Electron-Impact Excitation Cross-Sections for Helium-like Ions: C V, N VI, O VII and Ne IX

By use of the non-relativistic Coulomb-Born approximation, calculations have been performed for cross sections of electron-impact excitation in helium-like ions (C, V, N, VI, O VII and Ne IX) in the cases of 1 1 S→ n 1 P ( n =2, 3), 2 3 S→ n 3 P ( n =2, 3) and 2 3 P→3^3 S t r a n s i t i o n s . I n v i e w o f t h e a p p l i c a t i o n t o h i g h - t e m p e r a t u r e p l a s m a s t h e c r o s s s e c t i o n s f o r r e s p e c t i v e i o n s h a v e b e e n o b t a i n e d a t i m p a c t e l e c t r o n e n e r g i e s f r o m t h r e s h o l d t o 20 k e V f o r 1^1S→n^1 P , t o 1 k e V f o r 2^3S→2^3 P a n d t o 2 k e V f o r 2^3S→3^3 P a n d 2^3P→3^3 S .