Along with the pit, the whole physics package was also informally nicknamed "Christy['s] Gadget".
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John D. Prestage is an American physicist currently at NASA and an Elected Fellow of the American Physical Society. He pioneered and designed several ion-trap atomic clocks including the physics package for the NASA Deep Space Atomic Clock (DSAC) Technology Demonstration Mission.
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A Gravel Gertie is a type of bunker designed to provide containment during the nuclear weapons assembly process, when the plutonium or highly enriched uranium "pit" is mated with the high explosive components and wired into the electronics (the "physics package") of the warhead.
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13 versions of the B61 have been designed, known as Mod 0 through Mod 12. Of these, nine have entered production. Each shares the same physics package, with different yield options. The newest variant is the Mod 11, deployed in 1997, which is a ground-penetrating bunker busting weapon.
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Red Snow was a British thermonuclear weapon.Yellow Sun MK.2 Enters Service, Atomic Weapons Establishment timeline, September 2007 Its physics package was based on United States' W28 nuclear warhead used in the B28 nuclear bomb and AGM-28 Hound Dog missile, with an explosive yield of approximately 1.8 megaton.
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W53 physics package The W-53 nuclear warhead of the Titan II ICBM used the same physics package as the B53, without the air drop-specific components like the parachute system and crushable structures in the nose and sides needed for lay-down delivery, reducing its mass to about . The Mark-6 re-entry vehicle containing the W53 warhead was about long, in diameter and was mounted atop a spacer which was in diameter at the missile interface (compared to the missile's core diameter of ). With a yield of 9 megatons, it was the highest yield warhead ever deployed on a US missile. About 65 W53 warheads were constructed between December 1962 and December 1963.
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The physics package of the NIST chip-scale atomic clock A chip scale atomic clock (CSAC) is a compact, low-power atomic clock fabricated using techniques of microelectromechanical systems (MEMS) and incorporating a low-power semiconductor laser as the light source. The first CSAC physics package was demonstrated at NIST in 2003, based on an invention made in 2001. The work was funded by the US Department of Defense's Defense Advanced Research Projects Agency (DARPA) with the goal of developing a microchip-sized atomic clock for use in portable equipment. In military equipment it is expected to provide improved location and battlespace situational awareness for dismounted soldiers when the global positioning system is not available, but many civilian applications are also envisioned.
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Towards the end of 1955, consideration was given to using the physics package of the TX-46 aerial bomb as a warhead for the USAF Snark intercontinental cruise missile. Consideration to use one of the Army's Redstone MRBM was also given. The XW-46/Redstone was canceled in favor of the Titan II/W-53 combination in April 1958.
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Missile warheads in the American arsenal are indicated by the letter "W"; for example, the W61 missile warhead would have the same physics package as the B61 gravity bomb described above, but it would have different environmental requirements, and different safety requirements since it would not be crew- tended after launch and remain atop a missile for a great length of time..
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The AN 51 was a French tactical nuclear warhead used on the Pluton short range missile, the Pluton system was retired in 1992–93. The warhead was based upon the MR 50 CTC (charge tactique commune - common tactical warhead) warhead, with the same physics package as used in the AN 52 bomb. It had two yields; 10 and 25 kt.
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Such complexes were not found. While a nuclear penetrator (the "Robust Nuclear Earth Penetrator", or "RNEP") was never built, the U.S. DOE was allotted budget to develop it, and tests were conducted by the U.S. Air Force Research Laboratory. The RNEP was to use the 1.2 megaton B83 physics package. The Bush administration removed its request for funding of the weapon in October 2005.
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The W21 was an hydrogen bomb design for the US military. It would have used the physics package of the TX-21 bomb. The TX-21 was a weaponized version of the "Shrimp" device tested in the Bravo shot of Operation Castle. A TX-21C was tested as the Navajo shot, Operation Redwing. The TX-21, was a scaled-down version of the Runt device (M-17 hydrogen bomb).
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The core was compressed to prompt super-criticality by the implosion generated by the high explosive lens. This design became known as a "Christy Core" or "Christy pit" after physicist Robert F. Christy, who made the solid pit design a reality after it was initially proposed by Edward Teller. Along with the pit, the whole physics package was also informally nicknamed "Christy['s] Gadget". Of the several allotropes of plutonium, the metallurgists preferred the malleable δ (delta) phase.
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Early weapons often had a removable core for safety, known as in flight insertion (IFI) cores, being inserted or assembled by the air crew during flight. They had to meet safety conditions, to prevent accidental detonation or dropping. A variety of types also had to have a fuse to initiate detonation. US nuclear weapons that met these criteria are designated by the letter "B" followed, without a hyphen, by the sequential number of the "physics package" it contains.
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The use of the low- and high-speed explosives again results in a spherical converging detonation wave to compress the physics package. The original Gadget device used in the Trinity test and Fat Man dropped on Nagasaki used Baratol as the low-VoD explosive and Composition B as the fast, but other combinations can be used. "Trinity" gadget. The alternating high and slow explosives (in purple) are the explosive lens which forces the spherical core to compress into prompt criticality.
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Yellow Sun was the first British operational high-yield strategic nuclear weapon. The name refers only to the outer casing; the warhead (or physics package) was known as "Green Grass" in Yellow Sun Mk.1 and "Red Snow" in Yellow Sun Mk.2. Yellow Sun was designed to contain a variety of warheads. The initial plan was that it would carry an alarm-clock-type warhead known as "Green Bamboo", and then replace it with a true thermonuclear warhead known as "Granite".
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The W80 is physically quite small: the physics package itself is about the size of a conventional Mk.81 bomb, in diameter and long, and only slightly heavier at about . Armorers have the ability to select the yield of the resulting explosion in-flight, a capability referred to as variable yield, colloquially referred to as "dial-a-yield". The minimum yield, perhaps using just the boosted fission primary, is around 5 kilotons of TNT; the highest yield is equivalent to around .
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Since there was no indication of Japan surrendering, they decided to proceed with their orders and drop another bomb. Parsons said that Project Alberta would have it ready by 11 August, but Tibbets pointed to weather reports indicating poor flying conditions on that day due to a storm and asked if the bomb could be made ready by 9 August. Parsons agreed to try to do so. Fat Man F31 was assembled on Tinian by Project Alberta personnel, and the physics package was fully assembled and wired.
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The three Rubidium atomic clocks on-board IRNSS-1A failed, with the first failure occurring in July 2016. ISRO planned to replace it with IRNSS-1H, in August 2017, but this failed to separate from the launch vehicle, but on 12 April 2018, ISRO launched successfully IRNSS-1I as a replacement for IRNSS-1A. The cause of failure was traced to one of the feed through capacitor carrying the DC supply to the physics package of clock, malfunctioning due to excessive rise in temperature.
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Implosion of the pit crushed the neutron generator, mixing the two metals, thereby allowing alpha particles from the polonium to interact with beryllium to produce free neutrons. In modern weapons, the neutron generator is a high-voltage vacuum tube containing a particle accelerator which bombards a deuterium/tritium-metal hydride target with deuterium and tritium ions. The resulting small-scale fusion produces neutrons at a protected location outside the physics package, from which they penetrate the pit. This method allows better control of the timing of chain reaction initiation.
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At the time, the UK's only tactical nuclear weapon was Red Beard, a relatively large weapon of weight. While work continued on Cleo, it was decided to adapt it as a weapon of its own to replace Red Beard, as the 'Improved Kiloton Weapon'. The adapted version of the primary, now the only part of the physics package, became 'Katie'. Katie would be used in a new bomb casing to produce WE.177A, replacing Red Beard with a weapon of roughly 1/3 the weight, and much smaller size.
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A fourth test was an operational test. While the physics package of Blue Danube had been tested, there had been no test of the device in its operational form, so one was included in the Operation Buffalo program. The interdepartmental Atomic Trials Executive in London, chaired by Lieutenant General Sir Frederick Morgan, assumed responsibility for both Operation Mosaic and Operation Buffalo, sitting as the Mosaic Executive (Mosex) or Buffalo Executive (Buffalex) as appropriate. Sir William Penney was appointed scientific director for Operation Buffalo, with Roy Pilgrim, the head of Aldermaston's Trials Division, as his deputy.
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Multiple-warhead missiles require both a miniaturised physics package and a lower mass reentry vehicle, both of which are highly advanced technologies. As a result, single warhead missiles are more attractive for nations with less advanced or less productive nuclear technology. The United States first began development of an MRV payload which was first used on the Polaris A-3 SLBM and was first deployed for use in 1964 on the USS Daniel Webster. The Polaris A-3 carried 3 "bomblets" each having an approximate yield of 200 Kt. The Royal Navy also had MRV payloads with the Chevaline upgrade.
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B61 bomb components. The nuclear physics package is contained in the silver cylinder center-left The B61 has been deployed by a variety of U.S. military aircraft. Aircraft cleared for its use have included the FB-111A, B-1 Lancer, B-2 Spirit, B-52 Stratofortress; F-101 Voodoo, F-100 D & F Super Sabre, F-104 Starfighter, F/A-18 Hornet, F-111 Aardvark and F-4 Phantom II fighter bombers; A-4 Skyhawk, A-6 Intruder and A-7 Corsair II attack aircraft; S-3 Viking antisubmarine aircraft, F-15E Strike Eagle and F-16 Falcon; British, German and Italian Panavia Tornado IDS aircraft. USAFE and all NATO dual role aircraft can carry B61s.
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The B83 is one of the weapons considered for use in the "Nuclear Bunker Buster" project, which for a time was known as the Robust Nuclear Earth Penetrator, or RNEP. While most efforts have focused on the smaller B61-11 nuclear bomb, Los Alamos National Laboratory was also analyzing the use of the B83 in this role. The physics package contained within the B83 has been studied for use in asteroid impact avoidance strategies against any seriously threatening near earth asteroids. Six such warheads, configured for the maximum 1.2 Mt yield, would be deployed by maneuvering space vehicles to "knock" an asteroid off course, should it pose a risk to the Earth.
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The W81 went through several design iterations, starting with an enhanced radiation model, then a pure fission model and cancelled in 1986. Characteristics are not known in detail, but the B61 it is derived from has a physics package (bomb core) of about 12 inch diameter with length of 32 inches, weighing around 300 pounds (see the W80, another B61 derived design). Available LASL images show a much shorter weapon, perhaps 12 by 16 to 18 inches, probably the final fission-only W81 concept, corresponding with the size of the B61 fission primary alone. The LASL image clearly shows the warhead taking up most, but not all, of the 13.5 inch SM-2 body diameter.
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The B77 was a nuclear bomb designed in 1974 to match the delivery capabilities of the B-1A bomber. This included the ability to be dropped from supersonic speeds at altitudes of 60,000 feet, or in a laydown delivery at high subsonic speeds at altitudes as low as 100 feet. Meant to replace the Mk 28 and Mk 43 in the strategic role, the program was cancelled in December 1977 due to rising costs and the cancellation of the bomber it had been designed to serve. Many components of the B77 including its already tested physics package (the actual bomb core) were incorporated in the B83 which was developed in its place.
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The new warhead will not be deployed onto Minuteman III, but instead be deployed on Minuteman III's replacement ICBM system Ground Based Strategic Deterrent. It is not clear if the new W87 mod 1 program is a continuation of the previous W87 mod 1 program, or if it uses any of the physics package developed in the previous W87 mod 1 program. Information released by the Department of Energy on the program states that it "has a similar primary design to the W87-0", which could be evidence that it is like the previous W87 mod 1 program in that it has a different or modified secondary to produce a higher yield. The DoE notes that the weapon is based on previously tested nuclear components.
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Initial designs for the Blue Danube warhead were based on research derived from Hurricane, the first British fission device (which was neither designed nor employed as a weapon), tested in 1952. The actual Blue Danube warhead was proof-tested at the Marcoo (surface) and Kite (air-drop) nuclear trials sites in Maralinga, Australia, by a team of Australian, British and Canadian scientists in late 1956. Blue Danube added a ballistically shaped casing to the existing Hurricane physics package, with four flip-out fins to ensure a stable ballistic trajectory from the planned release height of 50,000 ft. It initially used a plutonium core, but all service versions were modified to use a composite plutonium/U-235 core, and a version was also tested with a uranium-only core.
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One submarine is normally undergoing maintenance and the remaining two are in port or on training exercises. Each submarine carries up to sixteen Trident II D-5 missiles, which can each carry up to twelve warheads, for a maximum of 192 warheads per vessel. However, the British government announced in 1998 that each submarine would carry only 48 warheads (halving the limit specified by the previous government), which is an average of three per missile. However one or two missiles per submarine are probably armed with fewer warheads for "sub-strategic" use causing others to be armed with more. The British-designed warheads are thought to be selectable between 0.3 kilotons, 5–10 kt and 100 kt; the yields obtained using either the unboosted primary, the boosted primary, or the entire "physics package".
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Review: 'Project Icarus (1968) As the students were in a position of nothing being known about the density nor spin rate of the asteroid at the time, the team needed to propose a deflection solution that would not be held back by these unknowns. Eventually the team landed upon a conservative mission architecture that would work with 73 days remaining until impact. It consisted of launching a repeated series of the, then in-development, Saturn V rocket vehicle to deliver 6 to 7 somewhat hypothetical 100-megaton nuclear explosive devices which would detonate about "50 to 100 feet" in proximity to the asteroids surface. With the first explosive Saturn-Icarus 1 physics package arriving at the asteroid with 13 days before Earth-impact remaining, the second Saturn-Icarus 2, arriving with 10 days remaining and so on.
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SADM A suitcase nuclear device (also suitcase nuke, suitcase bomb, backpack nuke, mini-nuke, and pocket nuke) is a tactical nuclear weapon that is portable enough that it could use a suitcase as its delivery method. Both the United States and the Soviet Union developed nuclear weapons small enough to be portable in specially-designed backpacks during the 1950s and 1960s.. The maximum yield of the W54 warhead used in the Special Atomic Demolition Munition (pictured) was 1 kt (1000 tonnes of TNT equivalent). This is larger and heavier than the US W48 nuclear shell at 155 mm (6.1 inches) in diameter and 846 mm (33.3 inches) long and weighing 53.5 kg (118 lb), which represents the smallest complete, self-contained physics package to be fielded and had a yield of 72 tonnes of TNT. Nuclear weapons designer Ted Taylor has alleged that a 105 mm (4.1 inch) diameter shell with a mass of 19 kg is theoretically possible.
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Four months later, The New York Times reported that in 1995 a supposed double agent from the People's Republic of China delivered information indicating that China knew these details about the W88 warhead as well, supposedly through espionage (this line of investigation eventually resulted in the abortive trial of Wen Ho Lee). If these stories are true, it would indicate a variation of the Teller-Ulam design which would allow for the miniaturization required for small MIRVed warheads.Howard Morland, "The holocaust bomb: A question of time" (February 2003) The value of an egg-shaped primary lies apparently in the fact that a MIRV warhead is limited by the diameter of the primary—if an egg-shaped primary can be made to work properly, then the MIRV warhead can be made considerably smaller yet still deliver a high-yield explosion—a W88 warhead manages to yield up to 475 kt with a physics package 68.9 in (1.75 m) long, with a maximum diameter of 21.8 in (0.55 m), and by different estimates weighing in a range from 175 to 360 kg. The smaller warhead allows more of them to fit onto a single missile and improves basic flight properties such as speed and range.
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