Approach one being Philo FArnsworth's fusor and Approach number two being Bubble fusion or sonofusion.
Nuclear Fusion On A Tabletop
http://www.spacedaily.com/reports/Nu..._Tabletop.htmlAn internal view of the vacuum chamber containing the fusion device, showing two pyroelectric crystals that generate a powerful electric field when heated or cooled. Photo by Rensselaer/Danon
by Staff Writers
Rensselaer, NY (SPX) Feb 13, 2006
U.S. researchers said they have developed what is essentially a tabletop particle accelerator that can produce low levels of nuclear fusion at close to room temperature. A team at Rensselaer Polytechnic Institute developed the tiny accelerator using a device called a pyroelectric crystal.
"You just heat the crystal from room temperature to about 130 degrees," team leader Yaron Danon told SpaceDaily.com. "Then you can use it while it's heating or while it's cooling. We're doing it while it's cooling. We're letting it cool back to room temperature, and while it's doing that it's accelerating ions, so it's like a particle accelerator that's very simple."
Danon said the device is so small and efficient it requires only a 6-volt battery, but because it also emits neutrons - which in sufficient numbers can be harmful or deadly - operating it requires caution.
"Currently we are emitting two to the fourth or two to the fifth (neutrons during) a heating cycle, which lasts for about 200 seconds," he explained. "We're several meters away, so the dose rate at that distance is really low. If it gets to be the same amount (of neutrons emitted) for a shorter time, then we have to be very careful."
The device uses a pair of the crystals encased in a chamber of deuterium gas. The crystals create a very strong electric field when they are heated or cooled, and the field produces deuterium ions by ripping electrons from the gas and accelerating them toward a deuterium target on one of the crystals. When a deuterium ion smashes into the target, a neutron is emitted, the telltale sign that nuclear fusion has occurred.
"We published several papers explaining how these crystals produce X-rays and electron beams, and they're very efficient in doing this," Danon said. "So using low-energy X-rays or low-energy electron beams - by which I mean similar to the energies that are used currently in medical imaging rather than treatment - we can produce a really high dose of electrons that can penetrate a very thin layer of the skin. If such a device can produce high enough dose, then we can possibly use it for cancer treatment - and we're not far from this goal."
He said eventually the device could lead to portable, battery-operated neutron generators for a variety of applications, from non-destructive testing to detecting explosives and scanning luggage at airports. "We're trying to figure out better ways to produce more neutrons, and to see how we can use our device for X-rays for imaging applications. We are also trying to develop a higher-dose device for medical applications," he added. "All these applications are using the polarization effect that occurs when heating or cooling pyroelectric crystals."
__________________
"Greater love hath no man than this, that a man lay down his life for his friends." Jesus Christ, John 15:13
Darkblade
View Public Profile
Send a private message to Darkblade
Find all posts by Darkblade
Add Darkblade to Your Buddy List
#2 February 14th, 2006, 6:57 pm
Darkblade
A Great American Join Date: May 2004
Posts: 18,730
Re: Table top Fusion; approach number three
--------------------------------------------------------------------------------
'Double Crystal Fusion' Could Pave The Way For Portable Device
Researchers at Rensselaer Polytechnic Institute have developed a tabletop accelerator that produces nuclear fusion at room temperature, providing confirmation of an earlier experiment conducted at the University of California, Los Angeles (UCLA), while offering substantial improvements over the original design.
An internal view of the vacuum chamber containing the fusion device, showing two pyroelectric crystals that generate a powerful electric field when heated or cooled. (Photo by Rensselaer/Danon)The device, which uses two opposing crystals to generate a powerful electric field, could potentially lead to a portable, battery-operated neutron generator for a variety of applications, from non-destructive testing to detecting explosives and scanning luggage at airports. The new results are described in the Feb. 10 issue of Physical Review Letters.
“Our study shows that ‘crystal fusion’ is a mature technology with considerable commercial potential,” says Yaron Danon, associate professor of mechanical, aerospace, and nuclear engineering at Rensselaer. “This new device is simpler and less expensive than the previous version, and it has the potential to produce even more neutrons.”
The device is essentially a tabletop particle accelerator. At its heart are two opposing “pyroelectric” crystals that create a strong electric field when heated or cooled. The device is filled with deuterium gas — a more massive cousin of hydrogen with an extra neutron in its nucleus. The electric field rips electrons from the gas, creating deuterium ions and accelerating them into a deuterium target on one of the crystals. When the particles smash into the target, neutrons are emitted, which is the telltale sign that nuclear fusion has occurred, according to Danon.
A research team led by Seth Putterman, professor of physics at UCLA, reported on a similar apparatus in 2005, but two important features distinguish the new device: “Our device uses two crystals instead of one, which doubles the acceleration potential,” says Jeffrey Geuther, a graduate student in nuclear engineering at Rensselaer and lead author of the paper. “And our setup does not require cooling the crystals to cryogenic temperatures — an important step that reduces both the complexity and the cost of the equipment.”
The new study also verified the fundamental physics behind the original experiment. This suggests that pyroelectric crystals are in fact a viable means of producing nuclear fusion, and that commercial applications may be closer than originally thought, according to Danon.
“Nuclear fusion has been explored as a potential source of power, but we are not looking at this as an energy source right now,” Danon says. Rather, the most immediate application may come in the form of a battery-operated, portable neutron generator. Such a device could be used to detect explosives or to scan luggage at airports, and it could also be an important tool for a wide range of laboratory experiments.
The concept could also lead to a portable x-ray generator, according to Danon. “There is already a commercial portable pyroelectric x-ray product available, but it does not produce enough energy to provide the 50,000 electron volts needed for medical imaging,” he says. “Our device is capable of producing about 200,000 electron volts, which could meet these requirements and could also be enough to penetrate several millimeters of steel.”
In the more distant future, Danon envisions a number of other medical applications of pyroelectric crystals, including a wearable device that could provide safe, continuous cancer treatment.
Frank Saglime, a graduate student in nuclear engineering at Rensselaer, also contributed to the research. The work was funded through the U.S. Department of Energy’s Nuclear Engineering Education Research (NEER) Program.
Topic: Table Top Fusion; approach number three (Read 1090 times)