An ingot mold has a body having an open top, a bottom with an opening, and a longitudinal cavity passing through the body. An LED drive circuit is further disclosed in the application. Also, a position displacement of the aperture 17 in the optical axis direction is detected and corrected on the basis of a change in an output of the detector 18 by oscillating the aperture 17 in the optical axis direction. Thus, if a local node has a cache miss it is implied that the other node in the system has the cache line. Once a puncture has been made, the pressure ring holds the puncture wound open to allow bleeding.