As another Lame Cherry exclusive in matter anti matter.
Since the late 1940s, weapons engineers have used hydrodynamic tests and dynamic experiments in conjunction with nuclear tests to study and assess the performance and reliability of nuclear weapons primaries. In these types of experiments, test assemblies that mock the conditions of an actual nuclear weapon are detonated using high explosives. In hydrodynamic testing, non-fissile isotopes, such as uranium-238 and plutonium-242, are subjected to enough pressure and shock that they start to behave like liquids (hence the 'hydro' in hydrodynamic).
The primary contains HE which surrounds a metal pit. When a weapon is detonated a series of steps occur very rapidly in a controlled sequence. First the HE is detonated. After the detonators are triggered, a wave of detonation passes through the main HE charge. The HE burn and the detonation wave can be affected by the type of explosive and its chemistry, the grain size, impurities, manufacturing method, and gaps in the HE assembly, among other things. If the HE does not detonate as designed, the pit may not implode properly but may still blow apart, scattering plutonium metal or other materials
Experimental studies are reported of the ignition of pure uranium. Most of the experiments were performed by placing the metal samples in a flowing oxidizing atmosphere (either air or oxygen) within a furnace whose temperature was increasing at the rate of 10° C/min. The ignition temperature of the sample was determined graphically from the sample temperature-time record as the point of intersection between extensions of the pre-ignition heating rate and the post-ignition self-heating rate. The ignition temperature of 8.5-mm cubes of uranium from three sources (in air and in oxygen) was very close to 600° C; however, characteristic differences in reaction were apparent in the 400–500° C range. Metal in an “as-cast” condition self-heated to a greater extent in the 400–500° C region than did beta-quenched metal. Nitrogen-oxygen mixtures also increased selfheating in this region to a greater extent than did helium-oxygen mixtures. Ignition in air or oxygen was followed by spontaneous thermocycling. Peak burning temperatures in air were limited to about 1500° C, but in pure oxygen temperatures greater than 2150° C were recorded.
Thermal stability and spontaneous ignition conditions of uranium hydride and uranium metal fine powders have been studied and observed in an original and dedicated experimental device placed inside a glove box under flowing pure argon. Pure uranium hydride powder with low amount of oxide (<0 .5="" ar="" at="" by="" flowing="" heat="" in="" low="" nbsp="" obtained="" sub="" temperature="" treatment="" was="" wt.="">20>
. Pure uranium powder was obtained by dehydration in flowing pure argon. Those fine powders showed spontaneous ignition at room temperature in air.
Two test devices were exploded in 1953 as part Operation Upshot-Knothole. The aim of the UCRL design was to produce an explosion powerful enough to ignite a thermonuclear weapon, with the minimal amount of fissile material. The core consisted of uranium hydride, with hydrogen, or in the case of Ray, deuterium acting as the neutron moderator. The predicted yield was 1.5 to 3 ktTNT for Ruth and 0.5–1 ktTNT for Ray. The bombs failed to have the predicted explosive power in practice.
- White phosphorus, the original "phosphor"
- Alkali metals (lithium, sodium, potassium, rubidium, caesium), including the alloy NaK
- Finely divided metals (iron, aluminium, magnesium, calcium, zirconium, uranium, titanium, bismuth, hafnium, thorium, osmium, neodymium)
- Some metals and alloys in bulk form (cerium, plutonium)
- Alkylated metal alkoxides or nonmetal halides (diethylethoxyaluminium, dichloro(methyl)silane)
- Potassium graphite (KC8)
- Metal hydrides (sodium hydride, lithium aluminium hydride, uranium trihydride)
- Methane tellurol (CH3TeH), an analog of methanol where tellurium replaces oxygen
- Partially or fully alkylated derivatives of metal and nonmetal hydrides (diethylaluminium hydride, trimethylaluminium, triethylaluminium, butyllithium), with a few exceptions (i.e. dimethylmercury and tetraethyllead)
- Copper fuel cell catalysts, e.g., Cu/ZnO/Al2O3
- Grignard reagents (compounds of the form RMgX)
- Used hydrogenation catalysts such as palladium on carbon or Raney nickel (especially hazardous because of the adsorbed hydrogen)
- Iron sulfide: often encountered in oil and gas facilities where corrosion products in steel plant equipment can ignite if exposed to air.
- Lead and carbon powders produced from decomposition of lead citrate
- Uranium is pyrophoric, as shown in the disintegration of depleted uranium penetrator rounds into burning dust upon impact with their targets. In finely divided form it is readily ignitable, and uranium scrap from machining operations is subject to spontaneous ignition. The GBU-39 is an example of a "bunker buster" bomb where uranium is mentioned in the patent as a way to achieve an "incendiary effect" with "pyrophoricity".
- Plutonium: several compounds are pyrophoric, and it causes some of the most serious fires occurring in United States Department of Energy facilities.
- Petroleum hydrocarbon (PHC) sludge.
- Metalorganics of main group metals (e.g. aluminium, gallium, indium, zinc and cadmium etc.)
- Nonmetal hydrides (arsine, phosphine, diborane, germane, silane)
- Metal carbonyls (dicobalt octacarbonyl, nickel carbonyl)
Magnesium is a highly flammable metal, especially when powdered or shaved into thin strips; (it is, however, difficult to ignite in mass or bulk). Flame temperatures of magnesium and magnesium alloys can reach 3,100 °C (3,370 K; 5,610 °F), although flame height above the burning metal is usually less than 300 mm (12 in). Once ignited, it is difficult to extinguish, being able to burn in nitrogen (forming magnesium nitride), carbon dioxide (forming magnesium oxide, and carbon) and water (forming magnesium oxide and hydrogen). This property was used in incendiary weapons used in the firebombing of cities in World War II, the only practical civil defense being to smother a burning flare under dry sand to exclude the atmosphere. Magnesium may also be used as an ignition source for thermite, a mixture of aluminium and iron oxide powder that is otherwise difficult to ignite.