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Improvised Explosive Devices in Iraq: Countermeasures using an Energetic Electron Beam MIDN 1/C Gonzales MIDN 1/C Reichl United States Naval Academy Mechanical Engineering Department 2006 Advisors: Prof. Martin Nelson, Mechanical Engineering Department
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Improvised Explosive Devices in Iraq: Countermeasures using an Energetic Electron Beam MIDN 1/C Gonzales MIDN 1/C Reichl United States Naval Academy Mechanical Engineering Department 2006 Advisors: Prof. Martin Nelson, Mechanical Engineering Department Visiting Prof. James Ziegler, Aerospace Engineering Department This work has been supported by: Scott Steward U. S. Department of Defense Naval Explosive Ordnance Disposal Technology Division Naval 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.
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
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
Beryllium Window Temperature Increase (Note : Temp. Rise is Independent of Be Thickness) • Assume a ROTATING FOIL at radius 1”, with an electron beam diameter of 3mm. • The beam track = 160 mm. This is 53 beam diameters (3 mm beam). • Beryllium Melting Point = 1287 °C • Temperature rise to ¼ melting = 316 °C
Stainless Steel T304 Wire drawn Weave Highly Transparent “Optical Grade” ISO 9044 General Mesh Properties
Roughing Pump Rigaku Rotating Shaft 4 way Nipple Mesh and Foil 2 way Nipple Dual Flanges for Foil Fast Acting Valve LINAC Offset Flange High Vacuum Pump E-Zapper Vacuum System and Output Flange (Completed June, 2006)
E-Zapper StatusAugust, 2006 • Complete new vacuum system assembled and tested. • Fast-acting valve protective system assembled and tested. • Rotary output flange (Rigaku) fabricated, but is leaky. Returned (3rd time) to manufacturer. • Alignment and Focusing system completed. • NRL evaluation of Plasma Window is not expected until Jan., 2007.