( ( The process ) ( ( is ( ( the reflection ) ( of ( ( the ( ambient ( plasma ions ) ) ) ( under ( ( elastic collisions ) ( with ( ( ( the ( neutral ( gas jet ) ) ) , ) ( which ( we ( consider ( in ( section 4.3 ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN process)) (VP (VBZ is) (NP (NP (DT the) (NN reflection)) (PP (IN of) (NP (NP (DT the) (JJ ambient) (NN plasma) (NNS ions)) (PP (IN under) (NP (NP (JJ elastic) (NNS collisions)) (PP (IN with) (NP (NP (DT the) (JJ neutral) (NN gas) (NN jet)) (, ,) (SBAR (WHNP (WDT which)) (S (NP (PRP we)) (VP (VBP consider) (PP (IN in) (NP (NN section) (CD 4.3)))))))))))))) (. .)))
The process is the reflection of the ambient plasma ions under elastic collisions with the neutral gas jet, which we consider in section 4.3.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NN gas) (NNS particles)) (VP (VBP collide)))) (, ,) (NP (DT these) (NNS collisions)) (VP (VBP are) (VP (VBN considered) (S (ADJP (JJ elastic))))) (. .)))