Monday, March 11, 2024

Giving particle detectors a boost

Argonne researchers have created a new device that acts like a superconductivity switch, helping boost the signal of tiny particles in particle colliders

DOE/ARGONNE NATIONAL LABORATORY

16x9_Big Islands Colorized Final — IMAGE:
FALSE COLOR SCANNING ELECTRON MICROSCOPE IMAGE OF A PARALLEL-CHANNEL SUPERCONDUCTING NANOCRYOTRON. BLUE HIGHLIGHTS THE GROUND PLANE, GREY SHOWS THE TRENCH AND NANOWIRE GAPS, GREEN REPRESENTS THE EFFECTIVE NBN CHANNEL, AND RED SIGNIFIES THE NBN GATE TO CHOKE CONSTRICTION. SCALE BARS CORRESPOND TO 2 ΜM.
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CREDIT: (IMAGE BY ARGONNE NATIONAL LABORATORY.)

Device could help facilitate the operation of new particle colliders, such as the Electron-Ion Collider.

In particle colliders that reveal the hidden secrets of the tiniest constituents of our universe, minute particles leave behind extremely faint electrical traces when they are generated in enormous collisions. Some detectors in these facilities use superconductivity — a phenomenon in which electricity is carried with zero resistance at low temperatures — to function.

For scientists to more accurately observe the behavior of these particles, these weak electrical signals, or currents, need to be multiplied by an instrument capable of turning a faint electrical flicker into a real jolt.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have developed a new device that acts as a “current multiplier.” This device, called a nanocryotron, is a prototype for a mechanism that could turn up a particle’s electrical signal high enough to a level where it temporarily turns off the superconductivity of the material, essentially creating a kind of on-off switch.

“This work is especially important for collider experiments, such as those that will be performed at the Electron-Ion Collider at Brookhaven National Laboratory.” — Argonne Distinguished Fellow and group leader Zein-Eddine Meziani

“We’re taking a small signal and using it to trigger an electric cascade,” said Tomas Polakovic, one of Argonne’s Maria Goeppert Mayer Fellows and an author of the study. “We’re going to funnel the very small current of these detectors into the switching device, which can be then used to switch a much bigger current.”

To prepare the nanocryotron for a collider experiment will take some more work because of the high magnetic fields involved. While today’s particle detectors can withstand magnetic fields of several tesla in strength, this switch’s performance degrades in high magnetic fields.

“Finding ways to make the device work in higher magnetic fields is key to incorporating it into a real experiment,” said Argonne graduate research assistant Timothy Draher, another author of the study.

To make this possible, the researchers plan to change the geometry of the material and introduce defects, or tiny holes. These defects will help researchers stabilize small superconducting vortices in the material, the movement of which can lead to an unanticipated disruption of superconductivity.

The nanocryotron was created by using electron beam lithography, a kind of stenciling technique that uses a beam of electrons to remove a polymer film to expose a particular region of interest. That region of interest is then etched using plasma ion etching.

“We basically just strip away the parts that are exposed, leaving behind the device that we want to use,” Draher said.

According to Argonne physicist Valentine Novosad, another author of the study, the new device also could serve as the basis for a kind of electronic logic circuitry.

“This work is especially important for collider experiments, such as those that will be performed at the Electron-Ion Collider at Brookhaven National Laboratory. There, superconducting nanowire detectors, positioned close to the beams, would require microelectronics immune to magnetic fields,” said Argonne Distinguished Fellow and group leader Zein-Eddine Meziani.

A paper based on the study, “Design and performance of parallel-channel nanocryotrons in magnetic fields,” appeared in the Dec. 18, 2023 edition of Applied Physics Letters. In addition to Draher, Zein-Eddine, Polakovic and Novosad, authors include Yi Li, John Pearson, Alan Dibos and Zhili Xiao.

The work was funded by DOE’s Office of Science, Office of Nuclear Physics. Work to perform reactive ion etching of the superconducting films in the experiment was carried out at the Center for Nanoscale Materials, a DOE User Facility.

About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

JOURNAL

Applied Physics Letters

DOI

10.1063/5.0180709

ARTICLE TITLE

Design and performance of parallel-channel nanocryotrons in magnetic fields

Robotic interface masters a soft touch

EPFL researchers have developed a haptic device capable of reproducing the softness of various materials, from a marshmallow to a beating heart, overcoming a deceptively complex challenge that has previously eluded roboticists

ECOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE

SORI (Softness Rendering Interface) — IMAGE:
SORI (SOFTNESS RENDERING INTERFACE)
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CREDIT: JAMANI CAILLET

The perception of softness can be taken for granted, but it plays a crucial role in many actions and interactions – from judging the ripeness of an avocado to conducting a medical exam, or holding the hand of a loved one. But understanding and reproducing softness perception is challenging, because it involves so many sensory and cognitive processes.

Robotics researchers have tried to address this challenge with haptic devices, but previous attempts have not distinguished between two primary elements of softness perception: cutaneous cues (sensory feedback from the skin of the fingertip), and kinesthetic cues (feedback about the amount of force on the finger joint).

“If you press on a marshmallow with your fingertip, it’s easy to tell that it’s soft. But if you place a hard biscuit on top of that marshmallow and press again, you can still tell that the soft marshmallow is underneath, even though your fingertip is touching a hard surface,” explains Mustafa Mete, a PhD student in the Reconfigurable Robotics Lab in the School of Engineering. “We wanted to see if we could create a robotic platform that can do the same.”

With SORI (Softness Rendering Interface), the RRL, led by Jamie Paik, has achieved just that. By decoupling cutaneous and kinesthetic cues, SORI faithfully recreate the softness of a range of real materials, filling a gap in the robotics field enabling many applications where softness sensation is critical – from deep-sea exploration to robot-assisted surgery.

The research appears in the Proceedings of the National Academy of Science (PNAS).

The Softness Rendering Interface (SORI) can recreate the softness of a range of materials

CREDIT

We all feel softness differently

Mete explains that neuroscientific and psychological studies show that cutaneous cues are largely based on how much skin is in contact with a surface, which is often related in part to the deformation of the object. In other words, a surface that envelopes a greater area of your fingertip will be perceived as softer. But because human fingertips vary widely in size and firmness, one finger may make greater contact with a given surface than another.

“We realized that the softness I feel may not be the same as the softness you feel, because of our different finger shapes. So, for our study, we first had to develop parameters for the geometries of a fingertip and its contact surface in order to estimate the softness cues for that fingertip,” Mete explains. Then, the researchers extracted the softness parameters from a range of different materials, and mapped both sets of parameters onto the SORI device.

Building on the RRL’s trademark origami robot research, which has fueled spinoffs for reconfigurable environments and a haptic joystick, SORI is equipped with motor-driven origami joints that can be modulated to become stiffer or more supple. Perched atop the joints is a dimpled silicone membrane. A flow of air inflates the membrane to varying degrees, to envelop a fingertip placed at its center.

With this novel decoupling of kinesthetic and cutaneous functionality, SORI succeeded in recreating the softness of a range of materials – including beef, salmon, and marshmallow – over the course of several experiments with two human volunteers. It also mimicked materials with both soft and firm attributes (such as a biscuit on top of a marshmallow, or a leather-bound book). In one virtual experiment, SORI even reproduced the sensation of a beating heart, to demonstrate its efficacy at rendering soft materials in motion.

Medicine is therefore a primary area of potential application for this technology; for example, to train medical students to detect cancerous tumors, or to provide crucial sensory feedback to surgeons using robots to perform operations.

Other applications include robot-assisted exploration of space or the deep ocean, where the device could enable scientists to feel the softness of a discovered object from a remote location. SORI is also a potential answer to one of the biggest challenges in robot-assisted agriculture: harvesting tender fruits and vegetables without crushing them.

“This is not intended to act as a softness sensor for robots, but to transfer the feeling of ‘touch’ digitally, just like sending photos or music,” Mete summarizes.