High-order harmonic generation provides a new method for generating coherent, XUV radiation. These harmonics are characterized by a rapid, pertubative drop at low orders, followed by a broad plateau extending to photon energies of 150 eV in the lighter, rare gas atoms. An experimentally observed limit coincides with the theoretical limit for harmonic generation in neutral atoms given by the expression E{sub c}(eV)=IP(0)+3U{sub p}(I), where E{sub c} is the energy cutoff of the harmonic plateau, IP(O) is the field-free ionization potential and U{sub p} is the electron quiver energy at the maximum intensity, I seen by the atom. As part of an effort to develop this technique into a general purpose XUV source, extensive work to understand the phase-matching between the harmonic and driving fields, and the resulting effect on the conversion efficiency, angular distribution and spectral brightness has been undertaken at several. Though, certain aspects of the harmonically generated radiation such as the polarization, relative strength of a given harmonic, and the plateau extent, are defined by the single atom-field interaction. Specifically, the single-atom harmonic spectrum is determined primarily by the interaction of a driven, quasi-free electron with the atomic potential. Using two, independent fields one can affect the …

A long term goal of soft x-ray imaging has been to make ultrahigh resolution images of unstained, unprepared, wet, live biological microstructures in physiological normal environments. This is now being accomplished with features as small as 300 {Angstrom} being observed in two dimensional x-ray images. While this achievement is remarkable, most complex biological structures are three dimensional in nature and will require three dimensional images on the few hundred Angstrom scale for the structure-function studies required by modern biology. We have been endeavoring to achieve this three dimensional capability with soft x-ray techniques.

To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r[sub 0] and power index [gamma] of the 2-point correlation, [anti [Xi]][sub 2] = (r[sub 0]/r)[sup [gamma]], and as the hierarchical amplitudes of the 3- and 4-point functions, S[sub 3] = [anti [Xi]][sub 3]/[anti [Xi]][sub 2][sup 2] and S[sub 4] = [anti [Xi]]/[anti [Xi]][sub 2][sup 3]. We find a characteristic distortion for [anti [Xi]][sub 2]: The slope [gamma] is flatter and the correlation length is larger in redshift space than in real space; that is, redshift distortions move'' correlations from small to large scales. At the largest scales, extra power in the redshift distribution is compatible with [Omega][sup 4/7]/b [approx] 1; we find 0.53 [plus minus] 0.15, 1.10 [plus minus] 0.16 and 0.84 [plus minus] 0.45 for the CfA, SSRS and IRAS catalogs. Higher order correlations [anti [Xi]][sub 3] and [anti [Xi]][sub 4] suffer similar redshift distortions, but in such a way that, within the accuracy of our analysis, the normalized amplitudes …

To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r{sub 0} and power index {gamma} of the 2-point correlation, {anti {Xi}}{sub 2} = (r{sub 0}/r){sup {gamma}}, and as the hierarchical amplitudes of the 3- and 4-point functions, S{sub 3} = {anti {Xi}}{sub 3}/{anti {Xi}}{sub 2}{sup 2} and S{sub 4} = {anti {Xi}}/{anti {Xi}}{sub 2}{sup 3}. We find a characteristic distortion for {anti {Xi}}{sub 2}: The slope {gamma} is flatter and the correlation length is larger in redshift space than in real space; that is, redshift distortions ``move`` correlations from small to large scales. At the largest scales, extra power in the redshift distribution is compatible with {Omega}{sup 4/7}/b {approx} 1; we find 0.53 {plus_minus} 0.15, 1.10 {plus_minus} 0.16 and 0.84 {plus_minus} 0.45 for the CfA, SSRS and IRAS catalogs. Higher order correlations {anti {Xi}}{sub 3} and {anti {Xi}}{sub 4} suffer similar redshift distortions, but in such a way that, within the accuracy of our analysis, the normalized amplitudes S{sub 3} and …

We have used the 2-D PIC code, GYMNOS, to study the transient behaviors in the Heavy Ion Fusion (HIF) injectors. GYMNOS simulations accurately provide the steady state Child-Langmuir current and the beam transient behavior within a planar diode. The simulations of the LBL HIF ESAC injector experiments agree well with the experimental data and EGUN steady state results. Simulations of the nominal HIF injectors have revealed the need to design the accelerating electrodes carefully to control the ion beam current, particularly the ion loss at the end of the bunch as the extraction voltage is reduced.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification; Whether provisions of the City of Greenville regulation of pesticides ordinance are preempted by the Structural Pest Control Act, V.T.C.S. article 135b-6 (RQ-511)

Newsletter focusing on pecan disease and pest control in Texas, including prevention, identification, treatment, and educational opportunities.