A recording apparatus includes a conveying mechanism control unit which performs a first processing and a second processing almost simultaneously, when it is detected that a recording medium has reached a stop position. An acoustic logging is performed during movement of the acoustic logging tool together with simultaneous thermal treatment of the formation. A third magnetic field sensor of the sensor system detects a third magnetic field component, which is oriented in the direction of the rotation axis. The system may be arranged such that a light beam from the amplifier medium which is re-imaged into the amplifier medium is spatially separated from itself at at least one point in its path between passes of the amplifier medium in order that it can be intercepted by additional light directing optical components, such as a prism.