First room-temperature maser developed
British researchers have, for the first time, built a prototype solid-state maser that works at room-temperature, with no permanent applied magnetic field.
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Estimating cost for components of a helium plant
I have to perform a cost estimation of our helium cryogenic plant design. I based it on the formula discussed in the following article “THE COST OF HELIUM REFRIGERATORS AND COOLERS FOR SUPERCONDUCTING DEVICES AS A FUNCTION OF COOLING AT 4 K” by M. A. Green: C(M$) = 2.6 [R(kW)]^0.63...
How much heat energy does LN2 contain per lb.?
I would like to know how much heat energy liquid nitrogen contains per lb. In other words, per lb. of liquid, how many BTUs of heat would N2 absorb in the process of coming up to about 60F? I want to capture the cold energy of nitrogen as it vaporizes...
Software for thermophysical properties of helium down to 1K
What are the options when it comes to software for thermophysical properties of helium at temperatures down to 1K? I know Hepak – is it still the most commonly used package?
Refilling process of a helium cryogenic plant
I’m trying to collect some information about the refilling process of a helium cryogenic plant. Due to the physiologic losses I expect to have to foreseen a periodic refilling of helium. Our plant will be characterized by a refrigerator/liquefactor. A control cryostat with 4.5 K LHe coming from the liquefactor...
What's the best gas to use for pulse GMAW?
I have a 78″ ID vessel, 3/8″ thick shells, ½” heads, from SA-240-304L, which will have an ASME U-Stamp and I am planning on sub-arcing the seams and using pulse GMAW (ER308L for both) for the nozzles. I am comfortable with the SAW, but I am wondering about the best...
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Dewar
A dewar is a type of cryostat named after Sir James Dewar, the researcher who first developed the concept of a vacuum insulated container with silvered walls to reflect thermal radiation. Dewar was the first to liquefy hydrogen, and he created the device to store his discovery. The thermos bottle...
Stirling and Gifford-McMahon Cryocoolers
Stirling and Gifford-McMahon (GM) cryocoolers are two of the most commonly used cryocoolers in cryogenics. Both devices have a significant industrial base and operate at a wide range of temperatures and capacities. The thermodynamic cycles for both of these cryocoolers are quite similar. The Stirling cycle consists of a compressor,...
Liquefied Natural Gas (LNG)
A significant commercial application of cryogenics is the liquefaction, transport and storage of natural gas. Liquefied Natural Gas (LNG) is generally 95 percent methane with a few percent ethane and much lower concentrations of propane and butane. LNG liquefies at 111.6 K. Unlike many applications of cryogenics, the motivation for...
Food Processing
Cryogenics and Food The industrial gas industry provides a host of products and services related to food. The various gases have useful and sometimes fascinating applications in food industry. “The food industry is not a homogenous industry. The needs of customers processing hamburger vs. poultry vs. strawberries vs. seafood, for...
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...
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?