|
Tungsten Filament |
Lanthanum Hexaboride (LaB6) |
Field Emission |
|
|
Emission |
Thermionic |
Thermionic |
Field |
|
Operating vacuum |
10-4 - 10-5 |
10-6 - 10-7 |
10-9 - 10-10 |
|
Brightness (nA/cm2) |
10+4 - 10+5 |
10+5 - 10+6 |
10+7 - 10+9 |
|
Source size (µm) |
100 µm |
20 µm |
<10 nm |
|
Energy spread (eV) |
1-5 |
0.5 - 3 |
0.2 - 0.3 |
|
Probe current varies |
0.1 - 1.0% |
0.2 - 2.0% |
2 - 10% / min |
|
Operating life (hrs) |
> 20 |
> 100 (> 600) |
> 300 (> 2000) |
|
Cost (each) |
$12 |
$1,000 |
$1,500 |