[1] [1] Cummins T, Otsuka T, Yugami N, et al. Applied Physics Letter, 2012, 100(6): 061118.

[2] [2] Otsuka T, Kilbane D, White J, et al. Applied Physics Letter, 2010, 97(11): 111503.

[3] [3] Bakshi V. EUV Source for Lithography. SPIE, 2006. 634.

[4] [4] Morris O, Hayden P, O’Reilly F, et al. Applied Physics Letter, 2007, 91(8): 081506.

[5] [5] Sakaguchi H, Fujioka S, Namba S, et al. Applied Physics Letter, 2008, 92(11): 111503.

[6] [6] Namba S, Fujioka S, Sakaguchi H, et al. Journal of Applied Physics, 2008, 104(1): 013305.

[7] [7] Harilal S S, O’Shay B, Tillack M S. Journal of Applied Physics, 2005, 98(1): 013306.

[8] [8] Masnavi M, Szilagyi J, Parchamy H, et al. Applied Physics Letter, 2013, 102(16): 164102.

[9] [9] Suzuki C, Koike F, Murakami I, et al. Physica Scripta, 2013, T156: 014078.

[10] [10] Sakaguchi H, Fujioka S, Namba S, et al. Space, 2006.

[11] [11] Claeyssens F, Cheesman A, Henley S J, et al. Journal of Applied Physics, 2002, 92(11): 6886.

[12] [12] O’Sullivan G. Journal of Physics B: Atomic and Molecular Physics, 1983, 16: 3291.

[13] [13] Higashiguchi T, Otsuka T, Yugami N, et al. Applied Physics Letter, 2011, 99(19): 191502.

[14] [14] Aragón C, Aguilera J A. Spectrochimica Acta Part B, 2008, 63: 893.

[15] [15] Griem H R. Plasma Spectroscopy. New York: McGraw-Hill Book Company, 1964. 519.