Improvised Explosive Devices in Iraq:Countermeasures using an

Energetic Electron Beam

MIDN 1/C GonzalesMIDN 1/C Reichl

United States Naval AcademyMechanical Engineering Department

2006

Advisors:Prof. Martin Nelson, Mechanical Engineering Department

Visiting Prof. James Ziegler, Aerospace Engineering Department

This work has been supported by:Scott StewardU. S. Department of DefenseNaval Explosive Ordnance Disposal Technology DivisionNaval Support Facility Indian Head

Current Project Status• Beam extracted through thick Be window.

• Beam current about 50 nA/cm2

• Seven EOD targets destroyed with less than 200nC in less than 5 seconds.

• Targets shown to be destroyed by beams as low as 3 MeV.

Current goal is extraction through very thin window to allow beam to neutralize electronics at 30’.

Experiments with e-Zapper

Some targets packed with shot-gun shells and bullets to simulate nearby explosives.

Temperature rise in explosives calculated to be less than 1 oC.

No detonation was noted for beam currents >10x that which deactivated the electronics.

Experiments with e-Zapper

Project Statement

• 18-25 MeV electron beam– Effective Range = 270 feet– Uses a linear accelerator (LINAC)– LINAC vacuum = 10-9 Torr

Project concerns Exit window for E-beam from vacuum to atmosphere.a

Linear Accelerator

Plasma Window

• Developed by Acceleron Inc. and by Brookhaven National Laboratory

This device is under active investigation by the Naval Research Labs. Their preliminary report is due by 1/1/2007.

Hollow Rotating Shaft

• Combination of:– Metal barrier– Hollow rotating shaft