Saturday, January 16, 2016

NUKES :: Nuclear Weapons

SOURCE :SOURCE :https://en.wikipedia.org/wiki/Nuclear_weapon




                                               PART -  3  of   3

 ****************************************

 CLICK TO READ

 (  A  )  PART ONE of THREE PARTS -

 http://bcvasundhra.blogspot.in/2016/01/nukes-nuclear-weapon.html

(  B  )  PART   TWO  of THREE PARTS -

 http://bcvasundhra.blogspot.in/2016/01/nukes-nuclear-weapons.html


( C )  PART   THREE  of THREE PARTS -

http://bcvasundhra.blogspot.in/2016/01/source-non-weapons-uses-main-article.html

****************************************




                                             


Non-weapons uses



Main article: Peaceful nuclear explosions

Civil engineering and energy production

See also:

 Athabasca oil sands § Project oilsand and Project Gnome


The 1962 Sedan nuclear testformed a crater 100 m (330 ft) deep with a diameter of about 390 m (1,300 ft), as a means of investigating the possibilities of using peaceful nuclear explosions for large-scale earth moving. If this test was conducted in 1965+, when improvements in device design were realized, a "100-fold" reduction in radiation release was considered feasible.[68] The 140 kiloton Soviet Chagan (nuclear test), comparable in yield to the Sedan test of 104 kt, formed Lake Chagan, reportedly used as a watering hole for cattle and human swimming.[69][70][71]
Apart from their use as weapons, nuclear explosives have been tested and used, in a similar manner to chemical high explosives, for various non-military uses. These have included large-scale earth moving, isotope production and the stimulation and the closing-off of the flow of natural gas.
At the peak of the Atomic Age, the United States initiated Operation Plowshare, involving "peaceful nuclear explosions". TheUnited States Atomic Energy Commission chairman announced that the Plowshares project was intended to "highlight the peaceful applications of nuclear explosive devices and thereby create a climate of world opinion that is more favorable to weapons development and tests".[72][need quotation to verify] The Operation Plowshare program included 27 nuclear tests designed towards investigating these non-weapons uses from 1961 through 1973. Due to the inability of the U.S. physicists to reduce the fission fraction of small, approximately 1 kiloton, yield nuclear devices that would have been required for manycivil engineering projects, when long term health and clean-up costs from fission products were included in the cost, there was virtually no economic advantage over conventional explosives, except for potentially the very largest of projects.[73][74]






Map of all proposed routes for a tunnel and/or canal route from theMediterranean Sea to the Qattara Depression.
No route was shorter than 55 kilometers in length. Canal-cutting investigations began with the buggy salvo shot of Operation Crosstie in 1967.
The Qattara Depression Project, as developed by Professor Friedrich Bassler, who during his appointment to the West German ministry of economics in 1968, put forth a plan to create a Saharan lake and hydroelectric power station by blasting a tunnel between the Mediterranean sea and the Qattara Depression in Egypt, an area that lies below sea level. The core problem of the entire project was the water supply to the depression. Calculations by Bassler showed that digging a canal or tunnel would be too expensive, therefore Bassler determined that the use of nuclear explosive devices, to excavate the canal or tunnel, would be the most economical. The Egyptian government declined to pursue the idea.[75]

The Soviet Union conducted a much more exhaustive program than Plowshare, with 239 nuclear tests, between 1965 and 1988. Furthermore, many of the "tests" were considered economic applications, not tests, in the Nuclear Explosions for the National Economy program.[76]


These included one 30 kiloton explosion being used to close the Uzbekistani Urtabulak gas well in 1966 that had been blowing since 1963, and a few months later a 47 kiloton explosive was used to seal a higher pressure blowout at the nearbyPamuk gas field.[77]


The public records for devices that produced the highest proportion of their yield via fusion-only reactions are possibly the Taiga Soviet peaceful nuclear explosions of the 1970s, with 98% of their 15 kiloton explosive yield being derived from fusion reactions, a total fission fraction of 0.3 kilotons in a 15 kt device.[78][79]

The repeated detonation of nuclear devices underground in salt domes, in a somewhat analogous manner to the explosions that power a car internal combustion engine (in that it would be a heat engine) has also been proposed as a means of fusion power, in what is termed PACER.[80] Other investigated uses for peaceful nuclear explosions were underground detonations to stimulate, by a process analogous to fracking, the flow of petroleum and natural gas in tight formations, this was most developed in the Soviet Union, with an increase in the production of many well heads being reported.[77]

Physics


The element einsteiniumwas first discovered, in minute quantities, following the analysis of the fallout from the first thermonuclear atmospheric test.[81]
The discovery and synthesis of new chemical elements by nuclear transmutation, and their production in the necessary quantities to allow the studying of their properties, was carried out in nuclear explosive device testing. For example, the discovery of the short lived einsteinium and fermium, both created under the intense neutron flux environment within thermonuclear explosions, followed the first Teller-Ulam thermonuclear device test – Ivy Mike. The rapid capture of so many neutrons required in the synthesis ofeinsteinium would provide the needed direct experimental confirmation of the so-called r-process, the multiple neutron absorptions needed to explain the cosmic nucleosynthesis (production) of all heavy chemical elements heavier than nickel on the periodic table, in supernova explosions, before beta decay, with the r-process explaining the existence of many stable elements in the universe.[82]

The worldwide presence of new isotopes from atmospheric testing beginning in the 1950s led to the 2008 development of a reliable way to detect art forgeries. Paintings created after that period may contain traces of caesium-137 and strontium-90, isotopes that did not exist in nature before 1945.[83][84] (Fission products were produced in the natural nuclear fission reactor at Oklo about 1.7 billion years ago, but these decayed away before the earliest known human painting.)[85]

Both climatology and particularly aerosol science, a subfield of atmospheric science, were largely created to answer the question of how far and wide fallout would travel. Similar to radioactive tracers used in hydrology and materials testing, fallout and the neutron activation of nitrogen gas served as a radioactive tracer that was used to measure and then help model global circulations in the atmosphere by following the movements of fallout aerosols.[86][87]


After the Van Allen Belts surrounding Earth were published about in 1958, James Van Allen suggested that a nuclear detonation would be one way of probing the magnetic phenomenon, data obtained from the August 1958 Project Argus test shots, a high altitude nuclear explosion investigation, were vital to the early understanding of Earth's magnetosphere.[88][89





An artist's conception of the NASAreference design for the Project Orionspacecraft powered by nuclear pulse propulsion.
Soviet nuclear physicist and Nobel peace prize recipient Andrei Sakharov also proposed the idea that earthquakes could be mitigated and particle accelerators could be made by utilizing nuclear explosions,[90][91] with the latter created by connecting a nuclear explosive device with another of his inventions, the explosively pumped flux compression generator,[92] to accelerate protons to collide with each other to probe their inner workings, an endeavor that is now done at much lower energy levels with non-explosive superconducting magnets in CERN. Sakharov suggested to replace the copper coil in his MK generators by a big superconductor solenoid to magnetically compress and focus underground nuclear explosions into ashaped charge effect. He theorized this could focus 1023 positively charged protons per second on a 1 mm2 surface, then envisaged making two such beams collide in the form of a supercollider.[93]


Underground nuclear explosive data from peaceful nuclear explosion test shots have been used to investigate the composition of Earth's mantle, analogous to the exploration geophysics practice of mineral prospecting with chemical explosives in "deep seismic sounding" reflection seismology.[94][95][96]

Project A119, proposed in the 1960s, which as Apollo scientist Gary Latham explained, would have been the detonating of a "smallish" nuclear device on the Moon in order to facilitate research into its geologic make-up.[97] Analogous in concept to the comparatively low yield explosion created by the water prospecting (LCROSS) Lunar Crater Observation and Sensing Satellite mission, which launched in 2009 and released the "Centaur" kinetic energy impactor, an impactor with a mass of 2,305 kg (5,081 lb), and an impact velocity of about 9,000 km/h (5,600 mph),[98]releasing the kinetic energy equivalent of detonating approximately 2 tons of TNT (8.86 GJ).

Propulsion use

Main article: Nuclear pulse propulsion



A nuclear shaped charge design that was to provide nuclear pulse propulsion to the Project Orion vehicle.


Although likely never achieving orbit due to aerodynamic drag, the first macroscopic object to obtain Earth orbital velocity was a "manhole cover" propelled by the detonation of test shot Pascal-B, before sputnik obtained orbital velocity, and also successfully became the first satellite, in October 1957. The use of a subterranean shaft and nuclear device to propel an object to escape velocity has since been termed a "thunder well".[99]
The direct use of nuclear explosives, by using the impact of propellant plasma from a nuclear shaped charge acting on a pusher plate, has also been seriously studied as a potential propulsion mechanism for space travel (see Project Orion).[citation needed]
Edward Teller, in the United States, proposed the use of a nuclear detonation to power an explosively pumped soft X-ray laser as a component of a ballistic missile defense shield, this would destroy missile components by transferring momentum to the vehicles surface by laser ablation. This ablation process is one of the damage mechanisms of a laser weapon, but it is also the basis of pulsed laser propulsion for spacecraft.[citation needed]
Ground flight testing by Professor Leik Myrabo, using a non-nuclear, conventionally powered pulsed laser test-bed, successfully lifted a lightcraft 72 meters in altitude by a method similar to ablative laser propulsion in 2000.[100]
A powerful solar system based soft X-ray, to ultraviolet, laser system has been calculated to be capable of propelling an interstellar spacecraft, by the light sailprinciple, to 11% of the speed of light.[101] In 1972 it was also calculated that a 1 Terawatt, 1-km diameter x-ray laser with 1 angstrom wavelength impinging on a 1-km diameter sail, could propel a spacecraft to Alpha Centauri in 10 years.[102]



Asteroid impact avoidance


Main article: Asteroid impact avoidance

See also: B83 nuclear bomb



Artist's impression of the impact event that resulted in the Cretaceous–Paleogene extinction event, which killed the Dinosaurs some 65 million years ago. A natural impact with an explosive yield of 100 teratons of TNT(4.2×1023 J).[103] The most powerful man-made explosion, the Tsar Bomba, by comparison had a yield almost 2 million times smaller – 57 megatons of TNT (2.4×1017 J).[104] The 1994Comet Shoemaker–Levy 9 impacts on planet Jupiter, the Tunguska andChelyabinsk asteroid–Earth collisions of 1908 and 2013 respectively, have served as an impetus for the analysis of technologies that could prevent the destruction of human life by impact events.



A proposed means of averting an asteroid impacting with Earth, assuming low lead times between detection and Earth impact, is to detonate one, or a series, of nuclear explosive devices, on, in, or in a stand-off proximity orientation with the asteroid,[105] with the latter method occurring far enough away from the incoming threat to prevent the potential fracturing of the near-Earth object, but still close enough to generate a high thrust laser ablation effect.[106]
A 2007 NASA analysis of impact avoidance strategies using various technologies stated:[107]
Nuclear stand-off explosions are assessed to be 10–100 times more effective than the non-nuclear alternatives analyzed in this study. Other techniques involving the surface or subsurface use of nuclear explosives may be more efficient, but they run an increased risk of fracturing the target near-Earth object. They also carry higher development and operations risks.
Analysis of the uncertainty involved in nuclear device asteroid deflection shows that the ability to protect the planet does not imply the ability to also target the planet, which is the case with all non-nuclear alternatives, such as the controversial gravity tractor technology. A nuclear explosion that changed an asteroid's velocity by 10 m/s (±20%) would be adequate to push it out of an Earth-impacting orbit. However, if the uncertainty of the velocity change is more than a few plus or minus percent, there would be no chance of directing the asteroid to a particular target.[citation needed]
However, if the need arises to use nuclear explosive devices to prevent an asteroid impact event, it may face the legal issue that the United Nations Committee on the Peaceful Uses of Outer Space and the 1996 Comprehensive Nuclear-Test-Ban Treaty ban nuclear weapons in space.[citation needed]

See also





History

More technical details

Popular culture

Proliferation and politics



Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)