What's New at the Lab
There's a lot going on at the National MagLab. In this blog, we keep you up to date on the latest people, events and advances at our seven facilities.
Paul Dunk, a chemist in the MagLab's Ion Cyclotron Resonance Facility, has published a paper on so-called "nanocages" formed by combining graphite, a two-dimensional form of carbon, with different metals. The research, Transformation of doped graphite into cluster-encapsulated fullerene cages, appeared this week in Nature Communications.
For the research, Dunk and his collaborators created metallofullerenes, molecules that consist of a ball-like carbon structure that encompasses several atoms inside of it — hence the term "nanocage."
Dunk and his colleagues tested theories of how these compounds form by looking for hypothesized intermediate molecules between the original reactants and end products. They demonstrated that, unlike what many scientists believed, the cages do not shrink from or break off of larger globs of carbon, but rather nucleate around the metal, carbon atom by carbon atom.
The findings could help in the future development of nanocage-related technologies ranging from new light-based electronics to molecular electronics.
Dunk's research was done in collaboration with scientists at the Universitat Rovira i Virgili in Spain and the University of Texas at El Paso.
Read more about this research in the MagLab's fields magazine.
Image of nanocages by Paul Dunk/Caroline McNiel.
These top-notch magnets require a top-notch infrastructure. So later this year, lab staff will install a new heat exchanger to keep up with the demands of its boundary-pushing instruments.
"We're trying to upgrade everything as the lab upgrades," explained plant engineer Tra Hunter. "The magnets are getting bigger and requiring more cooling water."
Magnets in the lab's DC Field Facility are powered by as much as 32 megawatts (MW) of electricity each and generate the heat to match. A complex array of pipes, chillers, heat exchangers, chilled water storage tanks and cooling towers keeps the instruments from overheating by flushing them with thousands of gallons of cold, de-ionized water a minute.
The new 35,000-pound heat exchanger features a stack of nearly 600 8x4-feet stainless steel plates. Warm water from the magnets flows in through one pipe and zigzags through alternating plates; chilled water flows in another pipe, snaking its way through the second set of plates. The cooled water picks up heat from the magnet water and carries it away.
"It's basically transferring 36 MW of heat from the magnet cooling water loop and transferring that to the chilled water loop," Hunter explained.
The $130,000 instrument is one of several end-of-year upgrades to the chilling system that will also include larger pipes and new water filters. It will help the plant run more efficiently and, as one of two similar units, and help ensure chilled water for the more than 1,700 users who come to perform research on the lab’s world–record magnets each year.
Story by Kristen Coyne. Photo by Stephen Bilenky.
MagLab-affiliated researcher and FAMU-FSU College of Engineering faculty member Subramanian Ramakrishnan has received a prestigious Centers of Research Excellence in Science and Technology (CREST) grant from the National Science Foundation.
The five-year, $4.9 million grant will establish the Center for Complex Materials Design for Multidimensional Additive Processing (known as the CoManD Center). This new center will tap into expertise of researchers at Florida A&M Univeristy (FAMU), the College of Engineering and the National MagLab to advance manufacturing at the micrometer scale for biological, aerospace and energy applications.
In association with the National MagLab, Ramakrishnan will direct the center’s first project, which focuses on developing nanostructured lightweight materials for shielding and sensing applications. Industrial Engineering Professor Tarik Dickens will direct the center’s second subproject, which will consist of developing materials/devices for energy applications in association with the High Performance Materials Institute. Pharmaceutics Professor Mandip Singh Sachdeva will direct the center’s third subproject, which includes developing materials/devices for biological applications such as a 3D printed tumor biosystem on a chip.
"The uniqueness of this award is the synergy between universities, national labs and defense labs," Ramakrishnan explained.
In addition to research, the grant will help support undergraduate courses based on the fundamentals of self-assembly, nanoparticle synthesis and characterization, additive manufacturing, nanomaterials in biology, and nanoparticles in medicine. The courses will be developed and offered to FAMU students. Also, a laboratory course in materials will be offered to graduate and undergraduate students involved in materials research. The center will work to produce 15 doctorate students, directly impact 40 undergraduates, and influence 100 graduate students and 300 additional undergraduates through collaborations and coursework.
Story by Kristin Roberts.
Scientists are welcoming a new MRI machine at the National MagLab that provides the best spatial resolution available for human imaging, making it a powerful tool for nationwide, multi-site health research.
Manufactured by Siemens, the state-of-the-art, whole-body scanner is powered by a 3-tesla magnet (tesla is a unit of magnetic field strength). But it's not the machine’s main magnetic field — on a par with many hospital MRIs — that makes the instrument special. Rather, the unit features the most powerful gradient magnet fields available, which help generate very sharp images of very tiny anatomical structures.
“Gradients provide the high spatial resolution in MRI, and with the new system we get the localization we need for small structures,” said Joanna Long, director of the MagLab's Advanced Magnetic Resonance Imaging and Spectroscopy (AMRIS) facility at the University of Florida, where the new instrument is located.
For anyone who has been inside an MRI machine, the gradient magnetic fields are responsible for that unpleasant racket you hear; technicians trigger them to target different areas of the body. But they also help generate more precise images – in this case, around a millimeter in resolution, allowing scientists to see bundles of neurons inside the brain. (Learn more about how MRI machines work).
As one of a number of similar machines recently installed around the country, the new system will enable researchers working at AMRIS to participate in large-scale, multi-site health studies. For example, some AMRIS researchers are using the machine as part of a years-long study to track brain cognitive development in adolescents. Others will use it for research on Alzheimer’s and Parkinson’s disorders. Glenn Walter, an associate professor in physiology and functional genomics at the University of Florida, is using it to develop MRI techniques to assess how effective drugs are at treating muscular dystrophy, a less invasive approach than muscle biopsy.
By allowing MagLab users to participate in such longitudinal studies, the $3 million system will yield high research dividends. “It's a really good example of how the magnetic resonance research program at the MagLab can leverage something bigger,” Long said.
To celebrate a trio of recent upgrades, including the new MRI machine, added dynamic nuclear polarization capabilities, and a new console for the 11-tesla MRI/S system, AMRIS hosted a reception and symposium this week.
Text by Kristen Coyne; Image courtesy of AMRIS.
The National MagLab is known for its world-record magnets, like the 45-tesla hybrid magnet — the strongest on the planet.
But for some physics experiments, there’s another critical ingredient to good results: extremely cold temperatures. And thanks to a fancy cooling machine called the portable dilution refrigerator (dil fridge, or PDF, for short), the National MagLab is able to offer a potent combination of experimental conditions unique in the world.
This month, the PDF is set up in one of our magnets, allowing scientists to observe what happens to materials when they are under magnetic fields as high as 35 teslas and at temperatures just above absolute zero (-459 degrees Fahrenheit or -273 degrees Celsius).
Leveraging the cooling power of liquid helium, the PDF removes thermal energy from the materials the researchers are studying. “This allows scientists to see the physical properties of materials, such as quantized energy states and quantum phase transitions,” said MagLab physicist Hongwoo Baek, who is in charge of the apparatus.
“If you add magnetic fields,” Baek continued, “you will also see magnetic properties, such as magnetic phase transitions, and other detailed electronic features that are not normally shown at zero field, that can be utilized in future electronics and applications.”
The National MagLab is the only place scientists can throw that one-two punch of very high fields and very low temperatures.
“Many institutes have 20-millikelvin dilution refrigerators, and some have 35-tesla magnets,” said Baek, “but none of them can provide the experimental platform with 20 millikelvin and 35- to 45-tesla magnet together.”
The MagLab system offers another big bonus: it can rotate samples within the magnetic field without generating much heat, allowing the sample to align to the magnetic field and stay nice and cold.
Over the next few weeks, research groups from Rice University, Princeton University, Northwestern University, the University of Cambridge and the MagLab will conduct experiments in this unique setup, studying phenomena ranging from the fractional quantum Hall states to exotic magnetic phase transitions of various materials.
Find out more ...
Text by Kristen Coyne. Photo by Stephen Bilenky.