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A series of experiments has been carried out on the S-300 pulsed power machine (3 MA, 0.15 Ohm, 100 ns), devoted to the study of a section of magnetically insulated vacuum transporting line (MITL), by the current flow density up to 500 MA/cm2, by the linear current flow density being up to 6 MA/cm. These parameters fairly correspond to those of the Sandia Laboratories’ conceptual project of IFE reactor based on the fast Z-pinch. The goals of experiments were as follows: 1) study of the near-electrode plasma and its effect on the energy transfer; 2) testing the 2-temperature MHD code NPINCH modeling the behavior of near-electrode plasmas. As a result, the conditions of plasma formation and reconnection of the MITL gap have been determined. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

High intensity pulsed electron beams are used to create bremsstrahlung x-ray sources for flash radiographic interrogation of dynamic experiments. Typical industrial sources operate below 200 GW/cm² intensities, while experimental requirements can demand above 50 TW/cm². Recent developments in pulsed power-driven high intensity electron beam systems have significantly increased these operating regimes, demonstrating 20 TW/cm², and computations predict successful extrapolation to higher intensities. Detailed studies of electron beam configurations, both theoretical and experimental, and the prognosis for each to increase to the required levels is discussed. [ABSTRACT FROM AUTHOR]

Uranium compounds exhibit a great variety of phenomena such as Pauli paramagnetism, quadrupolar and magnetic ordering, heavy fermion, and unconventional superconductivity. It is considered that these behaviors are closely related to the crystal structure, correlation among f-electrons, and the f-electron hybridization with conduction electrons. Photoelectron spectroscopy (PES) studies have been carried out on single crystals of the compounds UCoGa[sub5] and PuCoGa[sub5] in order to determine the details of their electronic structure. While PuCoGa[sub5] is a superconductor with a T[subc] of 18 K, and a gamma value of 77 mJ/mole K the Uranium counterpart shows neither significant magnetic nor enhanced mass characteristics. We present initial angle-integrated PES measurements for both the Uranium and Plutonium based compounds taken at photon energies accessible with a Helium lamp. Both samples were cleaned by laser ablation in a vacuum of ∼ 5x10[sup-11] Torr to remove surface oxides and contamination, and measurements made down to a temperature of ∼10K with an experimental resolution of-60 meV. The Pu compound results lean towards the characteristics of its Cerium counterpart, CeCoIn[sub5] (one of the Ce based family of heavy fermion superconductors), with significant electron correlations requiring a description beyond the one-electron approximation. The overall valence band characteristics are similar to those of other Pu materials with a peak at the Fermi level and another broader peak at approximately ∼1 eV, though the peak at the Fermi level is not as sharp as those observed in delta Plutonium or PuSb[sub2]. A comparison of the PuCoGa[sub5] data will be made with the 'mixed level' model (MLM) of Wills et al. and also Density Functional Theory (DFT). The Uranium compound similarly exhibits a peak at the Fermi level and one at around ∼1 eV though the ratio of the intensities of the two peaks differ from those of the Pu counterpart. Uranium... [ABSTRACT FROM AUTHOR]

The actinide pnictides comprise a very interesting group of magnetic materials. Their electronic structures have been studied on a number of occasions in recent years in order to understand the interactions that give rise to their unusual properties. Photoemission techniques are capable of providing information regarding the binding energy of the 5f electron band, as well as dispersion and hybridization with the conduction band, and therefore are an especially valuable tool for investigation of such systems. USb[sub2] is an antiferromagnet below 200 K with a tetragonal layered Cu[sub2]Sb-type structure. PuSb[sub2] has a more complicated orthorhombic SmSb[sub2]-type of structure. The magnetic properties of PuSb[sub2] have not been thoroughly studied up to now, but some preliminary susceptibility study and our photoemission results indicate that PuSb[sub2] orders magnetically at low temperature. We have studied single-crystal USb[sub2] by angle-resolved photoemission with synchrotron radiation in the photon energy range of 14-110 eV at the SRC in Wisconsin. The overall energy resolution for the lowest photon energy range was 24 meV, and the momentum resolution was 0.09 Å[sup-1]. The USb[sub2] samples were cleaved under ultrahigh vacuum conditions, and a smooth and flat surface was obtained for angle-resolved photoemission studies. [ABSTRACT FROM AUTHOR]