Question

Asked 23 July 2018

Quaid-i-Azam University

Why Argon gas is used in LIBS experiment.?

Why Argon gas is being used in LIBS experiment.?

I have read a paper

" (LIBS) of Heavy Metal Ions at the Sub-Parts per Million Level in Water "

in which they have used flowing argon gas while performing experiment.. why .?

LIBS

Argon

Sagheer Mehmood

Quaid-i-Azam University

Thanku Sir Muhammad Aslam Baig and All Others

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Virendra Nath Rai

Raja Ramanna Centre for Advanced Technology

Dear Sagheer

Please read carefuly that paper. If they have used argon gas in the experiment. They must have explained the reason for using that gas. However in general argon gas is used in LIBS experiment to enhance the signal (sensitivity) of the LIBS. The shock wave generated at the boundary of plasma and argon gas compresses the plasma, which increases the plasma temperature and density resulting in comparatively higher LIBS signal.

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Virendra Nath Rai

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Dear Sagheer

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Argon is used basically to increase signal.The cause of the overall signal enhancement is due to the confinement of the laser-induced plasma in the presence of argon. Due to the heavier density and lower thermal conductivity of argon relative to air, the overall plasma is confined near the sample surface in argon relative to air. The confined plasma increases the number of collisions that might be responsible for more excitation of species in the laser-induced plasma and leads to the enhancement of the overall LIBS signal in an argon atmosphere.

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Sagheer Mehmood

Quaid-i-Azam University

Thanku Sir Muhammad Aslam Baig and All Others

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