Acceleration Tubes

Acceleration Tube Applications

NEC’s all metal and ceramic acceleration tube assemblies are ideal for applications that require ultra-high vacuum capability in regions of high voltage or where a complete insulating barrier is required. Contact us to start an order.


All NEC acceleration tubes are insensitive to thermal shock and exhibit exceptional mechanical strength. They have been in use on a routine basis in very strenuous conditions for periods of over 40 years with no signs of degradation.

NEC offers two different styles of acceleration tubes, based on application:



General Purpose Acceleration Tube

GP tube assembly consisting of three sections, shown with a 250 kV open-air high voltage deck (safety cage removed) in a single stage AMS system


The GP acceleration tube section is designed for operation in clean, dry ambient air and is in use on all NEC open-air ion beam systems up to 500 kV.

Each section is conservatively rated at 75 kV, and multiple sections can be combined to achieve higher voltage.

The exterior field is defined by demountable potential distribution rings. Potential grading is provided by ten 150 Mohm resistors in series.


A non-magnetic version of the General Purpose Acceleration Tube is also available for the acceleration of low energy electron beams that are adversely affected by proximity of ferromagnetic materials.



High Gradient Acceleration Tube

S-Series column with high gradient acceleration tube assembly surrounded by equipontential rings

HG tube assembly shown in an S-series column, surrounded by equipotential rings


The HG acceleration tube section is designed for operation in high pressure SF6 gas. These tubes have been used in Pelletron accelerators ranging from below 1 MV to above 25 MV terminal potentials.

HG acceleration tubes are offered in several standard lengths, depending on the number of gaps. Each gap of the standard HG tube is rated at a conservative 30 kV when used in Pelletron accelerators. Typical tubes are 20 to 22 gaps long, for a combined voltage rating of up to 500 kV.

Like the GP tube, multiple HG tubes can be combined to achieve higher voltage. For use in Pelletron accelerators, potential grading is usually provided with a point to plane corona distribution system or resistor divider.


The HG tube is available with two diameter configurations:



Related Documents
Accel Tubes