Ring Light Research Articles

Coherent synchrotron radiation instability in low-emittance electron storage rings

High-frequency longitudinal impedances, particularly at wavenumbers k≫1/σz (where σz is the bunch length), can drive microwave instability and potentially limit the performance of modern low-emittance electron storage rings. In such rings, the coherent synchrotron radiation (CSR) emerges as a prominent contributor to these high-frequency impedances. This paper undertakes a systematic investigation into the effects of CSR on electron rings, utilizing the fourth-generation storage ring light source Elettra 2.0 and the low-energy ring of the SuperKEKB e+e− circular collider as illustrative examples. Our work revisits theories of microwave instability driven by CSR impedance, extending the analysis to encompass other high-frequency impedances, such as resistive wall and coherent wiggler radiation. Through instability analysis and numerical simulations conducted on the two aforementioned rings, the study explored the impact of high-frequency impedances and their combined effects with broadband impedances caused by discontinuities in vacuum chambers. Published by the American Physical Society 2024

Quantifying Drosophila melanogaster Eye Phenotypes: A Computational Approach Integrating ilastik and Flynotyper.

The Drosophila melanogaster compound eye is a well-structured and comprehensive array of around 800 ommatidia, exhibiting a symmetrical and hexagonal pattern. This regularity and ease of observation make the Drosophila eye system a powerful tool to model various human neurodegenerative diseases. However, ways of quantifying abnormal phenotypes, such as manual ranking of eye severity scores, have limitations, especially when ranking weak alterations in eye morphology. To overcome these limitations, computational approaches have been developed such as Flynotyper. The use of a ring light allows for better qualitative images accessing the intactness of individual ommatidia. However, these images cannot be analyzed by Flynotyper directly due to shadows on ommatidia introduced by the ring light. Here, we describe an unbiased way to quantify rough eye phenotypes observed in Drosophila disease models by combining two software, ilastik and Flynotyper. By preprocessing the images with ilastik, successful quantification of the rough eye phenotype can be achieved with Flynotyper.

Research on Point Cloud Acquisition and Calibration of Deep Hole Inner Surfaces Based on Collimated Ring Laser Beams.

In this study, a ring light point cloud calibration technique based on collimated laser beams is developed, aiming to reduce errors caused by the position and attitude changes of traditional ring light measurement devices. This article details the generation mechanism of the ring beam and the principle of deep hole measurement. It introduces the collimated beam as a reference, building on traditional ring light measurement devices, to achieve the synchronous acquisition of the ring beam and collimated spot images by an industrial camera. The Steger algorithm is employed to accurately extract the coordinates of the point cloud contours of both the ring beam and the collimated spot. By analyzing the shape and position changes of the collimated spot contour, the spatial position and attitude of the measuring device are precisely determined. This technique is applied to the 3D reconstruction of the inner surface of deep holes, ensuring the accurate restoration of the spatial positional attitude of the ring beam by incorporating the spatial positional attitude parameters of the measuring device to precisely calibrate the cross-sectional point cloud coordinates. Experimental results with ring gauges and deep hole workpieces demonstrate that this technique effectively reduces the percentage of point cloud data outside the tolerance range, and improves the accuracy of the 3D reconstruction model by 6.287%, thereby verifying the accuracy and practicality of this technique.

Development of high-level applications for High Energy Photon Source booster

The High Energy Photon Source (HEPS), is the first fourth-generation storage ring light source being built in the suburb of Beijing, China. The storage ring was designed with the emittance lower than 60 pm.rad with a circumference of 1.36 km and beam energy of 6 GeV. Its injector contains a 500 MeV S-band Linac and a 454 m booster which was designed as an accumulator at the extraction energy. In the energy ramping control design of HEPS booster, the ramping process was programed to be able to stop and stay at any energy between the injection energy and the extraction energy. This feature enables us to conduct energy-dependent machine studies and ramping curve optimization. The beam commissioning of HEPS Linac finished in June, 2023. And the beam commissioning of booster started in the end of July, 2023. In November 17, main target values proposed in the preliminary design report has been reached. The high-level applications (HLAs) are essential tools for beam commissioning. The development of HLAs, which are based on the framework named Python accelerator physics application set (Pyapas), started in the end of 2021. The HEPS physics team spent more than one year to develop and test the HLAs to meet the requirements of beam commissioning of the booster. Thanks to the modular design, the principle based on physical quantities, and the ability of running simulation models online from the Pyapas, the development efficiency and reliability of the HLAs have been greatly improved. In particular, the principle based on physical quantities allows us to control the beam more intuitively.

Comparison of the perceived image quality of intraoral orthodontic photographs taken with DSLR camera and mobile phone camera: A double-blinded prospective study

Clinical orthodontic photography is a vital skill that every orthodontist should master to record the patients’ details and to permit the orthodontist to carefully plan, monitor and execute the treatment. With the advancement of technology, some clinicians opt to take intraoral photographs with their mobile phone rather than DSLR camera. Hence, this study aimed to answer one main question: whether there was any significant difference in the perceived quality image between intraoral photos taken with a mobile phone and a standard DSLR camera. The cameras used were a DSLR (Nikon D300s with AF-S Micro NIKKOR 105mm lens and NIKON R1C1 Twin Flash) and Mobile Phone (Apple I-Phone 11 with Selfie Ring Light). Assessment of 20 sets of intraoral photographs (100 individual images) by five IIUM orthodontists using a perceived quality Likert scale of Zero (0) to Ten (10). The assessors and the lead investigator were blinded to the source of the photographs. Reliability was evaluated using a test-retest method on 4 sets of intraoral photographs (20 individual images), a few weeks after their initial assessment. There was no significant difference (p=0.35) in perceived quality of intraoral photographs taken between DSLR and mobile phone, with the mean value of 7.34 and 7.12 respectively. Reliability was good (ICC=0.549). This prospective study showed that there was no statistical difference between the perceived quality of intraoral orthodontic photographs taken with a DSLR camera and a Mobile Phone camera.

Holographic Einstein ring of a charged Rastall AdS black hole with bulk electromagnetic field* *Supported by the National Natural Science Foundation of China (11675140, 11705005, 12375043), the Innovation and Development Joint Foundation of Chongqing Natural Science Foundation (CSTB2022NSCQ-LZX0021), and the Basic Research Project of Science and Technology Committee of Chongqing (CSTB2023NSCQ-MSX0324)

We study the Einstein images of a charged Rastall AdS black hole (BH) within the fabric of AdS/CFT correspondence. Considering the holographic setup, we analyze the amplitude of the total response function for various values of model parameters. With an increase in parameter λ and temperature T, the amplitude of the response function decreases, while it increases with an increase in electric charge e and chemical potential μ. The influence of frequency ω also plays an important role in the bulk field, as it is found that decreasing ω leads to an increase in the periods of the waves, which means that the amplitude of the response function also depends on the wave source. The relation between T and the inverse of the horizon for various values of parameter λ is interpreted under fixed values of other involved parameters. These, in turn, affect the behavior of the response function and the Einstein ring, which may be used to differentiate the present study from previous ones. We construct the holographic images of the BH in bulk via a special optical system. The results show that the Einstein ring always appears with concentric stripes at the position of the north pole, and this ring transforms into a luminosity-deformed ring or bright light spot when the distant observer lies away from the north pole. Finally, we discuss the influence of the associated parameters on the Einstein ring radius, which is consistent with wave optics.

Physics Design of a 200-MeV Electron Injector Linac With a Thermionic Electron Gun for the Korean Fourth-Generation Storage Ring Light Source

Physics Design of a 200-MeV Electron Injector Linac With a Thermionic Electron Gun for the Korean Fourth-Generation Storage Ring Light Source

(117) Interrater Agreement and Feasibility of Three-Dimensional Photography for Curvature Assessment in Peyronie's Disease

Abstract Introduction Curvature assessment is an iterative aspect of the evaluation of Peyronie’s Disease (PD); its accuracy is subject to patient erection quality and clinician technique. Prior studies have shown promising results when using 3D modeling software in curvature assessment, yet none have applied the technology to human subjects with complex PD in an authentic clinical scenario. Objective To evaluate the feasibility of using 3D modeling to assess penile deformity in PD patients. Methods MirrorMe3D is a HIPPA-compliant iOS mobile and web-based platform designed for 3D anatomical modeling. 2 trained urology fellows (coders 1 and 2) were trained to create models using the app by acquiring ≥ 12 images of the target obtained in a multiplanar, 360-degree fashion. Participants verbally consented to deidentified penile photography during their clinic visit for penile curvature assessment with Doppler ultrasound (CADUS). Photographs were obtained prior to performing DUS with the patient in the supine position and using a commercially available clip-on ring light and custom 3D-printed holder device placed over the penis base for stabilization. 3D models were generated upon completion of the visit and screened for quality. Curvature assessment on the 3D images included curvature direction, location, degrees, and other defects identified via visual inspection of the digital model. Results 7 unique, quality 3D images were generated using 15-20 photos per participant (Figure 1). The time required to obtain images was 1-2 minutes. Once the 3D image was developed, the curvature assessment took about 5 minutes. Quantitative results are summarized in Table 1. We observed a high rate of agreement in terms of primary direction of curvature and an acceptable variance rate when evaluating degrees of curvature within a margin of 10°; of note, coders were in agreement with each other to within a 10° margin 100% of the time (7/7 patients). We also observed a high agreement rate when evaluating the presence of absence of tapering but low agreement when assessing for the presence of indentation and hourglass deformity. Regarding the penis stabilizer, our experience suggests that it may alter the base of the penis anatomy, but it improves capture of the organ with diminished interference from surrounding anatomy (scrotum, abdomen). Factors influencing the quality of the image were exam room set-up, patient anxiety about losing an erection, lighting, and body hair. Conclusions 3D image-based PD assessment can be implemented with minimal impact to visit efficiency. The 3D technique does not appear to reproduce complex PD measurements obtained by CADUS; however, future studies will evaluate the utility of employing this technology to a larger cohort and also to monitor treatment effect in complex PD patients. Disclosure No.

A liquid-crystal microlens with dual-layers arrayed pattern electrode for the effective modulation of incident light beams

In this paper, an electrically controlled liquid crystal (LC) microlens array based on dual-layer arrayed planar pattern electrode is reported for effective light wave modulation. By adjusting the voltages applied to two planar arrayed electrodes within one substrate of the LC microlens, an adjustable focused circular ring or point-shaped light spot can be formed. Dual-layers arrayed pattern electrode with a minimum interval spacing of approximately ~10μm and a maximum of 130μm are achieved on one substrate by using standard microelectronic lithography, etching, coating film, and other processes. Experimental results are presented and discussed to illustrate outstanding performance of electrically focusing and modulation capability of the proposed LC device. This approach will serve as inspiration for the continued development and design of LC optical elements, enabling applications such as light field imaging, wavefront detection/correction, and the advancement of imaging augmented systems.

Bimodal design of 500MHz and 1.5GHz normal conducting RF cavity for advanced synchrotron radiation facilities

The advanced storage ring light source needs to realize ultra-low emissivity beam operation, and improving the Touschek lifetime puts forward higher requirements for the performance of RF cavity. In this paper, a novel bimodal normal conducting RF cavity is proposed. In one cavity, two power sources will be connected at the same time to realize the simultaneous operation of the two frequencies. The TM010 mode with the frequency of 500 MHz is used for acceleration, and the TM020 mode with the frequency of 1.5 GHz is used as the third harmonic to improve the height of the RF bucket and achieve the purpose of lengthening the beam bunch. Two couplers are designed to adapt to the working characteristics of bimodal RF cavity.

Hefei Advanced Light Facility: Empowering research of correlated electron systems

The Hefei Advanced Light Facility is the fourth-generation diffraction-limited storage ring light source, scheduled to begin operation in 2028. With its high-brightness and highly coherent X-rays, it will break through the current spatiotemporal resolution bottlenecks of X-ray techniques in studying correlated electron systems, providing crucial information for understanding the nature and microscopic origins of novel physical properties in these materials. This article introduces the main scientific goals and technical advantages of the Hefei Advanced Light Facility, focusing on the application perspectives of advanced technologies such as angle-resolved photoemission spectroscopy, magnetic circular dichroism, coherent X-ray scattering, and coherent X-ray imaging in researches of quantum materials and correlated electron systems. These techniques will enable the detailed analysis of the distribution and dynamics of electronic/spin/orbital states, reveal various novel quantum phenomena, and elucidate the fluctuations of order parameters in correlated electron systems. The completion of the Hefei Advanced Light Facility will provide advanced technical supports for decoding complex quantum states and non-equilibrium properties, ultimately promoting the application of quantum materials and correlated electron systems in frontier fields such as energy and information.

Ring Light Spot Adjustable Signal Combiner with High Power and Large Core Diameter

Ring Light Spot Adjustable Signal Combiner with High Power and Large Core Diameter

Association between linear enamel hypoplasia, cribra orbitalia and porotic hyperostosis in a South African skeletal sample

Background: Linear enamel hypoplasia (LEH) and porous cranial lesions such as cribra orbitalia (CO) and porotic hyperostosis (PH) are considered nonspecific indicators of early childhood metabolic stress. Objectives: The study aims to describe the association of LEH with CO and PH in a sample of the Kirsten Skeletal Collection (KSC) rep- resenting a cohort in the Western Cape, South Africa. This will be used to determine if one or more of these lesions can be used as an indicator of adult mortality. Sample and Methods: Skulls (n = 412) of both sexes with known demo- graphics from the KSC were macroscopically scored for LEH, CO and PH lesions using a ring light. This study was ethically approved by the Health Research and Ethics Committee of Stellenbosch Uni- versity (S13/05/100).Statistical chi-square tests were used to deter- mine the association between lesions and student’s t-tests to deter- mine if there was a significant difference in mean age-of-death be- tween groups. Results: There was no association when comparing LEH with CO and PH in the cohort, although an association was found between CO and PH. Individuals who exhibited the pathological lesions for LEH, CO or PH (or a combination thereof) were observed to have a younger mean age-at-death than the individuals without any of the three disease lesions. Conclusions: The lesions may potentially be used as an indicator of adult mortality. However, the results of this study might represent a biased population of low socio-economic status in the Western Cape as represented in the KSC, rather than the general population of the region.

Design strategies and technology of Elettra 2.0 for a versatile offer to the user community

Elettra 2.0 will be a fourth generation storage ring light source replacing the existing Elettra synchrotron. This article illustrates design strategies, physical investigations and technical choices to meet multiple and sometimes conflicting requirements. These include to make Elettra 2.0 a fully transversely coherent source up to 0.5 keV-photon energy, diversify the type of experiments through a very broad range of photon energies, from infrared to hard x-rays, maximize the number of photon beamlines in excess of 2-times the machine periodicity, and be able to produce picosecond-long light pulses at MHz repetition rate without interference to the standard multi-bunch operation. Most recent advancements in beam physics, technical systems and installation plan are reported with some detail.

AI-Accelerated Digitisation of Insect Collections: The next generation of Angled Label Image Capture Equipment (ALICE)

The digitisation of natural science specimens is a shared ambition of many of the largest collections, but the scale of these collections, estimated at at least 1.1 billion specimens (Johnson et al. 2023), continues to challenge even the most resource-rich organisations. The Natural History Museum, London (NHM) has been pioneering work to accelerate the digitisation of its 80 million specimens. Since the inception of the NHM Digital Collection Programme in 2014, more than 5.5 million specimen records have been made digitally accessible. This has enabled the museum to deliver a tenfold increase in digitisation, compared to when rates were first measured by the NHM in 2008. Even with this investment, it will take circa 150 years to digitise its remaining collections, leading the museum to pursue technology-led solutions alongside increased funding to deliver the next increase in digitisation rate. Insects comprise approximately half of all described species and, at the NHM, represent more than one-third (c. 30 million specimens) of the NHM’s overall collection. Their most common preservation method, attached to a pin alongside a series of labels with metadata, makes insect specimens challenging to digitise. Early Artificial Intelligence (AI)-led innovations (Price et al. 2018) resulted in the development of ALICE, the museum's Angled Label Image Capture Equipment, in which a pinned specimen is placed inside a multi-camera setup, which captures a series of partial views of a specimen and its labels. Centred around the pin, these images can be digitally combined and reconstructed, using the accompanying ALICE software, to provide a clean image of each label. To do this, a Convolutional Neural Network (CNN) model is incorporated, to locate all labels within the images. This is followed by various image processing tools to transform the labels into a two-dimensional viewpoint, align the associated label images together, and merge them into one label. This allows users to manually, or computationally (e.g., using Optical Character Recognition [OCR] tools) extract label data from the processed label images (Salili-James et al. 2022). With the ALICE setup, a user might average imaging 800 digitised specimens per day, and exceptionally, up to 1,300. This compares with an average of 250 specimens or fewer daily, using more traditional methods involving separating the labels and photographing them off of the pin. Despite this, our original version of ALICE was only suited to a small subset of the collection. In situations when the specimen is very large, there are too many labels, or these labels are too close together, ALICE fails (Dupont and Price 2019). Using a combination of updated AI processing tools, we hereby present ALICE version 2. This new version of ALICE provides faster rates, improved software accuracy, and a more streamlined pipeline. It includes the following updates: Hardware: after conducting various tests, we have optimised the camera setup. Further hardware updates include a Light-Emitting Diode (LED) ring light, as well as modifications to the camera mounting. Software: our latest software incorporates machine learning and other computer vision tools to segment labels from ALICE images and stitch them together more quickly and with a higher level of accuracy, significantly reducing the image processing failure rate. These processed label images can be combined with the latest OCR tools for automatic transcription and data segmentation. Buildkit: we aim to provide a toolkit that any individual or institution can incorporate into their digitisation pipeline. This includes hardware instructions, an extensive guide detailing the pipeline, and new software code accessible via Github. Hardware: after conducting various tests, we have optimised the camera setup. Further hardware updates include a Light-Emitting Diode (LED) ring light, as well as modifications to the camera mounting. Software: our latest software incorporates machine learning and other computer vision tools to segment labels from ALICE images and stitch them together more quickly and with a higher level of accuracy, significantly reducing the image processing failure rate. These processed label images can be combined with the latest OCR tools for automatic transcription and data segmentation. Buildkit: we aim to provide a toolkit that any individual or institution can incorporate into their digitisation pipeline. This includes hardware instructions, an extensive guide detailing the pipeline, and new software code accessible via Github. We provide test data and workflows to demonstrate the potential of ALICE version 2 as an effective, accessible, and cost-saving solution to digitising pinned insect specimens. We also describe potential modifications, enabling it to work with other types of specimens.

How video conferencing promotes preferences for self-enhancement products

The pandemic has led to a significant increase in the use of video conferencing platforms such as Zoom, Google Meet and Microsoft Teams. Yet little is known about the impact of video conferencing on subsequent consumer decisions. Across six studies, we examine the effects of video conferencing in both consumption (e.g., sales) and nonconsumption (e.g., school and work) contexts and find that video conferencing can trigger greater interest in products that can enhance the self - physically, intellectually, and/or mentally - due to heightened social appearance anxiety. This effect is attenuated when technology allows users to reduce social appearance anxiety (e.g., the use of ring lights or the ability to turn off web cameras) but accentuated when social anxiety is increased (e.g., the use gallery/speaker views) and is more pronounced among consumers who are low in self-esteem.

Applications of vertical damping wigglers in an X-ray diffraction limited storage ring

This study presents a lattice design for an X-ray diffraction limited storage ring (DLSR) light source with a circumference of 864 m and achieving an ultralow natural emittance of 25.6 pm·rad (N-IBS). However, the ultra-low emittance and long damping times lead to significant intra-beam scattering (IBS) effects. To address this issue, the study explores the implementation of vertical damping wigglers (VDWs) to decrease damping times, reduce beam horizontal emittance, and generate vertical emittance to achieve a “round beam” in the 864mDLSR. Through theoretical analysis and accelerator toolbox (AT) simulations, the impacts of VDWs with varied parameters were investigated, and the optimal period length, peak field, and total length were determined. Additionally, the twelve quadrupole magnets in both the front and rear cells of the VDWs were employed to correct linear optics. The findings demonstrate that VDWs could significantly reduce the beam's equilibrium emittance and damping times of the 864mDLSR. Furthermore, a comparison between the spectral brightness and flux of the 864mDLSR with and without VDWs revealed that the 864mDLSR employing VDWs yielded higher brightness and flux.

Method and Installation for Efficient Automatic Defect Inspection of Manufactured Paper Bowls

Various techniques were combined to optimize an optical inspection system designed to automatically inspect defects in manufactured paper bowls. A self-assembled system was utilized to capture images of defects on the bowls. The system employed an image sensor with a multi-pixel array that combined a complementary metal-oxide semiconductor and a photo detector. A combined ring light served as the light source, while an infrared (IR) LED matrix panel was used to provide constant IR light to highlight the outer edges of the objects being inspected. The techniques employed in this study to enhance defect inspections on produced paper bowls included Gaussian filtering, Sobel operators, binarization, and connected components. Captured images were processed using these technologies. Once the non-contact inspection system’s machine vision method was completed, defects on the produced paper bowls were inspected using the system developed in this study. Three inspection methods were used in this study: internal inspection, external inspection, and bottom inspection. All three methods were able to inspect surface features of produced paper bowls, including dirt, burrs, holes, and uneven thickness. The results of our study showed that the average time required for machine vision inspections of each paper bowl was significantly less than the time required for manual inspection. Therefore, the investigated machine vision system is an efficient method for inspecting defects in fabricated paper bowls.

Study of Regression Algorithms and Influent Factors between Intelligent Compaction Measurement Values and In-Situ Measurement Values

Intelligent compaction (IC) technology have been used for quality control and quality assurance (QC/QA) in subgrade construction. The effective regression correlations between Intelligent Compaction Measurement Values (ICMV) and In-situ Measurement Values (ISMV, including compaction degree and subgrade modulus ELWD) are the essential prerequisite of using IC technology for QC/QA. This paper presents the results from an experimental research study that was conducted from a practical subgrade project of China to explore the regression relationships between ICMV and ISMV. Three types of ICMV, including CMV, CCV and Evib, were collected along with the corresponding positions of the rollers. Two types of ISMV, containing compaction degree and ELWD, were measured by ring sampler method and light weight deflectometer (LWD) at specified test points, respectively. Based on these data, the influences of roller parameters and subgrade properties on the regression relationships of ICMV and ISMV were investigated. In addition, linear regression and 5 nonlinear regression algorithms were compared. The results suggest that ICMV reflect the stiffness of subgrade more than reflecting the density. In the regression of ICMV and ISMV, subgrade properties are more important than roller parameters while both of them should not be neglected. The influences of underlying stiffness and roller amplitude are linear while that of roller speed and moisture content are nonlinear. Nonlinear algorithms, especially the random forest, have the better performance compared to linear algorithm. Moreover, the combination of random forest and linear algorithm can further improve the accuracy of ISMV prediction.

“My Little Influencer”

“My Little Influencer”