Autor: Hahn, B. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Absorption and Photoluminescence of ZnSe/Zn$\text{}_{x}$Cd$\text{}_{1-x}$Se Superlattices and Quantum Wells under Hydrostatic Pressure
Autorzy:: Griebl, E.
Kerner, W.
Haserer, B.
Reisinger, T.
Hahn, B.
Gebhardt, W.
Tematy:: 62.50.+p
68.65.+g
42.50.-p; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1952528.pdf Link otwiera się w nowym oknie
Opis:: We present absorption measurements of a pseudomorphic Zn$\text{}_{0.75}$Cd$\text{}_{0.25}$Se/ZnSe superlattice and a Zn$\text{}_{0.91}$Cd$\text{}_{0.09}$ Se/ZnSe single quantum well under high hydrostatic pressure applied by a diamond anvil cell. Excitonic transitions as 1s-heavy hole and 1s-light hole between the first bound states or minibands as well as transitions in the buffer material are visible. Transition energies are well understood by calculations of the band structure near Γ. The observed energy distance between photoluminescence and hh-absorption signal gives information on exciton localization. Whereas this distance is nearly pressure independent in the buffer, there is a significant increase at pressures P > 5 GPa for quantum structures.
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Absorption of Thin ZnSe, ZnS and ZnS$\text{}_{x}$Se$\text{}_{1-x}$ Films under High Hydrostatic Pressure
Autorzy:: Griebl, E.
Schőtz, G.
Birzer, Ch.
Kerner, W.
Reisinger, T.
Hahn, B.
Gebhardt, W.
Tematy:: 73.61.Ga
71.35.+z; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1934060.pdf Link otwiera się w nowym oknie
Opis:: We present absorption measurements on free-standing ZnSe, ZnS and ZnS$\text{}_{x}$Se$\text{}_{1-x}$ films (d = 0.4...2 μm) under hydrostatic pressure up to 15 GPa. The refraction index n(λ,P) of ZnS and ZnSe in the transparent region up to 800 nm and the pressure shift of the E0 absorption edge of ZnSe and some ZnS$\text{}_{x}$Se$\text{}_{1-x}$-compositions was investigated at 293 K. At 2 K free exciton states near the E$\text{}_{0-}$ and E$\text{}_{0}$ + Δ$\text{}_{0}$-gap are visible in absorption. Increase in the Rydberg energy under pressure was found, which is explained with k • p-theory in the framework of the hydrogen model.
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Advances in High Intensity e-Beam Diode Development for Flash X-Ray Radiography
Autorzy:: Oliver, B.
Hahn, K.
Johnston, M.
Portillo, S.
Tematy:: 41.75.Fr
41.75.Ht
41.50.+h
52.59.Mv
87.59.B-; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1807904.pdf Link otwiera się w nowym oknie
Opis:: Recent experiments at Sandia National Laboratories have demonstrated an electron beam diode X-ray source capable of producing >350 rad at one meter with 1.7 mm FWHM X-ray source distribution, with a 50 ns pulse-width and X-ray photon endpoint energy spectrum in the 6-7 MeV range. The diode operates at current densities of ≈1 MA/$cm^{2}$. The intense electron beam rapidly ( ≈ 5 ns) heats the X-ray conversion anode/target, liberating material in the form of low density ion emission early in the pulse and high density plasma later. This environment gives rise to beam/plasma collective effects which dominate the diode and beam characteristics, affecting the radiation properties (dose and spot-size). A review of the diode operation, the measured source characteristics and the simulation methods and diagnostics used to guide its optimization is given.
Dostawca treści:: Biblioteka Nauki