Bulletin on Texas State Finance: 1993, Number 1 (open access)

Bulletin on Texas State Finance: 1993, Number 1

Periodic bulletin analyzing issues related to Texas legislation. This issue focuses on property values.
Date: February 22, 1993
Creator: Texas Research League
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Geographos asteroid flyby and autonomous navigation study (open access)

Geographos asteroid flyby and autonomous navigation study

Deep Space Program Science Experiment (DSPSE), also known as Clementine, is a collection of science experiments conducted in near-earth with the goal of demonstrating Strategic Defense Initiative Office (SDIO) developed technologies. The 785 lb (fully fueled) spacecraft will be launched into low Earth orbit in February 1994 together with a Star 37 solid kick motor and interstage. After orbit circulation using Clementine`s 110 lb Delta-V thruster, the Star 37 will execute a trans-lunar injection burn that will send the spacecraft toward lunar obit. The 110-lb will then be used in a sequence of burns to insert Clementine into a trimmed, polar orbit around the moon. After a two month moon mapping mission, Clementine will execute burns to leave lunar orbit, sling-shot around Earth, and flyby the moon on a 9.4 million km journey toward the asteroid Geographos. After about three months in transit, Clementine will attempt a flyby with a closest point of approach of 100 km from the asteroid on August 31, 1994. During its approach to Geographos, Clementine will be tracked by the Deep Space Network (DSN) and receive guidance updates. The last update and correction burn will occur about one day out of the flyby. Multiple experiments …
Date: February 22, 1993
Creator: Ng, L. C.; Pines, D. J.; Patz, B. J. & Perron, D. C.
Object Type: Article
System: The UNT Digital Library
Longitudinal beam dynamics for heavy ion fusion using WARPrz (open access)

Longitudinal beam dynamics for heavy ion fusion using WARPrz

WARPrz is a 2.5 dimensional, cylindrically symmetric, electrostatic, particle-in-cell code. It is part of the WARP family of codes which has been developed to study heavy ion fusion driver issues. WARPrz is being used to study the longitudinal dynamics of heavy ion beams including a longitudinal instability that is driven by the impedance of the LINAC accelerating modules. This instability is of concern because it can enhance longitudinal momentum spread; chromatic abhoration in the lens system restricts the amount of momentum spread allowed in the beam in the final focusing system. The impedance of the modules is modeled by a continuum of resistors and capacitors in parallel in WARPrz. We discuss simulations of this instability including the effect of finite temperature and reflection of perturbations off the beam ends. We also discuss intermittency of axial confining fields (``ears`` fields) as a seed for this instability.
Date: February 22, 1993
Creator: Callahan, D. A.; Langdon, A. B.; Friedman, A. & Haber, I.
Object Type: Article
System: The UNT Digital Library
Model building, control and optimization of large scale systems (open access)

Model building, control and optimization of large scale systems

This report covers the research progress made during the calendar year 1992. The new results obtained during this period are described, keyed to the references listed on the last two pages of this report.
Date: February 22, 1993
Creator: Basar, T.
Object Type: Report
System: The UNT Digital Library
Model building, control and optimization of large scale systems. Progress report, January 1992--January 1993 (open access)

Model building, control and optimization of large scale systems. Progress report, January 1992--January 1993

This report covers the research progress made during the calendar year 1992. The new results obtained during this period are described, keyed to the references listed on the last two pages of this report.
Date: February 22, 1993
Creator: Basar, T.
Object Type: Report
System: The UNT Digital Library
Overview of WARP, a particle code for Heavy Ion Fusion (open access)

Overview of WARP, a particle code for Heavy Ion Fusion

The beams in a Heavy Ion beam driven inertial Fusion (HIF) accelerator must be focused onto small spots at the fusion target, and so preservation of beam quality is crucial. The nonlinear self-fields of these space-charge-dominated beams can lead to emittance growth; thus a self-consistent field description is necessary. We have developed a multi-dimensional discrete-particle simulation code, WARP, and are using it to study the behavior of HIF beams. The code`s 3d package combines features of an accelerator code and a particle-in-cell plasma simulation, and can efficiently track beams through many lattice elements and around bends. We have used the code to understand the physics of aggressive drift-compression in the MBE-4 experiment at Lawrence Berkeley Laboratory (LBL). We have applied it to LBL`s planned ILSE experiments, to various ``recirculator`` configurations, and to the study of equilibria and equilibration processes. Applications of the 3d package to ESQ injectors, and of the r, z package to longitudinal stability in driver beams, are discussed in related papers.
Date: February 22, 1993
Creator: Friedman, A.; Grote, D. P.; Callahan, D. A.; Langdon, A. B. & Haber, I.
Object Type: Article
System: The UNT Digital Library
A Performance Review of Austin Independent School District (ISD), February 1993 (open access)

A Performance Review of Austin Independent School District (ISD), February 1993

A performance review of Austin Independent School District (ISD) examining their use of funds in different areas of the school system.
Date: February 22, 1993
Creator: Texas. Comptroller's Office.
Object Type: Report
System: The Portal to Texas History
PIC space-charge emission with finite {Delta}t and {Delta}z (open access)

PIC space-charge emission with finite {Delta}t and {Delta}z

A new algorithm for space charge emission has been developed to provide the correct (to a few percent) Child-Langmuir steady-state current limits as the number of mesh points in the voltage gap drops to O(10). Further, the transient behavior of such flows compares well with idealized, analytic cases, lending confidence as we extend these algorithms into full RZ geometry with curved emitting surfaces to investigate transient characteristics of realistic injector designs.
Date: February 22, 1993
Creator: Hewett, D. W. & Chen, Yu-Jiuan
Object Type: Article
System: The UNT Digital Library
Precision of source response inside dimpled HAD brass tubes (open access)

Precision of source response inside dimpled HAD brass tubes

We have measured the variation in response of the {sup 137}CS source as positioned in 10 samples of the brass source tubes, dimpled at {plus_minus}5 cm from the center of a scintillator tile. We find an RMS in the signals of 2.5%.
Date: February 22, 1993
Creator: Jankowski, D. J. & Stanek, R.
Object Type: Report
System: The UNT Digital Library
Precision of source response inside dimpled HAD brass tubes (open access)

Precision of source response inside dimpled HAD brass tubes

We have measured the variation in response of the [sup 137]CS source as positioned in 10 samples of the brass source tubes, dimpled at [plus minus]5 cm from the center of a scintillator tile. We find an RMS in the signals of 2.5%.
Date: February 22, 1993
Creator: Jankowski, D. J. & Stanek, R.
Object Type: Report
System: The UNT Digital Library
Texas Disease Prevention News, Volume 53, Number 4, February 1993 (open access)

Texas Disease Prevention News, Volume 53, Number 4, February 1993

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.
Date: February 22, 1993
Creator: Texas. Department of Health.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Pecan Pest Management Newsletter, Volume 93, Number 1, February 1993 (open access)

Texas Pecan Pest Management Newsletter, Volume 93, Number 1, February 1993

Newsletter focusing on pecan disease and pest control in Texas, including prevention, identification, treatment, and educational opportunities.
Date: February 22, 1993
Creator: Texas Agricultural Extension Service
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History