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Intelligent optical design program

Description: Described is a general approach to the development of computer programs capable of designing image-forming optical systems without human intervention and of improving their performance with repeated attempts. The approach utilizes two ideas: (1) interpretation of technical design as a mapping in the configuration space of technical characteristics and (2) development of an intelligent routine that recognizes global optima. Examples of lens systems designed and used in the development of the gen… more
Date: May 4, 1984
Creator: Bohachevsky, I.O.; Viswanathan, V.K. & Woodfin, G.
Partner: UNT Libraries Government Documents Department
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Responsibilities, opportunities and challenges in geophysical exploration

Description: Geophysical exploration for engineering purposes is conducted to decrease the risk in encountering site uncertainties in construction of underground facilities. Current responsibilities, opportunities and challenges for those with geophysical expertise are defined. These include: replacing the squiggly line format, developing verification sites for method evaluations, applying knowledge engineering and assuming responsibility for crucial national problems involving rock mechanics expertise.
Date: May 4, 1982
Creator: Rytle, R. J.
Partner: UNT Libraries Government Documents Department
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Laser heating of solid matter by light pressure-driven shocks

Description: Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D parti… more
Date: May 4, 2007
Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Study of the $\tau^- to 3h^- 2h^+ \nu_\tau$ Decay

Description: The branching fraction of the {tau}{sup -} {yields} 3h{sup -} 2h{sup +} {nu}{sub {tau}} decay (h = {pi}, K) is measured with the BABAR detector to be (8.56 {+-} 0.05 {+-} 0.42) x 10{sup -4}, where the first error is statistical and the second systematic. The observed structure of this decay is significantly different from the phase space prediction, with the {rho} resonance playing a strong role. The decay {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}}, with the f{sub 1}(1285) m… more
Date: May 4, 2005
Creator: Aubert, Bernard; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department
open access

Overview of Beam Instrumentation and Diagnostics for the NSLS-II Project

Description: A new, ultra-bright 3rd generation light source, the NSLS-II Project, is planned to be built at Brookhaven National Laboratory. The light source being developed will have unprecedently small beam horizontal emittance and will provide the radiation sources with a brightness of 3 x 10{sup 21} photons/sec/0.1%BW/mm{sup 2}/mrad{sup 2}. In this paper we present the detailed specifications and a comprehensive description of the planned beam instrumentation system and the first results of the ongoing … more
Date: May 4, 2008
Creator: Singh,O.
Partner: UNT Libraries Government Documents Department
open access

Evaluation of Pinhole Camera Resolution for NSLS-II Storage Ring

Description: The NSLS-II Storage Ring provides ultrabright radiation sources with extra-small sizes of the circulating electron beam. The beam dimensions will be monitored with a pinhole camera. In this paper they discuss the possible design and ultimate achievable resolution of the system. Modeling is based on the SRW code as well as numerical calculations using MATLAB.
Date: May 4, 2008
Creator: Pinayev,I.
Partner: UNT Libraries Government Documents Department
open access

Topological Strings And (Almost) Modular Forms

Description: The B-model topological string theory on a Calabi-Yau threefold X has a symmetry group {Lambda}, generated by monodromies of the periods of X. This acts on the topological string wave function in a natural way, governed by the quantum mechanics of the phase space H{sup 3}(X). We show that, depending on the choice of polarization, the genus g topological string amplitude is either a holomorphic quasi-modular form or an almost holomorphic modular form of weight 0 under {Lambda}. Moreover, at each… more
Date: May 4, 2007
Creator: Aganagic, Mina; Bouchard, Vincent & Klemm, Albrecht
Partner: UNT Libraries Government Documents Department
open access

Two-dimensional magnetohydrodynamic calculations for a 5 MJ plasma focus

Description: The performance of a 5 MJ plasma focus is calculated using our two-dimensional magnetohydrodynamic (2-D MHD) code. Two configurations are discussed, a solid and a hollow anode. In the case of the hollow anode, we find an instability in the current sheath which has the characteristics of the short wave length sausage instability. As the current sheath reaches the axis, the numerical solution is seen to break down. Just before this time, plasma parameters take on the characteristic values rho/rho… more
Date: May 4, 1979
Creator: Maxon, S.
Partner: UNT Libraries Government Documents Department
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Spontaneous fission of /sup 259/Md

Description: The mass and kinetic energy distributions of fission fragments from the spontaneous fission of th newly discovered nuclide /sup 259/Md were obtained. /sup 259/Md was identified as the E. C. daughter of /sup 259/No, and was found to decay entirely (> 95%) by spontaneous fission with a 95-min half-life. From the kinetic energies measured for 397 pairs of coincident fragments, a mass distribution was derived that is symmetric with sigma = 13 amu. /sup 259/Md, together with /sup 258/Fm and /sup 259… more
Date: May 4, 1979
Creator: Hulet, E. K.; Wild, J. F.; Lougheed, R. W.; Baisden, P. A.; Landrum, J. H.; Dougan, R. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Lessons from the past and prospects for the future

Description: The author presents his impressions of the conference - that is - major lessons as presented in the talks on nonlinearities and their role in condensed matter physics. (WRF)
Date: May 4, 1986
Creator: Baym, G.
Partner: UNT Libraries Government Documents Department
open access

Jet stability in the lithium fall reactor

Description: A preliminary analysis has been made of the various hydrodynamic aspects involved in the stability of a liquid-lithium jet in a laser-fusion reactor, which comprises a part of LLL's laser fusion power-generation concept. Various physical factors that may affect the jet breakup are delineated, and some approximate calculations are performed to determine their relative influences. Areas of uncertainty are pointed out, along with plans for experimental verification or further theoretical analysis.
Date: May 4, 1978
Creator: Kang, S.W.
Partner: UNT Libraries Government Documents Department
open access

Radiation-to-light converters for nuclear environments: near-infrared emitters

Description: The use of fiber optics in the diagnosis of hostile nuclear environments has brought about a pressing need for the development of suitable radiation-to-light converters. These converters must meet stringent diagnostic requirements of linearity and time response while having a wavelength of emission that is compatible with transmission over relatively long lengths of optical fibers. Initial investigations of two, near-infrared-emitting semiconducting materials - CdTe and GaAs are described. Data… more
Date: May 4, 1981
Creator: Roeske, F.; Rotter, M. D.; Calavan, P. M. & Lutz, S. S.
Partner: UNT Libraries Government Documents Department
open access

Soft x-ray detection with diamond photoconductive detectors

Description: Photoconductive detectors fabricated from natural lla diamonds have been used to measure the x-ray power emitted from laser produced plasmas. The detector was operated without any absorbing filters to distort the x-ray power measurement. The 5.5 eV bandgap of the detector material practically eliminates its sensitivity to scattered laser radiation thus permitting filterless operation. The detector response time or carrier life time was 90 ps. Excellent agreement was achieved between a diamond P… more
Date: May 4, 1990
Creator: Kania, D. R.; Pan, L.; Kornblum, H.; Bell, P.; Landen, O. N. & Pianetta, P.
Partner: UNT Libraries Government Documents Department
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The liquid helium thermosyphon for the GEM detector magnet

Description: The GEM detector magnet, a horizontal solenoid 19.5 m in diameter and wound with a niobium-titanium cable in conduit, will be located with it`s axis 19.5 m below grade. The conductor is wound on the inside of an aluminum bobbin which is cooled by liquid helium which flows by natural convection in a thermosyphon loop from a large storage dewar located at the ground surface. The function of the thermosyphon system is to absorb the environmental heat load as well as any internally generated heat. … more
Date: May 4, 1993
Creator: Warren, R. P.
Partner: UNT Libraries Government Documents Department
open access

An Analysis of Gas Pressure Forming of Superplastic AL 5083 Alloy

Description: Al 5083 disks of a superplastic forming grade were gas-pressure formed to hemispheres and cones at constant forming pressures with and without back pressure. The forming operation was performed using an in-house designed and built biaxial forming apparatus. The temporal change of dome heights of the hemispheres and cones were measured for the different forming and back pressures applied. The flow stresses and strain rates developed at the top of the dome during the forming step were shown to cl… more
Date: May 4, 2001
Creator: Syn, C K; O'Brien, M J; Lesuer, D R & Sherby, O D
Partner: UNT Libraries Government Documents Department
open access

Waveforms Measured in Confined Thermobaric Explosion

Description: Experiments with 1.5-g Shock-Dispersed-Fuel (SDF) charges have been conducted in six different chambers. Both flake Aluminum and TNT were used as the fuel. Static pressure gauges on the chamber wall were the main diagnostic. Waveforms for explosions in air were significantly larger than those in nitrogen - thereby demonstrating a strong thermobaric (combustion) effect. This effect increases as the confinement volume decreases and the mixture richness approaches 1.
Date: May 4, 2007
Creator: Reichenbach, H; Neuwald, P & Kuhl, A L
Partner: UNT Libraries Government Documents Department
open access

Saturation and Dynamic Range of Microchannel Plate-Based X-Ray Imagers

Description: This paper describes recent advances in Monte Carlo simulations of microchannel plate (MCP)–based x-ray detectors, a continuation of ongoing work in this area. A Monte Carlo simulation model has been developed over the past several years by National Security Technologies, LLC (NSTec). The model simulates the secondary electron emission process in an MCP pore and includes the effects of gain saturation. In this work we focus on MCP gain saturation and dynamic range. We have performed modeling an… more
Date: May 4, 2012
Partner: UNT Libraries Government Documents Department
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Numerical Simulations of Thermobaric Explosions

Description: A Model of the energy evolution in thermobaric explosions is presented. It is based on the two-phase formulation: conservation laws for the gas and particle phases along with inter-phase interaction terms. It incorporates a Combustion Model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields. The Model takes into account both the afterburning of the detonation products of the booster wi… more
Date: May 4, 2007
Creator: Kuhl, A L; Bell, J B; Beckner, V E & Khasainov, B
Partner: UNT Libraries Government Documents Department
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Design and Construction of a 15 T, 120 mm Bore Ir Quadrupole Magnet for LARP

Description: Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Large Hadron Collider (LHC) at CERN. Nb{sub 3}Sn conductor is at the present time the only practical superconductor capable of generating fields beyond 10 T. In support of the LHC Phase-II upgrade, the US LHC Accelerator Research Program (LARP) is developing a large bore (120 mm) IR quadrupole (HQ) capable of reaching 15 T at its conductor peak field and a peak gradient of 219 T/m at 1.9 K. While exp… more
Date: May 4, 2009
Creator: Caspi, S.; Cheng, D.; Dietderich, D.; Felice, H.; Ferracin, P.; Hafalia, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Status of Electron-Cloud Build-Up Simulations for the Main Injector

Description: We provide a brief status report on measurements and simulations of the electron cloud in the Fermilab Main Injector. Areas of agreement and disagreement are spelled out, along with their possible significance.
Date: May 4, 2009
Creator: Furman, M. A.; Kourbanis, I. & Zwaska, R. M.
Partner: UNT Libraries Government Documents Department
open access

Nb3Sn superconducting magnets for electron cyclotron resonance ion sources

Description: Electron cyclotron resonance (ECR) ion sources are an essential component of heavy-ion accelerators. Over the past few decades advances in magnet technology and an improved understanding of the ECR ion source plasma physics have led to remarkable performance improvements of ECR ion sources. Currently third generation high field superconducting ECR ion sources operating at frequencies around 28 GHz are the state of the art ion injectors and several devices are either under commissioning or under… more
Date: May 4, 2009
Creator: Ferracin, P.; Caspi, S.; Felice, H.; Leitner, D.; Lyneis, C. M.; Prestemon, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Study on the Mechanical Instability of MICE Coupling Magnets

Description: The superconducting coupling solenoid magnet is one of the key equipment in the Muon Ionization Cooling Experiment (MICE). The coil has an inner radius of 750 mm, length of 281 mm and thickness of 104 mm at room temperature. The peak induction in the coil is about 7.3 T with a full current of 210 A. The mechanical disturbances which might cause the instability of the impregnated superconducting magnet involve the frictional motion between conductors and the cracking of impregnated materials. In… more
Date: May 4, 2011
Creator: Wang, Li; Pan, Heng; Gou, Xing Long; Wu, Hong; Zheng, Shi Xian & Green, Michael A
Partner: UNT Libraries Government Documents Department
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