Abstract: An impact attenuator including an impact head, coupled to a first end of an energy absorption body, which energy absorption body is arranged for fixation to an external structure at a second end opposing the first end of the energy absorption body, configured to at least partly absorb or dissipate energy from a collision of an object with the impact head, and including a first part and a second part extending substantially lengthwise behind each other, wherein the first and second part are mutually moveable and including a first and a second cutting edge, wherein, the first cutting edge is arranged for splitting the first part of the energy absorption body upon impact of an object colliding with the impact head, and the second cutting edge is arranged for consecutively splitting the second part of the energy absorption body upon impact of an object colliding with the impact head.

Abstract: An ultra high resolution wave focusing method and apparatus is disclosed. The invention provides a focusing system having an effective numerical aperture greater than that possible using known conventional focusing techniques. By the method and apparatus of the invention, a wave of arbitrary wavefront profile and wavelength .lambda. is focused to a region of high amplitude having a spot size that approaches the fundamental limit of 0.25.lambda.. Imaging and patterning systems employing such a wave focusing method and apparatus provide ultra high resolution and ultra small feature sizes beyond the capabilities of systems utilizing conventional focusing elements.