We examine two interrelated questions. How and where do we need to deploy nuclear detection portals in the real world? On the basis of which physical techniques should we design the technology to use in these portals? Today's national initiatives like the 9/11 Commission Act for scanning 100% of cargo at foreign ports of origin may be useful for interception of smuggled materials that are already assumed to be in transit -- by simply creating a roadblock for smuggling on high traffic routes, this does not get us any closer to dissuading adversaries from attacking by other means. Today's programs ignore the options (loopholes) within reach of the adversary that use alternative routes or countermeasures the attacker can employ against the detection technology. Loopholes can come as technical countermeasures usable against today's technology like passive gamma detection (shielding, fractionation) or against future technology like cosmic muon detection (dispersion, spreading). Loopholes may also be present in the form of transportation pathways not secured by any detection technology (private jets, sailboats, luxury cruise ships, and so on). In this talk, we discuss transportation loopholes and technical countermeasures in planned US initiatives using drive-thru nuclear detection portals for intercepting uranium. In addition to well-known countermeasures like shielding, we identify a novel countermeasure to cosmic muon detection based on horizontal spreading or dispersion. We show how to integrate passive gamma, neutron, muon, and active neutron detection techniques to make reliable detection portals (RDPs) invulnerable to simple countermeasures. We show where RDPs would need to be deployed around metropolitan areas and military bases to complement the national border, quantify how many RDPs would be required based on traffic flows, and define RDP specifications.

Devabhaktuni Srikrishna’s publications and patents have spanned quantum computing, parallel computing, wireless data communications, and nuclear detection. He holds a BS in Mathematics from the California Institute of Technology and an MS in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology. He was formerly Chief Technology Officer and a Founder of Tropos Networks (2000-2007). Tropos develops and manufactures wireless mesh routers for creating Wi-Fi service across metro areas currently operating in over 500 cities worldwide.

Thomas A. Tisch is a private high tech investor with operating and venture capital experience. In his career, he served as a partner at Portola Venture Fund, an initial investor in 3Com, and Software Publishing Corp and later at MBW Management where his investments included Netrix, Stratacom and Stac Electronics. Among operating roles, he was I instrumental in Etrade pioneering Internet brokerage as Vice President of Trade*Plus as it was known then. Mr. Tisch holds a BS in Engineering from the California Institute of Technology (1961), an MS EE from Stanford University and an MBA from the Stanford Graduate School of Business.

Narasimha Chari is the Founder and Chief Architect of Tropos Networks where he has been responsible for developing Tropos Networks' core intellectual property, including the design and development of the company's wireless networking and routing protocols. Among other honors, Mr. Chari was recognized by MIT Technology Review magazine in 2005 as one of the Top 35 Innovators under the age of 35. He has performed research, published papers and disclosed patents in a variety of areas of mathematics, physics, wireless networking and nuclear detection. Mr. Chari holds a BS in Mathematics and Economics from the California Institute of Technology and an AM in Physics from Harvard University.