February 17, 2008

This is from the front page of today's Gulf News, of Dubai, United Arab Emirates.

January 12, 2008

* Big microscope focuses on small stuff | $27 million unit can image individual atoms
Betsy Mason, San Gabriel Valley Tribune (CA)

"It's beyond the state of the art." That's how materials scientist Ulrich Dahmen, head of the National Center for Electron Microscopy at Lawrence Berkeley National Laboratory describes a new electron microscope. The first phase of putting the instrument together in Berkeley was completed last month and Dahmen hopes to be able to test it in a month or so, once it has been calibrated. Later this year, the microscope will be available to scientists around the world who apply to use it. The 12-foot tall microscope has more than a dozen magnetic lenses that help focus the electron beam. Each lens has its own power source, which must be incredibly stable with no fluctuations. The technology behind the new microscope's power sources was only developed last year. The new $27 million microscope has a resolution of half of an angstrom, or 300 billionths of a foot, and can image and identify individual atoms. "It's doubling the resolution of the best microscope we have here," Dahmen said. To put the power of the half-angstrom resolution in perspective, atoms are usually spaced a couple of angstroms apart. Looking at things as small as an atom requires an extremely quiet, stable environment. The room that houses the microscope will be sealed off with no air flow and no noise interference, and held at a constant temperature. It has slanted walls to reduce acoustic noise, is separated from the rest of the building that surrounds it and cost $1 million to construct. The next stage of the project is construction of a second microscope at the lab that has all the capabilities of the first, with some additional improvements, including 3-D capability. "We're on the verge of visualizing atomic images in three dimensions," according to John Spence, a condensed metaphysicist at Arizona State University in Tempe. "In the past, electron microscopes have always shown a projection, a two-dimensional image." The result will be the ability to map out exactly where every atom is in a material. The full capability of the second microscope probably won't be known until it is finished in 2009. But even the first microscope by itself holds much promise. For example, it is expected that the microscope will help scientists discover and shape new atomic-scale nanostructures that could lead to better materials for a whole range of products from airplanes to cosmetics. Another area that could benefit is the conversion of oil into gasoline, potentially saving billions of dollars.

October 4, 2005

Particle Accelerators - outcome of research is every bit as important as Manhattan Project was

Classified defense projects are focusing on creating particles that can be switched between virtual and real modes using very advanced classified particle physics. Some papers are available on these technologies but they are vague and contain little information. Some countries are said to be spending countless billions on these technologies and the outcome is as serious as nuclear bombs. This article discusses the implications of this research on "stealth" technology. It matter-of-factly asserts that "... scientists realize the best stealth is to make an object really disappear. That is what the extraterrestrial UFOs have been doing for thousands of years evading all possible terrestrial technologies. What extraterrestrial UFOs from advanced aliens in the cosmos or Hyperspace do is to transform the materials from real to virtual mode in the 3-D Physical Universe. Particles can exist in 5-dimensions, which is real in Hyperspace or in 3-D, which is real in Physical Hyperspace. Switching particles between 3-D to 5-D and vice versa is what makes the ultimate stealth possible. The advanced alien technologies of switching back and forth between 3-D and 5-D is not easy to attain using the realm of terrestrial particle physics. However the large massive super accelerating particle colliders are providing the first clues to the advanced technologies of switching particles between real and virtual mode in out 3-D Physical universe."

[Ref: India Daily Technology Team, "The biggest secret projects - reverse engineering extraterrestrial advanced stealth technologies from UFOs", Indiadaily.com, October 4, 2005]

July 5, 2004

Small desalination solutions - manual & solar-powered

The Central Salt and Marine Chemicals Research Institute [CMSCRI] in India has developed an ox driven desalination plant capable of producing 600 to 700 litres of potable water per hour. All it takes is Rs 2.5 lakhs per plant and a sturdy pair of oxen; no power, no pipelines, no canals. CMSCRI director Dr P K Ghosh says that a unit is already operating in Bengal's 24-Parganas district and several more are being planned for border areas of Rajasthan. Katadyn also makes an electric model that consumes just 50 watts at 12 volts, making it suitable for running off solar panels. This produces 6 litres per hour. It can also revert to manual operation in emergencies.

[Source: "People-sized desalination", GoodNewsIndia, July 5, 2004]

June 7, 2004

Nuclear microchip batteries

Researchers Amit Lal of Cornell University and James Blanchard of the University of Wisconsin at Madison use a sort of microscopic seesaw to intercept the particles hurled from the atoms in radioactive nickel; the particles set the seesaw swinging, and that motion is converted into a billionth of a watt of electricity--enough to drive tiny embedded sensors that might warn of intruders in a maintenance tunnel or detect an epileptic seizure. In a few years, the tiny current would build up enough juice to fire off a cell phone call. That could make nuclear chips, which can last 100 years, the power of choice for emergency phones and other devices that might have to sit untended for a decade or more.

[Source: David H. Freedman, "Pocket Full of Power", Newsweek,Ê June 7, 2004,Êp.Ê63 (subscription required)]

October 28, 2003

Like planets? Some scientists think nuclear reactions are the source of most heavy elements

A survey of 754 nearby Sun-like stars has shown that stars with a high content of elements heavier than helium -- "metals" -- are more likely to form planets Debra Fischer (UC-Berkeley) explains, "Astronomers note that only 5 percent of all stars have planets. But we now know that of the stars abundant in heavy metals, 20 percent have planets. That's stunning."

Elements heavier than helium are created by nuclear reactions in stars and ejected into the interstellar medium through supernova explosions. Metals were rare in the early Milky Way, but each successive stellar generation has more heavy elements as interstellar gas is recycled. This means new stars have better chances of making planets because heavier elements coalesce more easily, allowing dust, rocks, and planetesimals to form.

[Source: A.H. (news writer) Astronomy, "Metals make planets", v31 n11, November 2003, p. 29]

How meteorite age is estimated

Rubidium is the element most often used for dating meteorites. It is a relatively rare element, but its atomic size and chemistry are similar to geologically common elements like potassium and sodium. Small amounts of rubidium usually find their way into the crystal structure of minerals prevalent in meteorites.

About a quarter of all rubidium atoms are radioactive rubidium-87, which laboratory experiments show has a half-life of 47 billion years. An element's half-life is the time it takes for half of its original stock of radioactive atoms to decay.

The solar system is a lot younger than 47 billion years, so most of the original rubidium-87 still exists. Rubidium-87, which decays into strontium-86, is the only source of strontium-86 in the universe. When a meteorite forms, rubidium is locked into its crystal structure. As long as the rubidium and its strontium decay product don't go anywhere (and mineral crystals are great at holding onto atoms), you only need to measure the ratio of rubidium-87 to strontium-86 precisely. Because the half-life of rubidium-87 is well known, the ratio of these two isotopes will give you the date the meteorite formed.

The rubidium/strontium pair is just one of a number of isotopic systems used for dating ancient or relatively recent events. Other useful elements include potassium-40 (which has a half-life of 1.3 billion years), beryllium-10 (half-life of 1.5 million years), and carbon-14 (half-life of 5,700 years).

[Source: Dan Britt (University of Central Florida), "Ask Astro: Dating Rocks", Astronomy, v31 n11, November 2003, p. 68]

October 18, 2003

Neutrinos - ubiquitous ghosts of the universe; research competing for funding with fast breeder reactor program in Japan

Among the most obscure particles and waves in nature, neutrinos are sometimes called the ghosts of the universe because they have little or no mass, no electrical charge and tend not to interact with other matter. They stream from the sun and other stars.

Researchers believe there are so many of them - trillions pass through our bodies each second we stand in sunlight - that knowing more about them would expand our understanding of the universe.

Astrophysicist Masatoshi Koshiba, a professor emeritus at Tokyo University, won the 2002 Nobel Prize for his work on neutrinos. Using a neutrino detector, dubbed the Super-Kamiokande, Koshiba discovered neutrinos coming from distant supernova explosions. The chamber, the world's largest of its kind, sits inside an abandoned copper mine beneath a mountain in Kamioka, about 170 miles west of Japan's capital. He has proposed government funding of a $1.8-billion research facility, to allow researchers to shoot a beam of manmade neutrinos to the Super-Kamiokande. By comparing the beam leaving the Tokaimura facility with the one that reaches the Super-Kamiokande, they could determine how neutrinos behave.

Japan's Council for Science and Technology Policy, headed by Prime Minister Junichiro Koizumi, ranked the facility as the lowest priority for government spending next year, and recommended that it not be funded. Energy projects such as a prototype fast-breeder nuclear reactor should come first, the council said.

Exasperated, Koshiba called the decision "foolish." Scientists all over the world will "laugh at the council's decision", he was quoted as saying by the national Yomiuri newspaper. Koshiba has reportedly arranged to address the council on Tuesday, and is expected to push for construction to begin next year, as planned, in Tokaimura, about 70 miles northeast of Tokyo.

[Source: Kenji Hall (AP writer - Tokyo), "Japanese Nobel laureate blasts recommendation not to fund state-of-the-art neutrino reactor", Associated Press, October 18, 2003]

August 18, 2003

Russia plans Mars base, with nuclear plant

BBC reports that the first extraterrestrial nuclear plant may be operating on Mars by 2030, at a permanent Russian research camp. The article cites Deputy chief engineer of Red Star - a state scientific company closely affiliated with Russia's Nuclear Energy Ministry - as saying the station will be constructed in the mountainous areas of Mars, possibly in one of the canyons.

[Ref: Artyom Liss (BBC, Moscow), Russia plans Mars nuclear station, BBC News, August 18, 2003]

August 16, 2003 [updated March 28, 2004]

Scientific advances prompt reopening of Air Force nuclear aircraft program

For the past 40 years, little research has been done specifically relating to nuclear powered jet engines. Recent discoveries, in the field of controlled or triggered nuclear decay (Collins et al, 1999; McDaniel, undated), along with 40 years in the advancement of materials, airframe design, and jet engine development, have reinvigorated the possibility of running aircraft on nuclear power. Nuclear power could conceivably provide aircraft with compact heat sources allowing larger thrust levels than conventional chemical combustion systems can provide, as well as practically eliminating endurance limitations based on fuel requirements (Keirn, 1960).

If this new power source can be utilized to provide heat energy to jet engines, it could dramatically change flight envelopes, costs, and capabilities of aerospace vehicles.

High drag losses, which occur during low altitude flight, could be compensated by these propulsion systems; changing the fundamental way flight paths are developed. Flight times could be reduced by hours, if the need for refueling was eliminated. Thrust to weight values of these engines could allow for vertical or short runway takeoffs to become commonplace, imaginably eliminating the need for large runways.

While this idea has tremendous potential, research must begin in an orderly and progressive way. Basic systems need to be designed and suitable first-step applications need to be developed. Research into replacing a combustion section of a turbojet engine, with a triggered isomer heat exchanger represented the start of this process, by showing that the concept was feasible (Hartsfield, 2001)...

Triggered Isomer (TI) [Physics Research] Program...

While research in radioisotope decay is not new, the ability to trigger a large release of this energy on demand is a recent discovery. The Directed Energy Directorate of the Air Force Research Laboratory has been working in this field for the past several years and a joint Department of Defense and Department of Energy effort has been created to pursue this technology (McDaniel, undated).

In 1998, University of Texas researchers led by Dr. Carl Collins were able to trigger significantly increased energy decay in a Hafnium isomer sample using a dental X-ray unit (Collins et al, 1999). The decay of the Hafnium in this case was a cascade of Gamma rays and X-rays of varying energy levels. Some of the X-rays in the cascade were similar in power and wavelength to the triggering X-rays from the dental device. If a means of reflecting the X-rays can be incorporated into a reactor, a chain reaction might be possible. This would allow for a near instantaneous decay and the creation of a controllable power source. (McDaniel, undated)

This very compact power source could provide large amounts of heat. Aircraft and spacecraft could utilize this new power source, if it was made part of a high thrust-to-weight heat exchanger propulsion system. Rockets, or even jet engines, could be modified or redesigned to utilize this propulsion system in order to gain specific impulse or endurance values that are not possible with conventional combustion techniques. An important factor that separates this triggered isomer reaction from fission reactions is that the radiation output is significantly less. Normal fission reactions, that have been proposed to drive rockets and jet engines, produce not only gamma radiation but also release neutrons and fission products, which would significantly increase shielding requirements, perhaps offsetting the weight reductions from the compact heat source. Gamma radiation, the only significant radiation product from TI reactions, while still dangerous, requires less shielding (McDaniel, undated).

One of the studies commissioned by the triggered isomer program was a feasibility study of replacing outright a combustion section of an off-the-shelf turbojet engine with a solid-state heat exchanger (Air Combat Command, 2000). This study, utilizing current computational fluid dynamics and heat transfer methods, was able to show that a J-57 turbojet engine could provide equal thrust with a combustor or a heat exchanger at sea level static conditions. Several conclusions were made in this study.

The first was that if the heat generation rate could be controlled and that the heat exchanger material itself was made from the isomer, several different configurations could be utilized to be suitable replacements for the combustor. Issues of manufacturing and development of the triggering and control system were left as areas for further research.

The second conclusion was that the ability of this heat exchanger to supply sufficient heating to the flow increases with higher altitudes. Due to the thermodynamics involved in engine performance at higher altitudes, heating requirements also drop off. This results in lower heat generation rates and reduced radiation output, thereby extending component lifetime.

The final conclusion was that this heating source would greatly increase aircraft endurance and Òcould drastically change the operating paradigms for many missions.Ó (Hartsfield, 2001) Heat exchanger geometry could be optimized for specific aircraft and missions that would result in even more efficient turbojet engines.

[Applications]

The research done so far on TI reactor systems shows that it has the potential of being an enabling technology for aerospace propulsion (Hartsfield, 2001). Possible applications for atmospheric flight are numerous, including: highly maneuverable fighter/attack aircraft; long range cargo or passenger flight; long endurance intelligence, surveillance, and reconnaissance (ISR) platforms; long endurance communication relay platforms; and very long range cruise missiles. Rocket propulsion could also be enhanced resulting in significantly lower launch costs and shorter trip times to other planets.

Of the possible aircraft missions, the benefits of extended endurance impact heavily on the ISR platforms... Many ISR aircraft fly at high altitudes to avoid surface threats and to allow larger area coverage. Slow flight allows for longer loiter times over the areas of interest. Both of these aspects of ISR platforms lower required thrust to maintain flight and make this mission ripe for TIHE application.

Due to radiation concerns, the first application of a TIHE powered jet engine will likely be on Unmanned Aerial Vehicles. In the case of HALE missions used in the ISR vehicles, this is advantageous since life support requirements become prohibitive very quickly due to mission duration and altitude.

With the selection of the HALE-UAV mission, it is important to note that such an aircraft has been recently produced and is flying operational missions. The Global Hawk aircraft, built by Northrop-Grumman for the United States Air Force, is the first High Altitude ISR UAV in production. The Global Hawk program started in 1994 as an Advanced Concept Technology Demonstrator and is currently completing its engineering, manufacturing and development phase (Air Combat Command, 2000). It has successfully been tested in action as part of the Department of DefenseÕs Operation Enduring Freedom over Afghanistan.

Jane's suggests that a more advanced unmanned vehicle, such as a twin-engine aircraft, will be favored for TI program over the Global Hawk (Jane's, 2003).

Not a slam dunk

Physicists from the Lawrence Livermore National Laboratory, in collaboration with scientists at Los Alamos and Argonne national laboratories, have new results that strongly contradict recent reports claiming an accelerated emission of gamma rays from the nuclear isomer 31-yr. hafnium-178, and the opportunity for a controlled release of energy (Livermore, 2001). The triggering source in the original experiment was a dental X-ray machine.

Using the Advanced Photon Source at Argonne, which has more than 100,000 times higher X-ray intensity than the dental X-ray machine used in the original experiment, and a sample of isomeric Hf-178 fabricated at Los Alamos, the team of physicists expected to see an enormous signal indicating a controlled release of energy stored in the long lived nuclear excited state. However, the scientists observed no such signal and established an upper limit consistent with nuclear science and orders of magnitude below previous reports.

The results measured by the collaboration including John A. Becker, Andreas Kraemer, Dennis McNabb and Tzu Fang Wang of LLNL; Joseph Banar, Geoffrey Miller, Laurence Pangault , Robert Rundberg and Jerry Wilhelmy of LANL; Irshad Ahmad, Frank Moore, Donald Gemmell, John Schiffer of the Argonne Physics Division; and Ali Mashayekhi and Sarvjit Shastri of the Advanced Photon Source at Argonne, appear in the August 13 edition of Physical Review Letters.

Nuclear isomers include excited states of nuclei that electromagnetically decay slowly enough for energy storage. However, the emitted gamma rays of the isomer decay come in a burst. Controlled triggering of the isomer decay allows stored energy to be released on demand, and nuclear isomers represent a potential stand-alone energy source. Barriers to developing a practical energy source are triggering and production. The tri-lab team decided to validate the earlier experiment and the conclusion of previous researchers: energy can be released in a controlled application that could be developed into a gamma ray laser.

The team set out to verify previous findings that stated a nuclear isomer, (hafnium) Hf-178, which has a half life of 31 years, is able to release a controlled amount of energy (decay quicker) when tickled with dental machine X-rays. However, when the team turned the APS X-ray beam onto the sample of 31-yr. Hf-178, no detectable increase of the isomer decay occurred. In other words, the X-ray irradiation did not decrease the time it takes for hafnium to decay; a result that Becker and the team claim is consistent with nuclear physics.

"We were trying for a verification of their (the previous scientistsÕ) claims," Becker said. "Because the previous findings were so significant, our team felt the experiment deserved to be repeated and verified. Instead, we vigorously disagree with earlier results through direct experimental measurement. The earlier reports were also very unlikely, in any case, on very general physics arguments."

The new research shows that the practicality of this scheme of controlled release of energy and its application to gamma-ray lasers has fallen back into an interesting speculation. The experiment is a considerable contribution to the physics community. It has been selected as one of the best five works done at one of the Advanced Photon Source sectors during 2000.

The Department of EnergyÕs Nuclear Energy Research Initiative and the Office of Science/Nuclear Physics Division funded the research.

Prof. Collins points out some very good reasons why the Argonne-Livermore-Los Alamos team was unable to reproduce his results: In its first attempt, the Argonne group had set its X-ray at the wrong energy level. In his first article, Collins didn't specify the exact energy level that triggered the hafnium, he said, because his group learned what it was only after repeating the experiment at an advanced X-ray source in Japan (Weinberger, 2004). Collins said the failure in Becker et al's second experiment a year later was the result of other differences in the design of the Argonne experiment. One of the most significant differences, he said, was that the radiation detectors were "blind" to precisely the energy level of gamma-ray emissions present when the isomer was triggered -- totally blind at the energy which provides the signature of Hf-isomer triggering. This finding and full report of the confirmatory SPring-8 experiments (using monochromatic X-rays from the World's most advanced synchrotron radiation source) were published in the journal Laser Physics in February 2004 (Collins et al., 2004). In a recent interview, Prof. Collins described the members of the Argonne group as "failures," who were unfamiliar with the literature on triggering and inexperienced in the field (Weinberger, 2004). For example, the Argonne team essentially used their multi-hundred-million-dollar synchrotron to emulate the $1500 dental x-ray machine Collins et al. used in their first experiments, instead of taking advantage of their machine's ability to produce monochromatic x-rays.

Prof. Collins notes "the obligations of the scientific method ... require professionals to follow short "Letter-type" announcements of contention with a full article revealing all aspects of calibration, data acquisition, analysis and conclusions. After we published our Phys. Rev. Lett., we published the full article in Phys. Rev. C, 61,054305 (2000). After we published our Europhys. Lett. article, we published the full exposition of what we accomplished with monochromatic X-rays from SPring-8 in Japan in Laser Physics. In contrast, after the first Letter-type publication from the Argonne Group, they did NOT publish any longer explanation of what they actually did. After their second Letter publication, they did NOT meet their obligation to publish a disclosure of what they actually did." (Collins, e-mail to nuclear.com, February 2004). "Another of the obligations of Professionalism", Collins told nuclear.com, "is self-criticism. The traditional mechanism is interaction in open discussion, challenge and reply, at professional society meetings. In 2003 we presented (and defended) our proof of Hf-isomer triggering at Malmo in June, Hamburg in August, and Cape Town in October. No one from the Argonne Team has even participated in any of these open meetings either to engage us or to learn from criticism of their own efforts."

Isomer Research: Energy Release Validation, Production, and Applications

Here's how DOE's most recent annual Nuclear Energy Research Initiative report describes the mixed results of research, and the approaches researchers are taking (DOE, 2003):

Primary Investigator: John A. Becker, Lawrence Livermore National Laboratory (LLNL)

Collaborators: Los Alamos National Laboratory (LANL); Argonne National Laboratory (ANL)

Project Number: 00-123

Project Start Date: April 2000

Project End Date: September 2003

Research Objectives

The goal of this applied nuclear isomer research program is the search for, discovery of, and practical application of a new type of high energy density material (HEDM). Nuclear isomers could yield an energy source with a specific energy as much as a hundred thousand times as great as that of chemical fuels. There would be enormous payoffs to the Department of Energy and to the country as a whole if such energy sources could be identified and adapted to a range of civilian and defense applications. Despite the potential payoff, efforts in applied isomer research have been rather limited and sporadic. Basic research on nuclear isomers dates back to their discovery in 1935 with an occasional hint of further progress since then to tantalize interest in HEDM. In most cases, these hints were refuted following careful examination by other groups.

The isomer research area is rich with possibilities and several areas were prioritized as likely to be the most rewarding and fruitful for initial experimental and theoretical investigation. These areas bear directly on important issues: Can the energy stored in nuclear isomers be released on demand? Is the size of the atomic-nuclear mixing matrix element large enough to be useful? Under what circumstances? Can quantal collective release of isomeric energy be initiated from a Mšssbauer crystal? What is the precise energy of the 3.5 eV level in 229m Th?

Specific experiments have been targeted to provided some answers:

* X-ray induced decay of isomeric Hf (178m2 Hf) with a sensitivity 10E5 times that of recent work

* NEET: A measurement of the atomic-nuclear mixing matrix element in 189 Os

* Stimulated emission in isomeric Te (125m Te)

* Superradiance in isomeric Nb (93m Nb)

* Energy and lifetime of the 229m Th isomeric level at 3.5 eV

* TEEN: Nuclear isomer energy release in isomeric Hf 178m2 Hf

Research Progress

Triggered decay of a nuclear isomer is clearly one requirement for usefulness of isomers as an energy source. Research in the past two-years focused on the question, "What is the cross section for keV X-ray induced decay of the 31-y isomer in the nucleus 178 Hf with nuclear excitation energy 2.4 MeV?" The question is relevant because induced decay had been reported in isomeric Hf 178 Hf with an integrated cross section of 10 -21 cm 2 -keV, orders of magnitude greater than nuclear cross sections (Collins et al., 1999, Phys. Rev. Lett. 82, 695, and Collins et al., 2002, Europhys. Lett. 57, 677). This team (Ahmad et al., 2001, Phys. Rev. Lett. 87, 072503) has reported an upper limit approximately 5 orders of magnitude below that of Collins (1999) for Ex >20 keV (see Figure 1). The 2002 report of Collins et al., claims that the induced decay occurs at lower X-ray energies than they previously reported (near 10 keV). This work was done at the Japanese 3rd Generation Synchrotron light source, SPring-8.

The collaborative team from ANL, LANL, and LLNL believes this result is also specious. They designed and fielded a second experiment at the ANL Advanced Photon Source (APS) in 2002 with an experimental arrangement optimized for low energy X-ray bombardment, but still taking advantage of the intense "white" beam as opposed to utilizing an monochromatic beam. This arrangement permits more photons incident on the target than in an experiment with a quasi-monoenergetic beam, without "holes" in the incident X-ray flux. Thin Hf targets enriched in the 31-y isomer mounted on Be disks were used in the experiment. On-line analysis suggests that the cross section s x-ray for induced X-ray emission is less than 10E-27 cm2-keV at the 5 s limit for Ex >6.5 keV. This result is orders of magnitude below claims made any positive published claims.

Planned Activities

Work will move on from the isomeric Hf issue to attack the physics of nuclear isomers relevant to their use as an energy source. The particular focus will be on the following areas:

* Documentation of the experiments on the X-ray induced enhanced decay of isomeric 178 Hf, with a focus on low incident X-ray energies. Controversial experimental reports continue to circulate in the literature and in the community of scientists working in isomer physics.

Figure 1. The graphs illustrate the decay scheme of 31-y isomeric Hf-178. The cross-section results of Ahmad et al. (2002) and Collins et al. (2001) are shown on the right-hand side. The green line shows the cross section expected for E1 absorption to a level at E photon with strength 0.01 W.u. as a function of E photon . The strength of the photon absorption (0.01 times a single particle unit) represents a reasonable upper limit to the transition strength ...

* NEET, Nuclear Excitation by Electronic Transition, in 189 Os. The process has been demonstrated in 197 Au, in a recent synchrotron experiment in Japan. The matrix element is similar to the (inverse) internal conversion matrix element. Important conditions for NEET to compete with real photon emission will include an energy overlap of the atomic and nuclear states, and a common multipolarity of the atomic and nuclear transitions. An experiment is being developed to prepare ionized atomic 189Os by bombardment with a variable energy electron beam in an electron beam ion trap (EBIT) and to pump a nuclear state in 189 Os at 216.6 keV. The energy of the electron beam is carefully controlled and tuned so that the sum of the energies of the bombarding electron beam and the L-shell ionized 189 Os (a free-bound transition) add up to the excitation of the nuclear 189 Os level at 216.6 keV. Trapped ions are periodically gathered up and counted. The signal is the energy and decay rate of the JTI=9/2', Ex=30.814 keV, t1/2=5.7 h state, populated in the decay of the 216.6-keV nuclear state. The experiment is sited at LLNL's EBIT facility.

* Stimulated emission of isomeric 125m Te. Large quantities of isomeric 125m Te enable an experiment to demonstrate stimulated emission of photons from nuclear isomers. The signal is the enhancement of time-correlated photons observed in a solid state detector located on the axis of a rod-shaped Mšssbauer source. The Khlopin Radium Institute in St. Petersburg, Russia, has developed a program (under ISTC auspices) to extract 125 Sb from spent nuclear fuel as a generator of 20 percent 125m Te. The content of 125 Sb in 20 to 50 GW-day fuel after a four-to six-year cooldown is 3 curies per kilogram of uranium. This is a larger source of isomeric 125m Te than previously available. A 0.5-cm long source of magnesium tellurate containing 20 percent 125m Te would produce a stimulated gamma ray at the rate of 3.9 x 10 -3 /sec, observable over accidental coincidence rate 8 x 10 -4 /sec. If successful, this would be the first observation of stimulated emission of gamma rays. In order to achieve gain, Borrman channeling or some other effect requiring single crystals would be necessary to reduce the attenuation of 109-keV gamma rays. The Khlopin Radium Institute has been contacted to determine the availability and schedule the acquisition of 125m Te. Once the source is acquired, a magnesium tellurate Mšssbauer source will be made, and the experiment fielded. The needed apparatus to observe time-correlated photon emission exists in the laboratory at Los Alamos and can be set up within a few months.

* Superradiance in isomeric 93m Nb. Superradiance is an effect discovered by Robert Dicke in the 1950's that results in an enormous broadening of the photon channel through the cooperation of an ensemble of quantum excited states. The possibility of nuclear superradiance was recognized for Mšssbauer crystals in the 196 0s. One of the most likely candidates for exhibiting nuclear superradiance is 93m Nb. The observation of enhanced photon emission would be the first evidence of the broadening of the photon channel width necessary to exploit the stored nuclear energy in a nuclear isomer. Molybdenum isotope production targets in the Medical Isotope Program are a source of 93m Nb at LANSCE. Approximately, 300 grams of molybdenum was processed last year to extract 0.5 milligrams of niobium. This brings the total inventory at LANL to 3 milligrams. The inventory of 93m Nb is now 0.2 milligrams. An attempt will be made to create a single crystal containing a high enrichment of 93m Nb from the present stock. The synthesis of potassium heptaflouroniobate crystals is being attempted from Nb-HF-KF aqueous solution. This method is being examined as a possible method for producing single crystals containing 93m Nb. A search will be made for enhanced photon emission along nuclear Bragg angles following successful crystal growth.

* 229Th ground state doublet (3.5 eV). What is the energy of the first excited state of 229Th near 3.5 eV? The uncommonly low energy of the ground state doublet would allow a laboratory isomer that could be manipulated by a laser. There are also potential applications as a radionuclide thermal source (RTG). Researchers at LLNL and LANL are working with colleagues at ANL to establish the feasibility of such an experiment, taking advantage of unique facilities at ANL.

References:

Air Combat Command. ÒRQ-4 Global Hawk Unmanned Aerial VehicleÓ Fact Sheet. Langley AFB, VA. 2000 [as cited by Hamilton]

Collins, C.B., F. Davanloo, M.C. Iosif, R. Dussart, J.M. Hicks, S.A. Karamian, C.A. Ur, I.I. Popescu, V.I. Kirischuk, J.J. Carroll, H.E. Roberts, P. McDaniel, and C.E. Crist. ÒAccelerated Emission of Gamma Rays from the 31-yr Isomer of 178Hf Induced by X-Ray Irradiation,Ó Physical Review Letters, 82-695-698 (January 1999) [as cited by Hamilton]

Collins, C.B. et al., "Accelerated Decay of the 31-yr Isomer of Hf-178 Induced by Low-Energy Photons and Electrons", Laser Physics 14(2):154-165, 2004

DOE, "Nuclear Energy Research Initiative", NERI Ñ 2002 Annual Report, January 2003, pp. 263-5

Hamilton, Christopher E. (Captain, USAF), Masters Thesis, "Design Study of Triggered Isomer Heat Exchanger-Combustion Hybrid Jet Engine for High Altitude Flight", AFIT/GAE/ENY/02-6 (Department of the Air Force, Air University, Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio), March 2002, pp. 1-2, 5-9

Livermore Lab press release NR-01-08-05, "Physicists Challenge Reports of Accelerated Decay of Nuclear Excited State", August 13, 2001

Hartsfield, C. R., ÒAnalysis of the Application of a Triggered Isomer Heat Exchanger as a Replacement for the Combustion Chamber in an Off-the-Shelf Turbojet.Ó MS Thesis, AFIT/GAE/ENY/01M-04. School of Engineering and Management, Air Force Institute of Technology (AU), Wright-Patterson AFB OH, March 2001 [as cited by Hamilton]

Jane's Information Group, "Flight of the Hummingbird: long-endurance UAVs with a difference", International Defense Review, June 1, 2003

Keirn, Donald J. ÒThe USAF Nuclear Propulsion ProgramsÓ in Nuclear Flight: The United States Air Force Programs for Atomic Jets, Missiles, and Rockets. Ed. Kenneth F Gantz. New York: Duell, Sloan, and Pearce, 1960 [as cited by Hamilton]

McDaniel, Pat. ÒTriggered Isomer Research Program: Propulsion Aspects.Ó Memorandum from AFRL/DEPA, undated [as cited by Hamilton]

Weinberger, Sharon. "Scary Things Come in Small Packages", The Washington Post Magazine, March 28, 2004, pp. 14-19, 27-32

For more info about the 1940s-1960s fission aircraft R&D, see nuclear.com's history section.

May 19, 2003

Peaceful nuclear explosion pondered

The current issue of the journal Nature describes a plan for sending a probe into the earth's core, the outer edge of which is some 1,790 miles below the surface. Man's deepest drills have gone only a measly 6 miles. Cal Tech planetary geologist David J. Stevenson is the imaginative thinker. He proposes using an as-yet undesigned grapefruit-sized probe that can withstand the intense calculated pressure. The probe would be transported by the flow of 220 million pounds of molten iron injected into a crack in the crust created by a nuclear blast.

"Since British geologist Richard Oldham first presented evidence for the core's existence in 1906, scientists have been struggling to probe its mysteries. They're fairly sure Earth contains two cores - a liquid outer shell surrounding a solid inner center. By studying seismic waves, they know the core is composed primarily of iron. The big question: What else is down there? If they knew what other elements swirl in the core's molten stew, Buffet says, scientists could better answer questions ranging from what drives the tectonic plates to how Earth formed in the first place.

"While he expects ribbing for his far-out proposal, the Caltech scientist says he hopes it will provoke geologists to get serious about finding ways to go deeper. 'This is really Jules Verne stuff,' Buffet concedes, but 'it might be something worth thinking about.'"

[Source: Michael Stroh (Sun Staff), "Sending a probe to Earth's core", Baltimore Sun, May 19, 2003]