Design of An 18 MW Beam Dump for 500 GeV Electron/Positron Beams at An ILC (open access)

Design of An 18 MW Beam Dump for 500 GeV Electron/Positron Beams at An ILC

This article presents a report on the progress made in designing 18 MW water based Beam Dumps for electrons or positrons for an International Linear Collider (ILC). Multi-dimensional technology issues have to be addressed for the successful design of the Beam Dump. They include calculations of power deposition by the high energy electron/positron beam bunch trains, computational fluid dynamic analysis of turbulent water flow, mechanical design, process flow analysis, hydrogen/oxygen recombiners, handling of radioactive 7Be and 3H, design of auxiliary equipment, provisions for accident scenarios, remote window exchanger, radiation shielding, etc. The progress made to date is summarized, the current status, and also the issues still to be addressed.
Date: July 5, 2012
Creator: Amann, John; /SLAC; Arnold, Ray; /SLAC; Seryi, Andrei; /SLAC et al.
Object Type: Article
System: The UNT Digital Library
Progress on the relativistic klystron two-beam accelerator prototype (open access)

Progress on the relativistic klystron two-beam accelerator prototype

The technical challenge for making two-beam accelerators into realizable power sources lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, l-MeV, electron induction prototype injector as a collaborative effort between LBL and LLNL. The electron source will be a 3.5"-diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 120-ns flat top (1% energy variation), and a normalized edge emittance of less than 200 {pi}-mm-mr. Planned diagnostics include an isolated cathode with resistive divider for direct measurement of current emission, resistive-wall and magnetic probe current monitors for measuring beam current and centroid position, capacitive probes for measuring A-K gap voltage, an energy spectrometer, and a pepper-pot emittance diagnostic. Details of the injector, beam line, and diagnostics are presented.
Date: July 5, 1998
Creator: Anderson, D. E.; Eylon, S.; Henestroza, E.; Houck, T. L.; Lidia, S. M.; Vanecek, D. L. et al.
Object Type: Article
System: The UNT Digital Library
Final Report: Imaging of Buried Nanoscale Optically Active Materials (open access)

Final Report: Imaging of Buried Nanoscale Optically Active Materials

This is a final report covering work done at University of Maryland to develop a Ballistic Electron Emission Luminescence (BEEL) microscope. This technique was intended to examine the carrier transport and photon emission in deeply buried optically-active layers and thereby provide a means for materials science to unmask the detailed consequences of experimentally controllable growth parameters, such as quantum dot size, statistics and orientation, and defect density and charge recombination pathways.
Date: July 5, 2011
Creator: Appelbaum, Ian
Object Type: Report
System: The UNT Digital Library
Measurement of the Spin of the Omega- Hyperon at Babar (open access)

Measurement of the Spin of the Omega- Hyperon at Babar

A measurement of the spin of the {Omega}{sup -} hyperon produced through the exclusive process {Xi}{sub c}{sup 0} {yields} {Omega}{sup -}K{sup +} is presented using a total integrated luminosity of 116 fb{sup -1} recorded with the BABAR detector at the e{sup +}e{sup -} asymmetric-energy B-Factory at SLAC. Under the assumption that the {Xi}{sub c}{sup 0} has spin 1/2, the angular distribution of the {Lambda} from {Omega}{sup -} {yields} {Lambda}K{sup -} decay is inconsistent with all half-integer {Omega}{sup -} spin values other than 3/2. Lower statistics data for the process {Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +} from a 230 fb{sup -1} sample are also found to be consistent with {Omega}{sup -} spin 3/2. If the {Xi}{sub c}{sup 0} spin were 3/2, an {Omega}{sup -} spin of 5/2 cannot be excluded.
Date: July 5, 2006
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
STOCHASTIC COOLING STUDIES IN RHIC, II. (open access)

STOCHASTIC COOLING STUDIES IN RHIC, II.

Intra-beam scattering (IBS) is unavoidable for highly charged heavy ions and causes emittance growth during the store for collision physics. A longitudinal bunched beam stochastic cooling system will confine the bunch within the RF bucket increasing the useful luminosity. We describe a series of measurements in RHIC that have been used to verify our understanding of the relevant physics and the cooling system architecture that is being prototyped.
Date: July 5, 2004
Creator: BLASKIEWICZ,M. BRENNAN,J. M. WEI,J.
Object Type: Article
System: The UNT Digital Library
RF TECHNIQUES FOR IMPROVED LUMINOSITY IN RHIC. (open access)

RF TECHNIQUES FOR IMPROVED LUMINOSITY IN RHIC.

The luminosity of the Relativistic Heavy Ion Collider has improved significantly [1] over the first three physics runs. A number of special rf techniques have been developed to facilitate higher luminosity. The techniques described herein include: an ultra low-noise rf source for the 197 MHz storage rf system, a frequency shift switch-on technique for transferring bunches from the acceleration to the storage system, synchronizing the rings during the energy ramp (including crossing the transition energy) to avoid incidental collisions, installation of dedicated 200 MHZ cavities to provide longitudinal Landau damping on the ramp, and the development of a bunch merging scheme in the Booster to increase the available bunch intensity from the injectors.
Date: July 5, 2004
Creator: BRENNAN,J. M. BLASKIEWICZ,J. BUTLER,J. DELONG,J. FISCHER,W. HAYES,T.
Object Type: Article
System: The UNT Digital Library
RESULTS OF THE NASA SPACE RADIATION LABORATORY BEAM STUDIES PROGRAM AT BNL. (open access)

RESULTS OF THE NASA SPACE RADIATION LABORATORY BEAM STUDIES PROGRAM AT BNL.

The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. The purpose of the NSRL Beam Studies Program is to develop a clear understanding of the beams delivered to the facility, to fully characterize those beams, and to develop new capabilities in the interest of understanding the radiation environment in space. In this report we will describe the first results from this program.
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BEUTTENMULLER,R. H. ET AL.
Object Type: Article
System: The UNT Digital Library
RESULTS OF THE FIRST RUN OF THE NASA SPACE RADIATION LABORATORY AT BNL. (open access)

RESULTS OF THE FIRST RUN OF THE NASA SPACE RADIATION LABORATORY AT BNL.

The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The results of commissioning of this new facility were reported in [l]. In this report we will describe the results of the first run. The NSRL is capable of making use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. Many modes of operation were explored during the first run, demonstrating all the capabilities designed into the system. Heavy ion intensities from 100 particles per pulse up to 12 x 10{sup 9} particles per pulse were delivered to a large variety of experiments, providing a dose range up to 70 Gy/min over a 5 x 5 cm{sup 2} area. Results presented will include those related to the production of beams that are highly uniform in both the transverse and longitudinal planes of motion [2].
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BRENNAN,J. M. ET. AL.
Object Type: Article
System: The UNT Digital Library
MINI-BUNCHED AND MICRO-BUNCHED SLOW EXTRACTED BEAMS FROM THE AGS. (open access)

MINI-BUNCHED AND MICRO-BUNCHED SLOW EXTRACTED BEAMS FROM THE AGS.

Brookhaven National Laboratory's (BNLs) Alternating Gradient Synchrotron (AGS) has a long history of providing slow extracted proton beams to fixed target experiments. This program of providing high quality high intensity beams continues with two new experiments currently being designed for operation at the AGS. Both experiments require slow extracted beam, but with an added requirement that those beams be bunched. Bunched beam slow extraction techniques have been developed for both experiments and initial tests have been performed. In this report we describe the beam requirements for the two experiments, and present results of detailed simulations and initial beam tests.
Date: July 5, 2004
Creator: BROWN,K. A. AHRENS,L. BRENNAN,J. M. GLENN,J. W. SIVERTZ,M. KOSCIELNIAK,S. R.
Object Type: Article
System: The UNT Digital Library
The Case for a 500 GeV e+e- Linear Collider (open access)

The Case for a 500 GeV e+e- Linear Collider

Several proposals are being developed around the world for an e+e- linear collider with an initial center of mass energy of 500 GeV. In this paper, we will discuss why a project of this type deserves priority as the next major initiative in high energy physics.
Date: July 5, 2000
Creator: Baggers, J.; Baltay, C.; Barker, T.; Barklow, T.; Bauer, U.; Bolton, T. et al.
Object Type: Report
System: The UNT Digital Library
Non-Destructive Beam Measurements (open access)

Non-Destructive Beam Measurements

In high energy accelerators, especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is an ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with a Schottky detector, phase advance measurements as well as nonlinear resonance measurements with the ac dipoles in the Brookhaven RHIC.
Date: July 5, 2004
Creator: Bai, M.
Object Type: Article
System: The UNT Digital Library
Effect of increased electric loads on primary substation equipment in 100-B, C, D, DR, F, and H areas (open access)

Effect of increased electric loads on primary substation equipment in 100-B, C, D, DR, F, and H areas

The loading on the primary transformers which step down the 230 kv transmission voltage to a distribution voltage of 13.8 kv, at 100-B-C, 100-D-DR, 100-F, and 100-H Areas will be increased by the synchronous motors now being installed in those areas under Project CG-558. This report summarizes: The changes in electric loads (both kv and power factor) which will result when the new motors are placed in service and certain older motors are withdrawn from service. Electric loads are tabulated in section 4.0 for each area for present conditions, the planned changes and the post-CG-558 conditions. The reduction of distribution voltage during the starting of individual 4500 hp synchronous motors. Since the synchronous motors will be started across the line as induction motors, the starting current will be high, and at a low power factor. Voltage drops are calculated for the starting of a synchronous motor, with one and then with two transformer banks paralleled. The current-interrupting capacity of switchgear vs. the maximum short-circuit current which could occur with separate transformers and with two primary transformers in parallel.
Date: July 5, 1956
Creator: Baker, D. S. & McLenegan, D. W.
Object Type: Report
System: The UNT Digital Library
In-Home Performance of Exempt Pellet Stoves in Medford, Oregon. (open access)

In-Home Performance of Exempt Pellet Stoves in Medford, Oregon.

Pellet stoves that are considered exempt'' operate at an air-to-fuel ratio in excess of 35:1. They therefore qualify for exemption from the emissions certification process. A primary goal of this project was to determine how a sample of such stoves, operated in homes, would perform compared to their certified cousins,'' which were evaluated the previous year. In-home performance data documenting emissions from exempt stoves and net delivered efficiencies was particularly desired. This project evaluated six pellet stoves representing three major brands in Medford, Oregon. There were three Breckwell model P24FS, one Horizon Eclipse, one Horizon Destiny, and one Earth Stove TP40. The stoves were monitored for four week-long intervals in January and February 1991, for a total of 24 tests. Evaluations were conducted for particulate, CO (carbon monoxide) and PAH (polycyclic aromatic hydrocarbon) emissions and net efficiency. Monitoring was conducted using the AWES (automated woodstove emissions sampler) sampling system. A new data logger, developed for this project, was used to control the AWES and record real time data. 22 refs., 17 figs., 6 tabs.
Date: July 5, 1991
Creator: Barnett, Stockton G. & Fields, Paula G.
Object Type: Report
System: The UNT Digital Library
All One-loop Maximally Helicity Violating Gluonic Amplitudes in QCD (open access)

All One-loop Maximally Helicity Violating Gluonic Amplitudes in QCD

We use on-shell recursion relations to compute analytically the one-loop corrections to maximally-helicity-violating n-gluon amplitudes in QCD. The cut-containing parts have been computed previously; our work supplies the remaining rational parts for these amplitudes, which contain two gluons of negative helicity and the rest positive, in an arbitrary color ordering. We also present formulae specific to the six-gluon cases, with helicities (-+-+++) and (-++-++), as well as numerical results for six, seven, and eight gluons. Our construction of the n-gluon amplitudes illustrates the relatively modest growth in complexity of the on-shell-recursive calculation as the number of external legs increases. These amplitudes add to the growing body of one-loop amplitudes known for all n, which are useful for studies of general properties of amplitudes, including their twistor-space structure.
Date: July 5, 2006
Creator: Berger, Carola F.; Bern, Zvi; Dixon, Lance J.; Forde, Darren & Kosower, David A.
Object Type: Report
System: The UNT Digital Library
Studies on Large Area Sub-Fabric Burns (open access)

Studies on Large Area Sub-Fabric Burns

The detonation of shot one at Bikini Atoll on March 1, 1954, produced a fallout of radioactive ash upon Rongelap Atoll, Marshall Islands. The distribution of the radioactive ash on the islands and in the plants and animals of the area has been studied and evaluated. During the first expedition to Rongelap Atoll on March 26, 1954, biological samples were collected and measurements made of the radiation contamination. On three additional expeditions extensive collections of material were made for this study, the last on January 25-30, 1955. The decline in radioactivity was measured in 1499 samples of fish, invertebrates, land plants, algae, birds, plankton, soil, and water from the Rongelap area. During this study particular emphasis was placed upon evaluation of the radioactivity in food used by the natives. Coconut milk collected on March 26, 1954, contained 1.03 microcuries per kilogram of wet tissue while the coconut meat had 1.16 mu c/kg. By January 25-30, 1955, the level in coconut milk had declined to 0.041 mu c/kg and the meat to 0.036 mu c/ kg. Fish muscle on March 26, 1954, averaged 2.74 mu c/kg and fish liver 204.0 mu c/kg. The decline to January 25-30 was 0.10 mu c/kg …
Date: July 5, 1957
Creator: Berkley, K. M. & Pearse, H. E.
Object Type: Report
System: The UNT Digital Library
Simulation of the fundamental and nonlinear harmonic output from an FEL amplifier with a soft x-ray seed laser (open access)

Simulation of the fundamental and nonlinear harmonic output from an FEL amplifier with a soft x-ray seed laser

A single-pass, high-gain free-electron laser (FEL) x-ray amplifier was simulated using the 3D, polychromatic simulation code MEDUSA. The seed for the system is a table-top, soft x-ray laser. The simulated fundamental and nonlinear harmonic x-ray output wavelengths are discussed.
Date: July 5, 2000
Creator: Biedron, S. G.; Freund, H. P.; Li, Y. & Milton, S. V.
Object Type: Article
System: The UNT Digital Library
Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000 (open access)

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000

Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2000 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.
Date: July 5, 2001
Creator: Bivins, Steven R & Stoetzel, Gregory A
Object Type: Report
System: The UNT Digital Library
Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000 (open access)

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000

Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually, and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2000 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.
Date: July 5, 2001
Creator: Bivins, Steven R. & Stoetzel, Gregory A.
Object Type: Report
System: The UNT Digital Library
Final Technical Report - In-line Uranium Immunosensor (open access)

Final Technical Report - In-line Uranium Immunosensor

In this project, personnel at Tulane University and Sapidyne Instruments Inc. developed an in-line uranium immunosensor that could be used to determine the efficacy of specific in situ biostimulation approaches. This sensor was designed to operate autonomously over relatively long periods of time (2-10 days) and was able to provide near real-time data about uranium immobilization in the absence of personnel at the site of the biostimulation experiments. An alpha prototype of the in-line immmunosensor was delivered from Sapidyne Instruments to Tulane University in December of 2002 and a beta prototype was delivered in November of 2003. The beta prototype of this instrument (now available commercially from Sapidyne Instruments) was programmed to autonomously dilute standard uranium to final concentrations of 2.5 to 100 nM (0.6 to 24 ppb) in buffer containing a fluorescently labeled anti-uranium antibody and the uranium chelator, 2,9-dicarboxyl-1,10-phenanthroline. The assay limit of detection for hexavalent uranium was 5.8 nM or 1.38 ppb. This limit of detection is well below the drinking water standard of 30 ppb recently promulgated by the EPA. The assay showed excellent precision; the coefficients of variation (CV’s) in the linear range of the assay were less than 5% and CV’s never rose above …
Date: July 5, 2006
Creator: Blake, Diane A.
Object Type: Report
System: The UNT Digital Library
High Brightness Electron Guns for Next-Generation Light Sources and Accelerators. (open access)

High Brightness Electron Guns for Next-Generation Light Sources and Accelerators.

Next-generation light sources and accelerators are being proposed that set unique requirements for the electron source parameters. No single source is suitable for the diverse applications, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with our various partners, is developing a variety of electron gun concepts for these important applications.
Date: July 5, 2004
Creator: Bluem, H. P.; Ben-Zvi, Ilan; Srinivasan-Rao, T. & AL., ET
Object Type: Article
System: The UNT Digital Library
The Injection System of the INFN-SuperB Factory Project: Preliminary Design (open access)

The Injection System of the INFN-SuperB Factory Project: Preliminary Design

The ultra high luminosity B-factory (SuperB) project of INFN requires a high performance and reliable injection system, providing electrons at 4 GeV and positrons at 7 GeV, to fulfil the very tight requirements of the collider. Due to the short beam lifetime, continuous injection of electron and positron bunches in both LER and HER rings is necessary to maintain an high average luminosity. Polarized electrons are required for experiments and must be delivered by the injection system, due to the beam lifetime shorter than the ring polarization build-up: they will be produced by means of a SLAC-SLC polarized gun. The emittance and the energy spread of the e{sup -}/e{sup +} beams are reduced in a 1 GeV Damping Ring (DR) before injection in the main rings. Two schemes for positron production are under study, one with e{sup -}/e{sup +} conversion at low energy (< 1 Gev) and one with conversion at 6 GeV and a recirculation line to bring the positrons back to the DR. Acceleration through the Linac is provided by a 2856 MHz RF system made of travelling wave (TW), room temperature accelerating structures.
Date: July 5, 2012
Creator: Boni, Roberto; Guiducci, Susanna; Preger, Miro; Raimondi, Pantaleo; Chance, Antoine; Dadoun, Olivier et al.
Object Type: Article
System: The UNT Digital Library
Control of Toxic Chemicals in Puget Sound, Phase 3: Study of Atmospheric Deposition of Air Toxics to the Surface of Puget Sound (open access)

Control of Toxic Chemicals in Puget Sound, Phase 3: Study of Atmospheric Deposition of Air Toxics to the Surface of Puget Sound

The results of the Phase 1 Toxics Loading study suggested that runoff from the land surface and atmospheric deposition directly to marine waters have resulted in considerable loads of contaminants to Puget Sound (Hart Crowser et al. 2007). The limited data available for atmospheric deposition fluxes throughout Puget Sound was recognized as a significant data gap. Therefore, this study provided more recent or first reported atmospheric deposition fluxes of PAHs, PBDEs, and select trace elements for Puget Sound. Samples representing bulk atmospheric deposition were collected during 2008 and 2009 at seven stations around Puget Sound spanning from Padilla Bay south to Nisqually River including Hood Canal and the Straits of Juan de Fuca. Revised annual loading estimates for atmospheric deposition to the waters of Puget Sound were calculated for each of the toxics and demonstrated an overall decrease in the atmospheric loading estimates except for polybrominated diphenyl ethers (PBDEs) and total mercury (THg). The median atmospheric deposition flux of total PBDE (7.0 ng/m2/d) was higher than that of the Hart Crowser (2007) Phase 1 estimate (2.0 ng/m2/d). The THg was not significantly different from the original estimates. The median atmospheric deposition flux for pyrogenic PAHs (34.2 ng/m2/d; without TCB) shows …
Date: July 5, 2010
Creator: Brandenberger, Jill M.; Louchouarn, Patrick; Kuo, Li-Jung; Crecelius, Eric A.; Cullinan, Valerie I.; Gill, Gary A. et al.
Object Type: Report
System: The UNT Digital Library
Atomistic Modeling of Wave Propagation in Nanocrystals (open access)

Atomistic Modeling of Wave Propagation in Nanocrystals

We present non-equilibrium molecular dynamics (MD) simulations of wave propagation in nanocrystals. We find that the width of the traveling wave front increases with grain size, d, as d{sup 1/2}. This width also decreases with the pressure behind the front. We extrapolate our results to micro-crystals and obtain reasonable agreement with experimental data. In addition, our extrapolation agrees with models that only take into account the various velocities of propagation along different crystalline orientations, without including grain boundary effects. Our results indicate that, even at the nanoscale, the role of grain boundaries as scattering centers or as sources of plasticity does not increase significantly the width of the traveling wave.
Date: July 5, 2005
Creator: Bringa, E; Caro, A; Victoria, M & Park, N
Object Type: Article
System: The UNT Digital Library
Growth of large patterned arrays of neurons using plasma methods (open access)

Growth of large patterned arrays of neurons using plasma methods

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Date: July 5, 2002
Creator: Brown, I. G.; Bjornstad, K. A.; Blakely, E. A.; Galvin, J. E.; Monteiro, O. R. & Sangyuenyongpipat, S.
Object Type: Article
System: The UNT Digital Library