Neutron time-of-flight detectors (nTOF) used at Sandia's Z-Machine.

Neutron time-of-flight (nTOF) detectors have been used on Sandia National Laboratories' Z-Machine for inertial confinement fusion and magnetized liner fusion experiments to infer physics parameters including the apparent fuel-ion temperature, neutron yield, the magnetic-radius product (BR), and the liner rho-r. Single-paddle, dual-paddle, and co-axial scintillation nTOF detectors are used in axial lines-of-sight (LOS) and LOS that are 12° from the midplane. Detector fabrication, characterization, and calibration are discussed.

Superlinearity, saturation, and the PMT-Tailoring and calibration methodology for prompt radiation detectors.

This work illustrates predominant measureable nonlinearities in photomultiplier tubes (PMTs) and introduces a controllable one called "Superlinearity," signifying both a positive nonlinear response and the ability to extend linear operation by counteracting gain saturation mechanisms - charge depletion, space-charge field limitation, and secondary emission surface effects. Recognizing superlinearity and its effect on the temporal step response leads to a true definition of linearity, free of a small-signal linear assumption. Furthermore, given the prevalent use of glass microchannel-plate (MCP) PMTs in favor of a faster impulse response in spite of a small charge limit, we are motivated to examine their nonlinear amplitude response and deploy tailored gain bias string methods to fully harness the maximum linear gain as is usually done for transmissive metal mesh and reflective metal dynode PMTs.

The neutron imaging diagnostic at NIF (invited).

A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector.

Modeling the National Ignition Facility neutron imaging system.

Numerical modeling of the neutron imaging system for the National Ignition Facility (NIF), forward from calculated target neutron emission to a camera image, will guide both the reduction of data and the future development of the system. Located 28 m from target chamber center, the system can produce two images at different neutron energies by gating on neutron arrival time. The brighter image, using neutrons near 14 MeV, reflects the size and symmetry of the implosion "hot spot.

One-dimensional neutron imager for the Sandia Z facility.

A multiinstitution collaboration is developing a neutron imaging system for the Sandia Z facility. The initial system design is for slit aperture imaging system capable of obtaining a one-dimensional image of a 2.45 MeV source producing 5x10(12) neutrons with a resolution of 320 microm along the axial dimension of the plasma, but the design being developed can be modified for two-dimensional imaging and imaging of DT neutrons with other resolutions.

Biomaterials for drug delivery systems.

Drug delivery systems have unusual materials requirements which derive mainly from their therapeutic role: to administer drugs over prolonged periods of time at rates that are independent of patient-to-patient variables. The chemical nature of the surfaces of such devices may stimulate biorejection processes which can be enhanced or suppressed by the simultaneous presence of the drug that is being administered. Selection of materials for such systems is further complicated by the need for compatibility with the drug contained within the system.

It is appropriate to create new pharmaceutical products within developing countries.

Arguments are presented for utilizing local product development as an appropriate way to solve many of the current medical problems of the Third World. Guidelines for selecting problems amenable to this approach are provided, and the risks attendant on such an activity outlined. It is suggested that organizations such as the World Health Organization can encourage this approach by helping to provide training in product development and by providing consulting services for organizations in the developing world.

Continuous intravenous arabinosyl cytosine infusions delivered by a new portable infusion system.

Eighty-six patients with acute leukemia were given 116 continuous intravenous arabinosyl cytosine (Ara-C) infusions (for 24 to 432 hours) with a new portable infusion device. The infusor is powered by interchangeable elastomeric 25 ml balloon reservoirs loaded from standard syringes. The reservoir contents are discharged at nearly constant pressure through an adjustable resistance element, thereby providing flow rates from 0.

Correction of the atrophic alveolar ridge by interpositional bone grafting: a progress report.

A retrospective study of postoperative stability and osseous changes was made on nine patients with maxillary or mandibular atrophy who were treated with interpositional bone grafting techniques. There was minimal discernible positional change or resorption of the portion of the maxilla or mandible that was moved by interpositional grafting procedures. Sequential radiographs and cephalometric tracings showed early consolidation of the grafted bone, minimal resorption of the respositioned osseous segments, and a small decrease of alveolar ridge height during an average potsoperative follow-up period of seven months.

Influence of Selected Processing Variables on Holographic Film Parameters: Kodak SO-243.

The influence of selected processing variables on photographic film parameters of importance in optical data processing and holographic systems has been measured. Details of the tests chosen and their importance are given. Results are presented on amplitude transmittance, diffraction efficiency, and spatial frequency response characteristics for Kodak SO-243.

Cineholomicroscopy of small animal microcirculation.

A holomicrographic system capable of recording the dynamic microscopic events occurring in a living tissue has been developed. This paper discusses the system parameters, the basic configuration, and initial test results. The reconstructed real image from the hologram can be studied with a conventional microscope.