Design and Start-to-End Simulation of an X-Band RF Driven Hard X-Ray FEL with LCLS Injector (open access)

Design and Start-to-End Simulation of an X-Band RF Driven Hard X-Ray FEL with LCLS Injector

In this note, it is briefly discussed the accelerator design and start-to-end 3D macro particles simulation (using ELEGANT and GENESIS) of an X-band RF driven hard X-ray FEL with LCLS injector. A preliminary design and LiTrack 1D simulation studies were presented before in an older publication [1]. In numerical simulations this X-band RF driven hard X-ray FEL achieves/exceeds LCLS-like performance in a much shorter overall length of 350 m, compared with 1200 m in the LCLS case. One key feature of this design is that it may achieve a higher final beam current of 5 kA plus a uniform energy profile, mainly due to the employment of stronger longitudinal wake fields in the last X-band RF linac [2].
Date: August 20, 2012
Creator: Sun, Yipeng
Object Type: Report
System: The UNT Digital Library
Final Report (open access)

Final Report

The goal of this project was to quantify organic aerosol precursor concentrations in an urban environment and to measure suitable organic photoproduct species that can act as tracers of photochemical processing to identify the occurrence and rate of secondary organic aerosol formation. Field measurements were made as part of the ASR field program Carbonaceous Aerosols and Radiative Effects Study (CARES) in June 2010. What is new in our approach is the measurement for the total concentration of long chain alkanes (>C10) and heavier alkyl substituted aromatics associated with diesel exhaust gas phase organic compound emissions. A method to measure these so called intermediate volatility organic compounds (IVOCs) was developed by modifying a proton transfer reaction mass spectrometer instrument to perform both volatile organic compound (VOC) and IVOC analysis by thermal desorption from a Tenax adsorbent trap (TD-PTR-MS). Lab and field results show that the TD-PTR-MS technique can measure long chain alkanes associated with diesel engine emissions and thus provide a novel means to measure these compounds to better understand the impact of vehicle emissions on secondary organic aerosol formation.
Date: August 20, 2012
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Solar Grade Silicon from Agricultural By-products (open access)

Solar Grade Silicon from Agricultural By-products

In this project, Mayaterials developed a low cost, low energy and low temperature method of purifying rice hull ash to high purity (5-6Ns) and converting it by carbothermal reduction to solar grade quality silicon (Sipv) using a self-designed and built electric arc furnace (EAF). Outside evaluation of our process by an independent engineering firm confirms that our technology greatly lowers estimated operating expenses (OPEX) to $5/kg and capital expenses (CAPEX) to $24/kg for Sipv production, which is well below best-in-class plants using a Siemens process approach (OPEX of 14/kg and CAPEX of $87/kg, respectively). The primary limiting factor in the widespread use of photovoltaic (PV) cells is the high cost of manufacturing, compared to more traditional sources to reach 6 g Sipv/watt (with averages closer to 8+g/watt). In 2008, the spot price of Sipv rose to $450/kg. While prices have since dropped to a more reasonable $25/kg; this low price level is not sustainable, meaning the longer-term price will likely return to $35/kg. The 6-8 g Si/watt implies that the Sipv used in a module will cost $0.21-0.28/watt for the best producers (45% of the cost of a traditional solar panel), a major improvement from the cost/wafer driven by the …
Date: August 20, 2012
Creator: Laine, Richard M.
Object Type: Report
System: The UNT Digital Library
Quarterly VAP Report - April to June (open access)

Quarterly VAP Report - April to June

The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, (3) future VAPs that have been recently approved, (4) other work that leads to a VAP, and (5) top requested VAPs from the Data Archive. New information is highlighted in blue text. New information about processed data by the developer is highlighted in red text. The upcoming milestones and dates are highlighted in green.
Date: August 20, 2012
Creator: Sivaraman, C
Object Type: Text
System: The UNT Digital Library
Nonproliferation Graduate Fellowship Program Annual Report: Class of 2011 (open access)

Nonproliferation Graduate Fellowship Program Annual Report: Class of 2011

Annual report for the Nonproliferation Graduate Fellowship Program (NGFP), which PNNL administers for the National Nuclear Security Administration (NNSA). Features the Class of 2011. The NGFP is a NNSA program with a mission to cultivate future technical and policy leaders in nonproliferation and international security. Through the NGFP, outstanding graduate students with career interests in nonproliferation are appointed to program offices within the Office of Defense Nuclear Nonproliferation (DNN). During their one-year assignment, Fellows participate in programs designed to detect, prevent, and reverse the proliferation of nuclear weapons.
Date: August 20, 2012
Creator: McMakin, Andrea H.
Object Type: Report
System: The UNT Digital Library
Benchmarking a New Closed-Form Thermal Analysis Technique Against a Traditional Lumped Parameter, Finite-Difference Method (open access)

Benchmarking a New Closed-Form Thermal Analysis Technique Against a Traditional Lumped Parameter, Finite-Difference Method

A benchmarking effort was conducted to determine the accuracy of a new analytic generic geology thermal repository model developed at LLNL relative to a more traditional, numerical, lumped parameter technique. The fast-running analytical thermal transport model assumes uniform thermal properties throughout a homogenous storage medium. Arrays of time-dependent heat sources are included geometrically as arrays of line segments and points. The solver uses a source-based linear superposition of closed form analytical functions from each contributing point or line to arrive at an estimate of the thermal evolution of a generic geologic repository. Temperature rise throughout the storage medium is computed as a linear superposition of temperature rises. It is modeled using the MathCAD mathematical engine and is parameterized to allow myriad gridded repository geometries and geologic characteristics [4]. It was anticipated that the accuracy and utility of the temperature field calculated with the LLNL analytical model would provide an accurate 'birds-eye' view in regions that are many tunnel radii away from actual storage units; i.e., at distances where tunnels and individual storage units could realistically be approximated as physical lines or points. However, geometrically explicit storage units, waste packages, tunnel walls and close-in rock are not included in the MathCAD …
Date: August 20, 2012
Creator: Huff, K. D. & Bauer, T. H. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library