Target Carrousel

• Stepper motor: This is a rectangular motor with an indexing knob at the back side of the motor. The indexing knob indicates the angular position of the motor shaft and hence the position of the targets.
• Target turret: This circular part accepts 6 target holders which are fitted to the shaft with a set screw (Grub screw). Targets are to be glued to these holders. This turret houses bearings, gears etc which enables the positioning and rotation of targets as required. This also has an aluminium cover to protect the bearings from getting heated due to the proximity to the substrate heater.
• Target shield: this is a thin sheet mounted on two studs with a single opening for exposing the desired target to the laser. This shield prevents material ablated from one target getting deposited on the other targets. Also this prevents heat from the substrate heater reaching the unexposed targets.