Degenerate ground-state conjugated polymers exhibit large third-order nonlinear optical susceptibilities, including substantial two-photon absorption. With the use of a machine architecture suited to these material properties, ultrafast optical processors are possible. A four-wave mixing optical correlator was built with an air-stable, processable, degenerate ground-state conjugated polymer, poly(1,6-heptadiester). The continuously updatable processor correlates two 5000-pixel images in less than 160 femtoseconds, achieving peak processing rates of 3 x 10(16) operations per second.

Dense plasma focus (DPF) Z-pinch devices are sources of copious high energy electrons and ions, x-rays, and neutrons. Megajoule-scale DPFs can generate 10 12 neutrons per pulse in deuterium gas through a combination of thermonuclear and beam-target fusion. However, the details of the neutron production are not fully understood and past optimization efforts of these devices have been largely empirical. Previously, we reported on the first fully kinetic simulations of a kilojoule-scale DPF and demonstrated that both kinetic ions and kinetic electrons are needed to reproduce experimentally observed features, such as charged-particle beam formation and anomalous resistivity. Here, we present the first fully kinetic simulation of a MegaJoule DPF, with predicted ion and neutron spectra, neutron anisotropy, neutron spot size, and time history of neutron production. The total yield predicted by the simulation is in agreement with measured values, validating the kinetic model in a second energy regime. V C 2014 AIP Publishing LLC. INTRODUCTIONWe describe here the first fully kinetic simulation of a MegaJoule-scale dense plasma focus (DPF). 1-4 This simulation is appreciably more computationally intensive than kinetic modeling of kilojoule-scale devices, 5,6 due to the greater spatial scales involved and the smaller time-step needed to resolve the higher electron cyclotron frequencies associated with the higher plasma current. The neutron yield predicted by this simulation is consistent with measured neutron yields, now validating this kinetic model in a second energy/current regime.A DPF consists of two coaxially located electrodes with a high-voltage source at one end ( Figure 1). In the presence of a low-pressure gas, the high-voltage source induces a surface flashover and the formation of a current-conducting plasma sheath across an insulator at the upstream end of the DPF. During the "run-down" phase, the current sheath is accelerated down the length of the electrodes by magnetic pressure, ionizing, and sweeping up neutral gas as it accelerates. When the plasma sheath reaches the end of the inner electrode, a portion is pushed radially inward during the "run-in" phase. When the leading-edge of the current sheath reaches the axis, it "pinches" the plasma to create a hot, dense region that emits high-energy electron and ion beams, x-rays, and (in the presence of D or D-T) neutrons. 4 In addition to fluid modeling, previous work has included a non-self-consistent test particle approach to access kinetic effects, 7-11 kinetic simulations of a Z-pinch with scaled ion-electron mass ratio, 12 and kinetic simulations of a conventional gas-puff Z-pinch. 13 We previously reported on the first fully kinetic model of a kJ-scale DPF Z-pinch device, including electrode boundaries, and demonstrated self-consistent production of high-energy charged particles and neutron production 5 as well as a detailed benchmark of the model with experiments. 6 SIMULATION AND EXPERIMENTAL SET UPThe simulation set-up is briefly summarized here: calc...

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We present two high bandwidth data transmission and recording systems for the measurement of transient signals during pulsed power and laser produced plasmas. These systems use fiber optic cables to transmit analog data over long distances to high bandwidth digitizing oscilloscopes. One system is based on the direct modulation of a laser diode and has a bandwidth of 1.5 GHz. The other system is based upon a fiberoptic Mach-Zehnder modulator and has a bandwidth of 12 GHz, and is limited by the photo receiver. The signals are recorded on commercial digitizing oscilloscopes that have approximately 6 effective bits. The transmission systems use many off-the-shelf components from the telecommunications industry and thus have a high reliability and a moderate cost. Results from recent measurements will be presented. Investigation of the reduction in optical transmission by the fibers during exposure to high dose radiation will also be discussed. Introduction: