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Cooling LSST, the World’s Largest Digital Camera

When it’s ready in 2022, LSST will image almost all of the sky visible from its vantage point on a Chilean mountain, Cerro Pachón, every few nights for a decade to make an astronomical “movie” of unprecedented proportions. To keep the camera cold enough, engineers needed to create a customized...

Ultracold Atoms Could Provide 2D Window to Exotic 1D Physics

In a recent paper in Physical Review Letters, Matthew Foster and Seth Davis, theoretical physicists at Rice University, proposed an experiment to measure fractionalization not in electrons but in atoms so cold they follow the same quantum rules that dictate how electrons behave in quantum materials—a growing class of materials...

LIGO and Virgo Detect Neutron Star Smash-Ups

On April 25, the National Science Foundation's Laser Interferometer Gravitational-Wave Observatory (LIGO) and the European-based Virgo detector registered gravitational waves from what appears likely to be a crash between two neutron stars—the dense remnants of massive stars that previously exploded. One day later, the LIGO-Virgo network spotted another candidate source...

NASA Taps 11 American Companies to Advance Human Lunar Landers

NASA has selected 11 American companies to conduct studies and produce prototypes of human landers for its Artemis lunar exploration program. This effort will help put American astronauts — the first woman and next man — on the Moon’s south pole by 2024 and establish sustainable missions by 2028. Through...

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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....

Air Separation and Liquefaction

by Nils Tellier, PE, President, EPSIM Corporation (CSA CSM) nils@epsim.us All illustrations courtesy EPSIM Corporation Background History of Air Separation and Liquefaction This section builds on a rich history of methods to develop deep refrigeration and cryogenic liquefaction during the 19th Century. You are encouraged to read Cryo Central’s History...

Bose-Einstein Condensate

A Bose-Einstein condensate, first proposed in 1925 by Albert Einstein based on work done by Satyendra Nath Bose (the same Bose from whom the term boson is derived), is a super-cold state of matter in which almost all of the individual atoms have “condensed” down to the lowest possible quantum...

Cold Technology for Pest Control

While it does not reach temperatures cold enough to be called cryogenic, carbon dioxide snow is at the heart of a new way of dealing with unwanted pests. It utilizes a quick freezing process that takes advantage of the properties of carbon dioxide snow and has a number of benefits...

Cryogenic Finishing

The following 3 articles discuss the uses and procedures of various type of cryogenic finishing. 1) By Robin A. Rhodes, Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Cryogenic Deflashing is employed to remove undesired residual mold flash that remains on molded parts after they are removed or ejected from the...

Seeking recommendations for commercial sensors

I would like to measure vibrations in small LHe cryostats. Could anybody recommend commercial sensors which would be suitable for the purpose? I am interested in the frequency range between 1Hz and a couple of KHz, with particular attention to the low frequency side.

Estimating cost of carbon steel, pure helium storage tanks

In order to perform an indicative cost assessment of our helium cryogenic plant (still in the design phase), I need an estimation of the cost of carbon steel room temperature pure helium storage tanks. The storage pressure is 20 bar. Can anyone give me suggestions about how to estimate the...

Supplier of pressure sensor that works down to 4.2 K

In an actual experiment we would like to measure the static pressure in a cryostat in the range between one and four bar. Therefore we are looking for some (more or less) cheap pressure sensors that work in liquid helium in the pressure range up to five bar. Unfortunately all...

Looking for reference/textbook suggestions

Can you suggest some reference textbooks for practical thermodynamics applications in cryogenic fields? I need textbooks with cryogenics calculations and examples, dimensioning procedures, second principle applications in cryogenics, heat load calculations, cryogenic pump application, etc. Do such books exist? Does any similar source of information exist?