ARM Climate Research Facility Monthly Instrument Report June 2010 (open access)

ARM Climate Research Facility Monthly Instrument Report June 2010

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: July 13, 2010
Creator: Voyles, J. W.
Object Type: Report
System: The UNT Digital Library
Summary of the Preliminary Analysis of Savannah River Depleted Uranium Trioxide (open access)

Summary of the Preliminary Analysis of Savannah River Depleted Uranium Trioxide

This report summarizes a preliminary special analysis of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 2). The analysis is considered preliminary because a final waste profile has not been submitted for review. The special analysis is performed to determine the acceptability of the waste stream for shallow land burial at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The Savannah River Depleted Uranium Trioxide waste stream requires a special analysis because the waste stream’s sum of fractions exceeds one. The 99Tc activity concentration is 98 percent of the NNSS Waste Acceptance Criteria and the largest single contributor to the sum of fractions.
Date: October 13, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Model for Initiation of Quality Factor Degradation at High Accelerating Fields in Superconducting Radio-Frequency Cavaties (open access)

Model for Initiation of Quality Factor Degradation at High Accelerating Fields in Superconducting Radio-Frequency Cavaties

A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Since magnetic fields at the cavity equator are tied to accelerating electric fields by a simple geometric factor, the onset of magnetic flux penetration determines the onset of Q-drop. We consider breakdown of the surface barrier at triangular grooves to predict the magnetic field of first flux penetration H{sub pen}. Such defects were argued to be the worst case by Buzdin and Daumens, [1998 Physica C 294 257], whose approach, moreover, incorporates both the geometry of the groove and local contamination via the Ginzburg-Landau parameter {kappa}. Since previous Q-drop models focused on either topography or contamination alone, the proposed model allows new comparisons of one effect in relation to the other. The model predicts equivalent reduction of H{sub pen} when either roughness or contamination were varied alone, so smooth but dirty surfaces limit cavity performance about as much as rough but clean surfaces do. Still lower H{sub pen} was predicted when both effects were combined, i.e. contamination should exacerbate the negative effects of roughness and vice-versa. To test the model with actual data, coupons were prepared by …
Date: July 13, 2010
Creator: Dzyuba, A.; U., /Fermilab /Novosibirsk State; Romanenko, A.; /Fermilab & Cooley, L. D.
Object Type: Article
System: The UNT Digital Library
Nevada Test Site Environmental Report Summary 2009 (open access)

Nevada Test Site Environmental Report Summary 2009

The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) directs the management and operation of the Nevada Test Site (NTS). NNSA/NSO prepares the Nevada Test Site Environmental Report (NTSER) to provide the public an understanding of the environmental monitoring and compliance activities that are conducted on the NTS to protect the public and the environment from radiation hazards and from nonradiological impacts. The NTSER is a comprehensive report of environmental activities performed at the NTS and offsite facilities over the previous calendar year. It is prepared annually to meet the requirements and guidelines of the U.S. Department of Energy (DOE) and the information needs of NNSA/NSO stakeholders. This summary provides an abbreviated and more readable version of the NTSER. It does not contain detailed descriptions or presentations of monitoring designs, data collection methods, data tables, the NTS environment, or all environmental program activities performed throughout the year. The reader may obtain a hard copy of the full NTSER as directed on the inside front cover of this summary report.
Date: September 13, 2010
Creator: Cathy Wills, ed.
Object Type: Report
System: The UNT Digital Library
Anomalous Electron Transport Due to Multiple High Frequency Beam Ion Driven Alfven Eigenmode (open access)

Anomalous Electron Transport Due to Multiple High Frequency Beam Ion Driven Alfven Eigenmode

We report on the simulations of recently observed correlations of the core electron transport with the sub-thermal ion cyclotron frequency instabilities in low aspect ratio plasmas of the National Spherical Torus Experiment (NSTX). In order to model the electron transport of the guiding center code ORBIT is employed. A spectrum of test functions of multiple core localized Global shear Alfven Eigenmode (GAE) instabilities based on a previously developed theory and experimental observations is used to examine the electron transport properties. The simulations exhibit thermal electron transport induced by electron drift orbit stochasticity in the presence of multiple core localized GAE.
Date: July 13, 2010
Creator: Gorelenkov, N. N.; Stutman, D.; Tritz, K.; Boozer, A.; Delgardo-Aparicio, L.; Fredrickson, E. et al.
Object Type: Report
System: The UNT Digital Library
FUEL CYCLE POTENTIAL WASTE FOR DISPOSITION (open access)

FUEL CYCLE POTENTIAL WASTE FOR DISPOSITION

The United States (U.S.) currently utilizes a once-through fuel cycle where used nuclear fuel (UNF) is stored on-site in either wet pools or in dry storage systems with ultimate disposal in a deep mined geologic repository envisioned. Within the Department of Energy's (DOE) Office of Nuclear Energy (DOE-NE), the Fuel Cycle Research and Development Program (FCR&D) develops options to the current commercial fuel cycle management strategy to enable the safe, secure, economic, and sustainable expansion of nuclear energy while minimizing proliferation risks by conducting research and development of advanced fuel cycles, including modified open and closed cycles. The safe management and disposition of used nuclear fuel and/or nuclear waste is a fundamental aspect of any nuclear fuel cycle. Yet, the routine disposal of used nuclear fuel and radioactive waste remains problematic. Advanced fuel cycles will generate different quantities and forms of waste than the current LWR fleet. This study analyzes the quantities and characteristics of potential waste forms including differing waste matrices, as a function of a variety of potential fuel cycle alternatives including: (1) Commercial UNF generated by uranium fuel light water reactors (LWR). Four once through fuel cycles analyzed in this study differ by varying the assumed expansion/contraction …
Date: October 13, 2010
Creator: Jones, R. & Carter, J.
Object Type: Article
System: The UNT Digital Library

Field Test of a DHW Distribution System: Temperature and Flow Analyses

This presentation discusses a field test of a DHW distribution system in an occupied townhome. It includes measured fixture flows and temperatures, a tested recirculation system, evaluated disaggregation of flow by measured temperatures, Aquacraft Trace Wizard analysis, and comparison.
Date: May 13, 2010
Creator: Barley, C. D.; Hendron, B. & Magnusson, L.
Object Type: Presentation
System: The UNT Digital Library
POTENTIAL IMPACT OF TANK F FLUSH SOLUTION  ON H-CANYON EVAPORATOR OPERATION (open access)

POTENTIAL IMPACT OF TANK F FLUSH SOLUTION ON H-CANYON EVAPORATOR OPERATION

Previous chemical analysis of a sample from the liquid heel found in Tank F of the High Activity Drain (HAD) system in F/H laboratory revealed the presence of n-paraffin, tributyl phosphate (TBP), Modifier from the Modular Caustic-Side Solvent Extraction Unit (MCU) process and a vinyl ester resin that is very similar to the protective lining on Tank F. Subsequent analyses detected the presence of a small amount of diisopropylnaphthalene (DIN) (major component of Ultima Gold{trademark} AB liquid scintillation cocktail). Indications are that both vinyl ester resin and DIN are present in small amounts in the flush solution. The flush solution currently in the LR-56S trailer likely has an emulsion which is believed to contain a mixture of the reported organic species dominated by TBP. An acid treatment similar to that proposed to clear the HAD tank heel in F/H laboratory was found to allow separation of an organic phase from the cloudy sample tested by SRNL. Mixing of that clear sample did re-introduce some cloudiness that did not immediately clear but that cloudiness is attributed to the DIN in the matrix. An organic phase does quickly separate from the cloudy matrix allowing separation by a box decanter in H-Canyon prior …
Date: September 13, 2010
Creator: Kyser, E.; Fondeur, F. & Fink, S.
Object Type: Report
System: The UNT Digital Library
Tank 40 Final SB6 Chemical Characterization Results (open access)

Tank 40 Final SB6 Chemical Characterization Results

A sample of Sludge Batch 6 (SB6) was taken from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS), and a portion of the sample was designated for SB6 processing studies. The SB6 WAPS sample was also analyzed for chemical composition including noble metals and fissile composition, and these results are reported here. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is currently being fed to DWPF as SB6. At the Savannah River National Laboratory (SRNL) the 3-L Tank 40 SB6 sample was transferred from the shipping container into a 4-L high density polyethylene vessel and solids were allowed to settle overnight. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 485 g sub-sample was removed. This sub-sample was then utilized for all subsequent analytical samples.
Date: August 13, 2010
Creator: Bannochie, C.
Object Type: Report
System: The UNT Digital Library
Ecological Monitoring and Compliance Program 2009 Report (open access)

Ecological Monitoring and Compliance Program 2009 Report

The Ecological Monitoring and Compliance Program (EMAC), funded through the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, monitors the ecosystem of the Nevada Test Site and ensures compliance with laws and regulations pertaining to NTS biota. This report summarizes the program’s activities conducted by National Security Technologies, LLC, during calendar year 2009. Program activities included (a) biological surveys at proposed construction sites, (b) desert tortoise compliance, (c) ecosystem mapping and data management, (d) sensitive plant species monitoring, (e) sensitive and protected/regulated animal monitoring, (f) habitat monitoring, (g) habitat restoration monitoring, and (h) monitoring of the Nonproliferation Test and Evaluation Complex. During 2009, all applicable laws, regulations, and permit requirements were met, enabling EMAC to achieve its intended goals and objectives.
Date: July 13, 2010
Creator: Hansen, J. Dennis; Anderson, David C.; Hall, Derek B.; Greger, Paul D. & Ostler, W. Kent
Object Type: Report
System: The UNT Digital Library
Metal Interconnect Materials for Solid Oxide Fuel Cells. Final Crada Report. (open access)

Metal Interconnect Materials for Solid Oxide Fuel Cells. Final Crada Report.

None
Date: July 13, 2010
Creator: Ehst, D. & Division, Nuclear Engineering
Object Type: Report
System: The UNT Digital Library
Borated Materials and Components for Nuclear Shielding and Waste Contamination Applications. Final Crada Report. (open access)

Borated Materials and Components for Nuclear Shielding and Waste Contamination Applications. Final Crada Report.

None
Date: July 13, 2010
Creator: Ehst, D. & Division, Nuclear Engineering
Object Type: Report
System: The UNT Digital Library
Low Emission Advanced Power Cycle. Final CRADA Report. (open access)

Low Emission Advanced Power Cycle. Final CRADA Report.

Today's gas turbines are based on the Brayton Cycle in which heat is added to the working fluid at constant pressure. An alternate approach, the Humphrey cycle, provides a higher theoretical thermal efficiency by adding heat at constant, or near constant volume. A few practical examples of such engines appeared in the mid 1900's, but they were largely superseded by the Brayton engine. Although the conventional gas turbine has been developed to a high level of efficiency and reliability, significant improvements in performance are becoming increasingly costly to obtain. Efficiencies of compressors, turbines and combustors are approaching theoretical limits. Cooling and materials technologies continue to improve but higher cycle temperatures may be limited by NOx emissions. While heat exchangers, intercoolers and other features improve cycle efficiency they add significantly to the cost, weight and volume of the basic engine and for flight applications may always be impractical. For these reasons there has been renewed interest in recent years in the constant volume Humphrey cycle focusing mainly on pulsing systems in which heat is added by a rapid series of detonations. Variations on this basic scheme are being evaluated for aircraft propulsions systems. General Electric has established a joint program with …
Date: July 13, 2010
Creator: Tentner, A. & Division, Nuclear Engineering
Object Type: Report
System: The UNT Digital Library
Characterization of microbial communities in subsurface nuclear blast cavities of the Nevada Test Site (open access)

Characterization of microbial communities in subsurface nuclear blast cavities of the Nevada Test Site

This US Department of Energy (DOE) Environmental Remediation Sciences Project (ERSP) was designed to test fundamental hypotheses concerning the existence and nature of indigenous microbial populations of Nevada Test Site subsurface nuclear test/detonation cavities. Now called Subsurface Biogeochemical Research (SBR), this program’s Exploratory Research (ER) element, which funded this research, is designed to support high risk, high potential reward projects. Here, five cavities (GASCON, CHANCELLOR, NASH, ALEMAN, and ALMENDRO) and one tunnel (U12N) were sampled using bailers or pumps. Molecular and cultivation-based techniques revealed bacterial signatures at five sites (CHANCELLOR may be lifeless). SSU rRNA gene libraries contained diverse and divergent microbial sequences affiliated with known metal- and sulfur-cycling microorganisms, organic compound degraders, microorganisms from deep mines, and bacteria involved in selenate reduction and arsenite oxidation. Close relatives of Desulforudis audaxviator, a microorganism thought to subsist in the terrestrial deep subsurface on H2 and SO42- produced by radiochemical reactions, was detected in the tunnel waters. NTS-specific media formulations were used to culture and quantify nitrate-, sulfate-, iron-reducing, fermentative, and methanogenic microorganisms. Given that redox manipulations mediated by microorganisms can impact the mobility of DOE contaminants, our results should have implications for management strategies at this and other DOE sites.
Date: July 13, 2010
Creator: Moser, Duane P.; Czerwinski, Ken; Russell, Charles E. & Zavarin, Mavrik
Object Type: Report
System: The UNT Digital Library
Nevada Test Site Environmental Report 2009, Attachment A: Site Description (open access)

Nevada Test Site Environmental Report 2009, Attachment A: Site Description

This attachment expands on the general description of the Nevada Test Site (NTS) presented in the Introduction to the Nevada Test Site Environmental Report 2009. Included are subsections that summarize the site’s geological, hydrological, climatological, and ecological setting. The cultural resources of the NTS are also presented. The subsections are meant to aid the reader in understanding the complex physical and biological environment of the NTS. An adequate knowledge of the site’s environment is necessary to assess the environmental impacts of new projects, design and implement environmental monitoring activities for current site operations, and assess the impacts of site operations on the public residing in the vicinity of the NTS. The NTS environment contributes to several key features of the site that afford protection to the inhabitants of adjacent areas from potential exposure to radioactivity or other contaminants resulting from NTS operations. These key features include the general remote location of the NTS, restricted access, extended wind transport times, the great depths to slow-moving groundwater, little or no surface water, and low population density. This attachment complements the annual summary of monitoring program activities and dose assessments presented in the main body of this report.
Date: September 13, 2010
Creator: Cathy Wills, ed.
Object Type: Report
System: The UNT Digital Library
Results of groundwater monitoring and vegetation sampling at Everest, Kansas, in 2009 . (open access)

Results of groundwater monitoring and vegetation sampling at Everest, Kansas, in 2009 .

In April 2008, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) conducted groundwater sampling for the analysis of volatile organic compounds (VOCs) in the existing network of monitoring points at Everest, Kansas (Argonne 2008). The objective of the 2008 investigation was to monitor the distribution of carbon tetrachloride contamination in groundwater previously identified in CCC/USDA site characterization and groundwater sampling studies at Everest in 2000-2006 (Argonne 2001, 2003, 2006a,b). The work at Everest is being undertaken on behalf of the CCC/USDA by Argonne National Laboratory, under the oversight of the Kansas Department of Health and Environment (KDHE). The findings of the 2008 investigation were as follows: (1) Measurements of groundwater levels obtained manually and through the use of automatic recorders demonstrated a consistent pattern of groundwater flow - and inferred contaminant migration - to the north-northwest from the former CCC/USDA facility toward the Nigh property, and then west-southwest from the Nigh property toward the intermittent creek that lies west of the former CCC/USDA facility and the Nigh property. (2) The range of concentrations and the areal distribution of carbon tetrachloride identified in the groundwater at Everest in April 2008 were generally consistent with previous results. The results …
Date: May 13, 2010
Creator: LaFreniere, L. M. & Division, Environmental Science
Object Type: Report
System: The UNT Digital Library
Simulation of e-cloud driven instability and its attenuation using a simulated feedback system in the CERN SPS (open access)

Simulation of e-cloud driven instability and its attenuation using a simulated feedback system in the CERN SPS

Electron clouds have been shown to trigger fast growing instabilities on proton beams circulating in the SPS, and a feedback system to control the single-bunch instabilities is under active development. We present the latest improvements to the WARP-POSINST simulation framework and feedback model, and its application to the self-consistent simulations of two consecutive bunches interacting with an electron cloud in the SPS. Simulations using an idealized feedback system exhibit adequate mitigation of the instability providing that the cutoff of the feedback bandwidth is at or above 450 MHz. Artifacts from numerical noise of the injected distribution of electrons in the modeling of portions of bunch trains are discussed, and benchmarking of WARP against POSINST and HEADTAIL are presented.
Date: December 13, 2010
Creator: Vay, J. L. & Furman, M. A.
Object Type: Article
System: The UNT Digital Library
First Measurements and Results With a Stretched Wire Test Setup (open access)

First Measurements and Results With a Stretched Wire Test Setup

The LINAC Coherent Light Source [LCLS] is a free electron laser, designed to produce high brilliant X-ray beams using Self Amplified Spontaneous Emission [SASE]. Due to the physics of SASE, the electron beam has to be held very precisely on the same trajectory as the X-ray light beam generated by the undulator magnets. To optimize the SASE output, trajectory deviations between both beams have to be minimized to a few micrometers along the entire undulator section and held stable over the time period between beam-based-alignment processes. Consequently, extremely high position stability of all magnets in the undulator section is required to operate the LCLS successfully. The knowledge of any magnet movement exceeding few micrometers during periods of several weeks is essential for efficient X-ray generation. A well known principle of monitoring transverse component positions along beam lines is the application of stretched wires, associated with suitable wire position sensors and electronics. The particular challenge at LCLS is the required wire system performance in conjunction with the length of the undulator section and the large number of monitors. Verification of system stability and resolution under real conditions is the primary goal of this test setup. A stretched wire test setup has …
Date: December 13, 2010
Creator: Peters, Franz
Object Type: Report
System: The UNT Digital Library
High Efficiency Engine Technologies Program (open access)

High Efficiency Engine Technologies Program

Caterpillar's Product Development and Global Technology Division carried out a research program on waste heat recovery with support from DOE (Department of Energy) and the DOE National Energy Technology Laboratory. The objective of the program was to develop a new air management and exhaust energy recovery system that would demonstrate a minimum 10% improvement in thermal efficiency over a base heavy-duty on-highway diesel truck engine. The base engine for this program was a 2007 C15 15.2L series-turbocharged on-highway truck engine with a LPL (low-pressure loop) exhaust recirculation system. The focus of the program was on the development of high efficiency turbomachinery and a high efficiency turbocompound waste heat recovery system. The focus of each area of development was as follows: (1) For turbine stages, the focus was on investigation and development of technologies that would improve on-engine exhaust energy utilization compared to the conventional radial turbines in widespread use today. (2) For compressor stages, the focus was on investigating compressor wheel design parameters beyond the range typically utilized in production, to determine the potential efficiency benefits thereof. (3) For turbocompound, the focus was on the development of a robust bearing system that would provide higher bearing efficiencies compared to systems …
Date: July 13, 2010
Creator: Kruiswyk, Rich
Object Type: Report
System: The UNT Digital Library
Quark mass variation constraints from Big Bang nucleosynthesis (open access)

Quark mass variation constraints from Big Bang nucleosynthesis

We study the impact on the primordial abundances of light elements created of a variation of the quark masses at the time of Big Bang nucleosynthesis (BBN). In order to navigate through the particle and nuclear physics required to connect quark masses to binding energies and reaction rates in a model-independent way we use lattice QCD data and an hierarchy of effective field theories. We find that the measured {sup 4}He abundances put a bound of {delta}-1% {approx}< m{sub q}/m{sub 1} {approx}< 0.7%. The effect of quark mass variations on the deuterium abundances can be largely compensated by changes of the baryon-to-photon ratio {eta}. Including the bounds on the variation of {eta} coming from WMAP results and some additional assumptions narrows the range of allowed values of {delta}m{sub q}/m{sub q} somewhat.
Date: December 13, 2010
Creator: Bedaque, P.; Luu, T. & Platter, L.
Object Type: Article
System: The UNT Digital Library
Wakefield Calculations for Radiation Stopper 1 (RST1) (open access)

Wakefield Calculations for Radiation Stopper 1 (RST1)

The main result of this note is that no wakefield mitigation is required for the Radiation Stopper (RST1) in the LCLS injector. The RST1 geometry is not symmetric in the vertical direction, and we derive a slight modification to the diffraction model wake for a cylindrically symmetric (2D) cavity that can be used for this problem. Performing a full 3D MAFIA calculation for the nominal 1 mm (rms) long bunch, we show that the modified diffraction model well describes the wakefields generated in RST1. The results imply an on-axis emittance growth of 0.0075%, well below the 0.5% tolerance threshold. To reach the 0.5% threshold the beam would need to be mis-steered by a large amount - 7 mm - from the axis. One reason that the effect is small is that the beta functions at the RST1 are small.
Date: December 13, 2010
Creator: Limborg-Deprey, C.
Object Type: Report
System: The UNT Digital Library
Tests of Coordinate Transfer from Magnetic to Mechanical Reference for LCLS Undulator Fiducialization (open access)

Tests of Coordinate Transfer from Magnetic to Mechanical Reference for LCLS Undulator Fiducialization

Fiducialization of the LCLS undulators will be based on magnetic measurements by Hall probe. Pointed magnets, proposed by I.Vasserman for quadrupole lens fiducialization will be used as an intermediate reference. A prototype of the pointed magnet fixture has been made and tested. In this note we will describe a procedure for measuring the position of the center of the Hall probe sensitive area with respect to the undulator fiducial marks. The pointed magnet calibration procedure, a two-point algorithm for locating the magnetic center of the fixture, and test results are presented.
Date: December 13, 2010
Creator: Levashov, Yu.
Object Type: Report
System: The UNT Digital Library
Temperature Measurements in the Magnetic Measurement Facility (open access)

Temperature Measurements in the Magnetic Measurement Facility

Several key LCLS undulator parameter values depend strongly on temperature primarily because of the permanent magnet material the undulators are constructed with. The undulators will be tuned to have specific parameter values in the Magnetic Measurement Facility (MMF). Consequently, it is necessary for the temperature of the MMF to remain fairly constant. Requirements on undulator temperature have been established. When in use, the undulator temperature will be in the range 20.0 {+-} 0.2 C. In the MMF, the undulator tuning will be done at 20.0 {+-} 0.1 C. For special studies, the MMF temperature set point can be changed to a value between 18 C and 23 C with stability of {+-}0.1 C. In order to ensure that the MMF temperature requirements are met, the MMF must have a system to measure temperatures. The accuracy of the MMF temperature measurement system must be better than the {+-}0.1 C undulator tuning temperature tolerance, and is taken to be {+-}0.01 C. The temperature measurement system for the MMF is under construction. It is similar to a prototype system we built two years ago in the Sector 10 alignment lab at SLAC. At that time, our goal was to measure the lab temperature …
Date: December 13, 2010
Creator: Wolf, Zachary
Object Type: Report
System: The UNT Digital Library
RF Design of the LCLS Gun (open access)

RF Design of the LCLS Gun

Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun [1], referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee [2]. Files and …
Date: December 13, 2010
Creator: Limborg-Deprey, C
Object Type: Report
System: The UNT Digital Library