scholarly journals Charge stripping ofU238ion beam by helium gas stripper

2012 ◽  
Vol 15 (12) ◽  
Author(s):  
H. Imao ◽  
H. Okuno ◽  
H. Kuboki ◽  
S. Yokouchi ◽  
N. Fukunishi ◽  
...  
Keyword(s):  
Helium Gas ◽  
Gas Stripper

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

Activation of deionized water by atmospheric plasma jet in helium gas flow

2021 ◽  
Author(s):  
P. Y. Tan ◽  
O. H. Chin ◽  
R. Anpalagan ◽  
Y. T. Lau ◽  
H. C. Lee
Keyword(s):  
Gas Flow ◽  
Plasma Jet ◽  
Deionized Water ◽  
Atmospheric Plasma ◽  
Helium Gas

DESIGN OF A 300 000-Oe TWO-REGION SOLENOID FOR INTERMITTENT OPERATION

1964 ◽  
Vol 42 (7) ◽  
pp. 1343-1357 ◽  
Author(s):  
Richard Stevenson
Keyword(s):  
Magnetic Field ◽  
Cooling System ◽  
Operating Time ◽  
Maximum Power ◽  
Magnet System ◽  
Total Operating Time ◽  
Helium Gas ◽  
Intermittent Operation ◽  
The Magnetic Field ◽  
Capital Expense

This paper contains a design of an aluminum solenoid magnet system capable of producing a field of 300 000 Oe over a bore of 5.8 cm. The magnetic field is produced by a two-region solenoid operated at 15 °K and cooled by compressed helium gas. Details of the structure are described, and calculations are given for all important parts of the cooling system. The magnet is designed for a total operating time at maximum power of at least 40 minutes in a week. The low capital expense of the system makes it suitable for installation in small laboratories.

scholarly journals Accurate Electron Drift Mobility Measurements in Moderately Dense Helium Gas at Several Temperatures

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 52
Author(s):  
Armando Francesco Borghesani
Keyword(s):  
Weak Localization ◽  
Drift Mobility ◽  
Zero Field ◽  
Scattering Effects ◽  
Helium Gas ◽  
Excellent Description ◽  
Intermediate Density ◽  
Electron Drift Mobility ◽  
Multiple Scattering Effects ◽  
Density Regime

We report new accurate measurements of the drift mobility μ of quasifree electrons in moderately dense helium gas in the temperature range 26K≤T≤300K for densities lower than those at which states of electrons localized in bubbles appear. By heuristically including multiple-scattering effects into classical kinetic formulas, as previously done for neon and argon, an excellent description of the field E, density N, and temperature T dependence of μ is obtained. Moreover, the experimental evidence suggests that the strong decrease of the zero-field density-normalized mobility μ0N with increasing N from the low up to intermediate density regime is mainly due to weak localization of electrons caused by the intrinsic disorder of the system, whereas the further decrease of μ0N for even larger N is due to electron self-trapping in cavities. We suggest that a distinction between weakly localized and electron bubble states can be done by inspecting the behavior of μ0N as a function of N at intermediate densities.

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