Emission cross sections for H, C and He produced in He++ CH4 collisions

Emission cross sections for hydrogen Lyman-α, -β, Balmer-α, -β, C(3s 3PJ'o→2p2 3PJ, 165.7 nm), C(2p3 3DJ'o→2p2 3PJ, 156.1 nm) and He(2p 1P1→1s2 1S0, 58.4 nm) produced in He+ + CH4 collisions are measured in the energy range from 4 eV (cm) to 4000 eV (cm). The emission cross sections of hydrogen Lyman and Balmer series have a plateau above 100 eV. The cross sections of helium and carbon lines decrease rapidly with decreasing collision energy. The branching ratio when an excited hydrogen with n = 2 is produced is estimated to be 2.5×10-2 at 4000 eV by using measured emission cross sections for Hα to He and by empirical relations.

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