scholarly journals Implementation and Use of Wide Fields in Future Very Large Telescopes

1984 ◽  
Vol 78 ◽  
pp. 549-562 ◽  
Author(s):  
J.R.P. Angel
Keyword(s):  
High Efficiency ◽  
Optical Design ◽  
Atmospheric Dispersion ◽  
General Purpose ◽  
Full Potential ◽  
Large Area ◽  
Full Field ◽  
Drift Scan ◽  
Large Telescopes ◽  
Ccd Arrays

AbstractThe full potential of the next generation of larger telescopes will be realized only if they have well instrumented large fields of view. Scientific problems for which very large ground-based optical telescopes will be of most value often will need surveys to very deep limits with imaging and slitless spectroscopy, followed by spectroscopy of faint objects taken many at once over the field. Improved instruments and detectors for this purpose are being developed. Remotely positioned fibers allow the coupling of light from many objects in the field to the spectrograph slit. CCD arrays, operated in the TDI or drift scan mode, will make large area detectors of high efficiency that may supercede photographic plates. An ideal telescope optical design should be based on a fast parabolic primary, have a field of at least 1° with achromatic images < 0.25 arcseconds and have provision for dispersive elements to be used for slitless spectroscopy and compensation of atmospheric dispersion over the full field. A good solution for a general purpose telescope that can satisfy these needs is given by a three element refractive corrector at a fast Cassegrain focus. A specialized telescope dedicated to sky surveys, with better image quality and higher throughput than presently available, might be built as a scaled up Schmidt with very large photographic plates. Better performance in most areas should be obtained with a large CCD mosaic detector operated in the drift scan mode at a telescope with a 2-mirror reflecting corrector.

Charles Gorrie Wynne. 18 May 1911 – 1 October 1999

2001 ◽  
Vol 47 ◽  
pp. 497-514
Author(s):  
Jonathan Maxwell ◽  
Prudence M.J.H. Wormell
Keyword(s):  
Bubble Chamber ◽  
Optical Design ◽  
Atmospheric Dispersion ◽  
Working Life ◽  
High Energy ◽  
Formative Period ◽  
Computer Assisted ◽  
Original Research ◽  
Lens Design ◽  
Large Telescopes

Charles Gorrie Wynne dedicated his professional life to optical design and became a principal figure in the international optical design community. When he died, he was optical consultant to the Institute of Astronomy in Cambridge and Emeritus Professor of Optical Design at Imperial College. Although nearly 90 years old he worked several days a week in the Institute of Astronomy until a few months before he died. He was elected to Fellowship of The Royal Society in 1970. Wynne's expertise was in the field of optical instrument design, particularly lens design. Among lens designers he is best known for his effective theories of lens design, his elegant and ambitious lens designs, and particularly his invention of a very successful method of computer-assisted lens design, based on the method of least squares. Among astronomers he is known for what is almost a monopoly of designs for field–widening optics for large telescopes, and also for a series of scientifically elegant spectrographs and atmospheric dispersion correctors. With microcircuit manufacturers he is famous for his work on the Wynne–Dyson catadioptric relay printer for microcircuit production. By high–energy physicists he is known as the designer of bubble–chamber optics; finally, he is known by his assistants and his students as their professional mentor. During the formative period of Charles Wynne's working life, optical design was performed almost exclusively behind the closed doors of optical factories. The optical designers in those factories traditionally led a monastic working life, closeted with a few close colleagues and assistants, grappling with the extensive numerical calculations that optical design involves. During the period of his career when he worked in this way, he managed to combine this type of working life with creative original research into new types of lens system and new methods of lens design.

HIGH EFFICIENCY, LARGE-AREA PHOTOVOLTAIC DEVICES USING AMORPHOUS Si : F : H ALLOY

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-463-C4-466
Author(s):  
A. Madan ◽  
W. Czubatyj ◽  
J. Yang ◽  
J. McGill ◽  
S. R. Ovshinsky
Keyword(s):  
High Efficiency ◽  
Photovoltaic Devices ◽  
Large Area ◽  
Amorphous Si

scholarly journals Design and Experimental Study of the General Mechanical Pneumatic Combined Seed Metering Device

2021 ◽  
Vol 11 (16) ◽  
pp. 7223
Author(s):  
Dengyu Xiong ◽  
Mingliang Wu ◽  
Wei Xie ◽  
Rong Liu ◽  
Haifeng Luo
Keyword(s):  
High Efficiency ◽  
Cone Angle ◽  
General Purpose ◽  
Optimal Performance ◽  
Air Velocity ◽  
General Properties ◽  
Response Surface Optimization ◽  
Damage Rate ◽  
Air Blowing ◽  
Seed Metering Device

To address the problems of high damage rate, low seeding accuracy, and poor seeding generally in the seeding process, a general-purpose seeding device was designed in this study based on the principle of mechanical pneumatic combined seeding. The air-blowing-type cleaning and seed unloading of the device laid the conditions for precise seeding and flexible seeding. In addition, single-factor experiments were performed on seeds (e.g., soybeans, corn, and rape-seeds) with different particle sizes and shapes to verify the general properties of the seed metering device. A multi-factor response surface optimization experiment was performed by applying soybean seeds as the test object to achieve the optimal performance parameters of the seed metering device. At a seed-clearing air velocity of 16.7 m/s, a seed feeding drum speed of 13.7 r/min, and a hole cone angle of 35.6°, corresponding to the optimal performance index, the qualified index, the replay index, and the missed index reached 97.94%, 0.03%, and 2.03%, respectively. The verification test results are consistent with the optimized ones. As indicated from the results, the seed metering device exhibits good general properties, low damage rate, great precision, and high efficiency; it is capable of meeting general seeding operations of different crop seeds and technically supporting for the reliability and versatility of the seeder.

scholarly journals Magneto-optical design of anomalous Nernst thermopile

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian Wang ◽  
Asuka Miura ◽  
Rajkumar Modak ◽  
Yukiko K. Takahashi ◽  
Ken-ichi Uchida
Keyword(s):  
Optical Design ◽  
Polarized Light ◽  
Ferromagnetic Material ◽  
Light Polarization ◽  
Optical Recording ◽  
Induced Voltage ◽  
Large Area ◽  
Circularly Polarized Light ◽  
Out Of Plane ◽  
Order Of Magnitude

AbstractThe introduction of spin caloritronics into thermoelectric conversion has paved a new path for versatile energy harvesting and heat sensing technologies. In particular, thermoelectric generation based on the anomalous Nernst effect (ANE) is an appealing approach as it shows considerable potential to realize efficient, large-area, and flexible use of heat energy. To make ANE applications viable, not only the improvement of thermoelectric performance but also the simplification of device structures is essential. Here, we demonstrate the construction of an anomalous Nernst thermopile with a substantially enhanced thermoelectric output and simple structure comprising a single ferromagnetic material. These improvements are achieved by combining the ANE with the magneto-optical recording technique called all-optical helicity-dependent switching of magnetization. Our thermopile consists only of Co/Pt multilayer wires arranged in a zigzag configuration, which simplifies microfabrication processes. When the out-of-plane magnetization of the neighboring wires is reversed alternately by local illumination with circularly polarized light, the ANE-induced voltage in the thermopile shows an order of magnitude enhancement, confirming the concept of a magneto-optically designed anomalous Nernst thermopile. The sign of the enhanced ANE-induced voltage can be controlled reversibly by changing the light polarization. The engineering concept demonstrated here promotes effective utilization of the characteristics of the ANE and will contribute to realizing its thermoelectric applications.

scholarly journals Efficient and large-area all vacuum-deposited perovskite light-emitting diodes via spatial confinement

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peipei Du ◽  
Jinghui Li ◽  
Liang Wang ◽  
Liang Sun ◽  
Xi Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Scale Production ◽  
Nonradiative Recombination ◽  
Large Area ◽  
Spatial Confinement ◽  
Light Emitting ◽  
Large Scale Production

AbstractWith rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.

scholarly journals High-speed high-efficiency large-area resonant cavity enhanced p-i-n photodiodes for multimode fiber communications

2001 ◽  
Vol 13 (12) ◽  
pp. 1349-1351 ◽  
Author(s):  
M. Gokkavas ◽  
O. Dosunmu ◽  
M.S. Unlu ◽  
G. Ulu ◽  
R.P. Mirin ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Resonant Cavity ◽  
Multimode Fiber ◽  
Large Area ◽  
Fiber Communications

scholarly journals Galaxy Evolution Studies with the SPace IR Telescope for Cosmology and Astrophysics (SPICA): The Power of IR Spectroscopy

2017 ◽  
Vol 34 ◽  
Author(s):  
L. Spinoglio ◽  
A. Alonso-Herrero ◽  
L. Armus ◽  
M. Baes ◽  
J. Bernard-Salas ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Formation Rate ◽  
Cosmic Time ◽  
Galactic Nuclei ◽  
Large Area ◽  
Radiation Fields ◽  
James Webb Space Telescope ◽  
Large Telescopes

AbstractIR spectroscopy in the range 12–230 μm with the SPace IR telescope for Cosmology and Astrophysics (SPICA) will reveal the physical processes governing the formation and evolution of galaxies and black holes through cosmic time, bridging the gap between the James Webb Space Telescope and the upcoming Extremely Large Telescopes at shorter wavelengths and the Atacama Large Millimeter Array at longer wavelengths. The SPICA, with its 2.5-m telescope actively cooled to below 8 K, will obtain the first spectroscopic determination, in the mid-IR rest-frame, of both the star-formation rate and black hole accretion rate histories of galaxies, reaching lookback times of 12 Gyr, for large statistically significant samples. Densities, temperatures, radiation fields, and gas-phase metallicities will be measured in dust-obscured galaxies and active galactic nuclei, sampling a large range in mass and luminosity, from faint local dwarf galaxies to luminous quasars in the distant Universe. Active galactic nuclei and starburst feedback and feeding mechanisms in distant galaxies will be uncovered through detailed measurements of molecular and atomic line profiles. The SPICA’s large-area deep spectrophotometric surveys will provide mid-IR spectra and continuum fluxes for unbiased samples of tens of thousands of galaxies, out to redshifts of z ~ 6.

scholarly journals Advanced Multilayer Composite Heavy-Oxide Scintillator Detectors for High Efficiency Fast Neutron Detection

2018 ◽  
Vol 170 ◽  
pp. 07010 ◽  
Author(s):  
Vladimir D. Ryzhikov ◽  
Sergei V. Naydenov ◽  
Thierry Pochet ◽  
Gennadiy M. Onyshchenko ◽  
Leonid A. Piven ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Count Rate ◽  
High Efficiency ◽  
Low Cost ◽  
Neutron Detection ◽  
Multilayer Composite ◽  
Large Area ◽  
Transparent Plastic ◽  
Fast Neutron Detection ◽  
Scintillator Detectors

We have developed and evaluated a new approach to fast neutron and neutron-gamma detection based on large-area multilayer composite heterogeneous detection media consisting of dispersed granules of small-crystalline scintillators contained in a transparent organic (plastic) matrix. Layers of the composite material are alternated with layers of transparent plastic scintillator material serving as light guides. The resulting detection medium – designated as ZEBRA – serves as both an active neutron converter and a detection scintillator which is designed to detect both neutrons and gamma-quanta. The composite layers of the ZEBRA detector consist of small heavy-oxide scintillators in the form of granules of crystalline BGO, GSO, ZWO, PWO and other materials. We have produced and tested the ZEBRA detector of sizes 100x100x41 mm and greater, and determined that they have very high efficiency of fast neutron detection (up to 49% or greater), comparable to that which can be achieved by large sized heavy-oxide single crystals of about Ø40x80 cm3 volume. We have also studied the sensitivity variation to fast neutron detection by using different types of multilayer ZEBRA detectors of 100 cm2 surface area and 41 mm thickness (with a detector weight of about 1 kg) and found it to be comparable to the sensitivity of a 3He-detector representing a total cross-section of about 2000 cm2 (with a weight of detector, including its plastic moderator, of about 120 kg). The measured count rate in response to a fast neutron source of 252Cf at 2 m for the ZEBRA-GSO detector of size 100x100x41 mm3 was 2.84 cps/ng, and this count rate can be doubled by increasing the detector height (and area) up to 200x100 mm2. In summary, the ZEBRA detectors represent a new type of high efficiency and low cost solid-state neutron detector that can be used for stationary neutron/gamma portals. They may represent an interesting alternative to expensive, bulky gas counters based on 3He or 10B neutron detection technologies.

Improving Contact and Passivation of Buried Interface for High‐Efficiency and Large‐Area Inverted Perovskite Solar Cells

2021 ◽  
pp. 2109968
Author(s):  
Xiaojia Xu ◽  
Xiaoyu Ji ◽  
Rui Chen ◽  
Fangyuan Ye ◽  
Shuaijun Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Perovskite Solar Cells ◽  
Large Area
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