Measurement of metastable and resonance level densities in rare-gas plasmas by optical emission spectroscopy

作者：Boffard John B^*; Jung R O; Lin Chun C; Wendt A E

来源：Plasma Sources Science and Technology, 2009, 18(3): 035017.

DOI：10.1088/0963-0252/18/3/035017

Excitation and ionization of atoms out of the 4 energy levels of the excited np(5)(n + 1)s configuration of rare gases play an important role in many low temperature rare-gas plasmas. We compare two optical methods for measuring the number densities of atoms in these excited levels in an inductively coupled plasma under a variety of operating conditions (600 W, 1-25 mTorr). The first method is a standard white light absorption technique, whereas the second method exploits changes in the effective branching fractions of np(5)(n + 1) p -> np(5)(n + 1) s emissions brought about by radiation trapping of atoms in np(5)(n + 1) s levels. The branching fraction method was found to produce results that agree well with the direct white light absorption method for both argon and neon plasmas using little more than a low-resolution spectrum of the plasma glow.

• 出版日期2009-8