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Search Publications by

Ray Radebaugh (Assoc)

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Displaying 1 - 25 of 82

Compact 2.2 K Cooling System for Superconducting Nanowire Single Photon Detectors

January 25, 2017
Vincent Y. Kotsubo, Ray Radebaugh, Sae Woo Nam, Joel N. Ullom, Brandon L. Wilson, Paul Hendershott, Micheal Bonczyski
We are developing a compact, low power, closed cycle cooling system for Superconducting Nanowire Single Photon Detectors. The base temperature of the present prototype, which uses a helium-4 Joule-Thomson stage, is 2.2 K with over 1.2 mW of cooling. This

Chapter 1: Introduction to low temperatures materials and mechanisms

August 19, 2016
Ray Radebaugh
Operating at cold temperatures is essential to many processes in numerous fields of science and engineering including refrigeration, space exploration, electronics, physics, chemistry, thermodynamics, and medicine. Increasingly, there is a growing interest

Design and Analysis of a 150 K Cascade Joule-Thomson Microcooler

June 9, 2014
Ray Radebaugh, Peter E. Bradley, Collin J. Coolidge, Ryan J. Lewis, Y.C. Lee
Lightweight and compact microcoolers are needed for advanced, hand-held infrared systems. A temperature of 150 K is adequate for high sensitivity with some of the latest IR detectors, which simplifies the cooling requirements compared to 80 K detectors

A Half Century of Cryogenics and CSA

May 5, 2014
Ray Radebaugh
1964 seems just like yesterday to me, yet it was 50 years ago. The Cryogenic Society of America (CSA) was born that year, and I was just beginning my professional career in cryogenics. Because I have been active in cryogenics for all these past 50 years, I

Properties of Selected Materials at Cryogenic Temperatures

June 17, 2013
Peter E. Bradley, Ray Radebaugh
The design of systems for operation at cryogenic temperatures requires the use of material properties at these low temperatures. The properties at cryogenic temperatures can be much different than the room-temperature values. In addition, some properties

Experimental investigation of Low-pressure refrigerant mixtures for Micro Cryogenic Coolers

February 4, 2013
Ryan J. Lewis, Yunda Wang, Peter E. Bradley, Marcia L. Huber, Ray Radebaugh, Y. C. Lee
Micro Cryogenic Coolers (MCCs) can achieve very small sizes and high efficiencies when operating with a refrigerant mixture, but micro-scale compressors have a limited pressure output. Four refrigerant mixtures were designed to operate between 0.4 MPa and

Development of a 4K Regenerator and Pulse Tube Test Facility

October 10, 2012
Michael A. Lewis, Peter E. Bradley, Ryan P. Taylor, Ray Radebaugh
Recent advances in superconducting electronic systems are requiring larger envelopes for cooling power, efficiency, and operational environments from commercial based cryogenic cooling systems. One such system targeted at meeting these requirements is the

Verification of the Back-EMF Method for Piston Velocity Measurements

July 10, 2012
Ray Radebaugh, Michael A. Lewis, Peter E. Bradley
Linear compressors are used to drive pulse tube or Stirling cryocoolers, and they can be used as expanders in place of inertance tubes when inertance tubes cannot provide sufficient phase shifts between flow and pressure. Commercial linear compressors


November 17, 2011
Ryan J. Lewis, Mu Hong Lin, Yunda Wang, Jill Cooper, Peter E. Bradley, Ray Radebaugh, Marcia L. Huber, Yung-Cheng Lee
Joule-Thompson (J-T) based micro cryogenic coolers (MCCs) are attractive because they can provide the cryogenic temperatures needed for small electronic devices while having a low cost and small volumetric footprint. A compressor is a major part of a

Cryocoolers for Aircraft Superconducting Generators and Motors

June 13, 2011
Ray Radebaugh
The proposal by NASA to use high temperature superconducting (HTS) generators and motors on future (2035) aircraft for turboelectric propulsion imposes difficult requirements for cryocoolers. Net refrigeration powers of about 5 kW to 10 kW at 50 K to 65 K

Experiments with Linear Compressors for Phase Shifting in Pulse Tube Cryocoolers

June 13, 2011
Michael A. Lewis, Peter E. Bradley, Ray Radebaugh
For the past year NIST has been investigating the use of mechanical phase shifters as warm expanders for pulse tube cryocoolers. Unlike inertance tubes, which have a limited phase shifting ability at low acoustic powers, mechanical phase shifters have the

Micro Cryogenic Coolers for IR Imaging

April 29, 2011
Ryan J. Lewis, Yunda Wang, Jill Cooper, Mu Hong Lin, Victor M. Bright, Yung-Cheng Lee, Peter E. Bradley, Ray Radebaugh, Marcia L. Huber
Joule-Thomson micro cryogenic coolers (MCCs) are a preferred approach for small and low power cryocoolers. With the same heat lift, MCC's power input can be only 1/10 of a thermoelectric cooler's input, and MCC's size can be only 1/10 of a Stirling cooler

Model for Transient Behavior of Pulse Tube Cryocooler

January 1, 2011
Gershon Grossman, Peter E. Bradley, Michael A. Lewis, Ray Radebaugh
This article describes an investigation of the transient behavior of a small (2.0 W at 85 K) Pulse Tube cryocooler operating at 120 Hz with an average pressure of 3.5 MPa, capable of relatively fast cool-down to about 60 K. In a series of experiments, the

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

May 17, 2010
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
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

Development of Miniature, High Frequency Pulse Tube Cryocoolers

April 5, 2010
Ray Radebaugh, Isaac Garaway, Alexander Veprik
Because acoustic power density is proportional to frequency, the size of pulse tube cryocoolers for a given refrigeration power can be reduced by operating them at higher frequencies. A frequency of about 60 Hz had been considered the maximum frequency