Windowless Configuration Research Articles

Preliminary design of a short-medium range windowless aircraft

This paper describes a new aircraft concept, where all windows, except those for emergency exits, are replaced with simulated windows, which consist of monitors connected to external cameras to overcome the discomfort for the passenger due to the absence of real windows. This concept is developed through an analytical method to estimate the potential advantages for the environment and for airline companies deriving from a windowless configuration for a short-medium range aircraft, within the boundaries of the preliminary design. Actually, the reduction in weight is directly linked to the reduction in fuel consumption, providing advantages in terms of operating costs and emissions of carbon dioxide. The method is applied to four models of short and medium range aircraft, namely Boeing 737–800, Airbus 320, ATR72 and Embraer 190. The results show the benefits of a windowless configuration that become very positive for the operating life of an aircraft and the total fleet, potentially leading to the saving of millions of tons of carbon dioxide every year when applied to the whole fleet of the analyzed aircraft.

In Situ Monitoring of the Anodic Reactions in Secondary Batteries By Transmission Electron Microscopy

Metal-ion, metal-sulfur, and metal-air batteries have recently attracted tremendous interests owing to their much higher gravimetric and volumetric energy densities as compared to conventional Li-ion batteries (LIBs). The metallic anodes employed in these next-generation batteries include Li, Na, Mg, Al, and Zn.1 So far, great effort has been devoted on the research of high-performance cathode materials. However, many technical issues associated with the metallic anodes such as dendritic growth, formation of passivation layer, as well as incomplete dissolution, have yet to be addressed. Moreover, the fundamental differences in the nature of these elements are far less exploited. To better understand the electrochemical behavior of metallic anodes, it is of importance to directly monitor their morphological and chemical evolution during the operation. There have been several attempts in developing new approaches toward this end over the past few years. In situ transmission electron microscopy (TEM) is expected to be a power tool for visualizing the dynamic processes of metallic anodes at a nanoscale.2,3 Most previous studies in this emerging field use a liquid cell with two silicon nitride windows to prevent vaporization of the electrolyte and involve demanding fabrication procedures. Besides, the presence of window materials largely reduces the image resolution. Take advantage of non-volatility of ionic liquids, herein, electrochemical behavior of metallic anodes was investigated by a specially designed window-less TEM holder. The miniature cell was composed of a counter electrode as the metal source, a modified TEM grid as the working electrode, and a sheet of IL-contained separator was hold between the electrodes. The cell was assembled in an Ar-filled glovebox and all the electrochemical measurements were conducted in the TEM chamber using a potentio/galvanostat. The typical images obtained are shown in Figure 1. In the instance of Li, three distinct types of deposits are identified (fiber, moss, film). It is worth mentioning that most of the Li microstructures reported essentially fall into these three categories, implying that our TEM results are representative of the actual electrodes. Majority of the deposits possess a fiber-like structure. These images are of good resolution and fairly consistent with the common dendrite morphology observed by ex situ SEM. With the help of window-less configuration, we can confirm that the deposits are fully covered with a thin solid electrolyte interphase (SEI) of a thickness of 10–20 nm. Furthermore, electron diffraction analysis is applicable for revealing the structural and compositional information of the deposits. These findings encourage us to further exploring other metallic anodes and comparing the features of each metal system. In summary, our approach provides possibilities to rapidly scrutinize the interface between the electrode and the non-volatile electrolyte, e.g., ionic liquid, glass- and ceramic-based electrolytes, for future secondary battery applications. Part of this research was supported by the Grant-in-Aid for Scientific Research, Grant Numbers 15H03591, 15K13287, and 15H2202 from the Japanese Ministry of Education, Culture, Sports, Science and Technology and by the ALCA-SPRING program, Japan Science and Technology Agency.

Design, construction, operation and performance of a Hadron Blind Detector for the PHENIX experiment

A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure CF 4 . It has a 50 cm long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.

Fourier-transform spectroscopy of HD in the vacuum ultraviolet at λ = 87–112 nm

Absorption spectroscopy in the vacuum ultraviolet (VUV) domain was performed on the hydrogen-deuteride molecule with a novel Fourier-transform spectrometer based upon wavefront division interferometry. This unique instrument, which is a permanent endstation of the undulator-based beamline DESIRS on the synchrotron SOLEIL facility, opens the way to Fourier-transform spectroscopy in the VUV range. The HD spectral lines in the Lyman and Werner bands were recorded in the 87–112 nm range from a quasi-static gas sample in a windowless configuration and with a Doppler-limited resolution. Line positions of some 268 transitions in the Lyman bands and 141 transitions in the Werner bands were deduced with uncertainties of 0.04 cm−1 (1σ) which correspond to Δλ/λ ∼ 4 × 10−7. This extensive laboratory database is of relevance for comparison with astronomical observations of H2 and HD spectra from highly redshifted objects, with the goal of extracting a possible variation of the proton-to-electron mass ratio (μ = m p /m e ) on a cosmological time scale. For this reason also calculations of the so-called sensitivity coefficients K i were performed in order to allow for deducing constraints on Δμ/μ. The K i coefficients, associated with the line shift that each spectral line undergoes as a result of a varying value for μ, were derived from calculations as a function of μ solving the Schrödinger equation using ab initio potentials.

A hadron blind detector for the PHENIX experiment at RHIC

A novel Hadron Blind Detector (HBD) has been developed for an upgrade of the PHENIX experiment at RHIC. The HBD will allow a precise measurement of electron-positron pairs from the decay of the light vector mesons and the low-mass pair continuum in heavy ion collisions. The detector consists of a 50 cm long radiator filled with pure CF4 and directly coupled in a windowless configuration to a triple Gas Electron Multiplier (GEM) detector with a CsI photocathode evaporated on the top face of the first GEM foil.

A hadron blind detector for the PHENIX experiment at RHIC

A Hadron Blind Detector (HBD) is being developed for the PHENIX experiment at RHIC. It consists of a Cherenkov radiator operated with pure CF 4 directly coupled in a windowless configuration to a triple-GEM detector element with a CsI photocathode and pad readout. The HBD operates in the bandwidth 6–11.5 eV (110–200 nm). We studied the detector response to minimum ionizing particles and to electrons. We present measurements of the CsI quantum efficiency, which are in very good agreement with previously published results over the bandwidth 6–8.3 eV and extend them up to 10.3 eV. Discharge probability and aging studies of the GEMs and the CsI photocathode in pure CF 4 are presented.

05/00802 An ideal window area concept for energy efficient integration of daylight and artificial light in buildings

Theoretical evidence is presented on the possibility that proper window sizing as well as proper selection of external surface to volume ratio can result in total energy savings for heating, cooling and lighting in the periphery zones of buildings. The savings are of the order of 50% relative to the windowless configuration. The optimum window are ranges from 10% to 40% of the wall area depending on the size and geometry of the spaces. The calculations were carried out for Austin, Texas using hourly weather data averaged over a 9 year period. The results of the calculations are strongly dependent on the sky illumination calculations. A model of the sky illumination that calculates the perceived intensity of illumination as a function of weather conditions and the orientation of the receptor relative to the sun is developed and the results of an empirical test run on the model are included.

Titania—a 1020W cm−2ultraviolet laser

The Titania laser system, based around a 42 cm e-beam pumped KrF amplifier, is currently being installed at the Rutherford Appleton Laboratory and will come on line as a user facility in 1996. Like Sprite, its predecessor, it will operate in both CPA (249 nm) and Raman (268 nm) short-pulse modes, delivering up to 10 TW to target in high-quality beams. With brightness expected to reach 10 21 W cm -2 sterad -1 , it will be the world's brightest ultraviolet laser. The design of the Titania system includes a number of novel features. The multi-pass Ti :sapphire front-end amplifier uses an unusual beam-folding scheme. The Raman system will involve the first application of Raman multiplexing, combining high KrF efficiency with low transport cost. Reflective coatings with very high damage thresholds are being developed for the CPA compressor gratings and the UV transport optics. A windowless configuration for the final Raman amplifier is presently under analysis, to allow the performance of this maximally stressed component to be extended substantially. Finally the design of the Titania e-beam machine, featuring novel split-cathode diodes, has resulted in unusually high efficiency of electron transport into the laser gas. The laser's infrastructure has involved sophisticated mechanical and electrical design, and a computerized diagnostic, control and safety package is being developed to allow one-man operation of the whole 1000 m 2 installation.

Wide area windowless disk plasma lamp of uniform intensity for use in microelectronic film processing

A wide area windowless plasma disk excited by a soft vacuum electron beam provides a wide area uniform source of vacuum ultraviolet (VUV) photons as well as atomic radicals. Hydrogen and oxygen when excited by the soft vacuum electron beam, emit strong atomic resonance radiation at 121.6 and 130 nm, respectively; in fact up to 8% of the total applied discharge power is emitted as VUV photons. The spatial uniformity of the atomic VUV resonance radiation approaches 6% across a disk 19 cm in diameter. The density of atomic oxygen species generated in the plasma disk has also been experimentally determined using an established polymer film etch rate method as well as with a conventional silver thin film sensor. We employ the disk plasma in a windowless configuration to achieve lower temperature chemical vapor deposition (CVD) than conventional thermal CVD. The VUV photon flux as well as the radical and excited atomic gas species emitted from the lamp can assist dissociation of feedstock reactant gases as well as assist heterogeneous surface reactions and increase surface mobility of absorbed species allowing for lower temperature CVD. Thin films of an aluminum nitride and hydrogenated amorphous silicon have been deposited at temperature between 100–400 °C. The deposited films show improvement over other plasma and photo-assisted CVD processes in the film quality achieved, the area covered, the substrate temperature required, and the maximum deposition rates that are possible. In situ generation of arsine (AH3) and unsaturated arsenic hydrides AsHx (x≤2) have also been achieved by placing elemental arsenic in an environment rich in atomic hydrogen created from the disk–plasma source.

Day lighting as a factor in optimizing the energy performance of buildings

Theoretical evidence is presented on the possibility that proper window sizing as well as proper selection of external surface to volume ratio can result in total energy savings for heating, cooling and lighting in the periphery zones of buildings. The savings are of the order of 50% relative to the windowless configuration. The optimum window are ranges from 10% to 40% of the wall area depending on the size and geometry of the spaces. The calculations were carried out for Austin, Texas using hourly weather data averaged over a 9 year period. The results of the calculations are strongly dependent on the sky illumination calculations. A model of the sky illumination that calculates the perceived intensity of illumination as a function of weather conditions and the orientation of the receptor relative to the sun is developed and the results of an empirical test run on the model are included.

Miniature Photomultiplier for Scintillation and Space Use

A rugged miniature photomultiplier has been developed which is only 8 mm in diameter. The electron multiplying element is a single channel multiplier. Photoelectrons from the 5 mm diameter cathode are electrostatically focused into the channel multiplier without need for a funnel or cathode-to-channel bias. This photomultiplier is a two-terminal device and uses no external resistors. The high gain characteristics (~108 at 3,000V), and the single-electron pulse height distribution (FWHM ⩽0.6), make the tube ideal for pulse-counting applications. The small diameter of this tube suggests applications in close-packed arrays and mosaics for scintillation imaging. This tube can be used as a scintillation spectum analyzer with good resolution even at high gains where there are greater than 109 anode electrons per scintillation event. The structure can also be employed in a windowless configuration as a particle or x-ray detector. In this modification apertures as large as 5 × 7 mm2 are possible. One use is as the detector in an Auger apparatus, where the high-gain output pulses allow precision digital data handling techniques and long drift-free integration time.