A5016420457- Energetic Materials and Combustion
- Atmospheric chemistry and aerosols
- Thermal and Kinetic Analysis
- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- Air Quality Monitoring and Forecasting
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Indoor Air Quality and Microbial Exposure
- Mass Spectrometry Techniques and Applications
- Toxic Organic Pollutants Impact
- Chemical Thermodynamics and Molecular Structure
- Bacillus and Francisella bacterial research
- Advanced Chemical Sensor Technologies
- Air Quality and Health Impacts
- Combustion and Detonation Processes
- Atomic and Molecular Physics
- Medical Imaging Techniques and Applications
- Nuclear Physics and Applications
- Inhalation and Respiratory Drug Delivery
- Fusion materials and technologies
- Boron and Carbon Nanomaterials Research
- Meteorological Phenomena and Simulations
- European and Russian Geopolitical Military Strategies
- Advanced X-ray and CT Imaging
Lawrence Livermore National Laboratory
2008-2024
Lawrence Livermore National Security
2012
Applied Energetics (United States)
2012
Sandia National Laboratories
2012
General Atomics (United States)
2012
University of California, San Diego
2011
Michigan State University
2008
University of Augsburg
2006
University of California, Riverside
2000-2003
University of California, Davis
2003
Capsule implosions on the National Ignition Facility (NIF) [Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with goal of compressing deuterium-tritium (DT) fuel to a sufficiently high areal density (ρR) sustain self-propagating burn wave required for fusion power gain greater than unity. These driven carefully tailored sequence four shock waves that must be timed very precision in order keep DT low adiabat. Initial experiments measure strength and relative timing these shocks have...
The rapid chemical analysis of individual cells is an analytical capability that will profoundly impact many fields including bioaerosol detection for biodefense and cellular diagnostics clinical medicine. This article describes a mass spectrometry-based technique the real-time reagentless characterization airborne without sample preparation. We characterize spectral signature Bacillus spores demonstrate ability to distinguish two spore species, B. thuringiensis atrophaeus, from one another...
Ignition implosions on the National Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with goal of compressing deuterium-tritium fuel to a sufficiently high areal density (ρR) sustain self-propagating burn wave required for fusion power gain greater than unity. These driven very carefully tailored sequence four shock waves that must be timed precision keep entropy and adiabat low ρR high. The first series tuning experiments Facility, which use optical diagnostics...
[1] Oceans represent a significant natural source of gases and particles to the atmosphere. Relative gas phase compounds, less is known regarding influence changes in biological activity ocean on chemistry sea spray aerosols produced marine environments. To gain insight into biology atmospheric aerosol chemistry, simultaneous real-time measurements were made size chemical mixing-state, dimethyl sulfide (DMS), as well seawater DMS chlorophyll a. In three different environments with elevated...
A major objective of the Indian Ocean Experiment (INDOEX) involves characterization extent and chemical composition pollution outflow from Subcontinent during winter monsoon. During this season, low‐level flow continent transports pollutants over toward Intertropical Convergence Zone (ITCZ). Traditional standardized aerosol particle analysis, together with real‐time single fast‐response gas‐phase measurements provided sampled properties. The gas‐ particle‐phase compositions encountered air...
During the Indian Ocean Experiment Intensive Field Phase 99, aerosol time‐of‐flight mass spectrometry (ATOFMS) was used for on‐line characterization of size and chemical composition individual particles. High temporal resolution single‐particle measurements were made on Island Kaashidhoo board Research Vessel Ronald H. Brown during February March, respectively. Sea‐salt dust particles are major contributors to between 1.0 2.5 μm. For with aerodynamic diameters 0.2 μm, carbon‐containing...
Predicting the cloud condensation nuclei (CCN) supersaturation spectrum from aerosol properties is a fairly straightforward matter, as long those are simple. During Indian Ocean Experiment we measured CCN spectra, size‐resolved chemical composition, and number distributions attempted to reconcile them using modified form of Köhler theory. We obtained general agreement between our modeled spectra. However, was not good during time period when organic carbon comprised quarter total mass in...
Different particulate matter (PM) samples were investigated by on-line single-particle aerosol time-of-flight mass spectrometry (ATOFMS). The consist of soot particulates made a diffusion flame generator (combustion standard, CAST), industrially produced material (printex), from diesel passenger car as well ambient (urban dust (NIST) and road tunnel dust). Five different CAST particle generated with elemental carbon (EC) organic (OC) content. reaerosolized analyzed ATOFMS, precipitated on...
A cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) chamber. This instrument incorporates ability to fill, form, characterize NIF targets with hydrogen isotopes needed for ignition experiments inside bay then transport position them in effort brought fruition years of research growing metrologizing high-quality fuel layers landed it an especially demanding operations environment facility. D-T (deuterium-tritium) have extremely tight...
Abstract Understanding the molecular composition of high explosives during thermal decomposition is vital for predicting sensitivity, safety, and performance explosive materials. The 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) has been linked to formation furazans through a series dehydration reactions NO 2 NH groups on phenyl ring, along with breakdown into small molecules (≤120 amu). Molecular identification compounds formed in this transformation light gases lacking. To address this, we...
First synthesized in 1888 as a dye, TATB (1,3,5-triamino-2,4,6-trinitrobenzene) was not recognized high explosive until 1956 when it reported that possesses combination of performance properties, thermal stability, and low impact sensitivity 1. Now, decades later, is widely regarded the most established insensitive explosive. However, despite having been used, decomposition kinetics remain elusive. Thermal literature disagrees on importance identity intermediate species, both gas solid...
Bioaerosol mass spectrometry (BAMS) performs single-cell analysis in real time. However, the specificity of BAMS signatures has been limited by low sensitivity at high masses. To increase range and BAMS, a novel design was developed that utilizes linear flight tube with delayed extraction an electrostatic ion guide. This study quantifies limits evaluates feasibility to detect higher biomarkers from single cells. All experiments were carried out using MALDI aerosol particles nebulized...
Actual or surrogate chemical, biological, radiological, nuclear, and explosive materials illicit drug precursors can be rapidly detected identified when in aerosol form by a Single-Particle Aerosol Mass Spectrometry (SPAMS) system. This entails not only the sampling of such particles but also physical analysis subsequent data leading to highly reliable alarm state. SPAMS hardware is briefly reviewed. software algorithms are discussed greater detail. A laboratory experiment involving actual...
Bioearosol mass spectrometry (BAMS) analyzes single particles in real time from ambient air, placing strict demands on instrument sensitivity. Modeling of the BAMS reflectron flight (TOF) with SIMION revealed design limitations associated ion transmission and sensitivity at higher masses. Design implementation a linear TOF electrostatic guide delayed extraction capabilities has greatly increased range relative to design. Initial experimental assessment new improved high masses as illustrated...
Abstract Accurate quantitation of 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) is important because its strategic use as an energetic material. A purity determination also needed for the proper assessment performance. fast and sensitive method has been developed to measure TATB in polymer‐bonded materials. The target material extracted with DMSO, extract separated on a reversed‐phase chromatography column. column effluent monitored by diode array detection (DAD) at 354 nm. characteristic...
Abstract Understanding the thermal decomposition behavior of TATB (1,3,5-triamino-2,4,6-trinitrobenzene) is a major focus in energetic materials research because safety issues. Previous and modelling efforts have suggested benzo-monofurazan condensation producing H 2 O initiating step. However, early evolving CO (m/z 44) along with 18) evolution been observed by mass spectrometric monitoring head-space gases both constant heating rate isothermal studies. The source has not explained, until...
Abstract TATB (1,3,5‐triamino‐2,4,6‐trinitrobenzene) was thermally degraded by two small‐scale analytical methods – simultaneous differential scanning calorimetry and thermogravimetric analysis (SDT) a hot‐stage microscope with Fourier Transform Infrared (FTIR) capabilities. SDT used ramped heating, isothermal soaking, thermal pretreatment at various conditions. The heat flow mass loss were monitored during treatment conditions to derive chemical decomposition kinetics Arrhenius parameters....
The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. emission organic material gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that particle chemistry in marine environments. However, direct particle-phase sulfur largely unexplored. Here we present measurements ocean-derived particles containing reduced sulfur, detected as elemental ions (e.g., 32S+, 64S2+), seven different...
LX-17 (92.5 wt. % tri-nitro-tri-amino-benzene (TATB); 7.5 Kel F 800) at 98 theoretical maximum density (TMD) was thermally treated in the small-scale stainless-steel vessel cook-off test (SSVCT) reactor to understand response of explosive abnormal thermal environments. The sample pressed and machined into a cylinder that provided less than 15% void-space reactor. sealed room pressure heated 0.1 °C/min heating rate until opened about 3000 psi due self-generated gas producing black-brown...
Abstract Concerns surround whether insensitive (or any) energetic materials are more dangerous to handle when exposed abnormal thermal environments. This study characterizes the residual material remaining after LX‐17 (92.5 % 1,3,5‐triamino 2,4,6‐trinitro benzene (TATB) and 7.5 Kel‐F) is various environments in a sealed small‐scale vessel cook‐off test reactor (heated at 0.1 100 °C/min until opened 3000 psi (20.7 MPa)). Previous work has shown no additional sensitivity of these residues as...
Abstract Synthesis and characterization of chemical analogues TATB, where specific atoms in the structure have been isotopically substituted, are reported. 15 N, 2 H, 18 O replaced naturally occurring isotope distributions amino and/or nitro attendant sites 13 C has carbon ring structure. A modified wet‐amination method was used to produce analogues, isotopic replacements were performed by selective choice labeled precursors. Four N‐labeled compounds (N positions), two deuterium‐labeled...
Abstract Delineating the chemical composition of TATB (1,3,5‐triamino‐2,4,6‐trinitrobenzene) residues produced from exposure to abnormal thermal environments should lead a better understanding decomposition paths. Identifying and quantifying each compound in thermally residues, monitors which compounds are degrading or forming along route, as well providing input for kinetic models those pathways. Here we report methodology isolating, identifying, where possible, soluble present solid...
Abstract We investigate and model the cook‐off behavior of 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) to understand response explosive systems in abnormal thermal environments. Decomposition has been explored via conventional ODTX (one‐dimensional time‐to‐explosion), PODTX (ODTX with pressure‐measurement), PyGC‐MS (pyrolysis gas chromatography mass spectrometry), TGA (thermo‐gravimetric analysis), DSC (differential scanning calorimetry), IR (infrared spectroscopy) experiments under...