Vorticity enhancement in thermal counterflow of superfluid helium

2018 ◽  
Vol 97 (6) ◽  
Author(s):  
P. Hrubcová ◽  
P. Švančara ◽  
M. La Mantia
Keyword(s):  
Superfluid Helium ◽  
Thermal Counterflow

Thermal counterflow experiments on superfluid helium at temperatures close toTλ

1985 ◽  
Vol 31 (9) ◽  
pp. 5722-5727 ◽  
Author(s):  
A. G. F. Dorscheidt ◽  
H. van Kempen ◽  
P. Wyder ◽  
T. H. K. Frederking
Keyword(s):  
Superfluid Helium ◽  
Thermal Counterflow

scholarly journals Three-Dimensionality of Thermal Counterflow in Superfluid Helium Based on PTV Method

2019 ◽  
Vol 2019 (0) ◽  
pp. OS8-08
Author(s):  
Takumi MARUYAMA ◽  
Shinichiro WAKI ◽  
Tatsuya TSUNEYOSHI ◽  
Yoshiyuki TSUJI
Keyword(s):  
Superfluid Helium ◽  
Thermal Counterflow

scholarly journals Energy spectrum of thermal counterflow turbulence in superfluid helium-4

2017 ◽  
Vol 96 (9) ◽  
Author(s):  
J. Gao ◽  
E. Varga ◽  
W. Guo ◽  
W. F. Vinen
Keyword(s):  
Energy Spectrum ◽  
Superfluid Helium ◽  
Thermal Counterflow ◽  
Helium 4

High-Resolution Cryo-Electron Microscopy of Biological Macromolecules

1990 ◽  
Vol 48 (1) ◽  
pp. 126-127
Author(s):  
Yoshinori Fujiyoshi
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Diffraction Pattern ◽  
Superfluid Helium ◽  
Copper Phthalocyanine ◽  
Optical Diffraction ◽  
Irradiation Damage ◽  
Biological Macromolecules ◽  
Cross Sectional ◽  
Instrumental Resolution

The resolution of direct images of biological macromolecules is normally restricted to far less than 0.3 nm. This is not due instrumental resolution, but irradiation damage. The damage to biological macromolecules may expect to be reduced when they are cooled to a very low temperature. We started to develop a new cryo-stage for a high resolution electron microscopy in 1983, and successfully constructed a superfluid helium stage for a 400 kV microscope by 1986, whereby chlorinated copper-phthalocyanine could be photographed to a resolution of 0.26 nm at a stage temperature of 1.5 K. We are continuing to develop the cryo-microscope and have developed a cryo-microscope equipped with a superfluid helium stage and new cryo-transfer device.The New cryo-microscope achieves not only improved resolution but also increased operational ease. The construction of the new super-fluid helium stage is shown in Fig. 1, where the cross sectional structure is shown parallel to an electron beam path. The capacities of LN2 tank, LHe tank and the pot are 1400 ml, 1200 ml and 3 ml, respectively. Their surfaces are placed with gold to minimize thermal radiation. Consumption rates of liquid nitrogen and liquid helium are 170 ml/hour and 140 ml/hour, respectively. The working time of this stage is more than 7 hours starting from full LN2 and LHe tanks. Instrumental resolution of our cryo-stage cooled to 4.2 K was confirmed to be 0.20 nm by an optical diffraction pattern from the image of a chlorinated copper-phthalocyanine crystal. The image and the optical diffraction pattern are shown in Fig. 2 a, b, respectively.

VISCOSITY OF NORMAL AND SUPERFLUID HELIUM THREE

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-35-C6-36 ◽  
Author(s):  
J. M. Parpia ◽  
D. J. Sandiford ◽  
J. E. Berthold ◽  
J. D. Reppy
Keyword(s):  
Superfluid Helium ◽  
Helium Three
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