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Space Cryogenics: The ECOSTRESS Instrument After Four Years in Space

The instrument is approaching four years of operation in space, with its over- all thermal performance as predicted and no changes to cryocooler performance. To date, all three cryocoolers have accumulated over 32,000 operating hours. On the 210th day after the initial power-on, a fault condition was detected, and the...

The Cold Facts of the Spitzer Space Telescope

NASA’s Spitzer Space Telescope, launched in August 2003 and decommissioned in January 2020 after more than 16 glorious years of exploration of the universe at infrared wavelengths, was a technical and scientific marvel. Infrared astronomical studies at wavelengths longward of 1 micron, somewhat beyond the limit of human vision at...

Another Primary Webb Space Telescope Instrument Gets the “Go for Science”

Recently, NIRISS, one of NASA’s James Webb Space Telescope’s four primary scientific instruments concluded its postlaunch preparations and was declared ready for science. Now a second of Webb’s four primary scientific instruments, known as the Mid-Infrared Instrument (MIRI), has also concluded its postlaunch preparations and is now ready for science. MIRI’s coronagraphic imaging...

Physicists Find a Shortcut to Seeing an Elusive Quantum Glow

Theoretical physics is full of weird and wonderful concepts: wormholes, quantum foam and multiverses, just to name a few. The problem is that while such things easily emerge from theorists’ equations, they are practically impossible to create and test in a laboratory setting. But for one such “untestable” theory, an...

NASA’s Webb Delivers Deepest Infrared Image of Universe Yet

NASA’s James Webb Space Telescope has delivered the deepest and sharpest infrared image of the distant universe so far. Webb’s First Deep Field is galaxy cluster SMACS 0723, and it is teeming with thousands of galaxies – including the faintest objects ever observed in the infrared.  Webb’s image is approximately...

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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...

Magnetic Levitation

From http://www.superconductors.org. Magnetic-levitation is an application where superconductors perform extremely well. Transport vehicles such as trains can be made to “float” on strong superconducting magnets, virtually eliminating friction between the train and its tracks. Not only would conventional electromagnets waste much of the electrical energy as heat, they would have...

Superconductivity

From Superpower website. History of Superconductivity Superconductivity was discovered in 1911 by the Dutch physicist, Heike Kammerlingh Onnes when he was able to liquefy helium by cooling it to 4 Kelvin, or -452°F. This enabled him to cool other materials close to absolute zero and investigate their electrical properties. He...

Medical Applications of Cryogenics

Neutron Therapy Cryogenics is at the heart of nuclear accelerators. Accelerators such as Fermilab’s Tevatron make neutron therapy for cancer possible. From Fermilab Today 4/20/09: Fermilab currently offers neutron therapy. But staff at Fermilab designed and built the proton accelerator used by the nation’s first hospital-based treatment center to use...

Nuclear Physics

Al Zeller National Superconducting Cyclotron Lab (NSCL) at Michigan State University zeller@nscl.msu.edu Cryogenics has a long history in nuclear physics. The technology has its origins in the use of cold traps for maintaining a vacuum, which is required to prevent beam loss and for generating high voltages used in acceleration....

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...