WELDING ELECTRON BEAM ANALYZER

• The space current density distribution has the significant effect on the weld penetration, weld width, and quality of electron beam welds.
• In our electron beam analyzer high-power electron beams are analyzed by very fast (~1 km/s) deflection the beam over the edge of the flat sensor - tungsten plate. Beam current is measured in a circuit of this insulated sensor.
• Main area of our analyzer application is simple-to-use analysis of powerful electron beams, which are formed by the disk cathodes.

Fig.1. Block diagram of the machine with the electron beam analyzer 1 - electron beam gun; 2 - insulated flat sensor; 3 - massive copper body; 4 - 40 MHz, 8 - bit A/D converter; 5 - generator of deflecting pulses; 6,7 - D/A converters; 8 - electron beam analyzer; 9 - main computer; 10 - gun power supply.

The current density distribution is a function of a speed of a current increase. As a result of the calculations a computer gives a distribution of the beam current density. Therefore, by changing the focus it is possible to get a lengthwise section of the beam along its axis, to define the position of the beam focus, the distribution and values of the beam current density.

Fig.2. Longitudinal sections of the welding electron beams, formed by new (above) and utilized (48 hrs) cathode (below) with the requirement: Replace cathode , because the focus position and current density are changed essentially.

  DESIGN

The sensor and copper body are located in special position of the vacuum chamber. Prior to the welding, an operator gives the command to move gun in the position of the beam diagnostics. Electron beam analyzer is assembled inside industrial 19 rack / panelmount workstation with added A/D and D/A converters and deflecting pulses generator.

  TECHNICAL DATA