Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High in Sodium: Highly Charged Tungsten Ions May Diagnose Fusion Energy Reactors

10.09.2009
Just as health-food manufacturers work on developing the best possible sodium substitutes for low-salt diets, physicists at the National Institute of Standards and Technology (NIST) have acquired new knowledge on a promising sodium alternative of their own. Sodium-like tungsten ions could pepper—and conveniently monitor—the hot plasma soup inside fusion energy devices, potential sources of abundant, clean power.

Tungsten—having the highest melting point of any metal—will be used in some high-strength structural components in the experimental ITER fusion reactor under construction in France (see “NIST Light Source Illuminates Fusion Power Diagnostics,” NIST Tech Beat, Oct. 11, 2007.).

When ITER cooks up its hot, dense fusion plasma, it could erode trace amounts of tungsten from its structures and strip away many of its electrons in the process. When 63 of tungsten’s 74 electrons are removed, it becomes chemically analogous to sodium atoms, which have 11 electrons as well.

Ordinary sodium gas radiates bright yellow-orange light, which has proven useful for everything from mundane streetlamps to exotic atom lasers. Sodium radiates approximately 99 percent of its visible light in two shades of orange, which scientists have termed the “D” spectral lines.

Sodium-like tungsten ions emit intense light in analogous “D” spectral lines, but they are at far higher energy levels than sodium, and so are shifted out of the visible spectrum to the extreme ultraviolet. Measuring the wavelengths and relative intensities of lines in the spectrum of light released by a population of tungsten ions in the plasma can provide information about the fusion plasma conditions, such as its temperature, density and magnetic fields. Yet it has been challenging to measure light in this portion of the electromagnetic spectrum.

NIST’s John Gillaspy and his colleagues have now provided the first measurement* of both “D” lines in sodium-like tungsten, confirming theoretical predictions of their energies and intensities. The NIST scientists further checked their knowledge by measuring the spectrum of light from other sodium-like ions of hafnium, tantalum and gold. The researchers used NIST’s electron beam ion trap (EBIT), which employs an electron beam to make, catch and study highly charged ions. To measure the spectra, they used an extreme ultraviolet (EUV) spectrometer, originally developed to study 13.5 nanometer wavelength light emitted from plasma sources for next-generation microelectronics applications, but they discovered they could push it to detect radiation as low as about 2 nanometers, where tungsten’s lower-wavelength “D” line resides. With this experimental knowledge of tungsten’s lines, researchers may now have a robust new ingredient for measuring fusion reactor conditions.

* J.D. Gillaspy, I.N. Draganic, Y. Ralchenko, J. Reader, J.N. Tan, J.M. Pomeroy and S.M. Brewer Measurement of the D-line doublet in high-Z highly charged sodiumlike ions. Physical Review A, Published online 8 July 2009. doi/10.1103/PhysRevA.80.010501.

Ben Stein | Newswise Science News
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

How gut bacteria can make us ill

18.01.2017 | Life Sciences

On track to heal leukaemia

18.01.2017 | Health and Medicine

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>