A self-consistent LTE model of a microwave-driven, high-pressure sulfur lamp

Abstract

A one-dimensional LTE model of a microwave-driven sulfur lamp is presented to aid our understanding of the discharge. The energy balance of the lamp is determined by Ohmic input on one hand and transport due to conductive heat transfer and molecular radiation on the other. We discuss the origin of operational trends in the spectrum, present the model and discuss how the material properties of the plasma are determined. Not only are temperature profiles and electric field strengths simulated but also the spectrum of the lamp from 300 to 900 nm under various conditions of input power and lamp filling pressure. We show that simulated spectra demonstrate observed trends and that radiated power increases linearly with input power as is also found from experiment.

Atmospheric pressure plasmas: A review

“…These discharges are fed with microwave [97]. In 1994 Fusion Lighting Systems produced the Solar 1000, a microwavedriven high pressure lamp with sulfur as the radiating medium [98]. This sulfur lamp (see Fig.…”

On the atomic line profiles in high pressure plasmas

“…For example in a high pressure mercury discharge containing sodium iodide, the ratio can become large at lower temperatures were the sodium is bound in molecules. In methods like raytracing, 22 a correct calculation of the line profile at lower temperatures is also required to account for the absorption accurately.…”

Time-Dependent Behavior of a Lead Titanate Zirconate Wafer under Constant Electric Fields at High Temperatures

“…In figure 11 the LTE densities of the sulphur particles is shown as a function of temperature for a partial sulphur pressure of 5 bar [3,5]. Figure 12 shows the temperature dependence of the electrical conductivity σ and the thermal conductivity λ c as a function of temperature for the sulphurargon mixture [3].…”

“…Figure 12 shows the temperature dependence of the electrical conductivity σ and the thermal conductivity λ c as a function of temperature for the sulphurargon mixture [3]. The temperature equation (41) is solved iteratively.…”

“…A self-consistent model for this spherical lamp has been described before by Johnston et al [3], where the details of the radiative transfer description were deferred to this paper and the theory behind the local S 2 molecular radiation generation characteristics is described in [4]. The S 2 molecular radiation theory in [4] is a semi-classical (SC) description that is far less computationally intensive than a full quantum-mechanical (QM) ro-vibrational model, and was for this reason used by Johnston [3]. Since then, a comparison between transport of SC and QM radiation has been made, using a non-self-consistent sulphur model with a fixed temperature profile, showing differences between the emitted spectra [5].…”