We analyze single-electron tunneling from the bound state above the surface of liquid helium. For strong enough magnetic fields parallel to the surface, the tunneling must be accompanied by ripplon scattering. The effective width of the tunneling barrier strongly and nonmonotonically depends on the momentum transferred to ripplons. The escape rate is affected by Landau quantization of the state...

Since 1994, 6,198 yeasts and 391 molds belonging to 25 and 37 species, respectively, were stored in Microbank cryogenic vials at >/=-130 degrees C in liquid nitrogen and at -70 degrees C in a freezer. All of the isolates, with the exception of 45 yeasts and 15 dermatophytes, were recovered from both storage temperatures. Good reproducibility was demonstrated for amphotericin B, fluconazole, and...

We have fabricated a cryogenic atomic force microscope that is designed for structural investigation of freeze-fractured biological specimens. The apparatus is operated in liquid nitrogen gas at atmospheric pressure. Freeze-fracturing, freeze-etching and subsequent imaging are carried out in the same chamber, so that the surface topography of a fractured plane is easily visualized without ice c...

Fluorescence measurements are easily made with the aid of a cryogenic fiber optic probe. Emission wavelength time matrixes, excitation emission matrixes, and time-resolved excitation emission matrixes are rapidly collected with a pulsed tunable dye laser, a spectrograph, and an intensified charged-coupled device. Compound identification is based on spectral and lifetime information. The potenti...

The objective of the present chapter is to provide the basic concepts and tools required to understand the inception and development of cavitation in liquid flows. The influence of various parameters as the boundary layer and nuclei content is discussed. A special attention is given to thermal effects which may significantly influence the development of cavitation in thermosensitive fluids as c...

Thermal converters at cryogenic temperature have been recently developed in some metrological laboratories. By means of these devices high sensitivity measurements at the level of 1 mV can be performed. In this paper we report on the evaluation of high critical temperature (HTc) device characteristics. Experimental results show that this device, which operates at liquid nitrogen temperature, ha...

An excellent molecule-based cryogenic magnetic refrigerant, gadolinium acetate tetrahydrate, is here used to decorate selected portions of silicon substrate. By quantitative magnetic force microscopy for a variable applied magnetic field near liquid-helium temperature, the molecules are demonstrated to hold their magnetic properties intact, and therefore their cooling functionality, after their...

The cryogenic system for the Spallation Neutron Source (SNS) is designed by Jefferson Laboratory (JLab) personnel and is based on the existing JLab facility. Our task is to use the JLab control system design [2] as much as practical while remaining consistent with SNS control system standards. Some aspects of the systems are very similar, including equipment to be controlled, the need for PID l...

In this work, a novel technique is presented for the graphene fabrication based on the pulsed laser ablation of graphite target inside the cryogenic liquid using the pulsed nanosecond Q-switched Nd:Y3Al5O12 (Nd:YAG) laser at 1064 nm. Single-stage fabrication process is taken into account as a remarkable advantage without need to high vacuum devices and additional chemical components. The synthe...

We present two cryogenic Application Specific Integrated circuits (ASIC's) realized with a GaAs MESFET process. A single-channel differential or double-channel singleended voltage sensitive preamplifier for 4.2 K operation, to be used with bolometric detectors, was realized and tested. A very simple structure working as a unity gain buffer or as a transconductance amplifier, or even as a shapin...