Soft X-Ray Telescope

The Soft X-Ray Telescope (SXT) is designed to produce X-ray movies of solar flares with excellent angular and time resolution as well as full-disk images for general studies of the solar corona. The instrument uses a glancing incidence telescope of 1.54 m focal length which forms X-ray images in the 0.25 to 4.0 keV range on a 1024 x 1024 virtual phase charge coupled device (CCD) detector. A unique mirror of hyperboloids is used to achieve wide-field angular resolution superior to that of the more common paraboloid-hyperboloid design. A selection of thin metallic filters located near the focal plane provides the capability to separate different X-ray energies for plasma temperature diagnostics. A visible light image corresponding with the X-ray field of view is provided by a coaxially mounted visible-light telescope (called the aspect telescope) which forms its image on the CCD detector when the thin metallic filter is replaced b an appropriate glass filter. SXT has the following design capabilities: effective area: 78 sq. mm at 8 A, dynamic range > 10**7, time resolution of 0.5 to 2 s, angular resolution < 3 arc s FWHM at 8 A, spectral range 3 - 45 A. The aspect telescope is suitable for pointing determination within 1 arc s or better, for observing white-light flares and for helioseismology observations as well. SXT fits within an envelope 30 x 30 x 170 cm, and is provided with on-board computers for programmed operations. Acquisition of solar images is slaved to the current telemetry rate, either 32 kbps in flare mode or 4 kbps normally, so image cadence varies in a complex way with telemetry rate and observed plan. Full-frame images and partial-frame images centered on bright image areas are made, according to observing plan spceifications. The instrument operates during passage through the South Atlantic Anomaly, experiencing some "snow" distributed over the image.

软X射线望远镜（SXT）旨在生成具有卓越角分辨率和时间分辨率的太阳耀斑X射线电影，并可获得用于对太阳冕进行一般研究的全盘图像。该仪器采用焦距为1.54米的掠射望远镜，能够在0.25至4.0 keV的范围内，在1024 x 1024虚拟相移电荷耦合器件（CCD）探测器上形成X射线图像。一种独特的双曲面镜被用于实现宽视场角分辨率，其性能优于常见的抛物面-双曲面设计。位于焦平面附近的金属薄膜滤波器的选择，提供了分离不同X射线能量以进行等离子体温度诊断的能力。通过同轴安装的可见光望远镜（称为视向望远镜）提供与X射线视场相对应的可见光图像，该望远镜在更换为适当的玻璃滤波器时，在其CCD探测器上形成图像。SXT具备以下设计能力：有效面积在8 A时为78平方毫米，动态范围大于10^7，时间分辨率为0.5至2秒，角分辨率在8 A时小于3弧秒FWHM，光谱范围为3至45 A。视向望远镜适用于在1弧秒或更优的精度内进行指向确定，用于观察白光耀斑和进行日震学观测。SXT的尺寸为30 x 30 x 170厘米，并配备有用于程序化操作的机载计算机。太阳图像的获取与当前遥测率同步，在耀斑模式下为32 kbps，通常为4 kbps，因此图像帧率以复杂的方式随遥测率和观测计划而变化。根据观测计划规格，制作全帧图像和以明亮图像区域为中心的局部帧图像。在穿越南大西洋异常区期间，该仪器在图像上经历了一些分布的‘雪’。”}