TY - JOUR
T1 - Shock Initiation Microscopy with High Time and Space Resolution
AU - Bassett, Will P.
AU - Johnson, Belinda P.
AU - Salvati, Lawrence
AU - Nissen, Erin J.
AU - Bhowmick, Mithun
AU - Dlott, Dana D.
N1 - The research described in this study is based on work at the University of Illinois, supported by the Department of Energy (subcontract from Lawrence Livermore Laboratory) under awards LLNL B626875 and LLNL B631306, the US Army Research Office under award W911NF‐19‐1‐0037, and the US Air Force Office of Scientific Research under award FA9550‐16‐1‐0042. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE‐AC52‐07NA27344 and was supported by the LLNL‐LDRD Program under Project No. 18‐SI‐004. Erin J. Nissen acknowledges support from the DOE NNSA Stewardship Science Graduate Fellowship under cooperative agreement number DE‐NA0002135. Belinda P. Johnson acknowledges support from the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE – 1144245 and the Alfred P. Sloan Foundation's Minority Ph.D. (MPHD) Program, awarded in 2016. SEM images were collected in the Materials Research Laboratory Central Research Facilities at UIUC. CT data were taken at the Microscopy Suite at the Beckman Institute for Advanced Science and Technology at UIUC.
The research described in this study is based on work at the University of Illinois, supported by the Department of Energy (subcontract from Lawrence Livermore Laboratory) under awards LLNL B626875 and LLNL B631306, the US Army Research Office under award W911NF-19-1-0037, and the US Air Force Office of Scientific Research under award FA9550-16-1-0042. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was supported by the LLNL-LDRD Program under Project No. 18-SI-004. Erin J. Nissen acknowledges support from the DOE NNSA Stewardship Science Graduate Fellowship under cooperative agreement number DE-NA0002135. Belinda P. Johnson acknowledges support from the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE ? 1144245 and the Alfred P. Sloan Foundation's Minority Ph.D. (MPHD) Program, awarded in 2016. SEM images were collected in the Materials Research Laboratory Central Research Facilities at UIUC. CT data were taken at the Microscopy Suite at the Beckman Institute for Advanced Science and Technology at UIUC.
PY - 2020/2/1
Y1 - 2020/2/1
N2 - We describe studies of shock initiation and shock-to-detonation transitions in energetic materials using a tabletop shock compression microscope with nanosecond time resolution and micrometer spatial resolution. Planar input shocks with durations of 4–20 ns are produced using 0–4.5 km/s laser-launched flyer plates. Emphasis is on measurements of temperature, velocities, pressure, and microstructure using photon Doppler velocimetry (PDV), optical pyrometry and high-speed videography. Techniques are discussed for fabricating disposable shock target arrays of tiny plastic-bonded explosives (PBX), liquid and powder explosives, and single-crystal explosives for high-throughput studies. Optical temperature measurements of shocked triaminotrinitrobenzene (TATB) are discussed. Since TATB is yellow, we developed methods to correct for the blue absorption to obtain more accurate temperatures. Hot spots in shocked polymer-encased HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) crystals are observed in real-time, showing a hot spot produced in a collapsing void that ignites a deflagration. Despite the small dimensions of our explosive charges (typically 1 mm diameter and 250 μm length), we produced reproducible detonation states in solid and liquid explosives using short-duration shocks near the von Neumann spike (VNS) pressure. We show the VNS pressure is associated with a transition to high-efficiency gas production from the explosives. In studies of NM, prior to detonation, we see reaction originating at hot spots which coalesce to form a superdetonation.
AB - We describe studies of shock initiation and shock-to-detonation transitions in energetic materials using a tabletop shock compression microscope with nanosecond time resolution and micrometer spatial resolution. Planar input shocks with durations of 4–20 ns are produced using 0–4.5 km/s laser-launched flyer plates. Emphasis is on measurements of temperature, velocities, pressure, and microstructure using photon Doppler velocimetry (PDV), optical pyrometry and high-speed videography. Techniques are discussed for fabricating disposable shock target arrays of tiny plastic-bonded explosives (PBX), liquid and powder explosives, and single-crystal explosives for high-throughput studies. Optical temperature measurements of shocked triaminotrinitrobenzene (TATB) are discussed. Since TATB is yellow, we developed methods to correct for the blue absorption to obtain more accurate temperatures. Hot spots in shocked polymer-encased HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) crystals are observed in real-time, showing a hot spot produced in a collapsing void that ignites a deflagration. Despite the small dimensions of our explosive charges (typically 1 mm diameter and 250 μm length), we produced reproducible detonation states in solid and liquid explosives using short-duration shocks near the von Neumann spike (VNS) pressure. We show the VNS pressure is associated with a transition to high-efficiency gas production from the explosives. In studies of NM, prior to detonation, we see reaction originating at hot spots which coalesce to form a superdetonation.
KW - imaging
KW - molecular explosives
KW - pyrometry
KW - shock compression
KW - velocimetry
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U2 - 10.1002/prep.201900222
DO - 10.1002/prep.201900222
M3 - Article
AN - SCOPUS:85078810157
SN - 0721-3115
VL - 45
SP - 223
EP - 235
JO - Propellants, Explosives, Pyrotechnics
JF - Propellants, Explosives, Pyrotechnics
IS - 2
ER -