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

Boiloff Calorimetry for the Measurement of Very Low Heat Flows

The use of boiloff calorimetry to measure the effects of thermal energy (or heat) dates back to the early 1900s [1, 2]. Gas flow rates measured in evaporation—or boiloff—calorimetry enable direct calculation of quantities such as heat flux and thermal conductivity. A particularly useful approach is to use nitrogen for...

Remembering the 1987 Woodstock of Physics

Paul Michael Grant was in the room where it happened, and in this essay, he recalls the 1987 APS March Meeting known as the "Woodstock of Physics." It began when Brian Maple, of UC San Diego, took the unprecedented and ambitious step of assembling an “off the program” all night...

Women in Cryogenics and Superconductivity

CSA celebrates women in cryogenics and superconductivity. In this feature, six women in positions across the industry discuss current projects, how they entered the field and their thoughts on attracting more women to the profession.

Cryogenic Sapphire Oscillator Enhancement Improves Accuracy

Researchers from the University of Adelaide in South Australia have enhanced the Cryogenic Sapphire Oscillator, or Sapphire Clock, to allow time measurements with accuracy on the femtosecond scale. The oscillator has a five-centimeter cylinder-shaped sapphire crystal cooled to about -267°C, or about five or six degrees above absolute zero. At...

The Robots of CERN

The LHC contains 120 tons of liquid helium kept at 1.9 K. And even with safety systems in place, engineers there prefer to limit underground access when the cryogenic systems are activated. Enter TIM—the Train Inspection Monorail. TIM is a chain of wagons, sensors and cameras that snake along a...

NASA Telescope Reveals Batch of Earth-size, Habitable-zone Planets around Single Star

NASA's Spitzer Space Telescope has revealed a new exoplanet discovery: the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.

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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