21 KB1995 KB19 KB198120221998Bizjak, MartinKoller, LidijaMozetič, MiranPožun, Karolletnik:18številka:44 stranistr. 4-7ISSN:0351-9716COBISSID:32482URN:URN:NBN:SI:doc-NROPAI1HslDruštvo za vakuumsko tehniko SlovenijeVakuumistfizika vakuumakatalizakisikplazmaravnotežjevpliv temperatureMetoda za oceno stopnje neravnovesnosti kisika pri nizkem tlaku|A simple tool for estimation of the degree of nonequilibrity of oxygen is described. Thermodynamic nonequilibrum state of the gas is obtained by drifting the gas through a weakly ionized oxygen plasma, which is created in a glass vacuum chamber by an inductively coupled rf generator. A nickel catalytic probe is immersed in gas and its first time derivative after turning on on the RF generator is measured. Assuming the probe is heated mainly due to recombination of neutral atomsoxygen atoms on its surface, the degree of nonequilibrity is calculated. The temperature, corresponding to the concentration of excited particles in thermodynamic equilibrum , is calculated as well. The degree of nonequilibrity of gas is estimated at different pressures between 4 and 200 Pa, and the corresponding equilibrum temperature is of the order of 10000 KOpisujemo preprosto napravo za oceno stopnje neravnovesnosti kisika. Termodinamsko neravnovesno stanje plina dosežemo pri prehodi le-tega skozi šibko ionizirano kisikovo plazmo, ki jo ustvarimo v stekleni vakuumski komori z induktivno vezanim RF generatorjem. V plin namestimo nikljevo katalitično sondo in merimo časovni odvod temperature sonde po vklopu generatorja. Ob predpostavki, da se sonda ogreva predvsem zaradi rekombinacije nevtralnih kisikovih atomov na njeni površini, izračunamo stopnjo neravnovesnosti plina in temperaturo, ki bi jo imel plin s tolikšno koncentracijo vzbujenih delcev v ravnovesnem stanju. Stopnjo neravnovesnosti smo ocenili pri različnih tlakih med 4 in 200 Pa in ugotovili, da je ustrezna ravnovesna temperatura plina reda 10000 KTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaDruštvo za vakuumsko tehniko Slovenije