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Prospects for higgs search at D0

Description: The D0 experiment is recording physics quality data. Both the detector and the accelerator performance are continually improving. We are studying issues such as the b{bar b} mass resolution, b-jet tagging efficiency, missing E{sub T} resolution, and backgrounds to Higgs processes. We look forward to seeing exciting results. The status of the Higgs search at the upgraded D0 detector is discussed.
Date: April 30, 2003
Creator: Snyder, Scott S.
Partner: UNT Libraries Government Documents Department

Inspection 13.2 nm table-top full-field microscope

Description: We present results on a table-top microscope that uses an EUV stepper geometry to capture full-field images with a halfpitch spatial resolution of 55 nm. This microscope uses a 13.2 nm wavelength table-top laser for illumination and acquires images of reflective masks with exposures of 20 seconds. These experiments open the path to the realization of high resolution table-top imaging systems for actinic defect characterization.
Date: February 23, 2009
Creator: Brizuela, F.; Wang, Y.; Brewer, C. A.; Pedaci, F.; Chao, W.; Anderson, E. H. et al.
Partner: UNT Libraries Government Documents Department

Towards sub-10 nm resolution zone plates using the overlaynanofabrication processes

Description: Soft x-ray zone plate microscopy has proven to be a valuable imaging technique for nanoscale studies. It complements nano-analytic techniques such as electron and scanning probe microscopies. One of its key features is high spatial resolution. We developed an overlay nanofabrication process which allows zone plates of sub-20 nm zone widths to be fabricated. Zone plates of 15 nm outer zones were successfully realized using this process, and sub-15 nm resolution was achieved with these zone plates. We extend the overlay process to fabricating zone plates of 12 nm outer zones, which is expected to achieve 10 nm resolution. In addition, we have identified a pathway to realizing sub-10 nm resolution, high efficiency zone plates with tilted zones using the overlay process.
Date: January 23, 2008
Creator: Chao, Weilun; Anderson, Erik H.; Fischer, Peter & Kim, Dong-Hyun
Partner: UNT Libraries Government Documents Department

A high resolution scale-of-four

Description: A high resolution scale-of-four has been developed to be used in conjunction with the nuclear particle detection devices in applications where the counting rate is unusually high. Specifically, it is intended to preceed the commercially available medium resolution scaling circuits and so decrease the resolving time of the counting system. The circuit will function reliably on continuously recurring pulses separated by less than 0.1 μ sec. It will resolve two pulses (occuring at a moderate repetition rate) which are spaced at 0.04 μ sec. A five-volt input signal is sufficient to actuate the device.
Date: August 25, 1949
Creator: Fitch, V.
Partner: UNT Libraries Government Documents Department

Latest results from the SEMATECH Berkeley extreme ultraviolet microfield exposure tool

Description: Microfield exposure tools (METs) continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the 0.3 numerical aperture SEMATECH Berkeley MET operating as a resist and mask test center. Here they present an update on the tool summarizing some of the latest test and characterization results. they provide an update on the long-term aberration stability of the tool and present line-space imaging in chemically amplified photoresist down to the 20-nm half-pitch level. Although resist development has shown substantial progress in the area of resolution, line-edge-roughness (LER) remains a significant concern. Here we present a summary of recent LER performance results and consider the effect of mask contributors to the LER observed from the SEMATECH Berkeley microfield tool.
Date: September 2, 2008
Creator: Naulleau, Patrick; Anderson, Christopher N.; Chiu, Jerrin; Dean, Kim; Denham, Paul; George, Simi et al.
Partner: UNT Libraries Government Documents Department

On Issues of Precision for Hardware-based Volume Visualization

Description: This paper discusses issues with the limited precision of hardware-based volume visualization. We will describe the compositing OVER operator and how fixed-point arithmetic affects it. We propose two techniques to improve the precision of fixed-point compositing and the accuracy of hardware-based volume visualization. The first technique is to perform dithering of color and alpha values. The second technique we call exponent-factoring, and captures significantly more numeric resolution than dithering, but can only produce monochromatic images.
Date: April 11, 2003
Creator: LaMar, E C
Partner: UNT Libraries Government Documents Department

One-Angstrom microscope update

Description: The One-Angstrom Microscope project has attained its goal, and is now producing images down to 1 Angstrom resolution. We have demonstrated transmission electron microscopy of defect structures down to a resolution of 1.1 Angstrom, with evidence that 0.89 Angstrom will be possible. This level of resolution will soon be made available to all those NCEM users who have a requirement for sub-Angstrom resolution.
Date: April 4, 1999
Creator: O'Keefe, Michael A.
Partner: UNT Libraries Government Documents Department

Atmospheric test models and numerical experiments for the simulation of the global distribution of weather data transponders

Description: A proposal has been made to establish a high density global network of atmospheric micro transponders to record time, temperature, and wind data with time resolution of {le} 1 minute, temperature accuracy of {+-} 1 K, spatial resolution no poorer than {approx}3km horizontally and {approx}0.1km vertically, and 2-D speed accuracy of {le} 1m/s. This data will be used in conjunction with advanced numerical weather prediction models to provide increases in the reliability of long range weather forecasts. Major advances in data collection technology will be required to provide the proposed high-resolution data collection network. Systems studies must be undertaken to determine insertion requirements, spacing, and evolution of the transponder ensemble, which will be used to collect the data. Numerical models which provide realistic global weather pattern simulations must be utilized in order to perform these studies. A global circulation model with a 3{sup o} horizontal resolution has been used for initial simulations of the generation and evolution of transponder distributions. These studies indicate that reasonable global coverage of transponders can be achieved by a launch scenario consisting of the sequential launch of transponders at specified heights from a globally distributed set of launch sites.
Date: August 25, 1999
Creator: Grossman, A & Molenkamp, C R
Partner: UNT Libraries Government Documents Department

Atomic Resolution Imaging with a sub-50 pm Electron Probe

Description: Using a highly coherent focused electron probe in a 5th order aberration-corrected transmission electron microscope, we report on resolving a crystal spacing less than 50 pm. Based on the geometrical source size and residual coherent and incoherent axial lens aberrations, an electron probe is calculated, which is theoretically capable of resolving an ideal 47 pm spacing with 29percent contrast. Our experimental data show the 47 pm spacing of a Ge 114 crystal imaged with 11-18percent contrast at a 60-95percent confidence level, providing the first direct evidence for sub 50-pm resolution in ADF STEM imaging.
Date: March 2, 2009
Creator: Erni, Rolf P.; Rossell, Marta D.; Kisielowski, Christian & Dahmen, Ulrich
Partner: UNT Libraries Government Documents Department


Description: The authors describe experiments with liquid-xenon-filled wire chambers operating in the proportional mode and the difficulty of achieving useful gain when the anode wires have a spacing < 1 mm. As a result, they have largely turned our attention to chambers with closely spaced wires operated in the ionization mode. They have previously demonstrated a spatial resolution of 15 {micro} rms in this mode, using a 5-wire chamber and a collimated alpha source. They describe the construction of two small high-resolution test chambers to be filled with liquid argon, krypton, or xenon. The chambers consist of two flat cathodes 1 to 2.5 mm apart with a wire plane between them. The wire plane is an array of 24 wires, 5 {micro} in diameter, spaced on 20-{micro} centers, and a charge amplifier is attached to each wire. The space resolution (expected rms < 20 {micro}), time resolution (expected rms < 50 ns), and efficiency will be measured in an accelerator beam. Chambers of this type with only a few hundred wires have sufficient area to cover nearly every beam at NAL.
Date: April 1, 1973
Creator: Derenzo, S.E.; Schwemin, A.; Smits, R.G.; Zaklad, H. & Alvarez, L.W.
Partner: UNT Libraries Government Documents Department

Soft X-Ray Imaging of spin dynamics at high spatial and temporalresolution

Description: Soft X-ray microscopy provides element specific magnetic imaging with a spatial resolution down to 15nm. At XM-1, the full-field soft X-ray microscope at the Advanced Light Source in Berkeley, a stroboscopic pump and probe setup has been developed to study fast magnetization dynamics in ferromagnetic elements with a time resolution of 70ps which is set by the width of the X-ray pulses from the synchrotron. Results obtained with a 2 {micro}m x 4 {micro}m x 45nm rectangular permalloy sample exhibiting a seven domain Landau pattern reveal dynamics up to several nsec after the exciting magnetic field pulse. Domain wall motion, a gyrotropic vortex motion, and a coupling between vortices in the rectangular geometry are observed.
Date: June 1, 2007
Creator: Mesler, Brooke L.; Fischer, Peter; Chao, Weilun & Anderson, Erik H.
Partner: UNT Libraries Government Documents Department

A multi-threshold sampling method for TOF PET signal processing

Description: As an approach to realizing all-digital data acquisition for positron emission tomography (PET), we have previously proposed and studied a multithreshold sampling method to generate samples of a PET event waveform with respect to a few user-defined amplitudes. In this sampling scheme, one can extract both the energy and timing information for an event. In this paper, we report our prototype implementation of this sampling method and the performance results obtained with this prototype. The prototype consists of two multi-threshold discriminator boards and a time-to-digital converter (TDC) board. Each of the multi-threshold discriminator boards takes one input and provides up to 8 threshold levels, which can be defined by users, for sampling the input signal. The TDC board employs the CERN HPTDC chip that determines the digitized times of the leading and falling edges of the discriminator output pulses. We connect our prototype electronics to the outputs of two Hamamatsu R9800 photomultiplier tubes (PMTs) that are individually coupled to a 6.25 x 6.25 x 25mm{sup 3} LSO crystal. By analyzing waveform samples generated by using four thresholds, we obtain a coincidence timing resolution of about 340 ps and an {approx}18% energy resolution at 511 keV. We are also able to estimate the decay-time constant from the resulting samples and obtain a mean value of 44 ns with an {approx}9 ns FWHM. In comparison, using digitized waveforms obtained at a 20 GSps sampling rate for the same LSO/PMT modules we obtain {approx}300 ps coincidence timing resolution, {approx}14% energy resolution at 511 keV, and {approx}5 ns FWHM for the estimated decay-time constant. Details of the results on the timing and energy resolutions by using the multi-threshold method indicate that it is a promising approach for implementing digital PET data acquisition.
Date: February 2, 2009
Creator: Kim, Heejong; Kao, Chien-Min; Xie, Q.; Chen, Chin-Tu; Zhou, L.; Tang, F. et al.
Partner: UNT Libraries Government Documents Department

2D spatial gain profiles in multiple-pulse driven Ne-like Ge lasers

Description: In this paper, we present the direct spatial measurement of the two-dimensional gain profiles for the Ne-like Ge 196 Å laser line using a slab target illuminated by the multiple pulse technique. To understand the spatial dependence for Ge plasmas driven by a series of 100 ps pulses 400 ps apart we did a series of Nova experiments backlighting short Ge amplifiers. Two-dimensional, high-resolution, spatial images of the 196 Å laser emission from the output aperture of the amplifiers were measured to determine the spatial position of the gain. The amplifier lengths were chosen to be short enough to avoid the significant refraction effects which have dominated the analysis of previous near field imaging experiments. To assure good temporal overlap, the traveling wave geometry was used to illuminate both the amplifier and backlighter. The amplifier design included a wire fiducial that provided an absolute spatial reference and avoided the usual difficulty of determining the location of the target surface. We compare the measured spatial gain profiles with simulations done using LASNEX, which calculates the hydrodynamic evolution of the plasma, and XRASER, which uses the temperatures and densities from LASNEX to do the gain and kinetics calculations.
Date: September 21, 1998
Creator: Dunn, J; Li, Y; Nilsen, J & Osterheld, A L
Partner: UNT Libraries Government Documents Department

Developing tiled projection display systems

Description: Tiled displays are an emerging technology for constructing high-resolution semi-immersive visualization environments capable of presenting high-resolution images from scientific simulation [EVL, PowerWall]. In this way, they complement other technologies such as the CAVE [Cruz-Niera92] or ImmersaDesk, [Czernuszenko97], which by design give up pure resolution in favor of width of view and stereo. However, the largest impact may well be in using large-format tiled displays as one of possibly multiple displays in building ''information'' or ''active'' spaces that surround the user with diverse ways of interacting with data and multimedia information flows [IPSI, Childers00, Raskar98, ROME, Stanford, UNC]. These environments may prove to be the ultimate successor of the desktop metaphor for information technology work.
Date: June 8, 2000
Creator: Hereld, M.; Judson, I. R.; Paris, J. & Stevens, R. L.
Partner: UNT Libraries Government Documents Department

Scaling behavior in interference lithography

Description: Interference lithography is an emerging, technology that provides a means for achieving high resolution over large exposure areas (approximately 1 m{sup 2}) with virtually unlimited depth of field. One- and two-dimensional arrays of deep submicron structures can be created using near i-line wavelengths and standard resist processing. In this paper, we report on recent advances in the development of this technology, focusing, in particular, on how exposure latitude and resist profile scale with interference period We present structure width vs dose curves for periods ranging from 200 nm to 1 um, demonstrating that deep submicron structures can be generated with exposure latitudes exceeding 30%. Our experimental results are compared to simulations based on PROLITIV2.
Date: February 27, 1998
Creator: Agayan, R.R.; Banyai, W.C. & Fernandez, A.
Partner: UNT Libraries Government Documents Department

Optimizing receiver configurations for resolution of equivalent dipole polarizabilities in situ

Description: Equivalent dipole polarizabilities are a succinct way to summarize the inductive response of an isolated conductive body at distances greater than the scale of the body. At any time lag or frequency, an equivalent dipole polarizability response is comprised of 9 parameters; six specifying an equivalent dipole polarizability matrix (which is symmetric) and three specifying the apparent location of the body center. Smith and Morrison (2002) give equations for calculating uncertainties in equivalent dipole polarizability and position based on analysis of an iterative linearized inversion. Here, the root mean squared uncertainty in polarizability is weighted and summed over a number of control points and minimized using an evolutionary algorithm for a number of instrument designs. Three families of designs are presented: single transmitter systems for use on a 2-D grid of positions with negligible error in relative instrument location, two transmitter systems for use on a line of positions with negligible error in relative instrument location, and three transmitter systems for stand alone use. Results for the one and two transmitter systems are strongly degraded by errors in instrument position, whereas the three transmitter systems are insensitive to instrument positioning errors.
Date: February 12, 2004
Creator: Smith, J. Torquil & Morrison, H. Frank
Partner: UNT Libraries Government Documents Department

High Resolution Upgrade for Core-level Photoemission Spectroscopy

Description: Upgraded the high resolution core-level photoemission beamline U4A at the National Synchrotron Light Source (NSLS) so that it has higher resolution ({approx}30-50 meV) over a broader spectral range (10-200 eV) than is currently available at any other photoemission beamline at NSLS. Such an upgraded beamline will prove to be extremely useful in new studies of bimetallic systems and semiconductor interfaces.
Date: August 31, 1999
Creator: Madey, T. E.
Partner: UNT Libraries Government Documents Department


Description: The state of the pulse-height analyzing art is reviewed with particular emphasis on the developments of the past two years. The discussion includes consideration of multidimensional instruments, calibration-stabilizing techniques, and some of the auxiliary features that are becoming increasingly available on commercial instruments. Possible future developments with respect to resolving time and memory organization is discussed briefly. (auth)
Date: June 1, 1962
Creator: Chase, R.L.
Partner: UNT Libraries Government Documents Department

OPM Cybersecurity Incident Information

Description: A report about OPM dealing with a cyber security incident which suggested that approximately 4 million individuals whose information that may have been compromised.
Date: June 4, 2015
Creator: United States. Office of Personnel Management.
Partner: UNT Libraries Government Documents Department

Mask roughness induced LER: a rule of thumb -- paper

Description: Much work has already been done on how both the resist and line-edge roughness (LER) on the mask affect the final printed LER. What is poorly understood, however, is the extent to which system-level effects such as mask surface roughness, illumination conditions, and defocus couple to speckle at the image plane, and currently factor into LER limits. Here, we propose a 'rule-of-thumb' simplified solution that provides a fast and powerful method to obtain mask roughness induced LER. We present modeling data on an older generation mask with a roughness of 230 pm as well as the ultimate target roughness of 50 pm. Moreover, we consider feature sizes of 50 nm and 22 nm, and show that as a function of correlation length, the LER peaks at the condition that the correlation length is approximately equal to the resolution of the imaging optic.
Date: March 12, 2010
Creator: McClinton, Brittany & Naulleau, Patrick
Partner: UNT Libraries Government Documents Department

BER Science Network Requirements Workshop -- July 26-27,2007

Description: The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the US Department of Energy Office of Science, the single largest supporter of basic research in the physical sciences in the United States of America. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 20 years. In July 2007, ESnet and the Biological and Environmental Research (BER) Program Office of the DOE Office of Science organized a workshop to characterize the networking requirements of the science programs funded by the BER Program Office. These included several large programs and facilities, including Atmospheric Radiation Measurement (ARM) Program and the ARM Climate Research Facility (ACRF), Bioinformatics and Life Sciences Programs, Climate Sciences Programs, the Environmental Molecular Sciences Laboratory at PNNL, the Joint Genome Institute (JGI). National Center for Atmospheric Research (NCAR) also participated in the workshop and contributed a section to this report due to the fact that a large distributed data repository for climate data will be established at NERSC, ORNL and NCAR, and this will have an effect on ESnet. Workshop participants were asked to codify their requirements in a 'case study' format, which summarizes the instruments and facilities necessary for the science and the process by which the science is done, with emphasis on the network services needed and the way in which the network is used. Participants were asked to consider three time scales in their case studies--the near term (immediately and up to 12 months in the future), the medium term (3-5 years in the future), and the long term (greater than 5 years in the future). ...
Date: February 1, 2008
Creator: Tierney, Brian L. & Dart, Eli
Partner: UNT Libraries Government Documents Department

Demonstration of 12 nm resolution Fresnel zone plate lens based soft x-ray microscopy

Description: To extend soft x-ray microscopy to a resolution of order 10 nm or better, we developed a new nanofabrication process for Fresnel zone plate lenses. The new process, based on the double patterning technique, has enabled us to fabricate high quality gold zone plates with 12 nm outer zones. Testing of the zone plate with the full-field transmission x-ray microscope, XM-1, in Berkeley, showed that the lens clearly resolved 12 nm lines and spaces. This result represents a significant step towards 10 nm resolution and beyond.
Date: June 5, 2009
Creator: Chao, W.; Kim, J.; Rekawa, S.; Fischer, P. & Anderson, E. H.
Partner: UNT Libraries Government Documents Department