Nonrenewable resources are distributed unevenly throughout the world. Throughout history, the ability to access nonrenewable resources has been a source of geopolitical tension. Modern civilization is increasingly dependent on unevenly distributed resources that are traded globally. This cooperation has helped to increase resource security by increasing affordable access to resources around the world. The continued accessibility of nonrenewable resources is the key uncertainty to security over the next 15 to 25 years. Increased global demands for nonrenewable resources, fragility to resource shocks, and geopolitical upheavals may threaten nonrenewable resource security. A reduction in resource security could exacerbate defense and economic vulnerabilities to resource shocks, and increased fears of resource insecurity could drive conflict over resources leading to geopolitical upheavals. National security organizations can help build resource security by making investments that create resilience to resource shocks. They can also promote international cooperation that builds trust. Together, increased resilience to shocks and increased global trust should help reduce fears of resource insecurity and expand global cooperation on resource issues, thereby bolstering resource security.
“Technology empowerment” means that innovation is increasingly accessible to ordinary people of limited means. As powerful technologies become more affordable and accessible, and as people are increasingly connected around the world, ordinary people are empowered to participate in the process of innovation and share the fruits of collaborative innovation. This annotated briefing describes technology empowerment and focuses on how empowerment may create challenges to U.S. national security. U.S. defense research as a share of global innovation has dwindled in recent years. With technology empowerment, the role of U.S. defense research is likely to shrink even further while technology empowerment will continue to increase the speed of innovation. To avoid falling too far behind potential technology threats to U.S. national security, U.S. national security institutions will need to adopt many of the tools of technology empowerment.
Stable self-channeling of ultra-powerful (P{sub 0} - 1 TW -1 PW) laser pulses in dense plasmas is a key process for many applications requiring the controlled compression of power at high levels. Theoretical computations predict that the transition zone between the stable and highly unstable regimes of relativistic/charge-displacement self-channeling is well characterized by a form of weakly unstable behavior that involves bifurcation of the propagating energy into two powerful channels. Recent observations of channel instability with femtosecond 248 nm pulses reveal a mode of bifurcation that corresponds well to these theoretical predictions. It is further experimentally shown that the use of a suitable longitudinal gradient in the plasma density can eliminate this unstable behavior and restore the efficient formation of stable channels.
A theoretical analysis of laser-driven collisional ejection of inner-shell electrons is presented to explain the previously observed anomalous kilovolt L-shell x-ray emission spectra from atomic Xe cluster targets excited by intense sub-picosecond 248nrn ultraviolet radiation. For incident ponderomotively-driven electrons photoionized by strong above threshold ionization, the collisional ejection mechanism is shown to be highly l-state and significantly n-state (i.e. radially) selective for time periods shorter than the collisional dephasing time of the photoionized electronic wavefunction. The resulting preference for the collisional ejection of 2p electrons by an ionized 4p state produces the measured anomalous Xe(L) emission which contains direct evidence for (i) the generation of Xe{sup 27+}(2p{sup 5}3d{sup 10}) and Xe{sup 28+}(2p{sup 5}3d{sup 9}) ions exhibiting inner-shell population inversion and (ii) a coherent correlated electron state collision responsible for the production of double 2p vacancies. For longer time periods, the selectivity of this coherent impact ionization mechanism is rapidly reduced by the combined effects of intrinsic quantum mechanical spreading and dephasing--in agreement with the experimentally observed and extremely strong {minus}{lambda}{sup {minus}6} pump-laser wavelength dependence of the efficiency of inner-shell (2p) vacancy production in Xe clusters excited in underdense plasmas.
A highly selective, coherent impact ionization mechanism is proposed for the efficient generation of inner-shell population inversion in laser-driven plasmas. The theoretical analysis is consistent with observed L-shell (2p{l_arrow}3d) emission spectra from laser-excited Xe clusters.