The 6'' long final focus beam position monitors (short FF BPM's are longer, thus deliver more signal after a 15 nanosecond filter, than either the Linac or Arc monitors. The purpose of this note is to compare the resolution of the Arc vs Linac electronics when applied to a short FF 2'' diameter BPM. A method of calibrating the Arc modules is also tested and briefly discussed. The range of each DAC setting to minimize digitization error is also calculated.

Three lectures comprise the report. The lecture, Atomic Structure, is primarily theoretical and covers four topics: (1) Non-relativistic one-electron atom, (2) Relativistic one-electron atom, (3) Non-relativistic many-electron atom, and (4) Relativistic many-electron atom. The lecture, Radiative and Collisional Transitions, considers the problem of transitions between atomic states caused by interactions with radiation or other particles. The lecture, Ionization Balance: Spectral Line Shapes, discusses collisional and radiative transitions when ionization and recombination processes are included. 24 figs., 11 tabs.

Recent work on s-process nucleosynthesis has focused attention on the investigation of capture cross sections for nuclei in the mass region near the N = 50 closed neutron shell. Of special astrophysical interest are (i) the analysis of the s-process branching through /sup 85/Kr as a monitor of stellar neutron density and temperature and (ii) the investigation of the possible chronometric pair /sup 87/Rb-/sup 87/Sr as an independent measure of the age of the galaxy. For both problems the capture cross sections of the two pure s-process nuclei /sup 86/Sr and /sup 87/Sr have to be known to an accuracy of 5% or better. The current investigation of the neutron capture cross sections for /sup 86/Sr and /sup 87/Sr was undertaken to extend recent measurements by Walter and Beer to energies below 3.5 keV, where strong resonances are known to exist, and to explore the discrepancy in the results of the Maxwellian averaged capture cross section of /sup 87/Sr at kT = 30 keV as reported by previous investigators. 9 refs., 1 fig.

A companion star within 0.8 pc of the Sun has been postulated to explain a possible 26 Myr periodicity in mass extinctions of species on the Earth. Such a star would already be catalogued in the Yale Bright Star catalogue unless it is fainter than m/sub nu/ = 6.5; this limits the possible stellar types for an unseen companion to red dwarfs, brown dwarfs, or compact objects. Red dwarfs account for about 75% of these possible stars. We describe here the design and development of an astrometric search for a nearby red dwarf companion with a six-month peak-to-peak parallax of greater than or equal to2.5 arcseconds. We are measuring the parallax of 2770 candidate faint red stars selected from the Dearborn Observatory catalogue. An automated 30-inch telescope and CCD camera system collect digitized images of the candidate stars, along with a 13' x 16' surrounding field of background stars. Second-epoch images, taken a few months later, are registered to the first epoch images using the background stars as fiducials. An apparent motion, m/sub a/, of the candidate stars is found to a precision of sigma/sub m//sub a/ approx. = 0.08 pixel approx. = 0.2 arcseconds for fields with N/sub fiducial/ …

Accelerator mass spectrometry in tandem Van de Graaff accelerators has proven successful for radioisotope dating small samples. We are developing a 20 cm diameter 30 to 40 keV cyclotron dedicated to high-sensitivity radioisotope dating, initially for /sup 14/C. At this energy, range and dE/dx methods of particle identification are impossible. Thus arises the difficult problem of reliably detecting 30 to 40 keV /sup 14/C at 10/sup -2/ counts/sec in the high background environment of the cyclotron, where lower energy ions, electrons, and photons bombard the detector at much higher rates. We have developed and tested an inexpensive, generally useful ion detector that allows dark-count rates below 10/sup -4/ counts/sec and excellent background suppression. With the cyclotron tuned near the /sup 13/CH background peak, to the frequency for /sup 14/C, the detector suppresses the background to 6 x 10/sup -4/ counts/sec. For each /sup 14/C ion the detectors grazing-incidence Al/sub 2/O/sub 3/ conversion dynode emits about 20 secondary electrons, which are independently multiplied in separate pores of a microchannel plate. The output signal is proportional to the number of secondary electrons, allowing pulse-height discrimination of background. We have successfully tested the detector with positive /sup 12/C, /sup 23/Na, /sup 39/K, /sup …

This report describes the design and construction of five spoiler magnets installed in the secondary beamline to the Meson West Experimental Hall. Tests have been performed to measure the magnetic field in the steel as a function of the excitation current. B versus I curves for each spoiler are included. The leakage field in the beam pipe through the spoiler steel was too high. Magnetic shield and reduced excitation are used to lower this leakage field to acceptable levels.

The Solar Energy Research Institute (SERI) is conducting research on the development of microalgae biomass systems for the production of liquid fuels. Particularly appealing at this time, is the idea of using indigenous resources of the Southwest for large-scale production of microalgae.

Nuclear-explosive prompt diagnostics techniques and equipment are surveyed. These techniques and equipment have been developed to answer nuclear-explosive performance questions. The techniques and equipment must be selective in radiation sensitivity, linear in calibration, fast, insensitive to strong signals, wide in dynamic range, and reliable. Diagnostic techniques and equipment measure neutron, gamma-ray, and x-ray emissions, as well as aid in the determination of the physical location of the production of radiation through imaging. The high cost of nuclear experiments will continue to encourage the development of sophisticated techniques to gain as much information as possible from each experiment.

This report provides a series of assessments regarding China's strategy and objectives for computer development. It examines the specific role played by acquisition of foreign computers and related know-how by PRC.

Weekly report of the Texas Crop and Livestock Reporting Service on broiler chick numbers in Texas and compared with other states. It includes compiled statistics across six consecutive weeks, from the week ending May 17 to the week ending June 21, during 1985 and 1986 for broiler eggs set, chicks hatched, and chicks placed.

This report addresses two broad aspects of the behaviors of hydrodynamic flows, resulting from laser heated, exploding foils. In Part I, various aspects of the similarity solutions are considered, whereas in Part II the stability of the flows at early times are examined, before the similarity solutions are established. 5 refs., 3 figs.