"Fat Man" is the codename for the type of nuclear bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation marked the third nuclear explosion in history. It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site, and it was dropped from the Boeing B-29 Superfortress Bockscar piloted by Major Charles Sweeney.
"Little Boy" was the codename for the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II. It was the first nuclear weapon used in warfare. The bomb was dropped by the Boeing B-29 Superfortress Enola Gay piloted by Colonel Paul W. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces and Captain Robert A. Lewis. It exploded with an energy of approximately 15 kilotons of TNT (63 TJ) and caused widespread death and destruction throughout the city. The Hiroshima bombing was the second man-made nuclear explosion in history, after the Trinity nuclear test.
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion reactions, producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter.
Operation Smiling Buddha was the assigned code name of India's first successful nuclear bomb test on 18 May 1974. The bomb was detonated on the army base Pokhran Test Range (PTR), in Rajasthan, by the Indian Army under the supervision of several key Indian generals.
A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven projectiles, pressure damage, and explosion-generated effects. Bombs have been utilized since the 11th century starting in East Asia.
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types:
Classified information is material that a government body deems to be sensitive information that must be protected. Access is restricted by law or regulation to particular groups of people with the necessary security clearance and need to know, and mishandling of the material can incur criminal penalties.
Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions. However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.
Operation Castle was a United States series of high-yield (high-energy) nuclear tests by Joint Task Force 7 (JTF-7) at Bikini Atoll beginning in March 1954. It followed Operation Upshot–Knothole and preceded Operation Teapot.
Ivy King was the largest pure-fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy. This series of tests involved the development of very powerful nuclear weapons in response to the nuclear weapons program of the Soviet Union.
Since their public debut in August 1945, nuclear weapons and their potential effects have been a recurring motif in popular culture, to the extent that the decades of the Cold War are often referred to as the "atomic age".
A thermonuclear weapon, fusion weapon or hydrogen bomb is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation atomic bombs, a more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material such as uranium-235 or plutonium-239. The first full-scale thermonuclear test was carried out by the United States in 1952; the concept has since been employed by most of the world's nuclear powers in the design of their weapons.
"Born secret" and "born classified" are both terms which refer to a policy of information being classified from the moment of its inception, usually regardless of where it was created, and usually in reference to specific laws in the United States that are related to information that describes the operation of nuclear weapons.
The United States government classification system is established under Executive Order 13526, the latest in a long series of executive orders on the topic beginning in 1951. Issued by President Barack Obama in 2009, Executive Order 13526 replaced earlier executive orders on the topic and modified the regulations codified to 32 C.F.R. 2001. It lays out the system of classification, declassification, and handling of national security information generated by the U.S. government and its employees and contractors, as well as information received from other governments.
Q clearance or Q access authorization is the U.S. Department of Energy (DOE) security clearance required to access Top Secret Restricted Data, Formerly Restricted Data, and National Security Information, as well as Secret Restricted Data. Restricted Data (RD) is defined in the Atomic Energy Act of 1954 and covers nuclear weapons and related materials. The lower-level L clearance is sufficient for access to Secret Formerly Restricted Data (FRD) and National Security Information, as well as Confidential Restricted Data, Formerly Restricted Data, and National Security Information. Access to Restricted Data is only granted on a need-to-know basis to personnel with appropriate clearances.
Restricted Data (RD) is a category of proscribed information, per National Industrial Security Program Operating Manual (NISPOM). Specifically, it is defined by the Atomic Energy Act of 1954 as:
A strong link/weak link and exclusion zone nuclear detonation mechanism is a type of safety mechanism employed in the arming and firing mechanisms of modern nuclear weapons.
Muhammad Hafeez Qureshi, SI, HI, known as Hafeez Qureshi, was a Pakistani nuclear scientist and a mechanical engineer, known for his classified work at WGS at the Pakistan Atomic Energy Commission (PAEC).
Nuclear Non-Proliferation Act of 1978, 22 U.S.C. § 3201, is a United States federal law declaring that nuclear explosive devices pose a perilous threat to the security interests of the United States and continued international progress towards world peace and the development of nations.