JEM-2100plus: Current and Voltage Axis Alignment

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Note: This page was translated by AI from the Japanese original. In case of any discrepancy, the Japanese version shall prevail.

Original post date (Japanese version): June 22, 2024

Current Axis (Current Center) Alignment

💡 Keep the image from moving from the center of the fluorescent screen when changing the objective lens current (Focus)

When the excitation current of the objective lens is fluctuated, the electron microscope image expands and contracts spirally. This refers to the center of this expansion and contraction. Aligning the center of the current axis with the center of the fluorescent screen for image observation using a two-stage deflection system is called current axis alignment. Since the current fluctuation of the objective lens is small, voltage axis alignment is usually performed instead of current axis alignment. (Quoted from JEOL Transmission Electron Microscope Basic Glossary)

  1. [PANEL-R : Function : MAG1]In image observation mode
  2. [PANEL-R : MAG/CAM L] Magnification setting Appropriate magnification (e.g.: x100K)
  3. Beam centering
  4. Focusing (Coarse/Fine)
    1. [PANEL-R : STD FOCUS] Recall reference current
    2. [PANEL-R : Z△▽] Specimen height (Z) adjustment: Lower the contrast to the minimum
    3. [PANEL-R : OBJ FOCUS] Adjust to an easy-to-see focus near the true focus
  5. Brightness adjustment
    1. [PANEL-L : BRIGHTNESS] Brightness easy for observation: Expand the beam to about the same size as the screen
  6. [TB] Move the observation target (marker) to the center of the fluorescent screen using the trackball
  7. Objective Lens Wobbler On
    1. [TEM Center: Upper menu] Control → Wobbler
      1. Wobbler Controller (for JEM Administrators) will be displayed.
    2. [TC : Wobbler Controller : Object Lens] On
    3. The excitation of the objective lens fluctuates, and the image expands and contracts
  8. Current axis alignment
    1. [PANEL-L : DEF/STIG : BRIGHT TILT] or [TC : Alignment Panel : Deflector : Bright Tilt ] Select bright field illumination mode
    2. [PANEL-L/R: DEF/STIG-X/Y] Adjust with Beam Tilt so that the center of the image expansion/contraction coincides with the center of the fluorescent screen.
  9. Objective Lens Wobbler Off
    1. [TC : Wobbler Controller : Object Lens] Off

Voltage Axis (Voltage Center) Alignment

💡 Keep the image from moving from the center of the fluorescent screen when changing the accelerating voltage.

When the accelerating voltage is fluctuated with a high-voltage wobbler, the electron microscope image expands and contracts spirally. This refers to the center of this expansion and contraction. Aligning the center of the voltage axis with the center of the fluorescent screen for image observation using a two-stage deflection system is called voltage axis alignment. Since the high-voltage fluctuation is small (10-6 or less), this alignment can be said to be for inelastic scattering (plasmon scattering) by the specimen rather than for high-voltage fluctuation. This axis alignment is necessary for images at medium magnifications of 100,000x or less. (Quoted from JEOL Transmission Electron Microscope Basic Glossary)

  1. [PANEL-R : Function : MAG1]In image observation mode
  2. [PANEL-R : MAG/CAM L] Magnification setting Appropriate magnification (e.g.: x100K)
  3. Beam centering
  4. Focusing (Coarse/Fine)
    1. [PANEL-R : STD FOCUS] Recall reference current
    2. [PANEL-R : Z△▽] Specimen height (Z) adjustment: Lower the contrast to the minimum
    3. [PANEL-R : OBJ FOCUS] Adjust to an easy-to-see focus near the true focus
  5. Brightness adjustment
    1. [PANEL-L : BRIGHTNESS] Brightness easy for observation: Expand the beam to about the same size as the screen
  6. [TB] Move the observation target (marker) to the center of the fluorescent screen using the trackball
  7. HT Wobbler On
    1. [TEM Center: Upper menu] Control → Wobbler
      1. Wobbler Controller (for JEM Administrators) will be displayed.
    2. [TC : Wobbler Controller : HT] or [PANEL-R: HT WOBB] On
    3. The accelerating voltage fluctuates, and the image expands and contracts
  8. Voltage axis alignment
    1. [PANEL-L : DEF/STIG : BRIGHT TILT] or [TC : Alignment Panel : Deflector : Bright Tilt ] Select bright field illumination mode
    2. [PANEL-L/R: DEF/STIG-X/Y] Adjust with Beam-Tilt so that the center of the image expansion/contraction coincides with the center of the fluorescent screen.
  9. HT Wobbler Off
    1. [TC : Wobbler Controller : HT] or [PANEL-R: HT WOBB] Off

💡 Voltage axis or Current axis

*This post was created by an AI agent.