May 10th, 2008
A new career: isotope designer
According to a Michigan State University (MSU) news release, ‘Made-to-order isotopes hold promise on science’s frontier,’ nuclear physicists can now start a new career as isotope designers. These scientists can build specific rare isotopes to solve scientific problems and open doors to new technologies. The lead researcher says this approach has already given us the Positron Emission Tomography (PET) scan technology. He’s now going further, saying that he wants to build objects 100,000 times smaller than the atomic nucleus. He calls this ‘femtotechnology.’ Fascinating, but read more…
This research work has been led by Bradley Sherrill, a University Distinguished Professor of physics and associate director for research at the National Superconducting Cyclotron Laboratory (NSCL) at MSU. You can see above the layout of the Superconducting Source for Ions (SuSI) under development at NSCL. (Credit: MSU) Here is a link to a larger version of this illustration.
And a mechanical drawing of the Radio Frequency Fragment Separator (RFFS) currently under construction at the NSCL is shown above. (Credit: MSU) “The ions experience a transverse RF electric field between the two plates held by the resonator wedges centered in the tank. The two coarse tuners, the fine tuner (bottom left), and the RF coupler (top right) are also shown.” Here is a link to a larger version of this figure.
Here is a short excerpt from the MSU news release. “Sherrill said this type of basic science — science to examine the core nature of the elements of life — holds its own gold mine of potential. He offers up PET scans — short for positron emission tomography — as an example of the payoff associated with pushing the bounds of accelerator science to study new specific isotopes. To create PET scans, scientists first had to create an isotope with a specific radioactivity that decayed quickly enough and safely enough to inject in the body.”
The latest work from Sherrill has been published in Science under the name “Designer Atomic Nuclei” (Volume 320, Issue 5877, Pages 751-752, May 9, 2008). Here is a link to a very short summary. “New isotopes with unusual decay modes or number of neutrons are having impacts in areas ranging from astrophysics to medicine.” Fortunately, MSU provides additional details. “Sherrill said that aggressively pursuing rare isotope research is a national imperative. ‘These are isotopes that are not easy to produce. That’s the frontier we’re working on,’ Sherrill writes. ‘A wider range of available isotopes should benefit the fields of biomedicine (by producing an expanded portfolio of radioisotopes), international security (by providing the technical underpinning to nuclear forensics specialists) and nuclear energy (by leading to better understanding of the sort of nuclear reactions that will power cleaner, next-generation reactors).’”
Here are some quotes picked from Sherrill’s home page. “The rise of nanotechnology is garnering much attention for its ability to construct objects out of individual atoms and molecules, at a scale roughly a billion times smaller than the objects we encounter in our everyday lives. In parallel to nanotechnology’s achievements; my research is to develop the capacity to construct objects on an even more minute scale, that of the atomic nucleus 100,000 times smaller. It is probably to best to describe this as femtotechnology.”
He also briefly described the techniques he’s using. “The approach that I have helped develop for production of new isotopes is called in-flight separation; where a heavy ion, such as a uranium nucleus, is broken up at high energy, producing a cocktail beam of fragments that are filtered by a downstream system called a fragment separator. The efficiency of this technique can be nearly 100%.”
Finally, Sherrill has also been instrumental in the design of the Isotope Science Facility (ISF). For more information, here is a link to a 415-page design paper of the future facility (PDF format, 415 pages, 33.82 MB). The illustrations shown above can respectively be found on pages 180 and 54.
Sources: Sue Nichols, MSU Today, Michigan State University, May 9, 2008; and various websites
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