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Search Publications by: Peter Bradley (Fed)

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Displaying 51 - 75 of 79

Effect of Component Geometry on Flow Nonuniformities in a Large Pulse Tube Cryocooler

May 17, 2010
Author(s)
Michael A. Lewis, Ryan P. Taylor, Ray Radebaugh, Peter E. Bradley
A single-stage pulse tube cryocooler was designed to achieve 50 W of refrigeration power at 50 K when driven by a pressure oscillator that can produce up to 2.8 kW of acoustic power at 60 Hz. Initial experimental data produced no-load temperatures that

Mixed Refrigerants for a Glass Capillary Micro Cryogenic Cooler

April 24, 2010
Author(s)
Mu Hong Lin, Peter E. Bradley, Marcia L. Huber, Ryan J. Lewis, Ray Radebaugh, Yung-Cheng Lee
Optimized mixed refrigerants are applied in Joule-Thomson (JT) micro cryogenic coolers (MCC) to enhance efficiency. Mixed refrigerants deliver equivalent refrigeration power with much lower pressure ratio and flow rate compared to pure nitrogen refrigerant

Investigation of Flow Nonuniformities in a Large 50 K Pulse Tube Cryocooler

June 28, 2009
Author(s)
Michael A. Lewis, Ryan P. Taylor, Ray Radebaugh, Isaac Garaway, Peter E. Bradley
A single stage pulse tube cryocooler was optimized to provide 50 W of net refrigeration power at 50 K when driven by a pressure oscillator that can produce up to 2.8 kW of acoustic power at 60 Hz. The cryocooler was designed with the ability to provide

DESIGN, FABRICATION, AND ASSEMBLY OF A HOLLOW-CORE FIBER-BASED MICRO CRYOGENIC COOLER

June 21, 2009
Author(s)
James C. Booth, Mu Hong Lin, Peter E. Bradley, H.-j Wu, Ray Radebaugh, Y.C. Lee
One of the smallest Joule Thomson (J-T) micro cryogenic coolers (MCC) utilizing a hollow-core fiberbased heat exchanger (HX) is designed, fabricated, assembled and tested. Techniques that control mask material etching are developed to fabricate a multi

Pulse Tube Cryocooler for Rapid Cooldown of A Superconducting Magnet

June 9, 2008
Author(s)
Michael A. Lewis, Ryan P. Taylor, Peter E. Bradley, Isaac Garaway, Ray Radebaugh
A single-stage pulse tube cryocooler was designed to provide rapid cooldown of a high temperature superconducting (HTS) magnet that is part of a gyrotron required for the generation of a high-power mm-wave (95 GHz) beams. These beams are used in the

Impedance Measurements of Inertance Tubes at High Frequency and Pressure

July 16, 2007
Author(s)
Michael A. Lewis, Ryan P. Taylor, Peter E. Bradley, Ray Radebaugh, Gershon Grossman, Zhihua Gan
Previous comparisons between measured and calculated inertance tube impedance were made at frequencies below 70 Hz and average pressures below 3 MPa. In this paper, we present results on similar comparisons for frequencies up to 150 Hz and average

Cryogenic Technologies Group Website

June 11, 2007
Author(s)
Marilyn R. Yetzbacher, Peter E. Bradley
Revised website of Information pertaining to the Cryogenics Group. Provides general information, staffing, contact information, articles and publications relative to the subject of cryogenics and cryogenic coolers and their applications. Of a more

Characterization of Inertance Tubes Using Resonance Effects

June 14, 2006
Author(s)
Michael A. Lewis, Peter E. Bradley, Ray Radebaugh, Zhihua Gan
Inertance tubes can be characterized by their inertance, compliance, and resistance. All three of these impedance components are present during normal measurements of inertance tube impedance. As a result, in comparing experimental results with models it

Proposed Rapid Cooldown Technique for Pulse Tube Cryocoolers

June 14, 2006
Author(s)
Ray Radebaugh, Agnes O?Gallagher, Michael A. Lewis, Peter E. Bradley
Some cryocooler applications, such as those for military operations dealing with high temperature superconducting (HTS) magnets, motors, or generators, require faster cooldown times than what can normally be provided with a cryocooler designed to

Evaluation of Pressure Oscillator Losses

August 29, 2005
Author(s)
Peter E. Bradley, Michael A. Lewis, Ray Radebaugh
Efficiencies of regenerative cryocoolers are influenced by losses within the pressure oscillator (compressor). An evaluation of these losses is important when searching for ways to improve the overall cryocooler efficiency. Typically, compressor efficiency

Impedance Measurements of Inertance Tubes

August 29, 2005
Author(s)
Michael A. Lewis, Peter E. Bradley, Ray Radebaugh
The flow impedance of an inertance tube 5.74 mm inside diameter and 2.36 m long coupled to various reservoir volumes was measured and compared with that predicted by a model based on a transmission line analogy. Though data at other average pressures and