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

Problem sending LN2 through hoses – need to minimize heat leak

We use liquid nitrogen at our power station to freeze light and heavy water in piping. The ice plug formed within the piping acts as a “valve” and allows us to work on a section of the piping system that otherwise cannot be isolated. The liquid nitrogen enters a jacket...

Cyclotron founder Henry Blosser leaves large legacy at MSU

When Michigan State University went looking for someone who could build a cyclotron from scratch, Henry Blosser wasn’t the first choice. He got the job only after two of his co-workers at Oak Ridge National Laboratory and a Canadian researcher had turned it down.

GE completes trials of HTS technology for power generation

GE’s Power Conversion has successfully completed trials of Hydrogenie, a power generator incorporating groundbreaking technologies that enable highly efficient production of electricity in a small space. Hydrogenie makes use of superconductors instead of copper for the rotor windings on the motor, operating at 43 Kelvin or -230°C.

Electron conflict leads to ‘bad traffic’ on way to superconductivity

Rice University physicists on the hunt for the origins of high-temperature superconductivity have published new findings about a seemingly contradictory state in which a material simultaneously exhibits the conflicting characteristics of both a metallic conductor and an insulator.

Light tsunami in a superconductor

An international research team at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has managed to selectively influence superconductivity with a powerful terahertz laser. This very precise laser light turns into a vortex which moves through the superconductor like a tsunami.

AMS experiment measures antimatter excess in space

The international team running the Alpha Magnetic Spectrometer (AMS) announced on April 3 the first results in its search for dark matter. The AMS paper, to be published in the journal Physical Review Letters, reports the observation of an excess of positrons in the cosmic ray flux. AMS spokesperson Professor...

Latest in Defining Cryogenics

Mixed Refrigerant Cycles

Most cryogenic refrigeration systems, both large scale systems and cryocoolers, use helium as a working fluid. There are a number of advantages to helium, not the least of which is that helium remains a fluid down to the lowest achievable temperatures. In order to freeze helium, pressures of over 20...

Fountain Pumps and He II Phase Separators

Helium II (He II), the second liquid phase of the 4He isotope described in this column in Cold Facts Spring 2010 (http://2csa.us/he2), can be modeled as consisting of two interpenetrating fluids. One, the superfluid component, has zero viscosity and entropy and the other, the normal fluid component, has nonzero viscosity...

Turboexpanders

A vital technology in the refrigerators and liquefiers described in Cold Facts Volume 31 Number 3 is that of turboexpanders. These devices are rotating machines in which the process fluid (e.g., helium) does work against the turboexpander while moving from high pressure to a lower pressure and thus is cooled....

Latest in Cryo Central

Magnets

From “Superconductivity: Present and Future Applications” by the Coalition for the Commercial Application of Superconductors. Particle physics uses accelerators to recreate the conditions of the early universe in an attempt to piece together the complex puzzle of how we got to where we are today. These huge machines are used...

Energy Storage

From “Superconductivity: Present and Future Applications” by the Coalition for the Commercial Application of Superconductors. With power lines increasingly congested and prone to instability, strategic injection of brief bursts of real power can play a crucial role in maintaining grid reliability. Small-scale Superconducting Magnetic Energy Storage (SMES) systems, based on...

Astronomy

ASTRONOMY IN SPACE by Peter V. Mason, retired, Jet Propulsion Laboratory, and Visiting Associate, California Institute of Technology. Pmason@alumni.caltech.edu In thinking about the reasons to perform astronomy in space, we first consider the effect of the earth’s atmosphere. On a scale of decreasing energy, gamma rays, cosmic rays, X-rays and...

Cryocoolers

What is a Cryocooler? A mechanism that can extract heat from an object (cooler) and by doing so draw its temperature down below approximately 150 Kelvin (cryo). — (Courtesy Dr. Willy Gully) What is the difference between a Cryocooler and a Cryostat? A cryostat is any device designed to maintain...

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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