25 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Amplification"  
Results: 1 - 24 next
open access

Field and Current Amplification in the SSPX Spheromak

Description: Results are presented from experiments relating to magnetic field generation and current amplification in the SSPX spheromak. The SSPX spheromak plasma is driven by DC coaxial helicity injection using a 2MJ capacitor bank. Peak toroidal plasma currents of up to 0.7MA and peak edge poloidal fields of 0.3T are produced; lower current discharges can be sustained up to 3.5msec. When edge magnetic fluctuations are reduced below 1% by driving the plasma near threshold, it is possible to produce plasm… more
Date: October 8, 2002
Creator: Hill, D. N.; Blumer, R. H.; Cohen, B. I.; Hooper, E. B.; McLean, H. S.; Moller, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Final Report: Deconvolution of Adaptive Optics Images of Titan, Neptune, and Uranus

Description: This project involved images of Titan, Neptune, and Uranus obtained using the 10-meter W.M. Keck II Telescope and its adaptive optics system. An adaptive optics system corrects for turbulence in the Earth's atmosphere by sampling the wavefront and applying a correction based on the distortion measured for a known source within the same isoplanatic patch as the science target (for example, a point source such as a star). Adaptive optics can achieve a 10-fold increase in resolution over that obta… more
Date: December 20, 2002
Creator: Gibbard, S & Marchis, F
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Science& Technology Review October 2002

Description: The October 2002 issue of Science and Technology Review has the following articles: (1) Applied Science Is a Hallmark of This Laboratory--Commentary by Hal Graboske. (2) Sending Up Signals for Genetic Variation--In situ rolling circle amplification promises to advance the detection and treatment of cancer and other diseases. (3) SiMM Is Anything But Simple--Modules of silicon microchannels and microlenses result in the smallest, most powerful, and least expensive laser diode pumps ever. (4) Wor… more
Date: October 1, 2002
Creator: Budil, K S
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Supersensitive in Situ Hybridization by Tyramide Signal Amplification and Nanogold Silver Staining: The Contribution of Autometallography and Catalyzed Reporter Deposition to the Rejuvenation of In Situ Hybridization

Description: It is peculiar that in situ hybridization (ISH), a technique with many similarities to immunohistochemistry (IHC), has not enjoyed the phenomenal growth in both basic research and clinical applications as has its sister technique IHC. Since the late 1970s, when immunoperoxidase techniques began to be applied to routine diagnostic material and to numerous research applications, there has been a natural evolution of the IHC procedure. Namely, only a few primary antibodies were available commercia… more
Date: April 17, 2002
Creator: Tubbs, Raymond R.; Pettay, James; Grogan, Thomas; Powell, R. D.; Cheung, Annie L. M.; Hainfeld, James et al.
Item Type: Refine your search to only Book
Partner: UNT Libraries Government Documents Department
open access

Development of an Automated Microfluidic System for DNA Collection, Amplification, and Detection of Pathogens

Description: This project was focused on developing and testing automated routines for a microfluidic Pathogen Detection System. The basic pathogen detection routine has three primary components; cell concentration, DNA amplification, and detection. In cell concentration, magnetic beads are held in a flow cell by an electromagnet. Sample liquid is passed through the flow cell and bacterial cells attach to the beads. These beads are then released into a small volume of fluid and delivered to the peltier devi… more
Date: December 1, 2002
Creator: Hagan, Bethany S. & Bruckner-Lea, Cynthia J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Simulations of electron cloud build-up and saturation in the APS.

Description: In studies with positron beams in the Advanced Photon Source, a dramatic amplification was observed in the electron cloud for certain bunch current and bunch spacings. In modeling presented previously, we found qualitative agreement with the observed beam-induced multipacting condition, provided reasonable values were chosen for the secondary electron yield parameters, including the energy distribution. In this paper, we model and discuss the build-up and saturation process observed over long b… more
Date: June 13, 2002
Creator: Harkay, K.; Rosenberg, R.; Furman, M. & Pivi, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Synergies between electromagnetic calorimetry and PET

Description: The instrumentation used for the nuclear medical imaging technique of Positron Emission Tomography (PET) shares many features with the instrumentation used for electromagnetic calorimetry. Both fields can certainly benefit from technical advances in many common areas, and this paper discusses both the commonalties and the differences between the instrumentation needs for the two fields. The overall aim is to identify where synergistic development opportunities exist. While such opportunities ex… more
Date: July 30, 2002
Creator: Moses, William W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Kinetic Alfven Waves at the Magnetopause--Mode Conversion, Transport and Formation of LLBL

Description: At the magnetopause, large amplitude, low-frequency (ULF), transverse MHD waves are nearly always observed. These waves likely result from mode conversion of compressional MHD waves observed in the magnetosheath to kinetic Alfven waves at the magnetopause where there is a steep gradient in the Alfven velocity [Johnson and Cheng, Geophys. Res. Lett. 24 (1997) 1423]. The mode-conversion process can explain the following wave observations typically found during satellite crossings of the magnetopa… more
Date: May 31, 2002
Creator: Johnson, Jay R. & Cheng, C. Z.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Spontaneous and amplified radiation at the initial stage of a SASE FEL.

Description: At the initial stage of a self-amplified spontaneous emission (SASE) free-electron laser (FEL), spontaneous undulator radiation in certain experimental configurations can dominate the amplified signal over an extended undulator distance. In this paper they study both the spontaneous and the amplified radiation in the framework of the paraxial wave equation and determine the transition from the dominance of spontaneous emission to exponential amplification. They compare theoretical expectations … more
Date: November 1, 2002
Creator: Huang, Z. & Kim, K. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Cutting Costs by Locating High Production Wells: A Test of the Volcano seismic Approach to Finding ''Blind'' Resources

Description: In the summer of 2000, Duke University and the Kenyan power generation company, KenGen, conducted a microearthquake monitoring experiment at Longonot volcano in Kenya. Longonot is one of several major late Quaternary trachyte volcanoes in the Kenya Rift. They study was aimed at developing seismic methods for locating buried hydrothermal areas in the Rift on the basis of their microearthquake activity and wave propagation effects. A comparison of microearthquake records from 4.5 Hz, 2 Hz, and br… more
Date: June 6, 2002
Creator: Shalev, Eylon; Malin, Peter E. & McCausland, Wendy
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Processes the Govern Helicity Injection in the SSPX Spheromak

Description: The physical processes that govern the gun-voltage and give rise to field generation by helicity injection are surveyed in the Sustained Spheromak Physics experiment (SSPX) using internal magnetic field probes and particular attention to the gun-voltage. SSPX is a gun-driven spheromak, similar in many respects to CTX, although differing substantially by virtue of a programmable vacuum field configuration. Device parameters are: diameter = 1m, I{sub tor}-400kA, T{sub e}{approx}120eV, t{sub pulse… more
Date: October 8, 2002
Creator: Woodruff, S; Stallard, B W; Holcomb, C T & Cothran, C
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Injector-Amplifier Design for Tabletop Ne-Like X-Ray Lasers

Description: We report new results using the LLNL COMET laser to evaluate the effectiveness of different target architectures to improve the output and characteristics of the transient x-ray laser scheme. Surprising observations were found when the laser line focus irradiating a single slab Cr or Fe target was divided into two or three distinct plasma column sections with millimeter scale gaps between each plasma. The Ne-like 3p {sup 1}S{sub 0} {yields} 3s {sup 1}P{sub 1} 28.5 nm and 25.5 nm x-ray laser lin… more
Date: October 7, 2002
Creator: Dunn, J.; Osterheld, A. L.; Faenov, A. Ya.; Pikuz, T. A. & Shlyaptsev, V. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Spheromak Impedance and Current Amplification

Description: It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, {tau}{sub REC}, which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI{sub TOR}{sup 2}/dt {approx} I{sup 2}/{tau}{sub REC} - I{sub TOR}{sup 2}/{tau}{sub closed} where I is the gun current, I{sub TOR} is the spheromak toroidal current and {tau}{sub CLOSED} is the ohmic decay time of the spheromak. Achieving high cur… more
Date: January 31, 2002
Creator: Fowler, T K; Hua, D D & Stallard, B W
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Route to High Temperatures by Current Amplification in the Sustained Spheromak Physics Experiment (SSPX)

Description: For the spheromak to be attractive as a reactor concept it would be necessary to sustain the configuration with a low recycling power, reflected in the current amplification factor: A{sub 1} = I{sub tor}/I{sub gun}, where I{sub tor} is the toroidal current and I{sub gun} is the gun current. It is understood that A{sub 1} needs to be around 60 for a reactor [1], although the highest obtained so far in the spheromak has been {approx}3 [2]. The spheromak is a simply connected toroidal confinement … more
Date: June 11, 2002
Creator: Woodruff, S.; Holbomb, C. T.; Stallard, B. W.; Hill, D. N.; Hooper, E. B.; McLean, H. S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hybrid Chirped Pulse Amplification

Description: We present a novel chirped pulse amplification method which combines optical parametric amplification and laser amplification. We have demonstrated this hybrid CPA concept with a combination of beta-barium borate and Ti:sapphire. High-efficiency, multi-terawatt compatible amplification is achieved without gain narrowing and without electro-optic modulators using a simple commercial pump laser.
Date: May 7, 2002
Creator: Jovanovic, I & Barty, C P J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Comparison of Anti-Reflective Coated and Uncoated Surfaces Figured by Pitch-Polishing and Magneto-Rheological Processes

Description: When completed, the National Ignition Facility (NIF) will provide laser energies in the Mega-joule range. Successful pulse amplification to these extremely high levels requires that all small optics, found earlier in the beamline, have stringent surface and laser fluence requirements. In addition, they must operate reliably for 30 years constituting hundreds of thousands of shots. As part of the first four beamlines, spherical and aspherical lenses were required for the beam relaying telescopes… more
Date: November 8, 2002
Creator: Chow, R.; Thomas, M. D.; Bickel, R. & Taylor, J. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Final Report BW Sample Collection& Preparation Device

Description: The objective of this project was to develop the technique needed to prepare a field collected sample for laboratory analysis and build a portable integrated biological detection instrument with new miniaturized and automated sample purification capabilities. The device will prepare bacterial spores, bacterial vegetative cells, and viral particles for PCR amplification.
Date: January 31, 2002
Creator: Koopman, R P; Belgrader, P; Meyer, G; Benett, W J; Richards, J B; Hadley, D R et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Analysis of Site Response at U1A Hole at the Nevada Test Site From Weak Motion Readings

Description: We utilize weak motion recordings to evaluate the site response at the U1A hole, Nevada Test site to determine the effect on potential ground motion at the drift of the U1A hole 962 ft deep. We estimated the site response amplification of ground motion at the surface relative to the drift with the spectral ratio method. We utilized Fourier amplitude and absolute acceleration response spectra, and confined our study to frequencies of 0.5 to 25.0 Hz (.04 to 2.0 s periods). We identified 8 earthqu… more
Date: May 21, 2002
Creator: Hutchings, L & Furrey, L
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation on Soft X-Ray Lasers with a Picosecond-Laser-Irradiated Gas Puff Target

Description: We present results of experimental studies on transient gain soft x-ray lasers with a picosecond-laser-irradiated gas puff target. The target in a form of an elongated gas sheet is formed by pulsed injection of gas through a slit nozzle using a high-pressure electromagnetic valve developed and characterized at the Institute of Optoelectronics. The x-ray laser experiments were performed at the Lawrence Livermore National Laboratory using the tabletop Compact Multipulse Terawatt (COMET) laser to … more
Date: October 9, 2002
Creator: Fiedorowiez, H.; Bartnik, A.; Jarocki, R.; Rakowski, R.; Dunn, J.; Smith, R. F. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Organized Oscillations of Initially-Turbulent Flow Past a Cavity

Description: Flow past an open cavity is known to give rise to self-sustained oscillations in a wide variety of configurations, including slotted-wall, wind and water tunnels, slotted flumes, bellows-type pipe geometries, high-head gates and gate slots, aircraft components and internal piping systems. These cavity-type oscillations are the origin of coherent and broadband sources of noise and, if the structure is sufficiently flexible, flow-induced vibration as well. Moreover, depending upon the state of th… more
Date: September 17, 2002
Creator: Lin, J. C. & Rockwell, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Comments on optical stochastic cooling

Description: An important necessary condition for transverse phase space damping in the optical stochastic cooling with transit-time method is derived. The longitudinal and transverse damping dynamics for the optical stochastic cooling is studied. The authors also obtain an optimal laser focusing condition for laser-beam interaction in the correction undulator. The amplification factor and the output peak power of the laser amplifier are found to differ substantially from earlier publications. The required … more
Date: October 8, 2002
Creator: Ng, K. Y.; Lee, S. Y. & Zhang, Y. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electron cloud effects at positron/electron (e+/e-) machines and electron cloud diagnostics.

Description: Background electrons are ubiquitous in high-intensity particle accelerators. Under certain operating conditions, amplification of the electron cloud can occur. The beam-cloud interaction can seriously degrade the accelerator performance with effects that range from vacuum degradation to collective beam instabilities. Although electron cloud effects (ECEs) were first observed 20 years ago in a proton ring, in recent years, they have been widely observed and intensely studied in e{sup +}/e{sup -}… more
Date: July 9, 2002
Creator: Harkay, K.; Rosenberg, R. A.; Macek, R. J.; Browman, A. & Wang, T. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Simulations of electron cloud build-up and saturation in the APS

Description: In studies with positron beams in the Advanced Photon Source, a dramatic amplification was observed in the electron cloud for certain bunch current and bunch spacings. In modeling presented previously, we found qualitative agreement with the observed beam-induced multipacting condition, provided reasonable values were chosen for the secondary electron yield parameters, including the energy distribution. In this paper, we model and discuss the build-up and saturation process observed over long b… more
Date: June 19, 2002
Creator: Harkay, K. C.; Rosenberg, R. A.; Furman, M. A. & Pivi, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen