Cold Facts Digital – Page 63 – The go-to place for Cryogenics and Superconductivity

Elusive superconducting-transition signature seen for the first time

Researchers in the US report that they have observed the so-called “fourth signature” of superconducting phase transitions in materials known as cuprates. The result, obtained via photoemission spectroscopy of a cuprate called Bi2212, could shed fresh light on how these materials, which conduct electricity without resistance at temperatures of 77...

Multiphoton Generator on a Chip

Producing entangled photons whose properties are interdependent is key to several quantum communication technologies. Most techniques for generating these photons make them exclusively in pairs, and those that can produce more than two photons are difficult to implement. But researchers have now made a chip-sized device that can generate bunches...

AIP Awarded $12.5 Million Grant to Roll Back Underrepresentation of Undergraduate African Americans in Physics, Astronomy

TEAM-UP Together, a new initiative by the American Institute of Physics (AIP) and key physics and astronomy societies, boldly takes the first steps toward achieving a goal of doubling the number of African Americans graduating from college with undergraduate degrees in physics and astronomy by 2030. The AIP Foundation has...

In a Sea of Magic Angles, ‘Twistons’ Keep Electrons Flowing Through Three Layers of Graphene

The discovery of superconductivity in two ever-so-slightly twisted layers of graphene made waves a few years ago in the quantum materials community. With just two atom-thin sheets of carbon, researchers had discovered a simple device to study the resistance-free flow of electricity, among other phenomena related to the movement of...

Magnesium Diboride: A New Superconductor?

In an article recently published in the Journal of Applied Physics, researchers investigated the influence of strain and pressure on the superconductivity and electron-phonon coupling in magnesium diboride (MgB2). They also discussed the corresponding theoretical approaches and the future of nanostructure design. Background The discovery of MgB2 as a high-temperature superconductor with a...

Engineering the Quantum States in Solid Materials Using Light

A POSTECH research team led by Professors Gil-Ho Lee and Gil Young Cho (Department of Physics) has developed a platform that can control the properties of solid materials with light and measure them. Recognized for developing a platform to control and measure the properties of materials in various ways with light,...

Latest in Defining Cryogenics

Cold Compressors

A common way to provide cooling below the normal boiling point of helium (4.2K) is to reduce the pressure above the bath of liquid helium, thus also reducing the bath’s equilibrium saturation temperature. For example, to produce a 1.8K bath of liquid helium, the saturation pressure has to be reduced...

Kapitza Conductance

Kapitza conductance refers to the heat transfer between a solid surface and a fluid that covers that surface. Fundamentally, it describes the inherent difficulty in transferring energy from a solid to the fluid covering the solid surface. This phenomenon was first observed by P. L. Kapitza in 1941 while studying...

Thermosyphons

A thermosyphon (or thermosiphon) is a device that transfers heat via natural convection in a fluid. The natural convection is driven by gravity with the colder, denser fluid flowing downhill and the warmer, less dense fluid flowing back up. Thus, thermosyphons connect an object to be cooled with a reservoir...

Latest in Cryo Central

Cryogenic Electronics

Randall Kirschman, consulting physicist, Mountain View, California ExtElect@gmail.com Cryogenic electronics—the operation of electronic devices, circuits, and systems at cryogenic temperatures—has been a valuable technology for decades. Cryogenic electronics (also referred to as low-temperature electronics, or cold electronics) can be based on semiconductive devices, on superconductive devices, or on a combination...

Particle Physics: High Energy Physics

Cryogenics and High-Energy Physics 1. From symmetry magazine: http://www.symmetrymagazine.org/cms/?pid=1000627: Cryogenics is the study of how materials behave at temperatures near absolute zero. In high-energy particle accelerators, such frigid temperatures reduce the electrical resistance of wires in superconducting magnets, increasing the magnet strength and allowing faster particle acceleration. The same holds...

HTS Degaussing Systems

From the Spring 2009 issue of Cold Facts (Volume 25, Number 2): Thanks to a joint project by the US Navy and a number of industry partners, high temperature superconducting (HTS) technology is now at the heart of an advanced degaussing system aboard the USS Higgins at the naval station...

Magnetic Resonance Imaging

From http://www.superconductors.org: An area where superconductors can perform a life-saving function is in the field of biomagnetism. Doctors need a non-invasive means of determining what’s going on inside the human body. By impinging a strong superconductor-derived magnetic field into the body, hydrogen atoms that exist in the body’s water and...

Latest in Ask the Experts

An Issue of Pressure and Flow Rate in a Supply Tank

Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...

Using MLI on VJ Line Joints or Cryo Storage Tanks

When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...

Separated layers of ice over a pipe

I want to know that why there are different layers of ice over a pipe carrying a cryogenic fluid, each layer separated with clear marks / lines? What do these layers signify?

Using nitrogen as a cryogen

Is it possible to achieve -200˚C using nitrogen as a cryogen?

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