power plants. In the reactor vessel safe end weld, it was impossible to measure crack depth of PWSCC. The cracks have occurred in the axial direction of the safe end weld. Furthermore, the cracks had some features such as deep, large aspect ratio (ratio of crack depth and length), sharp geometry of crack tip, and so on. Therefore, development and improvement of defect depth sizing capabilities by ultrasonic testing (UT) have been required. Phased array UT technique was applied with regard to defect depth sizing at the inside inspection in Ni-based alloy welds. Phased array UT was examined a standard block specimen with side drilled holes (SDHs). From the experimental results, the performance of linear array probes and dual matrix array probe were investigated. In the basis of the results, UT procedure for defect depth sizing was investigated and proposed. The UT procedure was applied to the defect depth measurement in Ni-based alloy weld specimen with electric discharge machine (EDM) notches. From these results, good accuracy of defect depth sizing by phased array UT for the inside inspection was shown. Therefore, it was clarified the effectiveness of the UT procedure for defect depth sizing in Ni-based alloy weld. (author)

Ultrasonic inspection of AA6013 laser welded joints

Directory of Open Access Journals (Sweden)

Adriano Passini

2011-09-01

Full Text Available Interest in laser beam welding for aerospace applications is continuously growing, mainly for aluminum alloys. The joints quality is usually assessed by non-destructive inspection (NDI. In this work, bead on plate laser welds on 1.6 mm thick AA6013 alloy sheets, using a 2 kW Yb-fiber laser were obtained and inspected by pulse/echo ultrasonic phased-array technique. Good and poor quality welds were inspected in order to verify the limits of inspection, comparing also to X-ray radiography and metallographic inspections. The results showed that ultrasonic phased array technique was able to identify the presence of grouped porosity, through the attenuation of the amplitude of the echo signal. This attenuation is attributed to the scattering of the waves caused by micro pores, with individual size below the resolution limit of the equipment, but when grouped, can cause a perceptive effect on the reflection spectra.

Characterisation of ultrasonic structural noise in multiple scattering media using phased arrays

International Nuclear Information System (INIS)

Bedetti, T; Dorval, V; Jenson, F; Derode, A

2013-01-01

The ultrasonic inspection of multiple scattering media gives rise to structural noise which makes it difficult to detect potential damage or crack inside the component. In order to predict the performances of ultrasonic inspection over such complex media, scattering models can be used. Such models rely on specific key parameters describing the multiple scattering process, which can be determined by specific measurements and post-processing techniques. Such experiments were carried out on stainless steel plates using linear phased-arrays. They consist in recording the response matrix constituted by impulse responses between all the elements of the array. By conducting post-processing on this matrix, we measure the elastic mean free path l e and the correlation distance d c of the recorded noise. Additionally, the dynamic behaviour of the coherent backscattering effect was studied in order to measure the diffusion constant D. Plane-wave beamforming has been applied to the response matrix to improve the angular resolution and the signal-to-noise ratio of the backscattered intensity. Details of postprocessing techniques will be shown

Non-destructive ultrasonic techniques for classifying and reconstructing defects; ALOK, phased arrays, holography-SAFT

International Nuclear Information System (INIS)

Hoeller, P.; Schmitz, V.; Mueller, W.; Gebhardt, W.; Barbian, O.A.

1983-01-01

The only way to achieve ultrasonic testing methods capable of reconstructing defects or inhomogeneities is to measure those data that are related to the geometry of the reflector. These are phase and time-of-flight as a function of the locus of incidence. For this purpose several synthetic aperture methods have been developed in recent years by our institute: ALOK and phased arrays as searching and analysing systems, especially for in-service inspection of nuclear power plants; and holography and SAFT as analysing systems. Their ability to detect, localize, classify and reconstruct defects is discussed. (author)

Simulation assisted pod of a phased array ultrasonic inspection in manufacturing

Science.gov (United States)

Dominguez, N.; Feuillard, V.; Jenson, F.; Willaume, P.

2012-05-01

The concept of Probability of Detection (POD) is generally used to quantitatively assess performances and reliability of NDT operations for in-service operations related to damage tolerant designs. Application of the POD approach as a metric for manufacturing NDT assessment would also be relevant but the very expensive cost of such campaigns generally prevents us from doing so. However the increase in NDT simulation capability and maturity opens the field for POD demonstrations for manufacturing NDT with the help of simulation. This paper presents the example of an automated phased array ultrasonic testing procedure of Electron Beam Welding on rotative parts, as part of the PICASSO European project. POD is calculated by using the uncertainty propagation approach in CIVA. The peculiarity of uncertainties in automated NDT compared to in-service manual operations is discussed and raises questions on appropriate statistics to be used for this kind of data. Alternative estimation techniques like Box-Cox transform or quantile regression are proposed and evaluated.

Antennas for Frequency Reconfigurable Phased Arrays

NARCIS (Netherlands)

Haider, S.N.

2015-01-01

Sensors such as phased array radars play a crucial role in public safety. They are unavoidable for surveillance, threat identification and post-disaster management. However, different scenarios impose immensely diverse requirements for these systems. Phased array systems occupy a large space. In

A characteristics of the small crack evaluation technique by triangle method with phased array UT

International Nuclear Information System (INIS)

Cho, Yong Sang

2005-01-01

Ultrasonic testing is a kind of nondestructive test to detect a crack or discontinuity in material or material surface by sending ultrasound to it. This conventional ultrasonic test has some difficulties to detect crack or inspect material specially in the case of complex-shaped power plant components such as Turbine blade root. Phased array UT system and its application methods for complex shaped power plant components will be a good alternative method which overcome present UT weakness. This study was aimed at developing a new method for finding the crack on material or material structures, and especially for determining the crack length without moving transducer. Especially ultrasonic phased array with electronic scan technique was used in carrying out both sizing and detect ability of crack as its depth and length changes. The response of ultrasonic phased array was analyzed to obtain the special method of determining crack length without moving the transducer and detect-ability of crack minimal length and depth from the material. The result showed a newly developed method for crack length determining is very real method which has its accuracy and verify the effectiveness of method compared to a conventional crack length determining method

Intracavitary ultrasound phased arrays for thermal therapies

Science.gov (United States)

Hutchinson, Erin

Currently, the success of hyperthermia and thermal surgery treatments is limited by the technology used in the design and fabrication of clinical heating devices and the completeness of the thermometry systems used for guidance. For both hyperthermia and thermal surgery, electrically focused ultrasound generated by phased arrays provides a means of controlling localized energy deposition in body tissues. Intracavitary applicators can be used to bring the energy source close to a target volume, such as the prostate, thereby minimizing normal tissue damage. The work performed in this study was aimed at improving noninvasive prostate thermal therapies and utilized three research approaches: (1) Acoustic, thermal and optimization simulations, (2) Design and fabrication of multiple phased arrays, (3) Ex vivo and in vivo experimental testing of the heating capabilities of the phased arrays. As part of this study, a novel aperiodic phased array design was developed which resulted in a 30- 45% reduction in grating lobe levels when compared to conventional phased arrays. Measured acoustic fields generated by the constructed aperiodic arrays agreed closely with the fields predicted by the theoretical simulations and covered anatomically appropriate ranges. The power capabilities of these arrays were demonstrated to be sufficient for the purposes of hyperthermia and thermal surgery. The advantage of using phased arrays in place of fixed focus transducers was shown by demonstrating the ability of electronic scanning to increase the size of the necrosed tissue volume while providing a more uniform thermal dose, which can ultimately reduce patient treatment times. A theoretical study on the feasibility of MRI (magnetic resonance imaging) thermometry for noninvasive temperature feedback control was investigated as a means to improve transient and steady state temperature distributions achieved in hyperthermia treatments. MRI guided ex vivo and in vivo experiments demonstrated

FY16 Status of Immersion Phased Array Ultrasonic Probe Development and Performance Demonstration Results for Under Sodium Viewing

International Nuclear Information System (INIS)

Diaz, Aaron A.; Chamberlin, Clyde E.; Edwards, Matthew K.; Hagge, Tobias J.; Hughes, Michael S.; Larche, Michael R.; Mathews, Royce A.; Neill, Kevin J.; Prowant, Matthew S.

2016-01-01

This section of the Joint summary technical letter report (TLR) describes work conducted at the Pacific Northwest National Laboratory (PNNL) during FY 2016 (FY16) on the under-sodium viewing (USV) PNNL project 58745, work package AT-16PN230102. This section of the TLR satisfies PNNL's M3AT-16PN2301025 milestone and is focused on summarizing the design, development, and evaluation of two different phased-array ultrasonic testing (PA-UT) probe designs - a two-dimensional (2D) matrix phased-array probe, and two one-dimensional (1D) linear array probes, referred to as serial number 4 (SN4) engineering test units (ETUs). The 2D probe is a pulse-echo (PE), 32x2, 64-element matrix phased-array ETU. The 1D probes are 32x1 element linear array ETUs. This TLR also provides the results from a performance demonstration (PD) of in-sodium target detection trials at 260°C using both probe designs. This effort continues the iterative evolution supporting the longer term goal of producing and demonstrating a pre-manufacturing prototype ultrasonic probe that possesses the fundamental performance characteristics necessary to enable the development of a high-temperature sodium-cooled fast reactor (SFR) inspection system for in-sodium detection and imaging.

FY16 Status of Immersion Phased Array Ultrasonic Probe Development and Performance Demonstration Results for Under Sodium Viewing

Energy Technology Data Exchange (ETDEWEB)

Diaz, Aaron A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chamberlin, Clyde E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Edwards, Matthew K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hagge, Tobias J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hughes, Michael S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larche, Michael R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mathews, Royce A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Neill, Kevin J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Prowant, Matthew S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-08-31

This section of the Joint summary technical letter report (TLR) describes work conducted at the Pacific Northwest National Laboratory (PNNL) during FY 2016 (FY16) on the under-sodium viewing (USV) PNNL project 58745, work package AT-16PN230102. This section of the TLR satisfies PNNL’s M3AT-16PN2301025 milestone and is focused on summarizing the design, development, and evaluation of two different phased-array ultrasonic testing (PA-UT) probe designs—a two-dimensional (2D) matrix phased-array probe, and two one-dimensional (1D) linear array probes, referred to as serial number 4 (SN4) engineering test units (ETUs). The 2D probe is a pulse-echo (PE), 32×2, 64-element matrix phased-array ETU. The 1D probes are 32×1 element linear array ETUs. This TLR also provides the results from a performance demonstration (PD) of in-sodium target detection trials at 260°C using both probe designs. This effort continues the iterative evolution supporting the longer term goal of producing and demonstrating a pre-manufacturing prototype ultrasonic probe that possesses the fundamental performance characteristics necessary to enable the development of a high-temperature sodium-cooled fast reactor (SFR) inspection system for in-sodium detection and imaging.

Phase retrieval in near-field measurements by array synthesis

DEFF Research Database (Denmark)

Wu, Jian; Larsen, Flemming Holm

1991-01-01

The phase retrieval problem in near-field antenna measurements is formulated as an array synthesis problem. As a test case, a particular synthesis algorithm has been used to retrieve the phase of a linear array......The phase retrieval problem in near-field antenna measurements is formulated as an array synthesis problem. As a test case, a particular synthesis algorithm has been used to retrieve the phase of a linear array...

Brazilian Decimetric Array (BDA) project - Phase II

Science.gov (United States)

Faria, C.; Stephany, S.; Sawant, H. S.; Cecatto, J. R.; Fernandes, F. C. R.

2010-02-01

The configuration of the second phase of the Brazilian Decimetric Array (BDA), installed at Cachoeira Paulista, Brazil (Longitude 45° 0‧ 20″ W and Latitude 22° 41‧ 19″ S), is a T-shaped array where 21 antennas are being added to existing 5 antennas of the first phase. In the third phase, in each arm of the T array, four more antennas will be added and baselines will be increased to 2.5 × 1.25 km in east-west and south directions, respectively. The antennas will be equally spaced at the distances of 250 meters from the central antenna of the T-array. Also, the frequency range will be increased to 1.2-1.7, 2.8 and 5.6 GHz. The Second phase of the BDA should be operational by the middle of 2010 and will operate in the frequency range of (1.2-1.7) GHz for solar and non solar observations. Here, we present the characteristics of the second phase of the BDA project, details of the array configuration, the u-v coverage, the synthesized beam obtained for the proposed configuration.

A case study of the crack sizing performance of the Ultrasonic Phased Array combined crack and wall loss inspection tool on the Centennial pipeline, the defect evaluation, including the defect evaluation, field feature verification and tool performance validation (performed by Marathon Oil, DNV and GE Oil and Gas)

Energy Technology Data Exchange (ETDEWEB)

Hrncir, T.; Turner, S. [Marathon Pipe Line LLC, Findley, OH (United States); Polasik, SJ [DNV Columbus, Inc, Dublin, OH 43017 (United States); Vieth, P. [BP EandP, Houston, TX (United States); Allen, D.; Lachtchouk, I.; Senf, P.; Foreman, G. [GE Oil and Gas PII Pipeline Solutions, Stutensee (Germany)], email: geoff.foreman@ge.com

2010-07-01

The Centennial Pipeline System is operated by Marathon Pipe Line LLC. It is 754 miles long and carries liquid products from eastern Texas to southern Illinois. Most of it was constructed in 1951 for natural gas, but it was converted in 2001 for liquid product service. GE Oil and Gas conducted an ultrasonic phased array in-line inspection (ILI) survey of this pipeline, whose primary purpose was to detect and characterize stress corrosion cracking. A dig verification was performed in 2008 to increase the level of confidence in the detection and depth-sizing capabilities of this inspection method. This paper outlines of the USCD technology and experience and describes how the ILI survey results were validated, how the ILI data analysis was improved, and the impact on managing the integrity of the line section. Results indicate that the phased array technology approached a 90% certainty predicted depth with a tolerance of 1 mm at a 95% confidence level.

Phased antenna arrays for fast wave power generation

International Nuclear Information System (INIS)

Bosia, G.; Jacquinot, J.

1991-01-01

A method for the generation of travelling waves in the Ion Cyclotron frequency range in JET is presented. The success of the method relies on the control of the array toroidal current, which in turn, is obtained by a coordinated vectorial control of the array power sources and tuning networks. This method has general application to present and future ICRF arrays. For uninterrupted, periodically fed and resonant toroidal arrays, phased operation requires only conventional tuning devices. For localised arrays, phased operation is inefficient at low plasma coupling. This inefficiency can be however removed with the addition of external coupling structures either at the antenna or at the generator ends. The performances of JET A1 antennae in phased operation is presented. The design philosophy for the JET A2 phased arrays is also discussed. These methods are applicable and extensible to Next Step Devices design

Ferrite LTCC based phased array antennas

KAUST Repository

Ghaffar, Farhan A.

2016-11-02

Two phased array antennas realized in multilayer ferrite LTCC technology are presented in this paper. The use of embedded bias windings in these designs allows the negation of external magnets which are conventionally employed with bulk ferrite medium. This reduces the required magnetostatic field strength by 90% as compared to the traditional designs. The phase shifters are implemented using the SIW technology. One of the designs is operated in the half mode waveguide topology while the other design is based on standard full mode waveguide operation. The two phase shifter designs are integrated with two element patch antenna array and slotted SIW array respectively. The array designs demonstrate a beam steering of 30° and ±19° respectively for a current excitation of 200 mA. The designs, due to their small factor can be easily integrated in modern communication systems which is not possible in the case of bulk ferrite based designs.

Array Phase Shifters: Theory and Technology

Science.gov (United States)

Romanofsky, Robert R.

2007-01-01

While there are a myriad of applications for microwave phase shifters in instrumentation and metrology, power combining, amplifier linearization, and so on, the most prevalent use is in scanning phased-array antennas. And while this market continues to be dominated by military radar and tracking platforms, many commercial applications have emerged in the past decade or so. These new and potential applications span low-Earth-orbit (LEO) communications satellite constellations and collision warning radar, an aspect of the Intelligent Vehicle Highway System or Automated Highway System. In any case, the phase shifters represent a considerable portion of the overall antenna cost, with some estimates approaching 40 percent for receive arrays. Ferrite phase shifters continue to be the workhorse in military-phased arrays, and while there have been advances in thin film ferrite devices, the review of this device technology in the previous edition of this book is still highly relevant. This chapter will focus on three types of phase shifters that have matured in the past decade: GaAs MESFET monolithic microwave integrated circuit (MMIC), micro-electromechanical systems (MEMS), and thin film ferroelectric-based devices. A brief review of some novel devices including thin film ferrite phase shifters and superconducting switches for phase shifter applications will be provided. Finally, the effects of modulo 2 phase shift limitations, phase errors, and transient response on bit error rate degradation will be considered.

Reconfigurable Wave Velocity Transmission Lines for Phased Arrays

Science.gov (United States)

Host, Nick; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix

2013-01-01

Phased array antennas showcase many advantages over mechanically steered systems. However, they are also more complex, heavy and most importantly costly. This presentation paper presents a concept which overcomes these detrimental attributes by eliminating all of the phase array backend (including phase shifters). Instead, a wave velocity reconfigurable transmission line is used in a series fed array arrangement to allow phase shifting with one small (100mil) mechanical motion. Different configurations of the reconfigurable wave velocity transmission line are discussed and simulated and experimental results are presented.

Apparative developments for inservice inspections of reactor pressure vessels

International Nuclear Information System (INIS)

Bohn, H.; Ruthrof, K.; Barbian, O.A.; Kappes, W.; Neumann, R.; Stanger, H.K.

1987-01-01

Emphasizing PWR pressure vessel (RPV) inspections, recent developments of new generations of automated and mechanized ultrasonic inspection equipment are presented. Starting from general equipment design and inservice implenentation criteria, specific examples are given. Main attention is directed to equipment realization of phased array and ALOK inspection techniques, especially in their combination. Refined aspects of subsequent computer processing and evaluation of defect detection data are described. Analytical features and potential for further developments become evident. Remote controlled RPV inspections are stressed by describing a new generation of central mast manipulators, forming an integral part of total inservice inspection system. (orig./HP)

A Study on a Crack Evaluation Technique for Turbine Blade Root Using Phased Array Ultrasonics

International Nuclear Information System (INIS)

Cho, Yong Sang; Jung, Gye Jo; Park, Sang Ki; Kim, Jae Hoon

2004-01-01

Ultrasonic testing is a kind of nondestructive test to detect a crack or discontinuity in materials or on material surfaces by sending ultrasound to it. This conventional ultrasonic technique has some limitations in reliably detecting crack or accurately assessing materials in the case of complex-shaped power plant components such as a turbine blade root. An alternative method for such a difficult inspection is highly needed. In this study, application of a phased array ultrasonic testing (UT) system to a turbine blade, one of the critical power plant components, has been considered, and the particular incident angle has been determined so that the greatest track detectability and the most accurate crack length evaluation nay be achieved. The response of ultrasonic phased array was also analyzed to establish a special method to determine the track length without moving the transducer. The result showed that the developed method for crack length assessment is a more accurate and effective method, compared with the conventional method

On the (Frequency) Modulation of Coupled Oscillator Arrays in Phased Array Beam Control

Science.gov (United States)

Pogorzelski, R.; Acorn, J.; Zawadzki, M.

2000-01-01

It has been shown that arrays of voltage controlled oscillators coupled to nearest neighbors can be used to produce useful aperture phase distributions for phased array antennas. However, placing information of the transmitted signal requires that the oscillations be modulated.

In-service inspection guidelines for composite aerospace structures

International Nuclear Information System (INIS)

Heida, Jaap H.; Platenkamp, Derk J.

2012-01-01

The in-service inspection of composite aerospace structures is reviewed, using the results of a evaluation of promising, mobile non-destructive inspection (NDI) methods. The evaluation made use of carbon fibre reinforced specimens representative for primary composite aerospace structures, including relevant damage types such as impact damage, delaminations and disbonds. A range of NDI methods were evaluated such as visual inspection, vibration analysis, phased array ultrasonic inspection, shearography and thermography inspection. Important aspects of the evaluation were the capability for defect detection and characterization, portability of equipment, field of view, couplant requirements, speed of inspection, level of training required and the cost of equipment. The paper reviews the damage tolerance design approach for composites, and concludes with guidelines for the in-service inspection of composite aerospace structures.

Development of electromagnetic acoustic transducer (EMAT) phased arrays for SFR inspection

Energy Technology Data Exchange (ETDEWEB)

Le Bourdais, Florian; Marchand, Benoît [CEA LIST, Centre de Saclay F-91191 Gif-sur-Yvette (France)

2014-02-18

A long-standing problem for Sodium cooled Fast Reactor (SFR) instrumentation is the development of efficient under-sodium visualization systems adapted to the hot and opaque sodium environment. Electromagnetic Acoustic Transducers (EMAT) are potential candidates for a new generation of Ultrasonic Testing (UT) probes well-suited for SFR inspection that can overcome drawbacks of classical piezoelectric probes in sodium environment. Based on the use of new CIVA simulation tools, we have designed and optimized an advanced EMAT probe for under-sodium visualization. This has led to the development of a fully functional L-wave EMAT sensing system composed of 8 elements and a casing withstanding 200° C sodium inspection. Laboratory experiments demonstrated the probe's ability to sweep an ultrasonic beam to an angle of 15 degrees. Testing in a specialized sodium facility has shown that it was possible to obtain pulse-echo signals from a target under several different angles from a fixed position.

Phase transition in a modified square Josephson-junction array

CERN Document Server

Han, J

1999-01-01

We study the phase transition in a modified square proximity-coupled Josephson-junction array with small superconducting islands at the center of each plaquette. We find that the modified square array undergoes a Kosterlitz-Thouless-Berezinskii-like phase transition, but at a lower temperature than the simple square array with the same single-junction critical current. The IV characteristics, as well as the phase transition, resemble qualitatively those of a disordered simple square array. The effects of the presence of the center islands in the modified square array are discussed.

An electromagnetic spherical phased array thermonuclear fusion reactor

International Nuclear Information System (INIS)

Okress, E.C.

1983-01-01

Discussed are salient physics aspects of a microwave singly reentrant spherical periodic phased array of uniformally distributed identical coaxial radiation elements in an essentially simulated infinite array environment. The array is capable of maintaining coherence or phase control (to the limit of the order of 300 GHz) of its spherically converging electromagnetic transverse magnetic mode radiation field, for confinement (and heating) of thermonuclear plasma in steady-state or inertial thermonuclear fusion. The array also incorporates capability for coaxial directional coupler extraction of fusionpower. The radiation elements of the array are shielded against DT Thermonuclear plasma emissions (i.e., neutrons and bremsstrahlung) by either sufficiently (available) low less tangent and cooled, spherically concentric shield (e.g., Titanium oxide); or alternately by identical material dome windows mounted on each radiation element's aperture of the array. The pump microwave power required for thermonuclear fusion feasibility comprises an array of phase-locked available klystron amplifiers (comparable gyratron amplifiers remain to be developed)

Phased-array design for MST and ST radars

Science.gov (United States)

Ecklund, W. L.

1986-01-01

All of the existing radar systems fully dedicated to clear-air radar studies use some type of phased-array antennas. The effects of beam-steering techniques including feed networks and phase shifters; sidelobe control; ground-clutter suppression; low altitude coverage; arrays with integrated radiating elements and feed networks; analysis of coaxial-collinear antennas; use of arrays with multiple beams; and array testing and measure on structural design of the antenna are discussed.

Validating eddy current array probes for inspecting steam generator tubes

International Nuclear Information System (INIS)

Sullivan, S.P.; Cecco, V.S.; Obrutsky, L.S.

1997-01-01

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves based on signal-to-noise studies using field data. Results of eddy current scans of tubes with laboratory-induced ODSCC are presented with associated POD curves. These studies appear promising in predicting realistic POD curves for new inspection technologies. They are being used to qualify an improved eddy current array probe in preparation for field use. (author)

A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor.

Science.gov (United States)

Zhang, Huayu; Xie, Fengqin; Cao, Maoyong; Zhong, Mingming

2017-07-01

To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA) sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor), magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

Design and control of phased ICRF antenna arrays

International Nuclear Information System (INIS)

Goulding, R.H.; Baity, F.W.; Hoffman, D.J.

1993-01-01

Phased antenna arrays operating in the ion cyclotron range of frequencies (ICRF) are used to produce highly directional wave spectra, primarily for use in current drive experiments. RF current drive using phased antennas has been demonstrated in both the JET and DIII-D tokamaks, and both devices are planning to operate new four-element arrays beginning early next year. Features of antenna design that are relevant to phased operation and production of directional spectra are reviewed. Recent advances in the design of the feed circuits and the related control systems for these arrays should substantially improve their performance, by reducing the coupling seen by the matching networks and rf power supplies caused by the mutual impedance of the array elements. The feed circuit designs for the DIII-D and JET phased antenna arrays are compared. The two configurations differ significantly due to the fact that one power amplifier is used for the entire array in the former case, and one per element in the latter. The JET system uses automatic feedback control of matching, phase and amplitude of antenna currents, and the transmitter power balance. The design of this system is discussed, and a time dependent model used to predict its behavior is described

Phased array antenna control

Science.gov (United States)

Doland, G. D. (Inventor)

1978-01-01

Several new and useful improvements in steering and control of phased array antennas having a small number of elements, typically on the order of 5 to 17 elements are provided. Among the improvements are increasing the number of beam steering positions, reducing the possibility of phase transients in signals received or transmitted with the antennas, and increasing control and testing capacity with respect to the antennas.

Proceedings of the Third EPRI Phased Array Ultrasound Seminar

International Nuclear Information System (INIS)

2003-01-01

Phased array technology for ultrasonic examination is providing innovative solutions for nuclear in-service examination applications. EPRI has been a prime mover in the development and deployment of phased array ultrasound applications in the domestic nuclear market over the past decade. As part of this strategic effort, EPRI has hosted a series of seminars on phased array technology and its applications

Remoting alternatives for a multiple phased-array antenna network

Science.gov (United States)

Shi, Zan; Foshee, James J.

2001-10-01

Significant improvements in technology have made phased array antennas an attractive alternative to the traditional dish antenna for use on wide body airplanes. These improvements have resulted in reduced size, reduced cost, reduced losses in the transmit and receive channels (simplifying the design), a significant extension in the bandwidth capability, and an increase in the functional capability. Flush mounting (thus reduced drag) and rapid beam switching are among the evolving desirable features of phased array antennas. Beam scanning of phased array antennas is limited to +/-45 degrees at best and therefore multiple phased array antennas would need to be used to insure instantaneous communications with any ground station (stations located at different geographical locations on the ground) and with other airborne stations. The exact number of phased array antennas and the specific installation location of each antenna on the wide body airplane would need to be determined by the specific communication requirements, but it is conceivable as many as five phased array antennas may need to be used to provide the required coverage. Control and switching of these antennas would need to be accomplished at a centralized location on the airplane and since these antennas would be at different locations on the airplane an efficient scheme of remoting would need to be used. To save in cost and keep the phased array antennas as small as possible the design of the phased array antennas would need to be kept simple. A dish antenna and a blade antenna (small size) could also be used to augment the system. Generating the RF signals at the central location and then using RF cables or waveguide to get the signal to any given antenna could result in significant RF losses. This paper will evaluate a number of remoting alternatives to keep the system design simple, reduce system cost, and utilize the functional capability of networking multiple phased array antennas on a wide body

A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

KAUST Repository

Nafe, Ahmed A.; Ghaffar, Farhan A.; Farooqui, Muhammad Fahad; Shamim, Atif

2016-01-01

In this work, we present a novel configuration for realizing monolithic SIW-based phased antenna arrays using Ferrite LTCC technology. Unlike the current common schemes for realizing SIW phased arrays that rely on surface-mount component (p-i-n diodes, etc) for controlling the phase of the individual antenna elements, here the phase is tuned by biasing of the ferrite filling of the SIW. This approach eliminates the need for mounting of any additional RF components and enables seamless monolithic integration of phase shifters and antennas in SIW technology. As a proof of concept, a two-element slotted SIW-based phased array is designed, fabricated and measured. The prototype exhibits a gain of 4.9 dBi at 13.2 GHz and a maximum E-plane beam-scanning of 28 degrees using external windings for biasing the phase shifters. Moreover, the array can achieve a maximum beam-scanning of 19 degrees when biased with small windings that are embedded in the package. This demonstration marks the first time a fully monolithic SIW-based phased array is realized in Ferrite LTCC technology and paves the way for future larger-size implementations.

A Ferrite LTCC-Based Monolithic SIW Phased Antenna Array

KAUST Repository

Nafe, Ahmed

2016-11-17

In this work, we present a novel configuration for realizing monolithic SIW-based phased antenna arrays using Ferrite LTCC technology. Unlike the current common schemes for realizing SIW phased arrays that rely on surface-mount component (p-i-n diodes, etc) for controlling the phase of the individual antenna elements, here the phase is tuned by biasing of the ferrite filling of the SIW. This approach eliminates the need for mounting of any additional RF components and enables seamless monolithic integration of phase shifters and antennas in SIW technology. As a proof of concept, a two-element slotted SIW-based phased array is designed, fabricated and measured. The prototype exhibits a gain of 4.9 dBi at 13.2 GHz and a maximum E-plane beam-scanning of 28 degrees using external windings for biasing the phase shifters. Moreover, the array can achieve a maximum beam-scanning of 19 degrees when biased with small windings that are embedded in the package. This demonstration marks the first time a fully monolithic SIW-based phased array is realized in Ferrite LTCC technology and paves the way for future larger-size implementations.

Probe suppression in conformal phased array

CERN Document Server

Singh, Hema; Neethu, P S

2017-01-01

This book considers a cylindrical phased array with microstrip patch antenna elements and half-wavelength dipole antenna elements. The effect of platform and mutual coupling effect is included in the analysis. The non-planar geometry is tackled by using Euler's transformation towards the calculation of array manifold. Results are presented for both conducting and dielectric cylinder. The optimal weights obtained are used to generate adapted pattern according to a given signal scenario. It is shown that array along with adaptive algorithm is able to cater to an arbitrary signal environment even when the platform effect and mutual coupling is taken into account. This book provides a step-by-step approach for analyzing the probe suppression in non-planar geometry. Its detailed illustrations and analysis will be a useful text for graduate and research students, scientists and engineers working in the area of phased arrays, low-observables and stealth technology.

A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor

Directory of Open Access Journals (Sweden)

Huayu Zhang

2017-07-01

Full Text Available To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor, magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

Evaluation and field validation of Eddy-Current array probes for steam generator tube inspection

International Nuclear Information System (INIS)

Dodd, C.V.; Pate, J.R.

1996-07-01

The objective of the Improved Eddy-Current ISI for Steam Generator Tubing program is to upgrade and validate eddy-current inspections, including probes, instrumentation, and data processing techniques for inservice inspection of new, used, and repaired steam generator tubes; to improve defect detection, classification, and characterization as affected by diameter and thickness variations, denting, probe wobble, tube sheet, tube supports, copper and sludge deposits, even when defect types and other variables occur in combination; to transfer this advanced technology to NRC's mobile NDE laboratory and staff. This report describes the design of specialized high-speed 16-coil eddy-current array probes. Both pancake and reflection coils are considered. Test results from inspections using the probes in working steam generators are given. Computer programs developed for probe calculations are also supplied

Free span burial inspection pig. Phase B

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-04-01

This report deals with design and construction of a pipeline pig for on-line internal inspection of offshore trenched gas pipelines for pipeline burial, free spans, exposures and loss of concrete weight coating. The measuring principle uses detection of the natural gamma radiation emitted by sea bed formations and the concrete coating of the pipe to map pipeline condition. The gamma ray flux penetrating to the internal side of the pipeline is an effect of the outside conditions. The measuring principle was confirmed in a occasionally present in the gas, blurred seriously sensor signals of the previous instrumentation. The continued project activities have been divided in two phases. Phase A comprised design and construction of a detector system, which could identify and quantify radioactive components from decay of radon-222. During Phase A a new gamma detector was tested in full scale exposed to radon-222. New data analysis procedures for the correction for the influence of radon-222 inside the pipeline, where developed and its utility successfully demonstrated. During Phase B the new detector was mounted in a pipeline pig constructed for inspection of 30-inch gas pipelines. Working conditions were demonstrated in three runs through the southern route of the DONG owned 30-inch gas pipelines crossing the Danish strait named the Great Belt. The FSB-technology found 88% of the free spans identified with the latest acoustic survey. The FSB-technology found in addition 22 free spans that were termed ''invisible'', because they were not identified by the most recent acoustic survey. It is believed that ''invisible free spans'' are either real free spans or locations, where the pipeline has no or very little support from deposits in the pipeline trench. The FSB-survey confirmed all exposed sections longer than 20 metres found by the acoustic survey in the first 21 kilometre of the pipeline. However, the FSB-survey underestimated

An Instrument for Inspecting Aspheric Optical Surfaces and Components, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This is a Phase II SBIR proposal to develop an extremely versatile optical inspection tool for aspheric optical components and optics that are not easily inspected...

A novel method to design sparse linear arrays for ultrasonic phased array.

Science.gov (United States)

Yang, Ping; Chen, Bin; Shi, Ke-Ren

2006-12-22

In ultrasonic phased array testing, a sparse array can increase the resolution by enlarging the aperture without adding system complexity. Designing a sparse array involves choosing the best or a better configuration from a large number of candidate arrays. We firstly designed sparse arrays by using a genetic algorithm, but found that the arrays have poor performance and poor consistency. So, a method based on the Minimum Redundancy Linear Array was then adopted. Some elements are determined by the minimum-redundancy array firstly in order to ensure spatial resolution and then a genetic algorithm is used to optimize the remaining elements. Sparse arrays designed by this method have much better performance and consistency compared to the arrays designed only by a genetic algorithm. Both simulation and experiment confirm the effectiveness.

Improved SNR of phased-array PERES coils via simulation study

International Nuclear Information System (INIS)

RodrIguez, Alfredo O; Medina, LucIa

2005-01-01

A computational comparison of signal-to-noise ratio (SNR) was performed between a conventional phased array of two circular-shaped coils and a petal resonator surface array. The quasi-static model and phased-array optimum SNR were combined to derive an SNR formula for each array. Analysis of mutual inductance between coil petals was carried out to compute the optimal coil separation and optimum number of petal coils. Mutual interaction between coil arrays was not included in the model because this does not drastically affect coil performance. Phased arrays of PERES coils show a 114% improvement in SNR over that of the simplest circular configuration. (note)

RCS estimation of linear and planar dipole phased arrays approximate model

CERN Document Server

Singh, Hema; Jha, Rakesh Mohan

2016-01-01

In this book, the RCS of a parallel-fed linear and planar dipole array is derived using an approximate method. The signal propagation within the phased array system determines the radar cross section (RCS) of phased array. The reflection and transmission coefficients for a signal at different levels of the phased-in scattering array system depend on the impedance mismatch and the design parameters. Moreover the mutual coupling effect in between the antenna elements is an important factor. A phased array system comprises of radiating elements followed by phase shifters, couplers, and terminating load impedance. These components lead to respective impedances towards the incoming signal that travels through them before reaching receive port of the array system. In this book, the RCS is approximated in terms of array factor, neglecting the phase terms. The mutual coupling effect is taken into account. The dependence of the RCS pattern on the design parameters is analyzed. The approximate model is established as a...

Code-modulated interferometric imaging system using phased arrays

Science.gov (United States)

Chauhan, Vikas; Greene, Kevin; Floyd, Brian

2016-05-01

Millimeter-wave (mm-wave) imaging provides compelling capabilities for security screening, navigation, and bio- medical applications. Traditional scanned or focal-plane mm-wave imagers are bulky and costly. In contrast, phased-array hardware developed for mass-market wireless communications and automotive radar promise to be extremely low cost. In this work, we present techniques which can allow low-cost phased-array receivers to be reconfigured or re-purposed as interferometric imagers, removing the need for custom hardware and thereby reducing cost. Since traditional phased arrays power combine incoming signals prior to digitization, orthogonal code-modulation is applied to each incoming signal using phase shifters within each front-end and two-bit codes. These code-modulated signals can then be combined and processed coherently through a shared hardware path. Once digitized, visibility functions can be recovered through squaring and code-demultiplexing operations. Pro- vided that codes are selected such that the product of two orthogonal codes is a third unique and orthogonal code, it is possible to demultiplex complex visibility functions directly. As such, the proposed system modulates incoming signals but demodulates desired correlations. In this work, we present the operation of the system, a validation of its operation using behavioral models of a traditional phased array, and a benchmarking of the code-modulated interferometer against traditional interferometer and focal-plane arrays.

Phased Array Radar Network Experiment for Severe Weather

Science.gov (United States)

Ushio, T.; Kikuchi, H.; Mega, T.; Yoshikawa, E.; Mizutani, F.; Takahashi, N.

2017-12-01

Phased Array Weather Radar (PAWR) was firstly developed in 2012 by Osaka University and Toshiba under a grant of NICT using the Digital Beamforming Technique, and showed a impressive thunderstorm behavior with 30 second resolution. After that development, second PAWR was installed in Kobe city about 60 km away from the first PAWR site, and Tokyo Metropolitan University, Osaka Univeristy, Toshiba and the Osaka Local Government started a new project to develop the Osaka Urban Demonstration Network. The main sensor of the Osaka Network is a 2-node Phased Array Radar Network and lightning location system. Data products that are created both in local high performance computer and Toshiba Computer Cloud, include single and multi-radar data, vector wind, quantitative precipitation estimation, VIL, nowcasting, lightning location and analysis. Each radar node is calibarated by the baloon measurement and through the comparison with the GPM (Global Precipitation Measurement)/ DPR (Dual Frequency Space borne Radar) within 1 dB. The attenuated radar reflectivities obtained by the Phased Array Radar Network at X band are corrected based on the bayesian scheme proposed in Shimamura et al. [2016]. The obtained high resolution (every 30 seconds/ 100 elevation angles) 3D reflectivity and rain rate fields are used to nowcast the surface rain rate up to 30 minutes ahead. These new products are transferred to Osaka Local Government in operational mode and evaluated by several section in Osaka Prefecture. Furthermore, a new Phased Array Radar with polarimetric function has been developed in 2017, and will be operated in the fiscal year of 2017. In this presentation, Phased Array Radar, network architecuture, processing algorithm, evalution of the social experiment and first Multi-Prameter Phased Array Radar experiment are presented.

Optically addressed ultra-wideband phased antenna array

Science.gov (United States)

Bai, Jian

Demands for high data rate and multifunctional apertures from both civilian and military users have motivated development of ultra-wideband (UWB) electrically steered phased arrays. Meanwhile, the need for large contiguous frequency is pushing operation of radio systems into the millimeter-wave (mm-wave) range. Therefore, modern radio systems require UWB performance from VHF to mm-wave. However, traditional electronic systems suffer many challenges that make achieving these requirements difficult. Several examples includes: voltage controlled oscillators (VCO) cannot provide a tunable range of several octaves, distribution of wideband local oscillator signals undergo high loss and dispersion through RF transmission lines, and antennas have very limited bandwidth or bulky sizes. Recently, RF photonics technology has drawn considerable attention because of its advantages over traditional systems, with the capability of offering extreme power efficiency, information capacity, frequency agility, and spatial beam diversity. A hybrid RF photonic communication system utilizing optical links and an RF transducer at the antenna potentially provides ultra-wideband data transmission, i.e., over 100 GHz. A successful implementation of such an optically addressed phased array requires addressing several key challenges. Photonic generation of an RF source with over a seven-octave bandwidth has been demonstrated in the last few years. However, one challenge which still remains is how to convey phased optical signals to downconversion modules and antennas. Therefore, a feed network with phase sweeping capability and low excessive phase noise needs to be developed. Another key challenge is to develop an ultra-wideband array antenna. Modern frontends require antennas to be compact, planar, and low-profile in addition to possessing broad bandwidth, conforming to stringent space, weight, cost, and power constraints. To address these issues, I will study broadband and miniaturization

Concept of an interlaced phased array for beam switching

Science.gov (United States)

Reddy, C. A.; Janardhanan, K. V.; Mukundan, K. K.; Shenoy, K. S. V.

1990-04-01

A novel concept is described for feeding and phasing a large linear array of N antenna elements using only three or five feed points and phase shifters and still achieving beam switching. The idea consists of drastically reducing the number of input points by interlacing a small number of serially fed subarrays which are suitably phased. This so-called interlaced phased array (IPA) concept was tested using an array of 15 four-element Yagi antennas with a spacing equal to 0.8 wavelengths and found feasible. Some of the distinct advantages of the IPA in comparison with a conventional system of beam switching are reduced power loss, reduced phasing errors, reduced cost, increased reliability resulting from greatly reduced number of phase shifters, and better symmetry of off-zenith beams.

Phased Array Ultrasonic Evaluation of Space Shuttle Main Engine (SSME) Nozzle Weld

Science.gov (United States)

James, Steve; Engel, J.; Kimbrough, D.; Suits, M.; Hopson, George (Technical Monitor)

2001-01-01

This viewgraph presentation gives an overview of the phased array ultrasonic evaluation of the Space Shuttle Main Engine (SSME) nozzle weld. Details are given on the nondestructive testing evaluation approach, conventional shear wave and phased array techniques, and an x-ray versus phased array risk analysis. The field set-up was duplicated to the greatest extent possible in the laboratory and the phased array ultrasonic technique was developed and validated prior to weld evaluation. Results are shown for the phased array ultrasonic evaluation and conventional ultrasonic evaluation results.

Intelligent mobile sensor system for drum inspection and monitoring: Phase 1

International Nuclear Information System (INIS)

1993-06-01

The objective of this project was to develop an operational system for monitoring and inspection activities for waste storage facility operations at several DOE sites. Specifically, the product of this effort is a robotic device with enhanced intelligence and maneuverability capable of conducting routine inspection of stored waste drums. The device is capable of operating in narrow aisles and interpolating the free aisle space between rows of stacked drums. The system has an integrated sensor suite for leak detection, and is interfaced with a site database both for inspection planning and for data correlation, updating, and report generation. The system is capable of departing on an assigned mission, collecting required data, recording which positions of its mission had to be aborted or modified due to environmental constraints, and reporting back when the mission is complete. Successful identification of more than 90% of all drum defects has been demonstrated in a high fidelity waste storage facility mockup. Identified anomalies included rust spots, rust streaks, areas of corrosion, dents, and tilted drums. All drums were positively identified and correlated with the site database. This development effort is separated into three phases of which phase one is now complete. The first phase has demonstrated an integrated system for monitoring and inspection activities for waste storage facility operations. This demonstration system was quickly fielded and evaluated by leveraging technologies developed from previous NASA and DARPA contracts and internal research. The second phase will demonstrate a prototype system appropriate for operational use in an actual storage facility. The prototype provides an integrated design that considers operational requirements, hardware costs, maintenance, safety, and robustness. The final phase will demonstrate commercial viability using the prototype vehicle in a pilot waste operations and inspection project

Evaluation of phased array UT conditions using ultrasonic visualization technique

International Nuclear Information System (INIS)

Furukawa, Takashi; Komura, Ichirou

2008-01-01

Phased array provides many advantages over conventional ultrasonic testing method, but phased array has also limitations. This paper describes typical results of the experimental sound field analysis generated from the array probe. A photo-elastic ultrasonic visualization technique was applied in this study. The sound fields of shear wave generated from the array probe was equivalent to that from the fixed angle probe. (author)

Blending of phased array data

Science.gov (United States)

Duijster, Arno; van Groenestijn, Gert-Jan; van Neer, Paul; Blacquière, Gerrit; Volker, Arno

2018-04-01

The use of phased arrays is growing in the non-destructive testing industry and the trend is towards large 2D arrays, but due to limitations, it is currently not possible to record the signals from all elements, resulting in aliased data. In the past, we have presented a data interpolation scheme `beyond spatial aliasing' to overcome this aliasing. In this paper, we present a different approach: blending and deblending of data. On the hardware side, groups of receivers are blended (grouped) in only a few transmit/recording channels. This allows for transmission and recording with all elements, in a shorter acquisition time and with less channels. On the data processing side, this blended data is deblended (separated) by transforming it to a different domain and applying an iterative filtering and thresholding. Two different filtering methods are compared: f-k filtering and wavefield extrapolation filtering. The deblending and filtering methods are demonstrated on simulated experimental data. The wavefield extrapolation filtering proves to outperform f-k filtering. The wavefield extrapolation method can deal with groups of up to 24 receivers, in a phased array of 48 × 48 elements.

Development of Inspection Technique for Socket Weld of Small Bore Piping in Nuclear Power Plant

International Nuclear Information System (INIS)

Yoon, Byungsik; Kim, Yongsik; Lee, Jeongseok

2013-01-01

The losses incurred by unplanned shutdowns are significant; consequently, early crack initiation and crack detection, including the detection of fillet weld manufacturing defects, is of the utmost importance. Current inspection techniques are not capable of reliably inspecting socket welds; therefore, new approaches are needed. The new technique must be sensitive to socket weld cracking, which usually initiates from the root, in order to detect the cracking during the early failure phase. In 2008, Kori unit 3 experienced leakage from the drain line socket weld of a steam generator. From this experience, KHNP enforced a management program to focus on enhancing the reliability of small bore socket weld piping inspections. Currently, conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. But there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD surface of small bore piping. In this study, phased array ultrasonic inspection techniques are applied to increase inspection speed and reliability. Additionally a manually encoded scanner has been developed to enhance contact conditions and maintain constant signal quality. A phased array UT technique and system was developed to inspect small bore socket welds. The experimental results show all artificial flaws in the specimen were detected and measured. These experimental results show, that the newly developed inspection system, has improved the reliability and speed of small bore socket weld inspection. Based on these results, future works shall focus on additional experiments, with more realistic flaw responses. By applying this technique to the field, we expect that it can improve the integrity of small bore piping in nuclear power plants

Ultrasonic Phased Array Techniques for Detection of Flaws of Stud Bolts in Nuclear Power Plants

International Nuclear Information System (INIS)

Lee, Joon Hyun; Choi, Sang Woo

2006-01-01

The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared

In-phased second harmonic wave array generation with intra-Talbot-cavity frequency-doubling.

Science.gov (United States)

Hirosawa, Kenichi; Shohda, Fumio; Yanagisawa, Takayuki; Kannari, Fumihiko

2015-03-23

The Talbot cavity is one promising method to synchronize the phase of a laser array. However, it does not achieve the lowest array mode with the same phase but the highest array mode with the anti-phase between every two adjacent lasers, which is called out-phase locking. Consequently, their far-field images exhibit 2-peak profiles. We propose intra-Talbot-cavity frequency-doubling. By placing a nonlinear crystal in a Talbot cavity, the Talbot cavity generates an out-phased fundamental wave array, which is converted into an in-phase-locked second harmonic wave array at the nonlinear crystal. We demonstrate numerical calculations and experiments on intra-Talbot-cavity frequency-doubling and obtain an in-phase-locked second harmonic wave array for a Nd:YVO₄ array laser.

Hierarchical sinuous-antenna phased array for millimeter wavelengths

Science.gov (United States)

Cukierman, Ari; Lee, Adrian T.; Raum, Christopher; Suzuki, Aritoki; Westbrook, Benjamin

2018-03-01

We present the design, fabrication, and measured performance of a hierarchical sinuous-antenna phased array coupled to superconducting transition-edge-sensor (TES) bolometers for millimeter wavelengths. The architecture allows for dual-polarization wideband sensitivity with a beam width that is approximately frequency-independent. We report on measurements of a prototype device, which uses three levels of triangular phased arrays to synthesize beams that are approximately constant in width across three frequency bands covering a 3:1 bandwidth. The array element is a lens-coupled sinuous antenna. The device consists of an array of hemispherical lenses coupled to a lithographed wafer, which integrates TESs, planar sinuous antennas, and microwave circuitry including band-defining filters. The approximately frequency-independent beam widths improve coupling to telescope optics and keep the sensitivity of an experiment close to optimal across a broad frequency range. The design can be straightforwardly modified for use with non-TES lithographed cryogenic detectors such as kinetic inductance detectors. Additionally, we report on the design and measurements of a broadband 180° hybrid that can simplify the design of future multichroic focal planes including but not limited to hierarchical phased arrays.

Heat exchanger tube inspection using ultrasonic arrays

International Nuclear Information System (INIS)

Meyer, P.A.; Carodiskey, T.J.

1986-01-01

Tubing used in industrial heat exchangers is often subject to failure caused by corrosion and cracking. Technical conferences are used as a forum in the steam generator industry to ensure that the failure mechanisms are well understood and that the quality of the heat exchanger is maintained. The quality of a heat exchanger can be thought of as its ability to operate to design specifications over its intended life. This is the motivation to inspect and evaluate these devices periodically. Inspection, however, normally requires shutdown of the heat exchanger which is costly but is much more acceptable than an unscheduled shutdown due to failure of a tube. Therefore, the degree of inspection is established by balancing the cost of inspection with the risk of a tube failure. Any method of reducing the cost of inspection will permit a higher degree of inspection and, therefore, improve heat exchanger quality. This paper reviews the design and performance of an improved method of ultrasonic inspection of heat exchanger tubing with emphasis on applications in the nuclear industry

Qualification of Manual Phased Array Ultrasonic Techniques for Pipe Weld Inspection in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Poirier, J.; Hayes, P.; Vicat, F. [GE Inspection Technologies (United States)

2011-07-01

Phasor XS can be used for piping weld inspection in any facilities that use EPRI procedures (example: nuclear power plant in Usa, Japan, ...). Whole pipe range is inspected with 5 probes and 6 wedges: 4 1-dimensional probe for sound wave scanning (different frequency, different apertures); 1 dual matrix probe for LW scanning; there are 3 types of wedges optimized for weld inspection. Weld is scanned in 'Raster Scan', maximum range from 35 up to 80 degrees. Probe selection is defined in the procedure according to pipe diameter, pipe thickness and type of access (single or dual side). We have to note that datasets for dual matrix probe are provided with the procedure because this kind of probe cannot be programmed inside Phasor XS

Waveguide Phased Array Antenna Analysis and Synthesis

NARCIS (Netherlands)

Visser, H.J.; Keizer, W.P.M.N.

1996-01-01

Results of two software packages for analysis and synthesis of waveguide phased array antennas are shown. The antennas consist of arrays of open-ended waveguides where irises can be placed in the waveguide apertures and multiple dielectric sheets in front of the apertures in order to accomplish a

Fabrication of Phased Array EMAT and Its Characteristics

International Nuclear Information System (INIS)

Ahn, Bong Young; Cho, Seung Hyun; Kim, Young Joo; Kim, Ki Bok

2010-01-01

EMAT has been applied in various fields for flaw detection and material characterization because it has noncontact property in wave generation and a good mode selectivity. Unfortunately, however, EMAT shows low signal to noise ratio relative to commercial contact transducer because of low energy conversion efficiency. If the phase matching through the control of time delay between each coil consisting of the array EMAT is accomplished, it is expected that it will be a solution for the improvement of low signal to noise ratio. In this experiment, the phased array EMATs which consists of 3 or 4 meander coils and one big magnet were fabricated for surface and vertical shear wave generation. Effect of phased delay control on signal directivity and amplitude enhancement was verified. A slit with the depth of 0.5 mm and a side-drill hole of 0.5 mm diameter were clearly detected by fabricated phased array EMATs, respectively

Phase-locked, high power, mid-infrared quantum cascade laser arrays

Science.gov (United States)

Zhou, W.; Slivken, S.; Razeghi, M.

2018-04-01

We demonstrate phase-locked, high power quantum cascade laser arrays, which are combined using a monolithic, tree array multimode interferometer, with emission wavelengths around 4.8 μm. A maximum output power of 15 W was achieved from an eight-element laser array, which has only a slightly higher threshold current density and a similar slope efficiency compared to a Fabry-Perot laser of the same length. Calculated multimode interferometer splitting loss is on the order of 0.27 dB for the in-phase supermode. In-phase supermode operation with nearly ideal behavior is demonstrated over the working current range of the array.

Four-to-one power combiner for 20 GHz phased array antenna using RADC MMIC phase shifters

Science.gov (United States)

1991-01-01

The design and microwave simulation of two-to-one microstrip power combiners is described. The power combiners were designed for use in a four element phase array receive antenna subarray at 20 GHz. Four test circuits are described which were designed to enable testing of the power combiner and the four element phased array antenna. Test Circuit 1 enables measurement of the two-to-one power combiner. Test Circuit 2 enables measurement of the four-to-one power combiner. Test Circuit 3 enables measurement of a four element antenna array without phase shifting MMIC's in order to characterize the power combiner with the antenna patch-to-microstrip coaxial feedthroughs. Test circuit 4 is the four element phased array antenna including the RADC MMIC phase shifters and appropriate interconnects to provide bias voltages and control phase bits.

Project inspection using mobile technology - phase II : assessing the impacts of mobile technology on project inspection.

Science.gov (United States)

2015-01-01

As mobile technology becomes widely available and affordable, transportation agencies can use this : technology to streamline operations involved within project inspection. This research, conducted in two : phases, identified opportunities for proces...

PHARUS : PHased ARray Universal SAR

NARCIS (Netherlands)

Paquay, M.H.A.; Vermeulen, B.C.B.; Koomen, P.J.; Hoogeboom, P.; Snoeij, P.; Pouwels, H.

1996-01-01

In the Netherlands, a polarimetric C-band aircraft SAR (Synthetic Aperture Radar) has been developed. The project is called PHARUS, an acronm for PHased ARray Universal SAR. This instrument serves remote sensing applications. The antenna system contains 48 active modules (expandable to 96). A module

A portable solution to enable guided ultrasonic inspection

International Nuclear Information System (INIS)

Enenkel, Laurent; Buechler, Johannes; Poirier, Jerome; Jervis David

2012-01-01

This paper describes the development and application of an innovative ultrasonic (UT) inspection system, which is 100% guided and menu-driven to reduce human error and ensure both inspection accuracy and productivity in the reliable and accurate non-destructive testing (NDT) of shafts, tubes, pipes, and other components and structures. Set-up is menu-directed with the minimum of instrument-specific training, allowing the integral operating software to calculate all the ultrasonic parameters for each task according to the inspection procedure and create an easy-to-follow inspection plan, using either phased array or conventional UT. The operator then scans the work piece, with an encoded scanner, which ensures that the inspection plan is strictly followed. Inspection data is transmitted to a review station in the industry-accepted, non-proprietary DICONDE protocol, allowing advanced analysis tools, such as real time, volume corrected imaging, to allow easier and more reliable image interpretation. By using GEs Rhythm software platform, inspection data can be reviewed and shared, reports generated and inspection results archived for traceability, tracking or further analysis.

Airborne electronically steerable phased array

Science.gov (United States)

1972-01-01

The results are presented of the second stage of a program for the design and development of a phased array capable of simultaneous and separate transmission and reception of radio frequency signals at S-band frequencies. The design goals of this stage were the development of three major areas of interest required for the final prototype model. These areas are the construction and testing of the low-weight, full-scale 128-element array of antenna elements, the development of the RF manifold feed system, and the construction and testing of a working module containing diplexer and transmit and receive circuits.

Phased Array Antenna Testbed Development at the NASA Glenn Research Center

Science.gov (United States)

Lambert, Kevin M.; Kubat, Gregory; Johnson, Sandra K.; Anzic, Godfrey

2003-01-01

Ideal phased array antennas offer advantages for communication systems, such as wide-angle scanning and multibeam operation, which can be utilized in certain NASA applications. However, physically realizable, electronically steered, phased array antennas introduce additional system performance parameters, which must be included in the evaluation of the system. The NASA Glenn Research Center (GRC) is currently conducting research to identify these parameters and to develop the tools necessary to measure them. One of these tools is a testbed where phased array antennas may be operated in an environment that simulates their use. This paper describes the development of the testbed and its use in characterizing a particular K-Band, phased array antenna.

Hydrodynamics of single- and two-phase flow in inclined rod arrays

International Nuclear Information System (INIS)

Todreas, N.E.

1984-01-01

Required inputs for thermal-hydraulic codes are constitutive relations for fluid-solid flow resistance, in single-phase flow, and interfacial momentum exchange (relative phase motion), in two-phase flow. An inclined rod array air-water experiment was constructed to study the hydrodynamics of multidimensional porous medium flow in rod arrays. Velocities, pressures, bubble distributions, and void fractions were measured in inline and rotational square rod arrays of P/d = 1.5, at 0, 30, 45, and 90 degree inclinations to the vertical flow direction. Constitutive models for single-phase flow resistance are reviewed, new comprehensive models developed, and an assessment with previously published and new data made. The principle of superimposing one-dimensional correlations proves successful for turbulent single-phase inclined flow. For bubbly two-phase yawed flow through incline rod arrays a new flow separation phenomena was observed and modeled. Bubbles of diameters significantly smaller than the rod diameter travel along the rod axis, while larger diameter bubbles move through the rod array gaps. The outcome is a flow separation not predictable with current interfacial momentum exchange models. This phenomenon was not observed in rotated square rod arrays. Current interfacial momentum exchange models were confirmed for this rod arrangement. Models for the two phase flow resistance multiplier for cross flow were reviewed and compared with data from cross and yawed flow rod arrays. Both drag and lift components of the multiplier were well predicted by the homogenous model. Other models reviewed overpredicted the data by a factor of two

Automated flaw detection scheme for cast austenitic stainless steel weld specimens using Hilbert-Huang transform of ultrasonic phased array data

International Nuclear Information System (INIS)

Khan, Tariq; Majumdar, Shantanu; Udpa, Lalita; Ramuhalli, Pradeep; Crawford, Susan; Diaz, Aaron; Anderson, Michael T.

2012-01-01

The objective of this work is to develop processing algorithms to detect and localize flaws using ultrasonic phased-array data. Data was collected on cast austenitic stainless stell (CASS) weld specimens onloan from the U.S. nuclear power industry' Pressurized Walter Reactor Owners Group (PWROG) traveling specimen set. Each specimen consists of a centrifugally cast stainless stell (CCSS) pipe section welded to a statically cst(SCSS) or wrought (WRSS) section. The paper presents a novel automated flaw detection and localization scheme using low frequency ultrasonic phased array inspection singals from the weld and heat affected zone of the based materials. The major steps of the overall scheme are preprocessing and region of interest (ROI) detection followed by the Hilbert-Huang transform (HHT) of A-scans in the detected ROIs. HHT offers time-frequency-energy distribution for each ROI. The Accumulation of energy in a particular frequency band is used as a classification feature for the particular ROI

High Rate User Ka-Band Phased Array Antenna Test Results

Science.gov (United States)

Caroglanian, Armen; Perko, Kenneth; Seufert, Steve; Dod, Tom; Warshowsky, Jay; Day, John H. (Technical Monitor)

2001-01-01

The High Rate User Phased Array Antenna (HRUPAA) is a Ka-Band planar phased array designed by the Harris Corporation for the NASA Goddard Space Flight Center. The HRUPAA permits a satellite to downlink data either to a ground station or through the Tracking and Data Relay Satellite System (TDRSS). The HRUPAA is scanned electronically by ground station / user satellite command over a 120 degree cone angle. The phased array has the advantage of not imparting attitude disturbances to the user spacecraft. The 288-element transmit-only array has distributed RF amplifiers integrated behind each of the printed patch antenna elements. The array has 33 dBW EIRP and is left-hand circularly polarized. An engineering model of a partially populated array has been developed and delivered to NASA Goddard Space Flight Center. This report deals with the testing of the engineering model at the Goddard Antenna Range near-field and compact range facilities. The antenna specifications are described first, followed by the test plan and test results.

Optically Controlled Phased Array Antenna

National Research Council Canada - National Science Library

Garafalo, David

1998-01-01

.... The antenna is a 3-foot by 9 foot phased array capable of a scan angle of 120 degrees. The antenna was designed to be conformal to the cargo door of a large aircraft and is designed to operate in the frequency range of 830 - 1400 MHz with a 30...

Hydrodynamics of single- and two-phase flow in inclined rod arrays

International Nuclear Information System (INIS)

Ebeling-Koning, D.B.; Todreas, N.E.

1983-09-01

Required inputs for thermal-hydraulic codes are constitutive relations for fluid-solid flow resistance, in single-phase flow, and interfacial momentum exchange (relative phase motion), in two-phase flow. An inclined rod array air-water experiment was constructed to study the hydrodynamics of multidimensional porous medium flow in rod arrays. Velocities, pressures, and bubble distributions were measured in square rod arrays of P/d = 1.5, at 0, 30, 45, and 90 degree inclinations to the vertical flow direction. Constitutive models for single-phase flow resistance are reviewed, new comprehensive models developed, and an assessment with previously published and new data made. The principle of superimposing one-dimensional correlations proves successful for turbulent single-phase inclined flow. For bubbly two-phase incline flow a new flow separation phenomena was observed and modeled. A two-region liquid velocity model is developed to explain the experimentally observed phenomena. Fundamental data for bubbles rising in rod arrays were also taken

Visualization and quantitative research of stress corrosion cracking using the three-dimensional phased array ultrasonic technique

International Nuclear Information System (INIS)

Kitazawa, So; Kono, Naoyuki; Kudo, Takeshi; Isaka, Katsumi

2013-01-01

The three-dimensional phased-array (3D-PA) ultrasonic technique has been applied to a stress corrosion cracking (SCC) in base metal, and its results for sizing have been quantitatively evaluated. The 3D-PA allows operators to scan objects volumetrically and to display results as 3D images facilitating evaluation processes considerably. The scanning pattern used is called the moving rotational sectorial-scan (MRS-scan) and it is composed of many sectors of different azimuth angles as moving the probe linearly. The MRS-scan significantly improves the inspection of flaws without skillful searching motion of the probe, because the flaws are stereoscopically insonified by a number of ultrasonic beams coming from various directions. The SCC was evaluated by the MRS-scan with a matrix array probe. Not only the deepest tip but also all parts of the crack were able to be successfully visualized and sized with an accuracy of the root mean square error of 0.9 mm. (author)

A phased array bread board for future remote sensing applications

Science.gov (United States)

Zahn, R. W.; Schmidt, E.

The next generation of SAR antennas will be of the active phased-array type. The ongoing development of a phased-array breadboard for remote sensing is described. Starting from a detailed system design, a functional representative breadboard was developed. The design and the performance of the breadboard are discussed.

PROSPECTS FOR THE DEVELOPMENT OF PHASED ANTENNA ARRAYS

Directory of Open Access Journals (Sweden)

A. P. Dzuba

2013-01-01

Full Text Available This article describes the main achievements in the development of phased antenna arrays (par in the past decade. Provides an overview of the most famous systems based on the PAR and PAR based on MMIC technology - PAR in radar stations, PAR to control the laser and optical beams. The existing options for the design of the PAR:ferroelectric antenna array; plasma antenna with electronic scanning; reflective grating on 100-mm semiconductor wafers; wideband antenna arrays with aperture; antenna arrays with digital beam forming.

Design and Analysis of MEMS Linear Phased Array

Directory of Open Access Journals (Sweden)

Guoxiang Fan

2016-01-01

Full Text Available A structure of micro-electro-mechanical system (MEMS linear phased array based on “multi-cell” element is designed to increase radiation sound pressure of transducer working in bending vibration mode at high frequency. In order to more accurately predict the resonant frequency of an element, the theoretical analysis of the dynamic equation of a fixed rectangular composite plate and finite element method simulation are adopted. The effects of the parameters both in the lateral and elevation direction on the three-dimensional beam directivity characteristics are comprehensively analyzed. The key parameters in the analysis include the “cell” number of element, “cell” size, “inter-cell” spacing and the number of elements, element width. The simulation results show that optimizing the linear array parameters both in the lateral and elevation direction can greatly improve the three-dimensional beam focusing for MEMS linear phased array, which is obviously different from the traditional linear array.

Radiographic inspection. Film replacement with digital detector arrays in aerospace applications

International Nuclear Information System (INIS)

Schulte, Frank; Bavendiek, Klaus

2016-01-01

The new Digital Radiographic Inspection method replace more and more the conventional Film technique. For DDA (Digital Detector Array) systems it is currently necessary to use automated or semi-automated systems. For CR (Computer Radiography) Systems the conventional Film Systems may be used. For this CR technique operators can use same X-Ray Units (Bunker) and same X-Ray equipment. But on CR technique we have basically the same settings like the Film-based technique. More or less same exposure times and for aerospace application long scanning times for the CR foils. In fact there is no big benefit in capacity or in economical view. Regarding this issue we thought about the option to use a DDA System instead of a Film or CR System to use the current Film Equipment (Bunker, Generator, Tube.) and replace this 1:1 by a manual system. In this time only small detectors with fine pixel pitch was available on the market. With this type of DDA's is was absolutely uneconomical to inspect parts in serial inspection. Therefore a new generation of DDA's were developed, which is able to replace Film or CR System 1:1 with adequate economical properties for specific applications. The new PerkinElmer XRD 1611 Panel has a size of 40 x 40 cm and a pixel pitch of 100 μm. The baseline for the new DDA Panel was the most used X-Ray Film in size 30 x 40 cm. The Pixel Pitch and requirements for Bad Pixel based on the requirements for spatial resolution of the applicable ASTM standards and different customer specifications for castings. With this new DDA System is it possible to inspect small and medium castings in very short time with excellent image quality. The System is able to process images under 1 minute include averaging. Images will be transferred by a specific software tool to an offline reading station where certified Level 2 operator can inspect the images. Images will be archived as 16bit DICONDE File. All relevant images information are included in DICONDE File

Large-Aperture Membrane Active Phased-Array Antennas

Science.gov (United States)

Karasik, Boris; McGrath, William; Leduc, Henry

2009-01-01

Large-aperture phased-array microwave antennas supported by membranes are being developed for use in spaceborne interferometric synthetic aperture radar systems. There may also be terrestrial uses for such antennas supported on stationary membranes, large balloons, and blimps. These antennas are expected to have areal mass densities of about 2 kg/sq m, satisfying a need for lightweight alternatives to conventional rigid phased-array antennas, which have typical areal mass densities between 8 and 15 kg/sq m. The differences in areal mass densities translate to substantial differences in total mass in contemplated applications involving aperture areas as large as 400 sq m. A membrane phased-array antenna includes patch antenna elements in a repeating pattern. All previously reported membrane antennas were passive antennas; this is the first active membrane antenna that includes transmitting/receiving (T/R) electronic circuits as integral parts. Other integral parts of the antenna include a network of radio-frequency (RF) feed lines (more specifically, a corporate feed network) and of bias and control lines, all in the form of flexible copper strip conductors on flexible polymeric membranes. Each unit cell of a prototype antenna (see Figure 1) contains a patch antenna element and a compact T/R module that is compatible with flexible membrane circuitry. There are two membrane layers separated by a 12.7-mm air gap. Each membrane layer is made from a commercially available flexible circuit material that, as supplied, comprises a 127-micron-thick polyimide dielectric layer clad on both sides with 17.5-micron-thick copper layers. The copper layers are patterned into RF, bias, and control conductors. The T/R module is located on the back side of the ground plane and is RF-coupled to the patch element via a slot. The T/R module is a hybrid multilayer module assembled and packaged independently and attached to the membrane array. At the time of reporting the information for

Transverse Oscillations for Phased Array Vector Velocity Imaging

DEFF Research Database (Denmark)

Pihl, Michael Johannes; Jensen, Jørgen Arendt

2010-01-01

of superficial blood vessels. To broaden the usability of the method, it should be expanded to a phased array geometry enabling vector velocity imaging of the heart. Therefore, the scan depth has to be increased to 10-15 cm. This paper presents suitable pulse echo fields (PEF). Two lines are beamformed...... (correlation coefficient, R: -0.76), and therefore predict estimator performance. CV is correlated with the standard deviation (R=0.74). The results demonstrate the potential for using a phased array for vector velocity imaging at larger depths, and potentially for imaging the heart....

Simulation of a circular phased array for a portable ultrasonic polar scan

Science.gov (United States)

Daemen, Jannes; Kersemans, Mathias; Martens, Arvid; Verboven, Erik; Delrue, Steven; Van Paepegem, Wim; Degrieck, Joris; Van Den Abeele, Koen

2018-04-01

The development of new composite materials, often anisotropic in nature, requires intricate approaches to characterize these materials and to detect internal defects. The Ultrasonic Polar Scan (UPS) is able to achieve both goals. During an UPS experiment, a material spot is insonified at several angles Ψ(θ,ϕ), after which the reflected or transmitted signal is recorded. While excellent results have been obtained using an in-house developed 5-axis scanner, UPS measurements with the current set-up are too lengthy and cumbersome for in-situ industrial application. Therefore, we propose to replace the complex mechanical steering of the transducers by a hemispherical phased array consisting of small PZT elements. This allows to create a compact and portable setup without compromising the current data quality. By successively activating a specific set of elements of the array and choosing appropriate inter-element time delays, the beam can be electronically steered from any angle to a fixed position on the targeted sample. Consequently, UPS reflection measurements can be performed at this position from a wide range of angles in a timeframe of seconds. Additionally, by using apodization windows, it is possible to efficiently reduce the intensity of unwanted side lobes and to create a phase profile which closely resembles that of a bounded plane wave, leading to an easier interpretation of the recorded data. The appropriate time delays and apodization parameters can be found though a multi-objective inverse problem in which both the phase profile and the side lobe reduction are optimized. This approach enables the creation of an effective beam profile to be used during UPS experiments for the characterization and inspection of composite materials. Our simulation approach is a crucial step towards a next-generation UPS device for industrial applications and in-field measurements.

Matrix phased array (MPA) imaging technology for resistance spot welds

Science.gov (United States)

Na, Jeong K.; Gleeson, Sean T.

2014-02-01

A three-dimensional MPA probe has been incorporated with a high speed phased array electronic board to visualize nugget images of resistance spot welds. The primary application area of this battery operated portable MPA ultrasonic imaging system is in the automotive industry which a conventional destructive testing process is commonly adopted to check the quality of resistance spot welds in auto bodies. Considering an average of five-thousand spot welds in a medium size passenger vehicle, the amount of time and effort given to popping the welds and measuring nugget size are immeasurable in addition to the millions of dollars' worth of scrap metals recycled per plant per year. This wasteful labor intensive destructive testing process has become less reliable as auto body sheet metal has transitioned from thick and heavy mild steels to thin and light high strength steels. Consequently, the necessity of developing a non-destructive inspection methodology has become inevitable. In this paper, the fundamental aspects of the current 3-D probe design, data acquisition algorithms, and weld nugget imaging process are discussed.

Matrix phased array (MPA) imaging technology for resistance spot welds

International Nuclear Information System (INIS)

Na, Jeong K.; Gleeson, Sean T.

2014-01-01

A three-dimensional MPA probe has been incorporated with a high speed phased array electronic board to visualize nugget images of resistance spot welds. The primary application area of this battery operated portable MPA ultrasonic imaging system is in the automotive industry which a conventional destructive testing process is commonly adopted to check the quality of resistance spot welds in auto bodies. Considering an average of five-thousand spot welds in a medium size passenger vehicle, the amount of time and effort given to popping the welds and measuring nugget size are immeasurable in addition to the millions of dollars' worth of scrap metals recycled per plant per year. This wasteful labor intensive destructive testing process has become less reliable as auto body sheet metal has transitioned from thick and heavy mild steels to thin and light high strength steels. Consequently, the necessity of developing a non-destructive inspection methodology has become inevitable. In this paper, the fundamental aspects of the current 3-D probe design, data acquisition algorithms, and weld nugget imaging process are discussed

Matrix phased array (MPA) imaging technology for resistance spot welds

Energy Technology Data Exchange (ETDEWEB)

Na, Jeong K.; Gleeson, Sean T. [Edison Welding Institute, 1250 Arthur E. Adams Drive, Columbus, OH 43221 (United States)

2014-02-18

A three-dimensional MPA probe has been incorporated with a high speed phased array electronic board to visualize nugget images of resistance spot welds. The primary application area of this battery operated portable MPA ultrasonic imaging system is in the automotive industry which a conventional destructive testing process is commonly adopted to check the quality of resistance spot welds in auto bodies. Considering an average of five-thousand spot welds in a medium size passenger vehicle, the amount of time and effort given to popping the welds and measuring nugget size are immeasurable in addition to the millions of dollars' worth of scrap metals recycled per plant per year. This wasteful labor intensive destructive testing process has become less reliable as auto body sheet metal has transitioned from thick and heavy mild steels to thin and light high strength steels. Consequently, the necessity of developing a non-destructive inspection methodology has become inevitable. In this paper, the fundamental aspects of the current 3-D probe design, data acquisition algorithms, and weld nugget imaging process are discussed.

Circularly Polarized Planar Helix Phased Antenna Array for 5G Mobile Terminals

DEFF Research Database (Denmark)

Syrytsin, Igor A.; Zhang, Shuai; Pedersen, Gert F.

2017-01-01

In this paper, a planar helix mobile phased antenna array is proposed for 5th generation communication systems with operating frequency of 28GHz. The proposed array displays circular polarization in the endfire direction. Over 65 degrees of axial ratio beamwidth and 7GHz of axial ratio bandwidth...... has been achieved in the proposed design. The coverage performance of the proposed phased antenna array has also been studied by using the coverage efficiency metric. Coverage efficiency of 50 % at 5 dBi gain is achieved by the proposed phased mobile antenna array....

Active cancellation of probing in linear dipole phased array

CERN Document Server

Singh, Hema; Jha, Rakesh Mohan

2015-01-01

In this book, a modified improved LMS algorithm is employed for weight adaptation of dipole array for the generation of beam pattern in multiple signal environments. In phased arrays, the generation of adapted pattern according to the signal scenario requires an efficient adaptive algorithm. The antenna array is expected to maintain sufficient gain towards each of the desired source while at the same time suppress the probing sources. This cancels the signal transmission towards each of the hostile probing sources leading to active cancellation. In the book, the performance of dipole phased array is demonstrated in terms of fast convergence, output noise power and output signal-to-interference-and noise ratio. The mutual coupling effect and role of edge elements are taken into account. It is established that dipole array along with an efficient algorithm is able to maintain multilobe beamforming with accurate and deep nulls towards each probing source. This work has application to the active radar cross secti...

Sampling phased array a new technique for signal processing and ultrasonic imaging

OpenAIRE

Bulavinov, A.; Joneit, D.; Kröning, M.; Bernus, L.; Dalichow, M.H.; Reddy, K.M.

2006-01-01

Different signal processing and image reconstruction techniques are applied in ultrasonic non-destructive material evaluation. In recent years, rapid development in the fields of microelectronics and computer engineering lead to wide application of phased array systems. A new phased array technique, called "Sampling Phased Array" has been developed in Fraunhofer Institute for non-destructive testing. It realizes unique approach of measurement and processing of ultrasonic signals. The sampling...

The investigation of the phase-locking stability in linear arrays of Josephson junctions and arrays closed into a superconducting loop

International Nuclear Information System (INIS)

Darula, M.; Seidel, P.; Misanik, B.; Busse, F.; Heinz, E.; Benacka, S.

1994-01-01

The phase-locking stability is investigated theoretically in two structures: linear arrays of Josephson junctions shunted by resistive load and arrays closed into superconducting loop. In both cases the quasi-identical junctions are supposed to be in arrays. The stability as a function of spread in Josephson junction parameters as well as a function of other circuit parameters is investigated. Using Floquet theory it is shown that spread in critical currents of Josephson junction limit the stability of phase-locking state. From the simulations it follows that the phase-locking in arrays closed into superconducting loop is more stable against the spread in junction parameters than in the case of linear array of Josephson junctions. (orig.)

Phased Array Focusing for Acoustic Wireless Power Transfer.

Science.gov (United States)

Tseng, Victor Farm-Guoo; Bedair, Sarah S; Lazarus, Nathan

2018-01-01

Wireless power transfer (WPT) through acoustic waves can achieve higher efficiencies than inductive coupling when the distance is above several times the transducer size. This paper demonstrates the use of ultrasonic phased arrays to focus power to receivers at arbitrary locations to increase the power transfer efficiency. Using a phased array consisting of 37 elements at a distance nearly 5 times the receiver transducer diameter, a factor of 2.6 increase in efficiency was achieved when compared to a case equivalent to a single large transducer with the same peak efficiency distance. The array has a total diameter of 7 cm, and transmits through air at 40 kHz to a 1.1-cm diameter receiver, achieving a peak overall efficiency of 4% at a distance of 5 cm. By adjusting the focal distance, the efficiency can also be maintained relatively constant at distances up to 9 cm. Numerical models were developed and shown to closely match the experimental energy transfer behavior; modeling results indicate that the efficiency can be further doubled by increasing the number of elements. For comparison, an inductive WPT system was also built with the diameters of the transmitting and receiving coils equivalent to the dimensions of the transmitting ultrasonic phased array and receiver transducer, and the acoustic WPT system achieved higher efficiencies than the inductive WPT system when the transmit-to-receive distance is above 5 cm. In addition, beam angle steering was demonstrated by using a simplified seven-element 1-D array, achieving power transfer less dependent on receiver placement.

Optimization of ultrasonic array inspections using an efficient hybrid model and real crack shapes

Energy Technology Data Exchange (ETDEWEB)

Felice, Maria V., E-mail: maria.felice@bristol.ac.uk [Department of Mechanical Engineering, University of Bristol, Bristol, U.K. and NDE Laboratory, Rolls-Royce plc., Bristol (United Kingdom); Velichko, Alexander, E-mail: p.wilcox@bristol.ac.uk; Wilcox, Paul D., E-mail: p.wilcox@bristol.ac.uk [Department of Mechanical Engineering, University of Bristol, Bristol (United Kingdom); Barden, Tim; Dunhill, Tony [NDE Laboratory, Rolls-Royce plc., Bristol (United Kingdom)

2015-03-31

Models which simulate the interaction of ultrasound with cracks can be used to optimize ultrasonic array inspections, but this approach can be time-consuming. To overcome this issue an efficient hybrid model is implemented which includes a finite element method that requires only a single layer of elements around the crack shape. Scattering Matrices are used to capture the scattering behavior of the individual cracks and a discussion on the angular degrees of freedom of elastodynamic scatterers is included. Real crack shapes are obtained from X-ray Computed Tomography images of cracked parts and these shapes are inputted into the hybrid model. The effect of using real crack shapes instead of straight notch shapes is demonstrated. An array optimization methodology which incorporates the hybrid model, an approximate single-scattering relative noise model and the real crack shapes is then described.

Research on calibration error of carrier phase against antenna arraying

Science.gov (United States)

Sun, Ke; Hou, Xiaomin

2016-11-01

It is the technical difficulty of uplink antenna arraying that signals from various quarters can not be automatically aligned at the target in deep space. The size of the far-field power combining gain is directly determined by the accuracy of carrier phase calibration. It is necessary to analyze the entire arraying system in order to improve the accuracy of the phase calibration. This paper analyzes the factors affecting the calibration error of carrier phase of uplink antenna arraying system including the error of phase measurement and equipment, the error of the uplink channel phase shift, the position error of ground antenna, calibration receiver and target spacecraft, the error of the atmospheric turbulence disturbance. Discuss the spatial and temporal autocorrelation model of atmospheric disturbances. Each antenna of the uplink antenna arraying is no common reference signal for continuous calibration. So it must be a system of the periodic calibration. Calibration is refered to communication of one or more spacecrafts in a certain period. Because the deep space targets are not automatically aligned to multiplexing received signal. Therefore the aligned signal should be done in advance on the ground. Data is shown that the error can be controlled within the range of demand by the use of existing technology to meet the accuracy of carrier phase calibration. The total error can be controlled within a reasonable range.

Inspection of bottom and lid welds for disposal canisters

International Nuclear Information System (INIS)

Pitkaenen, J.

2010-09-01

This report presents the inspection techniques of copper electron beam and friction stir welds. Both welding methods are described briefly and a more detailed description of the defects occurring in each welding methods is given. The defect types form a basis for the design of non-destructive testing. The inspection of copper material is challenging due to the anisotropic properties of the weld and local changes in the grain size of the base material. Four different methods are used for inspection. Ultrasonic and radiographic testing techniques are used for inspection of volume. Eddy current and visual testing techniques are used for inspection of the surface and near surface area. All these methods have some limitations which are related to the physics of the used method. All inspection methods need to be carried out remotely because of the radiation from the spent nuclear fuel. All methods have been described in detail and the use of the chosen inspection techniques has been justified. Phased array technology has been applied in ultrasonic testing. Ultrasonic phased array technology enables the electrical modification of the sound field during inspection so that the sound field can be adjusted dynamically for different situations and detection of different defect types. The frequency of the phased array probe has been chosen to be 3.5 MHz. It is a compromise between good sizing and defect detectability. It must be taken into account that ultrasonic testing is not suitable for detection of defect types which are in the direction of the beam. Ultrasonic and radiographic testing techniques complement each other in case of planar defects. Positioning of the indication in the radial direction is rather limited in radiographic testing. Surface inspection has been added to the inspection routine because indications from the outer surface of the canister cannot be distinguished from weld defects in the radiographic image. A 9 MeV linear accelerator has been used in the

Mutual-Coupling Based Phased-Array Calibration: A Robust and Versatile Approach

NARCIS (Netherlands)

Bekers, D.J.; Dijk, R. van; Vliet, F.E. van

2013-01-01

The transmit and receive modules of a large phased array are often calibrated for amplitude and phase variations by an internal calibration network and an offline characterization of the complete array in an anechoic chamber. Such a solution is less obvious in view of current trends towards

Ku Band Phased Array Feed Development for Surface Water Ocean Topography Mission

Data.gov (United States)

National Aeronautics and Space Administration — The purpose of this project is to design components essential to the development of phased arrays and phased array feeds for use in remote sensing. Specifically the...

Bond quality control of aluminium stabilised superconductors with ultrasonic phased-array technology

International Nuclear Information System (INIS)

Neuenschwander, J.; Luethi, T.; Horvath, I.L.

2001-01-01

Novel aluminium stabilised superconductors are currently being produced for the Large Hadron Collider detectors ATLAS and CMS. For a satisfying service of the conductor an intact bonding between the different constituents must be guaranteed. We have shown previously that ultrasonics is a powerful tool for checking the bond quality. However, up to now the full width of the bond could be inspected only on short samples with a mechanical scanner. The essence of this presentation is the introduction of the phased-array technique which allows a continuous analysis of the complete bond over km-long conductor units during their manufacture. For now, more than 50 km of conductor have been tested during co-extrusion. Disbondings are detected as regions with enhanced echo-amplitudes. We are about to set-up a second system for the control of an electron beam welding process which is used for the reinforcement of the CMS conductor. (orig.)

Contribution to the development and the modelling of an ultrasonic conformable phased array transducer for the contact inspection of 3D complex geometry components

International Nuclear Information System (INIS)

Guedes, O.

2005-04-01

With the difficulties encountered for the exploration of complex shape surfaces, particularly in nuclear industry, the ultrasonic conformable phased array transducer allows a non destructive evaluation of parts with 3D complex parts. For this, one can use the Smart Contact Transducer principle to generate an ultrasonic field by adaptive dynamic focalisation, with a matrix array composed of independent elements moulded in a soft resin. This work deals with the electro-acoustic conception, with the realization of such a prototype and with the study of it's mechanical and acoustic behaviour. The array design is defined using a radiation model adapted to the simulation of contact sources on a free surface. Once one have defined the shape of the radiating elements, a vibratory analysis using finite elements method allows the determination of the emitting structure with 1-3 piezocomposite, witch leads to the realization of emitting-receiving elements. With the measurement of the field transmitted by such elements, we deduced new hypothesis to change the model of radiation. Thus one can take into account normal and tangential stresses calculated with finite element modelling at the interface between the element and the propagation medium, to use it with the semi-analytical model. Some vibratory phenomena dealing with fluid coupling of contact transducers have been studied, and the prediction of the transverse wave radiation profile have been improved. The last part of this work deals with the realization of the first prototype of the conformable phased array transducer. For this a deformation measuring system have been developed, to determine the position of each element on real time with the displacement of the transducer on complex shape surfaces. With those positions, one can perform the calculation of the a delay law intended for the adaptive dynamic focusing of the desired ultrasonic field. The conformable phased array transducer have been characterized in

Removing Background Noise with Phased Array Signal Processing

Science.gov (United States)

Podboy, Gary; Stephens, David

2015-01-01

Preliminary results are presented from a test conducted to determine how well microphone phased array processing software could pull an acoustic signal out of background noise. The array consisted of 24 microphones in an aerodynamic fairing designed to be mounted in-flow. The processing was conducted using Functional Beam forming software developed by Optinav combined with cross spectral matrix subtraction. The test was conducted in the free-jet of the Nozzle Acoustic Test Rig at NASA GRC. The background noise was produced by the interaction of the free-jet flow with the solid surfaces in the flow. The acoustic signals were produced by acoustic drivers. The results show that the phased array processing was able to pull the acoustic signal out of the background noise provided the signal was no more than 20 dB below the background noise level measured using a conventional single microphone equipped with an aerodynamic forebody.

Wavefront sensing and adaptive control in phased array of fiber collimators

Science.gov (United States)

Lachinova, Svetlana L.; Vorontsov, Mikhail A.

2011-03-01

A new wavefront control approach for mitigation of atmospheric turbulence-induced wavefront phase aberrations in coherent fiber-array-based laser beam projection systems is introduced and analyzed. This approach is based on integration of wavefront sensing capabilities directly into the fiber-array transmitter aperture. In the coherent fiber array considered, we assume that each fiber collimator (subaperture) of the array is capable of precompensation of local (onsubaperture) wavefront phase tip and tilt aberrations using controllable rapid displacement of the tip of the delivery fiber at the collimating lens focal plane. In the technique proposed, this tip and tilt phase aberration control is based on maximization of the optical power received through the same fiber collimator using the stochastic parallel gradient descent (SPGD) technique. The coordinates of the fiber tip after the local tip and tilt aberrations are mitigated correspond to the coordinates of the focal-spot centroid of the optical wave backscattered off the target. Similar to a conventional Shack-Hartmann wavefront sensor, phase function over the entire fiber-array aperture can then be retrieved using the coordinates obtained. The piston phases that are required for coherent combining (phase locking) of the outgoing beams at the target plane can be further calculated from the reconstructed wavefront phase. Results of analysis and numerical simulations are presented. Performance of adaptive precompensation of phase aberrations in this laser beam projection system type is compared for various system configurations characterized by the number of fiber collimators and atmospheric turbulence conditions. The wavefront control concept presented can be effectively applied for long-range laser beam projection scenarios for which the time delay related with the double-pass laser beam propagation to the target and back is compared or even exceeds the characteristic time of the atmospheric turbulence change

An Instrument for Inspecting Aspheric Optical Surfaces and Components, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This is a Phase I proposal to develop an extremely versatile optical inspection tool for determining the optical figure of aspheric optical components, such as test...

Wake Vortex Detection: Phased Microphone vs. Linear Infrasonic Array

Science.gov (United States)

Shams, Qamar A.; Zuckerwar, Allan J.; Sullivan, Nicholas T.; Knight, Howard K.

2014-01-01

Sensor technologies can make a significant impact on the detection of aircraft-generated vortices in an air space of interest, typically in the approach or departure corridor. Current state-of-the art sensor technologies do not provide three-dimensional measurements needed for an operational system or even for wake vortex modeling to advance the understanding of vortex behavior. Most wake vortex sensor systems used today have been developed only for research applications and lack the reliability needed for continuous operation. The main challenges for the development of an operational sensor system are reliability, all-weather operation, and spatial coverage. Such a sensor has been sought for a period of last forty years. Acoustic sensors were first proposed and tested by National Oceanic and Atmospheric Administration (NOAA) early in 1970s for tracking wake vortices but these acoustic sensors suffered from high levels of ambient noise. Over a period of the last fifteen years, there has been renewed interest in studying noise generated by aircraft wake vortices, both numerically and experimentally. The German Aerospace Center (DLR) was the first to propose the application of a phased microphone array for the investigation of the noise sources of wake vortices. The concept was first demonstrated at Berlins Airport Schoenefeld in 2000. A second test was conducted in Tarbes, France, in 2002, where phased microphone arrays were applied to study the wake vortex noise of an Airbus 340. Similarly, microphone phased arrays and other opto-acoustic microphones were evaluated in a field test at the Denver International Airport in 2003. For the Tarbes and Denver tests, the wake trajectories of phased microphone arrays and lidar were compared as these were installed side by side. Due to a built-in pressure equalization vent these microphones were not suitable for capturing acoustic noise below 20 Hz. Our group at NASA Langley Research Center developed and installed an

K-Band Phased Array Developed for Low- Earth-Orbit Satellite Communications

Science.gov (United States)

Anzic, Godfrey

1999-01-01

Future rapid deployment of low- and medium-Earth-orbit satellite constellations that will offer various narrow- to wide-band wireless communications services will require phased-array antennas that feature wide-angle and superagile electronic steering of one or more antenna beams. Antennas, which employ monolithic microwave integrated circuits (MMIC), are perfectly suited for this application. Under a cooperative agreement, an MMIC-based, K-band phased-array antenna is being developed with 50/50 cost sharing by the NASA Lewis Research Center and Raytheon Systems Company. The transmitting array, which will operate at 19 gigahertz (GHz), is a state-of-the-art design that features dual, independent, electronically steerable beam operation ( 42 ), a stand-alone thermal management, and a high-density tile architecture. This array can transmit 622 megabits per second (Mbps) in each beam from Earth orbit to small Earth terminals. The weight of the total array package is expected to be less than 8 lb. The tile integration technology (flip chip MMIC tile) chosen for this project represents a major advancement in phased-array engineering and holds much promise for reducing manufacturing costs.

Active phase correction of high resolution silicon photonic arrayed waveguide gratings.

Science.gov (United States)

Gehl, M; Trotter, D; Starbuck, A; Pomerene, A; Lentine, A L; DeRose, C

2017-03-20

Arrayed waveguide gratings provide flexible spectral filtering functionality for integrated photonic applications. Achieving narrow channel spacing requires long optical path lengths which can greatly increase the footprint of devices. High index contrast waveguides, such as those fabricated in silicon-on-insulator wafers, allow tight waveguide bends which can be used to create much more compact designs. Both the long optical path lengths and the high index contrast contribute to significant optical phase error as light propagates through the device. Therefore, silicon photonic arrayed waveguide gratings require active or passive phase correction following fabrication. Here we present the design and fabrication of compact silicon photonic arrayed waveguide gratings with channel spacings of 50, 10 and 1 GHz. The largest device, with 11 channels of 1 GHz spacing, has a footprint of only 1.1 cm2. Using integrated thermo-optic phase shifters, the phase error is actively corrected. We present two methods of phase error correction and demonstrate state-of-the-art cross-talk performance for high index contrast arrayed waveguide gratings. As a demonstration of possible applications, we perform RF channelization with 1 GHz resolution. Additionally, we generate unique spectral filters by applying non-zero phase offsets calculated by the Gerchberg Saxton algorithm.

A two-phase inspection model for a single component system with three-stage degradation

International Nuclear Information System (INIS)

Wang, Huiying; Wang, Wenbin; Peng, Rui

2017-01-01

This paper presents a two-phase inspection schedule and an age-based replacement policy for a single plant item contingent on a three-stage degradation process. The two phase inspection schedule can be observed in practice. The three stages are defined as the normal working stage, low-grade defective stage and critical defective stage. When an inspection detects that an item is in the low-grade defective stage, we may delay the preventive replacement action if the time to the age-based replacement is less than or equal to a threshold level. However, if it is above this threshold level, the item will be replaced immediately. If the item is found in the critical defective stage, it is replaced immediately. A hybrid bee colony algorithm is developed to find the optimal solution for the proposed model which has multiple decision variables. A numerical example is conducted to show the efficiency of this algorithm, and simulations are conducted to verify the correctness of the model. - Highlights: • A two-phase inspection model is studied. • The failure process has three stages. • The delayed replacement is considered.

Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas

Science.gov (United States)

Paal, Leslie; Mukai, Ryan; Vilntrotter, Victor; Cornish, Timothy; Lee, Dennis

2009-01-01

A method of estimating phase drifts of microwave signals distributed to, and transmitted by, antennas in an array involves the use of the signals themselves as phase references. The method was conceived as part of the solution of the problem of maintaining precise phase calibration required for proper operation of an array of Deep Space Network (DSN) antennas on Earth used for communicating with distant spacecraft at frequencies between 7 and 8 GHz. The method could also be applied to purely terrestrial phased-array radar and other radio antenna array systems. In the DSN application, the electrical lengths (effective signal-propagation path lengths) of the various branches of the system for distributing the transmitted signals to the antennas are not precisely known, and they vary with time. The variations are attributable mostly to thermal expansion and contraction of fiber-optic and electrical signal cables and to a variety of causes associated with aging of signal-handling components. The variations are large enough to introduce large phase drifts at the signal frequency. It is necessary to measure and correct for these phase drifts in order to maintain phase calibration of the antennas. A prior method of measuring phase drifts involves the use of reference-frequency signals separate from the transmitted signals. A major impediment to accurate measurement of phase drifts over time by the prior method is the fact that although DSN reference-frequency sources separate from the transmitting signal sources are stable and accurate enough for most DSN purposes, they are not stable enough for use in maintaining phase calibrations, as required, to within a few degrees over times as long as days or possibly even weeks. By eliminating reliance on the reference-frequency subsystem, the present method overcomes this impediment. In a DSN array to which the present method applies (see figure), the microwave signals to be transmitted are generated by exciters in a signal

A design concept for an MMIC (Monolithic Microwave Integrated Circuit) microstrip phased array

Science.gov (United States)

Lee, Richard Q.; Smetana, Jerry; Acosta, Roberto

1987-01-01

A conceptual design for a microstrip phased array with monolithic microwave integrated circuit (MMIC) amplitude and phase controls is described. The MMIC devices used are 20 GHz variable power amplifiers and variable phase shifters recently developed by NASA contractors for applications in future Ka proposed design, which concept is for a general NxN element array of rectangular lattice geometry. Subarray excitation is incorporated in the MMIC phased array design to reduce the complexity of the beam forming network and the number of MMIC components required.

Microelectromechanical Switches for Phased Array Antennas

Science.gov (United States)

Ponchak, George E.; Simons, Rainee N.; Scardelletti, Maximillian; Varaljay, Nicholas C.

2000-01-01

Preliminary results are presented on the fabrication and testing of a MicroElectro-Mechanical (MEM) microstrip series switch. This switch is being developed for use in a K-band phased array antenna that NASA will use for communication links in its Earth orbiting satellites. Preliminary insertion loss and isolation measurements are presented.

MEMS based monolithic Phased array using 3-bit Switched-line Phase Shifter

Directory of Open Access Journals (Sweden)

A. Karmakr

2017-10-01

Full Text Available This article details the design of an electronically scanning phased array antenna with proposed fabrication process steps. Structure is based upon RF micro-electromechanical system (MEMS technology. Capacitive type shunt switches have been implemented here to cater high frequency operation. The architecture, which is deigned at 30 GHz, consists of 3-bit (11.25º, 22.5º and 45º integrated Switched-line phase shifter and a linearly polarized microstrip patch antenna. Detailed design tricks of the Ka-band phase shifter is outlined here. The whole design is targeted for future monolithic integration. So, the substrate of choice is High Resistive Silicon (ρ > 8kΩ-cm, tan δ =0.01 and ϵr =11.8. The overall circuit occupies an cross-sectional area of 20 × 5 mm2. The simulated results show that the phase shifter can provide nearly 11.25º/22.5º/45º phase shifts and their combinations at the expense of 1dB average insertion loss at 30 GHz for eight combinations. Practical fabrication process flow using surface micromachining is proposed here. Critical dimensions of the phased array structure is governed by the deign rules of the standard CMOS/MEMS foundry.

Image-Guided Surgery of Primary Breast Cancer Using Ultrasound Phased Arrays

National Research Council Canada - National Science Library

Ebbini, Emad S

2004-01-01

.... Piezocomposite transducer technology, especially for phased arrays, is providing high-quality HIFU applicators with increased bandwidth and reduced parasitic cross coupling between the array elements...

Adaptive ground implemented phase array

Science.gov (United States)

Spearing, R. E.

1973-01-01

The simulation of an adaptive ground implemented phased array of five antenna elements is reported for a very high frequency system design that is tolerant to the radio frequency interference environment encountered by a tracking data relay satellite. Signals originating from satellites are received by the VHF ring array and both horizontal and vertical polarizations from each of the five elements are multiplexed and transmitted down to ground station. A panel on the transmitting end of the simulation chamber contains up to 10 S-band RFI sources along with the desired signal to simulate the dynamic relationship between user and TDRS. The 10 input channels are summed, and desired and interference signals are separated and corrected until the resultant sum signal-to-interference ratio is maximized. Testing performed with this simulation equipment demonstrates good correlation between predicted and actual results.

Multilevel photonic modules for millimeter-wave phased-array antennas

Science.gov (United States)

Paolella, Arthur C.; Bauerle, Athena; Joshi, Abhay M.; Wright, James G.; Coryell, Louis A.

2000-09-01

Millimeter wave phased array systems have antenna element sizes and spacings similar to MMIC chip dimensions by virtue of the operating wavelength. Designing modules in traditional planar packaing techniques are therefore difficult to implement. An advantageous way to maintain a small module footprint compatible with Ka-Band and high frequency systems is to take advantage of two leading edge technologies, opto- electronic integrated circuits (OEICs) and multilevel packaging technology. Under a Phase II SBIR these technologies are combined to form photonic modules for optically controlled millimeter wave phased array antennas. The proposed module, consisting of an OEIC integrated with a planar antenna array will operate on the 40GHz region. The OEIC consists of an InP based dual-depletion PIN photodetector and distributed amplifier. The multi-level module will be fabricated using an enhanced circuit processing thick film process. Since the modules are batch fabricated using an enhanced circuit processing thick film process. Since the modules are batch fabricated, using standard commercial processes, it has the potential to be low cost while maintaining high performance, impacting both military and commercial communications systems.

Recent development for inservice inspection of reactor pressure vessels

International Nuclear Information System (INIS)

Fischer, K.; Engl, G.; Rathgeb, W.; Heumueller, R.

1991-01-01

The German Nuclear Code (KTA-rules) requires a full scope inservice inspection (ISI) of reactor pressure vessels within a period of four years. This has a remarkable influence on plant operation and economy. Therefore, the development of advanced inspection equipment and techniques is directed not only to the enhancement of defect detectability and flaw sizing capabilities but also to reducing inspection times. A new manipulator system for PWR vessels together with fast data processing reduces the time for ISI of modern RPVs to 7 days. A new multichannel UT-system based on ALOK principle offers increased ultrasonic information with comfortable and rapid evaluation and presentation of results together with enhanced sizing capabilities. For specific inspection problems characterized by geometrical complexity the application of phased array probes in connection with UT-tomography provides improved ultrasonic information together with a streamlined manipulator principle and simplification of set up and tear down at the component which results in considerable reduction of radiation exposure. (orig.)

Substrate Integrated Waveguide Based Phase Shifter and Phased Array in a Ferrite Low Temperature Co-fired Ceramic Package

KAUST Repository

Nafe, Ahmed A.

2014-03-01

Phased array antennas, capable of controlling the direction of their radiated beam, are demanded by many conventional as well as modern systems. Applications such as automotive collision avoidance radar, inter-satellite communication links and future man-portable satellite communication on move services require reconfigurable beam systems with stress on mobility and cost effectiveness. Microwave phase shifters are key components of phased antenna arrays. A phase shifter is a device that controls the phase of the signal passing through it. Among the technologies used to realize this device, traditional ferrite waveguide phase shifters offer the best performance. However, they are bulky and difficult to integrate with other system components. Recently, ferrite material has been introduced in Low Temperature Co-fired Ceramic (LTCC) multilayer packaging technology. This enables the integration of ferrite based components with other microwave circuitry in a compact, light-weight and mass producible package. Additionally, the recent concept of Substrate Integrated Waveguide (SIW) allowed realization of synthesized rectangular waveguide-like structures in planar and multilayer substrates. These SIW structures have been shown to maintain the merits of conventional rectangular waveguides such as low loss and high power handling capabilities while being planar and easily integrable with other components. Implementing SIW structures inside a multilayer ferrite LTCC package enables monolithic integration of phase shifters and phased arrays representing a true System on Package (SoP) solution. It is the objective of this thesis to pursue realizing efficient integrated phase shifters and phased arrays combining the above mentioned technologies, namely Ferrite LTCC and SIW. In this work, a novel SIW phase shifter in ferrite LTCC package is designed, fabricated and tested. The device is able to operate reciprocally as well as non-reciprocally. Demonstrating a measured maximum

Depscor-95 Agile Optical Phased Arrays for Microspacecraft

National Research Council Canada - National Science Library

Fork, Richard

1999-01-01

... average power beams with little or no mechanical movement are especially interesting. Recent advances in semiconductor and optical fiber lasers suggest lightweight compact optical phased arrays suitable for microspacecraft are feasible...

Investigation of the use of uniaxial comb-shaped Galfenol patches for a guided wave-based magnetostrictive phased array sensor

Science.gov (United States)

Yoo, Byungseok; Pines, Darryll J.

2018-05-01

This paper investigates the use of uniaxial comb-shaped Fe-Ga alloy (Galfenol) patches in the development of a Magnetostrictive Phased Array Sensor (MPAS) for the Guided Wave (GW) damage inspection technique. The MPAS consists of six highly-textured Galfenol patches with a preferred orientation and a Hexagonal Magnetic Circuit Device (HMCD). The Galfenol patches individually aligned to distinct azimuthal directions were permanently attached to a thin aluminum plate specimen. The detachable HMCD encloses a biasing magnet and six sensing coils with unique directional sensing preferences, equivalent to the specific orientation of the discrete Galfenol patches. The preliminary experimental tests validated that the GW sensing performance and directional sensitivity of the Galfenol-based sensor were significantly improved by the magnetic shape anisotropy effect on the fabrication of uniaxial comb fingers to a Galfenol disc patch. We employed a series of uniaxial comb-shaped Galfenol patches to form an MPAS with a hexagonal sensor configuration, uniformly arranged within a diameter of 1". The Galfenol MPAS was utilized to identify structural damage simulated by loosening joint bolts used to fasten the plate specimen to a frame structure. We compared the damage detection results of the MPAS with those of a PZT Phased Array Sensor (PPAS) collocated to the back surface of the plate. The directional filtering characteristic of the Galfenol MPAS led to acquiring less complicated GW signals than the PPAS using omnidirectional PZT discs. However, due to the detection limit of the standard hexagonal patterned array, the two array sensors apparently identified only the loosened bolts located along one of the preferred orientations of the array configuration. The use of the fixed number of the Galfenol patches for the MPAS construction constrained the capability of sensing point multiplication of the HMCD by altering its rotational orientation, resulting in such damage detection

An automatic evaluation method for the surface profile of a microlens array using an optical interferometric microscope

International Nuclear Information System (INIS)

Lin, Chern-Sheng; Loh, Guo-Hao; Fu, Shu-Hsien; Chang, Hsun-Kai; Yang, Shih-Wei; Yeh, Mau-Shiun

2010-01-01

In this paper, an automatic evaluation method for the surface profile of a microlens array using an optical interferometric microscope is presented. For inspecting the microlens array, an XY-table is used to position it. With a He–Ne laser beam and optical fiber as a probing light, the measured image is sent to the computer to analyze the surface profile. By binary image slicing and area recognition, this study located the center of each ring and determined the substrate of the microlens array image through the background of the entire microlens array interference image. The maximum and minimum values of every segment brightness curve were determined corresponding to the change in the segment phase angle from 0° to 180°. According to the ratio of the actual ring area and the ideal ring area, the area ratio method was adopted to find the phase-angle variation of the interference ring. Based on the ratio of actual ring brightness and the ideal ring brightness, the brightness ratio method was used to determine the phase-angle variation of the interference ring fringe. The area ratio method and brightness ratio method are interchangeable in precisely determining the phase angles of the innermost and outermost rings of the interference fringe and obtaining different microlens surface altitudes of respective pixels in the segment, to greatly increase the microlens array surface profile inspection accuracy and quality

Spectrally resolved modal characteristics of leaky-wave-coupled quantum cascade phase-locked laser arrays

Science.gov (United States)

Sigler, Chris; Gibson, Ricky; Boyle, Colin; Kirch, Jeremy D.; Lindberg, Donald; Earles, Thomas; Botez, Dan; Mawst, Luke J.; Bedford, Robert

2018-01-01

The modal characteristics of nonresonant five-element phase-locked arrays of 4.7-μm emitting quantum cascade lasers (QCLs) have been studied using spectrally resolved near- and far-field measurements and correlated with results of device simulation. Devices are fabricated by a two-step metal-organic chemical vapor deposition process and operate predominantly in an in-phase array mode near threshold, although become multimode at higher drive levels. The wide spectral bandwidth of the QCL's core region is found to be a factor in promoting multispatial-mode operation at high drive levels above threshold. An optimized resonant-array design is identified to allow sole in-phase array-mode operation to high drive levels above threshold, and indicates that for phase-locked laser arrays full spatial coherence to high output powers does not require full temporal coherence.

Restoring Low Sidelobe Antenna Patterns with Failed Elements in a Phased Array Antenna

Science.gov (United States)

2016-02-01

optimum low sidelobes are demonstrated in several examples. Index Terms — Array signal processing, beams, linear algebra , phased arrays, shaped...beam antennas. I. INTRODUCTION For many phased array antenna applications , low spatial sidelobes are required, and it is desirable to maintain...represented by a linear combination of low sidelobe beamformers with no failed elements, ’s, in a neighborhood around under the constraint that the linear

Development of the advanced phased array UT technique for accurate sizing of cracks in the nozzle welding

International Nuclear Information System (INIS)

Nishida, Jun-ichiro; Kawanami, Seiichi; Ideo, Mitsushi; Matsuura, Takayuki; Chigusa, Naoki; Hirano, Shinro; Sera, Takehiko

2010-01-01

Recently, preventive maintenance tasks for welding of safe-end nozzles of reactor vessels and steam generators of PWRs in Japan had been carried out sequentially. Before the maintenance tasks, inspection services were carried out and several crack indications were found by eddy current testing (ECT). These indications were found in the welding which made by 600 series nickel base alloy and evaluated as stress corrosion cracks which were oriented to the axial direction of the nozzle. Then investigations to evaluate the depth of cracks were carried out by ultrasonic testing (UT) from inner surface of the nozzles. However they were difficult to evaluate the depth of cracks due to the high attenuation of the ultrasonic propagation caused by large grain structure of welding. And also it was required high resolution near surface region for accurate sizing. Therefore development of advanced phased array UT techniques specialized for the sizing at this portion was carried out. This paper reports the development status and verification test results. Firstly simulations of the ultrasonic propagation in the welding were carried out to optimize beam profiles of phased array probes. Next prototype probes were manufactured and verification tests were conducted to evaluate the accuracy of depth sizing. It is shown that the developed techniques have high sizing accuracy for artificial stress corrosion cracks in the welding. (author)

Linear-array systems for aerospace NDE

International Nuclear Information System (INIS)

Smith, Robert A.; Willsher, Stephen J.; Bending, Jamie M.

1999-01-01

Rapid large-area inspection of composite structures for impact damage and multi-layered aluminum skins for corrosion has been a recognized priority for several years in both military and civil aerospace applications. Approaches to this requirement have followed two clearly different routes: the development of novel large-area inspection systems, and the enhancement of current ultrasonic or eddy-current methods to reduce inspection times. Ultrasonic inspection is possible with standard flaw detection equipment but the addition of a linear ultrasonic array could reduce inspection times considerably. In order to investigate their potential, 9-element and 17-element linear ultrasonic arrays for composites, and 64-element arrays for aluminum skins, have been developed to DERA specifications for use with the ANDSCAN area scanning system. A 5 m 2 composite wing surface has been scanned with a scan resolution of approximately 3 mm in 6 hours. With subsequent software and hardware improvements all four composite wing surfaces (top/bottom, left/right) of a military fighter aircraft can potentially be inspected in less than a day. Array technology has been very widely used in the medical ultrasound field although rarely above 10 MHz, whereas lap-joint inspection requires a pulse center-frequency of 12 to 20 MHz in order to resolve the separate interfaces in the lap joint. A 128 mm-long multi-element array of 5 mmx2 mm ultrasonic elements for use with the ANDSCAN scanning software was produced to a DERA specification by an NDT manufacturer with experience in the medical imaging field. This paper analyses the performance of the transducers that have been produced and evaluates their use in scanning systems of different configurations

Wideband Low Side Lobe Aperture Coupled Patch Phased Array Antennas

Science.gov (United States)

Poduval, Dhruva

Low profile printed antenna arrays with wide bandwidth, high gain, and low Side Lobe Level (SLL) are in great demand for current and future commercial and military communication systems and radar. Aperture coupled patch antennas have been proposed to obtain wide impedance bandwidths in the past. Aperture coupling is preferred particularly for phased arrays because of their advantage of integration to other active devices and circuits, e.g. phase shifters, power amplifiers, low noise amplifiers, mixers etc. However, when designing such arrays, the interplay between array performance characteristics, such as gain, side lobe level, back lobe level, mutual coupling etc. must be understood and optimized under multiple design constraints, e.g. substrate material properties and thicknesses, element to element spacing, and feed lines and their orientation and arrangements with respect to the antenna elements. The focus of this thesis is to investigate, design, and develop an aperture coupled patch array with wide operating bandwidth (30%), high gain (17.5 dBi), low side lobe level (20 dB), and high Forward to Backward (F/B) ratio (21.8 dB). The target frequency range is 2.4 to 3 GHz given its wide application in WLAN, LTE (Long Term Evolution) and other communication systems. Notwithstanding that the design concept can very well be adapted at other frequencies. Specifically, a 16 element, 4 by 4 planar microstrip patch array is designed using HFSS and experimentally developed and tested. Starting from mutual coupling minimization a corporate feeding scheme is designed to achieve the needed performance. To reduce the SLL the corporate feeding network is redesigned to obtain a specific amplitude taper. Studies are conducted to determine the optimum location for a metallic reflector under the feed line to improve the F/B. An experimental prototype of the antenna was built and tested validating and demonstrating the performance levels expected from simulation predictions

Qualification of final closure for disposal container II - applicability of TOFD and phased array technique for overpack welding

International Nuclear Information System (INIS)

Asano, H.; Kawahara, K.; Arakawa, T.; Kurokawa, M.

2002-01-01

With a focus on carbon steel, which is one of the candidate materials for the disposal container used in the geological disposal of high-level radioactive waste in Japan, the defect detection capabilities were examined regarding engineering defects of the TOFD technique, an ultrasonic testing method, and the phased array TOFD technique as non-destructive test techniques for the inspection of the weld of a carbon steel overpack. Regarding the TOFD technique, a measurement was conducted concerning the influence of the crossing angle of the ultrasonic beams on the capability of detect flaws, for examining the detection characteristics of the technique in relation to the lid structure of an overpack, and it was pointed out that it is appropriate to consider the lower tip of slit as the reference flaw. Based on the measurements and calculations regarding sound pressure distribution, projections about the scope covered by one test session were made and the optimum testing conditions were examined. Regarding the phased array TOFP technique, the detectability and quantification characteristics were investigated, and comparisons with those of the TOFD technique and the phased array UT technique were made. From the viewpoint of securing long-term corrosion resistance for an overpack, the ways of thinking for ensuring the quality and long-term integrity of the final sealing area of a disposal container were examined. This study stresses that identifying and defining the defects that are harmful to corrosion allowance is important as well as achieving improvements in the welding and testing techniques, and that the question to solve in particular from now on is how to establish effective means to detect defects on the weld surface and the near surface and how to approach the level of tolerance concerning the defects on and near the surface. (orig.)

Array-type miniature interferometer as the core optical microsystem of an optical coherence tomography device for tissue inspection

Science.gov (United States)

Passilly, Nicolas; Perrin, Stéphane; Lullin, Justine; Albero, Jorge; Bargiel, Sylwester; Froehly, Luc; Gorecki, Christophe; Krauter, Johann; Osten, Wolfgang; Wang, Wei-Shan; Wiemer, Maik

2016-04-01

Some of the critical limitations for widespread use in medical applications of optical devices, such as confocal or optical coherence tomography (OCT) systems, are related to their cost and large size. Indeed, although quite efficient systems are available on the market, e.g. in dermatology, they equip only a few hospitals and hence, are far from being used as an early detection tool, for instance in screening of patients for early detection of cancers. In this framework, the VIAMOS project aims at proposing a concept of miniaturized, batch-fabricated and lower-cost, OCT system dedicated to non-invasive skin inspection. In order to image a large skin area, the system is based on a full-field approach. Moreover, since it relies on micro-fabricated devices whose fields of view are limited, 16 small interferometers are arranged in a dense array to perform multi-channel simultaneous imaging. Gaps between each channel are then filled by scanning of the system followed by stitching. This approach allows imaging a large area without the need of large optics. It also avoids the use of very fast and often expensive laser sources, since instead of a single point detector, almost 250 thousands pixels are used simultaneously. The architecture is then based on an array of Mirau interferometers which are interesting for their vertical arrangement compatible with vertical assembly at the wafer-level. Each array is consequently a local part of a stack of seven wafers. This stack includes a glass lens doublet, an out-of-plane actuated micro-mirror for phase shifting, a spacer and a planar beam-splitter. Consequently, different materials, such as silicon and glass, are bonded together and well-aligned thanks to lithographic-based fabrication processes.

Continuous-Scan Phased Array Measurement Methods for Turbofan Engine Acoustic Testing, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — ATA Engineering, Inc., (ATA) proposes an SBIR project to advance the technology readiness level (TRL) of a method for measuring phased array acoustic data for...

Development and applications of a computer-aided phased array assembly for ultrasonic testing

International Nuclear Information System (INIS)

Schenk, G.; Montag, H.J.; Wuestenberg, H.; Erhard, A.

1985-01-01

The use of modern electronic equipment for programmable signal delay increasingly allows transit-time controlled phased arrays to be applied in non-destructive, ultrasonic materials testing. A phased-array assembly is described permitting fast variation of incident angle of acoustic wave and of sonic beam focus, together with numerical evaluation of measured data. Phased arrays can be optimized by adding programmable electronic equipment so that the quality of conventional designs can be achieved. Applications of the new technical improvement are explained, referring to stress corrosion cracking, turbine testing, echo tomography of welded joints. (orig./HP) [de

Phase Synchronization for the Mid-Frequency Square Kilometre Array Telescope

Science.gov (United States)

Schediwy, Sascha; Gozzard, David; Stobie, Simon; Gravestock, Charles; Whitaker, Richard; Alachkar, Bassem; Malan, Sias; Boven, Paul; Grainge, Keith

2018-01-01

The Square Kilometre Array (SKA) project is an international effort to build the world’s most sensitive radio telescope operating in the 50 MHz to 14 GHz frequency range. Construction of the SKA has been divided into phases, with the first phase (SKA1) accounting for the first 10% of the telescope's receiving capacity. During SKA1, a low-frequency aperture array comprising over a hundred thousand individual dipole antenna elements will be constructed in Western Australia (SKA1-low), while an array of 197 parabolic-dish antennas, incorporating the 64 dishes of MeerKAT, will be constructed in South Africa (SKA1-mid).Radio telescope arrays such as the SKA require phase-coherent reference signals to be transmitted to each antenna site in the array. In the case of the SKA1-mid, these reference signals will be generated at a central site and transmitted to the antenna sites via fiber-optic cables up to 175 km in length. Environmental perturbations affect the optical path length of the fiber and act to degrade the phase stability of the reference signals received at the antennas, which has the ultimate effect of reducing the fidelity and dynamic range of the data.Since 2011, researchers at the University of Western Australia (UWA) have led the development of an actively-stabilized phase-synchronization system designed specifically to meet the scientific needs and technical challenges of the SKA telescope. Recently this system has been select as the official phase synchronization system for the SKA1-mid telescope. The system is an evolution of Atacama Large Millimeter Array’s distributed ‘photonic local oscillator system’, incorporating key advances made by the international frequency metrology community over the last decade, as well as novel innovations developed by UWA researchers.In this presentation I will describe the technical details of the system; outline how the system's performance was tested using metrology techniques in a laboratory setting, on 186 km

An ultrasonic phased array applicator for deep localized hyperthermia

International Nuclear Information System (INIS)

Ocheltree, K.B.; Benkeser, P.J.; Foster, S.G.; Frizzell, L.A.; Cain, C.A.

1984-01-01

The use of an ultrasonic phased array applicator presents a major advantage over the fixed beam ultrasonic applicators which are typically used for clinical hyperthermia. Such an applicator allows focal region placement in the three dimensional treatment field by electronic steering instead of mechanical movement of the transducer assembly. The design of an array is discussed theoretically, considering that the constraints on grating lobes and power output for hyperthermic applications are quite different from those for imaging. The effects of various design parameters are discussed. Experimental results are presented for several arrays for frequencies under 1 Mhz

Overview of improvements in work practices and instrumentation for CANDU primary heat transport feeders in-service inspections

Energy Technology Data Exchange (ETDEWEB)

Marcotte, O., E-mail: olivier@nucleom.ca [Nucleom Inc., Quebec, Quebec (Canada); Rousseau, G., E-mail: rousseau.gilles.a@hydro.qc.ca [Hydro Quebec, Becancour, Quebec (Canada); Rochefort, E., E-mail: erochfort@zetec.com [Zetec Canada, Quebec, Quebec (Canada)

2013-01-15

The Canadian nuclear industry has developed many advanced non-destructive inspection techniques to be applied safely in hazardous environments in recent years. Automated systems, manual tooling and specialized software modules have been designed since early 2000s to provide complete and very efficient fitness for service inspection of primary heat transport system carbon steel feeder pipes. These techniques deal with complex geometries, difficult access and, radioactive environment. Complementary NDE techniques, namely Ultrasounds, eddy current, phased-array UT and automated scanners are used. This presentation describes the improvements in inspection practices and the advanced data analysis features. (author)

Multiobjective Optimization Method for Multichannel Microwave Components of Active Phased Array Antenna

Directory of Open Access Journals (Sweden)

Lu Wang

2016-01-01

Full Text Available Multichannel microwave components are widely used and the active phased array antenna is a typical representative. The high power generated from T/R modules in active phased array antenna (APAA leads to the degradation of its electrical performances, which seriously restricts the development of high-performance APAA. Therefore, to meet the demand of thermal design for APAA, a multiobjective optimization design model of cold plate is proposed. Furthermore, in order to achieve temperature uniformity and case temperature restrictions of APAA simultaneously, optimization model of channel structure is developed. Besides, an airborne active phased array antenna was tested as an example to verify the validity of the optimization model. The valuable results provide important reference for engineers to enhance thermal design technology of antennas.

An Automated Sensing System for Steel Bridge Inspection Using GMR Sensor Array and Magnetic Wheels of Climbing Robot

Directory of Open Access Journals (Sweden)

Rui Wang

2016-01-01

Full Text Available Corrosion is one of the main causes of deterioration of steel bridges. It may cause metal loss and fatigue cracks in the steel components, which would lead to the collapse of steel bridges. This paper presents an automated sensing system to detect corrosion, crack, and other kinds of defects using a GMR (Giant Magnetoresistance sensor array. Defects will change the relative permeability and electrical conductivity of the material. As a result, magnetic field density generated by ferromagnetic material and the magnetic wheels will be changed. The defects are able to be detected by using GMR sensor array to measure the changes of magnetic flux density. In this study, magnetic wheels are used not only as the adhesion device of the robot, but also as an excitation source to provide the exciting magnetic field for the sensing system. Furthermore, compared to the eddy current method and the MFL (magnetic flux leakage method, this sensing system suppresses the noise from lift-off value fluctuation by measuring the vertical component of induced magnetic field that is perpendicular to the surface of the specimen in the corrosion inspection. Simulations and experimental results validated the feasibility of the system for the automated defect inspection.

Phased array UT (Ultrasonic Testing) used in electricity production plants

International Nuclear Information System (INIS)

Kodaira, Takeshi

2012-01-01

Phased Array-Ultrasonic testing techniques widely used for detection and quantitative determination of the lattice defects which have been formed from fatigues or stress corrosion cracking in the materials used in the electricity production plants are presented with particular focus on the accurate determination of the defects depth (sizing) and defects discrimination applicable to weld metals of austenite stainless steels and Ni base alloys. The principle of this non-destructive analysis is briefly explained, followed by point and matrix focus phased array methods developed by Mitsubishi Heavy Industries, Ltd are explained rather in detail with illustration and the evaluated results. (S. Ohno)

Amplitude and Phase Calibration of an Dual Polarized Active Phased Array Antenna

NARCIS (Netherlands)

Vermeulen, B.C.B.; Paquay, M.H.A.; Koomen, P.J.; Hoogeboom, P.; Snoeij, P.; Pouwels, H.

1996-01-01

In the Netherlands, a Polarimetrie C-band aircraft SAR (Synthetic Aperture Radar) has been developed. The project is called PHARUS, an acronym for Phased Array Universal SAR. This instrument serves remote sensing applications. The antenna system contains 48 modules (expandable to 96). A module is

Optical Techniques for Millimeter-Wave Phased Array Communications Antennas

National Research Council Canada - National Science Library

Edge, Colin

1998-01-01

The scope of this program was to study the application of optical techniques to signal distribution and beamforming networks in phased array antennas for Army mobile tactical communications systems...

Multiple wall-reflection effect in adaptive-array differential-phase reflectometry on QUEST

International Nuclear Information System (INIS)

Idei, H.; Fujisawa, A.; Nagashima, Y.; Onchi, T.; Hanada, K.; Zushi, H.; Mishra, K.; Hamasaki, M.; Hayashi, Y.; Yamamoto, M.K.

2016-01-01

A phased array antenna and Software-Defined Radio (SDR) heterodyne-detection systems have been developed for adaptive array approaches in reflectometry on the QUEST. In the QUEST device considered as a large oversized cavity, standing wave (multiple wall-reflection) effect was significantly observed with distorted amplitude and phase evolution even if the adaptive array analyses were applied. The distorted fields were analyzed by Fast Fourier Transform (FFT) in wavenumber domain to treat separately the components with and without wall reflections. The differential phase evolution was properly obtained from the distorted field evolution by the FFT procedures. A frequency derivative method has been proposed to overcome the multiple-wall reflection effect, and SDR super-heterodyned components with small frequency difference for the derivative method were correctly obtained using the FFT analysis

Voltage splay modes and enhanced phase locking in a modified linear Josephson array

Science.gov (United States)

Harris, E. B.; Garland, J. C.

1997-02-01

We analyze a modified linear Josephson-junction array in which additional unbiased junctions are used to greatly enhance phase locking. This geometry exhibits strong correlated behavior, with an external magnetic field tuning the voltage splay angle between adjacent Josephson oscillators. The array displays a coherent in-phase mode for f=, where f is the magnetic frustration, while for 0tolerant of critical current disorder approaching 100%. The stability of the array has also been studied by computing Floquet exponents. These exponents are found to be negative for all array lengths, with a 1/N2 dependence, N being the number of series-connected junctions.

Friction Stir Weld Inspection Through Conductivity Imaging Using Shaped Field MWM(Registered Trademark) - Arrays

Science.gov (United States)

Goldfine, Neil; Grundy, David; Zilberstein, Vladimir; Kinchen, David G.; McCool, Alex (Technical Monitor)

2002-01-01

Friction Stir Welds (FSW) of Al 2195-T8 and Al 2219-T8, provided by Lockheed Martin Michoud Operations, were inspected for lack-of-penetration (LOP) defects using a custom designed MWM-Array, a multi-element eddy-current sensor. MWM (registered trademark) electrical conductivity mapping demonstrated high sensitivity to LOP as small as 0.75 mm (0.03 in.), as confirmed by metallographic data that characterized the extent of LOP defects. High sensitivity and high spatial resolution was achieved via a 37-element custom designed MWM-Array allowing LOP detection using the normalized longitudinal component of the MWM measured conductivity. This permitted both LOP detection and correlation of MWM conductivity features with the LOP defect size, as changes in conductivity were apparently associated with metallurgical features within the near-surface layer of the LOP defect zone. MWM conductivity mapping reveals information similar to macro-etching as the MWM-Array is sensitive to small changes in conductivity due to changes in microstructure associated with material thermal processing, in this case welding. The electrical conductivity measured on the root side of FSWs varies across the weld due to microstructural differences introduced by the FSW process, as well as those caused by planar flaws. Weld metal, i.e., dynamically recrystallized zone (DXZ), thermomechanically affected zone (TMZ), heat-affected zone (HAZ), and parent metal (PM) are all evident in the conductivity maps. While prior efforts had met with limited success for NDE (Nondestructive Evaluation) of dissimilar alloy, Al2219 to Al2195 FSW, the new custom designed multi-element MWM-Array achieved detection of all LOP defects even in dissimilar metal welds.

A Multi-Band Photonic Phased Array Antenna for High-Data Rate Communication, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Multi-band phased array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. In order to steer...

A Multi-band Photonic Phased Array Antenna for High-Date Rate Communication, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Multi-band phased array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. In order to steer...

Phased arrays: A strategy to lower the energy threshold for neutrinos

Directory of Open Access Journals (Sweden)

Wissel Stephanie

2017-01-01

Full Text Available In-ice radio arrays are optimized for detecting the highest energy, cosmogenic neutrinos expected to be produced though cosmic ray interactions with background photons. However, there are two expected populations of high energy neutrinos: the astrophysical flux observed by IceCube (~1 PeV and the cosmogenic flux (~ 1017 eV or 100 PeV. Typical radio arrays employ a noise-riding trigger, which limits their minimum energy threshold based on the background noise temperature of the ice. Phased radio arrays could lower the energy threshold by combining the signals from several channels before triggering, thereby improving the signal-to-noise at the trigger level. Reducing the energy threshold would allow radio experiments to more efficiently overlap with optical Cherenkov neutrino telescopes as well as for more efficient searches for cosmogenic neutrinos. We discuss the proposed technique and prototypical phased arrays deployed in an anechoic chamber and at Greenland’s Summit Station.

Three-dimensional real-time synthetic aperture imaging using a rotating phased array transducer

DEFF Research Database (Denmark)

Nikolov, Svetoslav; Dufait, Remi; Schoisswohl, Armin

2002-01-01

phased array, which is rotated over the volume of interest. The data is acquired using coded signals and synthetic transmit aperture imaging. Only one group of elements transmits at a time. The delays are set such as to form a cylindrical wave. The back-scattered signal carries information not only from......Current 3D real-time imaging is done either with sparse 2D arrays, or with mechanically moved phased arrays. The former results in a poor resolution and contrast due to a limited amount of elements. The latter has the disadvantage of low frame rates due to the sequential acquisition of the volume...... line-by-line and plane-by-plane. This paper describes an approach which combines mechanically moved phased array with synthetic transmit aperture imaging, resulting in high volume acquisition rates without a trade-off in image quality. The scan method uses a conventional fully populated 64 element...

Sampling phased array - a new technique for ultrasonic signal processing and imaging

OpenAIRE

Verkooijen, J.; Boulavinov, A.

2008-01-01

Over the past 10 years, the improvement in the field of microelectronics and computer engineering has led to significant advances in ultrasonic signal processing and image construction techniques that are currently being applied to non-destructive material evaluation. A new phased array technique, called 'Sampling Phased Array', has been developed in the Fraunhofer Institute for Non-Destructive Testing([1]). It realises a unique approach of measurement and processing of ultrasonic signals. Th...

SAR processing with stepped chirps and phased array antennas.

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin Walter

2006-09-01

Wideband radar signals are problematic for phased array antennas. Wideband radar signals can be generated from series or groups of narrow-band signals centered at different frequencies. An equivalent wideband LFM chirp can be assembled from lesser-bandwidth chirp segments in the data processing. The chirp segments can be transmitted as separate narrow-band pulses, each with their own steering phase operation. This overcomes the problematic dilemma of steering wideband chirps with phase shifters alone, that is, without true time-delay elements.

Slow and fast light in SOA-EA structures for phased-array antennas

DEFF Research Database (Denmark)

Sales, S.; Öhman, Filip; Bermejo, A.

We present an SOA-EA structure for controlling the phase and amplitude of optically fed phased-array antennas. Phase shifts of 40 degrees are obtained through slow and fast light effects by changing only the reverse voltage....

SAFT-assisted sound beam focusing using phased arrays (PA-SAFT) for non-destructive evaluation

Science.gov (United States)

Nanekar, Paritosh; Kumar, Anish; Jayakumar, T.

2015-04-01

Focusing of sound has always been a subject of interest in ultrasonic non-destructive evaluation. An integrated approach to sound beam focusing using phased array and synthetic aperture focusing technique (PA-SAFT) has been developed in the authors' laboratory. The approach involves SAFT processing on ultrasonic B-scan image collected by a linear array transducer using a divergent sound beam. The objective is to achieve sound beam focusing using fewer elements than the ones required using conventional phased array. The effectiveness of the approach is demonstrated on aluminium blocks with artificial flaws and steel plate samples with embedded volumetric weld flaws, such as slag and clustered porosities. The results obtained by the PA-SAFT approach are found to be comparable to those obtained by conventional phased array and full matrix capture - total focusing method approaches.

Dynamic Mode Tuning of Ultrasonic Guided Wave Using an Array Transducer

International Nuclear Information System (INIS)

Kim, Young H.; Song, Sung J.; Park, Joon S.; Kim, Jae H.; Eom, Heung S.

2005-01-01

Ultrasonic guided waves have been widely employed for long range inspection of structures such as plates, rods and pipes. There are numerous modes with different wave velocities, and the appropriate mode selection is one of key techniques in the application of guided waves. In the present work, phase tuning by an array transducer was applied to generate ultrasonic guided waves. For this purpose, 8-channel ultrasonic pulser/receiver and their controller which enables sequential activation of each channels with given time delay were developed. Eight transducers were fabricated in order to generate guided waves by using an array transducer. The selective tuning of wave mode can be achieved by changing the interval between elements of an array transducer

Study on the ultrasonic inspection method using the full matrix capture for the in service railway wheel

Energy Technology Data Exchange (ETDEWEB)

Peng, Jianping; Wang, Li; Zhang, Yu; Gao, Xiaorong; Wang, Zeyong; Peng, Chaoyong [NDT Research Center, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China)

2014-02-18

The quality of wheel is especially important for the safety of high speed railway. In this paper, a new ultrasonic array inspection method, the Full Matrix Capture (FMC) has been studied and applied to the high speed railway wheel inspection, especially in the wheel web from the tread. Firstly, the principle of FMC and TFM algorithm is discussed, and then the new optimization is applied to the standard FMC; Secondly the fundamentals of optimization is described in detail and the performance is analyzed. Finally, the experiment has been built with a standard phased array block and railway wheel, and then the testing results are discussed and analyzed. It is demonstrated that this change for the ultrasonic data acquisition and image reconstruction has higher efficiency and lower cost comparing to the FMC's procedure.

Directional spectrum of ocean waves from array measurements using phase/time/path difference methods

Digital Repository Service at National Institute of Oceanography (India)

Fernandes, A.A.; Sarma, Y.V.B.; Menon, H.B.

Wave direction has for the first time been consistently, accurately and unambiguously evaluated from array measurements using the phase/time/path difference (PTPD) methods of Esteva in case of polygonal arrays and Borgman in case of linear arrays...

Three-dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation

OpenAIRE

Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W. Andy

2016-01-01

Glycoproteins have vast structural diversity which plays an important role in many biological processes and have great potential as disease biomarkers. Here we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase GlycoProtein Array (polyGPA), to specifically capture and profile glycoproteomes, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture pre-oxidized glycan...

Multiband Photonic Phased-Array Antenna

Science.gov (United States)

Tang, Suning

2015-01-01

A multiband phased-array antenna (PAA) can reduce the number of antennas on shipboard platforms while offering significantly improved performance. Crystal Research, Inc., has developed a multiband photonic antenna that is based on a high-speed, optical, true-time-delay beamformer. It is capable of simultaneously steering multiple independent radio frequency (RF) beams in less than 1,000 nanoseconds. This high steering speed is 3 orders of magnitude faster than any existing optical beamformer. Unlike other approaches, this technology uses a single controlling device per operation band, eliminating the need for massive optical switches, laser diodes, and fiber Bragg gratings. More importantly, only one beamformer is needed for all antenna elements.

Manipulating Liquids With Acoustic Radiation Pressure Phased Arrays

Science.gov (United States)

Oeftering, Richard C.

1999-01-01

High-intensity ultrasound waves can produce the effects of "Acoustic Radiation Pressure" (ARP) and "acoustic streaming." These effects can be used to propel liquid flows and to apply forces that can be used to move or manipulate floating objects or liquid surfaces. NASA's interest in ARP includes the remote-control agitation of liquids and the manipulation of bubbles and drops in liquid experiments and propellant systems. A high level of flexibility is attained by using a high-power acoustic phased array to generate, steer, and focus a beam of acoustic waves. This is called an Acoustic Radiation Pressure Phased Array, or ARPPA. In this approach, many acoustic transducer elements emit wavelets that converge into a single beam of sound waves. Electronically coordinating the timing, or "phase shift," of the acoustic waves makes it possible to form a beam with a predefined direction and focus. Therefore, a user can direct the ARP force at almost any desired point within a liquid volume. ARPPA lets experimenters manipulate objects anywhere in a test volume. This flexibility allow it to be used for multiple purposes, such as to agitate liquids, deploy and manipulate drops or bubbles, and even suppress sloshing in spacecraft propellant tanks.

Operational phase of inspection prioritization

International Nuclear Information System (INIS)

Campbell, D.J.; Guthrie, V.H.; Flanagan, G.F.

1986-01-01

Inspectors must make many decisions on the allocation of their efforts. To date, these decisions have been made based upon their own judgment and guidance from inspection procedures. Our goal is to provide probabilistic risk assessment (PRA) information as an additional aid to inspectors. A structured approach for relating PRA information to specific inspection decisions has been developed. The use of PRA information as an aid in optimal decision making: (1) in response to the current plant status and (2) in the scheduling of effort over an extended period of time is considered

Ultraino: An Open Phased-Array System for Narrowband Airborne Ultrasound Transmission.

Science.gov (United States)

Marzo, Asier; Corkett, Tom; Drinkwater, Bruce W

2018-01-01

Modern ultrasonic phased-array controllers are electronic systems capable of delaying the transmitted or received signals of multiple transducers. Configurable transmit-receive array systems, capable of electronic steering and shaping of the beam in near real-time, are available commercially, for example, for medical imaging. However, emerging applications, such as ultrasonic haptics, parametric audio, or ultrasonic levitation, require only a small subset of the capabilities provided by the existing controllers. To meet this need, we present Ultraino, a modular, inexpensive, and open platform that provides hardware, software, and example applications specifically aimed at controlling the transmission of narrowband airborne ultrasound. Our system is composed of software, driver boards, and arrays that enable users to quickly and efficiently perform research in various emerging applications. The software can be used to define array geometries, simulate the acoustic field in real time, and control the connected driver boards. The driver board design is based on an Arduino Mega and can control 64 channels with a square wave of up to 17 Vpp and /5 phase resolution. Multiple boards can be chained together to increase the number of channels. The 40-kHz arrays with flat and spherical geometries are demonstrated for parametric audio generation, acoustic levitation, and haptic feedback.

A Centerless Circular Array Method: Extracting Maximal Information on Phase Velocities of Rayleigh Waves From Microtremor Records From a Simple Seismic Array

Science.gov (United States)

Cho, I.; Tada, T.; Shinozaki, Y.

2005-12-01

We have developed a Centerless Circular Array (CCA) method of microtremor exploration, an algorithm that enables to estimate phase velocities of Rayleigh waves by analyzing vertical-component records of microtremors that are obtained with an array of three or five seismic sensors placed around a circumference. Our CCA method shows a remarkably high performance in long-wavelength ranges because, unlike the frequency-wavenumber spectral method, our method does not resolve individual plane-wave components in the process of identifying phase velocities. Theoretical considerations predict that the resolving power of our CCA method in long-wavelength ranges depends upon the SN ratio, or the ratio of power of the propagating components to that of the non-propagating components (incoherent noise) contained in the records from the seismic array. The applicability of our CCA method to small-sized arrays on the order of several meters in radius has already been confirmed in our earlier work (Cho et al., 2004). We have deployed circular seismic arrays of different sizes at test sites in Japan where the underground structure is well documented through geophysical exploration, and have applied our CCA method to microtremor records to estimate phase velocities of Rayleigh waves. The estimates were then checked against "model" phase velocities that are derived from theoretical calculations. For arrays of 5, 25, 300 and 600 meters in radii, the estimated and model phase velocities demonstrated fine agreement within a broad wavelength range extending from a little larger than 3r (r: the array radius) up to at least 40r, 14r, 42r and 9r, respectively. This demonstrates the applicability of our CCA method to arrays on the order of several to several hundreds of meters in radii, and also illustrates, in a typical way, the markedly high performance of our CCA method in long-wavelength ranges. We have also invented a mathematical model that enables to evaluate the SN ratio in a given

Application of optical processing to adaptive phased array radar

Science.gov (United States)

Carroll, C. W.; Vijaya Kumar, B. V. K.

1988-01-01

The results of the investigation of the applicability of optical processing to Adaptive Phased Array Radar (APAR) data processing will be summarized. Subjects that are covered include: (1) new iterative Fourier transform based technique to determine the array antenna weight vector such that the resulting antenna pattern has nulls at desired locations; (2) obtaining the solution of the optimal Wiener weight vector by both iterative and direct methods on two laboratory Optical Linear Algebra Processing (OLAP) systems; and (3) an investigation of the effects of errors present in OLAP systems on the solution vectors.

Voltage splay modes and enhanced phase locking in a modified linear Josephson array

International Nuclear Information System (INIS)

Harris, E.B.; Garland, J.C.

1997-01-01

We analyze a modified linear Josephson-junction array in which additional unbiased junctions are used to greatly enhance phase locking. This geometry exhibits strong correlated behavior, with an external magnetic field tuning the voltage splay angle between adjacent Josephson oscillators. The array displays a coherent in-phase mode for f=(1)/(2), where f is the magnetic frustration, while for 0 p (f)=2aV dc /Φ 0 (1-2f). The locked splay modes are found to be tolerant of critical current disorder approaching 100%. The stability of the array has also been studied by computing Floquet exponents. These exponents are found to be negative for all array lengths, with a 1/N 2 dependence, N being the number of series-connected junctions. copyright 1996 The American Physical Society

Detecting failed elements on phased array ultrasound transducers using the Edinburgh Pipe Phantom

Science.gov (United States)

Inglis, Scott; Pye, Stephen D

2016-01-01

Aims Imaging faults with ultrasound transducers are common. Failed elements on linear and curvilinear array transducers can usually be detected with a simple image uniformity or ‘paperclip’ test. However, this method is less effective for phased array transducers, commonly used in cardiac imaging. The aim of this study was to assess whether the presence of failed elements could be detected through measurement of the resolution integral (R) using the Edinburgh Pipe Phantom. Methods A 128-element paediatric phased array transducer was studied. Failed elements were simulated using layered polyvinyl chloride (PVC) tape as an attenuator and measurements of resolution integral were carried out for several widths of attenuator. Results All widths of attenuator greater than 0.5 mm resulted in a significant reduction in resolution integral and low contrast penetration measurements compared to baseline (p tests to detect failed elements on phased array transducers. Particularly encouraging is the result for low contrast penetration as this is a quick and simple measurement to make and can be performed with many different test objects, thus enabling ‘in-the-field’ checks. PMID:27482276

Comparison of heating deposition patterns for stacked linear phased array and fixed focus ultrasonic hyperthermia applicators

International Nuclear Information System (INIS)

Ocheltree, K.B.; Benkeser, P.J.; Frizzell, L.A.; Cain, C.A.

1985-01-01

An ultrasonic stacked linear phased array applicator for hyperthermia has been designed to heat tumors at depths from 5 to 10 cm. The power deposition pattern for this applicator is compared to that for a fixed focus applicator for several different scan paths. The power deposition pattern for the stacked linear phased array shows hot spots that are not observed for the mechanically scanned fixed focus applicator. These hot spots are related to the skewed power deposition pattern resulting from scanning the focus off the center of the linear arrays. The overall performance of the stacked linear phased array applicator is compared to that of a fixed focus applicator

Improvement of detection of stress corrosion cracks with ultrasonic phased array probes

International Nuclear Information System (INIS)

Wustenberg, H.; Mohrle, W.; Wegner, W.; Schenk, G.; Erhard, A.

1986-01-01

Probes with linear arrays can be used for the detection of stress corrosion cracks especially if the variability of the sound field is used to change the skewing angle of angle beam probes. The phased array concept can be used to produce a variable skewing angle or a variable angle of incidence depending on the orientation of the linear array on the wedge. This helps to adapt the direction of the ultrasonic beam to probable crack orientations. It has been demonstrated with artificial reflectors as well as with corrosion cracks, that the detection of misoriented cracks can be improved by this approach. The experiences gained during the investigations are encouraging the application of phased array probes for stress corrosion phenomena close to the heat effected zone of welds. Probes with variable skewing angles may find some interesting applications on welds in tubular structures e.g., at off shore constructions and on some difficult geometries within the primary circuit of nuclear power plants

Reconfigurable Transmission Line for a Series-Fed Ku-Band Phased Array Using a Single Feed

Science.gov (United States)

Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda. Felix, A.

2013-01-01

The paper presents a novel approach to realize a lowcost phased array using a simple feeding mechanism. Specifically, a single coplanar stripline (CPS) transmission line is used to feed the antenna array elements. By controlling the CPS's dielectric properties using a movable dielectric plunger, scanning is achieved. Due to its simplicity, single feed, and no phase shifters, this approach leads to a dramatic reduction in cost which does not scale for larger arrays.

An Optimal Beamforming Algorithm for Phased-Array Antennas Used in Multi-Beam Spaceborne Radiometers

DEFF Research Database (Denmark)

Iupikov, O. A.; Ivashina, M. V.; Pontoppidan, K.

2015-01-01

Strict requirements for future spaceborne ocean missions using multi-beam radiometers call for new antenna technologies, such as digital beamforming phased arrays. In this paper, we present an optimal beamforming algorithm for phased-array antenna systems designed to operate as focal plane arrays...... to a FPA feeding a torus reflector antenna (designed under the contract with the European Space Agency) and tested for multiple beams. The results demonstrate an improved performance in terms of the optimized beam characteristics, yielding much higher spatial and radiometric resolution as well as much...

Demonstration of an optical phased array using electro-optic polymer phase shifters

Science.gov (United States)

Hirano, Yoshikuni; Motoyama, Yasushi; Tanaka, Katsu; Machida, Kenji; Yamada, Toshiki; Otomo, Akira; Kikuchi, Hiroshi

2018-03-01

We have been investigating an optical phased array (OPA) using electro-optic (EO) polymers in phase shifters to achieve ultrafast optical beam steering. In this paper, we describe the basic structures of the OPA using EO polymer phase shifters and show the beam steering capability of the OPA. The designed OPA has a multimode interference (MMI) beam splitter and 8-channel polymer waveguides with EO polymer phase shifters. We compare 1 × 8 MMI and cascaded 1 × 2 MMI beam splitters numerically and experimentally, and then obtain uniform intensity outputs from the 1 × 8 beam splitter. We fabricate the EO polymer OPA with a 1 × 8 MMI beam splitter to prevent intensity dispersion due to radiation loss in bending waveguides. We also evaluate the optical beam steering capability of the fabricated OPA and found a 2.7° deflection of far-field patterns when applying a voltage difference of 25 V in adjacent phase shifters.

Analysis and Simulation of Multi-target Echo Signals from a Phased Array Radar

OpenAIRE

Jia Zhen; Zhou Rui

2017-01-01

The construction of digital radar simulation systems has been a research hotspot of the radar field. This paper focuses on theoretical analysis and simulation of multi-target echo signals produced in a phased array radar system, and constructs an array antenna element and a signal generation environment. The antenna element is able to simulate planar arrays and optimizes these arrays by adding window functions. And the signal environment can model and simulate radar transmission signals, rada...

Birefringent Microlens Array for Ultra High Resolution HMDs, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will be used to analyze, design, model, and test a birefringent microlens array for use in a new type of...

Simulation and experiment for depth sizing of cracks in anchor bolts by ultrasonic phased array technology

Science.gov (United States)

Lin, Shan

2018-04-01

There have been lots of reports about the occurrence of cracks in bolts in aging nuclear and thermal power plants. Sizing of such cracks is crucial for assessing the integrity of bolts. Currently, hammering and visual tests are used to detect cracks in bolts. However, they are not applicable for sizing cracks. Although the tip diffraction method is well known as a crack sizing technique, reflection echoes from threads make it difficult to apply this technique to bolts. This paper addresses a method for depth sizing of cracks in bolts by means of ultrasonic phased array technology. Numerical results of wave propagation in bolts by the finite element method (FEM) shows that a peak associated within the vicinity of a crack tip can be observed in the curve of echo intensity versus refraction angle for deep cracks. The refraction angle with respect to this peak decreases as crack depth increases. Such numerical results are verified by experiments on bolt specimens that have electrical discharge machining notches or fatigue cracks with different depths. In the experiment, a 10-MHz linear array probe is used. Depth of cracks in bolts using the refraction angle associated with the peak is determined and compared to actual depths. The comparison shows that accurately determining a crack depth from the inspection results is possible.

Monolithic Microwave Integrated Circuit (MMIC) Phased Array Demonstrated With ACTS

Science.gov (United States)

1996-01-01

Monolithic Microwave Integrated Circuit (MMIC) arrays developed by the NASA Lewis Research Center and the Air Force Rome Laboratory were demonstrated in aeronautical terminals and in mobile or fixed Earth terminals linked with NASA's Advanced Communications Technology Satellite (ACTS). Four K/Ka-band experimental arrays were demonstrated between May 1994 and May 1995. Each array had GaAs MMIC devices at each radiating element for electronic beam steering and distributed power amplification. The 30-GHz transmit array used in uplinks to ACTS was developed by Lewis and Texas Instruments. The three 20-GHz receive arrays used in downlinks from ACTS were developed in cooperation with the Air Force Rome Laboratory, taking advantage of existing Air Force integrated-circuit, active-phased-array development contracts with the Boeing Company and Lockheed Martin Corporation. Four demonstrations, each related to an application of high interest to both commercial and Department of Defense organizations, were conducted. The location, type of link, and the data rate achieved for each of the applications is shown. In one demonstration-- an aeronautical terminal experiment called AERO-X--a duplex voice link between an aeronautical terminal on the Lewis Learjet and ACTS was achieved. Two others demonstrated duplex voice links (and in one case, interactive video links as well) between ACTS and an Army high-mobility, multipurpose wheeled vehicle (HMMWV, or "humvee"). In the fourth demonstration, the array was on a fixed mount and was electronically steered toward ACTS. Lewis served as project manager for all demonstrations and as overall system integrator. Lewis engineers developed the array system including a controller for open-loop tracking of ACTS during flight and HMMWV motion, as well as a laptop data display and recording system used in all demonstrations. The Jet Propulsion Laboratory supported the AERO-X program, providing elements of the ACTS Mobile Terminal. The successful

Phased-array radar design application of radar fundamentals

CERN Document Server

Jeffrey, Thomas

2009-01-01

Phased-Array Radar Design is a text-reference designed for electrical engineering graduate students in colleges and universities as well as for corporate in-house training programs for radar design engineers, especially systems engineers and analysts who would like to gain hands-on, practical knowledge and skills in radar design fundamentals, advanced radar concepts, trade-offs for radar design and radar performance analysis.

Calculation of coupling to slow and fast waves in the LHRF from phased waveguide arrays

International Nuclear Information System (INIS)

Pinsker, R.I.; Duvall, R.E.; Fortgang, C.M.; Colestock, P.L.

1986-04-01

A previously reported algorithm for solving the problem of coupling electromagnetic energy in the LHRF from a phased array of identical rectangular waveguides to a plane-stratified, magnetized cold plasma is numerically implemented. The resulting computer codes are sufficiently general to allow for an arbitrary number of waveguides with finite dimensions in both poloidal and toroidal directions, and are thus capable of computing coupling to both slow and fast waves in the plasma. Some of the details of the implementation and the extension of the algorithm to allow study of the Fourier spectrum of slow and fast waves launched by the array are discussed. Good agreement is found with previously reported, less general work for the slow wave launching case. The effect of phasing multirow arrays in the poloidal direction is studied, and an asymmetry between phasing 'up' and 'down' is found that persists in the case where the plasma adjacent to the array is uniform. A 4 x 3 array designed to launch fast waves of high phase velocity is studied. By using the optimal poloidal phasing, low reflection coefficients (absolute value of R 2 less than or equal to 20%) are found under some not unrealistic edge plasma conditions, but most of the input power is trapped in the outermost layer of the plasma. Implications of our results for fast wave current drive experiments are discussed

GaAs MMIC elements in phased-array antennas

Science.gov (United States)

Leonard, Regis F.

1988-01-01

Over the last six years NASA Lewis Research Center has carried out a program aimed at the development of advanced monolithic microwave integrated circuit technology, principally for use in phased-array antenna applications. Arising out of the Advanced Communications Technology Satellite (ACTS) program, the initial targets of the program were chips which operated at 30 and 20 GHz. Included in this group of activities were monolithic power modules with an output of 2 watts at GHz, variable phase shifters at both 20 and 30 GHz, low noise technology at 30 GHz, and a fully integrated (phase shifter, variable gain amplifier, power amplifier) transmit module at 20 GHz. Subsequent developments are centered on NASA mission requirements, particularly Space Station communications systems and deep space data communications.

Analysis of ultrasonic beam profile due to change of elements' number for phased array transducer (part 2)

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun

1998-01-01

The phased array offers many advantages and improvements over conventional single-element transducers such as the straight-beam and angle-beam. The advantages of array sensors for large structures are two folds; firstly, array transducers provide a method of rapid beam steering and sequential addressing of a large area of interest without requiring mechanical or manual scanning which is particularly important in real-time application. Secondly, array transducer provide a method of dynamic focusing, in which the focal length of the ultrasonic beam varies as the pulse propagates through the material. There are some parameters such as number, size, center to center space of elements to design phased array transducer. In previous study. the characteristics of beam steering and dynamic focusing had been simulated for ultrasonic SH-wave with varying the number of phased array transducer's element. In this study, the characteristic of beam steering for phased array transducer has been simulated for ultrasonic SH-wave on the basis of Huygen's principle with varying center to center space of elements. Ultrasonic beam directivity and focusing due to change of time delay of each element were discussed with varying center to center space of elements.

Combining Simulated and Experimental Data to Simulate Ultrasonic Array Data From Defects in Materials With High Structural Noise.

Science.gov (United States)

Bloxham, Harry A; Velichko, Alexander; Wilcox, Paul David

2016-12-01

Ultrasonic nondestructive testing inspections using phased arrays are performed on a wide range of components and materials. All real inspections suffer, to varying extents, from coherent noise, including image artifacts and speckle caused by complex geometries and grain scatter, respectively. By its nature, this noise is not reduced by averaging; however, it degrades the signal-to-noise ratio of defects and ultimately limits their detectability. When evaluating the effectiveness of an inspection, a large pool of data from samples containing a range of different defects are important to estimate the probability of detection of defects and to help characterize them. For a given inspection, coherent noise is easy to measure experimentally but hard to model realistically. Conversely, the ultrasonic response of defects can be simulated relatively easily. This paper proposes a novel method of simulating realistic array data by combining noise-free simulations of defect responses with coherent noise taken from experimental data. This removes the need for costly physical samples with known defects to be made and allows for large data sets to be created easily.

Image-guided ultrasound phased arrays are a disruptive technology for non-invasive therapy.

Science.gov (United States)

Hynynen, Kullervo; Jones, Ryan M

2016-09-07

Focused ultrasound offers a non-invasive way of depositing acoustic energy deep into the body, which can be harnessed for a broad spectrum of therapeutic purposes, including tissue ablation, the targeting of therapeutic agents, and stem cell delivery. Phased array transducers enable electronic control over the beam geometry and direction, and can be tailored to provide optimal energy deposition patterns for a given therapeutic application. Their use in combination with modern medical imaging for therapy guidance allows precise targeting, online monitoring, and post-treatment evaluation of the ultrasound-mediated bioeffects. In the past there have been some technical obstacles hindering the construction of large aperture, high-power, densely-populated phased arrays and, as a result, they have not been fully exploited for therapy delivery to date. However, recent research has made the construction of such arrays feasible, and it is expected that their continued development will both greatly improve the safety and efficacy of existing ultrasound therapies as well as enable treatments that are not currently possible with existing technology. This review will summarize the basic principles, current statures, and future potential of image-guided ultrasound phased arrays for therapy.

Rail flaw sizing using conventional and phased array ultrasonic testing.

Science.gov (United States)

2012-12-01

An approach to detecting and characterizing internal defects in rail through the use of phased array ultrasonic testing has shown the potential to reduce the risk of missed defects and improve transverse defect characterization. : Transportation Tech...

Photonic integration and components development for a Ku-band phased array antenna system

NARCIS (Netherlands)

Marpaung, D.A.I.; Zhuang, L.; Burla, M.; Roeloffzen, C.G.H.; Noharet, Bertrand; Wang, Qin; Beeker, W.P.; Beeker, Willem; Leinse, Arne; Heideman, Rene

2011-01-01

In this paper the development of a phased array antenna system using a photonic beamformer is reported. The paper emphasizes on the photonic integration between two main components of the beamformer, namely the photonic beamformer chip and the electroabsorption modulator array. System level

One-dimensional phased array with mechanical motion for conformal ultrasound hyperthermia

International Nuclear Information System (INIS)

Ju, Kuen-Cheng; Chen, Yung-Yaw; Lin, Win-Li; Kuo, Te-Son

2003-01-01

This paper investigates the feasibility of conformal heating for external ultrasound hyperthermia by using a phased array transducer with mechanical motion. In this system, a one-dimensional phased array is arranged on a shaft and moves along the shaft, while dynamically focusing on the planning target volume (PTV) with numerous focal spots. To prevent overheating in the intervening tissue between the skin and the PTV, the shaft and the phased array are rotated together to enlarge the acoustical window. With the purpose of conformal heating, the power deposition of the PTV is constructed by combinations of the focal spots and an iterative gradient descent method is then used to determine an optimal set of power weightings for the focal spots. Different tumour shapes are evaluated and the simulation results demonstrate that the volume percentage of the PTV with temperatures higher than 43 deg. C is over 95%. The overheating volume outside the PTV is less than 25% of the PTV. This method provides good conformal heating for external ultrasound hyperthermia. The concept of combining electrical focusing and mechanical motion has the advantages of both enlarging the acoustic window and providing dynamic focusing ability, which is essential for successful conformal heating

Inspection of imprint lithography patterns for semiconductor and patterned media

Science.gov (United States)

Resnick, Douglas J.; Haase, Gaddi; Singh, Lovejeet; Curran, David; Schmid, Gerard M.; Luo, Kang; Brooks, Cindy; Selinidis, Kosta; Fretwell, John; Sreenivasan, S. V.

2010-03-01

Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the requirements of cost-effective device production. This work summarizes the results of defect inspections of semiconductor masks, wafers and hard disks patterned using Jet and Flash Imprint Lithography (J-FILTM). Inspections were performed with optical and e-beam based automated inspection tools. For the semiconductor market, a test mask was designed which included dense features (with half pitches ranging between 32 nm and 48 nm) containing an extensive array of programmed defects. For this work, both e-beam inspection and optical inspection were used to detect both random defects and the programmed defects. Analytical SEMs were then used to review the defects detected by the inspection. Defect trends over the course of many wafers were observed with another test mask using a KLA-T 2132 optical inspection tool. The primary source of defects over 2000 imprints were particle related. For the hard drive market, it is important to understand the defectivity of both the template and the imprinted disk. This work presents a methodology for automated pattern inspection and defect classification for imprint-patterned media. Candela CS20 and 6120 tools from KLA-Tencor map the optical properties of the disk surface, producing highresolution grayscale images of surface reflectivity, scattered light, phase shift, etc. Defects that have been identified in this manner are further characterized according to the morphology

Dynamic Phases in Driven Vortex Lattices in Superconductors with Periodic Pinning Arrays.

Science.gov (United States)

Reichhardt, C.; Olson, C. J.; Nori, F.

1997-03-01

In an extensive series of simulations of driven vortices interacting with periodic pinning arrays, an extremely rich variety of novel plastic flow phases, very distinct from those observed in random arrays, are found as a function of applied driving force. We show that signatures of the transitions between these different dynamical phases appear as pronounced jumps and dips in the I-V curves, coinciding with marked changes in the microscopic structure and flow behavior of the vortex lattice. When the number of vortices is greater than the number of pinning sites, we observe up to six distinct dynamical phases, including a pinned phase, a flow of interstitial vortices between pinned vortices, a disordered flow, a 1D flow along the pinning rows, and a homogeneous flow. By varying a wide range of microscopic pinning parameters, including pinning strength, size, density, and degree of ordering, as well as varying temperature and commensurability, we obtain a series of dynamic phase diagrams. nori>A short video will also be presented to highlight these different dynamic phases.

Three-dimensional mid-air acoustic manipulation by ultrasonic phased arrays.

Science.gov (United States)

Ochiai, Yoichi; Hoshi, Takayuki; Rekimoto, Jun

2014-01-01

The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method.

Phase diagram of a QED-cavity array coupled via a N-type level scheme

Energy Technology Data Exchange (ETDEWEB)

Jin, Jiasen; Rossini, Davide [CNR, NEST, Scuola Normale Superiore and Istituto di Nanoscienze, Pisa (Italy); Fazio, Rosario [CNR, NEST, Scuola Normale Superiore and Istituto di Nanoscienze, Pisa (Italy); National University of Singapore, Center for Quantum Technologies, Singapore (Singapore)

2015-01-01

We study the zero-temperature phase diagram of a one-dimensional array of QED cavities where, besides the single-photon hopping, an additional coupling between neighboring cavities is mediated by an N-type four-level system. By varying the relative strength of the various couplings, the array is shown to exhibit a variety of quantum phases including a polaritonic Mott insulator, a density-wave and a superfluid phase. Our results have been obtained by means of numerical density-matrix renormalization group calculations. The phase diagram was obtained by analyzing the energy gaps for the polaritons, as well as through a study of two-point correlation functions. (orig.)

Intelligent mobile sensor system for drum inspection and monitoring: Phase 1. Topical report, October 1, 1992--June 8, 1993

Energy Technology Data Exchange (ETDEWEB)

1993-06-01

The objective of this project was to develop an operational system for monitoring and inspection activities for waste storage facility operations at several DOE sites. Specifically, the product of this effort is a robotic device with enhanced intelligence and maneuverability capable of conducting routine inspection of stored waste drums. The device is capable of operating in narrow aisles and interpolating the free aisle space between rows of stacked drums. The system has an integrated sensor suite for leak detection, and is interfaced with a site database both for inspection planning and for data correlation, updating, and report generation. The system is capable of departing on an assigned mission, collecting required data, recording which positions of its mission had to be aborted or modified due to environmental constraints, and reporting back when the mission is complete. Successful identification of more than 90% of all drum defects has been demonstrated in a high fidelity waste storage facility mockup. Identified anomalies included rust spots, rust streaks, areas of corrosion, dents, and tilted drums. All drums were positively identified and correlated with the site database. This development effort is separated into three phases of which phase one is now complete. The first phase has demonstrated an integrated system for monitoring and inspection activities for waste storage facility operations. This demonstration system was quickly fielded and evaluated by leveraging technologies developed from previous NASA and DARPA contracts and internal research. The second phase will demonstrate a prototype system appropriate for operational use in an actual storage facility. The prototype provides an integrated design that considers operational requirements, hardware costs, maintenance, safety, and robustness. The final phase will demonstrate commercial viability using the prototype vehicle in a pilot waste operations and inspection project.

Propagation of a radial phased-locked Lorentz beam array in turbulent atmosphere.

Science.gov (United States)

Zhou, Guoquan

2011-11-21

A radial phased-locked (PL) Lorentz beam array provides an appropriate theoretical model to describe a coherent diode laser array, which is an efficient radiation source for high-power beaming use. The propagation of a radial PL Lorentz beam array in turbulent atmosphere is investigated. Based on the extended Huygens-Fresnel integral and some mathematical techniques, analytical formulae for the average intensity and the effective beam size of a radial PL Lorentz beam array are derived in turbulent atmosphere. The average intensity distribution and the spreading properties of a radial PL Lorentz beam array in turbulent atmosphere are numerically calculated. The influences of the beam parameters and the structure constant of the atmospheric turbulence on the propagation of a radial PL Lorentz beam array in turbulent atmosphere are discussed in detail. © 2011 Optical Society of America

POD evaluation using simulation: A phased array UT case on a complex geometry part

Science.gov (United States)

Dominguez, Nicolas; Reverdy, Frederic; Jenson, Frederic

2014-02-01

The use of Probability of Detection (POD) for NDT performances demonstration is a key link in products lifecycle management. The POD approach is to apply the given NDT procedure on a series of known flaws to estimate the probability to detect with respect to the flaw size. A POD is relevant if and only if NDT operations are carried out within the range of variability authorized by the procedure. Such experimental campaigns require collection of large enough datasets to cover the range of variability with sufficient occurrences to build a reliable POD statistics, leading to expensive costs to get POD curves. In the last decade research activities have been led in the USA with the MAPOD group and later in Europe with the SISTAE and PICASSO projects based on the idea to use models and simulation tools to feed POD estimations. This paper proposes an example of application of POD using simulation on the inspection procedure of a complex -full 3D- geometry part using phased arrays ultrasonic testing. It illustrates the methodology and the associated tools developed in the CIVA software. The paper finally provides elements of further progress in the domain.

Supersymmetric phase transition in Josephson-tunnel-junction arrays

Energy Technology Data Exchange (ETDEWEB)

Foda, O.

1988-08-31

The fully frustrated XY model in two dimensions exhibits a vortex-unbinding as well as an Ising transition. If the Ising transition overlaps with the critical line that ends on the vortex transition: T/sub I/less than or equal toT/sub V/, then the model is equivalent, at the overlap temperature, to a free massless field theory of 1 boson and 1 Majorana fermion, which is a superconformal field theory, of central charge c=3/2. The model is experimentally realized in terms of an array of Josephson-tunnel junctions in a transverse magnetic field. The experiment reveals a phase transition consistent with T/sub I/=T/sub V/. Thus, at the critical temperature, the array provides a physical realization of a supersymmetric quantum field theory.

Optical techniques to feed and control GaAs MMIC modules for phased array antenna applications

Science.gov (United States)

Bhasin, K. B.; Anzic, G.; Kunath, R. R.; Connolly, D. J.

1986-01-01

A complex signal distribution system is required to feed and control GaAs monolithic microwave integrated circuits (MMICs) for phased array antenna applications above 20 GHz. Each MMIC module will require one or more RF lines, one or more bias voltage lines, and digital lines to provide a minimum of 10 bits of combined phase and gain control information. In a closely spaced array, the routing of these multiple lines presents difficult topology problems as well as a high probability of signal interference. To overcome GaAs MMIC phased array signal distribution problems optical fibers interconnected to monolithically integrated optical components with GaAs MMIC array elements are proposed as a solution. System architecture considerations using optical fibers are described. The analog and digital optical links to respectively feed and control MMIC elements are analyzed. It is concluded that a fiber optic network will reduce weight and complexity, and increase reliability and performance, but higher power will be required.

Ultrasonic testing with the phased array method at the pipe connection inner edges in pipings

International Nuclear Information System (INIS)

Brekow, G.; Wuestenberg, H.; Hesselmann, H.; Rathgeb, W.

1991-01-01

Ultrasonic testing with the phased array method at the pipe connection inner edges in pipings. The pipe connection inner corner tests in feedwater lines to the main coolant pipe were carried out by Preussen-Elektra in cooperation with Siemens KWU and the BAM with the ultrasonic phased array method. The testing plan was developed by means of a computed model. For a trial of the testing plan, numerous ultrasonic measurements with the phased array method were carried out using a pipe test piece with TH-type inner edges, which was a 1:1 model of the reactor component to be tested. The data measured at several test notches in the pipe connection inner edge area covered by a plating of 6 mm were analyzed. (orig./MM) [de

Phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments

Energy Technology Data Exchange (ETDEWEB)

Nihei, K.T.; Nakagawa, S.; Reverdy, F.; Meyer, L.R.; Duranti, L.; Ball, G.

2010-12-15

Sediments undergoing compaction typically exhibit transversely isotropic (TI) elastic properties. We present a new experimental apparatus, the phased array compaction cell, for measuring the TI elastic properties of clay-rich sediments during compaction. This apparatus uses matched sets of P- and S-wave ultrasonic transducers located along the sides of the sample and an ultrasonic P-wave phased array source, together with a miniature P-wave receiver on the top and bottom ends of the sample. The phased array measurements are used to form plane P-waves that provide estimates of the phase velocities over a range of angles. From these measurements, the five TI elastic constants can be recovered as the sediment is compacted, without the need for sample unloading, recoring, or reorienting. This paper provides descriptions of the apparatus, the data processing, and an application demonstrating recovery of the evolving TI properties of a compacting marine sediment sample.

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

Science.gov (United States)

2017-01-16

hardware. An 8-channel ALSTAR array prototype was constructed and demonstrated to achieve 125.5 dB effective isotropic isolation between broadside...transmit and receive beams over a 100 MHz instantaneous band centered at 2.45 GHz. I. INTRODUCTION A phased array capable of Simultaneous Transmit and...Receive (STAR) could provide significant benefits for many applications including communications, radar, spectral sens- ing, and multifunctional systems

Wireless Power Transfer to a Microaerial Vehicle with a Microwave Active Phased Array

Directory of Open Access Journals (Sweden)

Shotaro Nako

2014-01-01

Full Text Available A wireless power transfer system using a microwave active phased array was developed. In the system, power is transferred to a circling microaerial vehicle (MAV by a microwave beam of 5.8 GHz, which is formed and directed to the MAV using an active phased array antenna. The MAV is expected to support observation of areas that humans cannot reach. The power beam is formed by the phased array with eight antenna elements. Input power is about 5.6 W. The peak power density at 1,500 mm altitude was 2.63 mW/cm2. The power is sent to a circling MAV. Therefore, the transfer beam should be polarized circularly to achieve a constant power supply independent of its yaw angle. To minimize the polarization loss, a sequentially routed antenna (SRA was applied to the transmitter antenna. Results show that the axial ratio of 0.440 dB was accomplished and that power fluctuation was kept below 1%.

Three-dimensional mid-air acoustic manipulation by ultrasonic phased arrays.

Directory of Open Access Journals (Sweden)

Yoichi Ochiai

Full Text Available The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes. The acoustic axis of the ultrasound beam in conventional studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that expanded-polystyrene particles of 0.6 mm, 1 mm, and 2 mm in diameter could be manipulated by our proposed method.

Structural-electrical coupling optimisation for radiating and scattering performances of active phased array antenna

Science.gov (United States)

Wang, Congsi; Wang, Yan; Wang, Zhihai; Wang, Meng; Yuan, Shuai; Wang, Weifeng

2018-04-01

It is well known that calculating and reducing of radar cross section (RCS) of the active phased array antenna (APAA) are both difficult and complicated. It remains unresolved to balance the performance of the radiating and scattering when the RCS is reduced. Therefore, this paper develops a structure and scattering array factor coupling model of APAA based on the phase errors of radiated elements generated by structural distortion and installation error of the array. To obtain the optimal radiating and scattering performance, an integrated optimisation model is built to optimise the installation height of all the radiated elements in normal direction of the array, in which the particle swarm optimisation method is adopted and the gain loss and scattering array factor are selected as the fitness function. The simulation indicates that the proposed coupling model and integrated optimisation method can effectively decrease the RCS and that the necessary radiating performance can be simultaneously guaranteed, which demonstrate an important application value in engineering design and structural evaluation of APAA.

A K/Ka band radiating element for Tx/Rx phased array

KAUST Repository

Sandhu, Ali Imran; Arnieri, E.; Amendola, G.; Boccia, L.; Meniconi, E.; Ziegler, V.

2017-01-01

The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

A K/Ka band radiating element for Tx/Rx phased array

KAUST Repository

Sandhu, Ali Imran

2017-01-20

The paper presents a K/Ka band radiating element for TX/RX phased arrays. Dual band operations is obtained using a single radiating surface: a novel radiator is adopted and placed in a configuration in which dual band and single band elements are interleaved. The array elements are optimized to scan the beam in excess of 50° in both bands. A subarray with 49 Rx elements and 105 Tx elements was built and measured confirming the results obtained in simulations.

Mechanized inspection of steam generator components during manufacture

International Nuclear Information System (INIS)

Otte, H.-J.; Leupoldt, K.; Meister, W.

2009-01-01

Steam Generator (SG) parts are intensively inspected by UT in the course of the manufacturing process. These inspections - mostly performed manually using different codes - are time consuming and call for a sophisticated documentation, figuring part of the life time documentation package. In order to reduce time and costs mechanized inspection equipment is introduced, combining short inspection times, avoiding influence of the human factor and providing proper electronic storage of all inspection results prepared for comparison with data generated during in-service inspection. Since 2001 Cegelec delivered various UT systems for gas turbine disks and rotor ends called SIRO-MAN. Within only a few years the majority of important providers of such components successfully switched from manual inspection to mechanized inspection following the requirements of manufacturers like ALSTOM, GE and Siemens. The SIRO-MAN is now adapted to the needs of mechanized inspection of SG components. The inspection is performed on the products during rotation around the vertical axis. The multi - probe assemblies are manoeuvred on the products by a manipulator system backed by a NC control unit. Acoustic coupling of UT probes to the product surface is performed with oil or water in a closed circuit. UT and - if requested ET - data along with position information of the probe assembly provided by the control unit are acquired, processed and evaluated by an UT / ET electronic system delivered by either Olympus or ZETEC. As performed already on rotor ends a sequence of inspections using different parameter settings can be programmed with simple means (Teach In) so that such inspection sequence can be executed without operating personnel. Probe assemblies allow for individual operation of probes out of the probe assembly according to the individual needs. Conventional UT and phased array applications or combination of both techniques can be provided. The UT / ET electronic equipment offers

Automated Ply Inspection (API) for AFP, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Automated Ply Inspection (API) system autonomously inspects layups created by high speed automated fiber placement (AFP) machines. API comprises a high accuracy...

Standard guide for evaluating performance characteristics of phased-Array ultrasonic testing instruments and systems

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This guide describes procedures for evaluating some performance characteristics of phased-array ultrasonic examination instruments and systems. 1.2 Evaluation of these characteristics is intended to be used for comparing instruments and systems or, by periodic repetition, for detecting long-term changes in the characteristics of a given instrument or system that may be indicative of impending failure, and which, if beyond certain limits, will require corrective maintenance. Instrument characteristics measured in accordance with this guide are expressed in terms that relate to their potential usefulness for ultrasonic examinations. Other electronic instrument characteristics in phased-array units are similar to non-phased-array units and may be measured as described in E 1065 or E 1324. 1.3 Ultrasonic examination systems using pulsed-wave trains and A-scan presentation (rf or video) may be evaluated. 1.4 This guide establishes no performance limits for examination systems; if such acceptance criteria ar...

Efficient coherent beam combination of two-dimensional phase-locked laser arrays

International Nuclear Information System (INIS)

Li, Bing; Yan, Aimin; Liu, Liren; Dai, Enwen; Sun, Jianfeng; Shen, Baoliang; Lv, Xiaoyu; Wu, Yapeng

2011-01-01

An efficient technique in which a two-dimensional (2D) phase-locked laser array can be coherently combined into a high power and high quality beam by using a conjugate Dammann grating (CDG) is presented. A theoretical model is established to provide a physical interpretation of the proposed scheme. Using this technique, we investigate analytically and numerically the coherent combination of 2D laser arrays such as 5 × 5 and 32 × 32 arrangements. Far-field distributions and the near-field pattern of the combined beam are calculated and compared with experimental results. A verification experiment with a simulated 5 × 5 2D laser array using an aperture mask has been performed. Calculations and experimental results show that the proposed technique in this paper is an efficient coherent beam combination method to obtain a high power and high quality beam from laser arrays

Evaluation of Methods for In-Situ Calibration of Field-Deployable Microphone Phased Arrays

Science.gov (United States)

Humphreys, William M.; Lockard, David P.; Khorrami, Mehdi R.; Culliton, William G.; McSwain, Robert G.

2017-01-01

Current field-deployable microphone phased arrays for aeroacoustic flight testing require the placement of hundreds of individual sensors over a large area. Depending on the duration of the test campaign, the microphones may be required to stay deployed at the testing site for weeks or even months. This presents a challenge in regards to tracking the response (i.e., sensitivity) of the individual sensors as a function of time in order to evaluate the health of the array. To address this challenge, two different methods for in-situ tracking of microphone responses are described. The first relies on the use of an aerial sound source attached as a payload on a hovering small Unmanned Aerial System (sUAS) vehicle. The second relies on the use of individually excited ground-based sound sources strategically placed throughout the array pattern. Testing of the two methods was performed in microphone array deployments conducted at Fort A.P. Hill in 2015 and at Edwards Air Force Base in 2016. The results indicate that the drift in individual sensor responses can be tracked reasonably well using both methods. Thus, in-situ response tracking methods are useful as a diagnostic tool for monitoring the health of a phased array during long duration deployments.

Phase Locking and Chaos in a Josephson Junction Array Shunted by a Common Resistance

International Nuclear Information System (INIS)

Tie-Ge, Zhou; Jing, Mao; Ting-Shu, Liu; Yue, Lai; Shao-Lin, Yan

2009-01-01

The dynamics of a Josephson junction array shunted by a common resistance are investigated by using numerical methods. Coexistence of phase locking and chaos is observed in the system when the resistively and capacitively shunted junction model is adopted. The corresponding parameter ranges for phase locking and chaos are presented. When there are three resistively shunted junctions in the array, chaos is found for the first time and the parameter range for chaos is also presented. According to the theory of Chernikov and Schmidt, when there are four or more junctions in the array, the system exhibits chaotic behavior. Our results indicate that the theory of Chernikov and Schmidt is not exactly appropriate. (condensed matter: electronicstructure, electrical, magnetic, and opticalproperties)

Phased Array Ultrasonic Examination of Reactor Coolant System (Carbon Steel-to-CASS) Dissimilar Metal Weld Mockup Specimen

Energy Technology Data Exchange (ETDEWEB)

Crawford, S. L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cinson, A. D. [US Nuclear Regulatory Commission (NRC), Washington, DC (United States); Diaz, A. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, M. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-11-23

In the summer of 2009, Pacific Northwest National Laboratory (PNNL) staff traveled to the Electric Power Research Institute (EPRI) NDE Center in Charlotte, North Carolina, to conduct phased-array ultrasonic testing on a large bore, reactor coolant pump nozzle-to-safe-end mockup. This mockup was fabricated by FlawTech, Inc. and the configuration originated from the Port St. Lucie nuclear power plant. These plants are Combustion Engineering-designed reactors. This mockup consists of a carbon steel elbow with stainless steel cladding joined to a cast austenitic stainless steel (CASS) safe-end with a dissimilar metal weld and is owned by Florida Power & Light. The objective of this study, and the data acquisition exercise held at the EPRI NDE Center, were focused on evaluating the capabilities of advanced, low-frequency phased-array ultrasonic testing (PA-UT) examination techniques for detection and characterization of implanted circumferential flaws and machined reflectors in a thick-section CASS dissimilar metal weld component. This work was limited to PA-UT assessments using 500 kHz and 800 kHz probes on circumferential flaws only, and evaluated detection and characterization of these flaws and machined reflectors from the CASS safe-end side only. All data were obtained using spatially encoded, manual scanning techniques. The effects of such factors as line-scan versus raster-scan examination approaches were evaluated, and PA-UT detection and characterization performance as a function of inspection frequency/wavelength, were also assessed. A comparative assessment of the data is provided, using length-sizing root-mean-square-error and position/localization results (flaw start/stop information) as the key criteria for flaw characterization performance. In addition, flaw signal-to-noise ratio was identified as the key criterion for detection performance.

A supersymmetric phase transition in Josephson-tunnel-junction arrays

International Nuclear Information System (INIS)

Foda, O.

1988-01-01

The fully frustrated XY model in two dimensions exhibits a vortex-unbinding as well as an Ising transition. If the Ising transition overlaps with the critical line that ends on the vortex transition: T I ≤T V , then the model is equivalent, at the overlap temperature, to a free massless field theory of 1 boson and 1 Majorana fermion, which is a superconformal field theory, of central charge c=3/2. The model is experimentally realized in terms of an array of Josephson-tunnel junctions in a transverse magnetic field. The experiment reveals a phase transition consistent with T I =T V . Thus, at the critical temperature, the array provides a physical realization of a supersymmetric quantum field theory. (orig.)

Study of Defect Sizing in Carbon Steel Butt Welds using Conventional Ultrasonic Technique and Phased Array Ultrasonic

International Nuclear Information System (INIS)

Amry Amin Abas; Noorhazleena Azaman; Mohd Yusnisyam Mohd Yusoff

2016-01-01

Ultrasonic testing is a proven reliable method which is able to detect and measure the size of defects in butt welds with acceptable tolerance. Recent advancement of technology has introduced a computerized technique which is phased array. Phased array employs focal law that enable focusing and steering of beam at the active aperture axis. This enables one line scanning but covering the whole weld volume as compared to conventional technique which employs aster scan and multiple probes to completely cover the whole weld volume. Phased array also gives multiple data view which assist the interpreter. This paper is about the study of these two techniques and technical analysis of comparison between the two. The conventional technique is performed using GE USM GO with 4 MHz 45 degrees shear wave probe. The phased array technique uses OLYMPUS OMNISCAN MX2 with 5L64 linear array probe with 16 elements aperture and 55 degrees wedge emitting shear wave into the specimen. Sensitivity of both techniques are based on 1.5 mm Side Drilled Hole. The results are compared and analysis such as defect sizing and defect type determination are performed. (author)

A random phased array device for delivery of high intensity focused ultrasound.

Science.gov (United States)

Hand, J W; Shaw, A; Sadhoo, N; Rajagopal, S; Dickinson, R J; Gavrilov, L R

2009-10-07

Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least +/-15 mm off axis and axially to more than +/-15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci +/-10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm(3) in volume can be produced using the patterns of multiple foci.

A random phased array device for delivery of high intensity focused ultrasound

International Nuclear Information System (INIS)

Hand, J W; Shaw, A; Sadhoo, N; Rajagopal, S; Dickinson, R J; Gavrilov, L R

2009-01-01

Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least ±15 mm off axis and axially to more than ±15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci ±10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm 3 in volume can be produced using the patterns of multiple foci.

Experimental demonstration of conformal phased array antenna via transformation optics.

Science.gov (United States)

Lei, Juan; Yang, Juxing; Chen, Xi; Zhang, Zhiya; Fu, Guang; Hao, Yang

2018-02-28

Transformation Optics has been proven a versatile technique for designing novel electromagnetic devices and it has much wider applicability in many subject areas related to general wave equations. Among them, quasi-conformal transformation optics (QCTO) can be applied to minimize anisotropy of transformed media and has opened up the possibility to the design of broadband antennas with arbitrary geometries. In this work, a wide-angle scanning conformal phased array based on all-dielectric QCTO lens is designed and experimentally demonstrated. Excited by the same current distribution as such in a conventional planar array, the conformal system in presence of QCTO lens can preserve the same radiation characteristics of a planar array with wide-angle beam-scanning and low side lobe level (SLL). Laplace's equation subject to Dirichlet-Neumann boundary conditions is adopted to construct the mapping between the virtual and physical spaces. The isotropic lens with graded refractive index is realized by all-dielectric holey structure after an effective parameter approximation. The measurements of the fabricated system agree well with the simulated results, which demonstrate its excellent wide-angle beam scanning performance. Such demonstration paves the way to a robust but efficient array synthesis, as well as multi-beam and beam forming realization of conformal arrays via transformation optics.

Comparison of pelvic phased-array versus endorectal coil magnetic resonance imaging at 3 Tesla for local staging of prostate cancer.

Science.gov (United States)

Kim, Bum Soo; Kim, Tae-Hwan; Kwon, Tae Gyun; Yoo, Eun Sang

2012-05-01

Several studies have demonstrated the superiority of endorectal coil magnetic resonance imaging (MRI) over pelvic phased-array coil MRI at 1.5 Tesla for local staging of prostate cancer. However, few have studied which evaluation is more accurate at 3 Tesla MRI. In this study, we compared the accuracy of local staging of prostate cancer using pelvic phased-array coil or endorectal coil MRI at 3 Tesla. Between January 2005 and May 2010, 151 patients underwent radical prostatectomy. All patients were evaluated with either pelvic phased-array coil or endorectal coil prostate MRI prior to surgery (63 endorectal coils and 88 pelvic phased-array coils). Tumor stage based on MRI was compared with pathologic stage. We calculated the specificity, sensitivity and accuracy of each group in the evaluation of extracapsular extension and seminal vesicle invasion. Both endorectal coil and pelvic phased-array coil MRI achieved high specificity, low sensitivity and moderate accuracy for the detection of extracapsular extension and seminal vesicle invasion. There were statistically no differences in specificity, sensitivity and accuracy between the two groups. Overall staging accuracy, sensitivity and specificity were not significantly different between endorectal coil and pelvic phased-array coil MRI.

Inspection of copper canisters for spent nuclear fuel by means of ultrasonic array system. Modelling, defect detection and grain noise estimation

International Nuclear Information System (INIS)

Wu Ping; Stepinski, T.

1998-07-01

The work presented in the report has been split into three overlapping tasks which have the following objectives: (1) development of beam-forming tools, and verification of modeling tools; (2) investigation of detection and resolution limits; (3) evaluation of attenuation, estimation and suppression of grain noise. For beam-forming tools, a method of designing steered and/or focused beams in immersed solids is presented based on geometrical acoustics. Presently, the beam designs are only related to delays but not to apodization. These focused, steered beams are intended to be used for sizing defects and inspecting the regions close to canisters outer walls. The modeling tool developed previously for simulating elastic fields radiated by planar arrays into immersed solids has been verified by comparing with the results obtained from PASS, a software developed by Dr. Didier Cassereau, France. The results from our modeling tool are in excellent agreement with those from PASS. Since the array coming with the ALLIN ultrasonic array system is not planar, but cylindrically curved in elevation, and it works not in transmission mode, but in pulse echo mode, the above modeling tool for the planar arrays cannot be applied directly. Therefore, the modeling tool has been upgraded for the ALLIN array. The theory underlying this modeling tool is the extended angular spectrum approach (ASA) which was developed based on the conventional ASA that only applies to planar sources. Experimental verification of the modeling tool has shown that the results from the tool agree very well with the measurements. To quantify the fields from the ALLIN array and to facilitate the comparison of simulated results with the measured ones, the ALLIN array system has been calibrated based on the existing functionality, and an analytical model has been proposed for simulating measured acoustic echo pulses. To investigate the detection and resolution limits, we have carried out a series of experiments

Frequency-domain imaging algorithm for ultrasonic testing by application of matrix phased arrays

Directory of Open Access Journals (Sweden)

Dolmatov Dmitry

2017-01-01

Full Text Available Constantly increasing demand for high-performance materials and systems in aerospace industry requires advanced methods of nondestructive testing. One of the most promising methods is ultrasonic imaging by using matrix phased arrays. This technique allows to create three-dimensional ultrasonic imaging with high lateral resolution. Further progress in matrix phased array ultrasonic testing is determined by the development of fast imaging algorithms. In this article imaging algorithm based on frequency domain calculations is proposed. This approach is computationally efficient in comparison with time domain algorithms. Performance of the proposed algorithm was tested via computer simulations for planar specimen with flat bottom holes.

Evaluation of computer-based NDE techniques and regional support of inspection activities

International Nuclear Information System (INIS)

Taylor, T.T.; Kurtz, R.J.; Heasler, P.G.; Doctor, S.R.

1991-01-01

This paper describes the technical progress during fiscal year 1990 for the program entitled 'Evaluation of Computer-Based nondestructive evaluation (NDE) Techniques and Regional Support of Inspection Activities.' Highlights of the technical progress include: development of a seminar to provide basic knowledge required to review and evaluate computer-based systems; review of a typical computer-based field procedure to determine compliance with applicable codes, ambiguities in procedure guidance, and overall effectiveness and utility; design and fabrication of a series of three test blocks for NRC staff use for training or audit of UT systems; technical assistance in reviewing (1) San Onofre ten year reactor pressure vessel inservice inspection activities and (2) the capability of a proposed phased array inspection of the feedwater nozzle at Oyster Creek; completion of design calculations to determine the feasibility and significance of various sizes of mockup assemblies that could be used to evaluate the effectiveness of eddy current examinations performed on steam generators; and discussion of initial mockup design features and methods for fabricating flaws in steam generator tubes

Examination of measurement and its method of compensation of the sensitivity distribution using phased array coil for body scan

CERN Document Server

Kimura, T; Iizuka, A; Taniguchi, Y; Ishikuro, A; Hongo, T; Inoue, H; Ogura, A

2003-01-01

The influence on the quality of images by measurement of a sensitivity distribution and the use of a sensitivity compensation filter was considered using an opposite-type phased array coil and volume-type phased array coil. With the opposite-type phased array coil, the relation between coil interval and filter was investigated for the image intensity correction (IIC) filter, surface coil intensity correction (SCIC) filter (GE), and the Normalize filter (SIEMENS). The SCIC filter and Normalize filter showed distance dependability over the coil interval of signal-to-noise ratio (SNR) and uniformity was observed, and the existence of an optimal coil interval was suggested. Moreover, with the IIC filter, distance dependability over a coil interval was small, and the decrease in contrast with use was remarkable. On the other hand, with the volume-type phased array coil, the overlap of an array element was investigated to determine the influence it had on sensitivity distribution. Although the value stabilized in t...

An Extended Two-Phase Method for Accessing Sections of Out-of-Core Arrays

Directory of Open Access Journals (Sweden)

Rajeev Thakur

1996-01-01

Full Text Available A number of applications on parallel computers deal with very large data sets that cannot fit in main memory. In such applications, data must be stored in files on disks and fetched into memory during program execution. Parallel programs with large out-of-core arrays stored in files must read/write smaller sections of the arrays from/to files. In this article, we describe a method for accessing sections of out-of-core arrays efficiently. Our method, the extended two-phase method, uses collective l/O: Processors cooperate to combine several l/O requests into fewer larger granularity requests, to reorder requests so that the file is accessed in proper sequence, and to eliminate simultaneous l/O requests for the same data. In addition, the l/O workload is divided among processors dynamically, depending on the access requests. We present performance results obtained from two real out-of-core parallel applications – matrix multiplication and a Laplace's equation solver – and several synthetic access patterns, all on the Intel Touchstone Delta. These results indicate that the extended two-phase method significantly outperformed a direct (noncollective method for accessing out-of-core array sections.

Phase transition in nonuniform Josephson arrays: Monte Carlo simulations

Science.gov (United States)

Lozovik, Yu. E.; Pomirchy, L. M.

1994-01-01

Disordered 2D system with Josephson interactions is considered. Disordered XY-model describes the granular films, Josephson arrays etc. Two types of disorder are analyzed: (1) randomly diluted system: Josephson coupling constants J ij are equal to J with probability p or zero (bond percolation problem); (2) coupling constants J ij are positive and distributed randomly and uniformly in some interval either including the vicinity of zero or apart from it. These systems are simulated by Monte Carlo method. Behaviour of potential energy, specific heat, phase correlation function and helicity modulus are analyzed. The phase diagram of the diluted system in T c-p plane is obtained.

Evidence of hexatic phase formation in two-dimensional Lennard-Jones binary arrays

International Nuclear Information System (INIS)

Li, M.; Johnson, W.L.; Goddard, W.A. III

1996-01-01

We report evidence of the hexatic phase formation in Lennard-Jones binary substitutional random arrays from isothermal-isobaric molecular-dynamics simulations. The hexatic phase is analogous to those predicted in Kosterlitz-Thouless theory of melting that is characterized by short-range translational order and quasi-long-range orientational order. At the crystal to hexatic phase transition, dislocation pairs are observed to unbind into isolated dislocations. Further disordering of the hexatic phase, however, does not lead to dissociation of dislocations into disclinations. Instead, the dislocations become clustered and form dislocation networks which results in formation of amorphous phases. copyright 1996 The American Physical Society

ZnO nanorod array solid phase micro-extraction fiber coating: fabrication and extraction capability

International Nuclear Information System (INIS)

Wang Dan; Zhang Zhuomin; Li Tiemei; Zhang Lan; Chen Guonan; Luo Lin

2009-01-01

In this paper, a ZnO nanorod array has been introduced as a coating to the headspace solid phase micro-extraction (HSSPME) field. The coating shows good extraction capability for volatile organic compounds (VOCs) by use of BTEX as a standard and can be considered suitable for sampling trace and small molecular VOC targets. In comparison with the randomly oriented ZnO nanorod HSSPME coating, ZnO nanorod array HSSPME fiber coating shows better extraction capability, which is attributed to the nanorod array structure of the coating. Also, this novel nanorod array coating shows good extraction selectivity to 1-propanethiol.

Phased Array Noise Source Localization Measurements Made on a Williams International FJ44 Engine

Science.gov (United States)

Podboy, Gary G.; Horvath, Csaba

2010-01-01

A 48-microphone planar phased array system was used to acquire noise source localization data on a full-scale Williams International FJ44 turbofan engine. Data were acquired with the array at three different locations relative to the engine, two on the side and one in front of the engine. At the two side locations the planar microphone array was parallel to the engine centerline; at the front location the array was perpendicular to the engine centerline. At each of the three locations, data were acquired at eleven different engine operating conditions ranging from engine idle to maximum (take off) speed. Data obtained with the array off to the side of the engine were spatially filtered to separate the inlet and nozzle noise. Tones occurring in the inlet and nozzle spectra were traced to the low and high speed spools within the engine. The phased array data indicate that the Inflow Control Device (ICD) used during this test was not acoustically transparent; instead, some of the noise emanating from the inlet reflected off of the inlet lip of the ICD. This reflection is a source of error for far field noise measurements made during the test. The data also indicate that a total temperature rake in the inlet of the engine is a source of fan noise.

National Dam Inspection Program. Laurel Run Dam. NDI ID Number PA-00380. DER ID Number 35-6, Pennsylvania Gas and Water Company. Susquehanna River Basin, Laurel Run, Lackawanna County, Pennsylvania Phase I Inspection Report,

Science.gov (United States)

1980-04-01

Supply. g. Design and Construction History. Laurel Run Dam was constructed in 1594 by Martin Cawley, a contractor from Archbald. The construction was...1T6Ace joly PHASE I INSPECTION REPORT -4 NATIONAL DAM INSPECTION PROGRAM Lime LAUREL RUN DAM PENNSYLVANIA GAS AND WATER COMPANY RESERVOIR AREA

Partially coherent twisted states in arrays of coupled phase oscillators

Energy Technology Data Exchange (ETDEWEB)

Omel' chenko, Oleh E.; Wolfrum, Matthias [Weierstrass Institute, Mohrenstrasse 39, 10117 Berlin (Germany); Laing, Carlo R. [INMS, Massey University, Private Bag 102-904 NSMC, Auckland (New Zealand)

2014-06-15

We consider a one-dimensional array of phase oscillators with non-local coupling and a Lorentzian distribution of natural frequencies. The primary objects of interest are partially coherent states that are uniformly “twisted” in space. To analyze these, we take the continuum limit, perform an Ott/Antonsen reduction, integrate over the natural frequencies, and study the resulting spatio-temporal system on an unbounded domain. We show that these twisted states and their stability can be calculated explicitly. We find that stable twisted states with different wave numbers appear for increasing coupling strength in the well-known Eckhaus scenario. Simulations of finite arrays of oscillators show good agreement with results of the analysis of the infinite system.

Partially coherent twisted states in arrays of coupled phase oscillators

International Nuclear Information System (INIS)

Omel'chenko, Oleh E.; Wolfrum, Matthias; Laing, Carlo R.

2014-01-01

We consider a one-dimensional array of phase oscillators with non-local coupling and a Lorentzian distribution of natural frequencies. The primary objects of interest are partially coherent states that are uniformly “twisted” in space. To analyze these, we take the continuum limit, perform an Ott/Antonsen reduction, integrate over the natural frequencies, and study the resulting spatio-temporal system on an unbounded domain. We show that these twisted states and their stability can be calculated explicitly. We find that stable twisted states with different wave numbers appear for increasing coupling strength in the well-known Eckhaus scenario. Simulations of finite arrays of oscillators show good agreement with results of the analysis of the infinite system

Phase Locking of Laser Diode Array by Using an Off-Axis External Talbot Cavity

International Nuclear Information System (INIS)

Su Zhou-Ping; Zhu Zhuo-Wei; Que Li-Zhi; Zhu Yun; Ji Zhi-Cheng

2012-01-01

Phase locking of a laser diode array is demonstrated experimentally by using an off-axis external Talbot cavity with a feedback plane mirror. Due to good spatial mode discrimination, the cavity does not need a spatial filter. By employing the cavity, a clear and stable far-field interference pattern can be observed when the driver current is less than 14 A. In addition, the spectral line width can be reduced to 0.8 nm. The slope efficiency of the phase-locked laser diode array is about 0.62 W/A. (fundamental areas of phenomenology(including applications))

A review of array radars

Science.gov (United States)

Brookner, E.

1981-10-01

Achievements in the area of array radars are illustrated by such activities as the operational deployment of the large high-power, high-range-resolution Cobra Dane; the operational deployment of two all-solid-state high-power, large UHF Pave Paws radars; and the development of the SAM multifunction Patriot radar. This paper reviews the following topics: array radars steered in azimuth and elevation by phase shifting (phase-phase steered arrays); arrays steered + or - 60 deg, limited scan arrays, hemispherical coverage, and omnidirectional coverage arrays; array radars steering electronically in only one dimension, either by frequency or by phase steering; and array radar antennas which use no electronic scanning but instead use array antennas for achieving low antenna sidelobes.

A simple uniformity test for ultrasound phased arrays.

Science.gov (United States)

Dudley, Nicholas J; Woolley, Darren J

2016-09-01

It is difficult to test phased array ultrasound transducers for non functioning elements. We aimed to modify a widely performed test to improve its ease and effectiveness for these arrays. A paperclip was slowly moved along the transducer array, with the scanner operating in M-mode, imaging at a fundamental frequency with automatic gain and grey scale adjustment disabled. Non-functioning elements are identified by a dark vertical line in the image. The test was repeated several times for each transducer, looking for consistency of results. 2 transducers, with faults already shown by electronic transducer testing, were used to validate the method. 23 transducers in clinical use were tested. The results of the modified test on the 2 faulty transducers agreed closely with electronic transducer testing results. The test indicated faults in 5 of the 23 transducers in clinical use: 3 with a single failed element and 2 with non-uniform sensitivity. 1 transducer with non-uniform sensitivity had undergone lens repair; the new lens was visibly non-uniform in thickness and further testing showed a reduction in depth of penetration and a loss of elevational focus in comparison with a new transducer. The modified test is capable of detecting non-functioning elements. Further work is required to provide a better understanding of more subtle faults. Copyright © 2016 Associazione Italiana di Fisica Medica. All rights reserved.

From PISC to risk informed inspection

International Nuclear Information System (INIS)

Crutzen, S.; Lemaitre, P.; Fabbri, L.

1998-01-01

In this paper the correlation between inspection effectiveness, inspection qualification and risk informed inspection will be treated in view of harmonisation of inspection of nuclear plant components. Through the different phases of the PISC programme the necessity has been demonstrated to show the effectiveness of the inspection through a formal process of qualification in order to ensure that a certain level of effectiveness has been reached. Inspection qualification is indeed the way to quantify the capability level of inspection techniques used. The targets to be met by the inspection is information which should be obtained from risk based analyses. (author)

Ultrasonic inspectability of austenitic stainless steel and dissimilar metal weld joints

Energy Technology Data Exchange (ETDEWEB)

Pudovikov, S.; Bulavinov, A.; Kroening, M. [Fraunhofer-Institut fuer Zerstoerungsfreie Pruefverfahren IZFP, Saarbruecken (Germany)

2008-07-01

Since their invention in 1912, austenitic stainless steel materials are widely used in a variety of industry sectors. In particular, austenitic stainless steel material is qualified to meet the design criteria of high quality, safety related applications, for example, the primary loop of the most of the nuclear power plants in the world, due to high durability and corrosion resistance. Certain operating conditions may cause a range of changes in the integrity of the component, and therefore require nondestructive testing at reasonable intervals. These in-service inspections are often performed using ultrasonic techniques, in particular when cracking is of specific concern. However, the coarse, dendritic grain structure of the weld material, formed during the welding process, is extreme and unpredictably anisotropic. Such structure is no longer direction-independent to the ultrasonic wave propagation; therefore, the ultrasonic beam deflects and redirects and the wave front becomes distorted. Thus, the use of conventional ultrasonic testing techniques using fixed beam angles is very limited and the application of ultrasonic Phased Array techniques becomes desirable. The ''Sampling Phased Array'' technique, invented and developed by Fraunhofer IZFP, allows the acquisition of time signals (A-scans) for each individual transducer element of the array along with image reconstruction techniques using ''SynFoc'' algorithms. The reconstruction considers the sound propagation from each image pixel to the individual sensor element. For anisotropic media, where the sound beam is deflected and the sound path is not known a-priory, we implement a new phase adjustment called ''Reverse Phase Matching'' technique. This algorithm permits the acquisition of phase-corrected A-scans that represent the actual sound propagation in the anisotropic structure; this technique can be utilized for image reconstruction. (orig.)

Sampling phased array, a new technique for ultrasonic signal processing and imaging now available to industry

OpenAIRE

Verkooijen, J.; Bulavinov, A.

2008-01-01

Over the past 10 years the improvement in the field of microelectronics and computer engineering has led to significant advances in ultrasonic signal processing and image construction techniques that are currently being applied to non-destructive material evaluation. A new phased array technique, called "Sampling Phased Array" has been developed in the Fraunhofer Institute for non-destructive testing [1]. It realizes a unique approach of measurement and processing of ultrasonic signals. The s...

Regulatory inspection of the egyptian gamma irradiator using a proposed inspection checklist

International Nuclear Information System (INIS)

Abdel-Ghani, A.H.

2000-01-01

Regulatory inspections are one of the most important elements of a regulatory programme. It shall be performed in all areas of the regulatory responsibility and during all phases of siting, design, construction, commissioning, operation, maintenance and decommissioning of an irradiator facility. The egyptian mega gamma irradiator operating since december 1979 has a Co-60 source of about 400 kilo curies and is used mainly for sterilization of medical supplies and pharmaceuticals and for preservation of some food stuffs. The constructor (Nordion international Inc.) recommended an extensive inspection programme. In accordance with the international and national (2.3) regulations as well as the licensing conditions, the competent authority (NCNSRC) shall perform regulatory inspections both announced and unannounced. In order to facilitate the inspection task and to harmonize the inspection reports a checklist for inspection is proposed which can be used also as an inspection report form

A Two-Radius Circular Array Method: Extracting Independent Information on Phase Velocities of Love Waves From Microtremor Records From a Simple Seismic Array

Science.gov (United States)

Tada, T.; Cho, I.; Shinozaki, Y.

2005-12-01

We have invented a Two-Radius (TR) circular array method of microtremor exploration, an algorithm that enables to estimate phase velocities of Love waves by analyzing horizontal-component records of microtremors that are obtained with an array of seismic sensors placed around circumferences of two different radii. The data recording may be done either simultaneously around the two circles or in two separate sessions with sensors distributed around each circle. Both Rayleigh and Love waves are present in the horizontal components of microtremors, but in the data processing of our TR method, all information on the Rayleigh waves ends up cancelled out, and information on the Love waves alone are left to be analyzed. Also, unlike the popularly used frequency-wavenumber spectral (F-K) method, our TR method does not resolve individual plane-wave components arriving from different directions and analyze their "vector" phase velocities, but instead directly evaluates their "scalar" phase velocities --- phase velocities that contain no information on the arrival direction of waves --- through a mathematical procedure which involves azimuthal averaging. The latter feature leads us to expect that, with our TR method, it is possible to conduct phase velocity analysis with smaller numbers of sensors, with higher stability, and up to longer-wavelength ranges than with the F-K method. With a view to investigating the capabilities and limitations of our TR method in practical implementation to real data, we have deployed circular seismic arrays of different sizes at a test site in Japan where the underground structure is well documented through geophysical exploration. Ten seismic sensors were placed equidistantly around two circumferences, five around each circle, with varying combinations of radii ranging from several meters to several tens of meters, and simultaneous records of microtremors around circles of two different radii were analyzed with our TR method to produce

Phased-array vector velocity estimation using transverse oscillations

DEFF Research Database (Denmark)

Pihl, Michael Johannes; Marcher, Jønne; Jensen, Jørgen Arendt

2012-01-01

.79 to 0.92, indicating a correlation between the performance metrics of the TO spectrum and the velocity estimates. Because these performance metrics are much more readily computed, the TO fields can be optimized faster for improved velocity estimation of both simulations and measurements. For simulations......, but with a poorer performance compared with a 128-element transducer. The simulation and experimental results demonstrate that the TO method is suitable for use in conjunction with a phased-array transducer, and that 2-D vector velocity estimation is possible down to a depth of 15 cm....

Synthesis of Conformal Phased Antenna Arrays With A Novel Multiobjective Invasive Weed Optimization Algorithm

Science.gov (United States)

Li, Wen Tao; Hei, Yong Qiang; Shi, Xiao Wei

2018-04-01

By virtue of the excellent aerodynamic performances, conformal phased arrays have been attracting considerable attention. However, for the synthesis of patterns with low/ultra-low sidelobes of the conventional conformal arrays, the obtained dynamic range ratios of amplitude excitations could be quite high, which results in stringent requirements on various error tolerances for practical implementation. Time-modulated array (TMA) has the advantages of low sidelobe and reduced dynamic range ratio requirement of amplitude excitations. This paper takes full advantages of conformal antenna arrays and time-modulated arrays. The active-element-pattern, including element mutual coupling and platform effects, is employed in the whole design process. To optimize the pulse durations and the switch-on instants of the time-modulated elements, multiobjective invasive weed optimization (MOIWO) algorithm based on the nondominated sorting of the solutions is proposed. A S-band 8-element cylindrical conformal array is designed and a S-band 16-element cylindrical-parabolic conformal array is constructed and tested at two different steering angles.

Damage detection in multilayered fiber-metal laminates using guided-wave phased array

Energy Technology Data Exchange (ETDEWEB)

Maghsoodi, Ameneh; Ohadi, Abdolrezap; Sadighi, Mojtaba; Amindavar, Hamidreza [Amirkabir University, Tehran (Iran, Islamic Republic of)

2016-05-15

This study employs the Lamb wave method to detect damage in Fiber-metal laminates (FMLs). The method is based on quasiisotropic behavior approximation and beam forming techniques. Delay and sum and minimum variance distorsionless response beam formers are applied to a uniform linear phased array. The simulation in finite element software is conducted to evaluate the performance of the presented procedure. The two types of damage studied are the following: (1) Delamination between fiber-epoxy and metal layers and (2) crack on the metal layer. The present study has the following important contributions: (1) Health monitoring of multi-damaged FMLs using Lamb waves and beam forming technique, (2) detection of damage type, (3) detection of damage size by 1D phased array, and (4) identification of damages that occurred very close to the laminate edges or close to each other.

Limitations of Phased Array Beamforming in Open Rotor Noise Source Imaging

Science.gov (United States)

Horvath, Csaba; Envia, Edmane; Podboy, Gary G.

2013-01-01

Phased array beamforming results of the F31/A31 historical baseline counter-rotating open rotor blade set were investigated for measurement data taken on the NASA Counter-Rotating Open Rotor Propulsion Rig in the 9- by 15-Foot Low-Speed Wind Tunnel of NASA Glenn Research Center as well as data produced using the LINPROP open rotor tone noise code. The planar microphone array was positioned broadside and parallel to the axis of the open rotor, roughly 2.3 rotor diameters away. The results provide insight as to why the apparent noise sources of the blade passing frequency tones and interaction tones appear at their nominal Mach radii instead of at the actual noise sources, even if those locations are not on the blades. Contour maps corresponding to the sound fields produced by the radiating sound waves, taken from the simulations, are used to illustrate how the interaction patterns of circumferential spinning modes of rotating coherent noise sources interact with the phased array, often giving misleading results, as the apparent sources do not always show where the actual noise sources are located. This suggests that a more sophisticated source model would be required to accurately locate the sources of each tone. The results of this study also have implications with regard to the shielding of open rotor sources by airframe empennages.

A 4-channel 3 Tesla phased array receive coil for awake rhesus monkey fMRI and diffusion MRI experiments.

Science.gov (United States)

Khachaturian, Mark Haig

2010-01-01

Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major challenges associated with constructing phased array coils for monkeys are the variation in head size and space constraints. Here, we apply phased array technology to a 4-channel phased array coil capable of improving the resolution and image quality of full brain awake monkey fMRI and diffusion MRI experiments. The phased array coil is that can adapt to different rhesus monkey head sizes (ages 4-8) and fits in the limited space provided by monkey stereotactic equipment and provides SNR gains in primary visual cortex and anatomical accuracy in conjunction with parallel imaging and improves resolution in fMRI experiments by a factor of 2 (1.25 mm to 1.0 mm isotropic) and diffusion MRI experiments by a factor of 4 (1.5 mm to 0.9 mm isotropic).

Development of outdoor luminescence imaging for drone-based PV array inspection

DEFF Research Database (Denmark)

Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Thorsteinsson, Sune

2017-01-01

This work has the goal to examined experimentally PV module imaging methods under natural light conditions, that will be used in a fast, accurate and automatic drone-based inspection system for PV power plants.......This work has the goal to examined experimentally PV module imaging methods under natural light conditions, that will be used in a fast, accurate and automatic drone-based inspection system for PV power plants....

Manipulator arm for a nuclear reactor vessel inspection device

International Nuclear Information System (INIS)

1980-01-01

A manipulator arm for a reactor vessel in-service inspection apparatus is adapted to transport a transducer array for ultrasonic examination of welds at any point in the vessel. The removal of the inspection device from the reactor vessel in an emergency presents a problem where a relatively long manipulator arm is used. This invention provides an improved arm with means for changing the normal orientation of the arm to a shorter one to permit safe removal of the inspection device from the reactor vessel. (author)

Optimization of ultrasonic arrays design and setting using a differential evolution

International Nuclear Information System (INIS)

Puel, B.; Chatillon, S.; Calmon, P.; Lesselier, D.

2011-01-01

Optimization of both design and setting of phased arrays could be not so easy when they are performed manually via parametric studies. An optimization method based on an Evolutionary Algorithm and numerical simulation is proposed and evaluated. The Randomized Adaptive Differential Evolution has been adapted to meet the specificities of the non-destructive testing applications. In particular, the solution of multi-objective problems is aimed at with the implementation of the concept of pareto-optimal sets of solutions. The algorithm has been implemented and connected to the ultrasonic simulation modules of the CIVA software used as forward model. The efficiency of the method is illustrated on two realistic cases of application: optimization of the position and delay laws of a flexible array inspecting a nozzle, considered as a mono-objective problem; and optimization of the design of a surrounded array and its delay laws, considered as a constrained bi-objective problem. (authors)

Advances in technologies for feeder pipe inspections

Energy Technology Data Exchange (ETDEWEB)

Ten Grotenhuis, R.; Verma, Y.; Hitchcox, T.; Sakuta, A. [Ontario Power Generation, Inspection and Maintenance Div., Toronto, Ontario (Canada)

2014-07-15

The successful development of the Matrix Inspection Technique (MIT) for feeder weld area applications has been followed up with a project to leverage the technology to address other aspects of feeder inspection. The goal of the project is to adapt the technology to provide full circumferential inspection of feeder pipes for FAC thinning and, potentially, for axial cracking. The project necessitated evolving a new generation of high speed, high element count data acquisition instruments. It also required the development of custom inspection arrays, innovative approaches to sealing the water column, use of inertial motion sensors to synthesize encoder inputs, real-time visual feedback for the operator, and enhanced automated analysis software capable of plotting the inspected configuration in 3D. The individual components of the system are currently being integrated into a whole. The results obtained to date demonstrate the approach to be fundamentally sound. (author)

Superconducting-normal phase boundary of quasicrystalline arrays in a magnetic field

International Nuclear Information System (INIS)

Nori, F.; Niu, Q.; Fradkin, E.; Chang, S.

1987-01-01

We study the effect of frustration, induced by a mangnetic field, on the superconducting diamagnetic properties of two-dimensional quasicrystalline arrays. In particular, we calculate the superconducting-normal phase boundary, T/sub c/(H), for several geometries with quasicrystalline order. The agreement between our theoretically obtained phase boundaries and the experimentally obtained ones is very good. We also propose a new way of analytically analyzing the overall and the fine structure of T/sub c/(H) in terms of short- and long-range correlations among tiles

Thermal therapy for breast tumors by using a cylindrical ultrasound phased array with multifocus pattern scanning: a preliminary numerical study

International Nuclear Information System (INIS)

Ho, C-S; Ju, K-C; Cheng, T-Y; Chen, Y-Y; Lin, W-L

2007-01-01

The purpose of this study is to investigate the feasibility of using a 1 MHz cylindrical ultrasound phased array with multifocus pattern scanning to produce uniform heating for breast tumor thermal therapy. The breast was submerged in water and surrounded by the cylindrical ultrasound phased array. A multifocus pattern was generated and electrically scanned by the phased array to enlarge the treatment lesion in single heating. To prevent overheating normal tissues, a large planning target volume (PTV) would be divided into several planes with several subunits on each plane and sequentially treated with a cooling phase between two successive heatings of the subunit. Heating results for different target temperatures (T tgt ), blood perfusion rates and sizes of the PTV have been studied. Furthermore, a superficial breast tumor with different water temperatures was also studied. Results indicated that a higher target temperature would produce a slightly larger thermal lesion, and a higher blood perfusion rate would not affect the heating lesion size but increase the heating time significantly. The acoustic power deposition and temperature elevations in ribs can be minimized by orienting the acoustic beam from the ultrasound phased array approximately parallel to the ribs. In addition, a large acoustic window on the convex-shaped breast surface for the proposed ultrasound phased array and the cooling effect of water would prevent the skin overheating for the production of a lesion at any desired location. This study demonstrated that the proposed cylindrical ultrasound phased array can provide effective heating for breast tumor thermal therapy without overheating the skin and ribs within a reasonable treatment time

SPS-ALPHA: The First Practical Solar Power Satellite via Arbitrarily Large PHased Array

Data.gov (United States)

National Aeronautics and Space Administration — SPS-ALPHA (Solar Power Satellite via Arbitrarily Large Phased Array) is a novel, bio-mimetic approach to the challenge of space solar power. If successful, this...

Wireless Roadside Inspection Proof of Concept Test Final Report

Energy Technology Data Exchange (ETDEWEB)

Capps, Gary J [ORNL; Franzese, Oscar [ORNL; Knee, Helmut E [ORNL; Plate, Randall S [ORNL; Lascurain, Mary Beth [ORNL

2009-03-01

The U.S. Department of Transportation (DOT) FMCSA commissioned the Wireless Roadside Inspection (WRI) Program to validate technologies and methodologies that can improve safety through inspections using wireless technologies that convey real-time identification of commercial vehicles, drivers, and carriers, as well as information about the condition of the vehicles and their drivers. It is hypothesized that these inspections will: -- Increase safety -- Decrease the number of unsafe commercial vehicles on the road; -- Increase efficiency -- Speed up the inspection process, enabling more inspections to occur, at least on par with the number of weight inspections; -- Improve effectiveness -- Reduce the probability of drivers bypassing CMV inspection stations and increase the likelihood that fleets will attempt to meet the safety regulations; and -- Benefit industry -- Reduce fleet costs, provide good return-on-investment, minimize wait times, and level the playing field. The WRI Program is defined in three phases which are: Phase 1: Proof of Concept Test (POC) Testing of commercially available off-the-shelf (COTS) or near-COTS technology to validate the wireless inspection concept. Phase 2: Pilot Test Safety technology maturation and back office system integration Phase 3: Field Operational Test Multi-vehicle testing over a multi-state instrumented corridor This report focuses on Phase 1 efforts that were initiated in March, 2006. Technical efforts dealt with the ability of a Universal Wireless Inspection System (UWIS) to collect driver, vehicle, and carrier information; format a Safety Data Message Set from this information; and wirelessly transmit a Safety Data Message Set to a roadside receiver unit or mobile enforcement vehicle.

Phased Array Excitations For Efficient Near Field Wireless Power Transmission

Science.gov (United States)

2016-09-01

channeled to the battery or power plant. Figure 2. WPT System Block Diagram for Battery Charging. Source : [2]. Wireless power transfer has gained...EXCITATIONS FOR EFFICIENT NEAR-FIELD WIRELESS POWER TRANSMISSION by Sean X. Hong September 2016 Thesis Advisor: David Jenn Second Reader...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE PHASED ARRAY EXCITATIONS FOR EFFICIENT NEAR-FIELD WIRELESS POWER TRANSMISSION 5

OSE inspection of protection program operations field perspective of inspections

International Nuclear Information System (INIS)

Brown, R.W.; Martin, H.R.

1987-01-01

Protection Program Operations includes three functional areas: Physical Protection Systems, Protective Forces, and System Performance Testing. The Office of Security Evaluations (OSE) inspects field offices in these areas by evaluating programs relative to Standards and Criteria and by performing a variety of exercises and other types of tests to assure protective systems are effective and maintained at a proper level to meet the defined threat. Their perception of the OSE inspections has been positive. The approach taken by ID, with key areas/activities emphasized, during each phase of the field inspection process is described in this report. The most important areas for field offices to concentrate are: inspection preparations through self-evaluation, improving communications, assigning knowledgeable trusted agents, increasing awareness of facility procedures and operations, and assuring daily validations of inspected areas. Emphasis is placed on striving for a balance in reporting both positive and negative findings, and for consistency between ratings and the importance of report findings. OSE efforts to develop improved rating methodologies are encouraged

Linac based photofission inspection system employing novel detection concepts

International Nuclear Information System (INIS)

Stevenson, John; Gozani, Tsahi; Elsalim, Mashal; Condron, Cathie; Brown, Craig

2011-01-01

Rapiscan Systems is developing a LINAC based cargo inspection system for detection of special nuclear material (SNM) in cargo containers. The system, called Photofission Based Alarm Resolution (PBAR) is being developed under a DHD/DNDO Advanced Technology Demonstration (ATD) program. The PBAR system is based on the Rapiscan Eagle P9000 X-ray system, which is a portal system with a commercial 9 MeV LINAC X-ray source. For the purposes of the DNDO ATD program, a conveyor system was installed in the portal to allow scanning and precise positioning of 20 ft ISO cargo containers. The system uses a two step inspection process. In the first step, the basic scan, the container is quickly and completely inspected using two independent radiography arrays: the conventional primary array with high spatial resolution and a lower resolution spectroscopic array employing the novel Z-Spec method. The primary array uses cadmium tungstate (CdWO 4 ) detectors with conventional current mode readouts using photodiodes. The Z-Spec array uses small plastic scintillators capable of performing very fast (up to 10 8 cps) gamma-ray spectroscopy. The two radiography arrays are used to locate high-Z objects in the image such as lead, tungsten, uranium, which could be potential shielding materials as well as SNM itself. In the current system, the Z-Spec works by measuring the energy spectrum of transmitted X-rays. For high-Z materials the higher end of the energy spectrum is more attenuated than for low-Z materials and thus has a lower mean energy and a narrower width than low- and medium-Z materials. The second step in the inspection process is the direct scan or alarm clearing scan. In this step, areas of the container image, which were identified as high Z, are re-inspected. This is done by precisely repositioning the container to the location of the high-Z object and performing a stationary irradiation of the area with X-ray beam. Since there are a large number of photons in the 9 MV

Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

Science.gov (United States)

Yu, Li-Li; Shou, Wen-De; Hui, Chun

2012-02-01

A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed. In this model, the source boundary conditions of the spheroidal beam equation (SBE) for multi-annular phased elements are studied. Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov—Zabolotskaya—Kuznetsov (KZK) model, respectively. Axial dynamic focusing and the harmonic effects are presented. The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field.

Replacement of radiography with ultrasonic phased array for feeder tubes in CANDU reactors using ASME code case N-659-2

International Nuclear Information System (INIS)

Simmons, R.; Bower, Q.; Arseneau, S.

2013-01-01

In this paper we will discuss phased array technology for the replacement of radiography on new construction projects in the nuclear industry. Specifically, through the implementation of A.S.M.E. code N-659-2 and MetaPhase phased array services. Phased Array is not considered a new technique on in service welds in the nuclear industry; however it was unprecedented on new construction welds and required significant investment in regulatory approval (C.N.S.C.), technology research and development, regulatory, client and technician training for successful service implementation. This paper will illustrate the abilities and limitations associated in replacing radiography with MetaPhase, as well as the substantial benefits relative to increased production, improved weld quality, enhanced safety and overall project cost savings. (author)

Reliability considerations of NDT by probability of detection (POD). Determination using ultrasound phased array. Results from a project in frame of the German nuclear safety research program

International Nuclear Information System (INIS)

Kurz, Jochen H.; Dugan, Sandra; Juengert, Anne

2013-01-01

Reliable assessment procedures are an important aspect of maintenance concepts. Non-destructive testing (NDT) methods are an essential part of a variety of maintenance plans. Fracture mechanical assessments require knowledge of flaw dimensions, loads and material parameters. NDT methods are able to acquire information on all of these areas. However, it has to be considered that the level of detail information depends on the case investigated and therefore on the applicable methods. Reliability aspects of NDT methods are of importance if quantitative information is required. Different design concepts e.g. the damage tolerance approach in aerospace already include reliability criteria of NDT methods applied in maintenance plans. NDT is also an essential part during construction and maintenance of nuclear power plants. In Germany, type and extent of inspection are specified in Safety Standards of the Nuclear Safety Standards Commission (KTA). Only certified inspections are allowed in the nuclear industry. The qualification of NDT is carried out in form of performance demonstrations of the inspection teams and the equipment, witnessed by an authorized inspector. The results of these tests are mainly statements regarding the detection capabilities of certain artificial flaws. In other countries, e.g. the U.S., additional blind tests on test blocks with hidden and unknown flaws may be required, in which a certain percentage of these flaws has to be detected. The knowledge of the probability of detection (POD) curves of specific flaws in specific testing conditions is often not present. This paper shows the results of a research project designed for POD determination of ultrasound phased array inspections of real and artificial cracks. The continuative objective of this project was to generate quantitative POD results. The distribution of the crack sizes of the specimens and the inspection planning is discussed, and results of the ultrasound inspections are presented. In

Dual-Polarized Planar Phased Array Analysis for Meteorological Applications

Directory of Open Access Journals (Sweden)

Chen Pang

2015-01-01

Full Text Available This paper presents a theoretical analysis for the accuracy requirements of the planar polarimetric phased array radar (PPPAR in meteorological applications. Among many factors that contribute to the polarimetric biases, four factors are considered and analyzed in this study, namely, the polarization distortion due to the intrinsic limitation of a dual-polarized antenna element, the antenna pattern measurement error, the entire array patterns, and the imperfect horizontal and vertical channels. Two operation modes, the alternately transmitting and simultaneously receiving (ATSR mode and the simultaneously transmitting and simultaneously receiving (STSR mode, are discussed. For each mode, the polarimetric biases are formulated. As the STSR mode with orthogonal waveforms is similar to the ATSR mode, the analysis is mainly focused on the ATSR mode and the impacts of the bias sources on the measurement of polarimetric variables are investigated through Monte Carlo simulations. Some insights of the accuracy requirements are obtained and summarized.

Deep local and regional hyperthermia with annular phased array

International Nuclear Information System (INIS)

Uehara, S.; Omagari, J.; Hata, K.

1989-01-01

33 refractory tumors mainly located in the pelvic cavity after definitive treatment were treated by loco-regional hyperthermia alone (n = 11) or by heat in combination with radiotherapy (n = 22) by annular phased array (APA) manufactured by BSD Corp. Tumors were heated up to more than 42 0 C in 78% of 347 total heat sessions with induction time 22 ± 1 (S.D.) minutes during which those of intra-pelvic organs were elevated up to between 41 and 42 0 C. Tumor response was CR 18%, PR 50% by heat (11.2 ± 1.5 S.D. fractions) combined with radiotherapy (43.8 ± 12.5 S.D. Gy) and by heat alone (8.6 ± 1.3 S.D. fractions) CR 18%, PR 9%. In all heat sessions superficial pain 36%, skin burn (grade 1-2) 12% inside annular array and slight to moderate systemic heat stress 100% were the main adverse reactions we experienced. (orig.)

Luminescence imaging strategies for drone-based PV array inspection

DEFF Research Database (Denmark)

Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Mantel, Claire

2017-01-01

The goal of this work is to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections...

A Partially Magnetized Ferrite LTCC-Based SIW Phase Shifter for Phased Array Applications

KAUST Repository

Ghaffar, Farhan A.

2015-06-01

The theory and design of a half-mode substrate-integrated waveguide ferrite low-temperature cofired ceramic-based phase shifter are presented in this paper. Unlike typical ferrite-based designs, the biasing is done through embedded windings in a multi-layer substrate that not only obviates the requirement of bulky electromagnets, but also prevents loss of bias fields at the air-to-ferrite interface. The phase shifter is operated in the partially magnetized state of ferrite substrate. Through the combined effect of embedded windings, half-mode waveguide operation, and partially magnetized state, the required bias fields have been reduced by 90% as compared with conventional ferrite-based designs employing electromagnets. A complete analytical model, backed up by electromagnetic simulations and measured results from a prototype, is presented in this paper. The fabricated prototype demonstrates a phase shift of 83.2° at a center frequency of 13.1 GHz and a figure of merit of 83.2°/dB. As a proof-of-concept, the proposed phase shifter design is monolithically integrated with a two-element antenna array to demonstrate a measured beam steering of 30°. The phase shifter design is highly efficient in terms of required bias fields, and it has a small form factor and can be easily integrated with other electronic components and systems. © 1965-2012 IEEE.

PHASED ARRAY FEED CALIBRATION, BEAMFORMING, AND IMAGING

International Nuclear Information System (INIS)

Landon, Jonathan; Elmer, Michael; Waldron, Jacob; Jones, David; Stemmons, Alan; Jeffs, Brian D.; Warnick, Karl F.; Richard Fisher, J.; Norrod, Roger D.

2010-01-01

Phased array feeds (PAFs) for reflector antennas offer the potential for increased reflector field of view and faster survey speeds. To address some of the development challenges that remain for scientifically useful PAFs, including calibration and beamforming algorithms, sensitivity optimization, and demonstration of wide field of view imaging, we report experimental results from a 19 element room temperature L-band PAF mounted on the Green Bank 20 Meter Telescope. Formed beams achieved an aperture efficiency of 69% and a system noise temperature of 66 K. Radio camera images of several sky regions are presented. We investigate the noise performance and sensitivity of the system as a function of elevation angle with statistically optimal beamforming and demonstrate cancelation of radio frequency interference sources with adaptive spatial filtering.

Diamagneto-Dielectric Anisotropic Wide Angle Impedance Matching Layers for Active Phased Arrays

NARCIS (Netherlands)

Silvestri, F.; Cifola, L.; Gerini, G.

2016-01-01

In this paper, we present the full process of designing anisotropic metamaterial (MM) wide angle impedance matching (WAIM) layers. These layers are used to reduce the scan losses that occur in active phased arrays for large scanning angles. Numerical results are provided to show the improvement in

Diamagneto-dielectric anisotropic wide angle impedance matching layers for active phased arrays

NARCIS (Netherlands)

Silvestri, F.; Cifola, L.; Gerini, G.

2016-01-01

In this paper we present the full process of designing anisotropic metamaterial (MM) wide angle impedance matching (WAIM) layers. These layers are used to reduce the scan losses that occur in active phased arrays for large scanning angles. Numerical results are provided to show the improvement in

Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

International Nuclear Information System (INIS)

Yu Lili; Shou Wende; Hui Chun

2012-01-01

A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed. In this model, the source boundary conditions of the spheroidal beam equation (SBE) for multi-annular phased elements are studied. Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov-Zabolotskaya-Kuznetsov (KZK) model, respectively. Axial dynamic focusing and the harmonic effects are presented. The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Luminescence Imaging Strategies for Drone-Based PV Array Inspection

DEFF Research Database (Denmark)

Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Mantel, Claire

2017-01-01

) acquisition under natural light conditions during several times of the day, under high sun irradiation, to unveil the sunlight noise characteristics towards an InGaAs detector. In order to bring more freedom to a drone-based inspection, we also show the preliminary results of a laser-line based...

Feasibility study of flexible phased array ultrasonic technology using irregular surface specimen

International Nuclear Information System (INIS)

Lee, Seung Pyo; Moon, Yong Sik; Jung, Nam Du

2015-01-01

Nuclear power plant contain many dissimilar metal welds that connect carbon steel components with stainless steel pipes using alloy 600 welding materials. Primary water stress corrosion cracks at dissimilar metal welds have been continuously reported around the world. In periodic integrity evaluations, dissimilar metal welds are examined using a generic ultrasonic testing procedure, KPD-UT-10. In this procedure, the gap between the probe and examination surface is limited to 1/32 inch (0.8 mm). It is not easy to test some dissimilar metal welds in Korean plants applying ordinary technology because of their tapered shapes and irregular surface conditions. This paper introduces a method for applying a flexible phased array technology to improve the reliability of ultrasonic testing results for various shapes and surface conditions. The artificial flaws in specimens with irregular surfaces were completely detected using the flexible phased array ultrasonic technology. Therefore, it can be said that the technology is applicable to field examination.

Feasibility study of flexible phased array ultrasonic technology using irregular surface specimen

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Pyo; Moon, Yong Sik; Jung, Nam Du [NDE Performance Demonstration Team, Korea Hydro and Nuclear Power, Central Research Institute, Daejeon (Korea, Republic of)

2015-02-15

Nuclear power plant contain many dissimilar metal welds that connect carbon steel components with stainless steel pipes using alloy 600 welding materials. Primary water stress corrosion cracks at dissimilar metal welds have been continuously reported around the world. In periodic integrity evaluations, dissimilar metal welds are examined using a generic ultrasonic testing procedure, KPD-UT-10. In this procedure, the gap between the probe and examination surface is limited to 1/32 inch (0.8 mm). It is not easy to test some dissimilar metal welds in Korean plants applying ordinary technology because of their tapered shapes and irregular surface conditions. This paper introduces a method for applying a flexible phased array technology to improve the reliability of ultrasonic testing results for various shapes and surface conditions. The artificial flaws in specimens with irregular surfaces were completely detected using the flexible phased array ultrasonic technology. Therefore, it can be said that the technology is applicable to field examination.

A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

Directory of Open Access Journals (Sweden)

Ivan Aldaya

2015-01-01

Full Text Available Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

An optical tunable filter array based on LCOS phase grating

Science.gov (United States)

Feng, Dong; Wan, Zhujun; Chen, Xu; Yan, Shijia; Luo, Zhixiang

2018-01-01

This paper reports an optical tunable filter array (TFA) based on a LCOS (liquid crystal on silicon) chip. The input broadband optical beam is first dispersed by a bulk grating and then incident on the LCOS chip. The LCOS chip is phase-only modulated and constructed as a dynamic reflective phase grating. The phase modulation is adjusted to meet the Littrow angle for a specified passband wavelength and thus the optical beam corresponding to this wavelength is steered to the output. The input/output optical beams are coupled to optical fibers with a dual-fiber collimator. Four dualfiber collimators are vertically aligned as the inputs/outputs and the pixels of the LCOS chip are vertically allocated as four independent zones. Thus the device can act as a 4-channel TFA, which is assembled and functionally demonstrated.

Clinical evaluation of phased array multicoil for spine MR imaging

International Nuclear Information System (INIS)

Miller, G.M.; Forbes, G.S.; Onofrio, B.M.; Rasmusson, J.J.

1990-01-01

Often, it is necessary to image the entire spinal canal or cord. Current surface coil technology necessitates a small field of view (FOV) and multiple coil placements, prolonging the examination. The Phased Array Multicoil (General Electric, Milwaukee, Wis) allows for high-resolution imaging of a larger segment of the spinal axis (48 cm), negating the need for multiple coil placements. The purpose of this paper is to determine whether, this technology can produce higher-quality images with equal or better expediency in a high-volume clinical practice. The studies were performed with a modified 1.5-T system (General Electric, Milwaukee, Wis). Multiple small surface coils are electronically linked so that each coil images only a small segment of the spinal column. The individual images are then fused to display one high-resolution 512-matrix image with up to a 48-cm FOV. A variety of four coil arrays were tested, including a 24-cm FOV dedicated cervical coil, 48-cm FOV shaped cervical/thoracic and straight thoracic/lumbar coils, and a six-coil array 75-cm entire spine coil. The images were then evaluated for overall quality, resolution, signal-to-noise ratio, and area of coverage

Switchable Phased Antenna Array with Passive Elements for 5G Mobile Terminals

DEFF Research Database (Denmark)

Syrytsin, Igor A.; Zhang, Shuai; Pedersen, Gert F.

2017-01-01

In this paper, a reconfigurable phased antenna array system is constructed for the mobile terminals in the context of 5G communication system. The proposed antenna system operates at the resonance frequency of 28 GHz. The reconfigurability of the antenna element is achieved by using a passive slot...

Two-dimensional optical phased array antenna on silicon-on-insulator.

Science.gov (United States)

Van Acoleyen, Karel; Rogier, Hendrik; Baets, Roel

2010-06-21

Optical wireless links can offer a very large bandwidth and can act as a complementary technology to radiofrequency links. Optical components nowadays are however rather bulky. Therefore, we have investigated the potential of silicon photonics to fabricated integrated components for wireless optical communication. This paper presents a two-dimensional phased array antenna consisting of grating couplers that couple light off-chip. Wavelength steering of $0.24 degrees /nm is presented reducing the need of active phase modulators. The needed steering range is $1.5 degrees . The 3dB angular coverage range of these antennas is about $0.007pi sr with a directivity of more than 38dBi and antenna losses smaller than 3dB.

Contribution to the development and the modelling of an ultrasonic conformable phased array transducer for the contact inspection of 3D complex geometry components; Contribution au developpement et a la modelisation d'un traducteur ultrasonore multielements conformable pour l'inspection au contact de composants a geometrie complexe 3D

Energy Technology Data Exchange (ETDEWEB)

Guedes, O

2005-04-15

With the difficulties encountered for the exploration of complex shape surfaces, particularly in nuclear industry, the ultrasonic conformable phased array transducer allows a non destructive evaluation of parts with 3D complex parts. For this, one can use the Smart Contact Transducer principle to generate an ultrasonic field by adaptive dynamic focalisation, with a matrix array composed of independent elements moulded in a soft resin. This work deals with the electro-acoustic conception, with the realization of such a prototype and with the study of it's mechanical and acoustic behaviour. The array design is defined using a radiation model adapted to the simulation of contact sources on a free surface. Once one have defined the shape of the radiating elements, a vibratory analysis using finite elements method allows the determination of the emitting structure with 1-3 piezocomposite, witch leads to the realization of emitting-receiving elements. With the measurement of the field transmitted by such elements, we deduced new hypothesis to change the model of radiation. Thus one can take into account normal and tangential stresses calculated with finite element modelling at the interface between the element and the propagation medium, to use it with the semi-analytical model. Some vibratory phenomena dealing with fluid coupling of contact transducers have been studied, and the prediction of the transverse wave radiation profile have been improved. The last part of this work deals with the realization of the first prototype of the conformable phased array transducer. For this a deformation measuring system have been developed, to determine the position of each element on real time with the displacement of the transducer on complex shape surfaces. With those positions, one can perform the calculation of the a delay law intended for the adaptive dynamic focusing of the desired ultrasonic field. The conformable phased array transducer have been characterized in

The Applicability of Incoherent Array Processing to IMS Seismic Array Stations

Science.gov (United States)

Gibbons, S. J.

2012-04-01

The seismic arrays of the International Monitoring System for the CTBT differ greatly in size and geometry, with apertures ranging from below 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high frequency phases since signals are often incoherent between sensors. Many such phases, typically from events at regional distances, remain undetected since pipeline algorithms often consider only frequencies low enough to allow coherent array processing. High frequency phases that are detected are frequently attributed qualitatively incorrect backazimuth and slowness estimates and are consequently not associated with the correct event hypotheses. This can lead to missed events both due to a lack of contributing phase detections and by corruption of event hypotheses by spurious detections. Continuous spectral estimation can be used for phase detection and parameter estimation on the largest aperture arrays, with phase arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity and the ability to estimate backazimuth and slowness requires that the spatial extent of the array is large enough to resolve time-delays between envelopes with a period of approximately 4 or 5 seconds. The NOA, AKASG, YKA, WRA, and KURK arrays have apertures in excess of 20 km and spectrogram beamforming on these stations provides high quality slowness estimates for regional phases without additional post-processing. Seven arrays with aperture between 10 and 20 km (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 second period signal. The MJAR array in Japan recorded high SNR Pn signals for both the 2006 and 2009 North Korea

Infrared microscope inspection apparatus

Science.gov (United States)

Forman, Steven E.; Caunt, James W.

1985-02-26

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

Real-time inspection of metal laminates by means of CNNs

Science.gov (United States)

Preciado, Victor M.; Guinea, Domingo; Montufar-Chaveznava, Rodrigo; Vicente, Jose

2001-04-01

Analog CNN array computer arises as an alternative to traditional digital processors in many industrial inspection like visual quality control of metal laminants, capable of make in a single chip Tera equivalent operations per second. A 4096 analog CNN processor array is able to perform complex space-time image analysis, being much faster than a camera- computer system in continuous inspection applications. Both chips have been implemented in CMOS technology and they are managed by a 32-bit high-performance low-cost micro- controller that closes the pan, tilt, lighting, focus and zoom loops required in the implementation of the active vision strategies. Several convolution masks for the Cellular Processors has been selected to detect particular changes in the texture, size, direction or orientation of the image entities, reprogramming `on the fly' the pixel resolution of shape when necessary. Laboratory results present these Cellular Processors and multiple resolution imager circuits as a promising architecture for visual inspection of industrial processes in real time.

Linac based photofission inspection system employing novel detection concepts

Energy Technology Data Exchange (ETDEWEB)

Stevenson, John, E-mail: jstevenson@rapiscansystems.com [Rapiscan Laboratories, Inc., 520 Almanor Avenue, Sunnyvale, CA 94085 (United States); Gozani, Tsahi, E-mail: tgozani@rapiscansystems.com [Rapiscan Laboratories, Inc., 520 Almanor Avenue, Sunnyvale, CA 94085 (United States); Elsalim, Mashal; Condron, Cathie; Brown, Craig [Rapiscan Laboratories, Inc., 520 Almanor Avenue, Sunnyvale, CA 94085 (United States)

2011-10-01

Rapiscan Systems is developing a LINAC based cargo inspection system for detection of special nuclear material (SNM) in cargo containers. The system, called Photofission Based Alarm Resolution (PBAR) is being developed under a DHD/DNDO Advanced Technology Demonstration (ATD) program. The PBAR system is based on the Rapiscan Eagle P9000 X-ray system, which is a portal system with a commercial 9 MeV LINAC X-ray source. For the purposes of the DNDO ATD program, a conveyor system was installed in the portal to allow scanning and precise positioning of 20 ft ISO cargo containers. The system uses a two step inspection process. In the first step, the basic scan, the container is quickly and completely inspected using two independent radiography arrays: the conventional primary array with high spatial resolution and a lower resolution spectroscopic array employing the novel Z-Spec method. The primary array uses cadmium tungstate (CdWO{sub 4}) detectors with conventional current mode readouts using photodiodes. The Z-Spec array uses small plastic scintillators capable of performing very fast (up to 10{sup 8} cps) gamma-ray spectroscopy. The two radiography arrays are used to locate high-Z objects in the image such as lead, tungsten, uranium, which could be potential shielding materials as well as SNM itself. In the current system, the Z-Spec works by measuring the energy spectrum of transmitted X-rays. For high-Z materials the higher end of the energy spectrum is more attenuated than for low-Z materials and thus has a lower mean energy and a narrower width than low- and medium-Z materials. The second step in the inspection process is the direct scan or alarm clearing scan. In this step, areas of the container image, which were identified as high Z, are re-inspected. This is done by precisely repositioning the container to the location of the high-Z object and performing a stationary irradiation of the area with X-ray beam. Since there are a large number of photons in the 9

Automated ultrasonic shop inspection of reactor pressure vessel forgings

International Nuclear Information System (INIS)

Farley, J.M.; Dikstra, B.J.; Hanstock, D.J.; Pople, C.H.

1986-01-01

Automated ultrasonic shop inspection utilizing a computer-controlled system is being applied to each of the forgings for the reactor pressure vessel of the proposed Sizewell B PWR power station. Procedures which utilize a combination of high sensitivity shear wave pulse echo, 0 degrees and 70 degrees angled longitudinal waves, tandem and through-thickness arrays have been developed to provide comprehensive coverage and an overall reliability of inspection comparable to the best achieved in UKAEA defect detection trials and in PISC II. This paper describes the ultrasonic techniques, the automated system (its design, commissioning and testing), validation and the progress of the inspections

Microwave Inspection Nondestructive Imaging Array, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — To address the NASA need for advanced NDE sensor technologies for structural materials, Physical Optics Corporation (POC) proposes to develop a new Microwave...

Nonequilibriun Dynamic Phases of Driven Vortex Lattices in Superconductors with Periodic Pinning Arrays

Science.gov (United States)

Reichhardt, C.; Olson, C. J.; Nori, F.

1998-03-01

We present results from extensive simulations of driven vortex lattices interacting with periodic pinning arrays. Changing an applied driving force produces an exceptionally rich variety of distinct dynamic phases which include over a dozen well defined plastic flow phases. Transitions between different dynamical phases are marked by sharp jumps in the V(I) curves that coincide with distinct changes in the vortex trajectories and vortex lattice order. A series of dynamical phase diagrams are presented which outline the onset of the different dynamical phases (C. Reichhardt, C.J. Olson, and F. Nori, Phys. Rev. Lett. 78), 2648 (1997); and to be published. Videos are avaliable at http://www-personal.engin.umich.edu/ñori/. Using force balance arguments, several of the phase boundaries can be derived analyticaly.

Synthesis of Phase-Only Reconfigurable Linear Arrays Using Multiobjective Invasive Weed Optimization Based on Decomposition

Directory of Open Access Journals (Sweden)

Yan Liu

2014-01-01

Full Text Available Synthesis of phase-only reconfigurable array aims at finding a common amplitude distribution and different phase distributions for the array to form different patterns. In this paper, the synthesis problem is formulated as a multiobjective optimization problem and solved by a new proposed algorithm MOEA/D-IWO. First, novel strategies are introduced in invasive weed optimization (IWO to make original IWO fit for solving multiobjective optimization problems; then, the modified IWO is integrated into the framework of the recently well proved competitive multiobjective optimization algorithm MOEA/D to form a new competitive MOEA/D-IWO algorithm. At last, two sets of experiments are carried out to illustrate the effectiveness of MOEA/D-IWO. In addition, MOEA/D-IWO is compared with MOEA/D-DE, a new version of MOEA/D. The comparing results show the superiority of MOEA/D-IWO and indicate its potential for solving the antenna array synthesis problems.

A Phased Array Approach to Rock Blasting

Energy Technology Data Exchange (ETDEWEB)

Leslie Gertsch; Jason Baird

2006-07-01

A series of laboratory-scale simultaneous two-hole shots was performed in a rock simulant (mortar) to record the shock wave interference patterns produced in the material. The purpose of the project as a whole was to evaluate the usefulness of phased array techniques of blast design, using new high-precision delay technology. Despite high-speed photography, however, we were unable to detect the passage of the shock waves through the samples to determine how well they matched the expected interaction geometry. The follow-up mine-scale tests were therefore not conducted. Nevertheless, pattern analysis of the vectors that would be formed by positive interference of the shockwaves from multiple charges in an ideal continuous, homogeneous, isotropic medium indicate the potential for powerful control of blast design, given precise characterization of the target rock mass.

Development of Radar Control system for Multi-mode Active Phased Array Radar for atmospheric probing

Science.gov (United States)

Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.

2016-07-01

Modern multi-mode active phased array radars require highly efficient radar control system for hassle free real time radar operation. The requirement comes due to the distributed architecture of the active phased array radar, where each antenna element in the array is connected to a dedicated Transmit-Receive (TR) module. Controlling the TR modules, which are generally few hundreds in number, and functioning them in synchronisation, is a huge task during real time radar operation and should be handled with utmost care. Indian MST Radar, located at NARL, Gadanki, which is established during early 90's, as an outcome of the middle atmospheric program, is a remote sensing instrument for probing the atmosphere. This radar has a semi-active array, consisting of 1024 antenna elements, with limited beam steering, possible only along the principle planes. To overcome the limitations and difficulties, the radar is being augmented into fully active phased array, to accomplish beam agility and multi-mode operations. Each antenna element is excited with a dedicated 1 kW TR module, located in the field and enables to position the radar beam within 20° conical volume. A multi-channel receiver makes the radar to operate in various modes like Doppler Beam Swinging (DBS), Spaced Antenna (SA), Frequency Domain Interferometry (FDI) etc. Present work describes the real-time radar control (RC) system for the above described active phased array radar. The radar control system consists of a Spartan 6 FPGA based Timing and Control Signal Generator (TCSG), and a computer containing the software for controlling all the subsystems of the radar during real-time radar operation and also for calibrating the radar. The main function of the TCSG is to generate the control and timing waveforms required for various subsystems of the radar. Important components of the RC system software are (i) TR module configuring software which does programming, controlling and health parameter monitoring of the

Intracavitary ultrasound phased arrays for prostate thermal therapies: MRI compatibility and in vivo testing.

Science.gov (United States)

Hutchinson, E B; Hynynen, K

1998-12-01

A 62 element MRI-compatible linear phased array was designed and constructed to investigate the feasibility of using transrectal ultrasound for the thermal therapeutic treatment of prostate cancer and benign prostatic hyperplasia. An aperiodic design technique developed in a previous study was used in the design of this array, which resulted in reduced grating lobe levels by using an optimized random distribution of unequally sized elements. The element sizes used in this array were selected to be favorable for both grating lobe levels as determined by array aperiodicity and array efficiency as determined by width to thickness ratios. The heating capabilities and MRI compatibility of the array were tested with in vivo rabbit thigh muscle heating experiments using MRI temperature monitoring. The array produced therapeutic temperature elevations in vivo at depths of 3-6 cm and axial locations up to 3 cm off the central axis and increased the size of the heated volume with electronic scanning of a single focus. The ability of this array to be used for ultrasound surgery was demonstrated by creating necrosed tissue lesions in vivo using short high-power sonications. The ability of the array to be used for hyperthermia was demonstrated by inducing therapeutic temperature elevations for longer exposures. Based on the acoustic and heating performance of this array, it has the potential to be clinically useful for delivering thermal therapies to the prostate and other target volumes close to body cavities.

Enabling inspection solutions for future mask technologies through the development of massively parallel E-Beam inspection

Science.gov (United States)

Malloy, Matt; Thiel, Brad; Bunday, Benjamin D.; Wurm, Stefan; Jindal, Vibhu; Mukhtar, Maseeh; Quoi, Kathy; Kemen, Thomas; Zeidler, Dirk; Eberle, Anna Lena; Garbowski, Tomasz; Dellemann, Gregor; Peters, Jan Hendrik

2015-09-01

need for high-speed e-beam inspection and then provides initial imaging results from EUV masks and wafers from 61 and 91 beam demonstration systems. Progress towards high resolution and consistent intentional defect arrays (IDA) is also shown.

Transverse phase-locking in fully frustrated Josephson junction arrays: A new type of fractional giant steps

International Nuclear Information System (INIS)

Marconi, Veronica I.; Kolton, Alejandro B.; Dominguez, Daniel; Gronbech-Jensen, Niels

2003-05-01

We study, analytically and numerically, phase locking of driven vortex lattices in fully-frustrated Josephson junction arrays at zero temperature. We consider the case when an ac current is applied perpendicular to a dc current. We observe phase locking, steps in the current-voltage characteristics, with a dependence on external ac-drive amplitude and frequency qualitatively different from the Shapiro steps, observed when the ac and dc currents are applied in parallel. Further, the critical current increases with increasing transverse ac-drive amplitude, while it decreases for longitudinal ac-drive. The critical current and the phase-locked current step width, increase quadratically with (small) amplitudes of the ac-drive. For larger amplitudes of the transverse ac-signal, we find windows where the critical current is hysteretic, and windows where phase locking is suppressed due to dynamical instabilities. We characterize the dynamical states around the phase-locking interference condition in the IV curve with voltage noise, Lyapunov exponents and Poincare sections. We find that zero temperature phase-locking behavior in large fully frustrated arrays is well described by an effective four plaquette model. (author)

Low energy microcolumn for large field view inspection

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Chul [Department of Optometry, Eulji University, 212 Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 461-713 (Korea, Republic of); Ahn, Seung-Joon; Oh, Tae-Sik; Kim, Dae-Wook [Department of Nanoscience, Sun Moon University 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Kim, Ho-Seob, E-mail: hskim3@sunmoon.ac.kr [Department of Nanoscience, Sun Moon University 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Jang, Won Kweon [Division of Electronic, Computer and Communication Engineering, Hanseo University 360 DaeKook-ri, Haemi-myun, Seosan-si, Chungnam 356-706 (Korea, Republic of)

2011-12-15

Since the development of microcolumn system, it attracted much attention because multiple microcolumns can be assembled into arrayed form, which is expected to generate multiple electron beams and overcome the disadvantage of electron beam inspection equipments, low throughput . However, it is not easy to apply a microcolumn to the practical inspection or testing equipment since its scanning area is too small. Even if the arrayed operation using multiple microcolumns can overcome this limit, it requires complicated supporting systems and related technologies to operate a number of microcolumns simultaneously. Therefore, we tried to modify microcolumn design itself so that it can have a large field of view. In this work, two kinds of modified columns will be suggested and the preliminary results showing their performance of scanning large area will be discussed. -- Highlights: Black-Right-Pointing-Pointer Two types of microcolumn designs to achieve a large field of view are fabricated. Black-Right-Pointing-Pointer Field of view of a microcolumn increases linearly with the working distance. Black-Right-Pointing-Pointer New designed microcolumns can be developed as a low energy column system for large view inspections.

Phase and Frequency Control of Laser Arrays for Pulse Synthesis

Science.gov (United States)

2015-01-02

SUBTITLE Phase and Frequency Control of Laser Arrays for Pulse Synthesis 875 North Randolph Street Arlington VA 22203-1768 5a. CONTRACT NUMBER...Hachtel, M. Gillette, J. Barkeloo, E. Clements, S. Bali , B. Unks, N. Proite, D. Yavuz, P. Martin, J. Thorn, and D. Steck, Am. J. Phys., 82, 805 (2014...Opt. 37, 4871-4875 (1998). 17. J. Kangara, A. Hachtel, M. Gillette, J. Barkeloo, E. Clements, S. Bali , B. Unks, N. Proite, D. Yavuz, P. Martin, J

Three-Dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation.

Science.gov (United States)

Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W Andy

2016-11-30

Glycoproteins have vast structural diversity that plays an important role in many biological processes and have great potential as disease biomarkers. Here, we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase glycoprotein array (polyGPA), to capture and profile glycoproteomes specifically, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture preoxidized glycans on glycoproteins from complex protein samples such as biofluids. The captured glycoproteins were subsequently detected using the same validated antibodies as in RPPA. We demonstrated the outstanding specificity, sensitivity, and quantitative capabilities of polyGPA by capturing and detecting purified as well as endogenous α-1-acid glycoprotein (AGP) in human plasma. We further applied quantitative N-glycoproteomics and the strategy to validate a panel of glycoproteins identified as potential biomarkers for bladder cancer by analyzing urine glycoproteins from bladder cancer patients or matched healthy individuals.

Model Building of Photovoltaic Array with MPPT Function and Research on Single Phase Grid Connected

Directory of Open Access Journals (Sweden)

Li Zhengzhou

2016-01-01

Full Text Available With the continued development of solar photovoltaic technology, research on distributed grid connected photovoltaic system has become a research focus in the field of photovoltaic grid power plant and the computer simulation technology is an effective technology means in the study. On the basis of the photovoltaic array output characteristic equation, the photovoltaic array maximum power control simulation model based on M function is established by using MATLAB/Simulink and the simulation model of single phase grid connected photovoltaic array is proposed. It overcomes the shortcomings of the process of building the model of the PV array by using Simulink component library and provides the basic guarantee for the realization of system simulation, guiding theory research and system design.

A Small Ku-Band Polarization Tracking Active Phased Array for Mobile Satellite Communications

Directory of Open Access Journals (Sweden)

Wei Shi

2013-01-01

Full Text Available A compact polarization tracking active phased array for Ku-band mobile satellite signal reception is presented. In contrast with conventional mechanically tracking antennas, the approach presented here meets the requirements of beam tracking and polarization tracking simultaneously without any servo components. The two-layer stacked square patch fed by two probes is used as antenna element. The impedance bandwidth of 16% for the element covers the operating frequency range from 12.25 GHz to 12.75 GHz. In the presence of mutual coupling, the dimensional parameters for each element of the small 7 × 7 array are optimized during beam scanning and polarization tracking. The compact polarization tracking modules based on the low-temperature cofired ceramic (LTCC system-in-package (SiP technology are proposed. A small active phased array prototype with the size of 120 mm (length × 120 mm (width × 55 mm (height is developed. The measured polarization tracking patterns of the prototype are given. The polarization tracking beam can be steered in the elevation up to 50°. The gain of no less than 16.0 dBi and the aperture efficiency of more than 50% are obtained. The measured and simulated polarization tracking patterns agreed well.

Ambiguity Resolution for Phase-Based 3-D Source Localization under Fixed Uniform Circular Array.

Science.gov (United States)

Chen, Xin; Liu, Zhen; Wei, Xizhang

2017-05-11

Under fixed uniform circular array (UCA), 3-D parameter estimation of a source whose half-wavelength is smaller than the array aperture would suffer from a serious phase ambiguity problem, which also appears in a recently proposed phase-based algorithm. In this paper, by using the centro-symmetry of UCA with an even number of sensors, the source's angles and range can be decoupled and a novel algorithm named subarray grouping and ambiguity searching (SGAS) is addressed to resolve angle ambiguity. In the SGAS algorithm, each subarray formed by two couples of centro-symmetry sensors can obtain a batch of results under different ambiguities, and by searching the nearest value among subarrays, which is always corresponding to correct ambiguity, rough angle estimation with no ambiguity is realized. Then, the unambiguous angles are employed to resolve phase ambiguity in a phase-based 3-D parameter estimation algorithm, and the source's range, as well as more precise angles, can be achieved. Moreover, to improve the practical performance of SGAS, the optimal structure of subarrays and subarray selection criteria are further investigated. Simulation results demonstrate the satisfying performance of the proposed method in 3-D source localization.

Project inspection using mobile technology - phase I : an investigation into existing business processes and areas for improvement using mobile technology.

Science.gov (United States)

2013-08-01

As mobile technology becomes widely available and affordable, transportation agencies can use this technology to : streamline operations involved within project inspection. This research, conducted in two phases, identified : opportunities for proces...

Automated Array Assembly, Phase 2. Quarterly technical progress report, April-June 1979

Energy Technology Data Exchange (ETDEWEB)

Carbajal, B.G.

1979-07-01

The Automated Array Assembly Task, Phase 2 of the Low Cost Solar Array (LSA) Project is a process development task. This contract provides for the fabrication of modules from large area Tandem Junction Cells (TJC). The key activities in this contract effort are (a) Large Area TJC including cell design, process verification and cell fabrication and (b) Tandem Junction Module (TJM) including definition of the cell-module interfaces, substrate fabrication, interconnect fabrication and module assembly. The overall goal is to advance solar cell module process technology to meet the 1986 goal of a production capability of 500 megawatts per year at a cost of less than $500 per peak kilowatt. This contract will focus on the Tandem Junction Module process. During this quarter, effort was focused on design and process verification. The large area TJC design was completed and the design verification was completed. Process variation experiments led to refinements in the baseline TJC process. Formed steel substrates were porcelainized. Cell array assembly techniques using infrared soldering are being checked out. Dummy cell arrays up to 5 cell by 5 cell have been assembled using all backside contacts.

Design of photonic phased array switches using nano electromechanical systems on silicon-on-insulator integration platform

Science.gov (United States)

Hussein, Ali Abdulsattar

This thesis presents an introduction to the design and simulation of a novel class of integrated photonic phased array switch elements. The main objective is to use nano-electromechanical (NEMS) based phase shifters of cascaded under-etched slot nanowires that are compact in size and require a small amount of power to operate them. The structure of the switch elements is organized such that it brings the phase shifting elements to the exterior sides of the photonic circuits. The transition slot couplers, used to interconnect the phase shifters, are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the switch element, which is taken as a ground. Phased array switch elements ranging from 2x2 up to 8x8 multiple-inputs/multiple-outputs (MIMO) are conveniently designed within reasonable footprints native to the current fabrication technologies. Chapter one presents the general layout of the various designs of the switch elements and demonstrates their novel features. This demonstration will show how waveguide disturbances in the interconnecting network from conventional switch elements can be avoided by adopting an innovative design. Some possible applications for the designed switch elements of different sizes and topologies are indicated throughout the chapter. Chapter two presents the design of the multimode interference (MMI) couplers used in the switch elements as splitters, combiners and waveguide crossovers. Simulation data and design methodologies for the multimode couplers of interest are detailed in this chapter. Chapter three presents the design and analysis of the NEMS-operated phase shifters. Both simulations and numerical analysis are utilized in the design of a 0°-180° capable NEMS-operated phase shifter. Additionally, the response of some of the designed photonic phased

Mobile X-ray inspection of light weight materials

International Nuclear Information System (INIS)

Ewert, Uwe; Redmer, Bernhard; Raedel, Christoph; Osterloh, Kurt; Schnars, Ulf; Henrich, Rudolf; Schimmelmann, Olaf; Bavendiek, Klaus; Jahn, Mirko

2008-01-01

Digital detectors such as phosphor imaging plates (IP) and digital detector arrays (DDA) allow radiographic inspection with higher efficiency and improved image quality in comparison to the classic film technique. Mobile X-ray flash tubes are used routinely for veterinarian and security applications. New high sensitive IPs and DDAs enable to apply them for inspection of light materials with low X-ray attenuation as in aluminium, plastics and composites. A versatile computed tomography (CT) system was developed for in situ inspection of large aircraft components under production conditions. A gate based planar computed tomograph was developed and tested for inspection of integrity of the stringer incorporation. Successful test trials were performed to prove the detection rate of cracks in embedded stringers. Honey comb structures of aircrafts have to be inspected for water inclusions during in-service inspections. Thermography is a powerful method for in house inspections when variations in temperature caused e.g. by sunshine can be excluded. A new X-ray diaphragm was developed for mobile back scatter measurements of large components. This method is insensitive to heat alterations in the field and thus can be applied also outdoors. (orig.)

Ultra-Wideband Phased Array for Millimeter-Wave 5G and ISM

Science.gov (United States)

Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

2016-01-01

Growing mobile data consumption has prompted the exploration of the millimeter-wave spectrum for large bandwidth, high speed communications. However, the allocated bands are spread across a wide swath of spectrum: fifth generation mobile architecture (5G): 28, 38, 39, 64-71 GHz, as well as Industrial, Scientific, and Medical bands (ISM): 24 and 60 GHz. Moreover, high gain phased arrays are required to overcome the significant path loss associated with these frequencies. Further, it is necessary to incorporate several of these applications in a single, small size and low cost platform. To this end, we have developed a scanning, Ultra-Wideband (UWB) array which covers all 5G, ISM, and other mm-W bands from 24-72 GHz. Critically, this is accomplished using mass-production Printed Circuit Board (PCB) fabrication.

Power and phase monitoring system for the lower hybrid phased array heating system on ATC machine

International Nuclear Information System (INIS)

Reed, B.W.

1975-01-01

A four waveguide phased array slow wave structure has been constructed to couple microwave energy into plasma in the ATC Tokamac at Princeton. Theory has indicated that the coupling of power into the plasma column is a strong function of the imposed fourier spectrum at the antenna aperture. To optimize heating, and to verify theoretical results, a precision amplitude and phase monitoring system has been designed and constructed. The system data output is routed to an IBM 1800 computer where the fourier spectrum in n/sub parallel/ space is computed for discrete increments of time during an RF pulse. Computer output data is used to update the adjustment of transmission line parameters in between pulses

New approach for location of continuously emitting acoustic emission sources by phase-controlled probe arrays

International Nuclear Information System (INIS)

Hoeller, P.; Klein, M.; Waschkies, E.; Deuster, G.

1991-01-01

Usually burst-like acoustic emission (AE) is localized by triangulation. For continuous AE, e.g. from leakages, this method is not feasible. Therefore a new method for localization of continuous AE has been developed. It is based on a phase-controlled probe array which consists of many single sensor elements. The AE signals received by the different sensor elements are delayed according to their time-of-flight differences from the source to the single elements of the receiver array. By choosing special combinations of time differences between the array elements the directivity pattern of the sensitivity of the array can be changed, e.g. rotated in the plane of a large plate. Thus, the source direction can be determined by one array. Some preliminary experiments with an artificial noise source, positioned on a large steel plate, have been performed and have demonstrated the feasibility of this approach. (orig.)

Optimizing pre-service inspection data

International Nuclear Information System (INIS)

Mullins, L.E.; Harrison, J.M.

1986-01-01

The phenomenon of intergranular stress corrosion cracking (IGSCC) in nuclear power plant piping systems has been the single biggest factor in an evolution that has changed and continues to change in-service inspection practices and philosophy throughout the industry. In-service inspection has been found to deal with several distinct phases of the problem. At the onset, existing technology was demonstrated to be unable to detect IGSCC adequately. This inability to detect IGSCC was soon overcome. However, it immediately pointed out the difficulties associated with the discrimination between IGSCC and other harmless metallurgical conditions. On the heels of detection and discrimination came problems associated with determining crack size and the monitoring of overlayed flaws. A wealth of information has been written on all phases of IGSCC; however, one particular aspect has as of yet seen little attention. With an increasing number of plants choosing to replace flawed pipe, the pre-service inspection of the replaced piping demands increased attention. The lessons learned through inspection for IGSCC need again to be applied to the replacement piping. Through increased attention at installation, many of the difficulties associated with proper inservice inspection may be reduced or eliminated, thereby realizing an economy in outage scheduling, personnel exposure, and, overall, a more reliable in-service examination

Development and Calibration of a Field-Deployable Microphone Phased Array for Propulsion and Airframe Noise Flyover Measurements

Science.gov (United States)

Humphreys, William M., Jr.; Lockard, David P.; Khorrami, Mehdi R.; Culliton, William G.; McSwain, Robert G.; Ravetta, Patricio A.; Johns, Zachary

2016-01-01

A new aeroacoustic measurement capability has been developed consisting of a large channelcount, field-deployable microphone phased array suitable for airframe noise flyover measurements for a range of aircraft types and scales. The array incorporates up to 185 hardened, weather-resistant sensors suitable for outdoor use. A custom 4-mA current loop receiver circuit with temperature compensation was developed to power the sensors over extended cable lengths with minimal degradation of the signal to noise ratio and frequency response. Extensive laboratory calibrations and environmental testing of the sensors were conducted to verify the design's performance specifications. A compact data system combining sensor power, signal conditioning, and digitization was assembled for use with the array. Complementing the data system is a robust analysis system capable of near real-time presentation of beamformed and deconvolved contour plots and integrated spectra obtained from array data acquired during flyover passes. Additional instrumentation systems needed to process the array data were also assembled. These include a commercial weather station and a video monitoring / recording system. A detailed mock-up of the instrumentation suite (phased array, weather station, and data processor) was performed in the NASA Langley Acoustic Development Laboratory to vet the system performance. The first deployment of the system occurred at Finnegan Airfield at Fort A.P. Hill where the array was utilized to measure the vehicle noise from a number of sUAS (small Unmanned Aerial System) aircraft. A unique in-situ calibration method for the array microphones using a hovering aerial sound source was attempted for the first time during the deployment.

Design and characterization of a laterally mounted phased-array transducer breast-specific MRgHIFU device with integrated 11-channel receiver array.

Science.gov (United States)

Payne, A; Merrill, R; Minalga, E; Vyas, U; de Bever, J; Todd, N; Hadley, R; Dumont, E; Neumayer, L; Christensen, D; Roemer, R; Parker, D

2012-03-01

This work presents the design and preliminary evaluation of a new laterally mounted phased-array MRI-guided high-intensity focused ultrasound (MRgHIFU) system with an integrated 11-channel phased-array radio frequency (RF) coil intended for breast cancer treatment. The design goals for the system included the ability to treat the majority of tumor locations, to increase the MR image's signal-to-noise ratio (SNR) throughout the treatment volume and to provide adequate comfort for the patient. In order to treat the majority of the breast volume, the device was designed such that the treated breast is suspended in a 17-cm diameter treatment cylinder. A laterally shooting 1-MHz, 256-element phased-array ultrasound transducer with flexible positioning is mounted outside the treatment cylinder. This configuration achieves a reduced water volume to minimize RF coil loading effects, to position the coils closer to the breast for increased signal sensitivity, and to reduce the MR image noise associated with using water as the coupling fluid. This design uses an 11-channel phased-array RF coil that is placed on the outer surface of the cylinder surrounding the breast. Mechanical positioning of the transducer and electronic steering of the focal spot enable placement of the ultrasound focus at arbitrary locations throughout the suspended breast. The treatment platform allows the patient to lie prone in a face-down position. The system was tested for comfort with 18 normal volunteers and SNR capabilities in one normal volunteer and for heating accuracy and stability in homogeneous phantom and inhomogeneous ex vivo porcine tissue. There was a 61% increase in mean relative SNR achieved in a homogeneous phantom using the 11-channel RF coil when compared to using only a single-loop coil around the chest wall. The repeatability of the system's energy delivery in a single location was excellent, with less than 3% variability between repeated temperature measurements at the same

National Dam Safety Program. Lakeview Estates Dam (MO 11004), Mississippi - Kaskaskia - St. Louis Basin, Warren County, Missouri. Phase I Inspection Report.

Science.gov (United States)

1979-09-01

ificatiozh Distributon/ Availabilit oe LAKEVIEW ESTATES DAM WARREN COUNTY, MISSOURI MISSOURI INVENTORY NO. 11004 PHASE I INSPECTION REPORT NATIONAL DAM SAFETY...and *impounds less than 1,000 acre-feet of water . Our inspection and evaluation indicates that the spill- way of Lakeview Estates Dam does not meet...not be measured because of high reservoir level, scalloping near the crest and a berm just under the water surface. Limestone riprap in sizes from sand

The Implications of Encoder/Modulator/ Phased Array Designs for Future Broadband LEO Communications

Science.gov (United States)

Vanderaar, Mark; Jensen, Chris A.; Terry, John D.

1997-01-01

In this paper we summarize the effects of modulation and channel coding on the design of wide angle scan, broadband, phased army antennas. In the paper we perform several trade studies. First, we investigate the amplifier back-off requirement as a function of variability of modulation envelope. Specifically, we contrast constant and non-constant envelope modulations, as well as single and multiple carrier schemes. Additionally, we address the issues an(f concerns of using pulse shaping filters with the above modulation types. Second, we quantify the effects of beam steering on the quality of data, recovery using selected modulation techniques. In particular, we show that the frequency response of the array introduces intersymbol interference for broadband signals and that the mode of operation for the beam steering controller may introduce additional burst or random errors. Finally, we show that the encoder/modulator design must be performed in conjunction with the phased array antenna design.

Contribution to the development and the modelling of an ultrasonic conformable phased array transducer for the contact inspection of 3D complex geometry components; Contribution au developpement et a la modelisation d'un traducteur ultrasonore multielements conformable pour l'inspection au contact de composants a geometrie complexe 3D

Energy Technology Data Exchange (ETDEWEB)

Guedes, O

2005-04-15

With the difficulties encountered for the exploration of complex shape surfaces, particularly in nuclear industry, the ultrasonic conformable phased array transducer allows a non destructive evaluation of parts with 3D complex parts. For this, one can use the Smart Contact Transducer principle to generate an ultrasonic field by adaptive dynamic focalisation, with a matrix array composed of independent elements moulded in a soft resin. This work deals with the electro-acoustic conception, with the realization of such a prototype and with the study of it's mechanical and acoustic behaviour. The array design is defined using a radiation model adapted to the simulation of contact sources on a free surface. Once one have defined the shape of the radiating elements, a vibratory analysis using finite elements method allows the determination of the emitting structure with 1-3 piezocomposite, witch leads to the realization of emitting-receiving elements. With the measurement of the field transmitted by such elements, we deduced new hypothesis to change the model of radiation. Thus one can take into account normal and tangential stresses calculated with finite element modelling at the interface between the element and the propagation medium, to use it with the semi-analytical model. Some vibratory phenomena dealing with fluid coupling of contact transducers have been studied, and the prediction of the transverse wave radiation profile have been improved. The last part of this work deals with the realization of the first prototype of the conformable phased array transducer. For this a deformation measuring system have been developed, to determine the position of each element on real time with the displacement of the transducer on complex shape surfaces. With those positions, one can perform the calculation of the a delay law intended for the adaptive dynamic focusing of the desired ultrasonic field. The conformable phased array transducer have been characterized in

Millimeter-wave pseudomorphic HEMT MMIC phased array components for space communications

Science.gov (United States)

Lan, G. L.; Pao, C. K.; Wu, C. S.; Mandolia, G.; Hu, M.; Yuan, S.; Leonard, Regis

1991-01-01

Recent advances in pseudomorphic HEMT MMIC (PMHEMT/MMIC) technology have made it the preferred candidate for high performance millimeter-wave components for phased array applications. This paper describes the development of PMHEMT/MMIC components at Ka-band and V-band. Specifically, the following PMHEMT/MMIC components will be described: power amplifiers at Ka-band; power amplifiers at V-band; and four-bit phase shifters at V-band. For the Ka-band amplifier, 125 mW output power with 5.5 dB gain and 21 percent power added efficiency at 2 dB compression point has been achieved. For the V-band amplifier, 112 mW output power with 6 dB gain and 26 percent power added efficiency has been achieved. And, for the V-band phase shifter, four-bit (45 deg steps) phase shifters with less than 8 dB insertion loss from 61 GHz to 63 GHz will be described.

A novel, flat, electronically-steered phased array transducer for tissue ablation: preliminary results

International Nuclear Information System (INIS)

Ellens, Nicholas P K; Lucht, Benjamin B C; Gunaseelan, Samuel T; Hudson, John M; Hynynen, Kullervo H

2015-01-01

Flat, λ/2-spaced phased arrays for therapeutic ultrasound were examined in silico and in vitro. All arrays were made by combining modules made of 64 square elements with 1.5 mm inter-element spacing along both major axes. The arrays were designed to accommodate integrated, co-aligned diagnostic transducers for targeting and monitoring. Six arrays of 1024 elements (16 modules) and four arrays of 6144 elements (96 modules) were modelled and compared according to metrics such as peak pressure amplitude, focal size, ability to be electronically-steered far off-axis and grating lobe amplitude. Two 1024 element prototypes were built and measured in vitro, producing over 100 W of acoustic power. In both cases, the simulation model of the pressure amplitude field was in good agreement with values measured by hydrophone. Using one of the arrays, it was shown that the peak pressure amplitude dropped by only 24% and 25% of the on-axis peak pressure amplitude when steered to the edge of the array (40 mm) at depths of 30 mm and 50 mm. For the 6144 element arrays studied in in silico only, similarly high steerability was found: even when steered 100 mm off-axis, the pressure amplitude decrease at the focus was less than 20%, while the maximum pressure grating lobe was only 20%. Thermal simulations indicate that the modules produce more than enough acoustic power to perform rapid ablations at physiologically relevant depths and steering angles. Arrays such as proposed and tested in this study have enormous potential: their high electronic steerability suggests that they will be able to perform ablations of large volumes without the need for any mechanical translation. (paper)

Phased Arrays 1985 Symposium - Proceedings

Science.gov (United States)

1985-08-01

anjl with an1 au~ U lar fy b)eanir. ( mice the 1311 0 ,0 - (a ) ,[ -40.0. -80𔃺 , -90.0 -45.0 0𔃺 45.0 90.0 ANGLE FROM BROADSIDE (DEGREES) aii ia -40,0...Electronic Scanning", RADC-TR-83-128, Dec. 1983. AL) A138808 222 m " ; . . . • " - " - . . . . -" ARRAYS OF COAXIALIY-FED MONOPOLE ELEMENTS IN A PARALLEL...Research Institute Hanscom AFB, MA 01731 Farmingdale, NY 11735 AB ST RAC U Arrays of coaxially-fed monopoles radiating into a parallel plate region

Massively parallel E-beam inspection: enabling next-generation patterned defect inspection for wafer and mask manufacturing

Science.gov (United States)

Malloy, Matt; Thiel, Brad; Bunday, Benjamin D.; Wurm, Stefan; Mukhtar, Maseeh; Quoi, Kathy; Kemen, Thomas; Zeidler, Dirk; Eberle, Anna Lena; Garbowski, Tomasz; Dellemann, Gregor; Peters, Jan Hendrik

2015-03-01

SEMATECH aims to identify and enable disruptive technologies to meet the ever-increasing demands of semiconductor high volume manufacturing (HVM). As such, a program was initiated in 2012 focused on high-speed e-beam defect inspection as a complement, and eventual successor, to bright field optical patterned defect inspection [1]. The primary goal is to enable a new technology to overcome the key gaps that are limiting modern day inspection in the fab; primarily, throughput and sensitivity to detect ultra-small critical defects. The program specifically targets revolutionary solutions based on massively parallel e-beam technologies, as opposed to incremental improvements to existing e-beam and optical inspection platforms. Wafer inspection is the primary target, but attention is also being paid to next generation mask inspection. During the first phase of the multi-year program multiple technologies were reviewed, a down-selection was made to the top candidates, and evaluations began on proof of concept systems. A champion technology has been selected and as of late 2014 the program has begun to move into the core technology maturation phase in order to enable eventual commercialization of an HVM system. Performance data from early proof of concept systems will be shown along with roadmaps to achieving HVM performance. SEMATECH's vision for moving from early-stage development to commercialization will be shown, including plans for development with industry leading technology providers.

Timed arrays wideband and time varying antenna arrays

CERN Document Server

Haupt, Randy L

2015-01-01

Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

32-channel 3 Tesla receive-only phased-array head coil with soccer-ball element geometry.

Science.gov (United States)

Wiggins, G C; Triantafyllou, C; Potthast, A; Reykowski, A; Nittka, M; Wald, L L

2006-07-01

A 32-channel 3T receive-only phased-array head coil was developed for human brain imaging. The helmet-shaped array was designed to closely fit the head with individual overlapping circular elements arranged in patterns of hexagonal and pentagonal symmetry similar to that of a soccer ball. The signal-to-noise ratio (SNR) and noise amplification (g-factor) in accelerated imaging applications were quantitatively evaluated in phantom and human images and compared with commercially available head coils. The 32-channel coil showed SNR gains of up to 3.5-fold in the cortex and 1.4-fold in the corpus callosum compared to a (larger) commercial eight-channel head coil. The experimentally measured g-factor performance of the helmet array showed significant improvement compared to the eight-channel array (peak g-factor 59% and 26% of the eight-channel values for four- and fivefold acceleration). The performance of the arrays is demonstrated in high-resolution and highly accelerated brain images. Copyright (c) 2006 Wiley-Liss, Inc.

Evolution of the Ultrasonic Inspection of Heavy Rotor Forgings Over the Last Decades

Science.gov (United States)

Zimmer, A.; Vrana, J.; Meiser, J.; Maximini, W.; Blaes, N.

2010-02-01

All types of heavy forgings that are used in energy machine industry, rotor shafts as well as discs, retaining rings or tie bolts are subject to extensive nondestructive inspections before they are delivered to the customer. Due to the availability of the parts in simple shapes, these forgings are very well suited for full volmetric inspections using ultrasound. In the beginning, these inspections were carried out manually, using straight beam probes and analogue equipment. Higher requirements in reliability, efficiency, safety and power output in the machines have lead to higher requirements for the ultrasonic inspection in the form of more scanning directions, higher sensitivity demands and improved documentation means. This and the increasing use of high alloy materials for ever growing parts, increase the need for more and more sophisticated methods for testing the forgings. Angle scans and sizing technologies like DGS have been implemented, and for more than 15 years now, mechanized and automated inspections have gained importance since they allow better documentation as well as easier evaluation of the recorded data using different views (B- C- or D-Scans), projections or tomography views. The latest major development has been the availability of phased array probes to increase the flexibility of the inspection systems. Many results of the ongoing research in ultrasonic's have not been implemented yet. Today's availability of fast computers, large and fast data storages allows saving RF inspection data and applying sophisticated signal processing methods. For example linear diffraction tomography methods like SAFT offer tools for 3D reconstruction of inspection data, simplifying sizing and locating of defects as well as for improving signal to noise ratios. While such methods are already applied in medical ultrasonic's, they are still to be implemented in the steel industry. This paper describes the development of the ultrasonic inspection of heavy forgings

Numerical Analysis of Ultrasonic Beam Profile Due to the Change of the Number of Piezoelectric Elements for Phased Array Transducer

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun

1999-01-01

A phased array is a multi-element piezoelectric device whose elements are individually excited by electric pulses at programmed delay time. One of the advantages of using phased array in nondestructive evaluation (NDE) application over conventional ultrasonic transducers is their great maneuverability of ultrasonic beam. There are some parameters such as the number and the size of the piezoelectric elements and the inter-element spacing of the elements to design phased array transducer. In this study, the characteristic of ultrasonic beam for phased array transducer due to the variation of the number of elements has been simulated for ultrasonic SH-wave on the basis of Huygen's principle. Ultrasonic beam directivity and focusing due to the change of time delay of each element were discussed due to the change of the number of piezoelectric elements. It was found that ultrasonic beam was much more spreaded and hence its sound pressure was decreased as steering angle of ultrasonic beam was increased. In addition, the ability of ultrasonic bean focusing decreased gradually with the increase of focal length at the same piezoelectric elements. However, the ability of beam focusing was improved as the number of consisting elements was increased

Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes: Flaw detection and characterization [Phase 1

International Nuclear Information System (INIS)

2006-05-01

Nuclear power plants with heavy water reactors (HWRs) comprise nine percent of today's operating nuclear units, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems are an important factor in assuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Programme (CRP) on Inter-comparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the frame of the IAEA Department of Nuclear Energy's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of the IAEA's project on advanced technologies for HWRs. The objective of the CRP was to inter-compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP, participants have investigated the capability of different techniques to detect and characterize flaws. During the second phase of this CRP, participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in Zirconium alloys. The intent was to identify the most effective pressure tube inspection and diagnostic methods, and to identify further development needs. The organizations that have participated in this CRP are: - The Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL); Chalk River Laboratories (CRL), Canada; - The Research Institute of Nuclear Power Operations (RINPO), China National Nuclear Corporation (CNNC), China; - Bhabha Atomic Research Centre (BARC), India; - The Korea Electric Power Research Institute (KEPRI), Republic of Korea; - The Korea Atomic Energy

Real-time 3D imaging methods using 2D phased arrays based on synthetic focusing techniques.

Science.gov (United States)

Kim, Jung-Jun; Song, Tai-Kyong

2008-07-01

A fast 3D ultrasound imaging technique using a 2D phased array transducer based on the synthetic focusing method for nondestructive testing or medical imaging is proposed. In the proposed method, each column of a 2D array is fired successively to produce transverse fan beams focused at a fixed depth along a given longitudinal direction and the resulting pulse echoes are received at all elements of a 2D array used. After firing all column arrays, a frame of high-resolution image along a given longitudinal direction is obtained with dynamic focusing employed in the longitudinal direction on receive and in the transverse direction on both transmit and receive. The volume rate of the proposed method can be increased much higher than that of the conventional 2D array imaging by employing an efficient sparse array technique. A simple modification to the proposed method can further increase the volume scan rate significantly. The proposed methods are verified through computer simulations.

The structure of single-phase turbulent flows through closely spaced rod arrays

International Nuclear Information System (INIS)

Hooper, J.D.; Rehme, K.

1983-02-01

The axial and azimuthal turbulence intensity in the rod gap region has been shown, for developed single-phase turbulent flow through parallel rod arrays, to strongly increase with decreasing rod spacing. Two array geometries are reported, one constructed from a rectangular cross-section duct containing four rods and spaced at five p/d or w/d ratios. The second test section, constructed from six rods set in a regular square-pitch array, represented the interior flow region of a large array. The mean axial velocity, wall shear stress variation and axial pressure distribution were measured, together with hot-wire anemometer measurements of the Reynolds stresses. No significant non-zero secondary flow components were detected, using techniques capable of resolving secondary flow velocities to 1% of the local axial velocity. For the lowest p/d ratio of 1.036, cross-correlation measurements showed the presence of an energetic periodic azimuthal turbulent velocity component, correlated over a significant part of the flow area. The negligible contribution of secondary flows to the axial momentum balance, and the large azimuthal turbulent velocity component in the rod gap area, suggest a different mechanism than Reynolds stress gradient driven secondary flows for the turbulent transport process in the rod gap. (orig.) [de

Development of Infrared Phase Closure Capability in the Infrared-Optical Telescope Array (IOTA)

Science.gov (United States)

Traub, Wesley A.

2002-01-01

We completed all major fabrication and testing for the third telescope and phase-closure operation at the Infrared-Optical Telescope Array (IOTA) during this period. In particular we successfully tested the phase-closure operation, using a laboratory light source illuminating the full delay-line optical paths, and using an integrated-optic beam combiner coupled to our Picnic-detector camera. This demonstration is an important and near-final milestone achievement. As of this writing, however, several tasks yet remain, owing to development snags and weather, so the final proof of success, phase-closure observation of a star, is now expected to occur in early 2002, soon after this report has been submitted.

Lietuvos Dujos. Inspection of pipeline - Phase 2. Final report. Cathodic protection

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-01

Inspection of pipeline - phase 2 included the following activities: Task 1: On-site training with CP survey equipment combined with a check of CP installations on a pipeline section. Task 2: On-site training with CP survey equipment after remedial work has been done, based on the recommendations given in the task 1 report. Task 3. Assistance to Lietuvos Dujos preparation of a CP survey report. Guidance in how results can be evaluated and main findings reported will be given. Task 4: Assistance to Lietuvos Dujos for installation of two CP stations with anodebed. This final report presents the results of task 2, 3 and 4. Only the major results of task 1 are described, thus the results of task 1 is described in details in the Interim Report, September 1996. (au)

An Ultra-Wideband Millimeter-Wave Phased Array

Science.gov (United States)

Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

2016-01-01

Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

A 1372-element Large Scale Hemispherical Ultrasound Phased Array Transducer for Noninvasive Transcranial Therapy

International Nuclear Information System (INIS)

Song, Junho; Hynynen, Kullervo

2009-01-01

Noninvasive transcranial therapy using high intensity focused ultrasound transducers has attracted high interest as a promising new modality for the treatments of brain related diseases. We describe the development of a 1372 element large scale hemispherical ultrasound phased array transducer operating at a resonant frequency of 306 kHz. The hemispherical array has a diameter of 31 cm and a 15.5 cm radius of curvature. It is constructed with piezoelectric (PZT-4) tube elements of a 10 mm in diameter, 6 mm in length and 1.4 mm wall thickness. Each element is quasi-air backed by attaching a cork-rubber membrane on the back of the element. The acoustic efficiency of the element is determined to be approximately 50%. The large number of the elements delivers high power ultrasound and offers better beam steering and focusing capability. Comparisons of sound pressure-squared field measurements with theoretical calculations in water show that the array provides good beam steering and tight focusing capability over an efficient volume of approximately 100x100x80 mm 3 with nominal focal spot size of approximately 2.3 mm in diameter at -6 dB. We also present its beam steering and focusing capability through an ex vivo human skull by measuring pressure-squared amplitude after phase corrections. These measurements show the same efficient volume range and focal spot sizes at -6 dB as the ones in water without the skull present. These results indicate that the array is sufficient for use in noninvasive transcranial ultrasound therapy.

Using phase information to enhance speckle noise reduction in the ultrasonic NDE of coarse grain materials

Energy Technology Data Exchange (ETDEWEB)

Lardner, Timothy; Gachagan, Anthony [Centre for Ultrasonic Engineering, University of Strathclyde, Glasgow, G1 1XW (United Kingdom); Li, Minghui [School of Engineering, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

2014-02-18

Materials with a coarse grain structure are becoming increasingly prevalent in industry due to their resilience to stress and corrosion. These materials are difficult to inspect with ultrasound because reflections from the grains lead to high noise levels which hinder the echoes of interest. Spatially Averaged Sub-Aperture Correlation Imaging (SASACI) is an advanced array beamforming technique that uses the cross-correlation between images from array sub-apertures to generate an image weighting matrix, in order to reduce noise levels. This paper presents a method inspired by SASACI to further improve imaging using phase information to refine focusing and reduce noise. A-scans from adjacent array elements are cross-correlated using both signal amplitude and phase to refine delay laws and minimize phase aberration. The phase-based and amplitude-based corrected images are used as inputs to a two-dimensional cross-correlation algorithm that will output a weighting matrix that can be applied to any conventional image. This approach was validated experimentally using a 5MHz array a coarse grained Inconel 625 step wedge, and compared to the Total Focusing Method (TFM). Initial results have seen SNR improvements of over 20dB compared to TFM, and a resolution that is much higher.

Using phase information to enhance speckle noise reduction in the ultrasonic NDE of coarse grain materials

Science.gov (United States)

Lardner, Timothy; Li, Minghui; Gachagan, Anthony

2014-02-01

Materials with a coarse grain structure are becoming increasingly prevalent in industry due to their resilience to stress and corrosion. These materials are difficult to inspect with ultrasound because reflections from the grains lead to high noise levels which hinder the echoes of interest. Spatially Averaged Sub-Aperture Correlation Imaging (SASACI) is an advanced array beamforming technique that uses the cross-correlation between images from array sub-apertures to generate an image weighting matrix, in order to reduce noise levels. This paper presents a method inspired by SASACI to further improve imaging using phase information to refine focusing and reduce noise. A-scans from adjacent array elements are cross-correlated using both signal amplitude and phase to refine delay laws and minimize phase aberration. The phase-based and amplitude-based corrected images are used as inputs to a two-dimensional cross-correlation algorithm that will output a weighting matrix that can be applied to any conventional image. This approach was validated experimentally using a 5MHz array a coarse grained Inconel 625 step wedge, and compared to the Total Focusing Method (TFM). Initial results have seen SNR improvements of over 20dB compared to TFM, and a resolution that is much higher.

Small-angle tomography algorithm for transmission inspection of acoustic linear array

Directory of Open Access Journals (Sweden)

Soldatov Alexey

2016-01-01

Full Text Available The paper describes the algorithm of reconstruction of tomographic image used in the through-transition method in a small angle sounding of acoustic linear arrays and the results of practical application of the proposed algorithm. In alternate probing of each element of emitting array and simultaneous reception of all elements of the receiving array is a collection of shadow images of the testing zone. The testing zone is divided into small local areas and using the collection of shadow images computed matrix normalized transmission coefficients for each of the small local area. Tomographic image control zone is obtained by submitting the resulting matrix of normalized transmission coefficients in grayscale or colors.

Application of phased array technology for identification of low frequency noise sources

Energy Technology Data Exchange (ETDEWEB)

Hugo E. Camargo; Patricio A. Ravetta; Ricardo A. Burdisso; Adam K. Smith [NIOSH (United States)

2009-12-15

A study conducted by the National Institute for Occupational Safety and Health (NIOSH) revealed that 90% of coal miners have hearing impairment by age 50, compared to only 10% of those not exposed to occupational noise. According to the Mine Safety and Health Administration (MSHA), Continuous Mining Machine (CM) operators account for 30% of workers exposed to noise doses exceeding the Permissible Exposure Level (PEL). In this context, NIOSH is conducting research to identify and control dominant noise sources in CMs. Previous noise source identification was performed using a Bruel & Kjaer (B&K) 1.92-m diameter, 42-microphone phased array. These measurements revealed that the impacts from the conveyor chain onto the tail roller, and the impacts from the conveyor chain onto the upper deck are the dominant noise sources at the tail-section of the CM. The objectives of the work presented in this paper were: (1) To rank the noise radiated by the different sections of the conveyor, and (2) to determine the effect of a urethane-coated tail roller on the noise radiated by the tail-section. This test was conducted using an Acoustical and Vibrations Engineering Consultants (AVEC) 3.5-m diameter, 121-microphone phased array. The results from this new test show that a urethane-coated tail roller yields reductions in the tail-section of 2 to 8 dB in Sound Pressure Level in the frequency range of 1 kHz to 5 kHz. However, integration of the acoustic maps shows that the front-section and mid-section of the conveyor also contain dominant noise sources. Therefore, a urethane-coated tail roller in combination with a chain with urethane-coated flights that reduces the noise sources in the front and mid sections of the conveyor is required to yield a significant noise reduction on the CM operator's overall exposure. These results show the applicability of phased array technology for low frequency noise source identification.

Dualband MW/LW Strained Layer Superlattice Focal Plane Arrays for Satellite-Based Wildfire Detection, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Infrared focal plane arrays (FPAs) based on Type-II strained layer superlattice (SLS) photodiodes have recently experienced significant advances. In Phase I we...

Multi-colorimetric sensor array for detection of explosives in gas and liquid phase

DEFF Research Database (Denmark)

Kostesha, Natalie; Alstrøm, Tommy Sonne; Johnsen, C.

2011-01-01

In the framework of the research project "Xsense" at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT, TATP, HMX, RDX and identification of reagents needed for making homemade explosives. The tec......In the framework of the research project "Xsense" at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT, TATP, HMX, RDX and identification of reagents needed for making homemade explosives...... to the analytes creates a color difference map which gives a unique fingerprint for each explosive and VOCs. Such sensing technology can be used for screening relevant explosives in a complex background as well as to distinguish mixtures of volatile organic compounds distributed in gas and liquid phases....... This sensor array is inexpensive, and can potentially be produced as single use disposable....

System and method for online inspection of turbines using an optical tube with broadspectrum mirrors

Science.gov (United States)

Baleine, Erwan

2015-12-22

An optical inspection system for nondestructive internal visual inspection and non-contact infra-red (IR) temperature monitoring of an online, operating power generation turbine. The optical inspection system includes an optical tube having a viewing port, at least one reflective mirror or a mirror array having a reflectivity spectral range from 550 nm to 20 .mu.m, and capable of continuous operation at temperatures greater than 932 degrees Fahrenheit (500 degrees Celsius), and a transparent window with high transmission within the same spectral range mounted distal the viewing port. The same optical mirror array may be used to measure selectively surface temperature of metal turbine blades in the near IR range (approximately 1 .mu.m wavelength) and of thermal barrier coated turbine blades in the long IR range (approximately 10 .mu.m wavelength).

Ambiguity resolving based on cosine property of phase differences for 3D source localization with uniform circular array

Science.gov (United States)

Chen, Xin; Wang, Shuhong; Liu, Zhen; Wei, Xizhang

2017-07-01

Localization of a source whose half-wavelength is smaller than the array aperture would suffer from serious phase ambiguity problem, which also appears in recently proposed phase-based algorithms. In this paper, by using the centro-symmetry of fixed uniform circular array (UCA) with even number of sensors, the source's angles and range can be decoupled and a novel ambiguity resolving approach is addressed for phase-based algorithms of source's 3-D localization (azimuth angle, elevation angle, and range). In the proposed method, by using the cosine property of unambiguous phase differences, ambiguity searching and actual-value matching are first employed to obtain actual phase differences and corresponding source's angles. Then, the unambiguous angles are utilized to estimate the source's range based on a one dimension multiple signal classification (1-D MUSIC) estimator. Finally, simulation experiments investigate the influence of step size in search and SNR on performance of ambiguity resolution and demonstrate the satisfactory estimation performance of the proposed method.

Synthesis and photoluminescence of a full zinc blende phase ZnO nanorod array

International Nuclear Information System (INIS)

Zhou Shaomin; Gong Hechun; Zhang Bin; Du Zuliang; Zhang Xingtang; Wu Sixin

2008-01-01

A single-crystalline ZnO nanorod array with rectangular cross-sections has been synthesized, in which the as-obtained products are a complete metastable zinc blende (ZB) phase. X-ray powder diffraction, electron microscopy, and elemental maps have been used to show that the ZB-ZnO samples have a lattice constant a = 4.580 A, and are free from contamination by hexagonal wurtzite (HW) ZnO. Based on our experimental data, the associated growth mechanism is tentatively suggested. In addition, the photoluminescence (PL) spectrum (about 400 nm (3.1 eV)) of the as-fabricated ZB-ZnO products was detected; this is the first experimental report of the optical properties of ZB-ZnO nanorod arrays

Coupled-oscillator based active-array antennas

CERN Document Server

Pogorzelski, Ronald J

2012-01-01

Describing an innovative approach to phased-array control in antenna design This book explores in detail phased-array antennas that use coupled-oscillator arrays, an arrangement featuring a remarkably simple beam steering control system and a major reduction in complexity compared with traditional methods of phased-array control. It brings together in one convenient, self-contained volume the many salient research results obtained over the past ten to fifteen years in laboratories around the world, including the California Institute of Technology's Jet Propulsion Laboratory.

Two-dimensional analytic modeling of acoustic diffraction for ultrasonic beam steering by phased array transducers.

Science.gov (United States)

Wang, Tiansi; Zhang, Chong; Aleksov, Aleksandar; Salama, Islam; Kar, Aravinda

2017-04-01

Phased array ultrasonic transducers enable modulating the focal position of the acoustic waves, and this capability is utilized in many applications, such as medical imaging and non-destructive testing. This type of transducers also provides a mechanism to generate tilted wavefronts in acousto-optic deflectors to deflect laser beams for high precision advanced laser material processing. In this paper, a theoretical model is presented for the diffraction of ultrasonic waves emitted by several phased array transducers into an acousto-optic medium such as TeO 2 crystal. A simple analytic expression is obtained for the distribution of the ultrasonic displacement field in the crystal. The model prediction is found to be in good agreement with the results of a numerical model that is based on a non-paraxial multi-Gaussian beam (NMGB) model. Published by Elsevier B.V.

A Planar Switchable 3-D-Coverage Phased Array Antenna and Its User Effects for 28-GHz Mobile Terminal Applications

DEFF Research Database (Denmark)

Zhang, Shuai; Chen, Xiaoming; Syrytsin, Igor A.

2017-01-01

This paper introduces a planar switchable 3D-coverage phased array for 28 GHz mobile terminal applications. In order to realize 3D-coverage beam scan with a simple planar array, chassis surface waves are efficiently excited and controlled by three identical slot subarrays. Three subarrays switch...

Microwave monolithic integrated circuit development for future spaceborne phased array antennas

Science.gov (United States)

Anzic, G.; Kascak, T. J.; Downey, A. N.; Liu, D. C.; Connolly, D. J.

1984-01-01

The development of fully monolithic gallium arsenide (GaAs) receive and transmit modules suitable for phased array antenna applications in the 30/20 gigahertz bands is presented. Specifications and various design approaches to achieve the design goals are described. Initial design and performance of submodules and associated active and passive components are presented. A tradeoff study summary is presented, highlighting the advantages of a distributed amplifier approach compared to the conventional single power source designs. Previously announced in STAR as N84-13399

Microwave monolithic integrated circuit development for future spaceborne phased array antennas

Science.gov (United States)

Anzic, G.; Kascak, T. J.; Downey, A. N.; Liu, D. C.; Connolly, D. J.

The development of fully monolithic gallium arsenide (GaAs) receive and transmit modules suitable for phased array antenna applications in the 30/20 gigahertz bands is presented. Specifications and various design approaches to achieve the design goals are described. Initial design and performance of submodules and associated active and passive components are presented. A tradeoff study summary is presented, highlighting the advantages of a distributed amplifier approach compared to the conventional single power source designs. Previously announced in STAR as N84-13399

A new omnidirectional shear horizontal wave transducer using face-shear (d24) piezoelectric ring array.

Science.gov (United States)

Miao, Hongchen; Huan, Qiang; Wang, Qiangzhong; Li, Faxin

2017-02-01

The non-dispersive fundamental shear horizontal (SH 0 ) wave in plate-like structures is of practical importance in non-destructive testing (NDT) and structural health monitoring (SHM). Theoretically, an omnidirectional SH 0 transducer phased array system can be used to inspect defects in a large plate in the similar manner to the phased array transducers used in medical B-scan ultrasonics. However, very few omnidirectional SH 0 transducers have been proposed so far. In this work, an omnidirectional SH 0 wave piezoelectric transducer (OSH-PT) was proposed, which consists of a ring array of twelve face-shear (d 24 ) trapezoidal PZT elements. Each PZT element can produce face-shear deformation under applied voltage, resulting in circumferential shear deformation in the OSH-PT and omnidirectional SH 0 waves in the hosting plate. Both finite element simulations and experiments were conducted to examine the performance of the proposed OSH-PT. Experimental testing shows that the OSH-PT exhibits good omnidirectional properties, no matter it is used as a SH 0 wave transmitter or a SH 0 wave receiver. This work may greatly promote the applications of SH 0 waves in NDT and SHM. Copyright © 2016 Elsevier B.V. All rights reserved.

Design of a K-Band Transmit Phased Array For Low Earth Orbit Satellite Communications

Science.gov (United States)

Watson, Thomas; Miller, Stephen; Kershner, Dennis; Anzic, Godfrey

2000-01-01

The design of a light weight, low cost phased array antenna is presented. Multilayer printed wiring board (PWB) technology is utilized for Radio Frequencies (RF) and DC/Logic manifold distribution. Transmit modules are soldered on one side and patch antenna elements are on the other, allowing the use of automated assembly processes. The 19 GHz antenna has two independently steerable beams, each capable of transferring data at 622 Mbps. A passive, self-contained phase change thermal management system is also presented.

Simulation of a ring resonator-based optical beamformer system for phased array receive antennas

NARCIS (Netherlands)

Tijmes, M.R.; Meijerink, Arjan; Roeloffzen, C.G.H.; Bentum, Marinus Jan

2009-01-01

A new simulator tool is described that can be used in the field of RF photonics. It has been developed on the basis of a broadband, continuously tunable optical beamformer system for phased array receive antennas. The application that is considered in this paper is airborne satellite reception of

A Wearable Transcranial Doppler Ultrasound Phased Array System.

Science.gov (United States)

Pietrangelo, Sabino J; Lee, Hae-Seung; Sodini, Charles G

2018-01-01

 Practical deficiencies related to conventional transcranial Doppler (TCD) sonography have restricted its use and applicability. This work seeks to mitigate several such constraints through the development of a wearable, electronically steered TCD velocimetry system, which enables noninvasive measurement of cerebral blood flow velocity (CBFV) for monitoring applications with limited operator interaction. A highly-compact, discrete prototype system was designed and experimentally validated through flow phantom and preliminary human subject testing. The prototype system incorporates a custom two-dimensional transducer array and multi-channel transceiver electronics, thereby facilitating acoustic beamformation via phased array operation. Electronic steering of acoustic energy enables algorithmic system controls to map Doppler power throughout the tissue volume of interest and localize regions of maximal flow. Multi-focal reception permits dynamic vessel position tracking and simultaneous flow velocimetry over the time-course of monitoring. Experimental flow phantom testing yielded high correlation with concurrent flowmeter recordings across the expected range of physiological flow velocities. Doppler power mapping has been validated in both flow phantom and preliminary human subject testing, resulting in average vessel location mapping times testing. A wearable prototype CBFV measurement system capable of autonomous vessel search and tracking has been presented. Although flow phantom and preliminary human validation show promise, further human subject testing is necessary to compare velocimetry data against existing commercial TCD systems. Additional human subject testing must also verify acceptable vessel search and tracking performance under a variety of subject populations and motion dynamics-such as head movement and ambulation.

Use of a Microphone Phased Array to Determine Noise Sources in a Rocket Plume

Science.gov (United States)

Panda, J.; Mosher, R.

2010-01-01

A 70-element microphone phased array was used to identify noise sources in the plume of a solid rocket motor. An environment chamber was built and other precautions were taken to protect the sensitive condenser microphones from rain, thunderstorms and other environmental elements during prolonged stay in the outdoor test stand. A camera mounted at the center of the array was used to photograph the plume. In the first phase of the study the array was placed in an anechoic chamber for calibration, and validation of the indigenous Matlab(R) based beamform software. It was found that the "advanced" beamform methods, such as CLEAN-SC was partially successful in identifying speaker sources placed closer than the Rayleigh criteria. To participate in the field test all equipments were shipped to NASA Marshal Space Flight Center, where the elements of the array hardware were rebuilt around the test stand. The sensitive amplifiers and the data acquisition hardware were placed in a safe basement, and 100m long cables were used to connect the microphones, Kulites and the camera. The array chamber and the microphones were found to withstand the environmental elements as well as the shaking from the rocket plume generated noise. The beamform map was superimposed on a photo of the rocket plume to readily identify the source distribution. It was found that the plume made an exceptionally long, >30 diameter, noise source over a large frequency range. The shock pattern created spatial modulation of the noise source. Interestingly, the concrete pad of the horizontal test stand was found to be a good acoustic reflector: the beamform map showed two distinct source distributions- the plume and its reflection on the pad. The array was found to be most effective in the frequency range of 2kHz to 10kHz. As expected, the classical beamform method excessively smeared the noise sources at lower frequencies and produced excessive side-lobes at higher frequencies. The "advanced" beamform

Pre-service baseline inspection using x-probe of Oconee replacement steam generators

International Nuclear Information System (INIS)

Addario, M.; Shipp, P.; Davis, K.; Fogal, C.

2003-01-01

The eddy current method has been the industry standard for inspecting steam generator tubing for many years and the level of sophistication of coil technology has continued to evolve during that time. State of the art array probe systems now employ multiple sensitivity zones in the probe to better detect and characterize defects in an efficient manner. Owners and regulators of nuclear power plants are interested in the most effective and efficient inspection possible. The ultimate goal has been to meet or exceed new and existing regulatory and design requirements by maximizing the quantity and quality of eddy current data collected while minimizing both the time needed to perform the inspection and the radiation exposure. The X-Probe is an example of this new eddy current array technology. Qualified to detect all types of known defects in steam generator tubing, the technology is comprised of a system of probe, data acquisition instrumentation, computer and human interface software. Recently, Duke Power, along with Babcock and Wilcox Canada and the system developer R/D Tech, collaborated to implement this technology in a first of a kind full scale pre-service inspection of replacement steam generators for Duke Power's Oconee nuclear generating station at Babcock and Wilcox Canada's Cambridge plant. The discussion in this paper will briefly describe the X-Probe technology, describe the system required to perform the inspection, present the general results of the inspection and finally draw some comparative benefit conclusions for both pre-service and in-service applications. (author)

A Method of Estimating Pressure and Intensity Distributions of Multielement Phased Array High Intensity Focused Ultrasonic Field at Full Power Using a Needle Hydrophone

International Nuclear Information System (INIS)

Yu Ying; Shen Guofeng; Bai Jingfeng; Chen Yazhu

2011-01-01

The pressure and intensity distribution of high intensity focused ultrasound (HIFU) fields at full power are critical for predicting heating patterns and ensuring safety of the therapy. With the limitations of maximum pressure at the hydrophone and damage from cavitation or thermal effects, it is hard to measure pressure and intensity directly when HIFU is at full power. HIFU-phased arrays are usually composed of large numbers of small elements and the sound power radiated from some of them at full power is measureable using a hydrophone, we grouped them based on the limitation of maximum permissible pressure at the hydrophone and the characteristics of the element arrangement in the array. Then sound field measurement of the group was carried out at full power level. Using the acoustic coherence principle, the pressure and intensity distribution of the array at full power level can be calculated from corresponding values from the groups. With this method, computer simulations and sound field measurement of a 65-element concentric distributed phased array was carried out. The simulation results demonstrate theoretically the feasibility of this method. Measurements on the 65-element phased array also verify the effectiveness of this method for estimating the pressure and intensity distribution of phased array at full power level using a needle hydrophone.

Development and field practical performance of smart array probe

International Nuclear Information System (INIS)

Maeda, Kotaro; Shimone, Junri; Akagawa, Junichi; Nagata, Yasuyuki; Harada, Yutaka; Sera, Takehiko; Hirano, Shinro

2011-01-01

In 1999, NEL developed the transmit-receive type ECT array probe for steam generator (SG) tubing, called 'X-probe', in cooperation with foreign firms. Recently NEL has developed the advanced ECT array probe, 'Smart Array Probe', characterized with a significantly improved resolution for circumferential cracks. The doubled channels in the circumferential mode have greatly improved the circumferential resolution of Smart Array Probe. With all the circumferential mode channels on the same circle, there is no need for axial position correction of inspection data. This report describes both the field practical performance and the compliance assessment to a Japanese SG-ECT guideline 'JEAG4208' of Smart Array ECT System, composed of Smart Array Probe, pusher-in-tester 'OMNI-200', and NEL's ECT Analysis System. (author)

Optical Inspection In Hostile Industrial Environments: Single-Sensor VS. Imaging Methods

Science.gov (United States)

Cielo, P.; Dufour, M.; Sokalski, A.

1988-11-01

On-line and unsupervised industrial inspection for quality control and process monitoring is increasingly required in the modern automated factory. Optical techniques are particularly well suited to industrial inspection in hostile environments because of their noncontact nature, fast response time and imaging capabilities. Optical sensors can be used for remote inspection of high temperature products or otherwise inaccessible parts, provided they are in a line-of-sight relation with the sensor. Moreover, optical sensors are much easier to adapt to a variety of part shapes, position or orientation and conveyor speeds as compared to contact-based sensors. This is an important requirement in a flexible automation environment. A number of choices are possible in the design of optical inspection systems. General-purpose two-dimensional (2-D) or three-dimensional (3-D) imaging techniques have advanced very rapidly in the last years thanks to a substantial research effort as well as to the availability of increasingly powerful and affordable hardware and software. Imaging can be realized using 2-D arrays or simpler one-dimensional (1-D) line-array detectors. Alternatively, dedicated single-spot sensors require a smaller amount of data processing and often lead to robust sensors which are particularly appropriate to on-line operation in hostile industrial environments. Many specialists now feel that dedicated sensors or clusters of sensors are often more effective for specific industrial automation and control tasks, at least in the short run. This paper will discuss optomechanical and electro-optical choices with reference to the design of a number of on-line inspection sensors which have been recently developed at our institute. Case studies will include real-time surface roughness evaluation on polymer cables extruded at high speed, surface characterization of hot-rolled or galvanized-steel sheets, temperature evaluation and pinhole detection in aluminum foil, multi

High resolution MR imaging of the hip using pelvic phased-array coil

Energy Technology Data Exchange (ETDEWEB)

Niitsu, Mamoru; Mishima, Hajime; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

1997-01-01

A pelvic phased-array coil was applied to obtain high resolution MR images of the hip. Three-mm-thick fast spin-echo images were obtained in seven hips. Images with a pelvic coil enhanced delineation of acetabular labrum and articular cartilage more clearly than those with a body coil or flexible-surface coil. The use of a pelvic coil in imaging of the hip may be of diagnostic value because of its superior delineation. (author)

Detector correction in large container inspection systems

CERN Document Server