Paschen

Bafmer series Frequencies of certain lines in the spectrum of hydrogen are simply related to each other, and can be expressed by a general formula. One group of lines is termed the Balmer series. Other series were later discovered in the spectrum of hydrogen by Lyman, Paschen, Brackett and Pfund. 

Figure 1.1 Energy levels (vertical lines) and observed transitions (horizontal lines) of the hydrogen atom, including the Lyman, Balmer, Paschen, Brackett and Pfund series...

Comparison with the empirical Equation (1.4) shows that = /re /S/z eg and that n" = 2 for the Balmer series. Similarly n" = 1, 3, 4, and 5 for the Lyman, Paschen, Brackett and Pfimd series, although it is important to realize that there is an infinite number of series. Many series with high n" have been observed, by techniques of radioastronomy, in the interstellar medium, where there is a large amount of atomic hydrogen. For example, the (n = 167) — ( " = 166) transition has been observed with V = 1.425 GFIz (1 = 21.04 cm). 

When fhe members of fhe Balmer and Paschen series (see Figure f. f) are observed af high resolution fhey show closely spaced fine strucfure and if was an imporfanf fesf of quanfum mechanical mefhods fo explain fhis. 

Paschen s Rule and Breakdown Voltage. As pressure decreases to vacuum conditions, the breakdown voltage (BDV) first decreases, then increases, resulting in a minimum as shown in Figure 1. Table 3 gives BDV data for SF and other dielectrics. For optimum utiUty of a dielectric, a... 

G. Luxa and co-workers. Item D. Paschen CurveforSF, 1975 CIGRE International Conference on Earge High Tension Electrical Systems. 

Lyman Series) (Balmer Series) (Paschen Series)... 

All of the lines in the Balmer series (Table 6.1) come from transitions to the level n = 2 from higher levels (n = 3, 4, 5,. . . ). Similarly, lines in the Lyman series arise when electrons fall to the n = 1 level from higher levels (n = 2, 3, 4,. . . ). For the Paschen series, which lies in the infrared, the lower level is always n = 3. 

In the Paschen series, ni = 3. Calculate the longest wavelength possible for a transition in this series. 

Pascal An SI unit of pressure the pressure exerted by the force of 1 newton on an area of 1 square meter, 104,635 Paschen series, 138 Pasteur, Louis, 601 Pauli exclusion principle, 141-143 Pauling, Linus, 185 Pentyl propionate, 596t Peptide linkage The—C—N—group... 

C07-0126. The series of emission lines that results from excited hydrogen atoms undergoing transitions to the n — 3 level Is called the Paschen series. Calculate the energies of the first five lines In this series of transitions, and draw an energy level diagram that shows them to scale. 

Titles K, Bund A, Plieth W, Bentien A, Paschen S, Pldttner M, Grafe H, Fischer WJ (2003) Electrochemical deposition of Bi2Te3 for thermoelectric microdevices. J Solid State Electrochem 7 714-723... 

The discovery of two other series of emission lines of hydrogen came later. They are named for their discoverers the Lyman series in the ultraviolet range and Paschen series in the infrared region. Although formulas were devised to calculate the spectral lines, the physics behind the math was not understood until Niels Bohr proposed his quantized atom. Suddenly, the emission spectrum of hydrogen made sense. Each line represented the energy released when an excited electron went from a higher quantum state to a lower one. 

A vertical cross section of the reaction chamber is shown in Figure 6. The inside diameter of the chamber amounts to 200 mm. The diameters of the grounded and powered electrodes are 180 and 148 mm, respectively, with a fixed interelectrode distance of 36.5 mm. The interelectrode distance has also been changed to 27 mm, and recently a modified powered electrode assembly has been retrofitted, with which it is possible to vary the interelectrode distance from 10 to 40 mm from the outside, i.e., without breaking the vacuum [162]. With process pressures in the range of 0.1-0.6 mbar the product of pressure and interelectrode distance, pL, may range from about 0.1 to 6 mbar cm. In practice, pL values are between 0.4 and 1.5 mbar cm, i.e., around the Paschen law minimum (see Section 1.3.2.4). 

In order to sustain a discharge between two parallel plate electrodes, the product of pressure p and interelectrode distance L has to satisfy the Paschen law for the... 

FIG. 12. Measured Paschen law for silane, hydrogen, nitrogen, and argon. (Redrawn from K. M. H. Maessen, Ph.D. Thesis. Universileit Utrecht. Utrecht, the Netherlands. 1988. with permission.)... 

The study of the hydrogen atom also played an important role in the development of quantum theory. The Lyman, Balmer, and Paschen series of spectral lines observed in incandescent atomic hydrogen were found to obey the empirical equation... 

The potential of the electrocapillary maximum can be found from the electrocapillary curve while the Paschen method is an alternative. In this... 

Viennois R, Ravot D, Terki F, Hernandez C, Charar S, Haen P, Paschen S, Steglich F (2004) J Magn Magn Mater 272-276 El 13... 

Eventually, other series of lines were found in other regions of the electromagnetic spectrum. The Lyman series was observed in the ultraviolet region, whereas the Paschen, Brackett, and Pfund series were observed in the infrared region of the spectrum. All of these lines were observed as they were emitted from excited atoms, so together they constitute the emission spectrum or line spectrum of hydrogen atoms. 

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