DEUTERIUM AND THE DENSITY OF THE COSMOS
During the nuclear epoch, although most deuterium was quickly fused into helium as soon as it formed, a small amount was left over when the primordial nuclear reactions ceased.
deuterium
an isotope of hydrogen; its nucleus, consisting of one proton and one neutron, has double the mass of the nucleus of ordinary hydrogen
diffraction ...
Deuterium
(a) Hydrogen-2, the rare heavy isotope of hydrogen. Deuterium has one proton and one neutron, whereas normal hydrogen has one proton and no neutrons.
DEUTERIUM - Isotope of hydrogen whose nucleus contains one proton and one neutron. As a trace element formed during the nucleosynthesis epoch of the Big Bang, deuterium is an important indicator of the baryon density in the universe.
Deuterium - An isotope of hydrogen. The nucleus of a deuterium atom is a deuteron
Deuteron - A nucleus of deuterium, an isotope of hydrogen. A deuteron contains one proton and one neutron ...
Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6500 of hydrogen ....
, an isotope
Isotope ...
Deuterium is a byproduct of the nuclear reactions that took place throughout the universe about a minute after the beginning of time.
deuterium nucleus mass
3.3435860× 10-24 grams
= 2.013553214 amu
Go to Planet Tables ...
deuterium An isotope of hydrogen in which there is a neutron bound to the proton in the nucleus. Often called "heavy hydrogen" because of the extra mass of the neutron.
Deuterium
A special form of hydrogen (an isotope called "heavy hydrogen") that has a neutron as well as a proton in its nucleus.
Doppler Effect ...
Deuterium can also be produced by the rare pep (proton-electron-proton) reaction (electron capture):
1H
+ ...
deuterium - (n.)
An isotope of hydrogen with a proton and a neutron in the nucleus (mass of 2 amu).
differential gravitational force - (n.) ...
Using deuterium-tritium fuel, the resulting energy barrier is about 0.01 MeV. In comparison, the energy needed to remove an electron from hydrogen is 13.6 eV, about 750 times less energy.
helium, deuterium, and a few other elements form
380,000 years
Recombination (Decoupling) ...
On , the deuterium/hydrogen and 16O/18O ratios imply that warmer temperatures existed on in the past.
Hydrogen-deuterium absorption cell channel: measures relative abundance of hydrogen and deuterium from Lyman-Alpha emission, using resonance absorption cells. Channel electron multiplier detector records photons not absorbed in cells.
Producing deuterium by fission is also difficult. The problem here again is that deuterium is very subject to nuclear processes, and that collisions between atomic nuclei are likely to result either in the absorption of the nuclei, ...
deuterium (NASA Thesaurus / NASA SP-7, 1965) (symbol D, d)
A heavy isotope of hydrogen having one proton and one neutron in the nucleus.
The symbol D is often used to designate deuterium in compounds, as HDO for molecules of that composition.
080 solar masses (13 to 80 Jupiter-masses): too small for normal nuclear fusion but big enough to fuse deuterium. Brown dwarfs are larger than planets but smaller than stars. C ...
In fusion research, where deuterium-tritium is a common fuel mixture, the neutron released when (D + T) combine to form (4He + n) can activate the reactor structure.
During the early 1950s American researchers produced the hydrogen bomb by inducing fusion reactions in a mixture of the heavy hydrogen isotopes deuterium and tritium, ...
Hydrogen-1 (one proton and no neutrons) is the most common isotope; hydrogen-2 (one proton and one neutron), or deuterium, is rarer; and hydrogen-3 (one proton and two neutrons), or tritium, is radioactive. [C95] ...
Peacock's one great claim to astronomical fame is a measure of an upper limit to its deuterium (a heavy form of hydrogen) abundance.
The abundances of the lightest elements (hydrogen, helium, deuterium, lithium) are consistent with their creation in a Big Bang event and not via subsequent nucleosynthesis in stars.
In 1989, the astronomers D'Alessio and Harms suggested that some of the deuterium in a comet entering the Earth's atmosphere may have undergone a nuclear fusion reaction, leaving a distinctive signature in form of carbon-14.
When brown dwarfs are very young, they are relatively luminous because they do generate some radiative energy from the fusion of deuterium ("heavy hydrogen") into helium nuclei, which is used up in a few tens of millions of years.
Objects just below this limit are called brown dwarfs, because, while they cannot fuse hydrogen, they can fuse deuterium, the two-nucleon isotope of hydrogen.
minor atmospheric components, especially organic molecules; determine the spatial distribution of aerosols and clouds in Titan's atmosphere; establish noble gas abundances and isotopic rations in the atmosphere, especially the ratio of deuterium to ...
where the symbols stand for Hydrogen with one proton (1H), hydrogen with a proton and a neutron (2H), also known as deuterium, a positron (e+) which is the positively charged antimatter form of an electron, and a neutrino.
Using the Big Bang model it is possible to calculate the concentration of helium 4, helium 3, deuterium and lithium 7 in the universe. All the abundances depend on a single parameter, the ratio of photons to baryons.
Another difference is indicated by the presence of deuterium (D) on Jupiter. This heavy isotope of hydrogen has disappeared from the Sun as a result of nuclear reactions in the solar interior.
One interesting consequence of Jeans escape is the ratio of deuterium (D) to hydrogen (H) observed in the atmosphere of the planet Venus. The D/H ratio on Earth is about 100 times less than that seen on Venus.
In the proton-proton cycle, two hydrogen nuclei (protons) are fused and one of these protons is converted to a neutron by beta decay (see radioactivity) to make a deuterium nucleus (one proton and one neutron).
In hydrogen they contain just one proton, in heavy hydrogen ("deuterium") a proton and a neutron; in helium, two protons and two neutrons, and in carbon, nitrogen and oxygen--6, 7 and 8 of each particle, respectively.
In the first step two protons collide to produce deuterium, a positron, and a neutrino. In the second step a proton collides with the deuterium to produce a helium-3 nucleus and a gamma ray.
In 2374, the USS Voyager was forced to land on a class Y planet in the Vaskan sector after detecting desperately needed deuterium on the surface.
Stars do not produce any deuterium, but they do create some additional helium by burning hydrogen. This means that all the deuterium and most of the helium we see today comes from the birth of the universe.
Hydrogen (deuterium) helium and some lithium were created by nucleosynthesis just after the Big Bang. The next heaviest elements (like carbon, nirogen, and oxygen) are formed inside stars via fusion. Most stars fuse hydrogen, forming helium.
Comets and Earth's oceans both contain a small amount of so-called "heavy water" composed of equal parts hydrogen, oxygen, and deuterium.
Hydrogen (deuterium) helium and some lithium were created by just after the . The next heaviest elements (like carbon, nirogen, and oxygen) are formed inside stars via . Most stars fuse hydrogen, forming helium.
A third optical path with a solar blind CsI photocathode is used for a high signal-to- noise ratio, stellar occultation by rings and atmospheres. A separate hydrogen deuterium absorption cell measures the relative abundance of deuterium and hydrogen ...
of Characteristics of the Atmosphere of Venus) and VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) instruments on the European Space Agency mission have shown that the ratio of heavy water (which contains the isotope deuterium instead of ...
Primordial nucleosynthesis occurred very early in the history of the Universe, resulting in some helium and small traces of lithium and deuterium, the heavy isotope of hydrogen.
of the abundances of these elements can give scientists important clues to the nature and evolution of the early Universe. In particular, measurement of the ratio of the normal isotope of hydrogen to its heavier isotope known as deuterium will ...
The nucleosynthesis period effectively begins when the characteristic photon energy is too low for photodissociation of deuterium, which is at T ~8 × 108 K.
If these neutral or ionized species possess enough energy, they can escape the gravitational pull of Mars, resulting in a net atmospheric loss. Measurements of lighter species such as atomic hydrogen and deuterium also can provide clues about the ...
 See also: Light, Hydrogen, Mass, Element, Energy
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