scholarly journals Laser-induced migration and isotope separation of epi-thermal monomers and dimers in supercooled free jets

2005 ◽  
Vol 23 (2) ◽  
pp. 225-253 ◽  
Author(s):  
JEFF W. EERKENS
Keyword(s):  
Kinetic Energy ◽  
Laser Beam ◽  
Low Temperatures ◽  
Laser Excitation ◽  
Vibrational Energy ◽  
Isotope Separation ◽  
Transport Parameters ◽  
Free Jets ◽  
Free Jet ◽  
Carrier Gases

Explicit relations are developed to estimate the outflux of migrating isotopomersiQF6to the outskirts of a supersonic supercooled free jet whose core is irradiated by a co-axial laser beam and intercepted by a skimmer that separates core gas from peripheral gases. The QF6target gas is diluted in carrier gas G (G = He, N2, Ar, Xe, SF6, etc.) which determines the jet's supersonic characteristics and forms QF6:G dimers at low temperatures. Under isotope-selective laser excitation, excitediQF6* convert their vibrational energy V into kinetic energy T after forming transientiQF6*:G dimers that dissociate in sub-microseconds. Three migrating groups with different transport parameters are created in the jet: thermal monomers, faster-moving epithermal monomers, and slower-moving dimers. Jet-core-fleeing QF6is enriched iniQF6due to enhanced outwards migration ofiQF6!epithermals and reduced escape ofjQF6:G dimers in the jet. Isotope enrichments in the rim gases are highest for heavier carrier gases such as G = Xe or G = SF6.

Laser excitation of BCl3 and consequential collision-induced reaction with carrier gases

2021 ◽  
pp. 138572
Author(s):  
Jing Guo ◽  
Ye-Jun Li ◽  
Jun-Ping Ma ◽  
Xian Tang ◽  
Xue-Shen Liu
Keyword(s):  
Laser Excitation ◽  
Carrier Gases ◽  
Induced Reaction

scholarly journals Double-Deck Metal Solenoids 3D Integrated in Silicon Wafer for Kinetic Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Nianying Wang ◽  
Ruofeng Han ◽  
Changnan Chen ◽  
Jiebin Gu ◽  
Xinxin Li
Keyword(s):  
Kinetic Energy ◽  
Power Density ◽  
Energy Harvester ◽  
High Efficiency ◽  
Vibrational Energy ◽  
Average Power ◽  
Wafer Level ◽  
Peak Voltage ◽  
Silicon Mold ◽  
Casting Technique

A silicon-chip based double-deck three-dimensional (3D) solenoidal electromagnetic (EM) kinetic energy harvester is developed to convert low-frequency (<100 Hz) vibrational energy into electricity with high efficiency. With wafer-level micro electro mechanical systems (MEMS) fabrication to form a metal casting mold and the following casting technique to rapidly (within minutes) fill molten ZnAl alloy into the pre-micromachined silicon mold, the 300-turn solenoid coils (150 turns for either inner solenoid or outer solenoid) are fabricated in silicon wafers for saw dicing into chips. A cylindrical permanent magnet is inserted into a pre-etched channel for sliding upon external vibration, which is surrounded by the solenoids. The size of the harvester chip is as small as 10.58 mm × 2.06 mm × 2.55 mm. The internal resistance of the solenoids is about 17.9 Ω. The maximum peak-to-peak voltage and average power output are measured as 120.4 mV and 43.7 μW. The EM energy harvester shows great improvement in power density, which is 786 μW/cm3 and the normalized power density is 98.3 μW/cm3/g. The EM energy harvester is verified by experiment to be able to generate electricity through various human body movements of walking, running and jumping. The wafer-level fabricated chip-style solenoidal EM harvesters are advantageous in uniform performance, small size and volume applications.

scholarly journals Thermochemical Nonequilibrium in Rapidly Expanding Flows of High-Temperature Air

1997 ◽  
Vol 52 (4) ◽  
pp. 358-368 ◽  
Author(s):  
Michio Nishida ◽  
Masashi Matsumotob
Keyword(s):  
High Temperature ◽  
Vibrational Energy ◽  
Stokes Equations ◽  
Computational Study ◽  
Mass Conservation ◽  
Navier Stokes ◽  
Tvd Scheme ◽  
Governing Equations ◽  
Navier Stokes Equations ◽  
Free Jet

Abstract • This paper describes a computational study of the thermal and chemical nonequilibrium occuring in a rapidly expanding flow of high-temperature air transported as a free jet from an orifice into low-density stationary air. Translational, rotational, vibrational and electron temperatures are treated separately, and in particular the vibrational temperatures are individually treated; a multi-vibrational temperature model is adopted. The governing equations are axisymmetric Navier-Stokes equations coupled with species vibrational energy, electron energy and species mass conservation equations. These equations are numerically solved, using the second order upwind TVD scheme of the Harten-Yee type. The calculations were carried out for two different orifice temperatures and also two different orifice diameters to investigate the effects of such parameters on the structure of a nonequilibrium free jet.

High‐rate growth at low temperatures by free‐jet molecular flow: Surface‐reaction film‐formation technology

1988 ◽  
Vol 52 (14) ◽  
pp. 1173-1175 ◽  
Author(s):  
T. Ohmi ◽  
M. Morita ◽  
T. Kochi ◽  
M. Kosugi ◽  
H. Kumagai ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Surface Reaction ◽  
Film Formation ◽  
High Rate ◽  
Molecular Flow ◽  
Free Jet ◽  
Flow Surface

Analysis of Laser Beam Propagation Effects in Atomic Laser Isotope Separation

1995 ◽  
Vol 34 (Part 1, No. 2A) ◽  
pp. 504-509 ◽  
Author(s):  
Yen-Wei Chen ◽  
Yasukazu Izawa ◽  
SadaoNakai ◽  
Chiyoe Yamanaka
Keyword(s):  
Laser Beam ◽  
Isotope Separation ◽  
Beam Propagation ◽  
Laser Beam Propagation ◽  
Propagation Effects ◽  
Laser Isotope Separation

Large Area Supersonic Jet Epitaxy of AlN, GaN, and SiC on Silicon

1996 ◽  
Vol 449 ◽  
Author(s):  
L.J. Lauhon ◽  
S. A. Ustin ◽  
W. Ho
Keyword(s):  
Supersonic Jet ◽  
X Ray Diffraction ◽  
Large Area ◽  
Free Jets ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Supersonic Jet Epitaxy ◽  
Carrier Gases

ABSTRACTAlN, GaN, and SiC thin films were grown on 100 mm diameter Si(111) and Si(100) substrates using Supersonic Jet Epitaxy (SJE). Precursor gases were seeded in lighter mass carrier gases and free jets were formed using novel slit-jet apertures. The jet design, combined with substrate rotation, allowed for a uniform flux distribution over a large area of a 100 mm wafer at growth pressures of 1–20 mTorr. Triethylaluminum, triethylgailium, and ammonia were used for nitride growth, while disilane, acetylene, and methylsilane were used for SiC growth. The films were characterized by in situ optical reflectivity, x-ray diffraction (XRD), atomic force microscopy (AFM), and spectroscopic ellipsometry (SE).

Evaluation of Turbulent Kinetic Energy Dissipation Rate in a Free Jet Flow from PIV Measurements

2012 ◽  
Vol 7 (1) ◽  
pp. 53-69
Author(s):  
Vladimir Dulin ◽  
Yuriy Kozorezov ◽  
Dmitriy Markovich
Keyword(s):  
Energy Dissipation ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Dissipation Rate ◽  
Energy Dissipation Rate ◽  
Turbulent Velocity ◽  
Small Scale ◽  
Velocity Fluctuations ◽  
Piv Measurements ◽  
Free Jet

The present paper reports PIV (Particle Image Velocimetry) measurements of turbulent velocity fluctuations statistics in development region of an axisymmetric free jet (Re = 28 000). To minimize measurement uncertainty, adaptive calibration, image processing and data post-processing algorithms were utilized. On the basis of theoretical analysis and direct measurements, the paper discusses effect of PIV spatial resolution on measured statistical characteristics of turbulent fluctuations. Underestimation of the second-order moments of velocity derivatives and of the turbulent kinetic energy dissipation rate due to a finite size of PIV interrogation area and finite thickness of laser sheet was analyzed from model spectra of turbulent velocity fluctuations. The results are in a good agreement with the measured experimental data. The paper also describes performance of possible ways to account for unresolved small-scale velocity fluctuations in PIV measurements of the dissipation rate. In particular, a turbulent viscosity model can be efficiently used to account for the unresolved pulsations in a free turbulent flow

scholarly journals Enabling remote quantum emission in 2D semiconductors via porous metallic networks

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jose J. Fonseca ◽  
Andrew L. Yeats ◽  
Brandon Blue ◽  
Maxim K. Zalalutdinov ◽  
Todd Brintlinger ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Laser Excitation ◽  
Single Photon ◽  
Photon Emission ◽  
Metal Films ◽  
Single Photon Emitters ◽  
2D Semiconductors ◽  
Exciton Recombination ◽  
Plasmon Polaritons ◽  
Dimensional Crystal

AbstractHere we report how two-dimensional crystal (2DC) overlayers influence the recrystallization of relatively thick metal films and the subsequent synergetic benefits this provides for coupling surface plasmon-polaritons (SPPs) to photon emission in 2D semiconductors. We show that annealing 2DC/Au films on SiO2 results in a reverse epitaxial process where initially nanocrystalline Au films gain texture, crystallographically orient with the 2D crystal overlayer, and form an oriented porous metallic network (OPEN) structure in which the 2DC can suspend above or coat the inside of the metal pores. Both laser excitation and exciton recombination in the 2DC semiconductor launch propagating SPPs in the OPEN film. Energy in-/out- coupling occurs at metal pore sites, alleviating the need for dielectric spacers between the metal and 2DC layer. At low temperatures, single-photon emitters (SPEs) are present across an OPEN-WSe2 film, and we demonstrate remote SPP-mediated excitation of SPEs at a distance of 17 μm.

Sign in / Sign up

Export Citation Format

Share Document