Camera Tube Research Articles

Status of the large size telescopes and medium size telescopes for the Cherenkov Telescope Array observatory

Abstract The Cherenkov Telescope Array (CTA) is the next generation of ground-based observatory in the Very High Energy (VHE) gamma-ray domain. The observatory, operating in an open, all-sky mode, will consist of two sites, one in the Northern Hemisphere, at Observatorio Roque de los Muchachos (La Palma, Spain), and another in the Southern Hemisphere. CTA will implement Imaging Atmospheric Cherenkov Telescopes (IACTs) of large, medium and small size, mapping the VHE sky with an unprecedented sensitivity in an extended energy range. In its baseline design, 4 Large Size Telescopes (LSTs) will operate in coincidence in each site, dominating the CTA sensitivity in the 20 GeV – 150 GeV gamma-ray band, while the CTA core energy range, from 150 GeV to 5000 GeV, will be best covered by Medium Size Telescopes (MSTs), 25 in CTA-South and 15 in CTA-North. Each LST will be based on a 23 m diameter segmented, light-weight reflector , incorporating an active mirror control system, and a fast Photo-Multiplier Tube (PMT) camera. These features will allow CTA to observe extragalactic sources up to redshifts larger than two and to improve the sensitivity in observing gamma-ray transients. A prototype LST is currently under construction at the CTA-North site. A commissioning and validation phase will follow, which will mark the beginning for the construction of the rest of the LSTs of CTA-North and CTA-South. The MSTs, with an aperture of 10–12 m, are being explored in two different design options. One is based on the traditional IACT Davies–Cotton optical system and PMT-based cameras (FlashCam and NectarCAM), which is perfected after the experience from current HESS, MAGIC and VERITAS observatories. An alternative approach, based on the novel Schwarzschild–Couder optical system and Silicon-Photo-Multiplier-based camera, is also being developed to improve angular resolution. In this contribution, we will review the status of the prototypes of the LST and both MSTs for CTA.

Development of Ultrahigh-sensitivity HARP Pickup Tubes

Development of Ultrahigh-sensitivity HARP Pickup Tubes

2-2 X線用HARP撮像管

2-2 X線用HARP撮像管

2-1 撮像管用機能分離型電子銃の基礎検討

2-1 撮像管用機能分離型電子銃の基礎検討

Design of Defect Detection System for Valve

To meet the demand of high precision and high speed of modern industrial inspection, this paper realizes defect detecting in the inner hole of valve. This paper builds a detection system using CCD camera and hard tube endoscope. Through the operation of the test bench can complete to collect image information. Collecting image distortion due to the bending of the bore itself and distortion of the camera lens, so it is necessary to eliminate distortion, image cutting, filtering and other operations before image matching, then, stitching image with Scale Invariant Feature Transformation algorithm (SIFT). The weighted average method is used to deal with the overlapped area of the image in the image stitching, continuously, a completed hole image of valve sleeve is obtained. Finally, use algorithm of template match between template and detection image to complete defect detection.

Feasibility of an endotracheal tube-mounted camera for percutaneous dilatational tracheostomy.

Percutaneous dilatational tracheostomy (PDT) in critically ill patients is often led by optical guidance with a bronchoscope. This is not without its disadvantages. Therefore, we aimed to study the feasibility of a recently introduced endotracheal tube-mounted camera (VivaSight™-SL, ET View, Misgav, Israel) in the guidance of PDT. We studied 10 critically ill patients who received PDT with a VivaSight-SL tube that was inserted prior to tracheostomy for optical guidance. Visualization of the tracheal structures (i.e., identification and monitoring of the thyroid, cricoid, and tracheal cartilage and the posterior wall) and the quality of ventilation (before puncture and during the tracheostomy) were rated on four-point Likert scales. Respiratory variables were recorded, and blood gases were sampled before the interventions, before the puncture and before the insertion of the tracheal cannula. Visualization of the tracheal landmarks was rated as 'very good' or 'good' in all but one case. Monitoring during the puncture and dilatation was also rated as 'very good' or 'good' in all but one. In the cases that were rated 'difficult', the visualization and monitoring of the posterior wall of the trachea were the main concerns. No changes in the respiratory variables or blood gases occurred between the puncture and the insertion of the tracheal cannula. Percutaneous dilatational tracheostomy with optical guidance from a tube-mounted camera is feasible. Further studies comparing the camera tube with bronchoscopy as the standard approach should be performed.

Gamma-ray observations under bright moonlight with VERITAS

Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so IACTs cannot be operated in the same configuration in the presence of bright moonlight as under dark skies. Since September 2012, observations have been carried out with the VERITAS IACTs under bright moonlight (defined as about three times the night-sky-background (NSB) of a dark extragalactic field, typically occurring when Moon illumination > 35%) in two observing modes, firstly by reducing the voltage applied to the PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to the cameras. This has allowed observations at up to about 30 times previous NSB levels (around 80% Moon illumination), resulting in 30% more observing time between the two modes over the course of a year. These additional observations have already allowed for the detection of a flare from the 1ES 1727 + 502 and for an observing program targeting a measurement of the cosmic-ray positron fraction. We provide details of these new observing modes and their performance relative to the standard VERITAS observations.

電界放出陰極アレイを用いた超高感度平面撮像管の開発

A 640×480 pixel field emitter array (FEA) image sensor with a high-gain avalanche rushing amorphous photoconductor (HARP) target was fabricated and tested as a step toward the development of ultrahigh-sensitivity compact image sensors for high-definition TV cameras. Experiments showed that the prototype sensor could obtain clear images with little noise under illumination on a level equivalent to moonlight, with sufficient resolution while consuming far less power than current ultrahigh-sensitivity pickup tubes. Furthermore, various technologies which were suitable for practical image sensor have been developed.

Differences in motor variability among individuals performing a standardized short-cycle manual task

Motor variability (MV) has been suggested to be a determinant of the risk for developing musculoskeletal disorders in repetitive work. In this study we examined whether individuals consistently differed in the extent of motor variability when performing a standardized short-cycle manual task. On three separate days, arm kinematics was recorded in 14 healthy subjects performing a pipetting task, transferring liquid from a pick-up tube to eight target tubes with a cycle time of 2.8s. Cycle-to-cycle standard deviations (SD) of a large selection of shoulder and elbow kinematic variables, were processed using principal component analysis (PCA). Thereafter, between-subjects and between-days (within-subject) variance components were calculated using a random effects model for each of four extracted principal components. The results showed that MV differed consistently between subjects (95% confidence intervals of the between-subjects variances did not include zero) and that subjects differed consistently in MV between days. Thus, our results support the notion that MV may be a consistent personal trait, even though further research is needed to verify whether individuals rank consistently in MV even across tasks. If so, MV may be a candidate determinant of the risk of developing fatigue and musculoskeletal disorders in repetitive occupational work.

Shape Optimization of the Pick-Up Tube in a Pitot-Tube Jet Pump

At a very low specific speed (VLSS), pumps normally suffer from high disk friction losses. In order to solve this issue, it can be helpful to use a different centrifugal pump design, which is not often found in the pump industry: the Pitot-tube jet pump (PTJ pump). It shows superior performance at low specific speed due to a rather unconventional working principle, described in detail in this paper. The key design feature of the PTJ pump is the (fixed) pick-up tube. Its geometry has not varied over the last decades; it is referred to in this study as “initial” or “standard” design configuration. However, optimizing the pick-up tube might lead to a considerably higher performance. Therefore, a parameterized three-dimensional (3D) computer-aided design (CAD) model is used in this study to investigate the impact of shape deformation on pump performance with the help of computational fluid dynamics (CFD). Two CFD approaches are presented and compared for this purpose: a computationally efficient approach with limited accuracy (low-fidelity method) and a more detailed, but computationally more expensive, high-fidelity approach. Using both approaches, it is possible to obtain highly efficient PTJ pumps. As a consequence, first design rules can be derived. Finally, the optimized design has been tested for various operation points, showing that the performance is favorably impacted along the complete characteristic curve.

FLUORESCENT X-RAY IMAGING WITH PINHOLE CAMERA

Pinhole camera is one of X-ray optics devices. The pinhole camera is used for obtaining the image of synchrotron and laboratory sources, and also as a lens in a method of X-ray fluorescent microscopy. This method allows to obtain information on a spatial distribution of various chemical elements to the areas of several square centimeters with spatial resolution at the level of 50–100 μm. As a rule energy-dispersive two-dimensional CCD cameras are used for imaging. Such cameras are expensive devices and have low sensitivity for X-rays with energy of photons higher than 8 keV. Therefore it is perspective to use for X-ray fluorescent microscopy more effective CCD cameras with a scintillator layer. The purpose of this work consists in development of the device for imaging with secondary fluorescent X-rays by using pinhole as a lens and CCD camera for registration of the X-ray image. The device for obtaining the image of objects in secondary X-rays is developed. The device consists of an X-ray tube, pinhole and CCD camera. The object of research was irradiated with radiation from the X-ray tube and emits secondary X-rays. 100-microns pinhole was used for formation of the image of the object at an entrance window of the CCD camera. Images of a number of the iron springs differing in the sizes are received. It is established that the spatial resolution of the device is about 200 μm at an exposition of 60 s. It is possible to improve permission of the device by increasing in an exposition, optimization imaging conditions and reduction of the pinhole size.

Wireless electrochemiluminescence bipolar electrode array for visualized genotyping of single nucleotide polymorphism.

The development of simple, inexpensive, hand-held, user-friendly biosensor for high throughput and multiplexed genotyping of various single nucleotide polymorphisms (SNPs) in a single run experiment by a nonspecialist user is the main challenge in the analysis of DNA. Visualizing the signal and possibility to monitor SNPs by a digital camera opens a new horizon for the routine applications. In the present manuscript, a novel wireless electrochemiluminescence (ECL) DNA array is introduced for the visualized genotyping of different SNPs on the basis of ECL of luminol/hydrogen peroxide system on a bipolar electrode (BPE) array platform. After modification of anodic poles of the array with the DNA probe and its hybridization with the targets, genotyping of various SNPs is carried out by exposing the array to different monobase modified luminol-platinum nanoparticles (M-L-PtNPs). Upon the hybridization of M-L-PtNPs to mismatch sites, the ECL of luminol is followed using a photomultiplier tube (PMT) or digital camera and the images are analyzed by ImageJ software. This biosensor can detect even thermodynamically stable SNP (G-T mismatches) in the range of 2-600 pM. Also, by combining the advantages of BPE and the high visual sensitivity of ECL, it could be easily expected to achieve sensitive screening of different SNPs. The present biosensor demonstrates the capability for the discrimination between PCR products of normal, heterozygous, and homozygous beta thalassemia genetic disorders.

Experiments on the range resolution measurement of a slit Streak Tube Imaging Lidar

This paper describes the range resolution of a linear focal plane arrays imaging lidar. Through the measurement experiments of a flash lidar imaging technique that uses a streak tube (K008) camera as a receiver, range resolution under different conditions has been discussed. Its range accuracy can be about 2cm under laboratory conditions, less than 0.65m during long distance (4km) target detection, and 1.5cm in the experiment of underwater targets measurement, which are in accordance with the theoretical calculating values.

Fluid Flow in the Oil Pumping System of a Hermetic Compressor

This work deals with the investigation of the oil pumping system in hermetic compressors for refrigeration application. The oil pump which is used for this study consists of two pumping areas: the lower pumping area with a pick-up tube and an eccentric bore, and the upper pumping area with a helical groove. This study focuses on the helical groove in the upper pumping area. To analyse the fluid flow in the helical groove, a numerical approach is introduced. In this approach the Navier-Stokes equations are adapted to the problem and are solved by using the finite volume method. Compared to analytical models, this method is able to obtain the flow field in the cross section of the helical groove at higher resolution. The higher geometrical resolution also enables the analysis of the flow in the small gap between the rotating crankshaft and the stationary wall. The present method is used to quantify different operating parameters on the oil mass flow rate.

Effects of concurrent physical and cognitive demands on arm movement kinematics in a repetitive upper-extremity precision task

The effect of concurrent physical and cognitive demands on arm motor control is poorly understood. This exploratory study compared movement kinematics in a repetitive high-precision pipetting task with and without additional concurrent cognitive demands in the form of instructions necessary to locate the correct target tube. Thirty-five healthy female subjects performed a standardized pipetting task, transferring liquid repeatedly from one pick-up tube to different target tubes. In the reference condition, lights indicated the target tube in each movement cycle, while the target tube had to be deciphered from a row and column number on a computer screen in the condition with additional cognitive demands. Kinematics of the dominant arm was assessed using the central tendency and variability of the pipette-tip end-point trajectory and joint kinematics properties of the shoulder and elbow. Movements slowed down (lower velocities and higher area under the movement curves) and trajectory variability increased in the condition with additional cognitive demands, but there were no changes in the kinematics properties such as joint range of motion, times of acceleration and deceleration (as indicated by the time to peak velocity), average angles, or phase relationships between angle and angular velocity of shoulder or elbow movements between the two conditions. Further, there were also no differences in the size or structure of variability of the shoulder and elbow joint angles, suggesting that subjects could maintain the motor repertoire unaltered in the presence of these specific additional cognitive demands. Further studies should address motor control at other levels of concurrent cognitive demands, and with motor tasks that are less automated than the pipetting task used in the present study, so as to gain an increased understanding of the effect of concurrent cognitive demands for other activities of relevance to daily life.

Photoelectric conversion characteristics of c-Se-based thin-film photodiodes in imaging device

Herein, we report the use of high-efficiency crystalline-selenium-based (c-Se-based) thin-film heterojunction photodiodes in imaging devices. As a novel experiment, we use an image pickup tube with a photoelectric conversion layer consisting of n-gallium oxide (Ga2O3)/p-c-Se heterojunction photodiodes to obtain high-resolution images at a relatively low applied voltage. We reduce the thickness of the Ga2O3 layer to expand the depletion layer into the c-Se layer at a lower applied voltage. In addition, Sn-doping of the Ga2O3 layer effectively increases the carrier concentration, thereby allowing the photodiode to operate at lower voltage.

Nonlinear metrics assessing motor variability in a standardized pipetting task: Between- and within-subject variance components

The aim of this study was to estimate the between days test–retest reliability of nonlinear metrics used to quantify motor variability in a repetitive pipetting task. On three separate days, 14 healthy subjects performed pipetting as a general model of repetitive tasks. The task consisted of transferring liquid 20 times with a cycle time of 2.8s from a pickup tube to eight target tubes placed on a table in front of the subjects. The motion of hand, arm and the pipette tip was tracked in 3D and the shoulder elevation and elbow flexion angle were obtained. Motor variability was assessed using nonlinear metrics based on information theory and recurrence quantification analysis. Between- and within- (between-days) subject variance components were computed using a one-way random effect model, and intra-class correlation coefficients (ICC) were calculated from the variance components as standardized measures of reliability. Most of the metrics displayed a considerable between-days variance component and therefore the ICC showed a slight to moderate reliability. The reported data on between- and within-subject variability can be used to design future studies using nonlinear motor variability metrics on kinematics data.

A rapid response 64-channel photomultiplier tube camera for high-speed flow velocimetry

In this technical design note, the development of a rapid response photomultiplier tube camera, leveraging field-programmable gate arrays (FPGA) for high-speed flow velocimetry at up to 10 MHz is described. Technically relevant flows, for example, supersonic inlets and exhaust jets, have time scales on the order of microseconds, and their experimental study requires resolution of these timescales for fundamental insight. The inherent rapid response time attributes of a 64-channel photomultiplier array were coupled with two-stage amplifiers on each anode, and were acquired using a FPGA-based system. Application of FPGA allows high data acquisition rates with many channels as well as on-the-fly preprocessing techniques. Results are presented for optical velocimetry in supersonic free jet flows, demonstrating the value of the technique in the chosen application example for determining supersonic shear layer velocity correlation maps.

Improvement and Upgrade of Small-Angle X-ray Scattering Beamlines at the Photon Factory

Three small-angle X-ray scattering (SAXS) beamlines, BL-6A, BL-10C and new BL-15A2 are available at the Japanese synchrotron facility, Photon Factory (PF). We are recently improving and upgrading the SAXS beamlines at the PF in order to support new measurements and construct a high-throughput experimental system. BL-6A is a bending magnet beamline and the wavelength is fixed at 1.5 angstrom. This beamline had two detectors, PILAUS 300K (Dectris) for SAXS/GI-SAXS and PILATUS 100K (Dectris) for WAXD experiment, respectively, and the simultaneous measurement using these detectors are available. We installed a new experimental stage and replaced PILATUS 300K with PILATUS3 1M in this March. Therefore, the range of an applicable camera length spread to 0.25 ~ 2.5 m, and the detectable angle area expanded in the small-angle region. BL-10A is also a bending magnet beamline and the wavelength has been fixed at 1.488 angstrom. We replaced almost all the optical and experimental components of this beamline with new ones in this March. A fixed-exit double-crystal monochromator, a focusing mirror and a mirror bender were newly installed in this beamline. We will be able to change the energy from 6 to 14 keV. Although the photon flux at the sample position will not change after this upgrade, the area of the beam at the focal point will decrease to 40 % on the basis of the raytracing calculation. The camera length spread from 2 m to 3m in a new experimental stage with the camera tube. PILATUS3 2M and 200K (Dectris) were also installed as a detector. The commissioning will be started from this May, and the beamline will be re-opened from this June. In order to control all new devices and make the user-operation easier, we newly developed GUI software for the beamline control and the experiment. We are also developing the solution sample mixer and changer at BL-15A2 for the high-throughput Bio-SAXS measurement. We will present the current status of these beamline refurbishment.

Experiments of ocean surface waves and underwater target detection imaging using a slit Streak Tube Imaging Lidar

This letter describes a flash Lidar imaging technique that uses a streak tube camera as a receiver to detect short scale surface wave fields for oceanographic, underwater target and coastal measurements. The range and intensity imaging of short scale sea-waves and underwater targets can be supplied by this system through light reflected from the surface of the sea and targets. Through a surface scattering model, more accurate range and intensity information can be extracted. The technique can be applied to surface wave measurements and underwater target detection with high resolution. The feasibility of this technique is demonstrated by applying the technique to data acquired by shipborne Streak Tube Imaging Lidar (STIL) in the Yellow Sea and also the East and South China Seas.