Development of Versatile Environmental Cell for Electron Microscope

封闭式环境池（EC）已用于标准电镜观察水化样品。基于这种封闭型电池的设计，开发了多用途的膜密封型EC。（1）密闭型EC的改进和EC中气体压力估算的确认密闭型EC是新设计的，其气体层厚度控制在0 ~ 0.2mm之间，以进行高分辨率的观测和保持非常薄的液体层。对于封闭型EC，密封膜是电池最重要的组成部分，因为当EC在大气条件下封闭时，它必须承受高于大气压力的压力。研制出了高耐压、高电子透过率的最佳封孔膜。为了提高电致变色实验的效率，我们还制作了密封膜耐压测试装置 ...更多信息 离子观察，在密封电池之前，制造预抽空单元以将气体压力设定为低于大气压。电池中气体层的厚度可以从作为电子路径的质量厚度的函数绘制的透射率值来估计，该电子路径包括两个密封膜和气体层。该方法可用于在接近自然的环境中对生物样品进行观察时，对池内液层厚度的估算。（2）多用途膜密封型环境电池和气体控制单元的开发为了实用化，改进了膜密封型EC的结构和气体压力控制系统。通过减少EC的组件，EC的组装和操作变得容易。另外，由于密封膜的耐压性好，可以简化气体压力的控制过程，因此我们设计了一种新的气体控制装置，使操作更加简单。为了使EC具有更广泛的用途，我们制作了小型电极单元，并将其安装在EC中。气体循环管道可用作导线的通道，并可在EC中形成一定的电场。通过使用该电极单元，可以有效地收集电子照射到EC中的气体分子上而产生的离子，该技术不仅可以在EC中设定气体环境，还可以设定某些液体环境，并且可以通过平衡EC中的气体供给和排出之间的速度来控制液体层的厚度。这一技术必将成为水化试样原位观测的有用工具。少

The closed type environmental cell (EC) has been put into practical use for observing the hydrated specimens with the standard electron microscopes. Based on this design of the closed type cell, the film-sealed type EC for versatile use has been developed.(1)Improvement of the closed type EC and confirmation of the estimation of the gas pressure in the ECThe closed type EC was newly designed to control the gas layer thickness from 0 to 0.2mm for observation with high resolution and for holding very thin liquid layer. For the closed type EC, the sealing film is the most important component of the cell because it must withstand the pressure higher than the atmospheric pressure when the EC is closed in the atmospheric condition. We developed the method for the best sealing film with high withstanding pressure and high electron transmittance. We also made the device for testing the withstanding pressure of the sealing films for improving the efficiency of the EC experiment.For high resolut … More ion observations, a pre-evacuation unit was made to set the gas pressure lower than the atmospheric pressure before sealing up the cell. The thickness of the gas layer in the cell can be estimated from the transmittance value plotted as the function of the mass thickness of the electron path, involving two sealing films and the gas layer. This method may be applied to estimate the thickness of the liquid layer in the cell for observing the biological specimens in the nearly natural environment.(2)Development of the film-sealed type environmental cell for versatile use and the gas control unitFor the practical use, the configuration of the film sealed type EC and the gas pressure control system were improved. By reducing the components of the EC, it became easy to assemble and handle the EC. In addition to this, the sealing film of high withstanding pressure could make the procedure of controlling the gas pressure in the EC simple, so we made a new gas control device to make the operation easy.For versatile use of the EC, small electrode unit was made and fitted into the EC. The pipes for gas circulation can be used as the passages for the conducting wires and some electric field can be made in the EC. With the use of the electrode unit, it was confirmed that the ions, produced by the electron irradiation to the gas molecules in the EC, can be collected efficiently.This technique can set not only the gas environment, but also some liquid environment in the EC and the thickness of the liquid layer can be controlled by balancing the speed between supplying and evacuating the gas in the EC. This technique must be useful tool for in-situ observation of hydrated specimens. Less