8.1 Alignment procedure for Projection

For a given magnification, the LPR2 value for both image mode and slit mode must be the same.

Detector Panel: Standard Image Presets

Detector Panel: Standard Slit Presets

8.1.1 Instrument conditions

Instrument condition: FA #1 (1800μm), CA #1 (400 μm), Max area (Transfer preset) 150 μm, Entrance Slit full open (400μm) and Exit Slit full open (1200 μm).

It is previously needed to prepare a clear grid image on Image mode as it is shown below.

²⁸ Si ⁺ / ²⁸ Si ⁻ image on Si/Ta grid sample : secondary positive & negative mode

¹³³ Cs ⁺ image on Si/Ta grid sample : secondary positive mode

8.1.2 Alignment procedure

Setting DPRY

1. Open the MCP Image calibration box while keeping grid image on Image mode.

2. Increase LPR1 to have slit mode, if the beam is not wobbling at the same position between Image and Slit mode, recenter it using Mass field for horizontal centring and DPRY for vertical centring.

While increasing LPR1 value, the beam center moves to the left and upwards. => Need Mass and DPRY adjusting

3. Note that the previous procedure 2) can be simply performed by alternating both Image preset & Slit preset. Refer to the images below when DPRY is not correctly set.

<Image preset> (left) and <Slit preset> (right) alternating alignment with bidirectional arrow

4. After adjusting the Mass for horizontal centring and DPRY for vertical centring, both shapes should be set at the same position.

After Mass and DPRY adjusting, the beam center of image mode and Slit mode is same.