Keffer C E, Torr M R, Zukic M, Spann J F, Torr D G, Kim J
Appl Opt. 1994 Sep 1;33(25):6041-5. doi: 10.1364/AO.33.006041.
Advances in vacuum ultraviolet thin-film filter technology have been made through the use of filter designs with multilayers of materials such as Al(2)O(3), BaF(2), CaF(2), HfO(2), LaF(3), MgF(2), and SiO(2). Our immediate application for these filters will be in an imaging system to be flown on a satellite where a 2 × 9 R(E) orbit will expose the instrument to approximately 250 krad of radiation. Because to our knowledge no previous studies have been made on the potential radiation damage of these materials in the thin-film format, we report on such an assessment here. Transmittances and reflectances of BaF(2), CaF(2), HfO(2), MgF(2), and SiO(2) thin films on MgF(2) substrates, Al(2)O(3) thin films on fused-silica substrates, uncoated fused silica and MgF(2), and four multilayer filters made from these materials were measured from 120 to 180 nm beforeand after irradiation by 250 krad from a (60)Co gamma radiation source. No radiation-induced losses in transmittance or reflectance occurred in this wavelength range. Additional postradiation measurements from 160 to 300 nm indicates 2-5% radiation-induced absorption near 260 nm in some of the samples with MgF(2) substrates. From these measurements we conclude that far-ultraviolet filters made from the materials tested should experience less than 5% change from exposure to up to 250 krad of high-energy radiation in space applications.
通过使用由诸如Al(2)O(3)、BaF(2)、CaF(2)、HfO(2)、LaF(3)、MgF(2)和SiO(2)等多层材料构成的滤光片设计，真空紫外薄膜滤光技术取得了进展。我们对这些滤光片的直接应用将是在一个搭载于卫星上的成像系统中，该卫星的2×9 R(E)轨道会使仪器受到约250千拉德的辐射。由于据我们所知，此前尚未对这些薄膜形式材料的潜在辐射损伤进行过研究，我们在此报告这样一项评估。在来自(60)Co伽马辐射源的250千拉德辐射照射前后，测量了MgF(2)衬底上的BaF(2)、CaF(2)、HfO(2)、MgF(2)和SiO(2)薄膜、熔融石英衬底上的Al(2)O(3)薄膜、未镀膜的熔融石英和MgF(2)以及由这些材料制成的四个多层滤光片在120至180纳米范围内的透过率和反射率。在该波长范围内未发生辐射引起的透过率或反射率损失。从160至300纳米的额外辐射后测量表明，一些带有MgF(2)衬底的样品在260纳米附近有2 - 5%的辐射诱导吸收。从这些测量结果我们得出结论，在空间应用中，由测试材料制成的远紫外滤光片在受到高达250千拉德的高能辐射照射后，其变化应小于5%。
