神光Ⅱ高功率钕玻璃片状放大器接地实验研究

Research of Grounding of High Power Nd:Glass Disk Amplifier of SG Ⅱ

实验研究了高功率片状放大器不接地(悬浮状态)时感应电压的变化规律,结果表明:感应电压的大小主要受到金属腔体与氙灯之间的分布电容、放大器充电电压以及氙灯数量的影响;腔体之间不产生直接影响关系。实验研究了放大器在多种接地方式下的感应特性,提出了放大器内外腔电一体化并整体接地的接地方案,并将其成功应用到了神光Ⅱ第9路350mm片状放大器中,从根本上消除了放大器内部电击穿的可能性,并将放大器的感应电压降低到悬浮状态下的18%,提高了片状放大器运行可靠性和安全性,同时有助于改善放大器的紧凑性和洁净度。采用这种接地方案以来,350mm放大器可靠运行400多发次,未出现电击穿或干扰现象。

The characteristics of the induced voltage of the high power disk amplifier, which is not grounding （suspended）, is researched experimentally. Results show that the peak value of the induced voltage is dominated by the capacitance between the flash lamp and the cavity and the number of flash lamps in the amplifier, and the independent cavities don＇t affect each other directly. Exprimental study on induction properties of the amplifier under a variety of grounding methods is conducted, and a grounding plan of wholly grounding the amplifier with the internal and external cavities electrically integrated is demonstrated, which is successfully applied to the 4350 mm disk amplifier of the ninth beam of SG 1I. The possibility of electrical breakdown inside the amplifier is eliminated radically, and the induced voltage of the amplifier is reduced to 18 % of that when the amplifier is suspended. As a result, the reliability and safety of the disk amplifier are improved obviously, the compactness and cleanliness of the amplifier are also improved simultaneously. Since this grounding plan is adopted, the 4350 mm amplifiers have operated reliably and safely for more than 400 shots without any electrical breakdown and interference.