Innovative measurement technology: our planet is 'attractive' enough

July 21, 2005
Innovative measurement technology: our planet is 'attractive' enough

The Earth's magnetic field is strong enough for some kinds of analyses – this opens up new opportunities for carrying out examinations under difficult conditions.

Where x-rays no longer manage to see, magnets allow us to look inside. Patients know what that means: they lay down in the "tube" surrounded by an enormous electromagnet, the so-called MRI scanner. Such large pieces of equipment artificially create strong magnetic fields which enable doctors to take the pictures inside the patient's body which they need for their diagnosis. Now scientists from the Research Centre Jülich, a Helmholtz Association institution, and the RWTH Aachen University of Technology have extended the spectrum of magnetic field scanning. Because they have discovered that the Earth's natural magnetic field is strong enough for some examinations. And this closes a gap. Because it makes measurement with magnetic fields outdoors and under difficult conditions possible for the very first time. Although the applications will not initially be used in the field of medicine, they will make chemical analyses possible, such as when examining oil directly at source.

20,000 times weaker

When measuring with magnets, researchers use a natural phenomenon, namely that nuclei spin like a top, a property appropriately called "spin". The spin can be focused in a magnetic field to generate typical signals, so-called nuclear magnetic resonance. And it is this that opens up a wide range of insights for scientists into the composition and structure of matter. As a rule, they need very strong artificially produced magnetic fields for such work.

In experiments with the inert gas xenon, Helmholtz scientists were now able to show that under certain circumstances they can also use laser light to influence the spinning movement of the nuclei. In these cases, a weak magnetic field is already powerful enough for the analysis. Often, the Earth's natural magnetic field is even strong enough. By comparison, the Earth's magnetic field is around 20,000 times weaker than the field strengths used in these large pieces of equipment.

From inside Earth to solar wind

As Dr. Stephan Appelt from the Research Centre Jülich explains, a wide and diverse range of application options are conceivable. Besides chemical analyses outdoors and at hardly accessible places, geophysical examinations are also imaginable. "For example, we could survey the Earth's magnetic field with the highest precision," explains Appelt. "Furthermore, we could also look into the Earth, so to speak." That would make it possible to gain a better understanding of the earthquake risks along local fault lines, such as the San Andreas Fault in California or of volcanism. A third field of application would be in astrophysics. "Nuclear magnetic resonance in the Earth's magnetic field might also make it possible to measure the solar wind," believes Appelt. This wind is made up of particles ejected by the Sun and deviated by the Earth's magnetic field – the Northern Lights, "Aurora Borealis", are a side-effect of this.

Finally, another possible area of application is also the measurement of very weak magnetic fields inside patients. This would enable doctors to produce detailed pictures for the examination of diseased organs. "It's conceivable that contrast media could be used that contain xenon," explains Dr. Wolfgang Häsing from the Research Centre Jülich. "Patients could inhale these contrast media or they could be injected into them." All that would then be needed to carry out an MRI scan is a small additional magnetic field – the patient would be spared from the confines of the narrow tube. In fact, they would hardly notice the examination, because xenon is already used in medicine today, namely as an anaesthetic.

Source: Helmholtz-Gemeinschaft

Explore further: Jupiter's moon Europa

Related Stories

Jupiter's moon Europa

September 30, 2015

Jupiter's four largest moons – aka. the Galilean moons, consisting of Io, Europa, Ganymede and Callisto – are nothing if not fascinating. Ever since their discovery over four centuries ago, these moons have been a source ...

Titan helps unpuzzle decades-old plutonium perplexities

September 29, 2015

First produced in 1940, plutonium is one of the most electronically complicated elements on Earth—and because of its complexities, scientists have been struggling to prove the existence of its magnetic properties ever since.

NASA's BARREL team returns from Sweden

September 24, 2015

After seven balloon launches in the bright Arctic sun, the BARREL team has returned home from a 4-week campaign in Kiruna, Sweden, north of the Arctic Circle. Each research balloon observed emissions high in our atmosphere ...

Effort to map aurora borealis using Twitter

September 23, 2015

The past few months have been exciting for followers of the aurora borealis, commonly known as the Northern Lights. Sizable solar storms have produced spectacular auroras that have been visible in a much larger area than ...

Recommended for you

The dark side of Nobel prizewinning research

October 4, 2015

Think of the Nobel prizes and you think of groundbreaking research bettering mankind, but the awards have also honoured some quite unhumanitarian inventions such as chemical weapons, DDT and lobotomies.

Internet giants race to faster mobile news apps

October 4, 2015

US tech giants are turning to the news in their competition for mobile users, developing new, faster ways to deliver content, but the benefits for struggling media outlets remain unclear.

Trade in invasive plants is blossoming

October 3, 2015

Every day, hundreds of different plant species—many of them listed as invasive—are traded online worldwide on auction platforms. This exacerbates the problem of uncontrollable biological invasions.

Fusion reactors 'economically viable' say experts

October 2, 2015

Fusion reactors could become an economically viable means of generating electricity within a few decades, and policy makers should start planning to build them as a replacement for conventional nuclear power stations, according ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.