Jump to content

The Librarian

Timeline of a nuclear explosion in pictures

Topic Summary

Created

Last Reply

Replies

Views

The Librarian -
5
1475

Top Posters


Recommended Posts

Timeline of a nuclear explosion in pictures

Pictures from several detonations as examples of an atomic explosions anatomy

main-qimg-fd9ccd5b442f02427fc8671316dab6c3-c.jpeg

 

Photographers and reporters gather near Frenchman Flat to observe the Priscilla nuclear test; June 24, 1957

Nuclear Chemistry Behind the Explosion

Atomic bombs are made up of a fissile element, such as uranium, that is enriched in the isotope that can sustain a fission nuclear chain reaction. When a free neutron hits the nucleus of a fissile atom like uranium-235 (235U), the uranium splits into two smaller atoms called fission fragments, plus more neutrons. Fission can be self-sustaining because it produces more neutrons with the speed required to cause new fissions. This creates the chain reaction.

The uranium-235 content of "weapons-grade" uranium is generally greater than 85 percent, though inefficient weapons, deemed "weapons-usable," can be made of 20 percent enriched uranium. The very first uranium bomb, Little Boy, dropped on Hiroshima in 1945, used 64 kilograms of 80 percent enriched uranium.

In fission weapons, a mass of fissile material, either enriched uranium or plutonium, is assembled into a supercritical mass—the amount of material needed to start an exponentially growing nuclear chain reaction. This is accomplished either by shooting one piece of sub-critical material into another, termed the "gun" method, or by compressing a sub-critical sphere of material using chemical explosives to many times its original density, called the "implosion" method.

The implosion method is considered more sophisticated than the gun method and only can be used if the fissile material is plutonium. The inherent radioactivity of uranium will then release a neutron, which will bombard another atom of 235U to produce the unstable uranium-236, which undergoes fission, releases further neutrons, and continues the process.The uranium atom can split any one of dozens of different ways, as long as the atomic weights add up to 236 (uranium plus the extra neutron). The following equation shows one possible split, namely into strontium-95 (95Sr), xenon-139 (139Xe), and two neutrons (n), plus energy:

The immediate energy release per atom is about 180 million electron volts (Me). Of the energy produced, 93 percent is the kinetic energy of the charged fission fragments flying away from each other, mutually repelled by the positive charge of their protons. This initial kinetic energy imparts an initial speed of about 12,000 kilometers per second.

However, the charged fragments' high electric charge causes many inelastic collisions with nearby nuclei, and thus these fragments remain trapped inside the bomb's uranium pit. Here, their motion is converted into X-ray heat, a process which takes about a millionth of a second. By this time, the material in the core and tamper of the bomb is several meters in diameter and has been converted to plasma at a temperature of tens of millions of degrees. This X-ray energy produces the blast and fire which are normally the purpose of a nuclear explosion.

Source: Boundless. “The Atomic Bomb.” Boundless Chemistry. Boundless, 08 Aug. 2016. Retrieved 10 Nov. 2016 from The Atomic Bomb - Boundless Open Textbook

Detonation: The Actual Time of the Reaction

Neutron travels at speeds of about 10 million meters per second, or about 3% the speed of light. The characteristic time for a generation is roughly the time required to cross the diameter of the sphere of fissionable material.

A critical mass of uranium is about the size of a softball (0.1 meters).

The time the neutron would take to cross the sphere is:

main-qimg-2ddcbca05acaa5fd9c8e3412b0f463

OR

main-qimg-a7770c43fce13080861659769468f2

The complete process of a bomb explosion is about 80 times this number, or slightly less than a microsecond or .0000008 seconds.

The 80 times represents how many fissions generations occurred in the Trinity test bomb but 99.99% of the energy is released in the last 10 generations, in total .00000008 seconds. This time was informally known as a 'shake' ("as fast as the shake of a lamb's tail") by the physicists at Los Alamos.

main-qimg-93879b8692d8b5a4dcb7376da5c55ded-c.jpeg

.00000008 seconds

Immediately after the explosion time, the temperature of the weapon material is several tens of million degrees and the pressures are estimated to be many million atmospheres. As a result of numerous inelastic collisions, part of the kinetic energy of the fission fragments is converted into internal and radiation energy. Some of the electrons are removed entirely from the atoms, thus causing ionization, others are raised to higher energy (or excited) states while still remaining attached to the nuclei. Within an extremely short time, perhaps a hundredth of a microsecond or so, the weapon residues consist essentially of completely and partially stripped (ionized) atoms, many of the latter being in excited states, together with the corresponding free electrons. The system then immediately emits electromagnetic (thermal) radiation, the nature of which is determined by the temperature. Since this is of the order of several times 107 degrees, most of the energy emitted within a microsecond or so is in the soft X-ray region

 
main-qimg-85f0cab14bb7db6ac8937c448217f0
main-qimg-72fc6163b772ba115ec669b6ad713a
main-qimg-39e87cdaf06dfa0f88e6f74af81a55

H (maximum for local fallout)

where H feet is the maximum value of the height of burst for which there will be appreciable local fallout. This expression is plotted above. For an explosion of 1,000 kilotons, i.e., 1 megaton yield, it can be found from the above graph that significant local fallout is probable for heights of burst less than about 2,900 feet. It should be emphasized that the heights of burst estimated in this manner are approximations only, with probable errors of +30 percent. Furthermore, it must not be assumed that if the burst height exceeds the value in the graph there will definitely be no local fallout. The amount, if any, maybe expected, however, to be small enough to be tolerable under emergency conditions.

H (maximum for local fallout)

where H feet is the maximum value of the height of burst for which there will be appreciable local fallout. This expression is plotted above. For an explosion of 1,000 kilotons, i.e., 1 megaton yield, it can be found from the above graph that significant local fallout is probable for heights of burst less than about 2,900 feet. It should be emphasized that the heights of burst estimated in this manner are approximations only, with probable errors of +30 percent. Furthermore, it must not be assumed that if the burst height exceeds the value in the graph there will definitely be no local fallout. The amount, if any, maybe expected, however, to be small enough to be tolerable under emergency conditions.

main-qimg-a888f0306c3c03264a6f0e30523c10

.001 seconds

It is apparent that the kinetic energy of the fission fragments, constituting some 85 percent of the total energy released, will distribute itself between thermal radiation, on the one hand, and shock and blast, on the other hand, in proportions determined largely by the nature of the ambient medium. The higher the density of the latter, the greater the extent of the coupling between it and the energy from the exploding nuclear weapon. Consequently, when a burst takes place in a medium of high density, e.g., water or earth, a larger percentage of the kinetic energy of the fission fragments is converted into shock and blast energy than is the case in a less dense medium, e.g., air. At very high altitudes, on the other hand, where the air pressure is extremely low, there is no true fireball and the kinetic energy of the fission fragments is dissipated over a very large volume. In any event, the form and amount in which the thermal radiation is received at a distance from the explosion will depend on the nature of the intervening medium.

At very early times, beginning in less than a microsecond, an "inner" shock wave forms driven by the expanding bomb debris. This shock expands outward within the isothermal sphere at a velocity exceeding the local acoustic velocity. The inner shock overtakes and merges with the outer shock at the fireball front shortly after hydrodynamic separation. The relative importance of the debris shock wave depends on the ratio of the yield to the mass of the exploding device and on the altitude of the explosion

main-qimg-c8f4b1e2d14f720e5188db0cc23dcb

.001 seconds

main-qimg-5ab85c8f49126bbd5772e03706fe5e

.001 seconds

main-qimg-1f396ebbc5e30fde0a58afb490ab9d

Explosion at .001 seconds. The support tower in the image above provides a convenient size scale. Most of the above images capture the fireball when it is 100 feet in diameter.

At this stage of the detonation the surface of the fireball has a temperature of 20,000 degrees, three times hotter than the sun's surface. The spikes in the above images are a result from the guide wires supporting the tower on which the bomb was located absorbing enough heat to turn into light emitting plasma. Because thermal radiation travels faster than the fireball, the spikes extend out ahead of it.

main-qimg-781bf809326cf8f08c59b293560222

a few milliseconds old you can see the shockwave hitting the desert floor in front of the fireball and bouncing back. Various trucks and tanks are scattered on the desert floor for the test

main-qimg-f3b4e8cd08de4be8420cc40f52ea27

Just touching the ground

main-qimg-370412435c495379a8665ac6f7f86f

.010 seconds The uneven surface of these explosions has been attributed to variations in the bomb construction, thickness and materials as they are vaporized and turn into this expanding shell of plasma, fire and various gasses.

A primary form of energy from a nuclear explosion is thermal radiation. Initially, most of this energy goes into heating the bomb materials and the air in the vicinity of the blast. Temperatures of a nuclear explosion reach those in the interior of the sun, about 100,000,000° Celsius, and produce a brilliant fireball.

Two pulses of thermal radiation emerge from the fireball. The first pulse, which lasts about a tenth of a second, consists of radiation in the ultraviolet region. The second pulse which may last for several seconds, carries about 99 percent of the total thermal radiation energy. It is this radiation that is the main cause of skin burns and eye injuries suffered by exposed individuals and causes combustible materials to break into flames.

For some time the fireball continues to grow in size at a rate determined by the propagation of the shock front in the surrounding air. During this period the temperature of the shocked air decreases steadily so that it becomes less opaque. Eventually, it is transparent enough to permit the much hotter and still incandescent interior of the fireball, i.e., the isothermal sphere, to be seen through the faintly visible shock front. The onset of this condition at about 15 milliseconds (0.015 second) after the detonation of a 20-kiloton weapon, for example, is referred to as the "breakaway."

Following the breakaway, the visible fireball continues to increase in size at a slower rate than before, the maximum dimensions being attained after about a second.

main-qimg-2d3d189bbdd1653a1d004ffd7d08f5

.016 seconds

The Trinity explosion, 16 ms after detonation. The viewed hemisphere’s highest point in this image is about 200 metres (660 ft) high.

As the fireball cools, the transfer of energy by radiation and radiative growth become less rapid because of the decreasing mean free path of the photons. When the average temperature of the isothermal sphere has dropped to about 300,000°C, the expansion velocity will have decreased to a value comparable to the local acoustic (sound) velocity. At this point, a shock wave develops at the fireball front and the subsequent growth of the fireball is dominated by the shock and associated hydrodynamic expansion. The phenomenon of shock formation is sometimes called "hydrodynamic separation." For a 20-kiloton burst it occurs at about a tenth of a millisecond after the explosion when the fireball radius is roughly 40 feet

main-qimg-cc665a79b4aa6c39f4464ecd6786e8

at .o25 seconds … having expanded to a 1000 ft in diameter the double shock wave is apparent on the expanding edges

main-qimg-6add8e467079996ff36843b00a37c7
main-qimg-64f04a8e266f685c9f2897528a29bc
main-qimg-cb687825fee43c3402f3526c186e65
main-qimg-f558bb9af35ffeaf387dd11ebcfbc9
main-qimg-b0137f6e6dce7fd4800e427a457596
main-qimg-4b8b2b745f9be358e8364418ec6b93
main-qimg-63090b5efc33e3b53a6184add74fee
main-qimg-bce21941d683556033161ac60a7392
main-qimg-d91414e8a64ec86df7dd591dd08d0a

Trinity test ground zero after blast.

The original test report from Los Alamos Trinity test http://permalink.lanl.gov/object...

 

 

Hydrogen bomb sequence coming.

Redwing H-Bomb detonation on a barge at Bikini atoll in Operation Redwing in 1956.

main-qimg-43da0d66adb5c1101874ce82a726dfb2-c.jpeg

A Question of Scale

main-qimg-6b9bf7f6dcf89c17500145c9860245
main-qimg-bb41204e3927cdf5f930b5696074a0

Castle Bravo Sequence

On March 1, 1954, it was the highest yield test in the United States’ highest-yield nuclear test series, exploding with a force of 15 million tons of TNT.

http://www.dtra.mil/Portals/61/D...
main-qimg-79945e7b7f4761908280582e18b110

Castle BRAVO, 3.5 seconds after detonation, photo taken from a distance of 75 nautical miles from ground zero, from an altitude of 12,500 feet.

main-qimg-aa4f39283e19ec2e7ca6d507eea3e3

Castle BRAVO, 62 seconds after detonation. “This image was take at a distance of 50 [nautical miles] north GZ from an altitude of 10,000 feet. The lines running upward to the left of the stem and below the fireball are smoke trails from small rockets. At this time the cloud stem was about 4 mi in diameter.”

main-qimg-be8ec067bba692f9130915b6aac458

Castle BRAVO, 16 minutes after detonation, seen from a distance of 50 nautical miles, at an altitude of 10,000 feet.

This is a work in progress … I will be adding to it

Trinity science details taken from Scientific Aspects of Nuclear Explosion Phenomena

For a current assessment of the threat of nuclear destruction go here Allen E Hall's answer to How destructive is the World's nuclear arsenal?

 

Allen E. Hall

 

Share this post


Link to post
Share on other sites

... and conversely, more lives have been saved by using nuclear radiation in medicine, than everybody ever harmed or killed by the same, starting with Madam Curie isolating Plutonium, by a factor of several hundreds  of thousands of people, well into the millions since 1945.

Share this post


Link to post
Share on other sites

Join the conversation

You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Similar Content

    • Guest
    • By Bible Speaks
      Doomsday Fears Loom to a
      Large Nuclear War?
      One nuclear explosion can instantly obliterate a city—a somber fact that was demonstrated twice in August 1945. A nuclear explosion is horrendously powerful, destroying and killing by means of blast wave, wind, heat, fire, and radiation. Radiation also contaminates food and water. 
      A nuclear war would cause tons of dust to be thrown into the air, blocking sunlight and causing global temperatures to plummet. Food crops and other plants would die. Without food to eat, humans and animals would die of starvation. Some nine countries are said to have the capacity to launch nuclear attacks. A few other nations appear to be in the process of developing their own nuclear weapons. And terrorist organizations are only too eager to get hold of them.
      “Nuclear weapons remain the gravest and most immediate threat to human civilization. . . . There are still some 25,000 nuclear weapons worldwide . . 

      Eventually, terrorists will get the bomb.”—Union of Concerned Scientists.
      Bible’s version of what the future holds paints a more reasonable picture. According to the Bible, for a certainty, a great change is coming. But survival is guaranteed to all who do God’s will. 
      Furthermore, the Bible does not foretell that the earth will be blasted to a cinder or frozen like an ice cube. It will be transformed into a global paradise.
      Will the earth and the human race be destroyed?
      “The righteous themselves will possess the earth, and they will reside forever upon it.”—Psalm 37:29.
      Will any humans lose their lives?
      “The upright are the ones that will reside in the earth, and the blameless are the ones that will be left over in it. As regards the wicked, they will be cut off from the very earth; and as for the treacherous, they will be torn away from it.”—Proverbs 2:21, 22.
      Has God acted against ungodly people in the past?
      God “did not hold back from punishing an ancient world, but kept Noah, a preacher of righteousness, safe with seven others when he brought a deluge upon a world of ungodly people; and by reducing the cities Sodom and Gomorrah to ashes he condemned them, setting a pattern for ungodly persons of things to come.”— 2 Peter 2:5, 6.
      Can we know the date when God’s judgment will come?
      “Concerning that day and hour nobody knows, neither the angels of the heavens nor the Son, but only the Father. For just as the days of Noah were, so the presence of the Son of man will be. For as they were in those days before the flood, eating and drinking, men marrying and women being given in marriage, until the day that Noah entered into the ark; and they took no note until the flood came and swept them all away, so the presence of the Son of man will be.”—Matthew 24:36-39.
      Though the Scriptures give us but a glimpse of what lies ahead, they assure us that humanity is not doomed. The future will be glorious beyond our ability to comprehend. You can count on that, confident that what Jehovah God has promised, he is also able to do.
      How is the earth also protected?
      Van Allen radiation belts (cross section)
      A radiation belt is a zone of energeticcharged particles, most of which originate from the solar wind that is captured by and held around a planet by that planet's magnetic field. The Earth has two such belts and sometimes others may be temporarily created. The discovery of the belts is credited to James Van Allen, and as a result the Earth's belts are known as the Van Allen belts. Earth's two main belts extend from an altitude of about 1,000 to 60,000 kilometers above the surface in which region radiation levels vary. Most of the particles that form the belts are thought to come from solar windand other particles by cosmic rays.[1] By trapping the solar wind, the magnetic field deflects those energetic particles and protects the Earth's atmosphere from destruction.
      The belts are located in the inner region of the Earth's magnetosphere. The belts trap energetic electrons and protons. Other nuclei, such as alpha particles, are less prevalent. The belts endanger satellites, which must have their sensitive components protected with adequate shielding if they spend significant time in that zone. In 2013, NASA reported that the Van Allen Probes had discovered a transient, third radiation belt, which was observed for four weeks until it was destroyed by a powerful, interplanetary shock wavefrom the Sun.[2]
      NOW ARE YOU IN FEAR OF NUCLEAR WAR OR DEVASTATION OF OUR PLANET? 
      Rest your hope in a all-wise loving Creator that will not let the righteous be destroyed or his beautiful earth be destroyed with all living things. 
      God made the earth to be inhabited by humans—to be a lush, global paradise of delight, not a wasteland. Isaiah 45:18 describes Jehovah as “the Creator of the heavens, He the true God, the Former of the earthand the Maker of it, He the One who firmly established it, who did not create it simply for nothing, who formed it even to be inhabited.”
      God has long promised that humans who choose to obey him would reside forever on this earth in peace. Micah 4:4 promises: “They will actually sit, each one under his vine and under his fig tree, and there will be no one making them tremble; for the very mouth of Jehovah of armies has spoken it.” Thus, according to God’s purpose, the earth must remain eternally as mankind’s home, or else his promises would be in vain.—Psalm 119:90; Isaiah 55:11; 1 John 2:17.
      IMG_3815.MP4



    • By Bible Speaks
      FEAR OF NUCLEAR WAR NOW COULD MEAN DESTRUCTION OF THE EARTH AND ALL LIFE? Will these nations on the horizon fulfill their efforts to destroy all life?
      Does God care? What now? 
       Human efforts at unity—no matter how sincere—have proved futile. This comes as no surprise to Bible students, for God’s Word says: “It does not belong to man who is walking even to direct his step.” (Jeremiah 10:23) 
      The Bible also candidly states: “There exists a way that is upright before a man, but the ways of death are the end of it afterward.” (Proverbs 16:25) 
      Human governments can go only so far in achieving unity. Still, we are not left without hope.
      The Source of True Unity
      The Bible contains God’s promise that the world will be unified but not by man’s efforts. The Creator, who purposed that mankind would live in peace worldwide, will accomplish what man cannot. To some, all of that might seem far-fetched. 
      Yet, God’s purpose from the very beginning has been for mankind to live in peace and harmony.
      Many scriptures in the Bible give evidence that bringing the human race into a unified condition is still God’s purpose. Consider just a few examples:
      • “Come, you people, behold the activities of Jehovah, how he has set astonishing events on the earth. He is making wars to cease to the extremity of the earth. The bow he breaks apart and does cut the spear in pieces; the wagons he burns in the fire.”—PSALM 46:8, 9.
      • “They will not do any harm or cause any ruin in all my holy mountain; because the earth will certainly be filled with the knowledge of Jehovah as the waters are covering the very sea.”—ISAIAH 11:9.
      • “He will actually swallow up death forever, and the Sovereign Lord Jehovah will certainly wipe the tears from all faces. And the reproach of his people he will take away from all the earth, for Jehovah himself has spoken it.”—ISAIAH 25:8.
      • “There are new heavens and a new earth that we are awaiting according to his promise, and in these righteousness is to dwell.”—2 PETER 3:13.
      • “[God] will wipe out every tear from their eyes, and death will be no more, neither will mourning nor outcry nor pain be anymore. The former things have passed away.”—REVELATION 21:4.
      These promises are reliable. Why? Because as the Creator, Jehovah God has the power and the ability to bring unity to mankind. (Luke 18:27) 
      He also has the desire to do so. In fact, the Bible calls it God’s “good pleasure . . . to gather all things together again in the Christ, the things in the heavens and the things on the earth.”—Ephesians 1:8-10.
      God’s promise of “a new earth” in which “righteousness is to dwell” is not mere wishful thinking. (2 Peter 3:13) 
      Regarding what he promised, Jehovah God states: “It will not return to me without results, but it will certainly do that in which I have delighted, and it will have certain success in that for which I have sent it.”—Isaiah 55:11.
      #jworg #jehovahgod 

  • Who Was Online   95 Users were Online in the Last 24 Hours   (Most members ever online in 24 hour was 97, last accomplished on .)

  • Forum Statistics

    58,504
    Total Topics
    103,643
    Total Posts
  • Member Statistics

    15,869
    Total Members
    1,592
    Most Online
    Torso Boy
    Newest Member
    Torso Boy
    Joined




×
×
  • Create New...

Important Information

Terms of Service Confirmation Terms of Use Privacy Policy Guidelines We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.