# Physics307L F09:People/Lancaster/Notebook/070917

--Michael T. Lancaster 17:29, 17 September 2007 (EDT)Electron Diffraction

Now with the apparatus working we begin to take data.

Erron's measurements

Diameters ( outside first maximum) (outside second maximum) Voltages

```      (mm)                              (mm)              (kV)
32.30                            55.43              3.12
29.76                            51.10              3.30
28.55                            49.30              3.50
29.10                            47.80              3.60
28.63                            48.90              3.70
28.60                            48.20              3.80
26.60                            46.33              3.90
27.20                            46.90              4.00
28.00                            47.70              4.10
26.90                            47.20              4.20
27.10                            46.40              4.30
24.80                            45.70              4.40
26.20                            43.30              4.50
26.00                            42.40              4.60
26.50                            41.90              4.70
24.10                            41.40              4.80
24.10                            42.90              4.90
24.20                            41.40              5.00
```

--Michael T. Lancaster 17:29, 17 September 2007 (EDT)

Mike's Measurements ( outside first maximum) (outside second maximum) Voltages

```      (mm)                              (mm)              (kV)
```
```       30.53                           53.14               2.9
30.42                           53.01                3
29.85                           49.4                3.1
29.71                           49.23               3.2
28.75                           49.05               3.3
28.71                           48.32               3.4
27.93                           48.95               3.5
28.33                           47.92               3.6
28.95                           46.83               3.7
26.62                           46.42               3.8
26.16                           45.65               3.9
25.94                           45.37               4.0
25.82                           44.97               4.1
24.94                           43.25               4.2
23.96                           42.22               4.3
23.50                           42.70               4.4
23.78                           41.32               4.5
23.16                           42.27               4.6
22.28                           41.89               4.7
22.11                           41.69               4.8
21.95                           41.16               4.9
21.57                           40.55               5.0
```

## Off center aberration

The question was posed whether or not the diameter of the rings would be effected by the position of the center of the rings. To determine how much error there is in this we took several measurements.

On center

inner ring (mm) outer ring (mm) V 1) 30.29 48.3 3.8kV

```Off center
```

inner ring (mm) outer ring (mm) V

1)(18mm) 26.61 47.5 3.8 2)(7.46mm) 27.32 45.07 3.8 3)(11.07mm) 26.61 47.2 3.8 4)(5.03mm) 28.04 48.2 3.8