Beam Energy Scaling of Ion-Induced Electron Yield from K+ Impact on Stainless Steel (open access)

Beam Energy Scaling of Ion-Induced Electron Yield from K+ Impact on Stainless Steel

Electron clouds limit the performance of many major accelerators and storage rings. Significant quantities of electrons result when halo ions are lost to beam tubes, generating gas which can be ionized and ion-induced electrons that can multiply and accumulate, causing degradation or loss of the ion beam. In order to understand the physical mechanisms of ion-induced electron production, experiments studied the impact of 50 to 400 keV K{sup +} ions on stainless steel surfaces near grazing incidence, using the 500 kV Ion Source Test Stand (STS-500) at LLNL. The experimental electron yield scales with the electronic component (dE{sub e}/dx) of the stopping power and its angular dependence does not follow l/cos({theta}). A theoretical model is developed, using TRIM code to evaluate dE{sub e}/dx at several depths in the target, to estimate the electron yield, which is compared with the experimental results. The experiment extends the range of energy from previous works and the model reproduces the angular dependence and magnitude of the electron yield.
Date: March 6, 2006
Creator: Covo, M K; Molvik, A; Friedman, A; Westenskow, G; Barnard, J J; Cohen, R et al.
Object Type: Article
System: The UNT Digital Library
ISOPAR L Release Rates from Saltstone Using Simulated Salt Solutions (open access)

ISOPAR L Release Rates from Saltstone Using Simulated Salt Solutions

The Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) and the Salt Waste Processing Facility (SWPF) will produce a Deactivated Salt Solution (DSS) that will go to the Saltstone Production Facility (SPF). Recent information indicates that solvent entrainment in the DSS is larger than expected. The main concern is with Isopar{reg_sign} L, the diluent in the solvent mixture, and its flammability in the saltstone vault. If it is assumed that all the Isopar{reg_sign} L is released instantaneously into the vault from the curing grout before each subsequent pour; the Isopar{reg_sign} L in the vault headspace is well mixed; and each pour displaces an equivalent volume of headspace, the allowable concentration of Isopar{reg_sign} L in the DSS sent to SPF has been calculated at approximately 4 ppm. The amount allowed would be higher, if the release from grout were significantly less. The Savannah River National Laboratory was tasked with determining the release of Isopar{reg_sign} L from saltstone prepared with a simulated DSS with Isopar{reg_sign} L concentrations ranging from 50 mg/L to 200 mg/L in the salt fraction and with test temperatures ranging from ambient to 95 C. The results from the curing of the saltstone showed that the Isopar{reg_sign} L release data …
Date: February 6, 2006
Creator: Bronikowski, M
Object Type: Report
System: The UNT Digital Library
Research on Previous BRAC Lawsuits ('91, '93, '95) (open access)

Research on Previous BRAC Lawsuits ('91, '93, '95)

Research on Previous BRAC Lawsuits ('91, '93, '95).
Date: January 6, 2006
Creator: United States. Defense Base Closure and Realignment Commission.
Object Type: Text
System: The UNT Digital Library
Immigration Enforcement within the United States (open access)

Immigration Enforcement within the United States

This report provides an analysis of immigration enforcement within the United States. The report opens with a definition of immigration enforcement, a discussion of the statutory authority to conduct immigration enforcement, and an overview of immigration enforcement related legislation since 1986. It follows with an exposition on the dichotomy of interior and border enforcement. The report then details different aspects of immigration enforcement in the United States including detention and removal, alien smuggling and trafficking, document and benefit fraud, worksite enforcement, inspections at ports of entry, and patrolling the border between ports of entry. The report continues with a discussion of the role of state and local law enforcement in the enforcement of immigration laws. The report then presents a comparative analysis of the resources devoted to divergent immigration enforcement activities. It concludes with a discussion of crosscutting immigration enforcement issues related to the structure of the Department of Homeland Security.
Date: April 6, 2006
Creator: Siskin, Alison; Bruno, Andorra; Nuñez-Neto, Blas; Seghetti, Lisa M. & Wasem, Ruth Ellen
Object Type: Report
System: The UNT Digital Library
General Counsel - Air National Guard - Legal Opinions (2005) (open access)

General Counsel - Air National Guard - Legal Opinions (2005)

General Counsel - Air National Guard - Legal Opinions (2005).
Date: January 6, 2006
Creator: United States. Defense Base Closure and Realignment Commission.
Object Type: Text
System: The UNT Digital Library
Texas Register, Volume 31, Number 1, Pages 1-208, January 6, 2006 (open access)

Texas Register, Volume 31, Number 1, Pages 1-208, January 6, 2006

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: January 6, 2006
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History