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    Chapter

    Performance Testing of a Lightweight, High Efficiency Cooler

    A lightweight, high efficiency cryocooler has been tested. The design operating point of the cooler is 10 W at 95 K with a rejection temperature of 300 K, and the goal is a 10 yr operating lifetime. The cooler...

    L. J Salerno, P Kittel, B. P. M Helvensteijn, A Kashani in Cryocoolers 12 (2003)

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    Chapter

    New Regenerator Materials for Use in Pulse Tube Coolers

    A two-stage pulse tube cooler driven by a linear compressor is being developed to provide cooling at 20 K. The first stage of the cooler will have the conventional stainless steel screen regenerator matrix. Th...

    A. Kashani, B. P. M. Helvensteijn, P. Kittel, K. A. Gschneidner Jr.… in Cryocoolers 11 (2002)

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    Chapter

    Measuring Thermal Conductivity of Insulators at Cryogenic Temperatures

    Traditionally, launch vehicles have consisted of a structure containing the vehicle engines, propellant tanks, and electronics. NASA’s next generation of space transportation vehicles is planned to utilize the...

    B. P. M. Helvensteijn, L. J. Salerno, P. R. Roach… in Advances in Cryogenic Engineering (2000)

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    Chapter

    Pressure Drop over Regenerators in Oscillating Flow

    Modeling the performance of pulse tube coolers and stirling coolers involves estimating the pressure drop over the regenerator. Such pressure drop estimates are generally based on steady flow correlations whic...

    B. P. M. Helvensteijn, A. Kashani, A. L. Spivak… in Advances in Cryogenic Engineering (1998)

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    Chapter

    Performance of a Magnetic Refrigerator Operating between 2 K and 10 K

    A prototype of an adiabatic demagnetization refrigerator (ADR) designed for space applications, operating between 2 K and 10 K, has been built and tested. The refrigerant for the ADR consists of thick slices o...

    A. Kashani, B. P. M. Helvensteijn, F. J. McCormack… in Advances in Cryogenic Engineering (1996)

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    Chapter

    Efficiency Calculations for a Magnetic Refrigerator Operating between 2 K and 10 K

    An adiabatic demagnetization refrigerator (ADR) operating between 2 K and 10 K has been built and tested. The refrigerant in the ADR is Gadolinium Gallium Garnet (GGG). Absorption of heat at 2 K and heat rejec...

    B. P. M. Helvensteijn, A. Kashani, P. Kittel in Advances in Cryogenic Engineering (1996)

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    Chapter

    Development of a Magnetic Refrigerator Operating between 2 K and 10 K

    A prototype adiabatic demagnetization refrigerator (ADR) operating between 2 K and 10 K has been built and tested. The refrigerant for the ADR is Gadolinium Gallium Garnet (GGG). In the design thick slices of ...

    A. Kashani, B. P. M. Helvensteijn, F. J. McCormack, A. L. Spivak… in Cryocoolers 8 (1995)

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    Chapter

    Metastable Heat Flow Phenomena and Droo** Pressure Differences in He II Using Multiple Channel Configurations

    Superheating of liquid helium from the He II phase up to 3.0 K is demonstrated in one dimensional multiple channel configurations at pressures below the lamda point pressure. The individual channels have diame...

    B. P. M. Helvensteijn, S. W. Van Sciver in Advances in Cryogenic Engineering (1988)

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    Chapter

    Heat Flow in He II in Microbore Channels

    This paper reports measurements of the pressure and temperature differences as a function of heat flux over the length of glass microbore tubing containing He II. At low heat fluxes the fluid shows a laminar f...

    B. P. M. Helvensteijn, S. W. Van Sciver in Advances in Cryogenic Engineering (1984)