ADVERTISEMENT

World record quality factor achieved at Fermilab

Earlier this year, Fermilab scientist Anna Grassellino began researching past successes and failures of accelerator cavities made of bulk-diffused niobium-nitride. Scientists reported less-than-stellar results in their tests in the 1990s and, in the years since, appeared to have mostly abandoned the material as a possibility for superconducting cavities. But Grassellino...

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.

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...

ADVERTISEMENT

Cold Compressors

A common way to provide cooling below the normal boiling point of helium (4.2K) is to reduce the pressure above the bath of liquid helium, thus also reducing the bath’s equilibrium saturation temperature. For example, to produce a 1.8K bath of liquid helium, the saturation pressure has to be reduced...

Kapitza Conductance

Kapitza conductance refers to the heat transfer between a solid surface and a fluid that covers that surface. Fundamentally, it describes the inherent difficulty in transferring energy from a solid to the fluid covering the solid surface. This phenomenon was first observed by P. L. Kapitza in 1941 while studying...

Thermosyphons

A thermosyphon (or thermosiphon) is a device that transfers heat via natural convection in a fluid. The natural convection is driven by gravity with the colder, denser fluid flowing downhill and the warmer, less dense fluid flowing back up. Thus, thermosyphons connect an object to be cooled with a reservoir...

Magnetic Levitation

From http://www.superconductors.org. Magnetic-levitation is an application where superconductors perform extremely well. Transport vehicles such as trains can be made to “float” on strong superconducting magnets, virtually eliminating friction between the train and its tracks. Not only would conventional electromagnets waste much of the electrical energy as heat, they would have...

Superconductivity

From Superpower website. History of Superconductivity Superconductivity was discovered in 1911 by the Dutch physicist, Heike Kammerlingh Onnes when he was able to liquefy helium by cooling it to 4 Kelvin, or -452°F. This enabled him to cool other materials close to absolute zero and investigate their electrical properties. He...

Medical Applications of Cryogenics

Neutron Therapy Cryogenics is at the heart of nuclear accelerators. Accelerators such as Fermilab’s Tevatron make neutron therapy for cancer possible. From Fermilab Today 4/20/09: Fermilab currently offers neutron therapy. But staff at Fermilab designed and built the proton accelerator used by the nation’s first hospital-based treatment center to use...

Nuclear Physics

Al Zeller National Superconducting Cyclotron Lab (NSCL) at Michigan State University zeller@nscl.msu.edu Cryogenics has a long history in nuclear physics. The technology has its origins in the use of cold traps for maintaining a vacuum, which is required to prevent beam loss and for generating high voltages used in acceleration....

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...