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The Detection of Lyman Alpha Radiation Formed by the Slowing Down of Protons and Tritons Produced by the 3He (n,tp) ReactionA Model Study
No full textThe observation of Lyman alpha (La) radiation produced by the end products of the 3He (n,tp) reaction has suggested the possibility of a new method of cold thermal neutron detection. In order for this goal to be achieved, a basic understanding of how the L? radiation is formed and how it may be detected, is needed. The model study described here is an attempt to provide this basic understanding and to provide quantitative results that can be used in designing future experiments
DIANA NYYSSONEN
No full textDIANA NYYSSONEN
Inducted: 2008
Citation:
For being the first to develop and disseminate the idea of circumventing the classical diffraction limit of an optical microscope by mathematically modeling diffraction effects in order to determine the location of the physical edge in an image. Her research provided the basis for extending the application of optical microscopy, providing unique linewidth SRMs, and enabling significant advances in fabrication and performance of microelectronic devices.
Tenure: 1969-1985
Birth: 1943, Cambridge, Massachusetts
Death: 1997
Education:
Boston University, BA (Physics), 1965
University of Rochester, PhD (Optics), 1975
Positions held:
Physicist, Radiometric Physics Division, 1969 - 1978
Physicist, Electron Devices Division, CEEE, 1979 - 1981
Group Leader, Micrometrology, Semiconductor Materials and Processing Division, CEEE, 1982-1985
Honors:
US Department of Commerce Silver Medal (1980)
BACUS Prize- industry conference in photomask technology (2001)
Memberships:
Fellow, International Society for Optical Engineering
Fellow, Optical Society of America
Society of Photographic Scientists and Engineers
Publications:
More than 40 publications, including:
Nyyssonen, D., “Linewidth Measurement with an Optical Microscope: the Effect of Operating Conditions on Image Profile,” Applied Optics 16, 2223 – 2230 (1977)
Jerke, J. M., Hartman, A. W., Nyyssonen, D., Swing, R. E., Young, R. D., and Keery, W. J., “Comparison of Linewidth Measurements on an SEM/Interferometer System and an Optical Linewidth-Measuring Microscope,” Proceedings SPIE Vol. 100 (1977)
Nyyssonen, D., “Calibration of Optical Systems for Linewidth Measurements on Wafers,” SPIE Proceedings, Vol. 221, 119-126 (1980)
Nyyssonen, D., “Theory of Optical Edge Detection and Imaging of Thick Layers,” J. Opt. Soc. Am., Vol. 72, 1425-1436 (1982)
Nyyssonen, D. and Swing, R.E., “Theoretical Analysis of Optical Microscope,” Accurate Linewidth Measurements on Integrated-Circuit Photomasks, NBS Special Publication 400-43, 16-42 (1980)
Nyyssonen, D. and Larrabee, R.D., “Submicrometer Linewidth Metrology in the Optical Microscope”, Journal of Research, National Bureau of Standards 92, 187-204 (1987
Accelerating scientific discovery through computation and visualization - III. Tight-binding wave functions for quantum dots
No full textThis is the third in a series of articles that describe, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing, visualization, and machine learning to accelerate scientific discovery. In this article we focus on the use of high performance computing and visualization for simulations of nanotechnology
Standardization of 68Ge/68Ga Using Three Liquid Scintillation Counting Based Methods
No full textA solution containing 68Ge in equilibrium with its daughter, 68Ga, has been standardized for the first time at the National Institute of Standards and Technology (NIST) using 3 liquid scintillation-based techniques: live-timed 4 pi beta-gamma anticoincidence (LTAC) counting, the Triple-to-Double Coincidence Ratio (TDCR) method, and 3H-standard efficiency tracing with the CIEMAT1/NIST (CNET) method. The LTAC technique is much less dependent on level scheme data and model-dependent parameters and was thus able to provide a reference activity concentration value for the master solution with a combined standard uncertainty of about 0.3 %. The other two methods gave activity concentration values with respective differences from the reference value of +1.2 % and -1.5 %, which were still within the experimental uncertainties. Measurements made on the NIST "4 pi"gamma secondary standard ionization chamber allowed for the determination of calibration factors for that instrument, allowing future calibrations to be made for 68Ge/68Ga without the need for a primary measurement. The ability to produce standardized solutions of 68Ge presents opportunities for the development of a number of NIST-traceable calibration sources with very low (<1 %) relative standard uncertainties that can be used in diagnostic medical imaging
Bilateral Optical Power Meter Comparison Between NIST and CENAM
No full textWe describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and Centro Nacional De Metrologia (CENAM-Mexico). Open beam (free field) and optical-fiber-based measurements at wavelengths of 1302 nm and 1546 nm are reported. Both laboratories' reference standards were compared by means of a temperature-controlled optical trap detector. Measurements showed a largest difference of less than 3.4 parts in 10(3), which is within the combined expanded (k = 2) uncertainty for the laboratories' reference standards
Gauge blocks - A Zombie technology
No full textGauge blocks have been the primary method for disseminating length traceability for over 100 years. Their longevity was based on two things: the relatively low cost of delivering very high accuracy to users, and the technical limitation that the range of high precision gauging systems was very small. While the first reason is still true, the second factor is being displaced by changes in measurement technology since the 1980s. New long range sensors do not require master gauges that are nearly the same length as the part being inspected, and thus one of the primary attributes of gauge blocks, wringing stacks to match the part, is 110 longer needed. Relaxing the requirement that gauges wring presents an opportunity to develop new types of end standards that would increase the accuracy and usefulness of gauging systems
Portrait of Richard E. Harris
No full textRichard E. Harris worked in the NIST Boulder Labs in the Cryoelectronic Metrology and Quantum Electromagnetics Division
Development of a thin film magnetic moment reference material
No full textIn this paper we present the development of a magnetic moment reference material for low moment magnetic samples. We first conducted an inter-laboratory comparison to determine the most useful sample dimensions and magnetic properties for common instruments such as vibrating sample magnetometers (VSM), SQUIDs, and alternating gradient field magnetometers. The samples were fabricated and then measured using a vibrating sample magnetometer. Their magnetic moments were calibrated by tracing back to the NIST YIG sphere, SRM 2853
The Pole Term in Linear Response Theory: An Example From the Transverse Response of the Electron Gas
No full textIn linear response theory, the dielectric response at zero frequency sometimes appears to violate the f-sum rule, which has apparent implications for causality. Here, we study the origin of this apparent discrepancy, focusing on Lindhard's formula for the transverse response of the electron gas. At non-zero frequency, first-order poles contribute to the imaginary part of the dielectric function in the usual way. At zero frequency, second-order poles contribute in a way which forces a careful consideration of the notation of summation and integration to avoid an error. A compact formula for the contribution of the second-order poles is presented. The sense in which the f-sum rule is satisfied is discussed