| الوصف: |
Photonic Doppler Velocimetry (PDV) has become widely and routinely used in many high-velocity experimental applications due to its improved ease of use, cost, experimental flexibility, data return, and robustness compared to earlier velocimetric methods. However, these earlier methods have advantages in applications with requirements beyond PDV’s current capabilities. Various classes of experiments at the National Ignition Facility (NIF) that are characterized by extremely high velocity or acceleration, or diagnostic requirements for high precision in timing and/or velocity, have historically seen a VISAR (velocity interferometer system for any surface) diagnostic employed due to such advantages. VISAR, however, requires specific, and sometimes challenging, experimental features, including planar geometry and normal incidence, high-reflectivity surface treatment, and a relatively large and inflexible diagnostic footprint. Therefore, the potential for implementing a PDV diagnostic at NIF has been evaluated by researchers from National Security Technologies, LLC and Lawrence Livermore National Laboratory. We present the results of this study, weigh the relative merits of the two methodologies with consideration of experimental phenomena and requirements, and discuss possible implementations and future directions. |