发明授权
US06566663B1 Charged-particle-beam optical components and systems including ferrite exhibiting reduced image displacement from temperature fluctuations 失效
带电粒子束光学元件和系统包括铁氧体,其表现出从温度波动减小的图像位移

  • 专利标题: Charged-particle-beam optical components and systems including ferrite exhibiting reduced image displacement from temperature fluctuations
  • 专利标题(中): 带电粒子束光学元件和系统包括铁氧体,其表现出从温度波动减小的图像位移
  • 申请号: US09788123
    申请日: 2001-02-16
  • 公开(公告)号: US06566663B1
    公开(公告)日: 2003-05-20
  • 发明人: Koichi KamijoShinichi KojimaKatsushi NakanoKazuya Okamoto
  • 申请人: Koichi KamijoShinichi KojimaKatsushi NakanoKazuya Okamoto
  • 优先权: JP2000-041521 20000218; JP2000-041522 20000218; JP2000-082634 20000323
  • 主分类号: H01J37141
  • IPC分类号: H01J37141
Charged-particle-beam optical components and systems including ferrite exhibiting reduced image displacement from temperature fluctuations
摘要:
Charged-particle-beam (CPB) optical components (e.g., electromagnetic lenses and deflectors) are disclosed that exhibit very low to no image displacement or loss of focus accompanying changes in temperature of the optical components during use. An optical component includes a unit of ferrite (typically in a ferrite stack). The ferrite is configured to exhibit substantially no permeability change with a change in temperature relative to normal operating temperature, thereby maintaining image displacement caused by permeability changes to below a predetermined threshold. As the ferrite temperature T rises to T′, the saturation magnetic flux density Bs of the ferrite decreases while the initial permeability &mgr;i increases. Thus, the initial magnetization curves of the ferrite intersect at a particular magnetic field intensity H, which exhibits substantially no change from T to T′. With HAC being the particular magnetic field intensity, the ferrite is selected so that the magnetic field intensity acting on the ferrite during operation is near HAC.
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