IMPROVEMENT TO CCD CAMERA PERFORMANCE ON IVEM

描述（改编自申请人摘要）：电荷耦合 电子器件（CCD）照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，这种改进的周转时间允许 极大地提高了样品评估、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CCD收集的数据比记录在胶片上的数据质量更高。 然而，CCD性能严重受损时，显微镜 在大约100 kV的情况下运行，这是由于 闪烁体，这降低了信号水平，并增加了横向 闪烁体内的电子的散射，这降低了 分辨率这些效应结合在一起可以产生一个探测量子 效率（DQE）远低于胶片，实际上对于 例如蛋白质的低剂量成像。中间电压的使用 在300-400 kV下工作的电子显微镜（IVEMS）随着 更高加速电压的许多优点变得更加广泛 因此，这些显微镜上的CCD性能变得越来越重要。 一个限制。研究者计划克服表现不佳 通过在电子研究之前使电子减速， 镜头调查员将安装CCD，使其可以浮动 到200 kV，因此当显微镜在300 kV下操作时，他将 获得IVEM的优势，但相机的性能也会一样好 在100千伏的显微镜下。我们会进一步改善 闪烁体产生更好的信号和分辨率特性 比目前可用的。这些调整将产生大量的 从高分辨率的结构研究， 膜蛋白和病毒对细胞三维结构的影响 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.