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Analyzing Transcritical CO2 Compression and Pumping Pathways

Supercritical carbon dioxide exhibits anomalous behavior in the vicinity above the critical point. The Irish physical chemist Thomas Andrews (1863) was the first who studied the supercritical behavior of carbon dioxide. He explained his observations of the fluid state above the critical point as follows: “…the surface of demarcation between the...

AVCO Sets its Sights on Mars

“You’re Going to The Moon” should now be quoted as “You’re Going to Mars.” From the 1990s downturn in the aerospace industry to today’s exponential growth, the demand for precision flow control and flow measurement has continued to follow the same growth trajectory. The focus of Alloy Valves and Control...

CCAT Observatory Approaches First Light

For the past six years, CCAT Observatory Inc., a nonprofit research organization formed by more than a dozen academic institutions led by Cornell University, has been developing a new telescope, the Fred Young Submillimeter Telescope (FYST, pronounced “feast”) and its supporting infrastructure to observe at submillimeter wavelengths. The infrastructure is...

Goddard Goings: Insight Into Its Past, Present and Future

James Webb Space Telescope-“I’m Back in the Saddle Again!” – It’s likely anyone reading this article has heard about the James Webb Space Telescope (JWST). The telescope launched on December 25, 2021 (EST) with much fanfare. Over the next month, it traveled to its observation location at the L2 Lagrange...

NASA Completes Heart of Roman Space Telescope’s Primary Instrument

The heart of NASA’s Nancy Grace Roman Space Telescope was recently delivered to Ball Aerospace in Boulder, Colo., for integration into the Wide Field Instrument (WFI). Called the Focal Plane System (FPS), it serves as the core of Roman’s camera. When the mission launches by May 2027, astronomers will use...

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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....

Cryogenic Electronics

Randall Kirschman, consulting physicist, Mountain View, California ExtElect@gmail.com Cryogenic electronics—the operation of electronic devices, circuits, and systems at cryogenic temperatures—has been a valuable technology for decades. Cryogenic electronics (also referred to as low-temperature electronics, or cold electronics) can be based on semiconductive devices, on superconductive devices, or on a combination...

Particle Physics: High Energy Physics

Cryogenics and High-Energy Physics 1. From symmetry magazine: http://www.symmetrymagazine.org/cms/?pid=1000627: Cryogenics is the study of how materials behave at temperatures near absolute zero. In high-energy particle accelerators, such frigid temperatures reduce the electrical resistance of wires in superconducting magnets, increasing the magnet strength and allowing faster particle acceleration. The same holds...

HTS Degaussing Systems

From the Spring 2009 issue of Cold Facts (Volume 25, Number 2): Thanks to a joint project by the US Navy and a number of industry partners, high temperature superconducting (HTS) technology is now at the heart of an advanced degaussing system aboard the USS Higgins at the naval station...

Magnetic Resonance Imaging

From http://www.superconductors.org: An area where superconductors can perform a life-saving function is in the field of biomagnetism. Doctors need a non-invasive means of determining what’s going on inside the human body. By impinging a strong superconductor-derived magnetic field into the body, hydrogen atoms that exist in the body’s water and...

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...