Edge radiation spectra of luminescent ceramic A2B6

1986 ◽  
Vol 45 (3) ◽  
pp. 953-957
Author(s):  
A. I. Proskura ◽  
I. V. Zakharchenko
Keyword(s):  
Radiation Spectra ◽  
Edge Radiation

Influence Of Ti Related Centers On ZnSe Radiation Spectra

1997 ◽  
Vol 487 ◽  
Author(s):  
L.I. Bruk ◽  
V. A. Korotkov ◽  
P. I. Ketrush ◽  
A. V. Simashkevich ◽  
K. D. Sushkevich ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Homogeneous Field ◽  
Volume Distribution ◽  
Acceptor Center ◽  
Radiation Spectra ◽  
Edge Radiation ◽  
Blue Radiation ◽  
Exciton Region ◽  
Ti Addition ◽  
Good Agreement

AbstractZnSe annealed in (Zn + 46 wt.% TI) vapors and in Zn melt with 5 wt.% TI addition was investigated. The radiation spectra in the regimes of stationary and pulsed photoluminescence (PL) with the time delaying at 77K were studied. By using coloured cathodoluminescence (CCL) combined with the crystal cleavage image in the secondary electrons reflection the impurities and defects volume distribution was evaluated. It was revealed that at the annealing of ZnSe crystals in TI vapors, the cleavage surface has light blue radiation on the red background with an homogeneous field distribution with the dimensions ˜ 1..10μm. On the edge of the cleavage on the depth of 10μm the region of yellow radiation is observed. At the annealing in the melt the irradiation became blue on a weak red background, the homogeneity enhances. At the room temperature PL spectra correspond with images of cleavage in CCL. In the PL (at 77K) spectra in the exciton region there were observed: bands at 445nm (blue radiation); edge radiation at 460nm, 485nm with the LO phonons replica (blue region) and in the impurity region: bands 500...570nm (yellow-green radiation); 600...700nm and 720...800nm (red radiation). The investigation of PL of the annealed samples surface allowed the suppose, that the bands at 2,76eV (450nm), are stipulated by the free-bound transition on the acceptor center (E + 40meV), including TI.The comparison of ion and tetrahedronical covalent radiuses of Zn, Se and TI, electronegativity, probability of Zni and Vse. formation at the annealing allowed to suppose that, TI fills Vse. and forms (Zni Tls) and (Vse. Tlse) complexes. The carried out theoretical calculations according to the model of two-atom molecule gives the energy of complexes occurrence (Ev + 0,04) eV and (Ev + 0,8) eV. The first value accordingly is in good agreement with the experimental data.

The Influence Of The Led Luminaires Electrical Parameters On Their Correlated Colour Temperature During Operation Mode

2020 ◽  
pp. 89-96
Author(s):  
Sergei S. Kapitonov ◽  
Alexei S. Vinokurov ◽  
Sergei V. Prytkov ◽  
Sergei Yu. Grigorovich ◽  
Anastasia V. Kapitonova ◽  
...  
Keyword(s):  
Operation Mode ◽  
Light Sources ◽  
Electrical Parameters ◽  
Colour Temperature ◽  
Radiation Spectra ◽  
Service Period ◽  
Close Proximity ◽  
Definition Of ◽  
Comprehensive Study

The article describes the results of comprehensive study aiming at increase of quality of LED luminaires and definition of the nature of changes in their correlated colour temperature (CCT) in the course of operation. Dependences of CCT of LED luminaires with remote and close location of phosphor for 10 thousand hours of operation in different electric modes were obtained; the results of comparison between the initial and final radiation spectra of the luminaires are presented; using mathematical statistics methods, variation of luminaire CCT over the service period claimed by the manufacturer is forecast; the least favourable electric operation modes with the highest CCT variation observed are defined. The obtained results have confirmed availability of the problem of variation of CCT of LED luminaires during their operation. Possible way of its resolution is application of more qualitative and therefore expensive LEDs with close proximity of phosphor or LEDs with remote phosphor. The article may be interesting both for manufacturers and consumers of LED light sources and lighting devices using them.

Radiation spectra of electric discharge in adenine vapors

2015 ◽  
Vol 38 (0) ◽  
pp. 33-37
Author(s):  
Юрій Юрійович Свида ◽  
Марія Іллівна Суховія ◽  
Микола Олексійович Маргітич ◽  
Мирослав Іванович Шафраньош ◽  
Іван Іванович Шафраньош
Keyword(s):  
Electric Discharge ◽  
Radiation Spectra

On the Nature of the Near-Edge Radiation of ZnO at Room Temperature

2020 ◽  
Vol 62 (11) ◽  
pp. 2138-2142
Author(s):  
I. Kh. Akopyan ◽  
M. E. Labzovskaya ◽  
B. V. Novikov ◽  
A. Yu. Serov ◽  
N. G. Filosofov ◽  
...  
Keyword(s):  
Room Temperature ◽  
Edge Radiation

scholarly journals Testing the potential of LEDs to enhance growth and quality characteristics of Salvia fruticosa

2019 ◽  
Vol 46 (No. 2) ◽  
pp. 98-106 ◽  
Author(s):  
Filippos Bantis ◽  
Kalliopi Radoglou
Keyword(s):  
Root Biomass ◽  
Weight Ratio ◽  
Dry Weight ◽  
Total Phenolic ◽  
Root Weight ◽  
Light Emitting ◽  
Shoot Dry Weight ◽  
Radiation Spectra ◽  
Salvia Fruticosa ◽  
Developmental Characteristics

The effect of light-emitting diodes (LED) with broad radiation spectra on developmental, physiological, and phytochemical characteristics of Greek sage (Salvia fruticosa L.) seedlings was assessed. Fluorescent (FL – control) tubes and four LED lights [AP67 (moderate blue, red and far-red), L20AP67 (moderate blue, red and far-red, high green), AP673L (moderate blue, high red) and NS1 (high blue and green, low red, high red : far-red, 1% ultraviolet)] were used in a growth chamber. Seedlings grown under FL, L20AP67 and AP673L exhibited the best morphological and developmental characteristics. FL led to inferior root biomass formation compared to all LEDs. AP67 promoted greater root-to-shoot dry weight ratio and dry-to-fresh overground and root weight ratios, but induced the least morphological and developmental characteristics. NS1 performed well regarding the root biomass production. Total phenolic content and the root growth capacity were not significantly affected. The present study demonstrates that L20AP67 and AP673L LEDs performed equally to FL light regarding the developmental characteristics. AP67 and NS1 may have the potential to be used for compact seedling production.

Review and present status of the TEXTOR radiative improved (RI) mode

1998 ◽  
Vol 59 (4) ◽  
pp. 587-610 ◽  
Author(s):  
P. E. VANDENPLAS ◽  
A. M. MESSIAEN ◽  
J. P. H. E. ONGENA ◽  
U. SAMM ◽  
B. UNTERBERG
Keyword(s):  
Density Profile ◽  
High Power ◽  
Present Status ◽  
Particle Transport ◽  
Density Limit ◽  
Radiated Power ◽  
Edge Radiation ◽  
Intermediate Size ◽  
Power Fraction ◽  
Better Than

From 1990, the boronized TEXTOR tokamak was characterized by an improved confinement (coined the ‘I mode’) at high power that was substantially better than the L mode, but densities had to be limited to n[bar]e0/nGR[lsim ]0.5–0.6, where nGR is the Greenwald density limit. With the injection of Ne, Si or Ar in order to increase the edge radiation and provided that γ=Prad/Ptot[greater, similar]0.5, PNBI-co/Ptot[greater, similar]0.25 and n[bar]e0/nGR[greater, similar]0.75, a further improved confinement called the radiative improved mode (RI mode) was discovered in 1993 on TEXTOR, a tokamak of intermediate size, and confirmed on TEXTOR-94. The radiated power fraction γ can reach 0.9, and the radiation is nearly isotropically distributed over the torus wall. The RI mode is characterized by its ability to obtain simultaneously and stationarily high densities and high confinement. It is linked to a substantial lowering of edge ne, Te and Ti, a reduction in particle transport and a peaking of the density profile. The RI-mode confinement scales on TEXTOR as τE= (n[bar]e0/nGR)τITERH93-P and values up to n[bar]e0/nGR≈1.2 are obtained. There is no detrimental concentration of the seeded impurity at the centre of the plasma. Results of three different interpretative and modelling approaches are in agreement with the improved confinement features; the preliminary indications are that ITG turbulence is strongly reduced. The Z mode observed on ISX-B has a clear resemblance to the RI mode. The very favourable features of the RI mode justify efforts in trying to establish it on larger machines to verify if the present scaling then holds.

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