Assessment of resonance ionization mass spectrometry for analytical chemistry and spectroscopy (open access)

Assessment of resonance ionization mass spectrometry for analytical chemistry and spectroscopy

Resonance ionization mass spectrometry (RIMS) is a natural outgrowth of RIS. The result of an RIS process is an ion pair. The electron can be used to detect the process, and single atom detection has been demonstrated by this method. The cation resulting from the RIS process actually carries more easily accessible and useful information (i.e. the mass of the ion). RIMS is useful in mass analysis. The development of RIMS has proceeded along several different directions, using CW or pulsed lasers, narrow or wide band laser energies, different kinds of sample generation, and different kinds of mass separations. RIMS in various forms can be used to obtain either element or isotope selectivity. Even though the RIMS technique has developed along several lines, several things are common to all approaches. Ultimately RIMS requires gaseous, free, atoms. RIMS makes use of the photoionization of these atoms by absorption of photons through allowed transitions involving real energy levels. The ion once formed is detected by standard mass spectrometric techniques.
Date: April 20, 1984
Creator: Young, J. P.; Donohue, D. L. & Smith, D. H.
Object Type: Article
System: The UNT Digital Library
Use of induction linacs with nonlinear magnetic drive as high average power accelerators (open access)

Use of induction linacs with nonlinear magnetic drive as high average power accelerators

The marriage of induction linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 Mev/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator is under construction at Lawrence Livermore National Laboratory (LLNL) to allow us to demonstrate some of these concepts. Progress on this project is reported here.
Date: August 20, 1984
Creator: Birx, D. L.; Cook, E. G.; Hawkins, S. A.; Newton, M. A.; Poor, S. E.; Reginato, L. L. et al.
Object Type: Article
System: The UNT Digital Library
Probabilistic analyses of failure in reactor coolant piping. [Double-ended guillotine break] (open access)

Probabilistic analyses of failure in reactor coolant piping. [Double-ended guillotine break]

LLNL is performing probabilistic reliability analyses of PWR and BWR reactor coolant piping for the NRC Office of Nuclear Regulatory Research. Specifically, LLNL is estimating the probability of a double-ended guillotine break (DEGB) in the reactor coolant loop piping in PWR plants, and in the main stream, feedwater, and recirculation piping of BWR plants. In estimating the probability of DEGB, LLNL considers two causes of pipe break: pipe fracture due to the growth of cracks at welded joints (direct DEGB), and pipe rupture indirectly caused by the seismically-induced failure of critical supports or equipment (indirect DEGB).
Date: July 20, 1984
Creator: Holman, G.S.
Object Type: Article
System: The UNT Digital Library
Choice of Tevatron tune with matched low-. beta. insertions (open access)

Choice of Tevatron tune with matched low-. beta. insertions

The Tevatron lattice, following closely the Main Ring lattice, is made up of approximately 90 FODO cells with six straight sections equally spaced. The straight sections are identical (neglecting the special high-..beta.. straight section used for resonant extraction) providing six-fold symmetry. Each straight section is comprised mainly of a pair of doublets, one at each end, in an antisymmetric configuration. The ..beta..-functions are matched to the building block cells but the dispersion function is not. The ..beta..-function matching implies that the structure is not sensitive to the tune of the sextant (i.e., structure resonances); however, the dispersion mismatch excites off-momentum dipole resonances and the dispersion structure of the ring is therefore sensitive to sextant tunes near an integer. The introduction of low-..beta.. insertions can be accomplished by replacing a standard insertion (expanded somewhat from the doublet pair straight section) with a low-..beta.. insertion. By matching the ends of the replacement units with respect to ..beta..-functions and dispersion function, the full lattice is made insensitive to linear structure resonances. Procedures are described here for introducing into the idealized Tevatron lattice considered here a single matched low-..beta.. insertion at BO, and two matched low-..beta.. insertions at BO and DO. The main consequence …
Date: June 20, 1984
Creator: Month, M.
Object Type: Report
System: The UNT Digital Library
Microstability theory for distributions separable in energy and pitch angle (open access)

Microstability theory for distributions separable in energy and pitch angle

Distribution functions that are separable in energy and pitch angle allow analytical calculation of one or two velocity-space integrals that appear in the linear theory of certain microinstabilities.
Date: March 20, 1984
Creator: Smith, G. R.
Object Type: Article
System: The UNT Digital Library
Time-resolved studies of ultrarapid solidification of highly undercooled molten silicon formed by pulsed laser irradiation (open access)

Time-resolved studies of ultrarapid solidification of highly undercooled molten silicon formed by pulsed laser irradiation

This paper reports new results of nanosecond-resolution time-resolved optical reflectivity measurements, during pulsed excimer (KrF, 248 nm) laser irradiation of Si-implanted amorphous (a) silicon layers, which, together with model calculations and post-irradiation TEM measurements, have allowed us to study both the transformation of a-Si to a highly undercooled liquid (l) phase and the subsequent ultrarapid solidification process.
Date: July 20, 1984
Creator: Lowndes, D. H.; Jellison, G. E., Jr.; Wood, R. F. & Carpenter, R.
Object Type: Article
System: The UNT Digital Library
Modern solid state laser materials (open access)

Modern solid state laser materials

This document contains visual aids used in an invited talk entitled Modern Solid State Laser Materials, presented at the Conference on Lasers and Electro-Optics (CLEO) held in Anaheim, California, on June 20, 1984. Interest at LLNL in solid state lasers focuses on evaluating the potential of solid state laser media for high average power applications, including inertial fusion power production. This talk identifies the relevant bulk material parameters characterizing average power capacity and uses chromium and neodymium co-doped gadolinium scandium gallium garnet (Nd:Cr:GSGG) as an example of a laser material with improved laser properties relative to Nd:YAG (plausible large-scale growth, more efficient spectral coupling to xenon flashlamp radiation, reduced stimulated emission cross section, adequate thermal shock and optical damage threshold parameters, etc.). Recently measured spectroscopic, kinetic, and thermo-mechanical properties of Nd:Cr:GSGG are given.
Date: June 20, 1984
Creator: Krupke, W. F.
Object Type: Report
System: The UNT Digital Library
Comparison of three ICF reactor designs (open access)

Comparison of three ICF reactor designs

Three concepts for inertial confinement fusion (ICF) reactors are described and compared with each other, and with magnetic fusion and fission reactors on the basis of environmental impact, safety and efficiency. The critical technical developments of each concept are described. The three concepts represent alternative development paths for inertial fusion.
Date: September 20, 1984
Creator: Hogan, W.J.
Object Type: Article
System: The UNT Digital Library
Facile reaction/extraction of coal with supercritical fluids. Quarterly technical progress report, January 1-March 31, 1984 (open access)

Facile reaction/extraction of coal with supercritical fluids. Quarterly technical progress report, January 1-March 31, 1984

Arylmethyl phenyl ethers undergo competing reactions when treated with Lewis acids in benzene solvent. Apparently, benzene is insufficiently reactive to compete with intramolecular (intrapolymer) nucleophiles and, consequently, no increase in solubility accompanies the cleavages of ether links upon addition of benzene. When better nucleophiles, naphthalene and phenanthene, are provided, carbonium ions generated from ether cleavages are capped and the product is lower in molecular weight and more soluble. It is worth noting that the naphthalene (k/sub rel/ = 300) is nearly as good a trap as the phenol (k/sub rel/ = 450). Since hydroxylic solvents will level the acid strength of BF/sub 3/ to that of ROBF/sub 3//sup -/H/sup +/ and hydrocarbons would not, the acid-catalyzed bond cleavages necessary for unlinking coal may in fact be faster in BF/sub 3/-arene than in BF/sub 3/-phenol. While we have not yet extended these results to coals, we believe that the combination of a relatively mild Lewis acid catalyst, BF/sub 3/, with a good carbonium ion trap, naphthalene, will allow selective cleavage and capping of aryl alkyl ether bonds. 3 references, 2 figures, 3 tables.
Date: April 20, 1984
Creator: Venier, C. G. & Squires, T. G.
Object Type: Report
System: The UNT Digital Library
Simulation program for central helium liquefier (open access)

Simulation program for central helium liquefier

The computer program described here analyzes the performance of Fermilab Central Helium Liquefier (CHL) and predicts the values of the plant thermodynamic variables at all process points in the plant. To simulate CHL, this program is modified from the prototype program which was developed by Hitachi Ltd. a couple of years ago. This program takes care of only the steady state simulation and takes account of the change of the turbine efficiency, the pressure drops and the UA values of the heat exchangers. How to use the program is shown.
Date: February 20, 1984
Creator: Kawamura, S.
Object Type: Report
System: The UNT Digital Library
Operating procedures: Fusion Experiments Analysis Facility (open access)

Operating procedures: Fusion Experiments Analysis Facility

The Fusion Experiments Analysis Facility (FEAF) is a computer facility based on a DEC VAX 11/780 computer. It became operational in late 1982. At that time two manuals were written to aid users and staff in their interactions with the facility. This manual is designed as a reference to assist the FEAF staff in carrying out their responsibilities. It is meant to supplement equipment and software manuals supplied by the vendors. Also this manual provides the FEAF staff with a set of consistent, written guidelines for the daily operation of the facility.
Date: March 20, 1984
Creator: Lerche, R. A. & Carey, R. W.
Object Type: Report
System: The UNT Digital Library
Automatic beam centering at the SSC interaction regions (open access)

Automatic beam centering at the SSC interaction regions

In the SSC interaction regions, the two colliding beams, each only a few microns in size, will have to be centered and maintained in good alignment over many hours, in order to provide the maximum possible luminosity and to minimize off-center beam-beam focussing effects. It is unlikely that sufficiently good alignment can be achieved without some kind of active feedback system, based on the beam-beam interaction rate. This memo describes such a system. In the proposed scheme, one of the beams is moved continuously and in a circular fashion about its mean transverse position. The radius of this motion is approximately 0.01 of the rms beam size at the interaction point. The motion is achieved with two sets of crossed high frequency dipole magnets, one on each side of the interaction region, suitably phased. As a consequence of this motion, the beam-beam interaction rate is modulated in synchronism with the beam motion when the beams are not centered on one another. The amplitude and phase of this modulation yields information on the magnitude and direction of the misalignment between the beams, allowing continuous display and automatic correction of any misalignment.
Date: March 20, 1984
Creator: Joestlein, H.
Object Type: Report
System: The UNT Digital Library
MOD silver metallization for photovoltaics. Quarterly technical report, December 1, 1983-February 29, 1984. [Metallo-organic decomposition] (open access)

MOD silver metallization for photovoltaics. Quarterly technical report, December 1, 1983-February 29, 1984. [Metallo-organic decomposition]

It was determined that pyrolysis products can produce dark surface films on MOD silver conductors. Improving the purity of all ink ingredients helped this problem. It was established that the existence and nature of the surface film is influenced by the rate of air flow during firing and by the heating rate in the 70 to 225/sup 0/C range, but these processing parameters have not as yet been optimized. Low temperature solvent removal was determined to be of prime importance in obtaining good adhesion between the MOD films and the substrate. For inks developed to date, 15 to 30 minutes at 60 to 70/sup 0/C was required. It was also determined that the adhesion is influenced by the air flow rate during firing, the heating rate in the 100 to 250/sup 0/C range, and the maximum firing temperature. Results during the first 3 months of effort on this project have demonstrated that it is essential to use generic compounds, and that the compounds must be prepared from high purity raw materials. It was also established that the quality and properties of the MOD silver films are intimately dependent on the time-temperature processing. All of the results obtained to date still …
Date: March 20, 1984
Creator: Vest, G. M. & Vest, R. W.
Object Type: Report
System: The UNT Digital Library
Energy Demand and Fuel Supply in Developing Countries Brazil,Korea and the Philippines (open access)

Energy Demand and Fuel Supply in Developing Countries Brazil,Korea and the Philippines

None
Date: May 20, 1984
Creator: Sathaye, Jayant A.
Object Type: Report
System: The UNT Digital Library
The Double-Tuned Coupling Circuit Theory and Design Criteria (open access)

The Double-Tuned Coupling Circuit Theory and Design Criteria

None
Date: August 20, 1984
Creator: M., Puglisi
Object Type: Report
System: The UNT Digital Library
Parameters Of The RF System For The “Weak-Focusing” Lattices (open access)

Parameters Of The RF System For The “Weak-Focusing” Lattices

None
Date: January 20, 1984
Creator: H., Hahn
Object Type: Report
System: The UNT Digital Library
Fixed-fugacity option for the EQ6 geochemical reaction path code (open access)

Fixed-fugacity option for the EQ6 geochemical reaction path code

EQ3/6 is a software package used to model aqueous geochemical systems. The EQ6 code allows reaction paths of dynamic systems to be calculated. This report describes a new option for the EQ6 computer program that permits the fugacity of any gas in the EQ6 data base to be set to a fixed value. This capability permits simulation of the effect of rapid chemical exchange with a large external gas reservoir by allowing the user to fix the fugacities of selected gas species. Geochemical environments such as groundwater systems open to the atmosphere (e.g., the unsaturated zone), natural aqueous systems that form closed systems at depth, and experimental systems that use controlled atmospheres can be modeled. Two of the principal geochemical weathering agents, CO{sub 2} and O{sub 2}, are the most likely gas species for which this type of exchange may be important. An example of the effect of constant CO{sub 2} fugacity on both open and closed systems is shown for the case of albite dissolution (NaAlSi{sub 3}O{sub 8}) in distilled water. This example demonstrates that the effects of imposed fugacities on geochemical systems can be considerable. This computer code is used in the Nevada Nuclear Waste Storage Investigations Project. …
Date: December 20, 1984
Creator: Delany, J. M. & Wolery, T. J.
Object Type: Report
System: The UNT Digital Library