The Maxwellian nature of free-electrons' gas spectrum of noble gases at low pressure

Vacuum ◽  
2014 ◽  
Vol 110 ◽  
pp. 19-23 ◽  
Author(s):  
Mališa Alimpijević ◽  
Koviljka Stanković ◽  
Milan Ignjatovic ◽  
Jovan Cvetić
Keyword(s):  
Noble Gases ◽  
Low Pressure ◽  
Free Electrons

scholarly journals Electronic stopping of protons in xenon plasmas due to free and bound electrons

2013 ◽  
Vol 31 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Manuel D. Barriga-Carrasco ◽  
David Casas
Keyword(s):  
Oscillator Strength ◽  
Close Agreement ◽  
Noble Gases ◽  
Previous Literature ◽  
Free Electrons ◽  
Hartree Fock ◽  
Plasma Target ◽  
Strength Functions ◽  
Bound Electrons

AbstractIn this work, proton stopping due to free and bound electrons in a plasma target is analyzed. The stopping of free electrons is calculated using the dielectric formalism, well described in previous literature. In the case of bound electrons, Hartree-Fock methods and oscillator strength functions are used. Differences between both stopping, due to free and bound electrons, are shown in noble gases. Then, enhanced plasma stopping can be easily estimated from target ionization. Finally, we compare our calculations with an experiment in xenon plasmas finding a close agreement.

scholarly journals Opacity and conductivity measurements in noble gases at conditions of planetary and stellar interiors

2015 ◽  
Vol 112 (26) ◽  
pp. 7925-7930 ◽  
Author(s):  
R. Stewart McWilliams ◽  
D. Allen Dalton ◽  
Zuzana Konôpková ◽  
Mohammad F. Mahmood ◽  
Alexander F. Goncharov
Keyword(s):  
High Pressures ◽  
Noble Gases ◽  
Structural Evolution ◽  
Wide Band ◽  
Amorphous Semiconductor ◽  
Stellar Atmospheres ◽  
Metallic Hydrogen ◽  
Free Electrons ◽  
White Dwarf Stars ◽  
Different Color

The noble gases are elements of broad importance across science and technology and are primary constituents of planetary and stellar atmospheres, where they segregate into droplets or layers that affect the thermal, chemical, and structural evolution of their host body. We have measured the optical properties of noble gases at relevant high pressures and temperatures in the laser-heated diamond anvil cell, observing insulator-to-conductor transformations in dense helium, neon, argon, and xenon at 4,000–15,000 K and pressures of 15–52 GPa. The thermal activation and frequency dependence of conduction reveal an optical character dominated by electrons of low mobility, as in an amorphous semiconductor or poor metal, rather than free electrons as is often assumed for such wide band gap insulators at high temperatures. White dwarf stars having helium outer atmospheres cool slower and may have different color than if atmospheric opacity were controlled by free electrons. Helium rain in Jupiter and Saturn becomes conducting at conditions well correlated with its increased solubility in metallic hydrogen, whereas a deep layer of insulating neon may inhibit core erosion in Saturn.

Low-pressure Noble Gas Broadening of the Cs Resonance Lines

1984 ◽  
Vol 39 (5) ◽  
pp. 447-454 ◽  
Author(s):  
F. Siegling ◽  
K. Niemax
Keyword(s):  
Resonance Line ◽  
Noble Gases ◽  
Noble Gas ◽  
Low Pressure ◽  
Theoretical Line ◽  
Low Pressures

The wings of the Cs resonance line (62S1/2 - 62P1/2, 3/2) broadened by noble gases (He, Ne, Ar and Kr) at low pressures (p ≦ 700 Torr) have been measured in absorption in the range 4 up to a few hundred wavenumbers from the line centres. The far wings are compared with quasistatic wings based on the semiempirical potentials by Baylis and by Pascale and Vandeplanque. In some cases the agreement between the experimental and theoretical line wings is found to be reasonable

Violating the free-electrons gas spectrum of noble gases by adding the electropositive and electronegative gases

2015 ◽  
Author(s):  
Luka Perazic ◽  
Koviljka Sankovc ◽  
Cedomir Belic ◽  
Malia Alimpijevic ◽  
Irfan Fetahovic
Keyword(s):  
Noble Gases ◽  
Free Electrons

scholarly journals The Effect of Axial Magnetic Field on The Breakdown Voltage of Air at Low Pressure

2020 ◽  
pp. 3228-3234
Author(s):  
Ahmed Owaid ◽  
Ahmed Y. Owaid
Keyword(s):  
Magnetic Field ◽  
Breakdown Voltage ◽  
Axial Magnetic Field ◽  
Low Pressure ◽  
Discharge Voltage ◽  
Magnetic Flux Density ◽  
Free Electrons ◽  
Maximum Decrease ◽  
Paschen Curve ◽  
The Right

To add more details about the effect of the axial magnetic field on the plasma profile, the breakdown voltage of air was investigated at low pressure (9-15 Pa) in the presence of axial magnetic field (0.01-0.04T). The air was ignited by a DC voltage between two plain electrodes of aluminum separated by a distance (8.5cm). The measurements showed that the discharge voltage decreases to a minimum value, then returns to increase over the minimum with increasing the magnetic field strength, at all pressures in the range. It was also observed that a maximum decrease in the discharge voltage is obtained near the minimum of  Paschen curve from the right side. The decrease in the discharge voltage was caused mainly by the effect of magnetic flux density on the diffusion of charged particles to the walls, especially on that of free electrons which were borne during the breakdown process.

Effects of Electrical Discharges in Low Pressure Gases on the Morphology of Polyethylene Crystals

1974 ◽  
Vol 32 ◽  
pp. 544-545
Author(s):  
L.H. Bolz ◽  
D.H. Reneker
Keyword(s):  
Power Distribution ◽  
Electrical Discharge ◽  
Dielectric Breakdown ◽  
Ionic Species ◽  
Low Pressure ◽  
Polymer Surfaces ◽  
Electrical Discharges ◽  
Adhesive Bonds ◽  
Power Distribution Lines ◽  
Modification Of The Surface

The attack, on the surface of a polymer, by the atomic, molecular and ionic species that are created in a low pressure electrical discharge in a gas is interesting because: 1) significant interior morphological features may be revealed, 2) dielectric breakdown of polymeric insulation on high voltage power distribution lines involves the attack on the polymer of such species created in a corona discharge, 3) adhesive bonds formed between polymer surfaces subjected to such SDecies are much stronger than bonds between untreated surfaces, 4) the chemical modification of the surface creates a reactive surface to which a thin layer of another polymer may be bonded by glow discharge polymerization.

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