THE 6 MV ACCELERATOR (ASCII VERSION)

This is a 6 mega-Volt (MV) electrostatic accelerator of modified NEC¹ design. It is a single-ended vertical machine that operates at negative terminal potential and has both accelerator and decelerator tubes. Electrostatic accelerators are often refered to as "van deGraaf Accelerators," the primary difference being NEC's use of pelletron charging chains instead of the old rubber belts and the use of sulfur hexafluoride (SF₆) insulating gas.

This accelerator is unique in being designed to operate with a high current recirculating electron beam. Recirculation permits operation at ampere current levels for tens of microseconds despite a charging current four orders of magnitude smaller.

The electrostatic accelerator has a number of significant advantages as an FEL beam source including:

• NO TEMPORAL MICROSTRUCTURE

  - narrow linewidth, long coherence length

  - no damage to optics or samples by intense peak powers

  - no critical resonator tuning

• ABSENCE OF STRONG TIME-DEPENDENT FIELD GRADIENTS

  - negligible energy spread

  - acceleration with minimum beam degradation, low emittance

  - static fields permit deceleration and collection of a beam with almost perfect efficiency

• SIMPLE RELIABLE OPERATION

  - it is a simple, reliable, self-contained, mechanical device that can be switched on or off with a minimum of fuss or bother

• Photo of Terminal (.gif)
• Electron Gun
• Accelerator Tube Section
• Focussing Solenoid
• Collector

¹ National Electrostatics Corp., Middleton, Wisconsin

updated 19-Jan-97 - GR - ramian@sbFEL3.ucsb.edu