Real time measurement of shock pressure
AssigneeThe United States of America as represented by the United States Deparment of Energy
InventorsRobert K. Sander, Kirill K. Zhuravlev, Richard D. Schaller, Jeffrey M. Pietryga, Michael Whitehead
Life of this patent
Estimating the term…
Abstract
A fiber-based optical pressure-sensor, made using semiconductor nanocrystal quantum dots (NQDs) as the active transducing material, provides response time fast enough for shock wave measurements. For NQDs, the shift in band gap as a result of applied pressure can be observed as a shift of the photoluminescence (PL) peak. Further, the shift of the principal absorbance feature allows pressure measurements faster than those obtainable by following the PL peak.
Claims32
A method, comprising:
- positioning nanocrystal quantum dots (NQDs) proximate to an energetic material,
- compressing said energetic material by detonation whereby a shift in band gap is produced in said NQDs;
- and
- observing an electromagnetic product (EMP) of said shift in band gap during compression of said energetic material.
A method, comprising:
- positioning nanocrystal quantum dots (NQDs) proximate a material, wherein a shift in band gap is produced within said NQDs when said material is compressed;
- measuring the electromagnetic product (EMP) of said shift in band gap during compression of the material by transmitting said EMP to a spectrometer linked to a streak camera;
- and
- producing data from said EMP indicative of the amount of pressure within said material.
An apparatus for sensing pressure, comprising:
- a first fiber optic (FFO) comprising a FFO proximal end and a FFO distal end;
- nanocrystal quantum dots (NQDs) affixed proximately to said FFO distal end:
- an electromagnetic radiation source (EMS) for optically exciting said NQDs;
- means for aligning said EMS into said FFO proximal end;
- a spectrometer which is operatively aligned with said FFO distal end;
- and
- a streak camera which is optically aligned with said spectrometer output for measuring the shift in band gap produced within said NQDs when excited.
An apparatus for sensing pressure, comprising:
- a fiber optic splitter having an input port, an output port and a return port,
- nanocrystal quantum dots (NQDs) affixed proximately to said output port,
- a material into which is embedded said output port whereby a shift in band gap is produced in said NQDs by the shock of said material;
- a light source for directing light into the input port of said fiber optic splitter for exciting the NQDs located at the output port;
- and
- a detector located at the return port of said splitter, for receiving emitted light generated at the output port during the shock of said material and, which is coupled back down the fiber from the output port to the return port, for measuring said shift in band gap by filtering out the excitation source light.
A method for sensing pressure comprising:
- positioning nanocrystal quantum dots (NQDs) on one unclad end of a single optical fiber proximate to a material,
- directing a laser light at a wavelength that is absorbed by the NQDs into the opposite end of said optical fiber,
- producing a shift in absorption frequency in said NQDs when said material is shocked;
- and
- optically detecting the variance in light transmitted by said NQDs during shock through the use of a photodiode and oscilloscope.
Dependencies are inferred from the claim text.