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...
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...
Suppliers of regenerator materials
I was looking for suppliers of regenerator materials. Can you please provide a list of vendors for: • Lead spheres • Bronze screen discs • Rare earth materials and spheres Thank you in advance for any help you can provide.
Containing ice accumulation while recovering helium
We are implementing a system to recover helium from our Janis ST-500 continuous flow LHe cryostat. The recovery system uses standard 1/4″ plastic tubing, which we connect directly to the cryostat’s exhaust port. The problem with this setup is that the gas is still quite cold as it leaves the...
Looking for some advice regarding cryogenic modeling in ANSYS FEA software
I am looking for some advice regarding cryogenic modeling in ANSYS FEA software. I have been trying to use the Transient Thermal module, in workbench 14.5, to model the cooling of a device in a dilution fridge. I have approximate values for the cooling power of each plate in the...
Compensators and/or accumulators: Are they used in cryogenics?
Are compensators and/or accumulators, high or low pressure, used in cryogenics? Are they used in space?