C. J. B. Pagan

Revised analysis of triply ionized argon (Ar IV)

The spectrum of three times ionized argon (Ar IV), has been observed in the 280-5000 A wavelength range. In the previously reported energy level system for the 3s3p4, 3s23p23d and 3s23p24s configurations, three levels were rejected, J-values of two levels were altered and LS-designations of eight levels were revised. Eight new levels have been added to the even parity system, completing 36 energy level values for the 44 possible levels of these even configurations. We also confirm 20 of the 21 previously reported levels for the 26 possible of the 3s23p3 and 3s23p24p configurations. The configurations are interpreted by fitting the theoretical energy expressions to the observed energy levels using a least-square-fitting technique. 214 lines have been identified as transitions between the studied levels. For 112 of them the classification is new.

REVISED AND EXTENDED ANALYSIS OF FIVE TIMES IONIZED XENON, Xe VI

A capillary discharge tube was used to record the Xe spectrum in the 400-5500 A region. A set of 243 lines of the Xe VI spectrum was observed, and 146 of them were classified for the first time. For all known lines, we calculated the weighted oscillator strengths (gf) and weighted transition probabilities (gA) using the configuration interaction in a relativistic Hartree-Fock approach. The energy matrix was calculated using energy parameters adjusted to fit the experimental energy levels. Core polarization effects were taken into account in our calculations. Experimental energy values and calculated lifetimes are also presented for a set of 88 levels. From these levels, 32 were classified for the first time and 33 had their values revised. Our analysis of the 5s5p5d and 5s5p6s configurations was extended in order to clarify discrepancies among previous works.

Revised and Extended Analysis of Five Times Ionized Argon (Ar VI)

The spectrum of five times ionized argon, (Ar VI), has been observed in the 280-2100 A wavelength range. Eighty-seven lines have been identified as transitions between levels of the 3s23p, 3s3p2, 3s23d, 3p3, 3s3p3d, 3s24s, 3s24d and 3s3p4s configurations. For 33 of the lines the classification is new. Forty-one energy level values belonging to these configurations were analyzed and we propose 9 new energy level values for levels corresponding to odd parity configurations. The configurations are interpreted by fitting the theoretical energy expressions to the observed energy levels using leastsquares techniques. The parameter values are compared with results from Hartree-Fock calculations.

Resonant high-voltage source working at resonance for pulsed laser

A high-voltage power supply suitable to feed a pulsed laser is developed. The power circuit is a series resonant converter parallel loaded, working at the resonant frequency. The voltage source inverter that feeds the resonant circuit is soft-commutated. The switching frequency is limited to a few kHz by the response of the high-voltage rectifiers. Experimental results on a 1 kV/250 W prototype are presented in order to verify the converter behavior. Design procedure, simulation and results are presented.

Wavelengths, Energy Levels, Lifetimes, and Weighted Oscillator Strengths for the S VIII Spectrum

The weighted oscillator strengths (gf) and lifetimes for S VIII presented in this work were obtained by a multiconfigurational Hartree-Fock relativistic approach. In this calculation, the electrostatic energy parameters were optimized by a least-squares procedure in order to improve the adjustment to experimental energy levels. The values for gf and lifetimes were then calculated on the basis of these adjusted parameters. New classifications are proposed for energy levels belonging to the 4s and 4d configurations and lines related to them.

The impacts of technical standards for incandescent lamp manufacture in Brazil

In 1996, a new standard for incandescent lamps was put into practice in Brazil, regulating the manufacture of lamp bulbs to be used by customers connected to the low-tension grid. In spite of having five different tension levels throughout the country, the new standard does not include specifications for incandescent lamps designed to operate at 127 V. Regions served by 127 V, which currently include about 20 million households (about half of the present population), now have to use a lamp designed to operate at the 120 V level according to the new standard. We demonstrate that this leads to significant economic and energy losses in households, the electrical sector and the society as a whole. We propose to return to the previous standard which included specifications for incandescent lamps operated at 127 V.

New spectroscopic data for atomic tungsten XIV

The thirteen times ionized tungsten is isoelectronic with PmI. Wavelengths and transition probabilities for the 5s-5p and 5p-5d transitions of WXIV, identifying the ground state as 4f13 5s2 2F7/2 were calculated. Both, a relativistic Hartree Fock approach, including core-polarization effects, and a purely relativistic multiconfiguration Dirac-Fock method were used for the calculations. Particularly, 5s-5p transitions were compared with experimental results obtained with VUV electron beam ion trap (EBIT) spectroscopy.