Shielding of a hadron in a finite e-beam (open access)

Shielding of a hadron in a finite e-beam

The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - the realistic model of an electron beam in accelerators.
Date: May 20, 2012
Creator: A., Elizarov; Litvinenko, V. & Wang, G.
Object Type: Article
System: The UNT Digital Library
Search for Strong Gravity Signatures in Same-Sign Dimuon Final States Using the ATLAS Detector at the LHC (open access)

Search for Strong Gravity Signatures in Same-Sign Dimuon Final States Using the ATLAS Detector at the LHC

None
Date: May 20, 2013
Creator: Aad, Georges
Object Type: Article
System: The UNT Digital Library
Stressmeter Placement at Spent Fuel Test in Climax Granite (open access)

Stressmeter Placement at Spent Fuel Test in Climax Granite

Vibrating wire stressmeters were installed in the Spent Fuel Facility at the Nevada Test Site. These stressmeters will measure the changes in in situ stress during the five-year spent fuel test. Before installation, laboratory tests were conducted to study reproducibility of placement and to develop a program hopefully to reduce corrosion of the stressmeters while in place at the Spent Fuel Facility. These laboratory tests are discussed along with the installation of the stressmeters at the Spent Fuel Facility.
Date: May 20, 1980
Creator: Abey, A. E. & Washington, H. R.
Object Type: Report
System: The UNT Digital Library
Performing Neutron Cross-Section Measurements at RIA (open access)

Performing Neutron Cross-Section Measurements at RIA

The Rare Isotope Accelerator (RIA) is a proposed accelerator for the low energy nuclear physics community. Its goal is to understand the natural abundances of the elements heavier than iron, explore the nuclear force in systems far from stability, and study symmetry violation and fundamental physics in nuclei. To achieve these scientific goals, RIA promises to produce isotopes far from stability in sufficient quantities to allow experiments. It would also produce near stability isotopes at never before seen production rates, as much as 10{sup 12} pps. Included in these isotopes are many that are important to stockpile stewardship, such as {sup 87}Y, {sup 146-50}Eu, and {sup 231}Th. Given the expected production rates at RIA and a reasonably intense neutron source, one can expect to make {approx} 10 {micro}g targets of nuclei with a half-life of {approx}1 day. Thus, it will be possible at RIA to obtain experimental information on the neutron cross section for isotopes that have to date only been determined by theory. There are two methods to perform neutron cross-section measurements, prompt and delayed. The prompt method tries to measure each reaction as it happens. The exact technique employed will depend on the reaction of interest, (n,2n), (n,{gamma}), …
Date: May 20, 2003
Creator: Ahle, L. E.
Object Type: Report
System: The UNT Digital Library
A Neutron Source Facility for Neutron Cross-Section Measurements on Radioactive Targets at RIA (open access)

A Neutron Source Facility for Neutron Cross-Section Measurements on Radioactive Targets at RIA

The stockpile stewardship program is interested in neutron cross-section measurements on nuclei that are a few nucleons away from stability. Since neutron targets do not exist, radioactive targets are the only way to directly perform these measurements. This requires a facility that can provide high production rates for these short-lived nuclei as well as a source of neutrons. The Rare Isotope Accelerator (RIA) promises theses high production rates. Thus, adding a co-located neutron source facility to the RIA project baseline would allow these neutron cross-section measurements to be made. A conceptual design for such a neutron source has been developed, which would use two accelerators, a Dynamitron and a linac, to create the neutrons through a variety of reactions (d-d, d-t, deuteron break-up, p-Li). This range of reactions is needed in order to provide the desired energy range from 10's of keV to 20 MeV. The facility would also have hot cells to perform chemistry on the radioactive material both before and after neutron irradiation. The present status of this design and direction of future work will be discussed.
Date: May 20, 2003
Creator: Ahle, L. E.; Bernstein, L.; Rusnak, B. & Berio, R.
Object Type: Article
System: The UNT Digital Library
Thermal Analysis of SRF Cavity Couplers Using Parallel Multi physics Tool TEM3P (open access)

Thermal Analysis of SRF Cavity Couplers Using Parallel Multi physics Tool TEM3P

SLAC has developed a multi-physics simulation code TEM3P for simulating integrated effects of electromagnetic, thermal and structural loads. TEM3P shares the same software infrastructure with SLAC's parallel finite element electromagnetic codes, thus enabling all physics simulations within a single framework. The finite-element approach allows high-fidelity, high-accuracy simulations and the parallel implementation facilitates large-scale computation with fast turnaround times. In this paper, TEM3P is used to analyze thermal loading at coupler end of the JLAB SRF cavity.
Date: May 20, 2009
Creator: Akcelik, V; Lee, L. Q.; Li, Z.; Ng, C. K.; Ko, K.; Cheng, G. et al.
Object Type: Article
System: The UNT Digital Library
Letter to Mr. Frank Rom, National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio (open access)

Letter to Mr. Frank Rom, National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio

None
Date: May 20, 1965
Creator: Albaugh, F. W.
Object Type: Report
System: The UNT Digital Library
Trip report to General Dynamics, Fort Worth, Texas (open access)

Trip report to General Dynamics, Fort Worth, Texas

None
Date: May 20, 1971
Creator: Albertin, L.
Object Type: Report
System: The UNT Digital Library
Extreme ultraviolet lithography: A few more pieces of the puzzle (open access)

Extreme ultraviolet lithography: A few more pieces of the puzzle

The work described in this dissertation has improved three essential components of extreme ultraviolet (EUV) lithography: exposure tools, photoresist, and metrology. Exposure tools. A field-averaging illumination stage is presented that enables nonuniform, high-coherence sources to be used in applications where highly uniform illumination is required. In an EUV implementation, it is shown that the illuminator achieves a 6.5% peak-to-valley intensity variation across the entire design field of view. In addition, a design for a stand-alone EUV printing tool capable of delivering 15 nm half-pitch sinusoidal fringes with available sources, gratings and nano-positioning stages is presented. It is shown that the proposed design delivers a near zero line-edge-rougness (LER) aerial image, something extremely attractive for the application of resist testing. Photoresist. Two new methods of quantifying the deprotection blur of EUV photoresists are described and experimentally demonstrated. The deprotection blur, LER, and sensitivity parameters of several EUV photoresists are quantified simultaneously as base weight percent, photoacid generator (PAG) weight percent, and post-exposure bake (PEB) temperature are varied. Two surprising results are found: (1) changing base weight percent does not significantly affect the deprotection blur of EUV photoresist, and (2) increasing PAG weight percent can simultaneously reduce LER and E-size in EUV …
Date: May 20, 2009
Creator: Anderson, Christopher N.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The LSST camera corner raft conceptual design: a front-end for guiding and wavefront sensing (open access)

The LSST camera corner raft conceptual design: a front-end for guiding and wavefront sensing

None
Date: May 20, 2010
Creator: Arndt, K.; Riot, V.; Alagoz, E.; Biccum, A.; Bohn, A.; Clampit, J. et al.
Object Type: Article
System: The UNT Digital Library
Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors (open access)

Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors

Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors Phase 1 Summary Purpose of the research: The Phase 1 goal was to make a significant improvement in the wire drawing technology used for difficult to draw superconductor precursor composites. Many ductile Nb-Al and Nb-Sn precursor wire composites have experienced the onset of wire drawing breakage at about 1.5 mm diameter. Phase 1 focused on evaluating the role that precision rigid guidance of the wire into the drawing die and the hydrostatic stress state at the die entrance played in preventing wire breakage. Research carried out: The research performed depended upon the construction of both a mechanical wire guide and a hydrostatic pressure stiffened wire guidance system. Innovare constructed the two wire guidance systems and tested them for their ability to reduce wire drawing breakage. One set of hardware provided rigid alignment of the wires to their wire drawing die axes within 0.35 degrees using ''hydrostatic pressure stiffening'' to enable the precision guidance strategy to be implemented for these highly flexible small diameter wires. This apparatus was compared to a guide arrangement that used short span mechanical guide alignment with a misalignment limit of about 0.75 degrees. Four …
Date: May 20, 2003
Creator: Austen, Alfred R.
Object Type: Report
System: The UNT Digital Library
Non-Classical Smoothening of Nano-Scale Surface Corrugations (open access)

Non-Classical Smoothening of Nano-Scale Surface Corrugations

We report the first experimental observation of non-classical morphological equilibration of a corrugated crystalline surface. Periodic rippled structures with wavelengths of 290-550 nm were made on Si(OO1) by sputter rippling and then annealed at 650 - 750 &deg;C. In contrast to the classical exponential decay with time, the ripple amplitude, A<sub>{lambda}</sub>(t), followed an inverse linear decay, A<sub>{lambda}</sub>(t)= A<sub>{lambda}</sub>(0)/(1 +k<sub>{lambda}</sub>t), agreeing with a prediction of Ozdemir and Zangwill. We measure the activation energy for surface relaxation to be 1.6&plusmn;0.2 eV, consistent with an interpretation that dimers mediate transport.
Date: May 20, 1999
Creator: Aziz, Michael J.; Chason, Eric; Erlebacher, Jonah; Floro, Jerrold A. & Sinclair, Michael B.
Object Type: Article
System: The UNT Digital Library
500 CFM portable exhauster temperature and humidity analysis (open access)

500 CFM portable exhauster temperature and humidity analysis

500 cfm portable exhausters will be utilized on single shell tanks involved in saltwell pumping. This will be done, in part, to remove flammable gases from the tank vapor space. The exhaust filter train, fan, stack, and associated instrumentation and equipment are mounted on a portable skid. The design analysis and basis for the skid system design are documented in reference 1. A pumped drainage collection system is being added to the existing portable exhausters. Additional equipment and instrumentation are also being added to the exhausters, including a vacuum pump cabinet and a generic effluent monitoring system (GEMS). The GEMS will provide sampling and monitoring capabilities. The purpose of this analysis is three fold. First, to determine the maximum saltwell tank vapor space temperature. Second, to determine an allowable exhauster inlet air temperature increase to ensure the humidity is less than 70%. Third, to assess potential adverse temperature effects to the continuous air monitor (CAM) sample head. The results of this analysis will be used to ensure that air stream temperatures in the portable exhausters are increased sufficiently to prevent condensation from forming on either the pre or HEPA filters without adversely effecting the CAM.
Date: May 20, 1999
Creator: BIELICKI, B.E.
Object Type: Report
System: The UNT Digital Library
Project management plan for low-level mixed waste and greater-than-category 3 waste per tri-party agreement M-91-10 (open access)

Project management plan for low-level mixed waste and greater-than-category 3 waste per tri-party agreement M-91-10

The objective of this project management plan is to define the tasks and deliverables that will support the treatment, storage, and disposal of remote-handled and large container contact-handled low-level mixed waste, and the storage of Greater-thaw category 3 waste. The plan is submitted to fulfill the requirements of the Hanford Federal Facility Agreement and Consent Order Milestone M-91-10, The plan was developed in four steps: (1) the volumes of the applicable waste streams and the physical, dangerous, and radioactive characteristics were established using existing databases and forecasts; (2) required treatment was identified for each waste stream based on land disposal restriction treatment standards and waste characterization data; (3) alternatives for providing the required treatment were evaluated and the preferred options were selected; (4) an acquisition plan was developed to establish the technical, schedule, and cost baselines for providing the required treatment capabilities. The major waste streams are tabulated, along with the required treatment for disposal.
Date: May 20, 1999
Creator: BOUNINI, L.
Object Type: Report
System: The UNT Digital Library
Performance Technolgies for Peta-Scale Systems: A White Paper Prepared by the Performance Evaluation Research Center (open access)

Performance Technolgies for Peta-Scale Systems: A White Paper Prepared by the Performance Evaluation Research Center

Future-looking high end computing initiatives will deploy powerful, large-scale computing platforms that leverage novel component technologies for superior node performance in advanced system architectures with tens or even hundreds of thousands of nodes. Recent advances in performance tools and modeling methodologies suggest that it is feasible to acquire such systems intelligently and achieve excellent performance, while also significantly reducing the user time required to attain high performance. These developments are relevant to several aspects of future HEC technology outlined in the recent HECRTF white paper request, in particular items 5.4, 5.5, 5.6, and 5.8. We envision the following specific capabilities: (1) Performance modeling tools, available to researchers and vendors, will extrapolate performance from prototype systems to full-scale systems, and even accurately predict performance behavior before systems are manufactured, thus enabling both improved designs and more intelligent selection of systems in procurements. (2) System simulation facilities, implemented on highly parallel platforms and available to researchers and vendors, will for instance realistically model the performance of a specific interprocessor network design running a specific scientific application code. As with item 1, these facilities can lead both to improved designs and procurement decisions that yield significantly greater sustained performance for targeted scientific applications. …
Date: May 20, 2003
Creator: Bailey, D. H.; de Supinski, B. R.; Dongarra, J.; Dunigan, T.; Gao, G.; Hoisie, A. et al.
Object Type: Report
System: The UNT Digital Library
Sampling and analysis plan for sludge located in fuel storage canisters of the 105-K east basin (open access)

Sampling and analysis plan for sludge located in fuel storage canisters of the 105-K east basin

This Sampling and Analysis Plan (SAP) provides direction for the first sampling of sludge from the K East Basin spent fuel canisters. The specially developed sampling equipment used removes representative samples of sludge while maintaining the radioactive sample underwater in the basin pool (equipment is described in WHC-SD-SNF-SDD-004). Included are the basic background logic for sample selection, the overall laboratory analyses required and the laboratory reporting required. These are based on requirements put forth in the data quality objectives (WHC-SD-SNF-DQO-008) established for this sampling and characterization activity.
Date: May 20, 1996
Creator: Baker, R. B.
Object Type: Report
System: The UNT Digital Library
An Online Scheduling Algorithm with Advance Reservation for Large-Scale Data Transfers (open access)

An Online Scheduling Algorithm with Advance Reservation for Large-Scale Data Transfers

Scientific applications and experimental facilities generate massive data sets that need to be transferred to remote collaborating sites for sharing, processing, and long term storage. In order to support increasingly data-intensive science, next generation research networks have been deployed to provide high-speed on-demand data access between collaborating institutions. In this paper, we present a practical model for online data scheduling in which data movement operations are scheduled in advance for end-to-end high performance transfers. In our model, data scheduler interacts with reservation managers and data transfer nodes in order to reserve available bandwidth to guarantee completion of jobs that are accepted and confirmed to satisfy preferred time constraint given by the user. Our methodology improves current systems by allowing researchers and higher level meta-schedulers to use data placement as a service where theycan plan ahead and reserve the scheduler time in advance for their data movement operations. We have implemented our algorithm and examined possible techniques for incorporation into current reservation frameworks. Performance measurements confirm that the proposed algorithm is efficient and scalable.
Date: May 20, 2010
Creator: Balman, Mehmet & Kosar, Tevfik
Object Type: Report
System: The UNT Digital Library
Planning for an Integrated Research Experiment (open access)

Planning for an Integrated Research Experiment

None
Date: May 20, 2000
Creator: Barnard, J. J.; Ahle, L. E.; Bangerter, R. O.; Bieniosek, F. M.; Celata, C. M.; Faltens, A. et al.
Object Type: Article
System: The UNT Digital Library
Position sensitive counter development at the linac (open access)

Position sensitive counter development at the linac

In a novel application of the multiwire proportional counter we have imaged a collimated neutron beam. Although preliminary, the results are of sufficient import to be described here because of the potential wide application of the multiwire proportional counter to Laboratory problems. The counter was operated with a counting gas pressure of 20 Torr; the counting gas was pure C/sub 4/H/sub 10/. The radiator was a /sup 235/U foil. Under these conditions, the counter is (1) relatively insensitive to charged particles (other than fission fragments), (2) insensitive to ..gamma..-radiation, and (3) has an efficiency for the detection of fission fragments independent of incident neutron energy over a wide range of neutron energies.
Date: May 20, 1981
Creator: Becker, J. A.
Object Type: Report
System: The UNT Digital Library
Superconducting RF systems for eRHIC (open access)

Superconducting RF systems for eRHIC

The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.
Date: May 20, 2012
Creator: Belomestnykh, S.; Ben-Zvi, Ilan; Brutus, J. C. & Hahn, H.
Object Type: Article
System: The UNT Digital Library
Multi-jet Cross Sections at NLO with BlackHat and Sherpa (open access)

Multi-jet Cross Sections at NLO with BlackHat and Sherpa

In this talk, we report on a recent next-to-leading order QCD calculation of the production of a W boson in association with three jets at hadron colliders. The computation is performed by combining two programs, BlackHat for the computation of the virtual one-loop matrix elements and Sherpa for the real emission part. The addition of NLO corrections greatly reduces the factorization and renormalization scale dependence of the theory prediction for this process. This result demonstrates the applicability of unitarity-based methods for hadron collider physics.
Date: May 20, 2009
Creator: Berger, C.F.; Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Forde, D.; Gleisberg, T. et al.
Object Type: Article
System: The UNT Digital Library
Left-Handed W bosons at the LHC (open access)

Left-Handed W bosons at the LHC

The production of W bosons in association with jets is an important background to new physics at the LHC. Events in which the W carries large transverse momentum and decays leptonically lead to large missing energy and are of particular importance. We show that the left-handed nature of the W coupling, combined with valence quark domination at a pp machine, leads to a large left-handed polarization for both W{sup +} and W{sup -} bosons at large transverse momenta. The polarization fractions are very stable with respect to QCD corrections. The leptonic decay of the W{sup +-} bosons translates the common left-handed polarization into a strong asymmetry in transverse momentum distributions between positrons and electrons, and between neutrinos and anti-neutrinos (missing transverse energy). Such asymmetries may provide an effective experimental handle on separating W +jets from top quark production, which exhibits very little asymmetry due to C invariance, and from various types of new physics.
Date: May 20, 2011
Creator: Bern, Z.; /UCLA; Diana, G.; /Saclay, SPhT; Dixon, L.J.; /SLAC, /CERN et al.
Object Type: Article
System: The UNT Digital Library
Amplitudes and Ultraviolet Behavior of N = 8 Supergravity (open access)

Amplitudes and Ultraviolet Behavior of N = 8 Supergravity

In this contribution we describe computational tools that permit the evaluation of multi-loop scattering amplitudes in N = 8 supergravity, in terms of amplitudes in N = 4 super-Yang-Mills theory. We also discuss the remarkable ultraviolet behavior of N = 8 supergravity, which follows from these amplitudes, and is as good as that of N = 4 super-Yang-Mills theory through at least four loops.
Date: May 20, 2011
Creator: Bern, Zvi; Carrasco, John Joseph; Dixon, Lance J.; Johansson, Henrik & Roiban, Radu
Object Type: Article
System: The UNT Digital Library
Reduction of the beam breakup mode Q values in the ETA/ATA Accelerating Cells (open access)

Reduction of the beam breakup mode Q values in the ETA/ATA Accelerating Cells

Earlier Microwave Measurements of the ETA Accelerating Cells has uncovered eleven resonances in the frequency range of 0 > 850 MHz. The Q values of these modes ranged from 14 to 70. A three phase program directed at substantially reducing these Q values is reported. In particular the dampening methods described below resulted in a decrease of Q value from 40 to 5 for the beam breakup mode (TM/sub 110/) with a corresponding reduction for most of the other cavity modes.
Date: May 20, 1980
Creator: Birx, D.L.
Object Type: Report
System: The UNT Digital Library