Plasma formation

Lasers act as sources and sometimes as amplifiers of coherent k—uv radiation. Excitation in lasers is provided by external particle or photon pump sources. The high energy densities requked to create inverted populations often involve plasma formation. Certain plasmas, eg, cadmium, are produced by small electric discharges, which act as laser sources and amplifiers (77). Efforts that were dkected to the improvement of the energy conversion efficiencies at longer wavelengths and the demonstration of an x-ray laser in plasma media were successful (78). 

The last problem of this series concerns femtosecond laser ablation from gold nanoparticles [87]. In this process, solid material transforms into a volatile phase initiated by rapid deposition of energy. This ablation is nonthermal in nature. Material ejection is induced by the enhancement of the electric field close to the curved nanoparticle surface. This ablation is achievable for laser excitation powers far below the onset of general catastrophic material deterioration, such as plasma formation or laser-induced explosive boiling. Anisotropy in the ablation pattern was observed. It coincides with a reduction of the surface barrier from water vaporization and particle melting. This effect limits any high-power manipulation of nanostructured surfaces such as surface-enhanced Raman measurements or plasmonics with femtosecond pulses. 

An important point is that these advances have been complemented by the concomitant development of innovative pulse-characterisation procedures such that all the features of femtosecond optical pulses - their energy, shape, duration and phase - can be subject to quantitative in situ scrutiny during the course of experiments. Taken together, these resources enable femtosecond lasers to be applied to a whole range of ultrafast processes, from the various stages of plasma formation and nuclear fusion, through molecular fragmentation and collision processes to the crucial, individual events of photosynthesis. 

Flannigan DJ, Suslick KS (2005) Plasma formation and temperature measurement during single-bubble cavitation. Nature (London) 434 52-55... 

Matsui, T. and H. Satz. J/T suppression by quark-gluon plasma formation. Physics Letters B, 178 416, 1986. 

Mcrowave -molybdenum-rhenium alloys for [MOLYBDENUM AND MOLYBDENUM ALLOYS] (Vol 16) -for plasma formation [PLASMA TECHNOLOGY] (Vol 19)... 

Fukuda Y, Yamakawa K, Akahane Y, Aoyama M, Inoue N, Ueda H, Abdallah Jr. J, Csanak G, Faenov AYa, Magunov AI, Pikuz TA, Skobelev IYu, Boldarev AS, Gasilov VA (2003a) X-ray study of microdrop let plasma formation under the action of superintense laser radiation. JETP Lett. 78 115-118... 

Plasma formation and the characteristics of glow discharge processes are subjects of extensive monographs [27,28],... 

Plasma Formation in Alkali Metal Vapors by Quasi-Resonant Laser Excitation... 

The first condition of plasma formation due to quasi-resonant laser excitation is that collisional ionization (4) or (5) be sufficiently fast (compared to radiative decay rate of A ),... 

QRLPP is a general plasma-formation mechanism, already demonstrated for Cs, Rb, Na, and Li vapors. It should also be useful for other vapors or vapor mixtures, e.g., alkaline earth metal vapors. 

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