Examining the temporal evolution of hypervelocity impact phenomena via high-speed imaging and ultraviolet-visible emission spectroscopy

Abstract

A model for debris clouds produced by impact of hypervelocity projectiles on multiplate structures Appl. Phys. Lett. 93, 211905 (2008) Examining the temporal evolution of hypervelocity impact phenomena via high-speed imaging and ultraviolet-visible emission spectroscopy The temporal evolution of a previously observed hypervelocity impact-induced vapor cloud [Mihaly et al., Int. J. Impact Eng. 62, 13 (2013)] was measured by simultaneously recording several full-field, near-IR images of the resulting emission using an OMA-V high-speed camera. A two-stage light-gas gun was used to accelerate 5 mg Nylon 6/6 right-cylinders to speeds between 5 km/s and 7 km/s to impact 1.5 mm thick 6061-T6 aluminum target plates. Complementary laserside-lighting [Mihaly et al., Int. J. Impact Eng. 62, 13 (2013); Proc. Eng. 58, 363 (2013)] and frontof-target (without laser illumination) images were also captured using a Cordin ultra-high-speed camera. The rapid expansion of the vapor cloud was observed to contain a bright, emitting exterior, and a darker, optically thick interior. The shape of this phenomenon was also observed to vary considerably between experiments due to extremely high-rate (>250 000 rpm) of tumbling of the cylindrical projectiles. Additionally, UV-vis emission spectra were simultaneously recorded to investigate the temporal evolution of the atomic and molecular composition of the up-range, impact-induced vapor plume. A PI-MAX3 high-speed camera coupled to an Acton spectrograph was utilized to capture the UV-vis spectra, which shows an overall peak in emission intensity between approximately 6-10 ls after impact trigger, corresponding to an increased quantity of emitting vapor/plasma passing through the spectrometer slit during this time period. The relative intensity of the numerous spectral bands was also observed to vary according to the exposure delay of the camera, indicating that the different atomic/molecular species exhibit a varied temporal evolution during the vapor cloud expansion. Higher resolution spectra yielded additional emission lines/bands that provide further evidence of interaction between fragmented projectile material and the 1 mmHg atmosphere inside the target chamber. A comparison of the data to down-range emission spectra also revealed differences in the relative intensities of the atomic/molecular composition of the observed vapor clouds. V C 2014 AIP Publishing LLC.

Pressure-Dependent, Infrared-Emitting Phenomenon in Hypervelocity Impact

“…The majority of the observed IR-emission is likely produced by a relatively diffuse vapor/plasma cloud [1,15], similar to that observed by Sugita and Schultz [7,9,16]. They describe an impact-induced vapor cloud as a chemically and thermally heterogeneous entity with components each having different mass, momentum, and energy [9].…”

“…Analysis of concurrently measured UV-Vis spectra indicates strong emission in the regions of observed debris from species originating from the nylon impactor [1,15]. Such results may provide insight into the origin and composition of the observed IR-emitting phenomena.…”

“…This suggests the formation of the IR-emitting cloud is related to the debris observed with the LSL system. A thorough discussion of the size, shape, and temporal evolution of the observed IR-emitting phenomena is presented in a previous work [15].…”

Time-resolved Spectroscopy of Plasma Flash from Hypervelocity Impact on Debrisat

“…Additional molecular bands are observed between 450 nm and 570 nm, which coincide with the Swan band system; these bands are due to vibrational transitions in the A 3 g -X 3 u electronic states of the C 2 molecule [12]. These Swan bands have also been observed by others during impacts [13,14], and also during laser ablation of graphitic targets in vacuum, oxygen, and argon [15]. Sources for C 2 in this experiment are the nylon projectile, the carbon fiber composite in the face panels of the satellite, and the polymers present in multilayer insulation on the exterior of the satellite.…”

Impact flash evolution of CO2 ice, water ice, and frozen Martian and lunar regolith simulant targets

“…The temporal evolution of impact flashes is typically monitored in the laboratory using photodetectors (Eichhorn 1976;Burchell et al 1996;Ernst and Schultz 2003Bergeron et al 2006;Lawrence et al 2006;Tsembelis et al 2008;Ernst et al 2011;Goel et al 2015;Yafei et al 2019) or high-speed cameras (Kondo and Ahrens 1983;Schultz 1996;Ernst and Schultz 2007;Schultz et al 2007;Mihaly et al 2013Mihaly et al , 2015Tandy et al 2014;Schultz and Eberhardy 2015), revealing multiple phases of the radiating impact ejecta. These phases primarily comprise a rapid jet or plasma phase; a slower, expanding vapor cloud; and molten or high temperature ejecta that are dependent on specific impact parameters (Ang 1990;Yang et al 1992; Kadono and Fujiwara 1996;Schultz 1996;Sugita et al 1998;Sugita and Schultz 1999;Schultz 2004, 2007;Schultz et al 2006;Tsembelis et al 2008;Ernst et al 2011;Bruck Syal et al 2012).…”