IMPROVEMENT TO CCD CAMERA PERFORMANCE ON IVEM

描述(改编自申请人的摘要)：电荷耦合 器件(CCD)相机在电子显微镜中得到了广泛的应用。 它们提供的图像和衍射数据的可用性比 摄影胶片，这种周转时间的改善使得 极大地提高了标本鉴定的效率，显微镜 操作和自动化，以及数据记录。对于某些类型的工作， 用电荷耦合器件采集的数据比用胶片记录的数据质量更高。 然而，当显微镜的性能受到严重影响时， 运行在大约100千伏左右，这是由于 闪烁体，它降低了信号电平，并增加了横向 闪烁体内电子的散射，这降低了 决议。这些效应加在一起可以产生探测量子 效率(DQE)远远低于胶片，而且确实太低 低剂量的蛋白质成像等工作。浅谈中间电压的使用 工作在300-400千伏的电子显微镜(IVEM)随着 更高的加速电压的许多优点变得更加广泛 因此，这些显微镜上的电荷耦合器件的性能变得越来越好 有局限性的。调查员计划克服表现不佳的问题 通过在研究之前减速电子来实现IVEM上的ccd摄像机 摄像机。调查员将安装ccd，使其能够漂浮。 到200千伏，这样当显微镜工作在300千伏时，他将 获得IVEM的优势，但摄像头的性能将与 在一台100千伏的显微镜上。我们会进一步改善 闪烁体可产生更好的信号和分辨率特性 比目前可用的更多。这些适应将产生重大的 工作中的好处，从高分辨率结构研究 膜蛋白和病毒对细胞的三维研究 超微结构。

DESCRIPTION (Adapted from the applicant's abstract): Charged-coupled device (CCD) cameras have found wide application in electron microscopy. They provide much faster availability of image and diffraction data than photographic film, and this improvement in turnaround time has allowed a tremendous increase in the efficiency of specimen evaluation, microscope operation and automation, and data recording. For some types of work the data collected with a CCD is of higher quality than when recorded on film. However, the CCD performance is seriously compromised when the microscope is operated much about 100 kV, due to the decrease in efficiency of the scintillator, which decrease the signal level, and increased lateral scattering of the electrons within the scintillator, which decrease the resolution. Together these effects can produce a detective quantum efficiency (DQE) which is far below that of film and indeed too low for work such as low-dose imaging of proteins. The use of Intermediate Voltage Electron Microscopes (IVEMs) operating at 300-400 kV is increasing as the many advantages of the higher accelerating voltage become more widely recognized, so the CCD performance on these microscopes is becoming more of a limitation. The investigator plans to overcome the poor performance of CCD cameras on IVEMs by decelerating the electrons before they research the camera. The investigator will mount the CCD so that it can be floated to 200 kV, so that when the microscope is operated at 300 kV he will obtain the advantages of the IVEM but the camera will perform as well as on a 100 kV microscope. Further improvements will be made to the scintillator to produce even better signal and resolution characteristics than currently available. These adaptations will produce substantial benefits in work ranging from high-resolution structural studies of membrane proteins and viruses to the three dimensional study of cell ultrastructure.