2 edition of **Electron density determination in a thermionically assisted Cs-Ar discharge** found in the catalog.

Electron density determination in a thermionically assisted Cs-Ar discharge

Kevin P Shields

- 383 Want to read
- 17 Currently reading

Published
**1990**
.

Written in English

- Electron distribution,
- Physics

**Edition Notes**

Statement | by Kevin P. Shields |

The Physical Object | |
---|---|

Pagination | 66 leaves : |

Number of Pages | 66 |

ID Numbers | |

Open Library | OL14695500M |

discharge in air, at a current of 10 mA, the electron density was found to be cm−3 in the centre, decreasing to half of this value at a radial distance of mm. Gaussian temperature proﬁles with σ = 1. 1 mm and maximum values of – K in the centre were also. Spatial resolution of the electron density in the high-pressure glow discharge with characteristic dimensions on the order of µ m required the use of a CO 2 laser at a wavelength of µ m. For this wavelength and electron densities greater than 10 11 cm -3 the index of refraction of the atmospheric air plasma is mainly determined by.

for low electron temperature and density measurement in helium RF discharge [4]. 42 T ransition between α and γ mode of RF discharge in argon was investigated in [5]. Time- Purpose. This study aimed to quantitate the accuracy of the determination of electron density (ED), effective atomic number (Z eff), and iodine concentration, directed for more accurate radiation therapy planning, with a new dual‐layer dual‐energy computed tomography (DL‐DECT) dependence of the accuracy of these values on the scan and reconstruction parameters, as well as on.

For these reasons, modelling is a necessity in order to obtain a static electron density distribution, which can reliably represent the quantum mechanical function, obtained with ab initio calculations. Some methods, especially those based on the maximum likelihood and Bayesian statistics, reconstruct the thermally averaged electron charge density, a three dimensional function that . The electron-density distribution is the three-dimensional realspace arrangement of the electrons in the material. Because electrons are quantum mechanically delocalized, each electron occupies a 'fuzzy' region of space (electron cloud).The total electron density--the summation of the electron distribution for every electron in every atom--is thus inherently spread spatially; e.g a map of.

You might also like

An illustration of an open book. Books. An illustration of two cells of a film strip. Video An illustration of an audio speaker. Electron Density in an Electron Beam Stabilized High Pressure Discharge Item Preview The basic differential equations for the electron beam stabilized discharge are formulated and a discussion of the relevant.

Measurements were made of the absorption of microwave power in a discharge plasma generated using tapwater electrodes in atmospheric-pressure air in order to determine the electron density. The high-voltage discharge burned in a bulk (diffuse) form with a lower current density than an arc discharge.

This type of discharge with nonmetallic liquid electrodes is extremely promising for Cited by: The electron density distribution, n/n 0 vs r, was not determined with the desired accuracy. Disturbance of the discharge made the probe current rise too rapidly as the probe approached the axis.

After due allowance for errors, n/n 0 in the neon discharge seemed to vary roughly as the Bessel function J 0 ( r/R), where R=radiusCited by: 3. A method is developed for measuring the electron density in argon during atmospheric pressure dielectric barrier discharge.

The oscillating electromagnetic signal is detected by an antenna at a distance from the plasma source. The electron density is then calculated from the ion oscillation frequency. The results show that the electron density in the plasma after the turnoff of the discharge Cited by: The reduced electric field maximum in the streamer head in mid-gap was found to be around Td and the electron number density ()*10e14 cm-3, taking into account an initial gas.

A novel spectroscopic method is proposed for the measurement of electron density and temperature in atmospheric pressure dielectric barrier discharges using nitrogen gas.

Simplified collisional-radiative models for the electronic and the vibrational states yield two separate continuity equations as a function of the electron density and the temperature with the coefficients expressed.

The electron density in a subatmospheric dielectric barrier discharge by using argon spectral line shape is measured for the first time. With the gas pressure increasing in the range of 1 × 10 4 Pa – 6 × 10 4 Pa, the line profiles of argon nm are asymmetrical deconvolution procedure is applied to separate the Gaussian and Lorentzian profile from the measured spectral line.

The discharge power supply (Bertan Serie ) was maintained at an. output of V and a current of A ( W), which was measured using a digital Fluke multimeter model Langmuir probes are commonly used as a diagnostic tool for the determination of plasma parameters, such as electron temperature and ion density.

Spectra of neutral helium in the visible wavelength range are measured for a discharge in the Large Helical Device (LHD). The electron temperature (T e) and density (n e) are derived from the intensity distribution of helium emission that purpose, a collisional-radiative model developed by Sawada et al.

[Plasma and Fusion Res. ;] which takes the reabsorption effect into. Read 4 answers by scientists with 1 recommendation from their colleagues to the question asked by Ranjith Kumar on [Determination of electron density in Ar-air mixed coolant gas ICP].

[Article in Chinese] Li Y(1), Zeng X, Wang S, Lei L, Ni Y. Author information: (1)Department of Chemistry, Trace Elements Institute of Tongji University, Shanghai.

The lateral distribution of electron number density at 0, 2, 5, 10 mm above the load coil in Ar-air mixed. Electron density and temperature determination in an ICP assume quasi-neutrality {n^n^). Writing Eqn (1) for the limit (i->co), i.e. for the ionization potential (,=/i), we define r'sx=g'v2{2^mkT,}3!l (3) The value of^^ may be determined experimentally by measuring absolute line intensities of highly excited argon states for which we.

We propose a new type of capacitive plasma source with a mesh grid to solve the problems of previous low pressure discharges, the inability to control the electron density and temperature independently, i.e.

just one value of electron temperature is possible for a given electron density. While varying the grid bias and the discharge current, various electron temperatures are possible for a. The standard deviation in the measured relative electron density data increases on average by a factor of by reducing the slice thickness from to mm.

The accuracy in the measured relative electron density data for mm slice thickness is better than % except for aluminium and LN The electron density is measured by means of a microwave toroidal resonator.

In the form with higher gradient (so-called “H” form), a lower electron density than in the form with lower gradient (so-called “T” form) is found. The electron density in the two types of oxygen discharge plasma, which differ in cathode fall, is measured too.

Determination of n e and T e in capacitively coupled RF discharge in neon 3 65 e.g. in [18]. Trace rare gases optical emission spectroscopy (TRG-OES), based on 66 the addition of a small admixture of rare gas into the studied plasma and evaluation 67 of plasma parameters from the best ﬁt between the measured and with CR model 68 calculated relative emission intensities, was reviewed in [19].

CALCULATION OF ELECTRON DENSITY FROM THE INTENSITY RATIO OF SPECTRAL LINES OF A GIVEN ION S. SUCKEWER Institute of Nuclear Research, 9wierk a, Poland Received 14 July It is shown that from the relative intensities of two chosen lines of a given ion it is possible to determine the electron density of nonthermal plasmas.

Oscillation‐free arcs were operated at or A in a tube with a 34 mm i.d. and a filling pressure of 7 Torr for neon, and 1–2 Torr for Ar, Kr, and Xe. Probes, including one moved radially, were used to determine positive column characteristics, particularly the axial electron density n0.

In each computation, corrections were made for the radial variation of gas temperature. A method for determining the electron temperature and electron density in a plasma is proposed that is based on minimization of the difference between the experimental relative intensities of the spectral argon (Ar) lines and those same intensities calculated with the aid of the collisional-radiative model.

The model describes the kinetics of the ground state and 40 excited states of the Ar. Using Langmuir probes in an argon triode discharge (filament bias current, –2 A; substrate bias voltage, 0–2 kV) between and 2 Pa, Swarnalatha et al. found that the electron density n e increases with increasing filament bias current with a maximum around Pa.

Electron density profiles. Results are presented for electron density profiles (EDPs) from several binary choices in methodology: the URS method (DF or RI), the atom selection method (TC or P), the filter method (ID or L4), and the surface referencing method (OA or UC).

Comparisons in this subsection are for the system with DMPC lipids. Fig. 2 (see also Table 1) shows the factor increase in T e during titanium evaporation for 1, 2 and 4 Pa argon gas pressures. There is close agreement for the calculated factor increase in T e between the two different emission lines chosen for Ar +.This factor appears to decrease with increasing gas pressure.

At 1 Pa the average percentage increase in T e is % but this reduces to % at.The electron temperatureTe and the electron density were measured as functions of the radial distance in a 10 Mc/s electrodeless ring discharge in hydrogen in the pressure range – Torr. It was found thatTe remains nearly constant along the radius of the cylindrical vessel.

The measured values ofTe have been compared with those observed by other workers and an estimate of the effective.