Window Assembly Research Articles

Replaceable Be and Al windows for X-ray beam lines

Construction details and results of on-going performance tests are presented for two ultrahigh vacuum compatible, free-convection cooled window assemblies in which the window disk is easily replaceable. In the Be window assembly, an 0.25 mm thick Be disk, 38 mm in diameter, is sealed into a stainless steel adapter flange using 0.5 mm diameter pure Al wire. The assembly is leak tight to better than 1 × 10 −10 atm cm 3/s before and after multiple bakeouts to 250°C. However, an unexplained temperature-dependent He leak, with a maximum magnitude in the low 10 −10 atm cm 3/s range at 250°C, appears during bakeout. Possible causes for this leak are discussed. In the Al window assembly, a 25 μm thick Al disc, 60 mm in diameter, acts as the sealing medium as well as the window material over a 10 mm × 50 mm opening. This assembly remains leak tight to better than 1 × 10 −10 atm cm 3/s throughout multiple bakeouts to 150°C and has been successfully tested in white and monochromatic beam lines at the NSLS X-ray ring.

A simple and versatile ultrahigh vacuum leak-tight infrared window assembly

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Fire tests on window assemblies protected by automatic sprinklers

Full-scale fire tests on wired and tempered glazing in steel and aluminum frames are described. These assemblies achieved fire resistance ratings when exposed to a standard fire of 45 min to 2 h. The maximum radiant heat flux transmitted through the glass was reduced by more than 90%.

Recent research related to the development of electrochromic windows

The results of recent research on each of the layers of a solid-state multilayer structure for electrochromic windows are reviewed. This includes a review of the requirements of the multilayer structure for building windows and especially the need to have an electrochemically balanched system. The results indicate that excess free electron scattering in polycrystalline WO 3 films (the electrochromatic layer) is not only the source of lower than desired reflectivity modulation, but it is also the major source of higher than desired absorptivity modulation. Research on LiAlF 4 indicates that it is a viable candidate for the ion conducting layer, being a good lithium ion conductor and a good electronic insulator. Finally, we have recently discovered that tin-doped and undoped In 2O 3 films are mixed conductors, exhibiting lithium ion injection/extraction. This is significant since such films could possibly serve in the dual capacity of counterelectrode and transparent conductor, thereby reducing the complexity, the technical problems, and the cost of electrochromic window assemblies.

Front ends for the Photon Factory beam lines

The front end of each beam line at Photon Factory serves the experimental area with a synchrotron radiation beam of 30 mrad in horizontal aperture. Some specific aspects concerning an acoustic delay line, a fast closing valve, silicon carbide mirrors and a beryllium window assembly installed in the beam lines are presented.

Performance characteristics of high power, multiple gun, electrocurtains ®

Electron processors are power limited electrically, usually due to the inability of the vacuum window assembly to dissipate the energy absorbed from the primary beam above a certain flux level. This problem is accentuated at low operating voltages typical of selfshielded processors, where the characteristic stopping power of the electron in the window material may be very high. Practical window geometries are discussed which are capable of current ratings of up to 0.4 mA cm 2 at 200 keV. Under these operating conditions, a single window unit can deliver 1 megarad at line speeds of up to 600 m/minute (2000 fpm). For most electron initiated processes, the lowest average dose rate achievable in the process zone is desirable. For products requiring a high treatment level (e.g. dose to cure), it is often desirable to extend the process zone so that the high delivered dose can be achieved without resorting to very high dose rates. A processor geometry is described which incorporates two or more Electrocurtain units in tandem. Typical performance data for these EPZ (Extended Process Zone) units are presented showing depth: dose performance, edge:edge uniformity of ±3%, and dose delivered as a function of output current. For a typical three element processor, 1 megarad can be delivered at 1500 meters/minute at processor voltages in the 150–300 keV range. The behavior of the surface dose fall-off with increasing operating voltage due to stopping power variation is discussed.

Calcium fluoride window mounting

A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

Heat mirror coatings for energy conserving windows

Heat-mirror coatings are important as transparent insulation for a host of applications, including building window glazings. They reduce thermal emittance of glass and polymeric substrates, thereby decreasing the effective radiative loss of a glazing or window assembly. Properties of coatings and substrates, as well as various window designs, are detailed. The paper reviews heat-mirror deposition technology including chemical vapor deposition using hydrolysis and pyrolysis reactions, dc and rf sputtering using reactive, biased and nonreactive techniques, vapor deposition and ion plating. The properties of single-layer films including coatings of In 2O 3:Sn, doped SnO 2, Cd 2SnO 4, noble and transition metal films are enumerated. Multilayer films described include dielectric overcoated metals such as ZnS/metal/ZnS, Bi 2O 3/Au/Bi 2O 3 and TiO 2/Ag/TiO 2. Electrical, solar and infrared radiative properties are tabulated. Much of the data presented is also useful for photovoltaic and collector applications. New and innovative materials systems are suggested.

Noise‐insulation requirements for multi‐family dwellings

Noise insulation standards are part of the California Administrative Code (Title 25, Section 1092). These standards apply to all new multi‐family dwelling units such as hotels, apartments, duplexes, townhouses, and condominium units. Detached single‐family dwellings are specifically excluded. The standards establish minimum requirements for the isolation of interior spaces from exterior noise and set minimum ratings for noise insulation of partitions between dwelling units. A community noise equivalent level (CNEL) of 45 dB is set as the maximum for intrusive noise from exterior sources such as rail or road traffic, or aircraft operations. American Society for Testing and Materials (ASTM) testing procedures for party wall and floor/ceiling system sound transmission provide the basis for setting minimum acceptable performance for separations between units. As a consultant to builders, planners, and architects, the site planning and design of residential projects have been examined and field evaluations have been performed on completed projects. Building designs and the selection of suitable building elements (wall construction composites, window assemblies, vent configurations, etc.) which assure compliance with the standards have been identified. The paper provides a brief description of the standards, their enforcement pitfalls, and an assessment of their impact on residential construction in California.

3789. Visible-infrared window assembly for ultra-high vacuum systems. (USA): P E Wierenga et al,Rev scient Instrum, 49 (3), 1978, 408

3789. Visible-infrared window assembly for ultra-high vacuum systems. (USA): P E Wierenga et al,Rev scient Instrum, 49 (3), 1978, 408

Visible-infrared window assembly for ultrahigh vacuum systems

A window assembly for ultrahigh vacuum systems is described which uses Irtran 4 visible-infrared transmitting optical material. The assembly is made in a standard ultrahigh vacuum flange. The window is sealed in place with Pyroceram. The assembly can be repeatedly heat-cycled up to 200 degrees C without failure.

Deep Submergence Spherical Shell Window Assembly With Glass or Transparent Ceramic Windows for Abyssal Depth Service

A total of 20 spherical shell windows with R0 = 4 in., Ri = 3 in., and 150 deg included spherical angle have been pressure tested under static and dynamic loading conditions. The tests included not only long term cyclic tests at 4500, 9000, 13,500, and 20,000 psi but also underwater shock tests at 450 psi static pressure. Two different gasket and four different transparent window materials were tested in the same metallic window flange with plane bearing surface. The transparent materials used in windows were glass ceramic CERVIT C-101, chemically surface compressed glass CERVIT SSC-201, borosilicate crown glass BK-7, and Plexiglas G acrylic plastic. The test results based on a total of over 10,000 hr of pressure testing indicate that the NUC 150 deg spherical shell window assembly design with t/Ri = 0.333 windows described in this paper can be routinely used in unmanned systems to any depth found in the ocean providing that the chemically surface compressed glass or transparent ceramic materials evaluated in this study are used in the assembly.

Multiple Docking Adapter Window for the S-190 Experiment

Martin Marietta/NASA subcontracted the design, fabrication, testing, and installation of the multiple docking adapter S-190 experiment window assembly to Actron. In this paper we primarily treat the thermal-optical analysis aspect of the design phase. The window is a pane of BK 7 glass 59.18 cm x 44.91 cm x 4.06 cm. Though it must meet many mechanical specifications, the optical requirements, dictated by the high acuity, distortion-free S-190 multiband camera system, are the most severe. Under operating conditions over any 7.6-cm circular area, the maximum rms deviation from the best-fitting plane must be less than 12.0 nm, and from the reference plane through the entire window, 60.0 nm.

A new compact soft X-ray gas flow proportional counter

This instrument comprises an X-ray detector and built-in preamplifier. It is easily demountable, giving ready access to the anode wire and electronic components, and has a window assembly which permits thin plastic windows to be mounted in a convenient manner. The anode wire is held in a simple novel arrangement, which allows it to be replaced easily. The instrument operates efficiently inside a vacuum, and its compact dimensions make it especially attractive for use within an X-ray spectrometer.

A consideration of the advantages offered by a new stainless steel support grid in a proportional counter window assembly

This account describes how a recently developed stainless steel grid offers considerable advantages when used in a proportional counter to support a thin window.

An Infrared Window Assembly for Ultrahigh Vacuum Systems

A simple compact window assembly for ultrahigh vacuum systems is described which uses Irtran 2 or Irtran 6 ir transmitting optical material. The assembly is made in a standard ultrahigh vacuum flange using commercially available components. The window is sealed in place with silicone resin. After curing, the assembly can be repeatedly heat cycled up to 200°C without failure.

An ultra-violet transmitting window for image tubes

A sealed window assembly suitable for the photocathode of image tubes is described. Essential features are optical quality, ultra-violet transmission and good electrical continuity.

Filament Furnace for Microscopy Studies at High Temperatures

A filament furnace is described which is suitable for heating gram quantities of materials to 3000°C under reduced pressures or in various atmospheres. A quartz window and shutter assembly permit the observation of the specimen during the heating cycle by long working distance microscopes.

Mica Window Assembly for Use at Elevated Bake-Out Temperatures

Mica Window Assembly for Use at Elevated Bake-Out Temperatures