scholarly journals The liquefaction of helium by an adiabatic method

1934 ◽  
Vol 147 (860) ◽  
pp. 189-211 ◽  
Keyword(s):  
Liquid Helium ◽  
High Pressures ◽  
Scientific Work ◽  
Liquid Hydrogen ◽  
Thermal Capacity ◽  
Liquid Oxygen ◽  
Reduced Pressure ◽  
External Work ◽  
Adiabatic Principle ◽  
Continuous Output

The liquefaction of helium by Kammerlingh Onnes has led in the past thirty years to discoveries of the greatest importance to the study of the solid state. In spite of this, very few laboratories are now equipped with the apparatus necessary for the production of liquid helium. It is therefore very desirable that the complicated technique necessary for its production should be simplified to allow of its more extensive use. In this paper we shall describe a more efficient liquefier, based on an adiabatic principle, which we hope will considerably simplify the production of liquid helium for scientific work. At present two principal methods are used for the cooling and liquefying of gases. The first method is based on cooling produced by adiabatic expansion where the expanding gas is cooled by doing external work. This phenomenon was observed by Clèment and Desormes in 1819 when they discovered the cooling of a gas in a container when its pressure was reduced by letting out some of the gas through a tap. It can be shown that on expanding, the gas remaining in the container has done work in communicating kinetic energy to the escaped gas, and therefore has been cooled adiabatically. Olszewski in 1895 applied this method to the liquefaction of hydrogen; he compressed the gas to 190 atmospheres and pre-cooled it with liquid oxygen boiling at reduced pressure (-211°C); on releasing the pressure, he observed a fog of liquid hydrogen drops. From this experiment he was able to determine the critical data for hydrogen. This method has also been used recently by Simon for liquefying helium. Simon took advantage of the fact that at very low temperatures the thermal capacity of the container is so small that it practically absorbs no cold from the liquefied helium. The limitations of this method are that it can only conveniently be applied for obtaining small amounts of liquid helium; it is not suited for a continuous output of helium, and also there is necessarily a loss of cold due to the gas which leaves the container. The method is also complicated by the fact that high pressures are required, and that pre-cooling with liquid hydrogen boiling at reduced pressure is necessary.

A Spray-On Cryogenic Insulating Material for NASA Which Prevents the Formation of Liquid Oxygen on Liquid Hydrogen Vent Lines

1994 ◽  
pp. 1177-1182 ◽  
Author(s):  
M. L. Tupper ◽  
A. L. Pulley ◽  
E. F. Johnson ◽  
N. A. Munshi ◽  
P. E. Fabian ◽  
...  
Keyword(s):  
Liquid Hydrogen ◽  
Liquid Oxygen ◽  
Insulating Material

scholarly journals The vapour pressures of liquid oxygen on the scale of the constant-volume oxygen thermometer filled at different initial pressures

1904 ◽  
Vol 72 (477-486) ◽  
pp. 386-391 ◽  
Keyword(s):  
Liquid Hydrogen ◽  
Constant Volume ◽  
Liquid Oxygen

The vapour pressures of liquid oxygen and liquid hydrogen on the scales of the constant-volume hydrogen and helium thermometers has recently been determined by one of us in conjunction with Dr. A. Jaquerod and Mr. G. Senter, and it has been found that two scales of temperature differ by amounts which increase as the temperature falls.

scholarly journals On the refractivity of para-hydrogen

1933 ◽  
Vol 139 (839) ◽  
pp. 517-520 ◽  
Keyword(s):  
Refractive Index ◽  
Cylindrical Tube ◽  
Liquid Hydrogen ◽  
Liquid Oxygen ◽  
Para Hydrogen ◽  
Warm Up ◽  
The Wire ◽  
Set Up ◽  
Thermal Conductivities

In the paper by K. F. Bonhoeffer and P. Harteck published in 1929, on para-hydrogen, no mention is made of the refractive index of the new modification, and, so far as we can find, no experiments on this subject have hitherto been published. It may, therefore, be presumed that, on the hypothesis which led to the discovery of the para-form, no change of index was expected; and, on any theory, it seemed probable that the change would be very small. It appeared worth while, however, to make use of a Jamin interferometer already set up for other purposes to test this point experimentally and the following paper records the result of the investigation. Para-hydrogen was prepared by adsorbing ordinary hydrogen, purified by previous adsorption in palladium, in charcoal at the temperature of liquid oxygen (—183°C.). After 1 1/2 to 2 hours the gas was allowed to warm up, and should then consist of approximately 50 per cent, ortho- and 50 per cent, para-hydrogen. In order to test whether this wTas actually so Schleiermacher’s method of measuring the thermal conductivities of the two forms, as described in Bonhoeffer and Harteck’s paper, was followed. In their case a Wollaston wire (0.01 mm. diameter) was stretched in a narrow cylindrical tube immersed in liquid hydrogen, and the change in the resistance of the wire, which was electrically heated to 200° absolute, was observed when para- was substituted for ordinary hydrogen at the same pressure (40 mm.). In these circumstances the resistance varied between 111.85 ohms for ordinary hydrogen to 106.25 for hydrogen containing 99.7 per cent, para-hydrogen.

Excess electrons in liquid hydrogen, liquid neon, and liquid helium

1982 ◽  
Vol 12 ◽  
pp. 89-96 ◽  
Author(s):  
Y. Sakai ◽  
H. Böttcher ◽  
W.F. Schmidt
Keyword(s):  
Liquid Helium ◽  
Liquid Hydrogen ◽  
Excess Electrons ◽  
Liquid Neon

FIRST SOUND IN LIQUID HELIUM AT HIGH PRESSURES

1953 ◽  
Vol 31 (7) ◽  
pp. 1156-1164 ◽  
Author(s):  
K. R. Atkins ◽  
R. A. Stasior
Keyword(s):  
Specific Heat ◽  
Liquid Helium ◽  
Carrier Frequency ◽  
High Pressures ◽  
Constant Pressure ◽  
Constant Density ◽  
Pulse Technique ◽  
Temperature Range ◽  
Specific Heats ◽  
First Sound

The velocity of ordinary sound in liquid helium has been measured in the temperature range from 1.2 °K. to 4.2 °K. at pressures up to 69 atm. A pulse technique was used with a carrier frequency of 12 Mc.p.s. Curves are given for the variation of velocity with temperature at constant pressure and also at constant density. There is no detectable discontinuity along the λ-curve. The results are used to discuss the ratio of the specific heats, the coefficient of expansion below 0.6 °K., and the specific heat above 3 °K.

Evaporation rates of liquid hydrogen and liquid oxygen spilled onto the ground

1994 ◽  
Vol 7 (5) ◽  
pp. 425-431 ◽  
Author(s):  
Keiji Takeno ◽  
Toshimitsu Ichinose ◽  
Yukio Hyodo ◽  
Hiroyuki Nakamura
Keyword(s):  
Liquid Hydrogen ◽  
Liquid Oxygen
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