NASA CAL: Cold atom laboratory chills atoms to new lows

Artist's concept of an atom chip for use by NASA's Cold Atom Laboratory (CAL) aboard the International Space Station. 

CAL will use lasers to cool atoms to ultracold temperatures. 

Credit: NASA

NASA's Cold Atom Laboratory (CAL) mission has succeeded in producing a state of matter known as a Bose-Einstein condensate, a key breakthrough for the instrument leading up to its debut on the International Space Station in late 2016.

A Bose-Einstein condensate (BEC) is a collection of atoms in a dilute gas that have been lowered to extremely cold temperatures and all occupy the same quantum state, in which all of the atoms have the same energy levels.

At a critical temperature, atoms begin to coalesce, overlap and become synchronized like dancers in a chorus line.

The resulting condensate is a new state of matter that behaves like a giant, by atomic standards, wave.

"It's official. CAL's ground testbed is the coolest spot at NASA's Jet Propulsion Laboratory at 200 nano-Kelvin [200 billionths of 1 Kelvin], "said Cold Atom Laboratory Project Scientist Rob Thompson at JPL in Pasadena, California.

"Achieving Bose-Einstein condensation in our prototype hardware is a crucial step for the mission."

Although these quantum gases had been created before elsewhere on Earth, the Cold Atom Laboratory will explore the condensates in an entirely new regime: The microgravity environment of the space station. It will enable groundbreaking research in temperatures colder than any found on Earth.

CAL will be a facility for studying ultra-cold quantum gases on the space station. In the station's microgravity environment, interaction times and temperatures as low as one picokelvin (one trillionth of one Kelvin, or 293 trillion times below room temperature) should be achievable.

That's colder than anything known in nature, and the experiments with CAL could potentially create the coldest matter ever observed in the universe.

These breakthrough temperatures unlock the potential to observe new quantum phenomena and test some of the most fundamental laws of physics.

This sequence of false-colour images shows the formation of a Bose-Einstein condensate in the Cold Atom Laboratory prototype at NASA's Jet Propulsion Laboratory as the temperature gets progressively closer to absolute zero, the temperature at which atoms have almost no motion. 

Red in each figure indicates higher density. 

Credit: NASA/JPL-Caltech

First observed in 1995, Bose-Einstein condensation has been one of the "hottest" topics in physics ever since.

The condensates are different from normal gases; they represent a distinct state of matter that starts to form typically below a millionth of a degree above absolute zero, the temperature at which atoms have the least energy and are close to motionless.

Familiar concepts of "solid," "liquid" and "gas" no longer apply at such cold temperatures; instead, atoms do bizarre things governed by quantum mechanics, such as behaving as waves and particles at the same time.

Cold Atom Laboratory researchers used lasers to optically cool rubidium atoms to temperatures almost a million times colder than that of the depths of space.

The atoms were then magnetically trapped, and radio waves were used to cool the atoms 100 times lower.

The radiofrequency radiation acts like a knife, slicing away the hottest atoms from the trap so that only the coldest remain.

The research is at the point where this process can reliably create a Bose-Einstein condensate in just seconds.

Members of the Cold Atom Laboratory team at NASA's Jet Propulsion Laboratory are seen here with their ground-based testbed, which can reliably create a Bose-Einstein condensate. 

Pictured from left to right, Anita Sengupta, Ethan Elliott, Rob Thompson and Markus Krutzik. 

Credit: NASA/JPL-Caltech

"This was a tremendous accomplishment for the CAL team. It confirms the fidelity of the instrument system design and provides us a facility to perform science and hardware verifications before we get to the space station," said CAL Project Manager Anita Sengupta of JPL.

While so far, the Cold Atom Laboratory researchers have created Bose-Einstein condensates with rubidium atoms, eventually they will also add in potassium.

The behaviour of two condensates mixing together will be fascinating for physicists to observe, especially in space.

Besides merely creating Bose-Einstein condensates, CAL provides a suite of tools to manipulate and probe these quantum gases in a variety of ways.

It has a unique role as a facility for the atomic, molecular and optical physics community to study cold atomic physics in microgravity, said David Aveline of JPL, CAL ground testbed lead.

"Instead of a state-of-the-art telescope looking outward into the cosmos, CAL will look inward, exploring physics at the atomic scale," Aveline said.

Magnifying the Universe - Video

Copyright 2012. Magnifying the Universe by Number Sleuth.

Rice lab mimics Jupiter's Trojan asteroids inside a single atom - YouTube

Rice University physicists have built an accurate model of part of the solar system inside a single atom.

In a new paper in Physical Review Letters, Rice's team and collaborators from Oak Ridge National Laboratory and the Vienna University of Technology showed they could make an electron orbit the atomic nucleus in the same way that Jupiter's Trojan asteroids orbit the sun.

The findings uphold a 1920 prediction by physicist Niels Bohr.

"Bohr predicted that quantum mechanical descriptions of the physical world would, for systems of sufficient size, match the classical descriptions provided by Newtonian mechanics," said lead researcher Barry Dunning, Rice's Sam and Helen Worden Professor of Physics and chair of the Department of Physics and Astronomy.

"Bohr also described the conditions under which this correspondence could be observed. In particular, he said it should be seen in atoms with very high principal quantum numbers, which are exactly what we study in our laboratory."

Bohr was a pioneer of quantum physics. His 1913 atomic model, which is still widely invoked today, postulated a small nucleus surrounded by electrons moving in well-defined orbits and shells.

The word "quantum" in quantum mechanics derives from the fact that these orbits can have only certain well-defined energies.

Jumps between these orbits lead to absorption or emission of specific amounts of energy termed quanta.

As an electron gains energy, its quantum number increases, and it jumps to higher orbits that circle ever farther from the nucleus.

In the new experiments, Rice graduate students Brendan Wyker and Shuzhen Ye began by using an ultraviolet laser to create a Rydberg atom.

Rydberg atoms contain a highly excited electron with a very large quantum number. In the Rice experiments, potassium atoms with quantum numbers between 300 and 600 were studied.

LHC Physicists Get an Antimatter Surprise

This giant magnetic is part of the LHCb experiment at the Large Hadron Collider in Geneva, Switzerland.

CREDIT: CERN/LHCb

The world's largest atom smasher, designed as a portal to a new view of physics, has produced its first peek at the unexpected: bits of matter that don't mirror the behavior of their antimatter counterparts.

The discovery, if confirmed, could rewrite the known laws of particle physics and help explain why our universe is made mostly of matter and not antimatter.

Scientists at the Large Hadron Collider, the 17-mile (27 km) circular particle accelerator underground near Geneva, Switzerland, have been colliding protons at high speeds to create explosions of energy. From this energy many subatomic particles are produced.

Now researchers at the accelerator's LHCb experiment are reporting that some matter particles produced inside the machine appear to be behaving differently from their antimatter counterparts, which might provide a partial explanation to the mystery of antimatter.

CAesium Fountain atomic clock with the world's best long-term accuracy

A caesium fountain clock that keeps the United Kingdom's atomic time is now the most accurate long-term timekeeper in the world. 

This has been ascertained by a new evaluation of the clock that will be published in the October 2011 issue of the international scientific journal Metrologia by a team of physicists at the National Physical Laboratory (NPL) in the United Kingdom and Penn State University in the United States. 

This image shows the clock, NPL-CsF2, which is located at the National Physical Laboratory in Teddington, U.K. The whole device is approximately 8.2 feet (2.5 m) high.

Atoms are tossed up 3.2 feet (1 m), approximately 12 inches (30 cm) above the cavity that is contained inside a vacuum vessel. 

The large external cylinder screens the atoms inside the clock from the relatively large and unstable external magnetic field. Credit: National Physical Laboratory, United Kingdom.

The atomic clock housed in Britain's National Physical Laboratory (NPL) is the world's most accurate, according to new research.

The clock is a caesium fountain clock, meaning that the "tick" is provided by the measurement of the energy required to change the caesium atoms' spin.

Caesium atoms are placed into a cavity, and exposed to electromagnetic radiation of different wavelengths. Once the spin "flips", the waves are at the right frequency to define what a second is.

In the case of caesium, that quantity is defined as 9.2GHz (or, to be appropriately exact, 9,192,631,770Hz). When the spin flips, the clock operators can set the frequency at that point, and work backward to determine the exact length of a second.

The international Bureau of Weights and Measures takes readings from a selection of "primary frequency standards", in France, the US, Germany, Japan -- and, the most accurate of them all, in the UK.

A team led by NPL's Krzysztof Szymaniec and colleagues at Pennsylvania State University found that Britain's atomic clock was accurate to one part in 4,300,000,000,000,000, nearly doubling the accuracy found when the clocks were last measured in 2010. That level of precision means that NPL's clock wouldn't stray by more than a second in 138 million years.

While that might seem like overegging the pudding in terms of making sure your alarm clock goes off in time for you to get to work, the definition of most electrical units are based on these measurements, and given the vast amounts of energy and data pouring through the world's computer systems, even a tiny change can have measurable economic impact.

"The frequency we measure is not necessarily the one prescribed by the definition of a second, which requires that all the external fields and 'perturbations' would be removed," Szymaniec stated. "In many cases we can't remove these perturbations; but we can measure them precisely, we can assess them, and introduce corrections for them."

"It's vital for the UK as an economy to maintain a set of standards, a set of procedures, that underpin technical development," he added.

Non-Bees Stinging Tumours

They're called "nanobees," and they're not insects -- they're tiny particles designed to destroy cancer cells by delivering a synthesized version of toxin called melittin that is found in bees.

"Melittin, which would otherwise result in substantial destruction of your red blood cells and other normal tissues if it were delivered intravenously alone, is completely safe when it's on a nanoparticle," said Dr. Samuel Wickline, director of the Siteman Center of Cancer Nanotechnology Excellence at Washington University in St. Louis, Missouri.

Nanobees are one of the latest examples of how nanotechnology may change the way diseases are treated.

Nanotechnology encompasses a wide array of innovations that make use of structures that are 100 nanometers or smaller. That means they generally cannot be seen under a regular microscope, but are larger than individual atoms. For example, a nanobee is less than 10 times diameter of a red blood cell, Wickline said.

Particles on the nanoscale are small enough to enter cells, but big enough to carry large doses of drugs, said Robert Langer, Institute professor at the Massachusetts Institute of Technology and a leader in the nanotech field. Watch MIT researchers talk about nanotechnology

"We are gradually forming a pipeline of nanotechnology-based products," said Piotr Grodzinski, director of the National Cancer Institute's Alliance for Nanotechnology in Cancer, a program that funds eight Centers of Cancer Nanotechnology Excellence in the U.S., including Wickline's and Langer's research initiatives. "These things are happening as we speak."

There have already been two approved cancer treatments on the market that make use of nanoparticles: ovarian cancer drug Doxil, approved in 1995, and breast cancer drug Abraxane, approved in 2005. Both of these involve medication bound with nanoparticles that circulate in the bloodstream for longer than conventional drugs and are expected to migrate to the tumor site, Grodzinski said. These drugs are being tested in some of the eight clinical trials associated with the NCI nano program.