Ejecta Particle-Size Measurements in Vacuum and Helium Gas using Ultraviolet In-Line Fraunhofer Holography

Sorenson, D. S.¹  Pazuchanics, P.¹  Johnson, R.¹  Malone, R. M.²  Kaufman, M. I.²  Tibbitts, A.²  Tunnell, T.²  Marks, D.²  Capelle, G. A.²  Grover, M.²  Marshall, B.²  Stevens, G. 

[1] LANL;NSTec

关键词: ejecta;    particle size;    in-line Fraunhofer holography;    UV;    ultraviolet;   

DOI  :  10.2172/1170392
RP-ID  :  LA-UR-14-24722
RP-ID  :  DOE/NV/25946--2184
PID  :  OSTI ID: 1170392

美国|英语

来源: SciTech Connect

【 摘 要 】

An ultraviolet (UV) in-line Fraunhofer holography diagnostic has been developed for making high-resolution spatial measurements of ejecta particles traveling at many mm/??sec. This report will discuss the development of the diagnostic, including the high-powered laser system and high-resolution optical relay system. In addition, we will also describe the system required to reconstruct the images from the hologram and the corresponding analysis of those images to extract particles. Finally, we will present results from six high-explosive (HE), shock-driven Sn-ejecta experiments. Particle-size distributions will be shown that cover most of the ejecta velocities for experiments conducted in a vacuum, and helium gas environments. In addition, a modification has been made to the laser system that produces two laser pulses separated by 6.8 ns. This double-pulsed capability allows a superposition of two holograms to be acquired at two different times, thus allowing ejecta velocities to be measured directly. Results from this double-pulsed experiment will be described.