Naslov
Gas or plasma jet: Targets for Laser Induced Breakdown Spectroscopy

Autori
Popović, Dean ; Bišćan, Marijan ; Šegedin, Nikola ; Milošević, Slobodan

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
7th Central European Symposium on Plasma Chemistry, Scientific Program and Book of Abstracts / Milošević, Slobodan ; Krstulović, Nikša - Zagreb : Institut za fiziku, 2017, 118-118

ISBN
978-953-7666-16-3

Skup
7th Central European Symposium on Plasma Chemistry, CESPC-7

Mjesto i datum
Sveti Martin na Muri, Hrvatska, 03.09.2017. - 07.09.2017

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Laser induced breakdown, atmospheric pressure plasma jet, time-resolved optical emission spectroscopy

Sažetak
In our work, we have investigated the difference between using a gas target or a plasma jet as a target for Laser Induced Breakdown Spectroscopy. Laser plasma was produced by focusing the Nd:YaG laser pulse (4-5 ns pulse duration) either into the gas target or plasma jet. The plasma jet was generated by using either sinusoidal-like or pulsed-DC high voltage with frequency around 25 or 10 kHz respectively. Shielding gas was implemented in the experimental setup to reduce the interaction between helium metastables and nitrogen molecules and enable diagnostics. Since both types of plasma evolve in time very fast, time-resolved spectroscopy was used as a main diagnostical method. For this purpose light that the plasmas emit was collected with optical fibre from focal region to monochromator. After passing the monochromator’s exit slit, the light was detected with photomultiplier tube and the signal recorded on the computer. From the measured spectral line profiles we determined the electron temperatures and concentrations for different time windows. Interesting observation was the decrease in He (388.86 nm) emission line intensity when the laser was focused into the plasma jet, compared to the case where only the gas target was used. This is because of the reabsorption of the emitted light on the efficiently produced helium metastables in the plasma jet.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA