A5021572518- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Heat and Mass Transfer in Porous Media
- Spacecraft and Cryogenic Technologies
- Heat Transfer and Boiling Studies
- Cellular and Composite Structures
- Embedded Systems Design Techniques
- Heat Transfer and Optimization
- Nuclear Physics and Applications
- Microfluidic and Capillary Electrophoresis Applications
- Radiation Effects in Electronics
- Spacecraft Design and Technology
- Advanced Thermodynamic Systems and Engines
- Laser-Plasma Interactions and Diagnostics
- Hydrocarbon exploration and reservoir analysis
- Heat Transfer Mechanisms
- Advanced Surface Polishing Techniques
- Drilling and Well Engineering
- Nuclear reactor physics and engineering
- Brake Systems and Friction Analysis
- Adhesion, Friction, and Surface Interactions
- Planetary Science and Exploration
- Lattice Boltzmann Simulation Studies
Los Alamos National Laboratory
2003-2023
Los Alamos National Security (United States)
2002
Seattle Epidemiologic Information and Research Center
2001
Many engineering applications require thermal cycling of granular materials. Since these materials generally have poor effective conductivity various techniques been proposed to improve bed transport. These include insertion metal foam with the material residing in interstitial space. The use introduces a parasitic capacitance, disrupts packing, and reduces amount active material. In order optimize combined high porosity foam-granular matrix study local nonequilibrium, multiple energy...
A simple model is developed here to predict the pressure drop and discharge coefficient for incompressible flow through orifices with length-to-diameter ratio greater than zero (orifice tubes) over wide ranges of Reynolds number. The orifice tubes represented as two drops in series; namely, a sharp-edged series developing straight length tube. Both these terms are using generally accepted correlations experimental data flows flow. We show agreement between this our numerical analysis laminar...
The team responsible for the design of Accelerator Production Tritium (APT) superconducting (SC) radio frequency (RF) power coupler has developed two 700-MHz, helium gas-cooled couplers. One a fixed inner conductor and other an adjustable (gamma prototype alpha prototype). couplers will be performance tested in near future. This paper discusses mechanical fabrication techniques employed development each coupler. includes material selection, copper coating, assembly sequences, metal joining...
Los Alamos has recently completed the latest in a series of Reconfigurable Software Radios, which incorporates several key innovations both hardware design and algorithms. Due to our focus on satellite applications, each must extract best size, weight, power performance possible from ensemble Commodity Off-the-Shelf (COTS) parts available at time design. A large component work lies determining if given part will survive space how it fail under various radiation conditions. Using two Xilinx...
For the new baseline APT (Accelerator Production of Tritium) linac design, power couplers are required to transmit 420 kW CW RF superconducting cavities at 700 MHz. These consist an airside waveguide-to-coax transition, air/vacuum break made by two planar, coaxial windows, and a vacuum-side antenna section. The allows adjustability matching cavities. Design, fabrication, testing coupler/window occurred over last four years, room temperature prototype design is complete. Coupler/window...
For the baseline APT (Accelerator Production of Tritium) linac design, power couplers are required to transmit 210-kW CW RF superconducting cavities. These operate at 700 MHz, have a coaxial design and an adjustable coupling Since May 1999, we been testing this on room-temperature test stand. We completed tests transmitted-power reflected-power conditions up 1 MW. also tested with portion outer conductor cooled by liquid nitrogen. Under latter condition, studied effects condensed gases...
High porosity metal foams have been the subject of many investigations for use in heat transfer enhancement through increased effective thermal conductivity and surface area. Convection applications with these investigated a large range Reynolds numbers. Common to analyses is need quantitative information about interfacial area foam. The well characterized, however little investigation has made into actual foam its dependence on pore density porosity. Three-dimensional x-ray computed...
Los Alamos has recently completed the latest in a series of reconfigurable software radios, which incorporates several key innovations both hardware design and algorithms. Due to our focus on satellite applications, each must extract best size, weight, power performance possible from ensemble commodity off-the-shelf (COTS) parts available at time design. In this case we have achieved 1 TeraOps/second signal processing 1920 Megabit/second datastream, while using only 53 Watts mains power, 5.5...
Geometric models are used to simplify the complex, three-dimensional geometry of metal foams for calculations effective thermal conductivity. The first is based on a conventional cubic lattice and second tetrakaidecahedronal model. consist interconnecting ligaments with spherical node at their intersections. foam determined two dimensionless parameters: 1) porosity 2) product specific surface area length ligaments. A free parameter represents size lumps ligament interconnections. It shown...
The flow of saturated liquid nitrogen through micro-scale orifices has been characterized experimentally. Measurements pressure drop and rate were made with flowing ranging in diameter from 50 micron to 370 micron, orifice length-to-diameter ratios 1.5 10. design the experimental apparatus, instrumentation used, uncertainties are presented. Obstacles encountered while attempting obtain repeatable reliable results at cryogenic temperatures discussed. Finally, experimentally measured discharge...
A curved rotating heat pipe for use in superconducting motor and generator applications is introduced here. The shown here built so that both the condenser evaporator sections are parallel to axis of rotation. section concentric with rotation while can be placed contact off-axis sources machine. geometry achieved by incorporating an S-shaped curve between on-axis revolving section. We show because a sealed, passive transfer device nearly isothermal operation, concept may advantageous when...
Superconducting radio frequency (SCRF) cavities are used in the high-energy portion of Accelerator Production Tritium (APT) linac to accelerate beam approximately 1700 MeV. To 100 mA proton and maintain field levels cavity, up 420 kW CW (continuous wave) 700-MHz RF power needs be delivered cavity. This is done using two window coupler assemblies that can each transmit 210 kW. evaluate developing window-coupler designs, a Room Temperature Test Bed (RTTB) has been built utilizes...
The Thermal Cycling Absorption Process (TCAP) Project at Los Alamos National Laboratory has been a collaborative effort with Savannah River Site to demonstrate the Tube-in-Tube (TnT) column design and improve TCAP science. TnT is an alternative which uses liquid thermally cycle metal hydride packed column. Inert gas displacement tests deuterium pulse have performed on inert are designed measure plug flow in while determine separation ability of A residual analyzer measures gases exit stream...
*† ‡ A test apparatus, that will be used to study the heat transfer performance of rotating pipes, has been designed and built. The apparatus allows for simultaneous testing a pair crank-shaped pipes operating near room temperature. rig is support with an on-axis condenser section, off-axis eccentrically evaporator curved adiabatic section. Due length (55”), distance from axis rotation section (9.5”), maximum speed (5500 rpm), care had taken in design substantial structure selection drive...
This paper describes the development progress of high current superconducting RF linacs in Los Alamos, performed to support a design linac for APT (Accelerator Production Tritium) Project. The includes CW energy section, spanning an range 211 1030 MeV, and operating at frequency 700 MHz with two constant beta sections (beta 0.64 0.82). In last years, we have progressed towards build cryomodule 0.64. We completed designs 5 cell cavities 210 kW power couplers. are scheduled begin assembly...
A high-field low-temperature superconducting solenoidal magnet was developed that is portable and can be operated in any orientation relative to gravity. The design consists of several features make this feasible; 1) bulk liquid cryogen storage occurs a separate Dewar rather than as part the assembly, which allows single-person transport due each component system having low weight, 2) vapor generated pressurization circulates cryogenic fluid from with flexible transfer lines allowing...
High-porosity, open-celled, metal foam has been utilized in several applications to enhance the surface area and effectively increase thermal conductivity of a bulk material. Analysis this multi-phase problem requires information about contact interfacial heat transfer coefficients multiple energy equation analysis. Since is dominant conductor combined matrix, boundary conductance limiting. This subject received little attention with investigations limited single parametric study lumped...