ISSN:
1432-0630
Keywords:
52
;
32
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract The spatial and temporal development of the temperature and the electron density of a spark produced in He at 10 atm in the focus of a lens by a mode-locked laser pulse having only 1.5 mJ energy have been investigated. Measuring the absolute intensity of the continuum radiation emitted by the spark and the broadening of a Heii-line it can be concluded that local thermodynamic equilibrium has established 15 ns after the initiation of the plasma. At this time a temperature of 65000 K and a maximum electron density of 1.4·1019 cm−3 was found with a pressure of 20 times the initial gas pressure. These values are in agreement with the values required for an expansion model given in an earlier work basing on a radiation mechanism which explains the stepwise growth of a laser spark under the influence of a train of mode-locked pulses.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00882470
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