Title: Observation of Variations in Condensed Carbon Morphology Dependent on Composition B Detonation Conditions

Abstract

Carbon particulates generated during detonation depend upon high explosive type, composition, and detonation conditions. Although explosive composition greatly affects particulates, the focus of this work is on how detonation geometries that induce much higher temperatures and pressures in the high explosive lead to differing particulate morphologies. In this study, two geometries were used: Detonations were initiated in Composition B cylinders at one end in conventional detonations and initiated at both ends to produce colliding detonations. Each of these detonations was observed on the sub-μs timescale using fast radiography capturing images of the front moving through the cylinder, and colliding detonation fronts in real-time. These imaging experiments were complemented with time-resolved small-angle x-ray scattering (SAXS) experiments that were able to observe and determine the varying condensed carbon morphologies at different locations and times in each detonation. The detonations could be timed in such a way that the spatial and temporal dependence of the carbon morphology could be superimposed onto radiography images collected at the same point in time. The complementary approach is able to show that the carbon condensates are much larger when formed in the elevated temperature and pressure conditions near the location of colliding detonation fronts. Thermochemical modeling suggestsmore » that these larger particulates form either in the diamond phase or on the liquidus line of the carbon phase diagram. The increase in size observed by SAXS may correlate well with the increased residence time deeply in the diamond phase. Finally, these particulates can be described as nano-sized phases with some surface texture or otherwise near-surface intra-particle heterogeneity.« less

Authors:

Hammons, Joshua A. ^[1]; Nielsen, Michael H. ^[1]; Bagge‐Hansen, Michael ^[1]; Lauderbach, Lisa M. ^[1]; Hodgin, Ralph L. ^[1]; Bastea, Sorin ^[1]; Fried, Laurence E. ^[1]; Cowan, Matthew R. ^[1]; Orlikowski, Daniel A. ^[1]; Willey, Trevor M. ^[1]

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+ Show Author Affiliations

1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:

2020-01-30

Research Org.:

Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1668476

Alternate Identifier(s):

OSTI ID: 1602903

Report Number(s):

LLNL-JRNL-778657
Journal ID: ISSN 0721-3115; 971671

Grant/Contract Number:  

AC52-07NA27344

Resource Type:

Accepted Manuscript

Journal Name:

Propellants, Explosives, Pyrotechnics

Additional Journal Information:

Journal Volume: 45; Journal Issue: 2; Journal ID: ISSN 0721-3115

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; chemical explosives; detonation nanodiamond; composition B; small-angle x-ray scattering; transmission electron microscopy; thermochemical modeling