Spectroscopic determination of carbon dimer densities in and plasmas

Goyette, A. N.; Lawler, J. E.; Anderson, L. W.; Gruen, D. M.; McCauley, Thomas G.; Zhou, Dong; Krauss, A. R.

doi:10.1088/0022-3727/31/16/006

Cited by 66 publications

(61 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…43 These Swan bands are well known in carbon-rich plasma spectra originating from several sources, including high-speed impacts, the ablation of graphite, the electrical discharge of acetylene, or chemical vapor deposition. 8,10,[47][48][49][50][51] Schultz et al previously examined spectral signatures from oblique impacts into porous particulates and found evidence that Swan band emission can originate from hydrocarbon bearing targets or from the dissociation of carbon-rich compounds under low atmospheric pressure conditions. 10 Additional work by Sugita and Schultz investigated impacts of polycarbonate on water and yielded strong C 2 Swan band emission, which they attributed to a high-temperature carbon-rich vapor that was ablated from rapidly moving, fine-grain fragments in the expanding impact-induced vapor cloud.…”

Section: Fig 15mentioning

confidence: 99%

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

Tandy

Mihaly

Adams

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

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.

show abstract

Section: Fig 15mentioning

confidence: 99%

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

Tandy

Mihaly

Adams

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…Goyette et al 6 used absorption spectroscopy in parallel with OES to show a correlation between the excited C 2 (d) state and the lower C 2 (a) state while changing parameters in a microwave plasma.…”

Section: Introductionmentioning

confidence: 99%

The role of C2 in nanocrystalline diamond growth

Rabeau

Fan

John

et al. 2004

Journal of Applied Physics

View full text Add to dashboard Cite

This paper presents findings from a study of nanocrystalline diamond (NCD) growth in a microwave plasma chemical vapour deposition (CVD) reactor. NCD films were grown using Ar/H 2 /CH 4 and He/H 2 /CH 4 gas compositions. The resulting films were characterised using Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Analysis revealed an estimated grain size of the order of 50 nm, growth rates in the range 0.01 to 0.3 µm/h and sp 3 and sp 2 bonded carbon content consistent with that expected for NCD.The C 2 Swan band (d 3 П g ↔ a 3 П u ) was probed using cavity ring-down spectroscopy (CRDS) to measure the absolute C 2 (a) number density in the plasma during diamond film growth.The number density in the Ar/H 2 /CH 4 plasmas was in the range 2 to 4 x 10 12 cm -3 , but found to be present in quantities too low to measure in the He/H 2 /CH 4 plasmas. Optical emission 2 spectrometry (OES) was employed to determine the relative densities of the C 2 excited state (d) in the plasma.The fact that similar NCD material was grown whether using Ar or He as the carrier gas suggests that C 2 does not play a major role in the growth of nanocrystalline diamond.3

show abstract

“…Recent results by Gruen and coworkers [1][2][3][4][5][6][7] have shown the feasibility of depositing nanocrystalline diamond thin films from microwave (2.45 GHz) C 60 /H 2 /Ar [1,2,5] and CH 4 /H 2 /Ar [3,4,6,7] plasmas with Ar concentrations up to 97% or even without the addition of molecular hydrogen [1,4,7]. They were also able to establish concrete MW discharge conditions under which structural film changes were observed to lead from microcrystalline to nanocrystalline diamond films [6].…”

Section: Introductionmentioning

confidence: 97%