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FAST Research Accelerator Reaches Design Beam Energy

In May, Fermilab sent an electron beam with an energy of 50 million electronvolts, or MeV, through the photoinjector at the Fermilab Accelerator Science and Technology facility (FAST), achieving a major design goal for the accelerator and marking the beginning of a new accelerator science program at the laboratory.

New Elements Named, Public Comment Sought

The International Union of Pure and Applied Chemistry (IUPAC) has opened a five-month long public comment and review period of the names recommended for elements 113, 115, 117 and 118, the discoveries of which were announced late last year.

Scientists Use Frozen Argon to Boost Laser Light to New Extremes

Researchers at the Department of Energy’s SLAC National Accelerator Laboratory, Stanford University and Louisiana State University have achieved a dramatic high harmonic generation (HHG) shift by shining an infrared laser through argon gas that’s been frozen at 20 K into a thin, fragile solid whose atoms barely cling to each...

New Low-Defect Method to Nitrogen Dope Graphene Results in Tunable Bandstructure

An interdisciplinary team of scientists at the US Naval Research Laboratory (NRL) Electronics Science and Technology and Materials Science and Technology Divisions has demonstrated hyperthermal ion implantation (HyTII) as an effective means of substitutionally doping graphene—a hexagonally-arranged single-atomic thickness carbon sheet—with nitrogen atoms. The result is a low-defect film with...

SLAC Testing Prototype Dark Matter Detector

Prototyping of a new, ultrasensitive “eye” for dark matter is making rapid progress at the Department of Energy’s SLAC National Accelerator Laboratory, according to researchers and engineers who have installed a small-scale version of the future LUX-ZEPLIN (LZ) detector to test, develop and troubleshoot various aspects of its technology. When...

Spinning Electrons Yield Positrons for Research

Using the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) (CSA CSM), a team of researchers has, for the first time, demonstrated a new technique for producing polarized positrons. The method could enable new research in advanced materials and offers a new avenue...

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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....

Magnets

From “Superconductivity: Present and Future Applications” by the Coalition for the Commercial Application of Superconductors. Particle physics uses accelerators to recreate the conditions of the early universe in an attempt to piece together the complex puzzle of how we got to where we are today. These huge machines are used...

Energy Storage

From “Superconductivity: Present and Future Applications” by the Coalition for the Commercial Application of Superconductors. With power lines increasingly congested and prone to instability, strategic injection of brief bursts of real power can play a crucial role in maintaining grid reliability. Small-scale Superconducting Magnetic Energy Storage (SMES) systems, based on...

Astronomy

ASTRONOMY IN SPACE by Peter V. Mason, retired,  Jet Propulsion Laboratory, and Visiting Associate, California Institute of Technology. Pmason@alumni.caltech.edu In thinking about the reasons to perform astronomy in space, we first consider the effect of the earth’s atmosphere.  On a scale of decreasing energy, gamma rays, cosmic rays, X-rays and...

Cryocoolers

What is a Cryocooler? A mechanism that can extract heat from an object (cooler) and by doing so draw its temperature down below approximately 150 Kelvin (cryo). — (Courtesy Dr. Willy Gully) What is the difference between a Cryocooler and a Cryostat? A cryostat is any device designed to maintain...

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...