A spark plug of the present invention is made of an Ir alloy including a specific amount of Rh, Pt, or Rh and Pt or Rh and Ru. Angled optics, or a prism, may be used to direct the projections onto the single focal area. Physical action is provided in the wafer cleaning system either by way of inert gas bubbling through a baffle or by way of ultrasonic energy applied by transducers located in the tank. Each of the clutches and the brakes are located within specific areas defined by the planetary gear sets and the housing walls. Amplitude correction is applied to common image gathers and the images and common image gathers are stored on non-transitory computer-readable media.