Microwave Sintering: Initial Scale-up for Lunar Landing and Launch Pad Construction
No abstract provided
Bahr, Curtis W.↗
Engineering topics
Barmatz, Martin B.
Publications and source records attributed to Barmatz, Martin B..
Basis of Creating a Microwave-Based Construction System for the Moon
No abstract provided
Shulman, Holly S.↗
Technique for Performing Dielectric Property Measurements at Microwave Frequencies
A method, system, apparatus, and computer readable medium has been provided with the ability to obtain a complex permittivity dielectric or a complex permeability micron of a sample in a cavity. One or more complex-valued resonance frequencies f(sub m) of the cavity, wherein each f(sub m) is a measurement, are obtained. Maxwell's equations are solved exactly for dielectric, and/or micron, using the f(sub m) as known quantities, thereby obtaining the dielectric and/or micron of the sample.
Barmatz, Martin B.↗
Method for Processing Lunar Regolith Using Microwaves
A paper describes a method of using microwave heating experiments on lunar simulants to determine the mechanism that causes lunar regolith to be such an excellent microwave absorber. The experiments initially compared the effects of sharp particle edges to round particle edges on the heating curves. For most compositions, sharp particle edged samples were more effective in being heated by microwaves than round particle edged materials. However, the experiments also showed an unexpected effect for both types of particles. Upon heating the sample surface above 400 C, the sample experienced some sort of internal structure change that caused it to heat much more efficiently. This enhancement may be associated with the unique microwave volumetric heating that can produce a large temperature gradient within the sample leading to melting of some components at the center of the sample. This new effect that may also be happening in lunar regolith samples is probably the cause of the previously observed enhanced heating of a sample of lunar regolith. Properly designed microwave applicators could heat and solidify the lunar regolith to form roads and building blocks for structures needed on the Moon
Barmatz, Martin B.↗
Microwave Sinterator Freeform Additive Construction System (MS-FACS)
The harmful properties of lunar dust, such as small size, glass composition, abnormal surface area, and coatings of imbedded nanophase iron, lead to a unique coupling of the dust with microwave radiation. This coupling can be exploited for rapid sintering of lunar soil for use as a construction material that can be formed to take on an infinite number of shapes and sizes. This work describes a system concept for building structures on the lunar surface using lunar regolith (soil). This system uses the ATHLETE (All-Terrain Hex- Limbed Extra-Terrestrial Explorer) mobility system as a positioning system with a microwave print head (similar to that of a smaller-scale 3D printer). A processing system delivers the lunar regolith to the microwave print head, where the microwave print head/chamber lays down a layer of melted regolith. An arm on the ATHLETE system positions the layer depending on the desired structure.
Howe, Alan S.↗
Exact Cavity Perturbation Technique to Determine Complex Permittivity of Dielectric Materials
Cassini is an international spacecraft mission facilitated by NASA and ESA which seeks to understand the Saturn planetary system, including rings and moons. Launched in 1997, the Cassini spacecraft contains two major components: the Cassini orbiter that has been orbiting Saturn since October 2004, and the European-built Huygens probe that landed on Titan's surface in December 2004 to study its geology and atmosphere. Titan, Saturn's largest moon and the second largest moon in the solar system, possesses surface and atmospheric features similar to those of Earth, including lakes, seas, and mountains. A physical characterization of these features is critical to understanding the origin and evolution of Titan, whose surface composition reflects its geological history. Because Titan's atmosphere is largely composed of methane, it is believed that surfaces lakes are filled with mixtures of liquid hydrocarbons. The Cassini orbiter's RADAR instrument has been scanning Titan's surface at the atmosphere-penetrating microwave frequency of 13.8 Gigahertz since 2004. However, accurate interpretation of these data is limited by a lack of knowledge regarding dielectric properties of liquid hydrocarbons at cryogenic temperatures. Therefore, it is of specific interest to experimentally determine values for the complex permittivities of various liquid hydrocarbon mixtures at the surface conditions of Titan. In particular, more accurate values for complex permittivity would improve estimates of lake depth and surface composition obtained from the instrument's altimetry and backscatter modes.
dielectric constant↗
Technique for Performing Dielectric Property Measurements at Microwave Frequencies
A paper discusses the need to perform accurate dielectric property measurements on larger sized samples, particularly liquids at microwave frequencies. These types of measurements cannot be obtained using conventional cavity perturbation methods, particularly for liquids or powdered or granulated solids that require a surrounding container. To solve this problem, a model has been developed for the resonant frequency and quality factor of a cylindrical microwave cavity containing concentric cylindrical samples. This model can then be inverted to obtain the real and imaginary dielectric constants of the material of interest. This approach is based on using exact solutions to Maxwell s equations for the resonant properties of a cylindrical microwave cavity and also using the effective electrical conductivity of the cavity walls that is estimated from the measured empty cavity quality factor. This new approach calculates the complex resonant frequency and associated electromagnetic fields for a cylindrical microwave cavity with lossy walls that is loaded with concentric, axially aligned, lossy dielectric cylindrical samples. In this approach, the calculated complex resonant frequency, consisting of real and imaginary parts, is related to the experimentally measured quantities. Because this approach uses Maxwell's equations to determine the perturbed electromagnetic fields in the cavity with the material(s) inserted, one can calculate the expected wall losses using the fields for the loaded cavity rather than just depending on the value of the fields obtained from the empty cavity quality factor. These additional calculations provide a more accurate determination of the complex dielectric constant of the material being studied. The improved approach will be particularly important when working with larger samples or samples with larger dielectric constants that will further perturb the cavity electromagnetic fields. Also, this approach enables the ability to have a larger sample of interest, such as a liquid or powdered or granulated solid, inside a cylindrical container.
Barmatz, Martin B.↗
Development of a Microwave Facility for Processing Lunar Regolith
This viewgraph presentation reviews in this Roadmap for Developing a Lunar Microwave Facility an approach to determine the source of the enhanced microwave heating of Lunar Regolith. A set of microwave heating studies were proposed for a specially designed realistic simulant to determine optimum processing parameters. Apollo lunar soil will be used to validate the heating features found for the simulant. We have also introduced several possible designs for a future lunar microwave processing facility. In the future when sufficient funds become available, a microwave facility for processing regolith on the lunar surface will be ready to be built
microwave processing↗
Microwave bonding of MEMS component
Bonding of MEMs materials is carried out using microwave. High microwave absorbing films are placed within a microwave cavity, and excited to cause selective heating in the skin of the material. This causes heating in one place more than another. Thereby minimizing the effects of the bonding microwave energy.
Barmatz, Martin B.↗
Microwave bonding of thin film metal coated substrates
Bonding of materials such as MEMS materials is carried out using microwaves. High microwave absorbing films are placed within a microwave cavity containing other less microwave absorbing materials, and excited to cause selective heating in the skin depth of the films. This causes heating in one place more than another. This thereby minimizes unwanted heating effects during the microwave bonding process.
Barmatz, Martin B.↗
Chemical vapor deposition coating of fibers using microwave application
Chemical vapor deposition coating is carried out in a cylindrical cavity. The fibers are heated by a microwave source that is uses a TM0N0 mode, where O is an integer, and produces a field that depends substantially only on radius. The fibers are observed to determine their heating, and their position can be adjusted. Once the fibers are uniformly heated, a CVD reagent is added to process the fibers.
Barmatz, Martin B.↗
Uniform batch processing using microwaves
A microwave oven and microwave heating method generates microwaves within a cavity in a predetermined mode such that there is a known region of uniform microwave field. Samples placed in the region will then be heated in a relatively identical manner. Where perturbations induced by the samples are significant, samples are arranged in a symmetrical distribution so that the cumulative perturbation at each sample location is the same.
Barmatz, Martin B.↗
Method and apparatus for selectively annealing heterostructures using microwaves
The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.
Atwater, Harry A.↗
Microwave Brazing of TSP Diamond Drill Bit Cutters
Explore the source record for details and available documents.
microwave heating Diamond (TSP) brazing drill bit ↗
Method and apparatus for selectively annealing heterostructures using microwave
The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.
Atwater, Harry A.↗
Measuring Q And f(sub r) Of A Microwave Cavity: Part I
Method of measuring quality factor (Q) and frequency of resonance (f(subr)) of microwave cavity exploits two inflection points of power-vs.-frequency resonance curve of cavity. Intended particularly for use with microwave cavity in which sample of lossy dielectric material heated to specified high temperature by microwave power at resonant frequency. Accurate measurement contributes to enhanced monitoring and control in contactless high-temperature processing of materials. Also used with small spherical sample to determine temperature dependence of complex dielectric constant.
Barmatz, Martin B.↗
Measuring Q And f(sub r) Of A Microwave Cavity: Part II
Frequency maintained at f(sub r), and Q determined from decay-rate measurement. Like "Measuring Q and f(sub r) of a Microwave Cavity: Part I" (NPO-19101), method used with microwave cavity in which sample of lossy dielectric material heated to specified high temperature by microwave power at resonant frequency. Methods contribute to accurate measurement of Q and f(sub r) for enhanced monitoring and control in contactless high-temperature processing of materials. Present method more effective in maintaining constant temperature. Also implemented more simply and at lower cost.
Iny, Ofer↗
Computing Microwave Force Via Boltzmann-Ehrenfest Principle
Report describes first application of Boltzmann-Ehrenfest principle of adiabatic invariance to prediction of restoring force on dielectric sphere levitated in microwave resonant cavity in absence of gravitation.
Mcdonough, Colleen C.↗