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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...

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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...

History of Cryogenics

From the Fall 1999 issue of Cold Facts magazine Millennium Breakthroughs A variety of CSA members give different perspectives on the past millennium: What were the most significant breakthroughs in cryogenics during the past millennium? Prof. R.G. Scurlock, Kryos Technology, scurlock@soton.ac.uk (“Breakthrough” = way through obstacles — Oxford English Dictionary)...

Cryobiology

Andreas Sputtek Past President Society for Cryobiology sputtek@uke.uni-hamburg.de or http://www.sputtek.de/. The word cryobiology (from the Greek words “cryo” = cold, “bios” = life, and “logos” = science) literally signifies the science of life at low temperatures. In practice, this field comprises the study of any biological material or system (e.g.,...

Cryogenic Insulation

James E. Fesmire Cryogenics Test Laboratory NASA Kennedy Space Center james.e.fesmire@nasa.gov Introduction In today’s world, the use of cryogenics and low-temperature refrigeration is taking a more and more significant role. From the food industry, transportation, energy, and medical applications to the Space Shuttle, cryogenic liquids must be stored, handled, and...

Cryogenic Treatment of Materials

F.J. Diekman Controlled Thermal Processing, Inc. info@metal-wear.com Cryogenic Processing (also called cryogenic treatment, and incorrectly “cryogenic tempering”) is a process that uses cryogenic temperatures to modify materials to enhance their performance. Cryogenic Processing involves the slow reduction in temperature of the material to at least -300°F (-185°C) and holding the...

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...