ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A large area shock target array was fabricated. By moving the array through a ps pulsed laser beam, shock waves could be reproducibly generated at a high repetition rate of up to ten shocks per second. The dynamics of shock wave propagation through various layers of the array were studied using optical nanogauges. A nanogauge is a sub micron thick layer whose optical properties are affected when the shock front passes through the layer. Since shock velocities are typically a few nm/ps, nanogauges can be used to study picosecond time scale shock dynamics. Using picosecond optical microscopy on targets with different thickness aluminum layers, it was found that the shock required 0.5 ns to form and then it propagated for a few ns with a constant velocity of 8.3 km/s (8.3 nm/ps), indicating a shock pressure of 49 GPa. The arrival time jitter of many hundreds of shocks, at an aluminum/polymer interface was found to be ±50 ps. The shock propagation through a polymer, polyester, was studied by observing the arrival of the front at a 50 nm thick nanogauge embedded in the polymer. When the shock was transmitted from the aluminum to a polymer layer, its velocity was 5.5 km/s, indicating a shock pressure of 14 GPa, in good agreement with shock impedance calculations. The shock target array is a flexible method of studying picosecond time scale dynamics of materials at and just behind the shock front. The use of different optical nanogauges, such as dye-doped polymer films, which can sense the temperature, pressure, and which indicate multiphonon up pumping, is briefly discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.355788
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