Designfax weekly eMagazine

Subscribe Today!

Archives

View Archives

Partners

Manufacturing Center
Product Spotlight

Modern Applications News
Metalworking Ideas For
Today's Job Shops

Tooling and Production
Strategies for large
metalworking plants

Intro to reed switches, magnets, magnetic fields

This brief introductory video on the DigiKey site offers tips for engineers designing with reed switches. Dr. Stephen Day, Ph.D. from Coto Technology gives a solid overview on reed switches -- complete with real-world application examples -- and a detailed explanation of how they react to magnetic fields.
View the video.

Bi-color LEDs to light up your designs

Created with engineers and OEMs in mind, SpectraBright Series SMD RGB and Bi-Color LEDs from Visual Communi-cations Company (VCC) deliver efficiency, design flexibility, and control for devices in a range of industries, including mil-aero, automated guided vehicles, EV charging stations, industrial, telecom, IoT/smart home, and medical. These 50,000-hr bi-color and RGB options save money and space on the HMI, communicating two or three operating modes in a single component.
Learn more.

All about slip rings: How they work and their uses

Rotary Systems has put together a really nice basic primer on slip rings -- electrical collectors that carry a current from a stationary wire into a rotating device. Common uses are for power, proximity switches, strain gauges, video, and Ethernet signal transmission. This introduction also covers how to specify, assembly types, and interface requirements. Rotary Systems also manufactures rotary unions for fluid applications.
Read the overview.

Seifert thermoelectric coolers from AutomationDirect

Automation-Direct has added new high-quality and efficient stainless steel Seifert 340 BTU/H thermoelectric coolers with 120-V and 230-V power options. Thermoelectric coolers from Seifert use the Peltier Effect to create a temperature difference between the internal and ambient heat sinks, making internal air cooler while dissipating heat into the external environment. Fans assist the convective heat transfer from the heat sinks, which are optimized for maximum flow.
Learn more.

EMI shielding honeycomb air vent panel design

Learn from the engineering experts at Parker how honeycomb air vent panels are used to help cool electronics with airflow while maintaining electromagnetic interference (EMI) shielding. Topics include: design features, cell size and thickness, platings and coatings, and a stacked design called OMNI CELL construction. These vents can be incorporated into enclosures where EMI radiation and susceptibility is a concern or where heat dissipation is necessary. Lots of good info.
Read the Parker blog.

What is 3D-MID? Molded parts with integrated electronics from HARTING

3D-MID (three-dimensional mechatronic integrated devices) technology combines electronic and mechanical functionalities into a single, 3D component. It replaces the traditional printed circuit board and opens up many new opportunities. It takes injection-molded parts and uses laser-direct structuring to etch areas of conductor structures, which are filled with a copper plating process to create very precise electronic circuits. HARTING, the technology's developer, says it's "Like a PCB, but 3D." Tons of possibilities.
View the video.

Loss-free conversion of 3D/CAD data

CT CoreTech-nologie has further developed its state-of-the-art CAD converter 3D_Evolution and is now introducing native interfaces for reading Solidedge and writing Nx and Solidworks files. It supports a wide range of formats such as Catia, Nx, Creo, Solidworks, Solidedge, Inventor, Step, and Jt, facilitating smooth interoperability between different systems and collaboration for engineers and designers in development environments with different CAD systems.
Learn more.

Top 5 reasons for solder joint failure

Solder joint reliability is often a pain point in the design of an electronic system. According to Tyler Ferris at ANSYS, a wide variety of factors affect joint reliability, and any one of them can drastically reduce joint lifetime. Properly identifying and mitigating potential causes during the design and manufacturing process can prevent costly and difficult-to-solve problems later in a product lifecycle.
Read this informative ANSYS blog.

Advanced overtemp detection for EV battery packs

Littelfuse has introduced TTape, a ground-breaking over-temperature detection platform designed to transform the management of Li-ion battery systems. TTape helps vehicle systems monitor and manage premature cell aging effectively while reducing the risks associated with thermal runaway incidents. This solution is ideally suited for a wide range of applications, including automotive EV/HEVs, commercial vehicles, and energy storage systems.
Learn more.

Benchtop ionizer for hands-free static elimination

EXAIR's Varistat Benchtop Ionizer is the latest solution for neutralizing static on charged surfaces in industrial settings. Using ionizing technology, the Varistat provides a hands-free solution that requires no compressed air. Easily mounted on benchtops or machines, it is manually adjustable and perfect for processes needing comprehensive coverage such as part assembly, web cleaning, printing, and more.
Learn more.

LED light bars from AutomationDirect

Automation-Direct adds CCEA TRACK-ALPHA-PRO series LED light bars to expand their offering of industrial LED fixtures. Their rugged industrial-grade anodized aluminum construction makes TRACKALPHA-PRO ideal for use with medium to large-size industrial machine tools and for use in wet environments. These 120 VAC-rated, high-power LED lights provide intense, uniform lighting, with up to a 4,600-lumen output (100 lumens per watt). They come with a standard bracket mount that allows for angle adjustments. Optional TACLIP mounts (sold separately) provide for extra sturdy, vibration-resistant installations.
Learn more.

World's first metalens fisheye camera

2Pi Optics has begun commercial-ization of the first fisheye camera based on the company's proprietary metalens technology -- a breakthrough for electronics design engineers and product managers striving to miniaturize the tiny digital cameras used in advanced driver-assistance systems (ADAS), AR/VR, UAVs, robotics, and other industrial applications. This camera can operate at different wavelengths -- from visible, to near IR, to longer IR -- and is claimed to "outperform conventional refractive, wide-FOV optics in all areas: size, weight, performance, and cost."
Learn more.

Orbex offers two fiber optic rotary joint solutions

Orbex Group announces its 700 Series of fiber optic rotary joint (FORJ) assemblies, supporting either single or multi-mode operation ideal for high-speed digital transmission over long distances. Wavelengths available are 1,310 or 1,550 nm. Applications include marine cable reels, wind turbines, robotics, and high-def video transmission. Both options feature an outer diameter of 7 mm for installation in tight spaces. Construction includes a stainless steel housing.
Learn more.

Mini tunnel magneto-resistance effect sensors

Littelfuse has released its highly anticipated 54100 and 54140 mini Tunnel Magneto-Resistance (TMR) effect sensors, offering unmatched sensitivity and power efficiency. The key differentiator is their remarkable sensitivity and 100x improvement in power efficiency compared to Hall Effect sensors. They are well suited for applications in position and limit sensing, RPM measurement, brushless DC motor commutation, and more in various markets including appliances, home and building automation, and the industrial sectors.
Learn more.

Panasonic solar and EV components available from Newark

Newark has added Panasonic Industry's solar inverters and EV charging system components to their power portfolio. These best-in-class products help designers meet the growing global demand for sustainable and renewable energy mobility systems. Offerings include film capacitors, power inductors, anti-surge thick film chip resistors, graphite thermal interface materials, power relays, capacitors, and wireless modules.
Learn more.

U.S. scientists make matter and antimatter from light

A new study demonstrates a long-predicted process for generating matter directly from light -- plus evidence that magnetism can bend polarized photons along different paths in a vacuum.

Scientists studying particle collisions at the Relativistic Heavy Ion Collider (RHIC), a U.S. Department of Energy Office of Science user facility for nuclear physics research at DOE's Brookhaven National Laboratory, have produced definitive evidence for two physics phenomena predicted more than 80 years ago. The results were derived from a detailed analysis of more than 6,000 pairs of electrons and positrons produced in glancing particle collisions at RHIC and are published in Physical Review Letters.

The primary finding is that pairs of electrons and positrons -- particles of matter and antimatter -- can be created directly by colliding very energetic photons, which are quantum "packets" of light. This conversion of energetic light into matter is a direct consequence of Einstein's famous E=mc² equation, which states that energy and matter (or mass) are interchangeable. Nuclear reactions in the sun and at nuclear power plants regularly convert matter into energy. Now scientists have converted light energy directly into matter in a single step.

Making matter from light: Two gold (Au) ions (red) move in opposite directions at 99.995% of the speed of light (v, for velocity, = approximately c, the speed of light). As the ions pass one another without colliding, two photons (γ) from the electromagnetic cloud surrounding the ions can interact with each other to create a matter-antimatter pair: an electron (e^-) and positron (e⁺).

 

 

 

 

The second result shows that the path of light traveling through a magnetic field in a vacuum bends differently depending on how that light is polarized. Such polarization-dependent deflection (known as birefringence) occurs when light travels through certain materials. (This effect is similar to the way wavelength-dependent deflection splits white light into rainbows.) This new work is the first demonstration of polarization-dependent light-bending in a vacuum.

Both results depend on the ability of RHIC's STAR detector -- the Solenoid Tracker at RHIC -- to measure the angular distribution of particles produced in glancing collisions of gold ions moving at nearly the speed of light.

Colliding clouds of photons
Such capabilities didn't exist when physicists Gregory Breit and John A. Wheeler first described the hypothetical possibility of colliding light particles to create pairs of electrons and their antimatter counterparts, known as positrons, in 1934.

"In their paper, Breit and Wheeler already realized this is almost impossible to do," said Brookhaven Lab physicist Zhangbu Xu, a member of RHIC's STAR Collaboration. "Lasers didn't even exist yet! But Breit and Wheeler proposed an alternative: accelerating heavy ions. And their alternative is exactly what we are doing at RHIC."

The STAR detector at the Relativistic Heavy Ion Collider measured the angular distribution of particles produced in glancing collisions of gold ions moving at nearly the speed of light to provide evidence for two physics phenomena predicted more than 80 years ago.

 

 

 

 

An ion is essentially a naked atom, stripped of its electrons. A gold ion, with 79 protons, carries a powerful positive charge. Accelerating such a charged heavy ion to very high speeds generates a powerful magnetic field that spirals around the speeding particle as it travels -- like current flowing through a wire.

"If the speed is high enough, the strength of the circular magnetic field can be equal to the strength of the perpendicular electric field," Xu said. And that arrangement of perpendicular electric and magnetic fields of equal strength is exactly what a photon is -- a quantized "particle" of light. "So, when the ions are moving close to the speed of light, there are a bunch of photons surrounding the gold nucleus, traveling with it like a cloud."

At RHIC, scientists accelerate gold ions to 99.995% of the speed of light in two accelerator rings.

"We have two clouds of photons moving in opposite directions with enough energy and intensity that when the two ions graze past each other without colliding, those photon fields can interact," Xu said.

STAR physicists tracked the interactions and looked for the predicted electron-positron pairs.

But such particle pairs can be created by a range of processes at RHIC, including through "virtual" photons, a state of photon that exists briefly and carries an effective mass. To be sure the matter-antimatter pairs were coming from real photons, scientists have to demonstrate that the contribution of "virtual" photons does not change the outcome of the experiment.

To do that, the STAR scientists analyzed the angular distribution patterns of each electron relative to its partner positron. These patterns differ for pairs produced by real photon interactions versus virtual photons.

"We also measured all the energy, mass distributions, and quantum numbers of the systems. They are consistent with theory calculations for what would happen with real photons," said Daniel Brandenburg, a Goldhaber Fellow at Brookhaven Lab, who analyzed the STAR data on this discovery.

Other scientists have tried to create electron-positron pairs from collisions of light using powerful lasers -- focused beams of intense light. But the individual photons within those intense beams don't have enough energy yet, Brandenburg said.

One experiment at the SLAC National Accelerator Laboratory in 1997 succeeded by using a nonlinear process. Scientists there first had to boost the energy of the photons in one laser beam by colliding it with a powerful electron beam. Collisions of the boosted photons with multiple photons simultaneously in an enormous electromagnetic field created by another laser produced matter and antimatter.

"Our results provide clear evidence of direct, one-step creation of matter-antimatter pairs from collisions of light as originally predicted by Breit and Wheeler," Brandenburg said. "Thanks to RHIC's high-energy heavy ion beam and the STAR detector's large acceptance and precision measurements, we are able to analyze all the kinematic distributions with high statistics to determine that the experimental results are indeed consistent with real photon collisions."

Bending light in a vacuum
STAR's ability to measure the tiny deflections of electrons and positrons produced almost back-to-back in these events also gave the physicists a way to study how light particles interact with the powerful magnetic fields generated by the accelerated ions.

"The cloud of photons surrounding the gold ions in one of RHIC's beams is shooting into the strong circular magnetic field produced by the accelerated ions in the other gold beam," said Chi Yang, a long-time STAR collaborator from Shandong University who spent his entire career studying electron-positron pairs produced from various processes at RHIC. "Looking at the distribution of particles that come out tells us how polarized light interacts with the magnetic field."

Bending polarized light: This illustration shows how light with different polarization directions (indicated by black arrows) passes through a material along two different paths (yellow beams). This is called the birefringence effect. Results from RHIC provide evidence that birefringence also happens in a magnetic field in a vacuum.

 

 

 

 

Werner Heisenberg and Hans Heinrich Euler in 1936, and John Toll in the 1950s, predicted that a vacuum of empty space could be polarized by a powerful magnetic field and that such a polarized vacuum should deflect the paths of photons depending on photon polarization. Toll, in his thesis, also detailed how light absorption by a magnetic field depends on polarization and its connection to the refractive index of light in a vacuum. This polarization-dependent deflection, or birefringence, has been observed in many types of crystals. There was also a recent report of the light coming from a neutron star bending this way, presumably because of its interactions with the star's magnetic field. But no Earth-based experiment has detected birefringence in a vacuum.

At RHIC, the scientists measured how the polarization of the light affected whether the light was "absorbed" by the magnetic field.

This is similar to the way polarized sunglasses block certain rays from passing through if they don't match the polarization of the lenses, Yang explained. In the case of the sunglasses, in addition to seeing less light get through, you could, in principle, measure an increase in the temperature of the lens material as it absorbs the energy of the blocked light. At RHIC, the absorbed light energy is what creates the electron-positron pairs.

"When we look at the products produced by photon-photon interactions at RHIC, we see that the angular distribution of the products depends on the angle of the polarization of the light. This indicates that the absorption (or passing) of light depends on its polarization," Yang said.

This is the first Earth-based experimental observation that polarization affects the interactions of light with the magnetic field in the vacuum -- the vacuum birefringence predicted in 1936.

"Both of these findings build on predictions made by some of the great physicists in the early 20th century," said Frank Geurts, a professor at Rice University, whose team built and operated the state-of-the-art "Time-of-Flight" detector components of STAR that were necessary for this measurement. "They are based on fundamental measurements made possible only recently with the technologies and analysis techniques we have developed at RHIC."

Source: Brookhaven National Laboratory

Published September 2021

Rate this article