Strong evaporation of a laser-heated water aerosol droplet

The results of lead ion generation with charge state from Pb10+ to Pb35+ from laser-heated plasma are presented. CO2 lasers producing 10.6-μm wavelength radiation at power densities in the range 4.1011-6.1014 W/cm2 in TBKI and CERN were used. Results of detailed numerical simulations presented in the paper are in good agreement with the experimental data. Work done in collaboration with CERN, ITEP, and TBKI was aimed at the specification of requirements for a laser system that will be able to drive an ion source for the hadron collider (LHC) at CERN.

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Laser Floating Zone Growth: Overview, Singular Materials, Broad Applications, and Future Perspectives

Crystals ◽

10.3390/cryst11010038 ◽

2020 ◽

Vol 11 (1) ◽

pp. 38

Author(s):

Francisco Rey-García ◽

Rafael Ibáñez ◽

Luis Alberto Angurel ◽

Florinda M. Costa ◽

Germán F. de la Fuente

Keyword(s):

Equilibrium Phase ◽

Polycrystalline Materials ◽

Floating Zone ◽

High Crystalline Quality ◽

Experimental Parameters ◽

Phase Selectivity ◽

Oriented Polycrystalline ◽

Laser Heated ◽

Lfz Technique ◽

Zone Growth

The Laser Floating Zone (LFZ) technique, also known as Laser-Heated Pedestal Growth (LHPG), has been developed throughout the last several decades as a simple, fast, and crucible-free method for growing high-crystalline-quality materials, particularly when compared to the more conventional Verneuil, Bridgman–Stockbarger, and Czochralski methods. Multiple worldwide efforts have, over the years, enabled the growth of highly oriented polycrystalline and single-crystal high-melting materials. This work attempted to critically review the most representative advancements in LFZ apparatus and experimental parameters that enable the growth of high-quality polycrystalline materials and single crystals, along with the most commonly produced materials and their relevant physical properties. Emphasis will be given to materials for photonics and optics, as well as for electrical applications, particularly superconducting and thermoelectric materials, and to the growth of metastable phases. Concomitantly, an analysis was carried out on how LFZ may contribute to further understanding equilibrium vs. non-equilibrium phase selectivity, as well as its potential to achieve or contribute to future developments in the growth of crystals for emerging applications.

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Characteristics of Extratropical Cyclones That Cause Tornadoes in Italy: A Preliminary Study

Atmosphere ◽

10.3390/atmos12020180 ◽

2021 ◽

Vol 12 (2) ◽

pp. 180

Author(s):

Eigo Tochimoto ◽

Mario Marcello Miglietta ◽

Leonardo Bagaglini ◽

Roberto Ingrosso ◽

Hiroshi Niino

Keyword(s):

Environmental Conditions ◽

Convective Available Potential Energy ◽

Static Stability ◽

Extratropical Cyclones ◽

Cool Season ◽

Southeastern Us ◽

Different Seasons ◽

The Difference ◽

Upper Level ◽

Strong Evaporation

Characteristics of extratropical cyclones that cause tornadoes in Italy are investigated. Tornadoes between 2007 and 2016 are analyzed, and statistical analysis of the associated cyclone structures and environments is performed using the JRA-55 reanalysis. Tornadoes are distributed sporadically around the cyclone location within a window of 10° × 10°. The difference in the cyclone tracks partially explains the seasonal variability in the distribution of tornadoes. The highest number of tornadoes occur south of the cyclone centers, mainly in the warm sector, while a few are observed along the cold front. Composite mesoscale parameters are examined to identify the environmental conditions associated with tornadoes in different seasons. Potential instability is favorable to tornado development in autumn. The highest convective available potential energy (CAPE) in this season is associated with relatively high-temperature and humidity at low-levels, mainly due to the strong evaporation over the warm Mediterranean Sea. Upper-level potential vorticity (PV) anomalies and the associated cold air reduce the static stability above the cyclone center, mainly in spring and winter. On average, the values of CAPE are lower than for US tornadoes and comparable with those occurring in Japan, while storm relative helicity (SREH) is comparable with US tornadoes and higher than Japanese tornadoes, indicating that the environmental conditions for Italian tornadoes have peculiar characteristics. Overall, the conditions emerging in this study are close to the high-shear, low-CAPE environments typical of cool-season tornadoes in the Southeastern US.

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Transient Temperature During the Vaporization of Liquid on a Pulsed Laser-Heated Solid Surface

Journal of Heat Transfer ◽

10.1115/1.2822689 ◽

1996 ◽

Vol 118 (3) ◽

pp. 702-708 ◽

Cited By ~ 24

Author(s):

H. K. Park ◽

X. Zhang ◽

C. P. Grigoropoulos ◽

C. C. Poon ◽

A. C. Tam

Keyword(s):

Thin Film ◽

Solid Surface ◽

Elevated Temperatures ◽

Bubble Nucleation ◽

Transient Temperature ◽

Specular Reflectance ◽

Transient Temperature Field ◽

Excimer Laser Pulse ◽

Nanosecond Time Resolution ◽

Laser Heated

The thermodynamics of the rapid vaporization of a liquid on a solid surface heated by an excimer laser pulse is studied experimentally. The transient temperature field is measured by monitoring the photothermal reflectance of an embedded thin film in nanosecond time resolution. The transient reflectivity is calibrated by considering a temperature gradient across the sample based on the static measurements of the thin film optical properties at elevated temperatures. The dynamics of bubble nucleation, growth, and collapse is detected by probing the optical specular reflectance. The metastability behavior of the liquid and the criterion for the onset of liquid–vapor phase transition in nanosecond time scale are obtained quantitatively for the first time.

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