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A study of diverging detonation in high-explosive systems. [Detonation in PBX-9502 main charge with two different booster materials; TATB and X-0407]

Description: Initiation of an insensitive high-explosive main charge can be achieved by using a booster. The requirement for the booster high explosive should be high sensitivity rather than high energy. Using a reactive model, this study presents the evolution of detonation in PBX-9502 main charge with two different booster materials: low-density ultrafine TATB and X-0407 in a diverging configuration. 7 refs., 3 figs.
Date: January 1, 1987
Creator: Tang, P.K.
Partner: UNT Libraries Government Documents Department

Evaluation of Kraton GX-6500 as a binder material

Description: A 23-kilogram batch of a 95 percent HMX/5 percent Kraton GX-6500 PBX formulation has been made and subjected to routine safety evaluation and preliminary physical properties screening. No unusual reactivity was seen; drop hammer sensitivity is similar to LX-10. Diametric disc test parts, pressed to about 98 percent of TMD at 281 MPa/120 C, indicate that the PBX strength lies between LX-04-1 and LX-09.
Date: September 1, 1977
Creator: Johnson, H.D.; Osborn, A.G.; Stallings, T.L. & Anthony, J.R.
Partner: UNT Libraries Government Documents Department

Characterization of explosives by observing growth to detonation using a fiber optics system

Description: A system has been developed to observe the growth to detonation of high explosives using fiber optics to monitor light emission at the detonation front. The corresponding voltage waveform is digitized and fed to a computer for peak location and data analysis. Measurements close to the initiation point reveal an acceleration zone in which the velocity for growth to final detonation occurs. The characteristics of this acceleration region are related to the physical properties and sensitivity of the test explosive.
Date: unknown
Creator: Mohler, J.H. & Moodie, W.J.
Partner: UNT Libraries Government Documents Department

Acetone/hexane recrystallization of HNAB

Description: In the manufacturing process for hexanitroazobenzene (HNAB), the final step prior to heat treatment is a recrystallization of HNAB from an acetonitrile/tetrachlorethane mixture. The possibility that the above solvents might become unavailable at some future date and the toxicities of these solvents indicate a need for a new solvent system. Initial work using acetone/hexane in place of acetonitrite/tetrachloroethane indicated its feasibility (D. M. O'Keefe, Sandia Laboratories, Private Communication). The objective of the present work was to confirm the feasibility of the use of acetone/hexane system and then to scale-up the recrystallization to the size and type of equipment used in the manufacturing process. A 7.2 kg batch of HNAB was produced with the final recrystallization from the acetone/hexane system. The analysis of the HNAB-II compared favorably with that from the production process. A 50 g sample was furnished to Sandia Laboratory.
Date: August 1, 1977
Creator: Quinlin, W.T. & Evans, V.H.
Partner: UNT Libraries Government Documents Department

Sensitivity testing and analysis

Description: New methods of sensitivity testing and analysis are proposed. The new test method utilizes Maximum Likelihood Estimates to pick the next test level in order to maximize knowledge of both the mean, {mu}, and the standard deviation, {sigma} of the population. Simulation results demonstrate that this new test provides better estimators (less bias and smaller variance) of both {mu} and {sigma} than the other commonly used tests (Probit, Bruceton, Robbins-Monro, Langlie). A new method of analyzing sensitivity tests is also proposed. It uses the Likelihood Ratio Test to compute regions of arbitrary confidence. It can calculate confidence regions, for {mu}, {sigma}, and arbitrary percentiles. Unlike presently used methods, such as the program ASENT which is based on the Cramer-Rao theorem, it can analyze the results of all sensitivity tests, and it does not significantly underestimate the size of the confidence regions. The new test and analysis methods will be explained and compared to the presently used methods. 19 refs., 12 figs.
Date: January 1, 1991
Creator: Neyer, B.T.
Partner: UNT Libraries Government Documents Department

Formulation of custom sized LX-15 granules

Description: LX-15 is a booster explosive formulation consisting of 95% HNS I and 5% Kel F-800 developed by Lawrence Livermore Laboratory. The purpose of this effort was to develop formulation techniques for the production of custom size granules that are amenable for processing in automatic weighing equipment. This report details processes whereby 0.4 and 1.5 kg size batches are produced, meeting those requirements. Efforts to date have found that granule size is dependent on batch/vessel size, water-to-solvent ratio and the degree of vessel agitation.
Date: April 1, 1980
Creator: Stull, T.W.
Partner: UNT Libraries Government Documents Department

Inter- and intra-laboratory sieve analysis of TATB

Description: The purpose of this combined laboratory study was to determine inter- and intra-laboratory repeatability and influence procedure changes have on the sieving of TATB. Procedure changes include the use of different sieve sets, technicians, sieving rate, sample size and disperision. Results of this study indicate inter- as well as intra-laboratory repeatability in sieving is influenced by the use of different sieve sets and dispersion techniques.
Date: August 1, 1977
Creator: Duncan, A.A.
Partner: UNT Libraries Government Documents Department

Development of the MC3133 reefing line cutter

Description: A pyrotechnic actuated reefing line cutter has been developed which, in response to an incoming programmable time delayed electrical firing signal, severs a nylon or Kevlar parachute reefing line following parachute deployment. The design objectives and final design concept which evolved are described. First order approximations and parameter studies leading to a preprototype design are presented. Significant evaluation studies that resulted in the selection of boron/calcium chromate for the initiating charge and titanium subhydride/potassium perchlorate for the output charge are discussed in detail. Final design verification testing data show that the reefing line cutter will meet functional requirements after the following sequential environments: thermal shock, --54/sup 0/C to 90/sup 0/C; mechanical shock, 9806 m/s/sup 2/, 2 ms duration; vibration, 98 m/s/sup 2/, 26-2000 Hz; and linear acceleration, 1960 m/s/sup 2/ for two minutes.
Date: September 1, 1977
Creator: Craig, J.R.
Partner: UNT Libraries Government Documents Department

Mechanical properties of TATB/Kel-F 800 formulation. Period covered: October--December 1975

Description: The effects of controlled crosshead velocity or strain-rate application on the compression and tensile test results for LLL B8 TATB PBX appeared to be statistically insignificant. Bartherm treatment of billets resulted in a decrease in tensile strength. The thermal growth of the dimensional test specimen thermal cycled under a constant load of 1.72 MPa in L45 silicone oil was 50% less than the control specimen growth.
Date: January 1, 1975
Creator: Johnson, H.D.
Partner: UNT Libraries Government Documents Department

Compositional analysis technique for HNS/Kel-F 800

Description: A compositional analysis procedure for the plastic-bonded explosive consisting of HNS and Kel-F 800 is presented. The Kel-F is determined gravimetrically after extraction of the HNS with fuming nitric acid. The HNS content is calculated by difference.
Date: August 1, 1980
Creator: Sandoval, J.
Partner: UNT Libraries Government Documents Department

Decomposition of energetic materials on the drop-weight impact machine

Description: The drop-weight impact test is essential for initial characterization of limited amounts of new energetic materials. The mechanisms for reaction of energetic materials on the drop-weight machine are largely unknown. Partly as a consequence of this lack of understanding, results obtained on the drop-weight machine are often misleading and inconsistent. We are investigating mechanisms for decomposition of explosives on the drop-weight machine using radiometric and spectroscopic methods. Initial radiometric results reveal consistent, sequential emissions for specific impacted explosives that probably correspond to time-resolved chemical reactions. Time-resolved C/sub 2/* emission has been tentatively identified using spectroscopic methods to examine impacted explosives. 11 refs., 9 figs.
Date: January 1, 1988
Creator: Buntain, G.A.; McKinney, T.; Rivera, T. & Taylor, G.
Partner: UNT Libraries Government Documents Department

Thermochemistry of mixed explosives

Description: In order to predict thermal hazards of high-energy materials, accurate kinetics constants must be determined. Predictions of thermal hazards for mixtures of high-energy materials require measurements on the mixtures, because interactions among components are common. A differential-scanning calorimeter (DSC) can be used to observe rate processes directly, and isothermal methods enable detection of mechanism changes. Rate-controlling processes will change as components of a mixture are depleted, and the correct depletion function must be identified for each specific stage of a complex process. A method for kinetics measurements on mixed explosives can be demonstrated with Composition B is an approximately 60/40 mixture of RDX and TNT, and is an important military explosive. Kinetics results indicate that the mator process is the decomposition of RDX in solution in TNT with a perturbation caused by interaction between the two components. It is concluded that a combination of chemical kinetics and experimental self-heating procedures provides a good approach to the production of predictive models for thermal hazards of high-energy materials. Systems involving more than one energy-contributing component can be studied. Invalid and dangerous predictive models can be detected by a failure of agreement between prediction and experiment at a specific size, shape, and density. Rates of thermal decomposition for Composition B appear to be modeled adequately for critical-temperature predictions with the following kinetics constants: E = 180.2 kJ mole/sup -1/ and Z = 4.62 X 10/sup 16/ s/sup -1/.
Date: January 1, 1982
Creator: Janney, J.L. & Rogers, R.N.
Partner: UNT Libraries Government Documents Department

Electrostatic sensitivity testing of explosives at Los Alamos

Description: An electrostatic sensitivity test for determining the handling hazards associated with both new and established explosives has been developed at Los Alamos and is now in routine use. The apparatus is a moving electrode device similar to that described by Kusler and Brown. The energy stored in selected capacitors of a capacitor bank is discharged through the sample of explosive. A unique system of confining the samples with lead foil allows one to measure various degrees of sample response to changes in the electrostatic stimulus. Varying the foil thickness provides information about both the ''sensitiveness'' and the ''explosiveness'' of the sample. The lead-foil-confinement technique eliminates the subjective description of the response of a secondary explosive to a marginal stimulus as is common in many explosives tests on secondaries. Variables studied included: particle size, sample weight, electrode material, series resistance, temperature, voltage, sample volume, and degree of confinement. 6 refs., 2 figs., 6 tabs.
Date: January 1, 1989
Creator: Larson, T.E.; Dimas, P. & Hannaford, C.E.
Partner: UNT Libraries Government Documents Department

Arming and firing system for DISTANT RUNNER

Description: Sandia A and F systems Division 1132 provided arming and firing support for the DISTANT RUNNER Test Program at White Sands Missile Range. This report describes the field support and the firing system that was used.
Date: March 1, 1982
Creator: Skenandore, L.H. & Johnson, J.P.
Partner: UNT Libraries Government Documents Department

Calibration curves for some standard Gap Tests

Description: The relative shock sensitivities of explosive compositions are commonly assessed using a family of experiments that can be described by the generic term ''Gap Test.'' Gap tests include a donor charge, a test sample, and a spacer, or gap, between two explosives charges. The donor charge, gap material, and test dimensions are held constant within each different version of the gap test. The thickness of the gap is then varied to find the value at which 50% of the test samples will detonate. The gap tests measure the ease with a high-order detonation can be established in the test explosive, or the ''detonability,'' of the explosive. Test results are best reported in terms of the gap thickness at the 50% point. It is also useful to define the shock pressure transmitted into the test sample at the detonation threshold. This requires calibrating the gap test in terms of shock pressure in the gap as a function of the gap thickness. It also requires a knowledge of the shock Hugoniot of the sample explosive. We used the 2DE reactive hydrodynamic code with Forest Fire burn rates for the donor explosives to calculate calibration curves for several gap tests. The model calculations give pressure and particle velocity on the centerline of the experimental set-up and provide information about the curvature and pulse width of the shock wave. 10 refs., 1 fig.
Date: January 1, 1989
Creator: Bowman, A.L. & Sommer, S.C.
Partner: UNT Libraries Government Documents Department

Modeling heterogeneous high explosive burn with an explicit hot-spot process

Description: We present a method of treating high explosive burn with a multi-step process which includes the hot-spot excitation, decomposition, and the propagation of reaction into the region outside the hot spots. The basic features of this model are the separation of the thermal-mechanical and chemical processes, and the partition of the explosive into hot spots and the region exclusive of the hot spots. The thermal-mechanical aspects are formulated in a way similar to the chemical process. The combined processes lead to a set of rate equations for the mass fractions of reactants, intermediate states, and final products. The rates are expressed initially in terms of general characteristic times, but with specific phenomenological correlations introduced in the final model. Computational examples are given of simulated flyer plate impacts, short-shock initiation, corner turning, and shock desensitization. 19 refs., 9 figs.
Date: January 1, 1985
Creator: Tang, P.K.; Johnson, J.N. & Forest, C.A.
Partner: UNT Libraries Government Documents Department

Flowing afterglow spectroscopy: an ultrasensitive probe into solid-phase decomposition kinetics

Description: The thermal-decomposition kinetics of high explosives are important to manufacturers and handlers of these dangerous materials from the standpoint of processing and storage. Two broad temperature regions are of particular importance, i.e., the high (greater than or equal to 200/sup 0/C) temperature region associated with fire hazard and the low (approx. 20 to 200/sup 0/C) region associated with storage and processing environments. The paper describes the technique in detail and summarizes recent efforts to elucidate the low-temperature kinetics of trinitrotriaminobenzene (TATB) and nitroguanidine (NQ).
Date: January 1, 1979
Creator: Taylor, G.W. & Andrews, G.H. Jr.
Partner: UNT Libraries Government Documents Department

Excess transit time as a function of burst current in an exploding bridgewire detonator

Description: Transit time, the time from bridgewire burst until breakout of detonation from the output pellet of an exploding bridgewire detonator, was measured as a function of burst current. From this data, in conjunction with known equations for run distance versus pressure, unreacted explosive Hugoniots, and detonation properties of the initial pressing pellet, the run distance in the initial pressing explosive pellet and shock pressure from the exploding bridgewire were determined, both as a function of burst current.
Date: January 1, 1990
Creator: Cooper, P.W.; Owenby, R.N. & Stofleth, J.H.
Partner: UNT Libraries Government Documents Department