Effect of current and temperature on charged particle (6)
I believe the answer is:
action
'effect' is the definition.
(thesaurus)
'current and temperature on charged particle' is the wordplay.
'current' becomes 'ac' (alternating current).
'and' is a charade indicator (letters next to each other).
'temperature' becomes 't' (abbreviation).
'on' means one lot of letters go next to another.
'charged particle' becomes 'ion' (I've seen this before).
'ac'+'t'+'ion'='ACTION'
'of' is the link.
(Other definitions for action that I've seen before include "Lawsuit; thing done" , "Fighting - lawsuit" , "Deed - lawsuit - battle" , "Jarndyce and Jarndyce, say" , "Battle (in the law courts?)" .)