Nitrogen gas propagation in a liquid helium cooled vacuum tube following a sudden vacuum loss

26th International Cryogenic Engineering Conference & International Cryogenic Materials Conference 2016

材料科学;物理学

Dhuley, R.C.^1,2 ; Van Sciver, S.W.^1,2

Mechanical Engineering Department, FAMU-FSU College of Engineering, Tallahassee

FL

32310, United States^1

National High Magnetic Field Laboratory, Tallahassee

FL

32310, United States^2

关键词: Atmospheric air;    Front propagation;    High vacuum;    Liquid helium;    Nitrogen gas;    Pressure probes;    Tube length;    Vacuum loss;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/171/1/012084/pdf
DOI  :  10.1088/1757-899X/171/1/012084

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

We present experimental measurements and analysis of propagation of the nitrogen gas that was vented to a high vacuum tube immersed in liquid helium (LHe). The scenario resembles accidental venting of atmospheric air to a SRF beam-line and was investigated to understand how the in-flowing air would propagate in such geometry. The gas front propagation speed in the tube was measured using pressure probes and thermometers installed at regular intervals over the tube length. The experimental data show the front speed to decrease along the vacuum tube. The empirical and analytical models developed to characterize the front deceleration are summarized.