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
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
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
Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study (open access)

Characterization of fundamental catalytic properties of MoS2/WS2 nanotubes and nanoclusters for desulfurization catalysis - a surface temperature study

The prior project consisted of two main project lines. First, characterization of novel nanomaterials for hydrodesulfurization (HDS) applications. Second, studying more traditional model systems for HDS such as vapor-deposited silica-supported Mo and MoSx clusters. In the first subproject, we studied WS2 and MoS2 fullerene-like nanoparticles as well as WS2 nanotubes. Thiophene (C4H4S) was used as the probe molecule. Interestingly, metallic and sulfur-like adsorption sites could be identified on the silica-supported fullerene-particles system. Similar structures are seen for the traditional system (vapor-deposited clusters). Thus, this may be a kinetics fingerprint feature of modern HDS model systems. In addition, kinetics data allowed characterization of the different adsorption sites for thiophene on and inside WS2 nanotube bundles. The latter is a unique feature of nanotubes that has not been reported before for any inorganic nanotube system; however, examples are known for carbon nanotubes, including prior work of the PI. Although HDS has been studied for decades, utilizing nanotubes as nanosized HDS reactors has never been tried before, as far as we know. This is of interest from a fundamental perspective. Unfortunately, the HDS activity of the nanocatalysts at ultra-high vacuum (UHV) conditions was close to the detection limit of our techniques. Therefore, we …
Date: July 5, 2012
Creator: Burghaus, U.
Object Type: Report
System: The UNT Digital Library
Linac Energy Management for LCLS (open access)

Linac Energy Management for LCLS

Linac Energy Management (LEM) is a control system program that scales magnet field set-point settings following a change in beam energy. LEM is necessary because changes in the number, phase, and amplitude of the active klystrons change the beam's rigidity, and therefore, to maintain constant optics, one has to change focusing gradients and bend fields accordingly. This paper describes the basic process, the control system application programs we developed for LEM, and some of the implementation lessons learned at the Linac Coherent Light Source (LCLS).
Date: July 5, 2012
Creator: Chu, Chungming; Iverson, Richard; Krejcik, Patrick; Rogind, Deborah; White, Greg & Woodley, Mark
Object Type: Article
System: The UNT Digital Library
Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II (open access)

Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II

The vertical emittance of the low energy ring (LER) in the PEP-II B-Factory was reduced by using skew quadrupoles consisting of permanent magnet material. The advantages over electric quadrupoles or rotating existing normal quadrupoles are discussed. To assure a high field quality, a Biot-Savart calculation was used to cancel the natural 12-pole component by using different size poles over a few layers. A magnetic measurement confirmed the high quality of the magnets. After installation and adjusting the original electric 12 skew and 16 normal quadrupoles the emittance contribution from the region close to the interaction point, which was the biggest part in the original design, was considerably reduced. To strengthen the vertical behavior of the LER beam, a low emittance lattice was developed. It lowered the original vertical design emittance from 0.54 nm-rad to 0.034 nm-rad. In order to achieve this, additional skew quadrupoles were required to bring the coupling correction out of the arcs and closer to the detector solenoid in the straight (Fig. 1). It is important, together with low vertical dispersion, that the low vertical emittance is not coupled into the horizontal, which is what we get if the coupling correction continues into the arcs. Further details …
Date: July 5, 2011
Creator: Decker, F. -J.; Anderson, S.; Kharakh, D. & Sullivan, M.
Object Type: Article
System: The UNT Digital Library
Full multiple scattering analysis of XANES at the Cd L3 and O K edges in CdO films combined with a soft-x-ray emission investigation (open access)

Full multiple scattering analysis of XANES at the Cd L3 and O K edges in CdO films combined with a soft-x-ray emission investigation

X-ray absorption near edge structure (XANES) at the cadmium L3 and oxygen K edges for CdO thin films grown by pulsed laser deposition method, is interpreted within the real-space multiple scattering formalism, FEFF code. The features in the experimental spectra are well reproduced by calculations for a cluster of about six and ten coordination shells around the absorber for L3 edge of Cd and K edge of O, respectively. The calculated projected electronic density of states is found to be in good agreement with unoccupied electronic states in experimental data and allows to conclude that the orbital character of the lowest energy of the conductive band is Cd-5s-O-2p. The charge transfer has been quantified and not purely ionic bonding has been found. Combined XANES and resonant inelastic x-ray scattering measurements allow us to determine the direct and indirect band gap of investigated CdO films to be {approx}2.4-eV and {approx}0.9-eV, respectively.
Date: July 5, 2010
Creator: Demchenko, I. N.; Denlinger, J. D.; Chernyshova, M.; Yu, K. M.; Speaks, D. T.; Olalde-Velasco, P. et al.
Object Type: Article
System: The UNT Digital Library
Qualification of the First ICS-3000 ION Chromatograph for use at the Defense Waste Processing Facility (open access)

Qualification of the First ICS-3000 ION Chromatograph for use at the Defense Waste Processing Facility

The ICS-3000 Ion Chromatography (IC) system installed in 221-S M-13 has been qualified for use. The qualification was a head to head comparison of the ICS-3000 with the currently used DX-500 IC system. The crosscheck work included standards for instrument calibration and calibration verifications and standards for individual anion analysis, where the standards were traceable back to the National Institute of Standards and Technology (NIST). In addition the crosscheck work included the analysis of simulated Sludge Receipt Adjustment Tank (SRAT) Receipt, SRAT Product, and Slurry Mix Evaporator (SME) samples, along with radioactive Sludge Batch 5 material from the SRAT and SME tanks. Based upon the successful qualification of the ICS-3000 in M-13, it is recommended that this task proceed in developing the data to qualify, by a head to head comparison of the two ICS-3000 instruments, a second ICS-3000 to be installed in M-14. The Defense Waste Processing Facility (DWPF) requires the analysis of specific anions at various stages of its processing of high level waste (HLW). The anions of interest to the DWPF are fluoride, formate, chloride, nitrite, nitrate, sulfate, oxalate, and phosphate. The anion analysis is used to evaluate process chemistry including formic acid/nitric acid additions to establish …
Date: July 5, 2011
Creator: Edwards, T & Mahannah, R.
Object Type: Report
System: The UNT Digital Library
Qualification of a Carbon Analyzer to Support the Defense Waste Processing Facility (open access)

Qualification of a Carbon Analyzer to Support the Defense Waste Processing Facility

The I-O Model 1030 carbon analyzer has been qualified for use at the Defense Waste Processing Facility (DWPF). The qualification was a side-by-side comparison of the Model 1030 system with the currently used Model 1010 Analyzer. This recommendation is based on side-by-side comparisons of the new unit to the currently used Model 1010 analyzer that are presented in this report. The side-by-side testing included standards and process samples. The standards, which were used for instrument calibration verifications in the measurement of total inorganic carbon (TIC) and of total organic carbon (TOC), were traceable back to the National Institute of Standards and Technology. The process samples included TIC analyses of Sludge Receipt and Adjustment Tank samples and TOC analyses for Slurry Mix Evaporator (SME) samples. After the Model 1030 has been used for production reporting, DWPF should consider an investigation into the uncertainties associated with the TOC measurements to determine how far below the 18,916 ppm limit DWPF must control the average of the measurements for a set of SME samples to account for the uncertainties of the measurements from this new analyzer. Based upon the results presented in this report, it is recommended that the Model 1030 carbon analyzer is …
Date: July 5, 2011
Creator: Edwards, T. & Feller, M.
Object Type: Report
System: The UNT Digital Library
Qualification of the Nippon Instrumentation for use in Measuring Mercury at the Defense Waste Processing Facility (open access)

Qualification of the Nippon Instrumentation for use in Measuring Mercury at the Defense Waste Processing Facility

The Nippon Mercury/RA-3000 system installed in 221-S M-14 has been qualified for use. The qualification was a side-by-side comparison of the Nippon Mercury/RA-3000 system with the currently used Bacharach Mercury Analyzer. The side-by-side testing included standards for instrument calibration verifications, spiked samples and unspiked samples. The standards were traceable back to the National Institute of Standards and Technology (NIST). The side-by-side work included the analysis of Sludge Receipt and Adjustment Tank (SRAT) Receipt, SRAT Product, and Slurry Mix Evaporator (SME) samples. With the qualification of the Nippon Mercury/RA-3000 system in M-14, the DWPF lab will be able to perform a head to head comparison of a second Nippon Mercury/RA-3000 system once the system is installed. The Defense Waste Processing Facility (DWPF) analyzes receipt and product samples from the Sludge Receipt and Adjustment Tank (SRAT) to determine the mercury (Hg) concentration in the sludge slurry. The SRAT receipt is typically sampled and analyzed for the first ten SRAT batches of a new sludge batch to obtain an average Hg concentration. This average Hg concentration is then used to determine the amount of steam stripping required during the concentration/reflux step of the SRAT cycle to achieve a less than 0.6 wt% Hg …
Date: July 5, 2011
Creator: Edwards, T. & Mahannah, R.
Object Type: Report
System: The UNT Digital Library
Ramp-Compression Experiments on Tantalum at the NIF and Omega Lasers (open access)

Ramp-Compression Experiments on Tantalum at the NIF and Omega Lasers

None
Date: July 5, 2011
Creator: Eggert, J H
Object Type: Article
System: The UNT Digital Library
Model-based corrections to observed back azimuth and slowness observations from a dipping Mohorovicic discontinuity (open access)

Model-based corrections to observed back azimuth and slowness observations from a dipping Mohorovicic discontinuity

None
Date: July 5, 2012
Creator: Flanagan, M P; Myers, S C & Simmons, N A
Object Type: Article
System: The UNT Digital Library
Toward an Empirically-based Parametric Explosion Spectral Model (open access)

Toward an Empirically-based Parametric Explosion Spectral Model

None
Date: July 5, 2011
Creator: Ford, S. R.; Walter, W. R.; Ruppert, S. D.; Matzel, E. M.; Hauk, T. F. & Gok, M. R.
Object Type: Article
System: The UNT Digital Library
Radiation Measurements of the Effluent from the NRX-A6 Reactor (open access)

Radiation Measurements of the Effluent from the NRX-A6 Reactor

None
Date: July 5, 2013
Creator: Fultyn, Robert V.
Object Type: Report
System: The UNT Digital Library
Lithospheric Models of the Middle East to Improve Seismic Source Parameter Determination/Event Location Accuracy (open access)

Lithospheric Models of the Middle East to Improve Seismic Source Parameter Determination/Event Location Accuracy

None
Date: July 5, 2012
Creator: Gok, R.; Herzog, S.; Nakanishi, K.; Pasyanos, M.; Mellors, R.; Rodgers, A. et al.
Object Type: Article
System: The UNT Digital Library
International Cooperation of Seismology for Support to the CTBT (open access)

International Cooperation of Seismology for Support to the CTBT

None
Date: July 5, 2011
Creator: Gok, R.; Nakanishi, K. K.; Pasyanos, M. E.; Rodgers, A. J.; Harris, D. B.; Vergino, E. et al.
Object Type: Article
System: The UNT Digital Library
Development of High Average Power Lasers for the Photon Collider (open access)

Development of High Average Power Lasers for the Photon Collider

The laser and optics system for the photon collider seeks to minimize the required laser power by using an optical stacking cavity to recirculate the laser light. An enhancement of between 300 to 400 is desired. In order to achieve this the laser pulses which drive the cavity must precisely match the phase of the pulse circulating within the cavity. We report on simulations of the performance of a stacking cavity to various variations of the drive laser in order to specify the required tolerances of the laser system.
Date: July 5, 2012
Creator: Gronberg, Jeff; /LLNL, Livermore; Stuart, Brent; /LLNL, Livermore; Seryi, Andrei & /SLAC
Object Type: Article
System: The UNT Digital Library
Advances in X-Band TW Accelerator Structures Operating in the 100 MV/M Regime (open access)

Advances in X-Band TW Accelerator Structures Operating in the 100 MV/M Regime

A CERN-SLAC-KEK collaboration on high gradient X-band accelerator structure development for CLIC has been ongoing for three years. The major outcome has been the demonstration of stable 100 MV/m gradient operation of a number of CLIC prototype structures. These structures were fabricated using the technology developed from 1994 to 2004 for the GLC/NLC linear collider initiative. One of the goals has been to refine the essential parameters and fabrication procedures needed to realize such a high gradient routinely. Another goal has been to develop structures with stronger dipole mode damping than those for GLC/NLC. The latter requires that the surface temperature rise during the pulse be higher, which may increase the breakdown rate. One structure with heavy damping has been RF processed and another is nearly finished. The breakdown rates of these structures were found to be higher by two orders of magnitude compared to those with equivalent acceleration mode parameters but without the damping features. This paper presents these results together with some of the earlier results from non-damped structures.
Date: July 5, 2012
Creator: Higo, Toshiyasu; Higashi, Yasuo; Matsumoto, Shuji; Yokoyama, Kazue; Adolphsen, Chris; Dolgashev, Valery et al.
Object Type: Article
System: The UNT Digital Library
Foreign Travel Trip Report for LLNL travel with DOE FES funding,May 19th-30th, 2012 (open access)

Foreign Travel Trip Report for LLNL travel with DOE FES funding,May 19th-30th, 2012

I attended the 20th biannual International Conference on Plasma Surface Interaction (PSI) in Fusion Devices in Aachen, Germany, hosted this year by the Forschungszentrum Julich (FZJ) research center. The PSI conference is one of the main international forums for the presentation and discussion of results on plasma surface interactions and edge plasma physics relevant to magnetic confinement fusion devices. I disseminated the recent results of FESP/LLNL tokamak research by presenting three posters on: (i) understanding reconnection and controlling edge localized modes (ELMs) using the BOUT++ code, (ii) simulation of resistive ballooning mode turbulence, and (iii) innovative design of Snowflake divertors. I learned of many new and recent results from international tokamak facilities and had the opportunity for discussion of these topics with other scientists at the poster sessions, conference lunches/receptions, etc. Some of the major highlights of the PSI conference topics were: (1) Review of the progress in using metallic tungsten and beryllium (ITER-like) walls at international tokamak facilities: JET (Culham, UK), TEXTOR (FZJ, Germany) and Alcator CMOD (MIT, USA). Results included: effect of small and large-area melting on plasma impurity content and recovery, expected reduction in retention of hydrogenic species, increased heat load during disruptions and need for mitigation …
Date: July 5, 2012
Creator: Joseph, I
Object Type: Report
System: The UNT Digital Library
A user's guide to the PLTEMP/ANL code. (open access)

A user's guide to the PLTEMP/ANL code.

PLTEMP/ANL V4.1 is a FORTRAN program that obtains a steady-state flow and temperature solution for a nuclear reactor core, or for a single fuel assembly. It is based on an evolutionary sequence of ''PLTEMP'' codes in use at ANL for the past 20 years. Fueled and non-fueled regions are modeled. Each fuel assembly consists of one or more plates or tubes separated by coolant channels. The fuel plates may have one to five layers of different materials, each with heat generation. The width of a fuel plate may be divided into multiple longitudinal stripes, each with its own axial power shape. The temperature solution is effectively 2-dimensional. It begins with a one-dimensional solution across all coolant channels and fuel plates/tubes within a given fuel assembly, at the entrance to the assembly. The temperature solution is repeated for each axial node along the length of the fuel assembly. The geometry may be either slab or radial, corresponding to fuel assemblies made of a series of flat (or slightly curved) plates, or of nested tubes. A variety of thermal-hydraulic correlations are available with which to determine safety margins such as Onset-of-Nucleate boiling (ONB), departure from nucleate boiling (DNB), and onset of flow …
Date: July 5, 2011
Creator: Kalimullah, M. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
JET MIXING ANALYSIS FOR SRS HIGH-LEVEL WASTE RECOVERY (open access)

JET MIXING ANALYSIS FOR SRS HIGH-LEVEL WASTE RECOVERY

The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank to ensure uniformity of the discharge stream. Mixing is accomplished with one to four slurry pumps located within the tank liquid. The slurry pump may be fixed in position or they may rotate depending on the specific mixing requirements. The high-level waste in Tank 48 contains insoluble solids in the form of potassium tetraphenyl borate compounds (KTPB), monosodium titanate (MST), and sludge. Tank 48 is equipped with 4 slurry pumps, which are intended to suspend the insoluble solids prior to transfer of the waste to the Fluidized Bed Steam Reformer (FBSR) process. The FBSR process is being designed for a normal feed of 3.05 wt% insoluble solids. A chemical characterization study has shown the insoluble solids concentration is approximately 3.05 wt% when well-mixed. The project is requesting a Computational Fluid Dynamics (CFD) mixing study from SRNL to determine the solids behavior with 2, 3, and 4 slurry pumps in operation and an estimate of the insoluble solids concentration at the suction of the transfer pump to the FBSR process. The impact of cooling coils is not considered …
Date: July 5, 2011
Creator: Lee, S.
Object Type: Article
System: The UNT Digital Library
Overview of the Physics and Engineering Design of NSTX Upgrade. (open access)

Overview of the Physics and Engineering Design of NSTX Upgrade.

None
Date: July 5, 2011
Creator: Menard, J. E.; Canik, J.; Chrzanowski, J.; Denault, M.; Dudek, L.; Gerhardt, S. et al.
Object Type: Article
System: The UNT Digital Library
A Superconducting Magnet Upgrade of the ATF2 Final Focus (open access)

A Superconducting Magnet Upgrade of the ATF2 Final Focus

The ATF2 facility at KEK is a proving ground for linear collider technology with a well instrumented extracted beam line and Final Focus (FF). The primary ATF2 goal is to demonstrate the extreme beam demagnification and spot stability needed for a linear collider FF. But the ATF2 FF uses water cooled magnets and the ILC baseline has a superconducting (SC) FF. We plan to upgrade ATF2 and replace some of the warm FF magnets with SC FF magnets. The ATF2 SC magnets, like the ILC FF, will made via direct wind construction. ATF2 coil winding is in progress at BNL and warm magnetic measurements indicate we have achieved good field quality. Studies indicate that having ATF2 FF magnets with larger aperture and better field quality should allow reducing the ATF2 FF beta function for study of focusing regimes relevant to CLIC. The ATF2 magnet cryostat will have laser view ports for directly monitoring cold mass movement. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet performance to that of a full length ILC QD0 R&D FF prototype under construction at BNL.
Date: July 5, 2012
Creator: Parker, Brett; /Brookhaven; Anerella, Michael; /Brookhaven; Escallier, John; /Brookhaven et al.
Object Type: Article
System: The UNT Digital Library