Spectroscopic study of coal structure and reactivity (open access)

Spectroscopic study of coal structure and reactivity

Work done during this period (December 15, 1989 to March 14, 1990) covered two of the three primary areas of study of this project. The first involved the continuing development a of step-scanning interferometer for the photoacoustic depth-profiling of materials whose composition varies in the spatial region between 5 and 50 {mu}m from its surface. The second covered the initial construction of an on-line interface between a supercritical fluid chromatograph (SFC) and a Fourier transform infrared (FT-IR) spectrometer for monitoring the composition of coal extracts. 5 refs., 8 figs.
Date: September 7, 1990
Creator: Rabenstein, D.L.
Object Type: Report
System: The UNT Digital Library
Inner-shell ionization of lithium-like chromium ions (open access)

Inner-shell ionization of lithium-like chromium ions

We have used high-resolution x-ray spectroscopy to investigate inner-shell ionization of Cr{sup 21+} ions by electron impact using the Electron Beam Ion Trap at Lawrence Livermore Laboratory. Our measurements indicate that inner-shell ionization enhances the intensity of the radiative transition 1s2s {sup 3}S{sub 1}{yields}1s{sup 2}{sup 1}S{sub 0}. 7 refs., 4 figs., 1 tab.
Date: September 7, 1990
Creator: Vogel, D. A.; Beiersdorfer, P.; Marrs, R. E.; Wong, K. L. & Zasadzinski, R.
Object Type: Article
System: The UNT Digital Library
Spectroscopic study of coal structure and reactivity (open access)

Spectroscopic study of coal structure and reactivity

The aim of this project is to perform quantitative analysis of the Fourier transform infrared (FT-IR) spectra of coals and coal extracts. The major difficulty encountered in the analysis of the FT-IR spectra of coals is the complexity of the bands, which consist of many closely overlapped peaks. Two techniques that are commonly used for the quantitative analysis of complex FT-IR spectra are deconvolution and curve-fitting. Deconvolution is a mathematical technique that narrows the speaks in a spectrum, thereby improving the effective resolution. Curve-fitting optimizes a set of ban parameters, using a least squares criterion, to simulate the true spectrum. We have recently completed work on optimizing the combination of these two techniques with the aim of applying this to the spectra of coals and coal extracts. Two types of deconvolution were investigated in this context: Fourier self-deconvolution (FSD) and maximum likelihood restoration (MLR). It was concluded that for noisy spectra MLR gave superior results. 3 refs., 7 figs.
Date: September 7, 1990
Creator: Rabenstein, D.L.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 15, Number 68, Pages 5079-5153, September 7, 1990 (open access)

Texas Register, Volume 15, Number 68, Pages 5079-5153, September 7, 1990

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: September 7, 1990
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Attorney General Opinion: JM-1217 (open access)

Texas Attorney General Opinion: JM-1217

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, Jim Mattox, regarding a legal question submitted for clarification: Acceptance of bail bonds by peace officers under articles 17.01 and 17.02 of the Texas Code of Criminal Procedure (RQ-2016)
Date: September 7, 1990
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Electron impact ionization cross section measurement of lithium-like barium ions (open access)

Electron impact ionization cross section measurement of lithium-like barium ions

The electron impact ionization cross section of Li-like Ba{sup 53+} has been measured at 22 keV using an electron beam ion trap. The measurement makes use of a novel technique, which is discussed in detail. We find a value somewhat higher than predicted by theory.
Date: September 7, 1990
Creator: Wong, K.; Beiersdorfer, P.; Vogel, D.A.; Marrs, R.E. (Lawrence Livermore National Lab., CA (USA)) & Levine, M. (Lawrence Berkeley Lab., CA (USA))
Object Type: Article
System: The UNT Digital Library
A systematic study of actinide production from the interactions of heavy ions with sup 248 Cm (open access)

A systematic study of actinide production from the interactions of heavy ions with sup 248 Cm

Production cross sections for heavy actinides produced from the interactions of {sup 12}C, {sup 31}P, {sup 40}Ar, and {sup 44}Ca ions with {sup 248}Cm were measured at energies ranging from 0.98 to 1.35 X Coulomb barrier. The recoiling reaction products were collected in copper or gold catcher foils located near the {sup 248}Cm target. Separate fractions of Bk, Cf, Es, Fm, and Md were obtained from a radiochemical separation procedure. For the {sup 12}C system, a He/KCl jet was used to transport the recoiling No activities of interest to a rotating wheel system. The isotopic distributions of the actinide products were found to be essentially symmetric about the maximum with full-widths-at-half-maximum of approximately 2.5 mass units. Isotopic distributions of the {sup 12}C, {sup 31}P, {sup 40}Ar, and {sup 44}Ca systems were found to be very similar to the {sup 40,48}Ca systems studied previously. The maxima of the isotopic distributions generally occurred for those reaction channels which involved the exchange of the fewest number of nucleons between the target and projectile for which the calculated excitation energy was a positive quantity. Additionally, the maxima of the excitation functions occurred at those projectile energies which were consistent with the calculated reaction barriers …
Date: September 7, 1990
Creator: Leyba, J.D.
Object Type: Report
System: The UNT Digital Library
Feed-forward compensation for transient beam loading of the 805 MHz debuncher for the Fermilab linac upgrade (open access)

Feed-forward compensation for transient beam loading of the 805 MHz debuncher for the Fermilab linac upgrade

The expected momentum spread from the 400 MeV upgrade of the Fermilab linac is {plus minus}0.19% growing to about {plus minus}0.25% in 63 m of beam transport to the booster synchrotron. The desired injection value is about {plus minus}0.05%. An 805 MHz (h=1) debuncher is located 47 m downstream of the linac to reduce the momentum spread and the differences in mean energy between bunches. The beam pulse to the booster will vary from about 2--15 {mu}s at average current of 30--50 mA depending on program need. During 15 {mu}s the beam excitation of the debuncher can reach 2.2 MV/m for a three-cell cavity. This gradient is comparable to, but 90{degree} out of phase with, the 3.85 MV/m required to minimize the momentum spread. We choose to use feed-forward compensation to control the cavity field for the entire beam pulse. We discuss some general features of transient beam loading as well as the design and detailed simulation of the compensation scheme.
Date: September 7, 1990
Creator: MacLachlan, J. A.; Mills, F. E. & Owens, T.
Object Type: Article
System: The UNT Digital Library