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Liquid Helium Ballast Refrigeration

The Need for Vibration-Free Cryogenics The measurement of local gravitational fields requires continuous, high precision and extremely stable measurements. In 1968, the development of the superconducting gravity meter (SG)[1] vastly improved the state of the art. In contrast to mechanical quartz or metal springs, SGs use a superconducting sphere levitated in...

Qubit Measurement Systems Right Out of the Box?

Necessity of mK-Cryogenics-During the past years, advances in both lithography and millikelvin cryogenics have supported and enabled vast improvement in the sophistication of experimental research on electrical circuits that display uniquely quantum mechanical behavior. It comes as no surprise that dilution refrigerator measurement systems have moved beyond basic physics research...

The Development of an AMRR for Sub-Kelvin Cooling of Space Science Instrumentation – ICC21 Best Student Paper Award Recipient

Introduction-Cryogenic detectors have higher sensitivity and better energy resolution than alternative sensors, making them an attractive option for space exploration and essential for observing low energy photons in the near- or far-IR, X-ray and submillimeter ranges.[1] Since NASA’s first cryogenic missions in the early 1980s, increasingly complex space detectors have...

The Next Generation in Cryogenics and Superconductivity

CSA’s annual Young Professionals introduces outstanding engineers, scientists, and technicians (under 40) who are making fascinating contributions to the cryogenics and superconductivity industries. Debuted in the summer of 2006, this spotlight shines on future leaders who show the promise of making a difference in their fields.  We are proud to...

New Green Storage System Offers Renewable Energy On-Demand

Back to the Future movie fans may remember the term “flux capacitor” as a fictional device that allows for time travel. That device still doesn’t exist, but a University of Central Florida storage technology does use a different type of flux capacitor developed by NASA. While trying to find a way...

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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....

Primary Standards

Elie K. Track Hypres, Inc. elie@hypres.com http://www.hypres.com/ Primary standards involve the exact definition and realization of units of measurement for various quantities, time, length, mass, voltage, resistance, current, etc. International agreements based on the latest scientific knowledge define those units, and their realizations vary depending on the unit itself. For...

Shrink Fitting

Robin A. Rhodes Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Shrink fitting, (or “compression fitting” as it is sometimes called), is a method used to insert a pin or bushing into a housing or other assembly requiring an extremely tight tolerance fit. It can be used as an alternative to...

Telecommunications

From the Winter 2004 issue of Cold Facts magazine The recent M-Calc IV — 4th Industry Assessment workshop discussing military and commercial applications for low-cost cryocoolers, held in November in San Diego, highlighted progress being made in cryogenics as applied in telecommunications. The reliability and long lifetime of projects now...

Wind Tunnels

Dr. Robert Kilgore The development of the cryogenic wind tunnel is one of many significant breakthroughs in both cryogenics and wind-tunnel technology made during the past millennium. Interest in the development of high-speed commercial and military aircraft resulted in a review of problems of flow simulation in transonic wind tunnels...

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...