A line narrowed gas discharge laser system and method of operation are disclosed which may comprise: an oscillator cavity; a laser chamber comprising a chamber housing containing a lasing medium gas; at least one peaking capacitor electrically connected to the chamber housing and to a first one of a pair of electrodes; a second one of the pair of electrodes connected to an opposite terminal of the at least one peaking capacitor; a current return path connected to the chamber housing; the one terminal, the first one of the electrodes, the lasing medium gas, the second one of the electrodes, the current return path and the second terminal forming a head current inductive loop having an inductance unique to the particular head current inductive loop; a spectral quality tuning mechanism comprising a mechanism for changing the particular head current inductive loop inductance value for the particular head current inductance loop.