Dense inert metal explosive

Dense inert metal explosive (DIME) is a filling for explosive devices, intended to concentrate more power in a smaller volume, and both improve the chance of target destruction while reducing the damage to people and objects outside the intended explosion radius. While its initial uses are military, commercial applications in manufacturing and mining offer promise.

One prototype, developed jointly by the US Air Force Research Laboratory and the Lawrence Livermore National Laboratory. "consists of a low-density, wrapped carbon-fiber/epoxy matrix integrated with a steel nose and base. The low-density composite case can survive penetration into a one-foot hardened concrete wall. Upon detonation, the carbon-fiber warhead case disintegrates into small non-lethal fibers with little or no metallic fragments, thus significantly reducing collateral damage to people and structures. The warhead explosive fill is a dense inert metal explosive containing fine tungsten particles to provide a ballasted payload with sufficient penetration mass. The tungsten displaces energetic material so as to reduce the total energetic used. The net results are higher dynamic energy impulse all within a small lethal footprint."

Deployment
DIME technology is one of the Focused Lethality Munition (FLM) upgrades planned for the U.S. GBU-39 Small Diameter Bomb. Substituting the carbon filament case alone reduced a danger radius to 25 feet, compared to the 2000 feet of a steel-cased bomb.

Israel is reported to have used it in the 2009 Gaza conflict.

Safety concerns
There have been nontechnical medical concerns stated over possible new injury mechanisms, from tungsten-based DIME weapons used by Israel in the 2009 Gaza conflict. They fall into several categories:
 * Trauma induced by powder, with no obvious fragments as might be caused by metal. The reports, however, do not assess whether the powder injuries might be less or more than from fragment injuries. Still, there are concerns that DIME might violate Protocol 1, dealing with non-detectable fragments, of the Convention on Certain Conventional Weapons.
 * Dr. Erik Fosse, a Norwegian physician in Gaza, agreed that the motive for developing the bombs was to replace the use of depleted uranium, Dr Fosse said the cancer risk from tungsten powde was well known. "These patients should be followed up to see if there are any carcinogenic effects," he said.

2005 research on rats, the National Institute of Environmental Health Sciences of the National Institutes of Health, indicated that tungsten fragments caused rhabdomyosarcoma in all exposed rats. atThis was supported by continuing studies, at the Armed Forces Radiobiology Research Institute, which also that tungsten can be carcinogenic;  Its hazard must be balanced against risk reductions in direct mechanical injuries from blast and fragmentation. It is a difficult call to balance immediate death risks to people in the 25 foot lethal area, cancer risks in an area that is larger but not precisely specified, and the 2000 foot blast and radiation range of a steel-cased standard bomb. Whether inhaled tungsten is as a concern as depleted uranium is another issue; the above experiments all involved tungsten that pierced the skin.

Marc Garlasco, senior military analyst at Human Rights Watch commented "While Human Rights Watch is supportive of the US military’s commitment to reducing civilian casualties, collateral damage as they call it, it is unfortunate that these weapons are being developed specifically for use in densely populated areas which may negate the intended effect." Hambling, the Defense Tech reporter, wrote "We dont know whether a Focused Lethality Munition is likely to result in tungsten particles striking anyone outside the lethal area. Nor do we know the possible environmental impact tungsten powder left afterwards. But given that the Focused Lethality munition will be used in situations which are likely to produce media attention and political repercussions, these should be addressed. The aims of the Low Collateral Damage program are worthwhile. But unless the issues around tungsten are resolved we could see a repeat of the depleted uranium story. Instead of decreasing controversy, the new weapon might create even more."