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In a previous contribution to this journal [H. P. Stormberg, J. Appl. Phys. 51(4), 1963(1980], Stormberg presented an analytical expression for the convolution of Lorentz and Levy line profiles, which models atomic radiative transitions in high pressure plasmas. Unfortunately, the derivations are flawed with errors and the final expression, while correct, is accompanied by misguiding comments about the meaning of the symbols used therein, in particular the "complex error function." In this paper, we discuss the broadening mechanisms that give rise to Stormberg's model and present a correct derivation of his final result. We will also provide an alternative expression, based on the Faddeeva function, which has decisive computational advantages and emphasizes the real-valuedness of the result. The MATLAB/Octave scripts of our implementation have been made available on the publisher's website for future reference. V C 2013 AIP Publishing LLC. [http://dx

The mercury free lamp model previously discussed in Gnybida et al (2014 J. Phys. D: Appl. Phys. 47 125201) did not account for selfconsistent diffusion and only included two molecular transitions. In this paper we apply, for the first time, a selfconsistent diffusion algorithm that features (1) species/mass conservation up to machine accuracy and (2) an arbitrary mix of integral (total mass) and local (cold spot) constraints on the composition. Another advantage of this model is that the total pressure of the gas is calculated self consistently. Therefore, the usage of a predetermined pressure is no longer required.Additionally, the number of association processes has been increased from 2 to 6. The population as a function of interatomic separation determines the spectrum of the emitted continuum radiation. Previously, this population was calculated using the limit of low densities. In this work an expression is used that removes this limitation. The result of these improvements is that the agreement between the simulated and measured spectra has improved considerably.

Abstract.A set-up that aims to determine the infrared radiation fraction of the energy balance of high intensity discharge (HID) lamps has been designed, constructed and calibrated. It consists of a high-resolution integrating sphere that can cover a wide spectral range. New in this work is that the integrating sphere measurements can be used in the infrared part of the spectrum up to 10 µm and that we have calibrated the absolute intensity in that range. No calibration standards for spectral radiant flux are readily available in the infrared. Therefore, we have used a resistive heated platinum ribbon as absolute intensity reference. As a first testcase, this new set-up was used to determine the energy balance of a Philips CDM-T 70W/830 lamp, which is a type of metal halide HID lamp. IntroductionHigh intensity discharge lamps (HID lamps) are used when compact light sources are needed with high output levels and efficacies. This study deals with the experimental determination of the energy balance of HID lamps, i.e. the distribution of the total output energy of the lamp over different spectral regions is investigated. By determining and studying the energy balance of the lamp, the understanding of the energy flows inside the lamp can be improved. This can aid in the improvement of existing lamps and development of new ones. . From these studies it can be concluded that infrared radiation is an important contribution to the energy balance of HID lamps. Infrared radiation, either in the form of radiation from the plasma or in the form of thermal radiation from the burner wall, can consume 50-75% of the total input power. The ALITE-II project's [6] primary focus was the infrared radiation of HID lamps; several papers regarding the infrared radiation from HID lamps have recently been published [7][8][9]. In these papers the focus was mainly on the continuum radiation generated by the plasma. As far as we know, other authors studying the infrared radiation of HID lamps have based their infrared work on side-on measurements, and/or did not measure the radiation beyond about 2.5 µm