Pulsed‐laser optogalvanic spectroscopy of sodium and scandium in a high‐pressure metal halide discharge

1988 ◽  
Vol 64 (6) ◽  
pp. 2934-2941 ◽  
Author(s):  
Jerry Kramer
Keyword(s):  
High Pressure ◽  
Pulsed Laser ◽  
Metal Halide ◽  
Optogalvanic Spectroscopy

Features of metal destruction under pulse laser and beam-plasma exposure

2020 ◽  
Vol 10 ◽  
pp. 34-47
Author(s):  
V. A. Gribkov ◽  
◽  
S. V. Latyshev ◽  
V. N. Pimenov ◽  
S. A. Maslayev ◽  
...  
Keyword(s):  
High Pressure ◽  
Laser Radiation ◽  
Solid Phase ◽  
Ion Beam ◽  
Pulsed Laser ◽  
Average Energy ◽  
Destructive Effect ◽  
Pulsed Laser Radiation ◽  
Beam Plasma ◽  
Metal Materials

The features of the destructive effect of high-pressure generated under comparable conditions, namely, upon irradiation of target samples with pulsed laser radiation and beam-plasma flows created in Plasma Focus (PF) devices, on metal materials were studied. In both cases, close parameters of radiation-heat treatment were provided: power density q ~ 1010–1011 W/cm2 and pulse duration τ ~ 10 –100 ns. It have been shown that the double exposure of laser radiation to thin samples of vanadium and molybdenum with a thickness of 0.3 mm and 0.1 mm, respectively, leads to the formation of molten zones in the materials, inside which there were deep craters. The craters extended over the entire thickness of the samples, on the reverse side of which the recesses end with holes of ~ 0.1 mm for V and 0.2 mm for Mo. In a tungsten sample 0.2 mm thick, the depth of the craters in the molten zone was less than its thickness and there were microcracks on the back of the sample. Based on numerical estimates of the process under study, it was suggested that the observed effects are associated with the creation of high pressure zones of ~ 1 – 10 GPa in the irradiated targets, localized in microregions of radius r ~ 0.1 mm. In these zones, the behavior of the solid phase of the target materials, for which the tensile strength σB ≤ 1 GPa (V, Mo, W), under high pressure became close to the behavior of the liquid. The pseudo-liquid phase of the material was displaced from the center of the crater, where the pressure was maximum, to its periphery to the region of low pressure with the subsequent release of matter from the target through the irradiated surface at a speed of ~ 103 m/s. In experiments using the PF, the mechanism responsible for the formation of craters when a powerful pulsed laser radiation is applied to the target is not realized due to the different nature of the distribution of the absorbed energy density in the surface layer of the irradiated sample. The region in which the energy absorbed during the of particles implantation into the material was determined mainly by the average energy and the diameter of the ion beam (Еi ≈ 100  keV, d ~ 2 – 10 mm) and exceeds by one or two orders of magnitude the corresponding volume under laser irradiation.

Structural regulation and optical behavior of three-dimensional metal halide perovskites under pressure

2020 ◽  
Vol 8 (37) ◽  
pp. 12755-12767
Author(s):  
Yue Shi ◽  
Yu Zhou ◽  
Zhiwei Ma ◽  
Guanjun Xiao ◽  
Kai Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Metal Halide ◽  
Structural Regulation ◽  
Halide Perovskites ◽  
Optical Behavior

The high-pressure behaviors of three-dimensional (3D) metal halide perovskites (MHPs) have been summarized in this “scientific dictionary”.

UV-B response of cucumber seedlings grown under metal halide and high pressure sodium/deluxe lamps

1993 ◽  
Vol 88 (2) ◽  
pp. 350-358 ◽  
Author(s):  
Donald T. Krizek ◽  
George F. Kramer ◽  
Abha Upadhyaya ◽  
Roman M. Mirecki
Keyword(s):  
High Pressure ◽  
Metal Halide ◽  
Cucumber Seedlings

The influence of metal halide and high-pressure sodium lamps during photoperiod extension on the allocation of carbon between lignin and cellulose in black spruce seedlings

1988 ◽  
Vol 18 (7) ◽  
pp. 962-964 ◽  
Author(s):  
Hank A. Margolis ◽  
Jacques Bégin ◽  
Richard Beeson ◽  
Pierre Bellefleur
Keyword(s):  
High Pressure ◽  
Light Source ◽  
Black Spruce ◽  
Metal Halide ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Seedling Height ◽  
Active Radiation ◽  
Seedling Biomass

Containerized black spruce seedlings (Piceamariana (Mill.) B.S.P.) were grown at the greenhouse at CIP Inc., Harrington, Québec, from February until May, 1987. We wished to test whether differences in the quantity and quality of light received from two commercially available lamps during photoperiod extension would alter the allocation of carbon between lignin and cellulose in shoots and roots. Photoperiods were extended from 17:00 to 01:00 using either metal halide and high-pressure sodium lamps together or high-pressure sodium lamps alone. At night, the treatment using both types of lamp together increased the photon flux density of blue light (400–500 nm) at seedling height 10-fold, from 0.32 to 3.2 μE m−2 s−1. Photosynthetically active radiation was increased 4-fold, from 4.5 to 17.9 μE m−2 s−1. Total seedling biomass did not differ statistically between light treatments at any given time. However, seedling biomass averaged over all times was statistically higher (p ≤ 0.03) for seedlings in the treatment using both types of lamp together. Percent lignin, percent cellulose, and lignin to cellulose ratios were not significantly affected by the light source used during photoperiod extension. As expected, percent lignin and percent cellulose in shoots and roots increased significantly with time. The percentage of seedlings judged unacceptable because of spiralized stems was not affected by light source and averaged 21.9%.

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