Intense Laser-Matter Interactions. An Approach to Laser Driven Electronic and Nuclear Energy Transfer

1988 ◽  
Author(s):  
Francis X. Hartmann ◽  
Karen K. Garcia ◽  
Donald W. Noid ◽  
Michael L. Koszykowski ◽  
John K. Munro ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Nuclear Energy ◽  
Intense Laser

Photoluminescence of Eu3+ in Si/SiO2 Nanostructure Films

2000 ◽  
Vol 609 ◽  
Author(s):  
Huimin Liu ◽  
Aziz Mahfoud ◽  
G. A. Nery ◽  
O. Resto ◽  
Luis F. Fonseca ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Life Time ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Intense Laser ◽  
Time Resolved ◽  
Silicon Matrix ◽  
Sputtering Deposition ◽  
Direct Excitation

ABSTRACTEu3+ -doped Si/SiO2 nanocomposites were successfully prepared by Ar sputtering deposition on quartz substrates. The optical properties were studied using time-resolved photoluminescence spectroscopy. Excited by intense picosecond laser pulses with energy greater than1GW/cm2 and wavelength at 532nm the observed photoluminescence consists of a rapidly decaying component with life time of ∼1 s and a slowly component with life time of ∼ 2 ms. The former was recognized as coming from Si/SiO2 nanostructures matrix while the latter as coming from the impurity Eu3+ ions. Using the intense laser excitation a two-photon absorption by silicon matrix occurred, resulting in photo-induced carriers produced in conduction band. A direct recombination from Si/SiO2 nanostructure host gives a weak but fast emission, and creates a large number of nonequilibrium phonon. For Eu3+ emission a set of 5D0 to 7F multiplet transitions were identified. In addition to the direct excitation by 532nm the excited state 5D0 of Eu3+ ions was also found to be populated due to energy transfer from silicon matrix. The mechanism of phonon-assisted energy transfer is discussed.

scholarly journals Crossed beam energy transfer between optically smoothed laser beams in inhomogeneous plasmas

2020 ◽  
Vol 378 (2184) ◽  
pp. 20200038
Author(s):  
Stefan Hüller ◽  
Gaurav Raj ◽  
Mufei Luo ◽  
Wojciech Rozmus ◽  
Denis Pesme
Keyword(s):  
Energy Transfer ◽  
Inertial Confinement Fusion ◽  
Beam Energy ◽  
Random Phase ◽  
Intense Laser ◽  
Laser Beams ◽  
Band Width ◽  
Flow Profile ◽  
Smoothing Techniques ◽  
Spatio Temporal

Crossed beam energy transfer, CBET, in high-intensity laser–plasma interaction is investigated for the case of optically smoothed laser beams. In the two approaches to laser-driven inertial confinement fusion experiments, the direct-drive and the indirect-drive, CBET is of great importance because it governs the coupling of laser energy to the plasma. We use the two-dimensional wave-coupling code H armony to simulate the transfer between two laser beams with speckle structure that overlap in a plasma with an inhomogeneous flow profile. We compare the CBET dynamics for laser beams with spatial incoherence and with spatio-temporal incoherence; in particular we apply the smoothing techniques using random phase plates (RPPs) and smoothing by spectral dispersion (SSD), respectively. It is found that for laser beams (wavelength λ 0 ) with intensities ( I L ) above I L  ∼ 2 × 10 15  W cm −2 ( λ 0 /0.35 µm) −2 ( T e /keV), both the so-called plasma-induced smoothing as well as self-focusing in intense laser speckles induce temporal incoherence; the latter affects the CBET and the angular distribution of the light transmitted behind the zone of beam overlap. For RPP-smoothed incident beams, the resulting band width of the transmitted light can already be of the same order as the effective band width of the SSD available at major laser facilities. We examine the conditions when spatio-temporal smoothing techniques become efficient for CBET. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.

Ionization and Energy Transfer in Polyatomic Molecules under Ultrafast Intense Laser Field

2010 ◽  
Vol 47 (9) ◽  
pp. 093203
Author(s):  
胡湛 Hu Zhan ◽  
金明星 Jin Mingxing ◽  
吴迪 Wu Di ◽  
石英 Shi Ying ◽  
王巧巧 Wang Qiaoqiao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Laser Field ◽  
Polyatomic Molecules ◽  
Intense Laser ◽  
Intense Laser Field

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

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