Abstract: A modified laser tube including a second pinch off tube or port for flowing argon and krypton gas through the laser for processing to remove contaminants to improve performance of new and used tubes such as ALC 60X argon ion lasers. Lasing discharge is maintained during processing to release contaminants for removal by plasma scrubbing of the laser bore. A magnetic field is applied and rotated in a plane perpendicular to the laser during discharge to enhance contamination release during plasma scrubbing. Preliminary cathode activation, control of gas flow rates and tube power as well as alternating of argon and krypton gas controls the contaminant release rate to prevent recontamination of the laser by released contaminants before removal.