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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

SUPERNOVA EXPLOSIONS OF SUPER-ASYMPTOTIC GIANT BRANCH STARS: MULTICOLOR LIGHT CURVES OF ELECTRON-CAPTURE SUPERNOVAE

An electron-capture supernova (ECSN) is a core-collapse supernova (CCSN) explosion of a super-asymptotic giant branch (SAGB) star with a main-sequence mass M{sub MS} {approx} 7-9.5 M{sub Sun }. The explosion takes place in accordance with core bounce and subsequent neutrino heating and is a unique example successfully produced by first-principle simulations. This allows us to derive a first self-consistent multicolor light curve of a CCSN. Adopting the explosion properties derived by the first-principle simulation, i.e., the low explosion energy of 1.5 Multiplication-Sign 10{sup 50} erg and the small {sup 56}Ni mass of 2.5 Multiplication-Sign 10{sup -3} M{sub Sun }, we perform a multi-group radiation hydrodynamics calculation of ECSNe and present multicolor light curves of ECSNe of SAGB stars with various envelope masses and hydrogen abundances. We demonstrate that a shock breakout has a peak luminosity of L {approx} 2 Multiplication-Sign 10{sup 44} erg s{sup -1} and can evaporate circumstellar dust up to R {approx} 10{sup 17} cm for the case of carbon dust, that the plateau luminosity and plateau duration of ECSNe are L {approx} 10{sup 42} erg s{sup -1} and t {approx} 60-100 days, respectively, and that a plateau is followed by a tail with a luminosity drop by {approx}4 mag. The ECSN shows a bright and short plateau that is as bright as typical Type II plateau supernovae, and a faint tail that might be influenced by the spin-down luminosity of a newborn pulsar. Furthermore, the theoretical models are compared with ECSN candidates: SN 1054 and SN 2008S. We find that SN 1054 shares the characteristics of the ECSNe. For SN 2008S, we find that its faint plateau requires an ECSN model with a significantly low explosion energy of E {approx} 10{sup 48} erg.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

A method to fuse multiphysics waveforms and improve predictive explosion detection: theory, experiment and performance

Natural and human-made sources of transient energy often emit multiple geophysical signatures that include mechanical and electromagnetic waveforms. We present a constructive method to fuse and evaluate statistics that we derive from such multiphysics waveforms that improves our capability to detect small, near-ground explosions over similar methods that consume single signature waveforms. Our method advances Fisher's Combined Probability Test (Fisher's Method) to operate under both hypotheses of a binary test on noisy data and provide researchers with the density functions required to forecast the ability of Fisher's Method to screen fused explosion signatures from noise. We apply this method against 12 d, multisignature explosion and noise records to show (1) that a fused multiphysics waveform statistic that combines radio, acoustic and seismic waveform data can identify explosions roughly 0.8 magnitude units lower than an acoustic emission, STA/LTA detector for the same detection probability and (2) that we can quantitatively predict how this fused, multiphysics statistic performs with Fisher's Method. Our work thereby offers a baseline method for predictive waveform fusion that supports multiphenomenological explosion monitoring (multiPEM) and is applicable to any binary testing problem in observational geophysics.

58 GEOSCIENCES↗
DOE OSTI2018

Bayesian characterization of explosive sources using infrasonic signals

In this paper, a Bayesian approach is applied to the estimation of source characteristics for above ground explosive events using infrasonic observations at propagation distances of hundreds of kilometers. Propagation-based, stochastic path geometry models have previously been investigated for infrasonic source localization with promising results; here, statistical transmission loss models are investigated using archived atmospheric specifications and propagation simulation tools to demonstrate that such an approach is applicable to source characterization. The resulting transmission loss models models are utilized in estimating near-source spectral characteristics for explosive events from infrasonic observations at regional distances of several hundred kilometers or more using a Bayesian framework to compute a combined estimate. The near-source spectral characterization can be used along with a simplistic explosive source model to compute an estimate of explosive yield with quantifiable uncertainty. Finally, the yield estimation framework is evaluated using above-ground explosive events from the western US during the fall of 2012 with promising results.

58 GEOSCIENCES↗
DOE OSTI2021

Comparison of Surface Phenomena Created by Underground Chemical Explosions in Dry Alluvium and Granite Geology From Fully Polarimetric VideoSAR Data

Phase I of the Source Physics Experiment (SPE) series involved six underground chemical explosions, all of which were conducted at the same experimental pad. Research from the sixth explosion of the series (SPE-6) demonstrated that polarimetric synthetic aperture radar (PolSAR) is a viable technology for monitoring an underground chemical explosion when the geologic structure is Cretaceous granitic intrusive. It was shown that a durable signal is measurable by the H/A/α polarimetric decomposition parameters. After the SPE-6 experiment, the SPE program moved to the Phase II location, which is composed of dry alluvium geology (DAG). The loss of wavefront energy is greater through dry alluvium than through granite. In this article, we compare the SPE-6 analysis to the second DAG (DAG-2) experiment. We hypothesize that despite the geology at the DAG site being more challenging than at the Phase I location, combined with the DAG-2 experiment having a 3.37 times deeper scaled depth of burial than the SPE-6, a durable nonprompt signal is still measurable by a PolSAR sensor. We compare the PolSAR time-series measures from videoSAR frames, from the SPE-6 and DAG-2 experiments, with accelerometer data. We show which PolSAR measures are invariant to the two types of geology and which are geology dependent. We compare a coherent change detection (CCD) map from the DAG-2 experiment with the data from a fiber-optic distributed acoustic sensor to show the connection between the spatial extent of coherence loss in CCD maps and spallation caused by the explosion. Finally, we also analyze the spatial extent of the PolSAR measures from both explosions.

42 ENGINEERING↗
DOE OSTI2022

Lithologic controls on microfracturing from legacy underground nuclear explosions

Detection and verification of underground nuclear explosions (UNEs) can be improved with a better understanding of the nature and extent of explosion-induced damage in rock and the effect of this damage on radionuclide migration. Much of the previous work in this area has focused on centimeter- to meter-scale manifestations of damage, but to predict the effect of damage on permeability for radionuclide migration, observations at smaller scales are needed to determine deformation mechanisms. Based on studies of tectonic deformation in tuff, we expected that the heterogeneous tuff layers would manifest explosion-induced damage differently, with welded tuffs showing more fractures and nonwelded tuffs showing more deformation bands. In comparing post-UNE samples with lithologically matched pre-UNE equivalents, we observed damage in multiple lithologies of tuff through quantitative microfracture densities. We find that the texture (e.g., from deposition, welding, alteration, etc.) affects fracture densities, with stronger units fracturing more than weaker units. While we see no evidence of expected deformation bands in the nonwelded tuffs, we do observe, as expected, much larger microfracture densities at close range (<50 m) to the explosive source. We also observe a subtle increase in microfracture densities in post-UNE samples, relative to pre-UNE equivalents, in all lithologies and depths. The fractures that are interpreted to be UNE-induced are primarily transgranular and grain-boundary microfractures, with intragranular microfracture densities being largely similar to those of pre-UNE samples. This work has implications for models of explosion-induced damage and how that damage may affect flow pathways in the subsurface.

58 GEOSCIENCES↗
DOE OSTI2025

Full‐Waveform Simulation of Infrasound Propagation in the Atmosphere: A Case Study of the 2023 April 20 SpaceX Starship Explosion

Infrasound, low‐frequency sound below 20 Hz, has been a key technology to monitor explosion events in the atmosphere. The International Monitoring System (IMS) of the Comprehensive Nuclear‐Test‐Ban Treaty Organization provides the means for continuous monitoring of infrasonic events worldwide. Infrasonic techniques for event location and size estimation can also complement other observational techniques for the detection and characterization of the entry of asteroids or large meteoroids. In this study, we describe the detection capability of IMS infrasound stations for an explosive event in the middle of the atmosphere. Full‐waveform simulations are performed with the specification of atmospheric conditions and incorporated into the event location and explosion yield estimation. We applied it to the 2023 April 20 SpaceX Starship explosion at 29 km altitude. Starship is a super heavy‐lift space vehicle constructed by SpaceX and known as the largest and most powerful rocket ever built. The Starship explosion created huge pressure disturbances in the atmosphere, and its infrasound was detected by the IMS arrays in North America between 2000 and 4000 km. Independent observational data and available ground‐truth information provide a rare opportunity to evaluate the monitoring capability of the IMS network for elevated sources in the atmosphere. We also demonstrate the capability of full‐waveform simulation for infrasound wavefield characterization and prediction to improve event location and yield estimation.

Geosciences↗
DOE OSTI2015

Analysis of Ground Motion from An Underground Chemical Explosion

Here in this paper we investigate the excitation and propagation of far-field seismic waves from the 905 kg trinitrotoluene equivalent underground chemical explosion SPE-3 recorded during the Source Physics Experiment (SPE) at the Nevada National Security Site. The recorded far-field ground motion at short and long distances is characterized by substantial shear-wave energy, and large azimuthal variations in P-and S-wave amplitudes. The shear waves observed on the transverse component of sensors at epicentral distances <50 m suggests they were generated at or very near the source. The relative amplitude of the shear waves grows as the waves propagate away from the source. We analyze and model the shear-wave excitation during the explosion in the 0.01–10 Hz frequency range, at epicentral distances of up to 1 km. We used two simulation techniques. One is based on the empirical isotropic Mueller–Murphy (MM) (Mueller and Murphy, 1971) nuclear explosion source model, and 3D anelastic wave propagation modeling. The second uses a physics-based approach that couples hydrodynamic modeling of the chemical explosion source with anelastic wave propagation modeling. Comparisons with recorded data show the MM source model overestimates the SPE-3 far-field ground motion by an average factor of 4. The observations show that shear waves with substantial high-frequency energy were generated at the source. However, to match the observations additional shear waves from scattering, including surface topography, and heterogeneous shallow structure contributed to the amplification of far-field shear motion. Comparisons between empirically based isotropic and physics-based anisotropic source models suggest that both wave-scattering effects and near-field nonlinear effects are needed to explain the amplitude and irregular radiation pattern of shear motion observed during the SPE-3 explosion.

58 GEOSCIENCES↗
DOE OSTI2016

Generation of Shear Motion from an Isotropic Explosion Source by Scattering in Heterogeneous Media

One challenging task in explosion seismology is the development of physical models for explaining the generation of S waves during underground explosions. Recent analysis of ground motion from chemical explosions during the Source Physics Experiment (Pitarka et al., 2015) suggests that, although a large component of shear motion was generated directly at the source, additional scattering from heterogeneous velocity structure and topography is necessary to better match the recorded data. In our paper, we used a stochastic representation of small-scale velocity variability to produce high-frequency scattering and to analyze its implication on shear-motion generation during underground explosions. In our stochastic velocity model, the key parameters that affect scattering are the correlation length and the relative amplitude of velocity perturbations. Finally, based on finite-difference simulations of elastic wave propagation from an isotropic explosion source, we find that higher velocity perturbations result in larger shear motion, whereas the correlation length, which controls the scatterers size, affects the frequency range at which relative transverse motion is larger.

58 GEOSCIENCES↗
DOE OSTI2023

Numerical Modeling of Air-Blast Suppression as a Function of Explosive-Charge Burial Depth

As a chemical explosion is buried, the mechanism for acoustic wave generation transitions from fully gas-generated at the surface to completely spall-induced at full containment depth. The fully gas-generated and completely spall-induced signals in the acoustic waveform are well described; however, the transition between these two end-members eludes numerical modeling because of the complex phenomena that are involved. The phenomena of crater formation and explosive cloud evolution are simulated using an Eulerian hydrocode that incorporates geomaterials with strength and porosity. Having accurately modeled these phenomena, we can confidently predict the propagation and relative strength of the gas-generated and spall-induced pulses in the recorded acoustic waveform. The numerical predictions agree with observations from the historical Stagecoach experiment as well as modern recordings from the Source Physics Experiment. In particular, the peak pressure p generated by an explosion is initially due to the gas-generated mechanism and decays with scaled depth of burial d s (depth d scaled by the cube-root of explosive yield w 1/3 ) as exp(-d s ) but then transitions near a scaled depth of 6 m/ton 1/3 to the spall-generated mechanism in which the decay is d$_{s}^{-7/4}$. This decay form is related to the strong ground-motion attenuation relationship that affects spall strength. So these results can improve seismoacoustic inverse models for the explosive source that need to account for the gas-generated and spall-induced signals and their effect on peak pressures and other acoustic signal features.

58 GEOSCIENCES↗
DOE OSTI2023

Seismoacoustic Analysis of the Large Surface Explosion Coupling Experiment Using a Large- N Seismic Array

Seismoacoustic signals at local distance (<~10 km) are widely used as important constraints on source parameters for near-surface events, yet the seismoacoustic wave generation and energy partitioning are not fully understood. Spatially dense sensors could provide observations in high resolution to capture the full wavefield for better understanding wave propagation and improving source estimation. Recently, spatially dense observations of the local seismoacoustic wavefield produced by a pair of 1-ton surface explosions have been recorded using a large-N seismic array. This large-N array consists of 446 geophones and covers an area of approximately 2×2.5 km 2 . The two surface explosions occur at the same location but at different times with different atmospheric conditions. Both seismic and air–ground coupled acoustic waves from the two surface explosions are well observed. Analyses of signals recorded by the large-N seismic array show different acoustic wave speed and amplitude for the two explosions. A strong spatial variability in acoustic wave speed and amplitude for each explosion is also observed. Finally, the observations suggest the important role of local atmosphere state on wave propagation and source estimation and demonstrate how the use of a large-N capability can improve characterization of the propagation medium and source.

58 GEOSCIENCES↗
DOE OSTI2024

Spatially Dependent Seismic Wavefield Scattering from an Underground Chemical Explosion: Analysis of the Source Physics Experiment Dry Alluvium Geology Large- N Array

Explosion sources have been observed to generate significant shear‐wave energy despite their isotropic nature. To investigate this phenomenon, we conduct an analysis of the seismic data collected as part of the Source Physics Experiment (SPE): Dry Alluvium Geology (DAG) and investigate the generation of shear‐wave energy via scattering. The data were produced by three underground chemical explosions and consist of three‐component seismograms, which were recorded by the DAG Large‐N array. Synthetic tests suggest that for the DAG experiments, small‐scale stochastic heterogeneities, defined as features with correlation lengths of 10–100s of meters, are more effective than large‐scale geologic structure (scales >1–10 km) at reproducing the scattering of explosion generated wavefields observed at DAG. We analyze the seismic data for spatially variable ratios between transversely and radially polarized seismic energy, and then estimate the mean free path of P and S waves. All analyses are conducted within a frequency band of 5–50 Hz. The ratio of transversely to radially polarized energy is the highest in the east and west portion of the Large‐N array. In addition, the magnitude of the estimated S‐wave mean free path is shorter in the eastern portion of the Large‐N array. This variation indicates that the eastern area of the DAG array is where more scattering is occurring, suggesting azimuthal dependence of P‐to‐P and P‐to‐S scattering. Furthermore, this azimuthal dependence of P‐to‐S scattering can have implications for explosion discrimination based on spectral ratios of seismic wave types, because the general assumption is that explosions do not generate shear‐wave energy. Synthetic tests modeling only larger‐scale geologic structure had lower transversely polarized energy (only four stations showing a transversely to radially polarized energy ratio greater than 1) and fewer stations (<10) displaying shorter (<300 m) mean free paths than what was observed in the DAG data results.

Darrh, Andréa Nicole↗
DOE OSTI2014

In-Situ Silver Acetylide Silver Nitrate Explosive Deposition Measurements Using X-Ray Fluorescence.

The Light Initiated High Explosive facility utilized a spray deposited coating of silver acetylide - silver nitrate explosive to impart a mechanical shock into targets of interest. A diagnostic was required to measure the explosive deposition in - situ. An X - ray fluorescence spectrometer was deployed at the facility. A measurement methodology was developed to measure the explosive quantity with sufficient accuracy. Through the use of a tin reference material under the silver based explosive, a field calibration relationship has been developed with a standard deviation of 3.2 % . The effect of the inserted tin material into the experiment configuration has been explored.

Covert, Timothy Todd↗
DOE OSTI2016

Supplemental Environmental Baseline Survey for Proposed Land Use Permit Modification for Expansion of the Dynamic Explosive Test Site (DETS) 9940 Main Complex Parking Lot

The “subject property” is comprised of a parcel of land within the Kirtland Military Reservation, Bernalillo County, New Mexico, as shown on the map in Appendix B of this document. The land requirement for the parking lot addition to the 9940 Main Complex is approximately 2.7 acres. The scope of this Supplemental Environmental Baseline Survey (SEBS) is for the parking lot addition land transfer only. For details on the original 9940 Main Complex see Environmental Baseline Survey, Land Use Permit Request for the 9940 Complex PERM/0-KI-00-0001, August 21, 2003, and for details on the 9940 Complex Expansion see Environmental Baseline Survey, Proposed Land Use Permit Expansion for 9940 DETS Complex, June 24, 2009. The 2.7-acre parcel of land for the new parking lot, which is the subject of this EBS (also referred to as the “subject property”), is adjacent to the southwest boundary of the original 12.3- acre 9940 Main Complex. No testing is known to have taken place on the subject property site. The only activity known to have taken place was the burial of overhead utility lines in 2014. Adjacent to the subject property, the 9940 Main Complex was originally a 12.3-acre site used by the Department of Energy (DOE) under a land use permit from the United States Air Force (USAF). Historical use of the site, dating from 1964, included arming, fusing, and firing of explosives and testing of explosives systems components. In the late 1970s and early 1980s experiments at the 9940 Main Complex shifted toward reactor safety issues. From 1983 to 1988, fuel coolant interaction (FCI) experiments were conducted, as were experiments with conventional high explosives (HE). Today, the land is used for training of the Nuclear Emergency Response community and for research on energetic materials. In 2009, the original complex was expanded to include four additional 20-acre areas: 9940 Training South, 9940 Training East, T-Range 6, and Training West Landing Zone. The proposed use of the subject property is for the purpose of adding a parking lot to serve the increase in customer vehicles that is occurring as the 9940 Main Complex is more heavily utilized, and as the 2009 Expansion areas come online as operational training facilities. The subject property would be used only for parking, not for testing or training activities. The parking lot would have a gravel surface. Current and future work at the 9940 Main Complex involves arming, fuzing, and firing of explosives and the testing of explosive systems components in both terrestrial and aquatic settings. It also involves specialized training activities for a variety of first responder customers, both DOE and non-DOE agencies. The approach was to perform a document search, supplemented by a visual site inspection, to identify potential environmental contamination associated with the property. Factors evaluated included hazardous substances; petroleum products and derivatives; environmental restoration sites; areas of concern; storage tanks; oil/water separators; grease traps; wash racks; waste tanks; pesticides; military munitions/ordnance; medical or bio-hazardous waste; radioactive waste; solid/municipal waste; indoor air quality; groundwater; wastewater treatment, collection, and disposal/discharge; drinking water quality; utilities; asbestos; polychlorinated biphenyls (PCBs); radon; lead-based paint; cultural resources; floodplains; and natural/biological resources. Each of these factors is evaluated separately in Section 5, Findings for Subject Property. The property categorization for this subject property would be considered Category 1- “An area or real property where no storage, release, or disposal of hazardous substances or petroleum products or their derivatives has occurred into the environment or structures or disposed on the subject property (including no migration of these substances from adjacent properties).” There appears to be sufficient information to categorize the subject property and it appears that no further effort needs to be made to obtain additional information. There are no findings of an adverse nature on the subject property itself or from adjacent properties. It is recommended that the proposed transfer of the subject property from the USAF to DOE proceed.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Modeling Astrophysical Explosions and the Nucleosynthesis of the Heavy Elements

The heavier elements in the Universe were created and dispersed in the supernova explosions of stars. These events involve a fascinating interplay of nuclear physics, gravity, hydrodynamics, neutrino and photon transport, and radioactive decay, all occurring under extreme conditions. Astronomical experiments provide a rich and constraining data set, but our theoretical understanding of supernovae remains incomplete. The goal of this project is to advance numerical models of astrophysical explosions and use them to connect the nuclear theory of supernovae to current observational and experimental programs. Our contributions focus on one important aspect of the problem --modeling the transport of radiation (both neutrino and electromagnetic) which is essential to understanding the supernova explosion mechanism, the resulting nucleosynthesis, and the observable spectra and light curves. We will exploit recent advances in high performance computing to improve 3-dimensional simulations of core collapse supernovae and neutron star mergers. The benefits include: 1) Further defining the explosive astrophysical environments that govern the nucleosynthesis of r-process nuclei. 2) Preparing the way for more realistic treatments of neutrino interactions, with the ultimate goal of making supernovae a testing ground for probing fundamental neutrino physics, e.g., unknown mixing angles and new aspects of the MSW mechanism. 3) Providing a means for testing explosion simulations and nucleosynthesis calculations against data from optical and x-ray telescopes, thereby permitting the experimental validation or falsification of supernova models. 4) Helping position nuclear physics, through the development of new algorithms of the type incorporated in our simulation codes, to play a leading role in DOE large scale computing.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

PBX-9501 High Explosive Infrared Thermography Test Report

High explosive safety requirements put in place by the Department of Defense necessitate that Los Alamos National Laboratory verify that high melting explosive-based plastic bonded explosive 9501 will not present a health or safety risk to personnel when exposed to various accident scenarios. The JT5R-14C test is being developed to validate this requirement in a scenario where PBX-9501 is exposed to a hydrocarbon fuel fire. Preliminary testing is required to establish benchmark data on the burning characteristics of PBX-9501. The PBX-9501 High Explosive Infrared Thermography test was designed to provide the benchmark burning characteristics of PBX-9501 in a simulated fuel fire environment using propane burners as a fuel source. The PBX-9501-HEIT was successfully completed using a 20.32 cm tall cylindrical sample of PBX-9501 with a radius of 10.16 cm, a volume of 6,589.63 cm 3 , a density of 1.83 g/cm 3 , and a mass of 1.2 kg. The PBX-9501-HEIT test was captured and recorded video sequence using a Telops Inc., Multispectral Infrared camera. The infrared sequence was reviewed to identify key events throughout the test and serves as a visual tool to cross reference against future testing to aid in the identification of PBX-9501 high explosive ignition and deflagration characteristics. The data obtained in the thermographic sequence confirmed that the temperatures emitted by the PBX-9501 were higher than the temperatures of the propane burner ignition source. The propane burner flames had a temperature range of 700-850 °C. The cylindrical sample of PBX-9501 burned at an average temperature of 1000-1200 °C on the surface with off-gassing temperatures averaging 1100-1250 °C. The heat map of the PBX-9501 obtained through the test was between 250-550 °C higher than the propane gas temperatures. The temperature differential between the PBX-9501 and the propane flame allowed for the identification of key burning features.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2019

3D Moment Tensor Inversion of Underground Chemical Explosions from the Source Physics Experiments

Several physical mechanisms have been proposed to explain the generation of S-waves from underground explosions, such as asymmetries in the source, release of tectonic pre-stress, interactions with the free-surface, spall, and heterogeneities in the Earth. An accurate description of the explosion source processes is an important step towards understanding which of these plausible mechanisms are actively contributing to the generation of S-waves and under what conditions. In this study we explore the application of the seismic moment tensor source to model far-field, low frequency (up to 6 Hz) waveform data of over-buried chemical explosions from the Source Physics Experiment, with a focus on S-wave generation and amplitude predictions. We use an inverse waveform modeling approach to estimate the source properties of the chemical explosions, and compare solutions using different velocity models. 1D and 3D subsurface velocity models are used to characterize wave propagation between the source and receiver. We also performed analysis on wavefield simulations from physic-based explosion source modeling. The analyses show scattering and phase conversion from 3D heterogonies dominate the generation of far-field, S-wave energy observed in data, and that the variability in the recovered deviatoric component of the moment tensor source model are largely a result of inadequately accounting for 3D wave propagation effects in the inversion process.

58 GEOSCIENCES↗
DOE OSTI2019

Eulerian Applications Project - xRage: High Explosives Package [Slides]

At the most elementary level, the high explosive model in xRage (or many other hydro codes) computes the amount of material that changes from a high explosive reactant to a high explosive product during a time step and accounts for the energy added to the flow by this reaction. The actual chemical reactions that occur during this conversion are not modeled. These processes are very complicated and involve levels of spatial and temporal resolution that are generally not practical for an application code. They would also require a state variable representation that includes all of the chemical species that are produced by the reaction and account for multiple stage chemical reactions. Instead the explosive models we generally use are phenomenological and try to represent the most important physics that drive the explosive wave in a very simplified way. These models generally have a number of tunable parameters that must be calibrated to experiment.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2021

Large Surface Explosion Coupling Experiment - SNL Remote Optical.

Two surface chemical explosive tests were observed for the Large Surface Explosion Coupling Experiment (LSECE) at the Nevada National Security Site in October 2020. The tests consisted of two one-ton explosions, one occurring before dawn and one occurring mid- afternoon. LSECE was performed in the same location as previous underground tests and aimed to explore the relationship between surface and underground explosions in support of global nonproliferation efforts. Several pieces of remote sensing equipment were deployed from a trailer 2.02 km from ground zero including high-speed cameras, radiometers and a spectrometer. The data collected from these tests will increase the knowledge of large surface chemical explosive signatures.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗