Integration of microplasma sources in portable systems
sets constraints in the amount of power and vacuum levels
employed in these plasma sources. Moreover, in order to achieve
good power efficiency and prevent physical deterioration of the
source, it is desirable to keep the discharge temperature low. In
this paper, the thermal characteristics of an atmospheric argon discharge
generated with a low-power microwave plasma source are
investigated to determine its possible integration in portable systems.
The source is based on a microstrip split-ring resonator and
is similar to the one reported by Iza and Hopwood, 2003. Rotational,
vibrational, and excitation temperatures are measured by
means of optical emission spectroscopy. It is found that the discharge
at atmospheric pressure presents a rotational temperature
of ~300 K, while the excitation temperature is ~0.3 eV (~3500 K).
Therefore, the discharge is clearly not in thermal equilibrium. The
lowrotational temperature allows for efficient air-cooled operation
and makes this device suitable for portable applications including
those with tight thermal specifications such as treatment of biological
materials
