Feature Articles

Imaging with laser scanners

Electronic image analysis and synthesis entails the sampling of a real or computer-generated image to derive an "equivalent electrical signal, and after logical manipulation, reconstructing the image for visual interpretation. The input process is called scanning (or digitizing, if digitized) and the output one, recording, printing, or display.

by Leo Beiser
Exploratory research in reflectance and fluorescence standards at the National Bureau of Standards

Researchers in the Center for Radiation Research and the Center for Analytical Chemistry at the National Bureau of Standards (NBS) are responsible for the development and calibration of a number of standards for checking the performance of spectrophotometers, spectrofluorimeters, and related analytical instrumentation. Many of these standards are available as Standard Reference Materials

by Victor R. Weidner, Jack J. Hsia, and Kenneth L. Eckerle
Resonance ionization mass spectrometry for spectra of rare isotopes

Resonance ionization mass spectrometry (RIMS) is becoming a useful tool for isotopic analysis, especially in cases when isobaric (same-mass) interferences from other elements can perturb results. In RIMS, one or more dye lasers are tuned to match atomic transitions (resonances) of atoms of the element of interest in the sample chamber of a mass spectrometer. This causes stepwise excitation of the atoms through the resonant energy levels to the ionization continuum, resulting in a positive ion and an electron. The positive ion is then mass analyzed by the mass spectrometer.

by R. Engleman Jr., R.A. Keller, and C.M. Miller
Optics and optical instruments

We continue this month describing the work of the various subcommittees of ISO/TC172-Optics and optical instruments.

by Robert E. Parks