後方磁界

post-magnetic field

[目次：レンズ系]

現在の透過電子顕微鏡では試料は対物レンズの中に置かれている。対物レンズの磁界で、試料より後方（中間レンズ側）に作られる磁界のこと。後方磁界での球面収差、色収差が像の分解能を決めるので、後方磁界は像形成において最も重要な部分。

In a modern electron microscope, a specimen is placed in the objective lens. The magnetic field produced below the specimen (at the intermediate lens side) is called "post-magnetic field." Since the spherical aberration and chromatic aberration of the post-magnetic field determine the image resolution, this field is the most important part for image formation.