AVS 58th Annual International Symposium and Exhibition
    Advanced Surface Engineering Division Wednesday Sessions
       Session SE+PS-WeA

Paper SE+PS-WeA9
High Performance of 60-Hz Atmospheric Pressure Plasma: Basic Characteristics and Applications

Wednesday, November 2, 2011, 4:40 pm, Room 104

Session: Atmospheric Pressure Plasmas
Presenter: Fengdong Jia, Nagoya University, Japan
Authors: F. Jia, Nagoya University, Japan
K. Takeda, Nagoya University, Japan
K. Ishikawa, Nagoya University, Japan
H. Inui, Nagoya University, Japan
S. Iseki, Nagoya University, Japan
H. Kano, NU Eco-Engineering Co., Ltd., Japan
H. Kondo, Nagoya University, Japan
M. Sekine, Nagoya University, Japan
M. Hori, Nagoya University, Japan
Correspondent: Click to Email
In this paper, the spatial distribution of atomic oxygen density in a 60-Hz non-equilibrium atmospheric pressure plasma[1] is diagnosed by two-photon absorption laser induced fluorescence (TALIF)[2] . The plasma unit is made of ceramics comprised three regions: gas diffusion region, main discharge region, and plasma jet in the open air. The discharge gases were Ar and a small amount of O2. The plasma could offer electron density as high as 1015 cm-3 with a low gas temperature[1,3], and have been successfully used to clean glass surface[1]and inactivate the spores of Penicillium digitatum[4]. In the above applications, we find that atomic oxygen plays an important role[1,4], and the samples are usually treated in the open air; therefore it is necessary to investigate the behavior of atomic oxygen, especially in the open air, in order to achieve high performance. A dye laser pumped by an excimer laser is used to generate nanosecond UV laser pulses at around λ= 226 nm for the two-photon excitation of atomic oxygen (2p 3P−3p 3P). The laser power is adjusted to 0.1 mJ/pulse to make sure that the effect of photo dissociation of ozone can be negligible in the experiment. The results showed that the effect of O2 admixture variation on the atomic oxygen density is totally different in the main discharge region and in the plasma jet. In the main discharge region where the discharge gas are only Ar and O2, the density of atomic oxygen increased quickly with adding only 0.25% O2, became saturated with adding 1% O2, and reduced quickly when adding 1.5% O2. The discharge was stable until adding 2.5% O2. However, in the plasma jet that was in the open air, the density of atomic oxygen remained almost same while adding O2 from 0% to 2.5%. This is because the mechanisms of generation and recombination of atomic oxygen are different in the main discharge region and plasma jet. More work will be done to study the behavior of atomic oxygen in the plasma jet, the data and results will be very useful to understand the behavior of atomic oxygen and improve the applications of non-equilibrium atmospheric pressure plasma. [1] M. Iwasaki, H. Inui, Y. Matsudaira, H. Kano, N. Yoshida, M. Ito, and M. Hori, Appl. Phys. Lett. 92, 081503 (2008). [2] K. Niemi, V. Schulz-von der Gathen, and H. F. Dobele, Plasma Sources Sci. Technol. 14, 375 (2005). [3] Fengdong Jia, Naoya Sumi, Kenji Ishikawa, Hiroyuki Kano, Hirotoshi Inui, Jagath Kularatne, Keigo Takeda, Hiroki Kondo, Makoto Sekine, Akihiro Kono, and Masaru Hori, Appl. Phys. Express, 4, 026101 (2011). [4] S. Iseki, T. Ohta, A. Aomatsu, M. Ito, H. Kano, Y. Higashijima, and M. Hori, Appl. Phys. Lett. 96, 153704 (2010).