Producing KDP and DKDP crystals for the NIF laser
Producing KDP and DKDP crystals for the NIF laser
复制标题
DOI：
10.2172/14145
复制
发表时间：
1999-09
期刊：
影响因子：
--
通讯作者：
L. Atherton;A. Burnham;R. Combs;S. Couture;J. Yoreo;R. Hawley-Fedder;R. C. Montesant;H. Robey;M. Runkel;M. Staggs;P. Wegner;M. Yan;N. Zaitseva
中科院分区：
文献类型：
--
作者：
L. Atherton;A. Burnham;R. Combs;S. Couture;J. Yoreo;R. Hawley-Fedder;R. C. Montesant;H. Robey;M. Runkel;M. Staggs;P. Wegner;M. Yan;N. Zaitseva
NIF 的成本和物理要求确立了磷酸二氢钾 (KDP) 晶体的两个重要作用。 1. 为了从每单位闪光灯光和激光玻璃中提取更多的激光能量，NIF 采用了如图 1 所示的多通道架构。光被注入传输空间滤波器，首先穿过功率放大器，然后被引导至主放大器，在主放大器中经过四次通过，然后再通过功率放大器重定向到目标。为了实现主放大器的多次通过，包含 KDP 的普克尔斯盒旋转光束的偏振，使其透射或反射主激光腔内以布儒斯特角固定的偏振器。如果传输，光会从镜子反射并再次穿过腔体。如果被反射，它会通过功率放大器到达目标。金字塔面生长时的原始晶种。不幸的是，这种金字塔形的生长非常缓慢，大约需要两年的时间才能将晶体生长到 NIF 尺寸。为了提供更大的编程灵活性并从长远来看降低成本，我们开发了一种通常称为快速增长的替代技术。通过结合更高的温度和更高的生长溶液过饱和度，可以在 1 到 2 个月内从一个小“点”种子生长出 NIF 大小的晶锭。然而，仅生长足够大小的晶锭是不够的。必须小心防止生长溶液中的夹杂物和原子取代的 2 的掺入。ICF 的内爆在较短的波长下工作得更好，因为产生的热电子较少，从而预热燃料并使其更难以压缩。 Nova 和 NIF 均在光学寿命和内爆效率之间进行折衷，其工作频率是钕玻璃激光器 1053 nm 基频的三倍。这种三倍化是通过两种晶体实现的，一种由 KDP 制成，另一种由氘化 KDP (DKDP) 制成。第一个将两个 1053 nm 光子混合以产生 526 nm 光，第二个将剩余的 1053 nm 光子与 526 nm 光子组合以产生 351 nm 光。
The cost and physics requirements of the NIF have established two important roles for potassium dihydrogen phosphate (KDP) crystals. 1. To extract more laser energy per unit of flashlamp light and laser glass, the NIF has adopted a multipass architecture as shown in Figure 1. Light is injected in the transport spatial filter, first traverses the power amplifiers, and then is directed to main amplifiers, where it makes four passes before being redirected through the power amplifiers towards the target. To enable the multipass of the main amplifiers, a KDP-containing Pockels cell rotates the polarization of the beam to make it either transmit through or reflect off a polarizer held at Brewster's angle within the main laser cavity. If transmitted, the light reflects off a mirror and makes another pass through the cavity. If reflected, it proceeds through the power amplifier to the target. the original seed crystal as the pyramid faces grow. Unfortunately, this pyramidal growth is very slow, and it takes about two years to grow a crystal to NIF size. To provide more programmatic flexibility and reduce costs in the long run, we have developed an alternative technology commonly called rapid growth. Through a combination of higher temperatures and higher supersaturation of the growth solution, a NIF-size boule can be grown in 1 to 2 months from a small ''point'' seed. However, growing boules of adequate size is not sufficient. Care must be taken to prevent inclusions of growth solution and incorporation of atomically substituted 2. Implosions for ICF work far better at shorter wavelengths due to less generation of hot electrons, which preheat the fuel and make it harder to compress. Compromising between optic lifetime and implosion efficiency, both Nova and the NIF operate at a tripled frequency of the 1053-nm fundamental frequency of a neodymium glass laser. This tripling is accomplished by two crystals, one made of KDP and one made of deuterated KDP (DKDP). The first one mixes two 1053-nm photons to make 526-nm light, and the second one combines a residual 1053-nm photon with a 526-nm photon to make 351-nm light.