Nuclear fusion

Nuclear Fusion

A large atomic nucleus splits up into two nuclei is fission. Two light atomic nuclei combine into one heavy nucleus is nuclear fusion. Fusion may release a nucleon.

Both fission and fusion generally release energy. Hydrogen fusion produces million times more energy than burning hydrogen with oxygen. Fusion reactions power stars such as the Sun. In terms of energy supply, fusion has many advantages:

To achieve nuclear fusion, two light atoms must come within a distance of 10-15 m. The strong force becomes effective at this distance, and the two nuclei unite into one nucleus.

Since atomic nuclei have positive charges, they must overcome the Coulomb potential in order to approach each other within 10-15 m. Thus, the light nuclei must be moving at high speed in their collision. Thus, nuclei are either accelerated or heated to a high temperature.

Fusion research

Particle accelerators invented for the study of nuclear reactions are also wonderful machines for the study of fusion. Accelerated H, D, T, 3He, 4He particles are used to bombard targets of these same nuclides. These experiments provides data about fusion. In particular, the following four reactions receive the most attention. D + T ® 4He + n
D + 3He ® 4He + p
D + D ® 3He + n
D + D ® 3T + p

Probabilities of fusion reactions are quantitatively defined as the cross sections. Effective cross sections for various fusion reactions as functions of temperature are given here. For all four fusion reactions given above, the cross section for the reaction,

D + T ® 4He + n is consistantly the highest at any temperature. This reaction has been choosen in further fusion research, because of its potential for success.

Possible Fusion Reactions

The following criteria are considered for fusion reaction: The following are some important fusion reactions:
D + T -> He4 (3.5 MeV) + n (14.1 MeV)
D + D -> T (1.01 MeV) + p ( 3.02 MeV) (50%)
D + D -> He3 (0.82 MeV) + n ( 2.45 MeV) (50%)
D +He3 -> He4 (3.6 MeV) + p (14.7 MeV)
T +T -> He4 + 2 n + 11.3 MeV
He3+He3 -> He4 + 2 p
He3+T -> He4 + p + n + 12.1 MeV (51%)
He3+T -> He4 (4.8 MeV) + D ( 9.5 MeV) (43%)
He3+T -> He4 (0.5 MeV) + n ( 1.9 MeV) + p (11.9 MeV) (6%)
D +Li6 -> 2 He4 + 22.4 MeV
p +Li6 -> He4 (1.7 MeV) + He3 ( 2.3 MeV)
He3+Li6 -> 2 He4 + p + 16.9 MeV
p +B11 -> 3 He4 + 8.7 MeV
The fusion cross sections are further discussed in Alternate Fusion Fuels.

Fusion Research

Cold Fusion Update


Observations have been made of deuteron-deuteron fusion at room temperature during low-voltage electrolytic infusion of deuterons into metallic titanium or palladium electrodes. Neutrons with an energy of approximately 2.45 meV have been clearly detected with a sensitive neutron spectrometer at a rate of 0.002 n/s which cannot be accounted for by ambient neutron background variations. The reaction has been known to yield excess (or "latent") heat, where D + D yields 4He + 23.8 MeV. This paper examines the latest experimental results from several international researchers and summarize several new theories of nuclear model interactions that have been put forth to explain these intriguing results.

This article is a report of activities.

Cold Fusion Times A megazine for cold fusion science.

Website of the the U.S. Fusion Energy Sciences Program