Wide Viewing Research Articles

Neutronics analysis of the visible infrared wide angle viewing system in equatorial port #12 of ITER

The ITER Equatorial Visible and InfraRed Wide Angle Viewing System (VisIR WAVS) is a major system for the monitoring of the components facing the plasma. It is of utmost importance as it is involved in the machine protection, in basic and advanced controls, and in physics analyses. The diagnostic reaches the final phase of its design for the Equatorial Port #12 (EP#12) and IRFM designed a very detailed model for the In-Vessel part with three lines of sight implemented in EP#12. This paper presents the neutronics analyses that have been performed in the framework of two contracts with Fusion for Energy F4E, the FPA-407/SG#04 and GRT-1146 grants. The nuclear analyses covered mode-0 for the nuclear heating calculations in supply to the thermomechanical analyses.

Tests on the prototype of the Optical Hinge for the Wide Angle Viewing System to ITER gamma radiation conditions

The Wide Angle Viewing System (WAVS) for ITER is a major diagnostic for machine protection, plasma control and physics analysis. The diagnostic will measure the surface temperature of the plasma facing components by infrared thermography being one of its main roles to protect them from damage. It will also image the plasma emission in the visible range. The full system is composed of 15 lines of sights located in four equatorial ports (3, 9, 12 and 17).As part of the ex-vessel optics, the first element of the optical chain is the Optical Hinge (OH). It is constituted by two folding mirrors which face the port plug exit optical beam. The mission of this component is to compensate the differential motion between the vacuum vessel and the building, during normal operation and baking. This function will be performed by means of a piezo actuator coupled to the OH upper mirror (and a set of reference switches) to drive the vertical displacement of the mirror in order to get the desired alignment position of the optical beam. The piezo actuator has been identified as the main critical item of the OH what has motivated the fabrication of an OH prototype (for one line of sight) aimed at performing a set of tests to validate the piezo actuator under operation conditions. The tests have consisted in the characterization of the piezo actuator behavior with the nominal load after being irradiated to 272.40 kGy of total accumulated gamma dose, which is the dose expected in ITER. Moreover, additional tests have been conducted to find out the influence of the cable length from the piezo actuator to the controller in the performance. A description of these tests and the results obtained will be presented in the paper.

Electromagnetic analysis of the Interspace Afocal Module of the Wide Angle Viewing System diagnostic for ITER

The ITER Visible and Infrared Wide Angle Viewing System (WAVS) is a diagnostic aiming to optically monitor the tokamak first wall and divertor for machine protection, plasma control and physics analysis. The Interspace Afocal Module (IAM) is a refractive optical system, being one of the WAVS components located in the Interspace area.In order to assure the optical performance, the IAM has to withstand all the relevant loads defined for the Final Design, including the electromagnetic (EM) loads developed in the Interspace area under EM events. Volumetric forces during transient EM events arise from the interaction of the background magnetic field with the eddy currents induced in the conductive components when they experience time-varying magnetic fields. In case of Category III and IV loads, including load combinations with certain Major Disruption and Vertical Displacement Event cases, the IAM integrity has to be ensured since its structure is classified as Safety Relevant.The EM volumetric loads are calculated through a 3D Finite element model and will serve as inputs for the later structural analysis. The paper summarizes the EM analysis of the IAM, performed by CIEMAT, to validate its Final Design.

Bio‐Inspired Multi‐Responsive Structural Color Hydrogel with Constant Volume and Wide Viewing Angles

AbstractStructural color hydrogels (SCHs) have ushered in a new era for a variety of fields including sensing, display, and anti‐counterfeiting. Attempts in this area are trending to improve their functions to implement the practical values. Herein, bioinspired by chameleons, a novel multi‐responsive angle‐independent SCH is presented. The SCH consists of responsive poly(N‐isopropylacrylamide) (PNIPAM) with vivid structural colors replicated from photonic crystal particle templates, which is fixed within a non‐responsive hydrogel film. Due to the thermal‐sensitivity of PNIPAM, the distance between nanopores of inverse opal can be tuned, leading to a shift of the reflection peak. Besides, the structural colors are angle‐independent since the structural color elements are spherical. Intriguingly, as the elastic deformation of the non‐responsive hydrogel is only in local positions, the total volume of the SCH film is kept near‐constant, making its stability superior to traditional structural color films. To further broaden its function, reduced graphene oxide nanoparticles and carbon nanotubes are integrated into the SCH film to gain near‐infrared (NIR) photo‐thermal and electro‐thermal response. It is verified that the SCH can respond to temperature change, NIR irradiation, and electric signal, exhibiting chromatic shifting with constant volume and wide viewing angles, indicating unpredicted potential in diverse fields.

Design overview of ex-vessel components for the Wide Angle Viewing System diagnostic for ITER Equatorial Port 12

The ITER equatorial visible and infrared Wide Angle Viewing System (WAVS) provides surface temperature measurements of plasma facing components by infrared (IR) thermography being one of its main roles to protect them from damage. It also images the plasma emission in the visible range. The diagnostic, which comprises 15 lines of sight distributed in four equatorial ports (3, 9, 12 and 17), will contribute to Machine protection, Basic control and Physics analysis in ITER. The design of the diagnostic in the equatorial port 12 (EP12) - comprising three lines of sight - is currently being developed within a Framework Partnership Agreement through a Specific Grant granted by F4E to the Consortium formed by CEA, Ciemat and Bertin Technologies. EP12 has to be operative for the ITER first plasma. The overview of the WAVS opto-mechanical design for the ex-vessel components in EP12 will be presented in the paper. The ex-vessel optics are composed of mirrors and refractive elements which relay the exit image of the port plug at the vacuum window up to the cameras placed inside a shielded cabinet in the Port Cell. The image relay through the Interspace, Bioshield and Port Cell has to cover a length of almost 10 m in order to reach the detectors. The refractive elements are arranged in sub-assemblies (optical modules) mechanically mounted in barrels and next assembled on a support structure. The assembly of these modules on site will be also presented in the paper. Furthermore, the Optical Hinge which is the first component of the ex-vessel optical chain (formed by two folding mirrors) aims to compensate the differential motion between the vacuum vessel and the building, in normal operation and baking. The mechanical assembly and the operation of this component will be also described in the paper.

Optical design of ex-vessel components for the Wide Angle Viewing System diagnostic for ITER

The equatorial visible and infrared Wide Angle Viewing System (WAVS) for ITER is one of the key diagnostics for machine protection, plasma control and physics analysis. To achieve these objectives, the WAVS will monitor the surface temperature of the Plasma Facing Components by infrared (IR) thermography (3–5 μm range) and will image the edge plasma emission in the visible range. It will be composed of 15 lines of sight installed in four equatorial ports (no. 3, 9, 12 and 17) and will survey more than 80% of the overall area of the vacuum vessel. This paper presents the optical design of the ex-vessel optics, which is at Preliminary Design Status by the time this paper is published. The main function of the ex-vessel optics is to relay the scene image, and also the pupil image, coming from the Port-Plug Optics into a dedicated set of detectors, while keeping the required performance. The optics will work in two bands simultaneously, visible and Mid IR, and will use common refractive optics all along the optical path until it splits into the dedicated sensors at the Port Cell Cabinet. The optical system consists of several modules that comply with the different system interfaces and environmental constraints. A full description of the different modules, its function and performance, and the end to end optics performance will be described in this paper. The optics alignment strategy will be also described and the corresponding assembly and manufacturing tolerances.

37‐3: Novel Multi‐Domain Polymer Sustained Alignment LCD to Obtain High Transmittance and Wide Viewing Angles

Novel 2‐domain PSA pixel design was proposed to get better viewing angle experience. Furthermore, the viewing angle is IPS‐like level, and the transmittance gain is about 10.5% compared with the conventional 4‐domain PSA pixel.

Wide Viewing Zone and High-Resolution Autostereoscopic Display with Smooth Motion Parallax Using Crosstalk between Two Viewpoint Images in One Eye

Proceedings of the International Display Workshops Volume 27 (IDW '20),Wide Viewing Zone and High-Resolution Autostereoscopic Display with Smooth Motion Parallax Using Crosstalk between Two Viewpoint Images in One Eye

Fountain (PE-FFS) Technology for Wide Viewing Angle LCD

Fountain (PE-FFS) Technology for Wide Viewing Angle LCD

Dual-View Integral Imaging System With Wide Viewing Angle And High Spatial Resolution

In this paper, a dual-view integral imaging system is proposed to present two different 3D images for viewers in different viewing zones. For most of the conventional dual-view integral imaging systems, either the viewing angle or the spatial resolution of 3D image is decreased. In the proposed dual-view system, the viewing angle of each viewing zone is enlarged by introducing a switchable mask. Meanwhile, the spatial resolution of the 3D image is maintained by using the time-division multiplexing technology. A prototype of the proposed dual-view system is developed and it has wide viewing angle and high spatial resolution. The experiments coincide with the theoretical analysis.

57.5: Optimized Compensation Film for Automotive Display with Wide Viewing Angle

Wide viewing angle is a critical optical specification for liquid crystal displays (LCDs), particularly in automotive displays. We proposed an optimized compensation film which consists of a biaxial positive B film and a negative B film to improve the viewing angle of LCDs with Super Fine TFT (SFT) mode. Under optimized retardations, minimum contrast ratio in area A can tremendously reach 0.59 times of perpendicular contrast ratio which provides excellent viewing characteristics based on German OEM specification.

Dependence of the viewing angle control property of a guest-host liquid crystal cell on the extinction coefficient of the mixture.

The theoretical prediction of a display viewing angle control using a guest-host (GH) liquid crystal (LC) cell has been reported by Chen etal. [Jpn. J. Appl. Phys.48, 062401 (2009)JJAPA50021-492210.1143/JJAP.48.062401]. We experimentally confirmed the viewing angle control property of the GH cell and also investigated its dependence on the extinction coefficient of the GH mixture. The GH cell with a negative dielectric anisotropy and a vertical orientation was attached on front of the display panel, resulting in narrow viewing (NV) property at the field-off state. The GH molecules were switched to a planar orientation, which is also orthogonal to the polarization direction of light at the field-on state, showing wide viewing (WV) property. We varied the concentration of a guest dichroic dye in a host LC and measured the extinction coefficients of the mixtures. We simulated the viewing control property using the measured extinction coefficients and found that the horizontal viewing angle can be controlled using the GH cell, but the vertical viewing angle cannot be controlled. Then, we experimentally confirmed the horizontal viewing angle control using the GH cell. The extinction between the NV and the WV states was increased with a greater extinction coefficient of the GH molecules, but the transmittance was decreased.

Overview of optical designs of the port-plug components for the ITER Equatorial Wide Angle Viewing System (WAVS)

The equatorial visible and infrared Wide Angle Viewing System (WAVS) for ITER is one of the key diagnostics for machine protection, plasma control and physics analysis. To achieve these objectives, the WAVS will monitor the surface temperature of the Plasma Facing Components (PFCs) by infrared (IR) thermography (3–5 μm range) and will image the edge plasma emission in the visible range. It will be composed of 15 lines of sight installed in four equatorial ports (no. 3, 9, 12 and 17) in order to survey at least 80% of the overall area of the vacuum vessel. This paper presents the optical design of port-plug which has to cope with both challenging performances (wide field of view, wide temperature range 200–2000 °C, high measurement accuracy required lower than 20%) and severe constraints such as harsh nuclear environment, complex interfaces. Indeed the optical components are embedded within the ITER Diagnostic Shielding Module, DSM, which is not usual for diffraction limited instruments. It is shown that nominal optical performance of the Port-Plug are limited by the diffraction only. In operation, this design has demonstrated its superiority on the former ones since it is much less sensitive to tolerance variations.

Graphene Glass Inducing Multidomain Orientations in Cholesteric Liquid Crystal Devices toward Wide Viewing Angles.

The photonic reflection of a cholesteric liquid crystal (ChLC) device depends on the spatial distribution of the orientations of their helical axes, and many orientation techniques have been developed so far. In this study, we select the hybrids of graphene directly grown on quartz glass as platforms to construct ChLC-based devices. This special design makes graphene serve as both an alignment layer and a conductive layer, thus affording a more simplified device fabrication route. We reveal that multidomain structures can be evolved for ChLCs on polycrystalline monolayer graphene on quartz glass, as evidenced by polarized optical microscope characterizations. The disparate orientations of the helical axes of ChLCs and the formation of multidomain structures are proposed to be induced by the different domain orientations of graphene, leading to a wide viewing angle of the ChLC-based devices. Moreover, the pitch of ChLCs is also observed to play a key role in the relative orientations of ChLCs. A wide viewing angle of the ChLC-based device is also detected especially in the infrared spectrum region. Briefly, this work should provoke the application of graphene glass as a perfect transparent electrode in the fabrication of liquid-crystal-based devices showing broad application potentials in intelligent laser protection and energy-saving smart windows.

P‐159: Wide Viewing Angle Negative Dispersion Retarder by Stacking Reactive Mesogen with a Positive Birefringence on Stretched Film with a Negative Birefringence

We reported a wide viewing angle negative dispersion retarder film. We stacked the reactive mesogen (RM) and stretched polymethylmethacrylate (PMMA). The retardation (Re) was Re(450 nm)/ Re(550 nm) = 0.818, Re(650 nm)/ Re (550 nm) = 1.110. The out‐of‐plane retardation (Rth) was 6 nm. This value is much smaller than a general retarder and exhibits wide viewing angle property.

Paper] Design of VA-LCD System with Microstructure Film for Wide Viewing

We have developed a wide viewing VA-LCD system with the microstructure film. This film is attached on LC panel and scatters incident lights from LC panel by reflection at internal air cavities to improve the viewing angle characteristics. In this system, we have optimized LC alignment directions and BL distribution as well as the scattering profile of the film. LC panel has two-domain LC aligned pixel (each LC director is antiparallel in vertical direction) and wide viewing angle in horizontal direction. Backlight distribution is collimated to horizontal direction. To distribute lights in horizontal direction to vertical direction, we designed and fabricated the microstructure film which had rhombus shaped air cavities. This display system indicated smaller color shift and higher CR at oblique angles than the conventional VA-LCD; the color shift from the normal direction (Δu'v') at θ= 60° was reduced by 60% and the CR was over 100:1 at all directions.

Production of Structural Colors with High Contrast and Wide Viewing Angles from Assemblies of Polypyrrole Black Coated Polystyrene Nanoparticles.

Structural color with wide viewing angles has enormous potential applications in pigment, ink formulation, displays, and sensors. However, colors obtained from colloidal assemblies with low refractive index contrast or without black additives typically appear pale. Here, we prepare polypyrrole (PPy) black coated polystyrene (PS) nanoparticles and demonstrate well-defined colors with high color contrast and wide viewing angles under ambient light. Depending on the loading of pyrrole during polymerization, PPy nanogranules of different sizes and coverages are grafted to the surface of PS nanoparticles. The bumpy particles can self-assemble into quasi-amorphous arrays, resulting in low angle dependent structure colors under ambient light. The color can be tuned by the size of the PS nanoparticles, and the presence of the PPy black on PS nanoparticles enhances the color contrast by suppressing incoherent and multiple scattering.

4-3: Wide Viewing Angle TN LCD Enhanced by Printed Quantum-Dots Film

The low heavy metal and heavy metal free QDs (Cd < 100 ppm, Pb-free) content of the R, G, B-QDs was deposited on top of the conventional twist nematic (TN) liquid crystal device to improve the viewing angle of liquid crystal display. The non-vacuum, low materials consumption solution process by aerosol-jet deposition has the advantage of direct printing on black matrix pattern glass. The intensity of 410 nm was applied to execite the QD film and was modulated by the TN cell. As a result, the LC retardation and response time can be fully optimized within the small cell gap. In particular, the eco-QD array TNLCD possesses wide viewing angle, high transmittance, and fast response time (< 3 ms) under low driving voltage (4 V).

9-2: Optical Compensation Method for Wide Viewing Angle IPS LCD Using a Plastic Substrate

The problem of a sheet LCD using plastic substrates is the narrow viewing angle of the large retardation of typical plastic materials. We have developed the optical compensation and a new process for plastic IPS-LCD with wide viewing angle.

Full Resolution, Low Crosstalk, and Wide Viewing Angle Auto-Stereoscopic Display With a Hybrid Spatial-Temporal Control Using Free-Form Surface Backlight Unit

A full resolution, low crosstalk and wide viewing angle auto-stereoscopic display is demonstrated with the use of a novel free-form surface backlight (FFSB) technique, in conjunction with a hybrid spatial and temporal control scenario. The overall crosstalk coming from adjacent channels is shown to be lower than 5% even at a wide viewing angle, and minimum achievable crosstalk can be as small as 2.41%. The key element design giving rise to achieving the full viewing angle greater than 45 degrees is also presented.