Mjerenje raspodjele elektronske energije u dvama područjima istosmjernog magnetrona za rasprašivanje

The electron energy distribution function (EEDF) at the edge of the cathode fall and positive column regions of Ar and He glow discharge were measured using a single Langmuir probe. The EEDF in the cathode fall region was found to be non-Maxwellian where two groups of electrons were detected. The two groups have no chance to be thermalized since they leave the cathode fall region fast. Sources of the two groups of electrons are discussed. Moreover, EEDF in the positive column region was found to be Maxwellian for both gases. Electrons have a chance to thermalize themselves due to the long plasma lifetime in this region.Primjenom Langmuirove sonde mjerili smo funkciju raspodjele elektronske energije (EEDF) na rubu katodnog tamnog prostora i u pozitivnom stupcu tinjavog izboja u Ar i He. U katodnom tamnom prostoru našli smo ne-Maxwellov EEDF s dvjema grupama elektrona. Ove dvije grupe ne mogu se termalizirati jer brzo napuštaju prostor tinjavog izboja. Raspravljamo uzroke dviju grupa. Međutim, u pozitivnom stupcu smo našli Maxwellovu EEDF. U tom je području trajanje plazme dugo i elektroni se mogu termalizirati

Površinska obrada polimera u tinjavom argonskom izboju

Surface treatment of polymer material (thin polyester samples) was performed in the DC glow discharge, using Ar gas. The effect of the experimental parameters of the glow discharge (the gas pressure and the sample treatment time) on the wettability of the samples was studied. The wettability was characterized by the water repellency (water spray test). In the present work, it was shown that at a constant gas pressure (270 or 670 Pa), the wettability of the polyester sample was decreased by increasing the exposure time of the sample in the glow discharge. At constant exposure times (2, 5, 10 or 15 min) the wettability of the polyester sample was increased by increasing the gas pressure. This is due to the formation of hydrophilic groups, which increased by increasing the density of electrons and/or metastables.Površinski smo obrađivali polimerni materijal (tanke uzorke poliestera) u istosmjernom tinjavom argonskom izboju. Proučavali smo učinke eksperimentalnih parametara izboja (tlaka plina i vremena izlaganja u izboju) na močivost uzoraka. Močivost smo određivali mjerenjem odbojnosti vode (metoda prskanjem vode). U ovom se radu pokazuje da se na stalnom tlaku plina (270 ili 670 Pa), močivost uzoraka poliestera smanjuje za dulja vremena izlaganja u izboju. Za određena vremena izlaganja (2, 5, 10 ili 15 min), močivost uzoraka je porasla pri povećanom tlaku argona. Razlog tome je stvaranje hidrofilnih grupa koje su bile brojnije pri povećanoj gustoći elektrona i/ili metastabila

Mjerenje probojnih napona za više katodnih materijala u Townsendovom izboju

The breakdown potentials have been measured for argon and helium discharges using three different cathode materials: aluminium, silver and magnesium. The measurements show that lower breakdown potentials are associated with lower work function of the cathode material. For the three different cathodes, the secondary ionization coefficients have been estimated using the measured values of the breakdown potentials and the first ionization coefficient, in the range 0.60 to 2.25 V/[Pa cm] (80 to 300 V/[torr cm]) for Ar discharge and in the range of 0.15 to 1.80 V/[Pa cm] (20 to 240 V/[torr cm]) for He discharge. The minimum breakdown potential has been found at (pd)min = 80 Pa cm (0.6 torr cm) in Ar discharge and at 530 Pa cm (4.0 torr cm) in He discharge.Mjerili smo probojne potencijale za izboj u argonu i heliju s trima katodnim materijalima: aluminijem, srebrom i magnezijem. Mjerenja pokazuju da su niži probojni naponi povezani s nižim radnim funkcijama. Odredili smo sekundarne ionizacijske koeficijente za te tri vrste katoda na osnovi izmjerenih probojnih napona i prvih ionizacijskih koeficijenata, u području 0.60 to 2.25 V/[Pa cm] za izboj u Ar i u području 0.15 to 1.80 V/[Pa cm] za izboj u He. Najniži probojni napon za izboj u Ar iznosi (pd)min = 80 Pa cm, a za izboj u He 530 Pa cm (4.0 torr cm)

Optimizations of ozone generator at low resonance frequency

The effect of the frequency on the different parameters of ozone generation in the dielectric barrier discharge (DBD) has been investigated. It is found that at low frequency, ($f_{0} = 325$ Hz), an electric resonance can be obtained in the electric circuit. The onset voltage, at which the ozone starts to build up, was reduced from 3.25 kV at 50 Hz to 1.57 kV at 325 Hz. The efficiency has been increased from nearly zero at 50 Hz to 232.94 g/kW h at 200 Hz under applied voltage of 2.025 kV

The influence of the addition of argon gas to air DB discharge

Effects of admixing argon to air DB discharge, at atmospheric pressure, on the electrical and optical emission characteristics have been studied. Optical emission spectroscopy is used to investigate the effect of argon admixing on the emission intensity of the nitrogen second positive systems (300–450 nm) and its relative population of N2(C3Πu,v′) state. Also the vibrational temperature of the nitrogen second positive systems has been calculated for the sequence Δv = −2, that follows Boltzmann’s distribution. It was found that the vibrational temperature of second positive system can be raised significantly from 0.31 to 0.35 eV in air dielectric barrier discharge (DBD) plasma at discharge current 0.5 mA with admixing of Ar gas at flow rate of 3 L/min. Admixing of argon to air DB discharge also enhances the discharge current, the electron density and the consumed power. Mechanisms of excitation and ionization processes of nitrogen molecules in this mixture have been studied. Processes which are responsible for the enhancement of the population density of N2(C3Πu,v′) and its vibrational temperature have been reported