A theoretical insight into low-temperature atmospheric-pressure He+H2 plasmas

摘要: H2-containing low-temperature plasmas are used in a wide range of industrial applications. In recent decades, efforts have been made to understand and improve the performance these plasmas, mainly when operated at low medium pressures. Studies hydrogen-containing atmospheric pressure, however, scarce despite potential advantage operation vacuum-free environment. Here chemistry atmospheric-pressure He + H2 is studied by means global model that incorporates 20 species 168 reactions. It found for fixed average input power plasma density decreases sharply H2 concentration higher than ∼0.2%, whereas atomic H peaks ∼2%. Operation larger concentrations leads lower densities because high significant dissipated via vibrational excitation there an increasing presence negative ions (H−). Key chemical processes identified reduced sets reactions capture main physicochemical discharge proposed use computationally demanding models. The actual waveform affect electrons, metastables but it has little influence on requiring energy their formation, such as hydrogen states hydrogen.