not go past the radial channel 202 on the cavity pull rod 100 in other words the cavity pull rod 100 is dipped into the melt 404 a distance that is less than or equal to the distance d 1 that the radial channel is from the edge 204 of the first end 200 of the cavity pull rod 100 at 508 gas from the melt 404 is vented through the second cavity 208 which as mentioned above reduces the amount of nucleation sites thereby reducing polycrystalline development through the crystal thus at 510 the double cavity configuration of the cavity pull rod 100 results in the formation of a single crystal in situ in part due to the solidified material of the cavity at 512 the cavity pull rod 100 is extracted from the melt 404 in a direction indicated by the arrow a 1 and is simultaneously rotated in a counter clockwise direction indicated by the arrow a 2 at 514 as the cavity pull rod 100 is being extracted the thermal gradient rate of extraction and rate of rotation are precisely controlled thus at 516 resulting in the growth of a single crystal ingot 408 in situ until the melt 404 is exhausted as described above a single crystal is formed without the use of a seed crystal due to the double cavity configuration of the cavity pull rod 100 thus the single crystal is formed in situ what has been described above includes examples of the innovation it is of course not possible to describe every conceivable combination of components or methodologies for purposes of describing the subject innovation but one of ordinary skill in the art.