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Density power in a focus reaches value of about 30
GW/cm . After plasma formation, the temperature and electron density
19 -3 is 25 000 K and 10 cm , respectively. The analyser employed
specially designed air cooled Nd:YAP laser emitting at the
wavelength of 1.079 mm, energy 0.1 J, and pulse duration of 10 ns.
All parameters of laser system were controlled by
computer. Optical system of the analyser consists of a microscope
for sample examination and selection of some part of its
surface for analysis, objective focusing a beam at the chosen part
of a sample, collimator collecting plasma radiation and
directing a beam at a photodetector's receiving surface. Interaction
of each pulse of laser radiation with the sample causes
evaporation of about 100 ng of it and a cavity of the diameter
smaller than 100 µm and depth of about 12 µm occurs at the
sample surface. Thus, such small cavity dimensions proved that the
checking method is of non-destructive nature. The
sample is situated on a testing table, controlled by PC computer.
The table's shifts in the X, Y, and Z directions are made by
means of three-step motors. Many well-known elements have radiation
lines within UV wavelengths, from 220 to 420 nm
so, the spectrometer has diffraction grating of a holographic type
and CCD matrix. It ensures the spectrometer sensitivity
-5 -4 of 10 ÷10 (the smallest detected value), in dependence on
element type and the spectrometer resolution of about 1.5 nm.
Finally, there is possible fast analysis of chemical constitution of
materials determining elements from N3 to N92 of the
periodic table. The result of a qualitative analysis is displayed on
a screen in form of a spectrum with basic chemical
elements denoted over adequate spectral lines and also in a table
with elements detected in the sample.
APPLICATION
Analysis of biological samples
Analysis of geologic samples
Testing of glasses and ceramics
Qualitative inspection on production lines
Analysis of chemical composition of metals and alloys
Semiconductor industry - analysis of superficial dirts
Fast analysis of degree of ground pollutions and building materials
Medical diagnosis of different diseases by fast analysis of chemical
composition of human cells
Qualitative and quantitative analysis of chemical composition of
various materials; solids and liquids
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