Two new senior staff scientists appointed at SLAC
The leader of SLAC's involvement in the Cryogenic Dark Matter Search and an instrument scientist with the Linac Coherent Light Source X-ray laser have been appointed senior staff scientists at SLAC.
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CGA announces the 5th edition of the Handbook of Compressed Gases
The fifth edition of the CGA's Handbook of Compressed Gases has been significantly revised with expanded content, updated regulatory and technical information, and color graphs and figures to meet the needs of today's compressed gas industry.
Cryogenic Dark Matter Search adds new intrigue with the latest result
Physicists operating an experiment located half a mile underground in Minnesota reported that they have found possible hints of dark-matter particles. The Cryogenic Dark Matter Search experiment has detected three events with the characteristics expected of dark matter particles, MIT graduate student Kevin McCarthy reported at the American Physical Society...
Teamwork celebrated at ITER Conductor Meeting
In pre-ITER times, the world production of niobium-tin (Nb3Sn) strands did not exceed 15 tons per year. Discovered in 1954, this intermetallic compound that exhibits a critical temperature of ~18 K and is able to withstand intense magnetic fields was used mainly in high field coils and nuclear magnetic resonance...
New “Ask the Experts” question: Problem sending LN2 through hoses – need to minimize heat leak
Help this person solve his problem with heat leak in two hoses of different lengths.
Problem sending LN2 through hoses – need to minimize heat leak
We use liquid nitrogen at our power station to freeze light and heavy water in piping. The ice plug formed within the piping acts as a “valve” and allows us to work on a section of the piping system that otherwise cannot be isolated. The liquid nitrogen enters a jacket...
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Helium-3
Helium-3 (3He) is one of the two stable isotopes of helium. The other is the much more common Helium-4 (4He). Neither of these isotopes should be confused with He II, which is the second liquid phase of 4He. He II was discussed in this column in the Spring 2010 edition...
Cryopumping
Cryopumping refers to the use of cryogenic temperatures to produce vacuum in enclosed spaces. More broadly, it can also refer to the removal of gases via cryogenic temperatures from a flow stream or enclosure without necessarily resulting in vacuum pressures. This is an important application of cryogenics and is used...
Thermal Acoustic Oscillations
Thermal Acoustic Oscillations (TAO) are a common event in cryogenic systems that can have significant adverse effects on the performance of the system. TAOs are sustained pressure oscillations that can occur in tubes containing gas, closed at one end (the warm end) that have a very large temperature gradient along...
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...
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...
Separated layers of ice over a pipe
I want to know that why there are different layers of ice over a pipe carrying a cryogenic fluid, each layer separated with clear marks / lines? What do these layers signify?