Superfluids are one of many twentieth century’s most fascinating and vital discoveries. Their examine is the idea of Nobel Prize-winning work, and so they maintain promise for higher electrical energy transmission and should even assist reply the secrets and techniques of the universe with their mysterious “quantum fluid” properties.
Wei Guo, an affiliate professor of mechanical engineering on the FAMU-FSU Faculty of Engineering, is the principal investigator for a brand new grant funded by the National Science Foundation to research the dynamics of superfluids. Superfluids exist at low sufficient temperatures that quantum mechanics — which offers with physics on the size of atoms or subatomic particles — govern their habits. The analysis will advance our understanding of quantum turbulence utilizing three-dimensional circulation visualization applied sciences.
The grant, which begins in summer season 2021, is funded at $521,000 for 3 years.
Earlier analysis from Takeshi Egami of Oak Ridge National Laboratory confirmed that when helium fuel is cooled to excessive temperatures, it turns into a liquid and behaves oddly — it could circulation with out friction as a superfluid. Absence of friction means no lack of kinetic vitality within the fluid.
Guo and his group of graduate college students and post-doctoral researchers will use multidimensional circulation visualization to additional examine the superfluid and its distinctive properties.
“We’ll cool helium to its superfluid state,” Guo stated. “Then we’ll develop and use superior 3D circulation visualization techniques to check phenomenon associated to turbulence on this quantum fluid.”
The helium superfluid, often called He II, is of curiosity to scientists as a result of it permits them to check the quantum world with visible reference. It additionally has a superior means to chill scientific devices resembling particle colliders, superconducting magnets and satellites. One situation that may impair its effectivity is turbulence. When the warmth switch is comparatively sturdy, turbulence can seem spontaneously, and the researchers wish to perceive this higher.
Vortex tubes are one other phenomenon present in He II that the researchers will discover. When superfluid helium is stirred, vortex tubes — like tiny tornadoes with hole cores — can seem. Finding out their dynamics might assist us perceive numerous bodily techniques that can not be studied in a laboratory, resembling superfluid neutron stars and even cosmic strings created within the early universe.
“We all know that the simplest technique to check vortex motions is to picture the vortices,” Guo stated. “We purpose to implement 3D imaging circulation visualization applied sciences to unravel a number of difficult issues within the quantum turbulence subject.”
Guo’s group will work on two tasks. Within the first undertaking, the researchers plan to assemble a stereoscopic circulation visualization system that enables them to acquire 3D velocity subject data in He II. The scientists will create a skinny line of molecular tracers utilizing laser ionization in liquid helium. These tracers might be excited with a laser pulse to supply glow. Utilizing two cameras positioned within the perpendicular route, they will seize photographs to assemble a 3D profile of the tracer line.
“The 3D picture will assist us to know how turbulence impacts the warmth switch in He II,” doctoral pupil Toshiaki Kanai stated. “We shall be making use of this in our examine of heat-induced thermal counterflow in He II.”
Within the second undertaking, the researchers plan to make use of small micron-sized frozen hydrogen particles to determine the vortex tubes in He II. They are going to illuminate the particles on the vortices to take photographs of the vortex strains with the digicam. The vortex strains appear to be electrical cables with many small lightbulbs hooked up.
“Seeing these little bulbs on vortices will enable us to find out the place the vortex strains are and how briskly they transfer round,” stated post-doctoral analysis Yuan Tang.
The researchers will stack photographs of this phenomenon collectively to generate the 3D profile of the vortices. This technique will enable them to trace the movement of vortices, which can yield worthwhile details about their velocity and orientation statistics.
Guo’s group, with prior NSF assist, developed highly effective circulation visualization strategies used of their previous quantum turbulence analysis. They efficiently utilized these strategies to visualise vortex tubes in quantum fluids and wish to go additional by implementing three-dimensional processes to the equation.
Kanai will work on the stereoscopic molecular tagging velocimetry experiment. Tang will develop the scanning particle monitoring velocimetry system. The group is collaborating with Professor William Vinen from the College of Birmingham in the UK. Vinen is a famend knowledgeable in quantum turbulence, and he’ll work with information evaluation and consequence interpretation in each analysis actions.
The analysis shall be performed within the Nationwide Excessive Magnetic Subject Laboratory at Florida State College. The group additionally plans to conduct instructional outreach actions and conduct workshops and conferences to interact junior researchers.