| 摘要 |
<p>The electron source of an electron beam apparatus comprises a cathode wire which is to be heated by a laser beam and which is to be displaced in the wire direction. This cathode wire has a thickness of from 10 to 30 microns. By applying a field strength of 105 to 106 KV/m to the heated wire tip and by controlling the laser intensity and the wire feed during operation by a signal derived from the emission of the wire tip, a tip is produced on the wire end having a curvature radius of approximately 1 micron. At a temperature just below the melting temperature of the wire a stable temperature field emission having a current density of up to better than 104 A/cm2 is thus realized.</p> |
