Helium (He) inductively coupled plasma (ICP) was generated by a right-helical-type RF antenna. At a fixed He pressure of 20 mTorr, the optical emission spectrum from the He plasma was measured with RF power. The E-H mode transition and the characteristic hysteresis of the mode transition were confirmed by a change in the spectral line intensity of the ${\mathrm{3}}^{3}D-2^{3}P$ transition at 587.6 nm. By laser absorption spectroscopy using a laser light with a wavelength of 1083 nm resonant to the ${\mathrm{2}}^{3}S\to 2^{3}P$ absorption transition, the line-integrated He ${\mathrm{2}}^{3}S$ metastable density was measured and found to show consistent behavior with the spectral line intensity of the ${\mathrm{3}}^{3}D-2^{3}P$ transition during the E-H mode transition. The line-integrated He ${\mathrm{2}}^{3}S$ metastable atom density exhibited distinctly different longitudinal distributions in the E and H modes.

氦（He）感应耦合等离子体（ICP）是由右螺旋型RF天线产生的。在20 mTorr的固定He压力下，用RF功率测量He等离子体的发射光谱。EH模式转换和模式转换的特征磁滞通过改变光谱线强度来确定。${\mathrm{3}}^{3}d-{\mathrm{2个}}^{3}P$在587.6 nm处跃迁 通过激光吸收光谱法，使用与激光共振的波长为1083 nm的激光${\mathrm{2个}}^3\mathrm{小号}\to {\mathrm{2个}}^{3}P$ 吸收跃迁，线积分氦 ${\mathrm{2个}}^3\mathrm{小号}$ 测量了亚稳密度，发现与亚稳谱线强度一致。 ${\mathrm{3}}^{3}d-{\mathrm{2个}}^{3}P$在EH模式转换期间转换。行整合式${\mathrm{2个}}^3\mathrm{小号}$ 亚稳原子密度在E和H模式下表现出明显不同的纵向分布。