nuclear fusion

Examples of nuclear fusion in the following topics:

• Nuclear Fusion

  • In nuclear fusion two or more atomic nuclei collide at very high speed and join, forming a new nucleus.
  • The sun is a main-sequence star and therefore generates its energy through nuclear fusion of hydrogen nuclei into helium.
  • Nuclear fusion is a nuclear reaction in which two or more atomic nuclei collide at very high speed and join to form a new type of atomic nucleus.
  • Accelerated to high speeds, they can overcome this electrostatic repulsion and be forced close enough for the attractive nuclear force to be sufficiently strong to achieve fusion.
  • Analyze possibility of the use of nuclear fusion for the production of electricity.

• Nuclear Fusion

  • Nuclear fusion is the process by which two or more atomic nuclei join together to form a single heavier nucleus and large amounts of energy.
  • Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse," to form a single heavier nucleus.
  • The origin of the energy released in fusion of light elements is due to an interplay of two opposing forces: the nuclear force that draws together protons and neutrons, and the Coulomb force that causes protons to repel each other.
  • The nuclear force is stronger than the Coulomb force for atomic nuclei smaller than iron, so building up these nuclei from lighter nuclei by fusion releases the extra energy from the net attraction of these particles.
  • Describe the electrostatic and strong nuclear forces and how they act to oppose or promote a fusion reaction

• Conservation of Nucleon Number and Other Laws

  • Through radioactive decay, nuclear fusion and nuclear fission, the number of nucleons (sum of protons and neutrons) is always held constant.
  • Finally, nuclear fusion follows the Law of Conservation of Nucleon Number.
  • Consider the fusion of deuterium and tritium (both hydrogen isotopes):
  • It is well understood that the tremendous amounts of energy released by nuclear fission and fusion can be attributed to the conversion of mass to energy.
  • Thus, the number of nucleons before and after fission and fusion is always constant.

• The Hydrogen Bomb

  • The hydrogen bomb is a nuclear weapon that uses a mixture of fission and fusion to produce a massive explosion.
  • A thermonuclear weapon is a nuclear weapon designed to use the heat generated by a fission bomb to compress a nuclear fusion stage.
  • The only two nuclear weapons that have been used were both fission-based.
  • The energy released by the primary section compresses the secondary through a process called "radiation implosion," at which point it is heated and undergoes nuclear fusion.
  • The nuclear fusion releases neutrons much faster than a fission reaction, and these neutrons then bombard the remaining fissile fuel, causing it to undergo fission much more rapidly.

• Fusion Reactors

  • A fusion reactor is designed to use the thermal energy from nuclear fusion to produce electricity.
  • Fusion power is the power generated by nuclear fusion processes.
  • This is similar to the process used in fossil fuel and nuclear fission power stations.
  • Above this atomic mass, energy will generally be released by nuclear fission reactions; below this mass, energy will be released by fusion.
  • According to the Lawson criterion, the easiest and most immediately promising nuclear reaction for fusion power is:

• Nuclear Weapons

  • A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions—either fission, fusion, or a combination.
  • A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion.
  • The first fusion (i.e., thermonuclear "hydrogen") bomb test released the same amount of energy as approximately 10,000,000 tons of TNT.
  • In addition, it is also widely believed that Israel possesses nuclear weapons (though they have not admitted to it).
  • The first nuclear weapons were gravity bombs, such as this "Fat Man" weapon dropped on Nagasaki, Japan.

• Nuclear Fission in Reactors

  • Nuclear reactors convert the thermal energy released from nuclear fission into electricity.
  • Nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller (lighter) nuclei.
  • This is known as a nuclear chain reaction.
  • Nuclear safety involves the actions taken to prevent nuclear and radiation accidents or to limit their consequences.
  • An induced nuclear fission event.

• Nuclear Weapons

  • The proliferation of nuclear weapons, explosive devices which derive force from nuclear reactions, is a key challenge of foreign policy.
  • The proliferation of nuclear weapons, explosive devices which derive their destructive force from nuclear reactions (either fission or a combination of fission and fusion), is an important challenge of foreign policy.
  • By the 1960s, steps were being taken to limit both the proliferation of nuclear weapons to other countries and the environmental effects of nuclear testing.
  • The Partial Test Ban Treaty (1963) restricted all nuclear testing to underground facilities, to prevent contamination from nuclear fallout, while the Nuclear Non-Proliferation Treaty (1968) attempted to place restrictions on the types of activities signatories could participate in, with the goal of allowing the transference of non-military nuclear technology to member countries without fear of proliferation.
  • Identify the history of nuclear weapons and international efforts to regulate them

• Nuclear Binding Energy and Mass Defect

  • This energy—available as nuclear energy—can be used to produce nuclear power or build nuclear weapons.
  • Nuclear binding energy is also used to determine whether fission or fusion will be a favorable process.
  • For elements lighter than iron-56, fusion will release energy because the nuclear binding energy increases with increasing mass.
  • As such, there is a peak at iron-56 on the nuclear binding energy curve.
  • Calculate the mass defect and nuclear binding energy of an atom

• Endosymbiotic Theory and the Evolution of Eukaryotes

  • Genome fusion occurs during endosymbiosis, which is the mechanism proposed as responsible for the first eukaryotic cells.
  • Nuclear and mitochondrial DNA are thought to be of different (separate) evolutionary origin, with the mitochondrial DNA being derived from the circular genomes of bacteria that were engulfed by ancient prokaryotic cells.
  • An endosymbiotic fusion event would clearly explain this observation.
  • Some bacteria have the DNA enclosed by two membranes; however, there is no evidence of a nucleolus or nuclear pores.
  • Describe the genome fusion hypothesis and its relationship to the evolution of eukaryotes