Research on Plasma Light Sources

9988282 lawler建议继续研究放电等离子体作为光源。这项研究是与工业界密切合作进行的。第一个任务是继续进行钡（Ba）辉光放电等离子体作为光源的实验和理论研究。在有惰性气体缓冲的辉光放电中，钡作为一种辐射原子具有至关重要的优势。在可达到的温度下，钡具有所需的1 ~ 20 mTorr的蒸汽压，具有低激发构型，在能量小于电离势的一半时具有共振能级，并且在效能曲线的峰值处具有优势共振线。在照明应用中，钡蒸气的主要缺点是它的反应性很强。这些对钡放电的研究可能会导致一种全新的照明技术，类似于20世纪60年代引入的低压钠（Na）技术。目前，低压钠灯的发光效率是所有商业照明产品中最高的，但不幸的是，这些灯产生的光几乎是单色光。提出的Ba灯技术应该在不需要良好颜色的应用中产生更高的效率。所提出的Ba灯技术还应产生高效率和合理的颜色。Ba放电的理论研究是与欧司朗- sylvania公司理论和建模主管Graeme Lister博士密切合作进行的。实验研究完全在威斯康辛大学进行，并完全由美国国家科学基金会支持。第二项任务是继续发展辉光放电的动力学理论模型。计算机性能的进步使我们能够运行蒙特卡罗等离子体模拟来产生自一致的空间电荷势。这些模拟避免了所有常用辉光放电模型中的流体近似。这些自洽蒙特卡罗模拟还避免了等离子体鞘层跃迁时的任何内部边界条件。现在，模拟结果对于与其他更有效的流体和动力学模型进行比较是有用的。将强调自洽蒙特卡罗方法的继续发展，包括引入多步电离和气体加热，以及与实验结果更直接的比较

9988282LawlerContinued research on discharge plasmas for use as light sources is proposed. This research is in close collaboration with industry. The first Task is to continue experimental and theoretical investigations of barium (Ba) glow discharge plasmas for use as light sources. Barium has crucial advantages as a radiating atom in a glow discharge with an inert gas buffer. Barium has the required vapor pressure of 1 to 20 mTorr at achievable temperatures, it has a low excited configuration with a resonance level at an energy less than half of the ionization potential, and it has its dominant resonance line at the peak of the efficacy curve. The primary disadvantage of barium vapor in a lighting application is that barium is quite reactive. These studies of Ba discharges could lead to an entirely new lighting technology analogous to the low pressure sodium (Na) technology introduced in the 1960's. Low pressure Na lamps currently achieve the highest luminous efficacy of any commercially available lighting product, but unfortunately these lamps produce nearly monochromatic light. The proposed Ba lamp technology should yield a higher efficacy in applications not requiring good color. The proposed Ba lamp technology should also produce a high efficacy with reasonable color. The theoretical investigation of Ba discharges is in close collaboration with Dr. Graeme Lister, Head of Theory and Modeling at OSRAM-SYLVANIA INC. The experimental studies are entirely at the University of Wisconsin and are entirely supported by NSF.The second Task is to continue development of kinetic theory models of glow discharges. Advances in computer performance have enabled us to run Monte Carlo plasma simulations to generate Self-Consistent space charge potentials. These simulations avoid all of the fluid approximations in commonly used glow discharge models. These Self-Consistent Monte Carlo simulations also avoid any internal boundary conditions at the plasma-sheath transition. The simulation results are useful now for comparison to other, more efficient fluid and kinetic theory models. Continued development of the Self-Consistent Monte Carlo method including the introduction of multi-step ionization and gas heating, and more direct comparison to experimental results will be emphasized.***