Office of Electronic Commerce in Scientific and Engineering Data

Technical Highlights

• Physics Laboratory Information on the WWW We began providing information to the public in June 1994. By the end of fiscal year 1998, we were supplying 270,000 PL documents each month to users outside of NIST (fully half from our databases). The rate of use continues to increase rapidly.

  A wide array of information is provided by PL on the WWW. It ranges from staff and organization information to PL technical activities, publication lists, research facilities, news items, physical reference data, and bibliographic information about physical reference data. New information is added regularly. We develop programs to provide this information and innovations to overcome the limitations of current browsers.

  For Internet users who want to access the PL WWW server, the Internet URL for the PL web server is physics.nist.gov/ .
• Photon Cross Section Databases Developed for PL Web Server. The ECSED office developed a web version of NIST Standard Reference Database 8, XCOM: NIST X-Ray and Gamma-Ray Attenuation Coefficients and Cross Sections Database by M.J. Berger and J.H. Hubbell. It provides information on the scattering and absorption of photons (x-rays, gamma rays, and bremsstrahlung) which is required for many scientific, engineering and medical applications. In addition to elements, results may be obtained for arbitrary user specified-compounds and mixtures.
• Databases of Stopping Powers and Range Tables Developed for the WWW. The ECSED office developed web versions of the NIST ESTAR, PSTAR, and ASTAR databases of the stopping power and range tables of electrons, protons, and alpha particles, respectively, which were originally calculated by M.J. Berger. They provide stopping power and range information in a large number of elements and materials of interest to the medical, space science, and engineering communities.
• Database of Ground Levels and Ionization Energies for the Neutral Atoms Developed for the WWW. A database consisting of a critical compilation of the ionization energies and ground state configurations by W.C. Martin and A. Musgrove has been made available on the WWW. The data for the first 104 elements is presented as a table and comes complete with bibliographic references. The database provides this important information in an easy to access form.
• Wide Range of Databases Developed for WWW Dissemination. This Office develops and makes available over the web a wide range of physical reference databases. In addition to the three mentioned above we provide databases of the Fundamental Physical Constants; Atomic Spectroscopic Information; Spectrum of a Platinum Lamp; Wavenumber Tables for Calibration of Infrared Spectrometers; Frequencies for Interstellar Molecular Microwave Transitions; X-Ray Attenuation and Absorption for Materials of Dosimetric Interest; X-ray Form Factor, Attenuation, and Scattering; Cross Sections for Electron Impact Ionization; Radionuclide Half-Life Measurements Made at NIST; and Bibliographies of Atomic Transition Probabilities, Photon Attenuation Measurements, and Fundamental Constant Determinations.
• The NIST Reference on Constants, Units and Uncertainty Available on the Web. The ECSED Office in collaboration with the Fundamental Constants Data Center made extensive supporting documentation on constants, units and uncertainty available on the WWW. This carefully designed material provides essential support to the many users of the Fundamental Constants Database as well as to the users of the rest of our WWW Physical Reference Data.