PLS partners with Weapons and Complex Integration (WCI) to work on energetic materials problems
LLNL conducts much of its explosives work at the High Explosives Applications Facility (HEAF). HEAF houses unique facilities for the synthesis, characterization, and testing of high explosives and other energetic materials. HEAF is also equipped with extensive, high-fidelity, high-speed diagnostic capabilities, including x-ray radiography, high-speed photography, laser velocimetry, and embedded particle velocity/pressure measurements.
|HEAF is a 10,000 m2 facility completed in 1990 that includes 4000 m2 of laboratory space and 1200 m2 of office space. Major experimental facilities include a 10-kg, firing tank, two 1-kg firing tanks, and a 10-kg gun tank.|
Solving Problems of National Importance
|HEAF scientists setting up the HYDRA x-ray system used to take a sequence of high-resolution x-ray pictures of an explosively driven experiment in the 10-kg spherical tank shown in the background.|
HEAF is a resource for research, development, and testing in support of stockpile stewardship, conventional defense, and other national needs. HEAF activities support the core stockpile stewardship campaign, the enhanced surveillance campaign, the reliable replacement warhead, the DOE-DoD Joint Munitions Program, and other defense-related projects. Facilities at HEAF include:
- Firing tanks—One 10-kg and two 1-kg firing tanks
are used to characterize the detonation and thermal ignition of explosives
assemblies in support of DOE and DoD programs. These tanks provide a way
to conduct explosive experiments indoors under well-controlled conditions
with complete dynamic diagnostics. Many types of tests are executed in these
tanks, including cylinder test for detonation performance, blast tests for
enhanced blast explosives, and the scaled thermal explosion (STEX) test to
characterize the violence of thermal explosions.
|At HEAF, chemists, physicists, and engineers work side-by-side to synthesize and formulate new explosives with improved performance and safety characteristics.|
- Gun tank—A 100-mm-diam propellant-driven gun fires
projectiles at 300 m/s to 2.5 km/s into a tank capable of holding 3-5 kg
of explosive. The
explosive targets typically have embedded pressure gages to study the one-dimensional
- Microdetonics laboratory—These facilities include
100-gram, 2-gram, and 3-gram firing tanks and are used to study the detonation
of small-scale devices to develop a basic understanding of the functioning
and aging of existing detonators and new detonator concepts.
- Femtosecond Machining Center—This first-of-a-kind
facility is used to cut high-explosive pieces and assemblies using short
laser pulses that vaporize the explosive without thermally heating or damaging
the material left behind. This enables us to examine cut-back,
partial assemblies that are representative of the full devices and fabrication
of very small sticks of high explosive for characterizing detonation behavior.
|These explosive parts were fabricated to a high level of precision using HEAF's first-of-a-kind femtosecond laser facility.|
- Stockpile Detonator Surveillance Facility—A 150-gram firing tank
and an inspection laboratory is used to monitor the performance of stockpile-return
- Synthesis and formulation laboratories—New energetic
compounds for DOE and DOD weapon applications are synthesized from the milligram
to multikilogram scale in HEAF and at the Site 300 scale-up facility. Our
efforts in the past years concentrated on the synthesis of new insensitive
energetic compounds such as LLM-105 and the development of a new method for
the synthesis of TATB.
- Pressing laboratories—A pressing laboratory in HEAF provides small-scale
explosive samples for testing, while samples that are larger or that require
machining are provided by the PLS Site 300 Facility.
- Material characterization laboratories—A variety of thermal analysis and small-scale safety tests characterize energetic materials for handling safety, thermal stability, compatibility, and lifetime characteristics. Equipment includes differential scanning calorimetry, thermal expansion, thermal conductivity, porosity, permeability, high-pressure strand burner, one-dimensional time to explosion (ODTX) apparatus, SEM, particle size measurement, and spark, friction, and drop-hammer tests.
The microdetonics laboratory is used to study the detonation of small-scale devices to develop a basic understanding of the functioning and aging of existing detonators and new detonator concepts.
The combination of cutting-edge computational analysis and highly diagnosed experiments will provide advances in energetic materials research. We are focusing on four major categories: performance, safety, reliability/surveillance, and new materials. The new diagnostic tools we use to observe the propagation of a detonation wave will enable the development of improved tools to analyze the performance of existing and new materials. These tools will also help us to develop more effective applications of insensitive explosives in the stockpile and in conventional weapons. Similarly, this approach will lead to the ability to evaluate the response of energetic materials to a wide variety of stimuli, providing a scientific basis for resolving safety questions and improving designs with respect to safety.
We continue to focus on detailed understanding of the aging effects in energetic materials, with the goal of identifying potential age-related changes and extending the projected lifetime of energetic materials. Finally, we are developing novel energetic molecules, formulations, and nanoenergetics to support improved safety and performance in the nuclear weapons stockpile as well as the trend toward small, high-value weapon systems that require innovative materials.