Imaging Hypervelocity Impacts of Micro Meteorites

A new technical article from Specialised Imaging Ltd. describe a novel imaging solution for visualising the pre and post impact phenomenon of sub-millimetre projectiles travelling at hypervelocities.

The White Sands Test Facility (WSTF) Remote Hypervelocity Test Laboratory (RHTL)) (Las Cruces, NM, USA) has, for many years, used film cameras running at fixed framing speeds to record hypervelocity micro-particle impacts such as may cause problems in satellites and vehicles used in space. Whilst film cameras are able to cope with deviations from the expected velocity of micro-projectiles - they are typically large, require considerable manpower to run, have limited framing speeds / exposure times and require special optical systems and dedicated laser illumination systems to operate. A new generation of multi-frame intensified CCD cameras that operate faster, are easier to use and offer shorter exposure times are now the tool of choice for recording hypervelocity events. However with fewer frames to record the hypervelocity event it is critical that the timing of the arrival of the micro-projectile is extremely accurate such that the frame sequence coincides with the arrival of the projectile prior to the impact.

Application article 11 describes the use by NASA researchers of two SIMX8 Ultra High Speed Framing Cameras, manufactured by Specialised Imaging Ltd., for capturing and analysing framing sequences of these hypervelocity impact events. To deliver ultra high spatial resolution imaging of framing sequences of micro-projectiles travelling in excess of 8 km / second - absolutely correct timing was ensured by a new and novel SURESHOTâ„¢ triggering technique developed by Specialised Imaging Ltd. Full details of the hypervelocity impact experiment and novel triggering technique are described.

The article demonstrates how the SURESHOT triggering system has improved the timing accuracy of their hypervelocity impact experiments to nearly 100%. Using this major technical advance the NASA researchers are able to routinely capture different sequences of framing data enabling the velocity, shape, size, orientation and integrity of the fast travelling micro-projectile to be calculated.

Unlike many traditional ultra fast framing cameras the optical design of the SIMX provides the choice of up to 16 separate optical channels without compromising performance or image quality. Effects such as parallax and shading, inherent in other designs, are eliminated and the high spatial resolution (> 50 lp/mm) is the same from frame to frame and in both axes. Individual ultra-high resolution intensified CCD detectors, controlled by state-of-the-art electronics, offer almost infinite control over gain and exposure allowing researchers total freedom to capture images of even the most difficult transient phenomena.

Specialised Imaging Ltd. is a knowledgeable, dynamic company focused upon design, manufacture, service and supply of ultra high-speed imaging systems and components for industrial, defence and scientific applications.

For further information on this application please contact Specialised Imaging Ltd on telephone +44 (0) 1442 827 728 / +1-951-693-2148 or email info@specialised-imaging.com.