Summary describing research projects and other activities undertaken by the U.S. National Bureau of Standards, lists of publications from the year, and a calendar of upcoming events.

From introduction: In this report the following will he discussed: (1) design consideration of the broadband magnetic field sensor, (2) overall design of the magnetic field meter, (3) performance of the meter, (4) calibration and operating procedures, (5) alignment and adjustment procedures, and (6) summary and conclusions.

Abstract: In September 1983, the "8th U. S. - German Seminar of State and Planning on Environmental Specimen Banking" and the "International Review of Environmental Specimen Banking" were held at the National Bureau of Standards. At these meetings the current status of Environmental Specimen Banking Program in the U. S., Federal Republic of Germany (FRG), and other countries was presented and discussed. This publication contains a brief summary of these meetings and separate contributions describing the specimen banking activities in Canada, FRG, Japan, Sweden and the U. S.

Abstract: Selected publications of the National Bureau of Standards technical staff in the field of electricity were first compiled in 1962 as a volume of the NBS Precision Measurement and Calibration Series (Electricity and Electronics, Handbook 77, Volume I); this compilation was extended in 1968 by the compilation of an additional volume in the Precision Measurement and Calibration Series (Electricity-Low Frequency, NBS Special Publication 300, Volume 3). The present volume, a further extension of these earlier compilations of selected publications in the field of electricity, includes 66 more recent papers by NBS authors and 16 abstracts of closely related papers by authors from other organizations. In view of the expansion of measurement technologies used in electricity and electromagnetism it has been necessary to reduce the range of topics for the selection of papers in the new compilation. In this connection an emphasis has been placed upon the realization and maintenance of fundamental electrical units and the related scientific advances, particularly in quantum physics. However, in the interest of completeness, three appendices also provide up-to-date bibliographies of publications by NBS authors in different areas of electromagnetism. (This book is a sequel to NBS Handbook 77-Vol. 1(1961) and NBS SP 300-Vol. 3 …

From introduction: The fabrication of various iris-fed millimeterwave rectangular microstrip patch antennas is described. A model is proposed to describe the iris-fed antenna. Irises ranging in size from 15 percent of the area of the patch to the fully open waveguide are used to couple energy into the antenna. Resonance of the antenna is observed to be insensitive to the size of the iris for irises up to 115 percent of the size of the patch. A study is also made of th? relationship of coupling to the antenna as a function of position of the iris with respect to the transverse plane of the waveguide, the iris always being centered with respect to the patch. In general, the antenna has a VSWR in the waveguide feed on the order of 5:1 at resonance, except for the fully open waveguide which gives rise to a VSWR of 2.9:1 at resonance. Far-field antenna power patterns are observed to be quite broad with H-plane beamwidths on the order of 1300. Maximum antenna gain is seen to be 4.5 dBi with 3 dBi typical. An initial study is made of the microstrip patch antenna fed from a longitudinal waveguide wall. Results indicate that …

From preface: STARPAC documentation is being published as a series of Technical Notes. This Note is the first in the series. It gives an overview of the STARPAC library, defines conventions used in the documentation, provides an example using STARPAC subroutines, and presents general background material. This Note includes information which is essential for using the STARPAC library, and users should be familiar with its contents before attempting to use any STARPAC subroutine.

From preface: This Note documents 16 subroutines for nonlinear least squares regression. Twelve of these compute the least squares estimates, performing either weighted or unweighted analysis with either numerically approximated or user-supplied (analytic) derivatives. The other four are user-callable subroutines for two procedures used within the estimation code: the first selects optimum step sizes for approximating the partial derivatives of the model; and the second checks the validity of a user-supplied derivative subroutine.

Introduction: A reference step-like pulse generator is described which has been developed at NBS. This generator can be used for accurately characterizing the step response of various kinds of trap ient recording equipment (oscilloscopes, waveform recorders, transient digitizers, etc.). Basic design principles are given as well as complete circuit diagrams and descriptions. An analysis of the output stage of the generator is presented together with the circuit models for developing a time-domain computer simulation program using extended- SCEPTRE. Preliminary specifications indicate that the NBS Reference Flat Pulse Generator provides a negative-going reference transition duration (90 to 10 percent) of 600 ps, *20 percent with baseline perturbations of less than *2 percent for less than 5 ns.

From introduction: A new method for determining the radiation characteristics of leakage from electronic equipment for interference studies is described in this report. Basically, an unintentional leakage source is considered to be electrically small, and may be characterized by three equivalent orthogonal electric dipole moments and three equivalent orthogonal magnetic dipole moments. When an unknown source object is placed at the center of a transverse electromagnetic (TEM) cell, its radiated energy couples into the fundamental transmission mode and propagates toward the two output ports of the TEM cell. With a hybrid junction inserted into a loop connecting the cell output ports, one is able to measure the sum and difference powers and the relative phase between the sum and difference outputs. Systematic measurements of these powers and phases at six different source object positions, based on a well-developed theory, are sufficient to determine the amplitudes and phases of the unknown component dipole moments, from which the detailed free-space radiation pattern of the unknown source and the total radiated power can be determined. Results of simulated theoretical examples and an experiment using a spherical dipole radiator are given to illustrate the theory and measurement procedure.

From introduction: For the first time, transfer standards have been developed for measuring 1.064 Pm laser pulses of duration about 10-100 ns, peak irradiance of about 10-8-10-4 W/cm2, and fluences of about 10-16-10-11 J/cm2 . These energy and power measurement devices use PIN and APD silicon detectors, respectively, and can be used as stable transfer standards with total uncertainties (random errors computed at the 95 percent confidence level) of 10 to 15 percent. The system for calibrating these transfer standards is also described and consists of a cw Nd:YAG laser beam acousto-optically modulated to provide low-level laser pulses of known peak power and energy. A detailed evaluation of systematic and random errors is also shown.

From abstract: "Guide for those who design, specify, use, and test military automatic test equipment containing sensors."

Report documenting standard x-ray diffraction powder patterns for various compounds, intended to replace previous data or provide information for new substances. It describes the methods and, for each substance, outlines any previous data as well as information about the sample used and structural data, with a table of diffraction patterns.

Report documenting standard x-ray diffraction powder patterns for various compounds, intended to replace previous data or provide information for new substances. It describes the methods and, for each substance, outlines any previous data as well as information about the sample used and structural data, with a table of diffraction patterns.

Report documenting standard x-ray diffraction powder patterns for various compounds, intended to replace previous data or provide information for new substances. It describes the methods and, for each substance, outlines any previous data as well as information about the sample used and structural data, with a table of diffraction patterns.

Report issued by the U.S. National Bureau of Standards discussing the System Management Facilities for IBM systems. As stated in the introduction, "the purpose of SMF, as stated in the IBM manual, is to provide the means for gathering and recording information that can be used for billing customers or evaluating system usage" (p. 1). This report includes tables, and illustrations.

Report documenting standard x-ray diffraction powder patterns for various compounds, intended to replace previous data or provide information for new substances. It describes the methods and, for each substance, outlines any previous data as well as information about the sample used and structural data, with a table of diffraction patterns.

Report issued by the U.S. National Bureau of Standards discussing specifications of reflectance and proposed nomenclature. As stated in the introduction, "this monograph presents a unified approach to the specification of reflectance in relation to the beam geometry of both the incident and the reflected flux in any reflectometer or in any application of measured reflectance data" (p. 1). This report includes illustrations.

Report presenting a unified approach to the specification of reflectance, in terms of both incident- and reflected- beam geometry. Nomenclature to facilitate this approach is proposed. Nomenclature for categorizing and specifying reflectance quantities for a variety of different beam configurations (both incident and reflected beams) is described, and all are defined and interrelated in terms of the bidirectional reflectance-distribution function. The conditions under which the formalism can be applied, including situations involving considerable sub-surface scattering, are carefully established. The entire treatment is limited to the domain of classical geometrical-optics radiometry and does not take into account interference and diffraction phenomena, such as are frequently encountered with highly coherent radiant flux.

Report discussing optical wedge beam splitters and the basic theory for computing the ratio of the intensity of the incident beam to the intensity of any selected emerging beam and also for computing the direction of the emerging beam, assuming that the wedge angle, index of refraction, angle of incidence, and number of reflections are known.

Report presenting a diagrammatic method for solving angular momentum recoupling problems. It is shown that a few graphical elements with a set of rules for their use lead to the solution of many types of recoupling problems in an intuitive and systematic way. Several examples are given together with exercises to develop the reader's facility with the method.

From Abstract: "This work traces the development of the Loran-C concept from its inception as a 100-kHz pulse hyperbolic navigation system to more recent times when it found a variety of applications to both timing and navigation."

From Abstract: "This publication contains information, useful to the hard of hearing, on several topics relating to hearing and hearing aids. This publication represents an extensive revision of NBS Circular 534, Hearing Aids. It includes new material based upon research conducted at the National Bureau of Standards during the intervening years."

Report presenting the technical background and basis for a new method of evaluating certain performance parameters which are common to all microwave systems. A unique feature of the new measurement concept is its elimination of the precision waveguide and connector requirements for an important class of measurement problems.

From Abstract: "This treatise is a source document containing information on helium resources, production, conservation, thermodynamic properties, liquefaction and refrigeration techniques, transportation and storage of liquid and safety requirements. It also contains a discussion of uses for liquid and cold gas in cryoelectronics, superconductivity, bubble chambers, cryopumping and missile and space systems."