When running an e-gun for vacuum deposition, lots of thermal energi can be created. Usually  a coating plant can have an electron beam acceleration of 1Amp current at 10kV. This mean that 10kW of termal power are put in any target material that breaks the electron. Even thet best know material are easily evaporated. Carbon, tungsten, palladium or anything else can  be turned into gas phase.  A powerfull ray gun could be made luckily this could only work in the vacuum in space. However if a vacuumchamber is avalible  the purest known welding  can be made,  evaporation of material into thin films. melting of everything.




A water cooled crucible must be used othervise the whole interior could be melted.The gun is controlled
by magnet fields. But if the electron gun is aimed wrong and miss the crucible. Bad things can happens.
In this image the gun has hit a steel plate instead of the crucible.  The eletron gun can in seconds drill
 hole in anything. The Worst Case Scenario is if the elecron gun hits the chamber wall.