Vibration free cooling of detectors to cryogenic temperatures is critical for many terrestrial, airborne, and space based instruments. Cooling of solids by anti Stokes fluorescence is an emerging refrigeration technology that is inherently vibration free and compact, and enables cooling of small loads to cryogenic temperatures. In this Highlight, advances in laser cooling of solids are discusse...

We demonstrate that high-injection barrier effects associated with the collector-base silicon-germanium (SiGe) to silicon (Si) heterojunction are an important design constraint for SiGe heterojunction bipolar transistors (HBTs) operating at cryogenic temperatures. Due to its thermally activated nature, these barrier effects can have important dc and ac consequences at cryogenic temperatures eve...

Simple methods are presented for handling, mounting, storage and transportation of crystals at cryogenic temperatures. They are easy to learn and have a number of technical and operational advantages over currently popular methods. In particular, the temperature of the crystal throughout all manipulations is known; it is shown never to rise above that of the warmest component of the cryogenic s...

Cryogenic system is one of major cost drivers in high intensity superconducting (SC) continuous wave (CW) accelerators. Thermal radiations coming through the warm-ends of cryomodule and room temperature parts of the power coupler result in additional cryogenic heat loads. Excessive heat load in 2K environment may degrade overall performance of the cavity. In this paper we present studies perfor...

For cost effective machining it is necessary to identify and quantify changes in tool material machining characteristics. Cryoprocessing, a supplementary process to conventional heat treatment, involves deepfreezing of materials at cryogenic temperatures to enhance the mechanical and physical properties. The execution of cryoprocessing on cutting tool materials increases wear resistance, hardne...

In this study, fatigue crack growth rates (FCGR) of 7% nickel steel at room and cryogenic temperatures were evaluated using damage-coupled finite element analysis (FEA). In order to perform the computational fatigue analysis effectively, methods for coupling damage to FEA are introduced and adopted. A hybrid method including the damage-coupled constitutive model and jump-in-cycles procedure was...

PDMS micro-sensors coated onto an electrical wire are used to measure dynamic temperature variation at cryogenic range based on optical whispering-gallery mode (WGM) frequency shift principle. We designed a lab cryogenic cell via filling liquid nitrogen to create a stable low temperature down to 95K. The electrical wire is current carrying to simulate a working electrical/electronic component/d...

Cryogenic detectors operated at temperatures below 1 K offer an order of magnitude higher energy resolution than conventional semiconductor-based energy-dispersive detectors, and orders of magnitude higher efficiency that grating spectrometers. Initially developed for astrophysics applications, these detectors are increasingly used in synchrotron-based research, both for detector characterizati...

We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios of about 100-200 at lowest and highest measures temperature were achieved when the positioner applied its maximum force o...

Applications of cryogenics in space The development, in-orbit commissioning, and operation of cryogenic instrumentation in space raises the level of mission complexity, risk and associated cost. Any application must then be justified on the basis of its specific return. In the case of scientific missions, the cryogenic detectors and related payloads are the only candidates for the accomplishmen...