Golay-based total focusing method using a high-frequency, lead-free, flexible ultrasonic array to improve industrial inspections

High frequency (>15 MHz) ultrasound arrays have attracted considerable interest in recent years due to their ability to provide images with enhanced spatial resolution, offering higher sensitivity to smaller defects in materials and structures. Defects can be detected at earlier growth stages as compared to lower frequency counterparts. Conversely, high-frequency sound waves have limited penetration depth that can hinder the inspection of thicker components. Moreover, research into lead-free alternatives to lead zirconate titanate (PZT) is prominent due to the European Union's Restriction of Hazardous Substances (RoHS) regulation. Achieving optimal ultrasound imaging with lead-free materials remains a persistent challenge, given the importance of transducer sensitivity. Here, an advanced approach combining a high-frequency, lead-free, flexible ultrasonic array and Golay-coded excitation to address the limitation in penetration depth in ultrasound imaging, particularly of samples with non-planar surface geometries, is presented.This study employed a commercial 20 MHz 64 element 1 mm pitch lead-free flexible linear ultrasonic array, developed by Novosound Ltd, using Golay-coded excitation to improve the penetration depth and exploit the flexibility for operation on both planar and non-planar components. Golay complementary sequences were designed and employed to excite the array. Pulse compression was realised through the application of a matched filter.A signal-to-noise ratio (SNR) improvement verification study was conducted with the array deployed on a 20 mm thick planar aluminium sample. As anticipated, an increase in SNR was observed as the length of the Golay codes increased, matching the theoretical 3 dB improvement between successive length doubling. Furthermore, the appropriate Golay code length is contingent on the specific demands of the application with respect to acceptable SNR and minimisation of the dead zone to improve near surface inspection capability. The array offers the versatility to adapt to complex surface profiles. A curved test specimen with known defects was next explored. Total focusing method (TFM) images of the sample for both pulse and Golay excitations were obtained and compared. The Golay-based TFM outperformed the standard pulse-based TFM, resulting in an improved imaging penetration depth.The proposed approach, which integrates a RoHS-compliant, flexible array with Golay-coded excitation, has the potential to improve the quality of industrial inspections in terms of efficiency, accuracy, and reliability

Golay-based total focusing method using a high-frequency, lead-free, flexible ultrasonic array to improve industrial inspections

High frequency (>15 MHz) ultrasound arrays have attracted considerable interest in recent years due to their ability to provide images with enhanced spatial resolution, offering higher sensitivity to smaller defects in materials and structures. Defects can be detected at earlier growth stages as compared to lower frequency counterparts. Conversely, high-frequency sound waves have limited penetration depth that can hinder the inspection of thicker components. Moreover, research into lead-free alternatives to lead zirconate titanate (PZT) is prominent due to the European Union's Restriction of Hazardous Substances (RoHS) regulation. Achieving optimal ultrasound imaging with lead-free materials remains a persistent challenge, given the importance of transducer sensitivity. Here, an advanced approach combining a high-frequency, lead-free, flexible ultrasonic array and Golay-coded excitation to address the limitation in penetration depth in ultrasound imaging, particularly of samples with non-planar surface geometries, is presented. This study employed a commercial 20 MHz 64 element 1 mm pitch lead-free flexible linear ultrasonic array, developed by Novosound Ltd, using Golay-coded excitation to improve the penetration depth and exploit the flexibility for operation on both planar and non-planar components. Golay complementary sequences were designed and employed to excite the array. Pulse compression was realised through the application of a matched filter. A signal-to-noise ratio (SNR) improvement verification study was conducted with the array deployed on a 20 mm thick planar aluminium sample. As anticipated, an increase in SNR was observed as the length of the Golay codes increased, matching the theoretical 3 dB improvement between successive length doubling. Furthermore, the appropriate Golay code length is contingent on the specific demands of the application with respect to acceptable SNR and minimisation of the dead zone to improve near surface inspection capability. The array offers the versatility to adapt to complex surface profiles. A curved test specimen with known defects was next explored. Total focusing method (TFM) images of the sample for both pulse and Golay excitations were obtained and compared. The Golay-based TFM outperformed the standard pulse-based TFM, resulting in an improved imaging penetration depth. The proposed approach, which integrates a RoHS-compliant, flexible array with Golay-coded excitation, has the potential to improve the quality of industrial inspections in terms of efficiency, accuracy, and reliability

ILC Reference Design Report Volume 1 - Executive Summary

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization

ILC Reference Design Report Volume 4 - Detectors

This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics.This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics

ILC Reference Design Report Volume 3 - Accelerator

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC

International Linear Collider Reference Design Report Volume 2: PHYSICS AT THE ILC

This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described.This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described