ADVERTISEMENT

James Webb mirror segments cryogenically tested at Marshall SFC

The first six of 18 segments that will form NASA's James Webb Space Telescope's primary mirror for space observations have begun final round-the-clock cryogenic testing at the X-ray and Cryogenic Facility at NASA's Marshall Space Flight Center, Huntsville AL.

John Baust elected president of American College of Cryosurgery

Dr. John Baust, UNESCO Professor and Director of the Institute of Biomedical Technology at SUNY's Binghamton University, has been elected President of the group, which promotes the highest possible standards in clinical practice, continuing education and research in cryosurgery, raising public awareness in the uses of cryosurgery, and providing a...

ADVERTISEMENT

Dewar

A dewar is a type of cryostat named after Sir James Dewar, the researcher who first developed the concept of a vacuum insulated container with silvered walls to reflect thermal radiation. Dewar was the first to liquefy hydrogen, and he created the device to store his discovery. The thermos bottle...

Stirling and Gifford-McMahon Cryocoolers

Stirling and Gifford-McMahon (GM) cryocoolers are two of the most commonly used cryocoolers in cryogenics. Both devices have a significant industrial base and operate at a wide range of temperatures and capacities. The thermodynamic cycles for both of these cryocoolers are quite similar. The Stirling cycle consists of a compressor,...

Liquefied Natural Gas (LNG)

A significant commercial application of cryogenics is the liquefaction, transport and storage of natural gas. Liquefied Natural Gas (LNG) is generally 95 percent methane with a few percent ethane and much lower concentrations of propane and butane. LNG liquefies at 111.6 K. Unlike many applications of cryogenics, the motivation for...

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...

In search of a calculation for designing a cryostat

I am a final year physics student at the University of Birmingham, and as part of a group I am currently designing a cryostat. One of the calculations I need to make (very soon!) is how much heat will be conducted down the walls. All information I have found so...

Safety of ethylene glycol and pressurized oxygen

We are reviewing the product design of liquid filled differential level gauges and want to insure that they meet the industry requirements. The former license owner had authorized that a fill fluid of ethylene glycol (68%) and distilled water (32%) could be used for oxygen service up to 500 psi....