Green Energy: Fusion Reactors and Planetary
Exploration
The Editor, Space and Astronautics News http://space.gs
image credit: NASA
I have for some time advocated the mining of Helium 3 from the Moon as a
source of stable material for use in fusion reactors. (A present, a Helium 2
fusion has to be shut down after a few seconds to avoid further cracking the
reactor walls.) Roscosmos has a �Moon Gas Project�. To borrow from JFK: �We
choose to go to the Moon in this decade and to do the other things, not because
they are easy, but because?� of Helium 3! There is almost no Helium 3 on Earth,
but it is abundant on rocky bodies in the Solar System, including the Moon and
asteroids. It could provide an extremely cheap and sustainable energy source
with no used material disposal problems and no danger to the public from
radiation. NASA are planning to not only land a
manned Altair spacecraft on
the Moon, but also on an asteroid. STFC are following a slightly different tack
in this press release, while still advocating planetary exploration: -
�Secrets from within planets pave way for cleaner energy
- Science and
Technology Facilities Council:-
Research that has provided a deeper understanding into the centre of planets
could also provide the way forward in the world�s quest for cleaner energy. An
international team of scientists, led by the University of Oxford, working
alongside researchers at the Science and Technology Facilities Council�s (STFC)
Central Laser Facility, has gained a deeper insight into the hot, dense matter
found at the centre of planets and as a result, has provided further
understanding into controlled thermonuclear fusion. The full paper on this
research has been published, 19 October, in the scientific journal, Nature
Physics.
This deeper insight into planets could extend our comprehension of fusion
energy - the same energy that powers the sun, and laser driven fusion as a
future energy source. Fusion energy is widely considered an attractive,
environmentally clean power source using sea water as its principal source of
fuel, where no greenhouse gasses or long lived radioactive waste materials are
produced.
Using STFC�s Vulcan laser, the team has used an intense beam of X-rays to
successfully identify and reproduce conditions found inside the core of planets,
where solid matter has a temperature in excess of 50,000 degrees. The
understanding of the complex state of matter in these extreme
conditions
represents one of the grand challenges of contemporary physics.
The results from the Vulcan experiments are intended to improve our models of
Jupiter and Saturn and to obtain better constraints on their composition and the
age of the Solar System. Using inelastic X-ray scattering measurements on a
compressed lithium sample, it was shown how hot, dense matter states can be
diagnosed and
structural properties can be obtained. The thermodynamic
properties -
temmperature, density and ionisation state, were all measured
using a combination of non-invasive, high accuracy, X-ray diagnostics and
advanced numerical simulations. The experiment has revealed that the matter at
the centre of planets is in a state that is intermediate between a solid and a
gas over lengths larger than 0.3 nanometres. To put this into context, 1
nanometre equates to less than 1/10000th of a human hair! Results showed that
extreme matter behaves as a charged liquid, but at smaller distances it
acts
more like a gas.
Dr Gianluca Gregori, of the University of Oxford and STFC�s Central Laser
Facility said: �The study of warm dense matter states, in this experiment on
lithium, shows practical applications for controlled thermonuclear
fusion,
and it also represents significant understanding relating to astrophysical
environments found in the core of planets and the crusts of old stars. This
research therefore makes it not only possible to formulate
more accurate
models of planetary dynamics, but also to extend our comprehension of controlled
thermonuclear fusion where such states of matter, that is liquid and gas, must
be crossed to initiate fusion
reactions. This work expands our knowledge of
complex systems of particles where the laws that regulate their motion are both
classical and quantum mechanical. �
Professor Mike Dunne, Director of the Central Laser Facility at STFC said:
�Using high power lasers to find solutions to astrophysical issues is an area
that has been highly active at STFC for some time. We are very excited that the
Vulcan laser has contributed to such a significant piece of research. The use of
extremely powerful lasers is proving to be a particularly effective approach to
delivering long-term solutions for
carbon-free energy.�
This research paper has been published as an advance online publication
at
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys1103.html
Posted by email from Space�s posterous
Earlier global warming produced a whole new form of life
POSTED: Wednesday, October 22, 2008
FROM BLOG: Science Codex - Science Codex is one source for all of the latest science news in culture, technology, earth sciences,physical sciences, space science and technology.
The following blog post is from an independent writer and is not connected with Reuters News. The opinions and views expressed herein are those of the author and are not endorsed by Reuters.com.
Researchers from McGill University, along with colleagues from the California Institute of Technology, the Curie Institute in Paris, Princeton University and other institutions, have unearthed crystalline magnetic fossils of a previously unknown species of microorganism that lived at the boundary of the Paleocene and Eocene epochs, some 55 million years ago. Their results were published Oct. 21 in the Proceedings of the National Academy of Sciences.
The research might help scientists understand more thoroughly the potential effects of significant changes in the Earth's climate.
Though they are only some four microns long, these newly discovered, spear-shaped magnetite crystals (magnetofossils) � unearthed at a dig in New Jersey � are up to eight times larger than previously known magnetofossils. Magnetofossils are remnants of magnetite crystals produced by a type of bacteria called magnetotactic bacteria that are capable of orienting themselves along the direction of the Earth's magnetic field.
The new fossils are "unlike any magnetite crystal ever described," the study's first author Dirk Schumann � a graduate student at McGill's Department of Earth and Planetary Sciences � told Nature News.
"Previous reports suggested that the source of the magnetic signature in the boundary layer was a type of magnetite that was formed by the impact of a comet," said lead researcher and corresponding author Dr. Hojatollah Vali. "In our previous paper we proved that the magnetic signature comes from biogenic material.
"This is an entirely new class of organism that no one has reported before," explained Vali, a professor jointly appointed in McGill's Departments of Anatomy and Cell Biology and Earth and Planetary Sciences. "When my colleagues and I first discovered magnetofossils in deep-sea sediments in the mid-1980s, we knew already that magnetotactic bacteria produced magnetite and then we looked for the magnetofossils. In our new study, we discovered the magnetofossils first without knowing the organism."
This species of microorganism, explained Vali, lived during a period of abrupt global warming known as the Paleocene-Eocene Thermal Maximum (PETM), when worldwide temperatures rose by 5� to 6� C over a period of 20,000 years.
"What's very interesting is that we know the very specific time frame when these organisms existed," he said. "If you go below it, we don't find them, and if you go above it, we don't find them. Five degrees warmer may not seem like much, but there was much more iron available due to increased weathering. The additional iron is required for the microorganism to produce the giant magnetofossils. It is clear that a similar abrupt global warming climatic event could have a severe impact upon our biosphere."
Source: McGill University
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