They say it’s about the size of an avocado, and weighs less than one pound.
According to Sandia National Laboratories, this first-of-its-kind device contains a passively pumped vacuum chamber for containing clouds of atomic particles that drive quantum sensors.
It also features titanium metal walls and sapphire windows.
And what exactly does it do?
Officials at the Albuquerque-based US nuclear research lab say it could potentially free the US military (and civilians around the world) from reliance on GPS satellites for navigational way-finding — a major next-gen scientific advance.
Sandia scientist Peter Schwindt told Breaking Defense that the device is small enough to enable highly accurate quantum positioning, timing and navigation (PNT) systems that in the future could be carried on vehicles, aircraft, satellites or even soldiers’ backpacks.
Potentially it could provide an alternate, or even a replacement for Global Positioning System satellites, which use highly accurate atomic clocks for PNT measurements.
Quantum sensors, based on lasers, already are being tested in laboratories around the world, but Schwindt cautioned that there is still development work — not just on vacuum chambers — to be done to be able to use them as replacements for GPS.
“Quantum sensors are a growing field, and there are lots of applications you can demonstrate in the lab,” explained Sandia postdoctoral scientist Bethany Little, who is contributing to the research.
“But when you move it into the real world there are lots of problems you have to solve. Two are making the sensor compact and rugged.
“The physics takes place all in a cubic centimeter (0.06 cubic inches) of volume, so anything larger than that is wasted space.”
Military leaders, especially within the Army, are ever-more worried about losing access to GPS signals on far flung battlefields, whether from enemy jamming, friendly interference from the plethora of electromagnetic spectrum using devices now equipping modern weaponry, or simply environmental conditions that block signals from reaching receivers.
A GPS sensor determines its location by using the amount of time it takes to receive a signal from a satellite.
To defeat so-called spoofing GPS signals, a wireless sensor measures the angle at which it receives an RF wave.
The more precisely the sensor can measure this time delay or angle of arrival, the more it can accurately determine location or enhance security.
Quantum sensors for PNT use atomic accelerometers or gyroscopes that “measure acceleration and rotation by shining lasers into small clouds of rubidium gas” contained in vacuum chambers.
Such sensors already exist but “they’re too bulky and power-hungry to use in an airplane’s navigation system … because they need a large vacuum system to work, one that needs thousands of volts of electricity,” the release says.
A vacuum chamber is a key component, trapping the rubidium atoms and keeping out other types of gasses that would mess up the finely tuned measurements made by the lasers.
But rather than using electrical power for the pump that maintains the vacuum, Sandia’s novel solution was to use chemical reactions to bind “foreign” gasses.
The device itself further has “walls” made from titanium and sapphire — a process that required complex construction methods similar to those used by Sandia to build nuclear weapons components — that also serve as barriers to contaminants.
While atomic accelerometers and gyroscopes already exist, they’re too bulky and power-hungry to use in an airplane’s navigation system. That’s because they need a large vacuum system to work, one that needs thousands of volts of electricity.
The quantum navigator utilizes entirely different technology.
Using a starting point as a fixed reference and calibrated to the patterns of Earth’s magnetic field, data from a quantum navigation system will give us all the information we need to accurately determine where we are.
Benefits of quantum navigation and positioning systems over GPS are improved accuracy, no reliance on satellite, indoor usage, less vulnerability to hacking and spoofing and no sensitivity to electromagnetic pulse attacks (which would happen for example after an atomic attack, most likely causing GPS systems to stop working).
With spoofing, the receiver gets false data, resulting into a false location and/or a false time. There have been recent events where GPS signals told ships they were on land, while they were actually at sea.
The Sandia team has shown that quantum sensing can work without a high-powered vacuum system.
This shrinks the package to a practical size without sacrificing reliability.
Instead of a powered vacuum pump, which whisks away molecules that leak in and wreck measurements, a pair of devices called getters use chemical reactions to bind intruders.
The getters are each about the size of a pencil eraser so they can be tucked inside two narrow tubes sticking out of the titanium package. They also work without a power source.
To further keep out contaminants, Schwindt partnered with Sandia materials scientists to build the chamber out of titanium and sapphire.
These materials are especially good at blocking out gasses like helium, which can squeeze through stainless steel and Pyrex glass.
Sandia’s “avocado” has been running for a full year, proving that high-powered vacuum systems are not necessary for reliable quantum sensing.
The goal is to keep it “sealed and operational for five years, an important milestone toward showing the technology is ready to be fielded.”
Despite the comparison to an avocado, Schwindt said lab scientists haven’t given the vacuum chamber a cute nickname, yet.
Sources: Breaking Defense, Phys.org, Wired, Futurism.com, TUDelft, GPSWorld.com