First Polarized Proton Collisions at RHIC. (open access)

First Polarized Proton Collisions at RHIC.

We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV.
Date: November 6, 2002
Creator: Roser, T.; Ahrens, L.; Alessi, J.; Bai, M.; Beebe-Wang, J.; Brennan, J. M. et al.
Object Type: Article
System: The UNT Digital Library
Residual stress mapping by micro X-ray diffraction: Application to the study of thin film buckling (open access)

Residual stress mapping by micro X-ray diffraction: Application to the study of thin film buckling

Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of spontaneous detachment of the film from its substrate and in the case of compressive stresses, thin film buckling. Although these effects are undesirable for future applications, one may take benefit of it for thin film mechanical properties investigation. Since the 80's, a lot of theoretical works have been done to develop mechanical models with the aim to get a better understanding of driven mechanisms giving rise to this phenomenon and thus to propose solutions to avoid such problems. Nevertheless, only a few experimental works have been done on this subject to support these theoretical results and nothing concerning local stress/strain measurement mainly because of the small dimension of the buckling (few tenth mm). This paper deals with the application of micro beam x-ray diffraction available on synchrotron radiation sources for stress/ strain mapping analysis of gold thin film buckling.
Date: November 6, 2002
Creator: Goudeau, P.; Villain, P.; Tamura, N.; Celestre, R. S. & Padmore, H. A.
Object Type: Article
System: The UNT Digital Library
Spin Matching From Ags to RHIC. (open access)

Spin Matching From Ags to RHIC.

With a partial Siberian snake in the AGS and transport lines with interspersed horizontal and vertical bends, the incoming spin direction at the injection points of both the collider rings is not likely to match the ideal vertical stable spin direction of RHIC which has two full helical Siberian snakes per ring. In this paper we examine the matching of a polarized beam transferred from the AGS into RHIC. The present 5% partial solenoidal snake as well as a proposed 20% superconducting helical are considered for the AGS. Solutions with retuned snakes in RHIC to better match the incoming beam have been found.
Date: November 6, 2002
Creator: MacKay, W. W. & Tsoupas, N.
Object Type: Article
System: The UNT Digital Library
Assessment of MTI Water Temperature Thermal Discharge Retrievals with Ground Truth (open access)

Assessment of MTI Water Temperature Thermal Discharge Retrievals with Ground Truth

Surface water temperatures calculated from Multispectral Thermal Imager (MTI) brightness temperatures and the robust retrieval algorithm, developed by the Los Alamos National Laboratory (LANL), are compared with ground truth measurements at a mid-latitude cold-water site along the Atlantic coast near Plymouth, MA. In contrast to the relative uniformity of the sea-surface temperature in the open ocean the water temperature near Pilgrim exhibits strong spatial gradients and temporal variability. This made it critical that all images be accurately registered in order to extract temperature values at the six buoy locations. Sixteen images during a one-year period from August 2000 to July 2001 were selected for the study. The RMS error of Pilgrim water temperature is about 3.5 C for the 4 buoys located in open water. The RMS error of the combined temperatures from 3 of the open-water buoys is 2.8 C. The RMS error includes errors in the ground truth. The magnitude of this error is estimated to range between 0.8 and 2.3 C. The two main components of this error are warm-layer effect and spatial variability. The actual error in the MTI retrievals for Pilgrim daytime conditions is estimated to be between 2.7 and 3.4 C for individual buoys …
Date: December 6, 2002
Creator: Kurzeja, R.J.
Object Type: Report
System: The UNT Digital Library
Macro stress mapping on thin film buckling (open access)

Macro stress mapping on thin film buckling

Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of thin film buckling in the case of compressive stresses. Since the 80's, a lot of theoretical work has been done to develop mechanical models but only a few experimental work has been done on this subject to support these theoretical approaches and nothing concerning local stress measurement mainly because of the small dimension of the buckling (few 10th mm). This paper deals with the application of micro beam X-ray diffraction available on synchrotron radiation sources for stress mapping analysis of gold thin film buckling.
Date: November 6, 2002
Creator: Goudeau, P.; Villain, P.; Renault, P. O.; Tamura, N.; Celestre, R. S. & Padmore, H.A.
Object Type: Article
System: The UNT Digital Library
Tank Remote Repair System Conceptual Design (open access)

Tank Remote Repair System Conceptual Design

This document describes two conceptual designs for a Tank Remote Repair System to perform leak site repairs of double shell waste tank walls (Types I, II, III, and IIIA) from the annulus space. The first concept uses a magnetic wall crawler and an epoxy patch system and the second concept uses a magnetic wall crawler and a magnetic patch system. The recommended concept uses the magnetic patch system, since it is simpler to deliver, easier to apply, and has a higher probability of stopping an active leak.
Date: December 6, 2002
Creator: Kriikku, E.
Object Type: Report
System: The UNT Digital Library
Negative heat capacities and first order phase transitions in nuclei (open access)

Negative heat capacities and first order phase transitions in nuclei

None
Date: August 6, 2002
Creator: Moretto, L. G.; Elliott, J. B.; Phair, L. & Wozniak, G. J.
Object Type: Article
System: The UNT Digital Library
Corrective Action Investigation Plan for Corrective Action Unit 527: Horn Silver Mine, Nevada Test Site, Nevada: Revision 1 (Including Records of Technical Change No.1, 2, 3, and 4) (open access)

Corrective Action Investigation Plan for Corrective Action Unit 527: Horn Silver Mine, Nevada Test Site, Nevada: Revision 1 (Including Records of Technical Change No.1, 2, 3, and 4)

This Corrective Action Investigation Plan contains the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 527, Horn Silver Mine, Nevada Test Site, Nevada, under the Federal Facility Agreement and Consent Order. Corrective Action Unit 527 consists of one Corrective Action Site (CAS): 26-20-01, Contaminated Waste Dump No.1. The site is located in an abandoned mine site in Area 26 (which is the most arid part of the NTS) approximately 65 miles northwest of Las Vegas. Historical documents may refer to this site as CAU 168, CWD-1, the Wingfield mine (or shaft), and the Wahmonie mine (or shaft). Historical documentation indicates that between 1959 and the 1970s, nonliquid classified material and unclassified waste was placed in the Horn Silver Mine's shaft. Some of the waste is known to be radioactive. Documentation indicates that the waste is present from 150 feet to the bottom of the mine (500 ft below ground surface). This CAU is being investigated because hazardous constituents migrating from materials and/or wastes disposed of in the Horn Silver Mine may pose a threat to human …
Date: December 6, 2002
Creator: U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office
Object Type: Report
System: The UNT Digital Library
Improved Austenitic Steels for Power Plant Applications (open access)

Improved Austenitic Steels for Power Plant Applications

Using alloy design principles, an austenitic alloy, with base composition of Fe-16Cr-16Ni-2Mn-1Mo (in weight percent, wt%), was formulated to which up to 5 wt% Si and/or Al were added specifically to improve the oxidation resistance. Cyclic oxidation tests were carried out in air at 700 and 800 C for 1000 hours. For comparison, Fe-18Cr-8Ni type-304 stainless steel alloys was also tested. The results showed that at 700 C, all the alloys were twice as oxidation resistant as the type-304 alloy (i.e., the experimental alloys showed weight gains about half that of type-304). Surprisingly, at 800 C, alloys that contained both Al and Si additions were less oxidation resistant than the type-304 alloy. However, alloys containing only Si additions were significantly more oxidation resistant than the type 304 alloys (i.e., showed weight gains 4 times less than the type-304 alloy). Further, alloys with only Si additions pre-oxidized at 800 C, showed zero weight gain in subsequent testing for 1000 hours at 700 C. This implies the potential for producing in-situ protective coating for these alloys. Preliminary exposure tests (1%H2S at 700 C for 360 hrs) indicated that the Si-modified alloys are more sulfidation resistant than type-304 alloy. The mechanical properties of …
Date: August 6, 2002
Creator: Alman, David E.; Dunning, John S.; Schrems, Karol K.; Rawers, James C.; Wilson, Rick D.; Hawk, Jeffrey A. et al.
Object Type: Article
System: The UNT Digital Library
Thoughts and ''Facts'' From the Ags Polarized Proton Runs During the 1980s. (open access)

Thoughts and ''Facts'' From the Ags Polarized Proton Runs During the 1980s.

This workshop's focus is on considering ways for improving the proton beam polarization that the AGS delivers to the RHIC. This talk attempts to review the first decade of AGS polarization--the 1980's; to briefly describe some aspects of the machine situation, the depolarization avoidance strategies employed and the success achieved in AGS from the perspective of one of those involved.
Date: November 6, 2002
Creator: Ahrens, L.
Object Type: Article
System: The UNT Digital Library
Technical report to DOE for Award 81.049, Support for two joint VEMAP workshops (open access)

Technical report to DOE for Award 81.049, Support for two joint VEMAP workshops

This award was used to hold one large workshop in Polson, Montana, in July 1997 to better understand the response of terrestrial ecosystems to increased carbon dioxide concentrations at large spatial scales and over long time periods, and to develop validation tests for models that attempt to simulate these processes. The workshop participants included members of the Vegetation/Ecosystem Modeling and Analysis (VEMAP) and the CO{sub 2} Models/Experiments Activity for improved Links (CMEAL) groups. Results and recommendations of the workshop are summarized. A reprint of the paper ''Carbon Sequestration Studied in Western U.S. Mountains'' is attached.
Date: November 6, 2002
Creator: Melillo, Jerry M.
Object Type: Report
System: The UNT Digital Library
Validation and Comparison of KENO V.a and KENO-VI (open access)

Validation and Comparison of KENO V.a and KENO-VI

This report documents the validation and comparison of KENO V.a and KENO-VI using the SCALE 27-group ENDF/B-IV and 238-group ENDF/B-V cross-section libraries against critical experiments. Experiments considered were primarily high- or low-enriched uranium systems. The results indicate that KENO V.a and KENO-VI Monte Carlo Criticality Programs accurately calculate a broad range of critical experiments. A number of the calculations showed a positive or negative bias in excess of 1 1/2% in k-effective (k{sub eff}). Classes of criticals that show a bias include 3% enriched green blocks, highly-enriched uranyl fluoride slab arrays, and highly-enriched uranyl nitrate arrays. If these biases are properly taken into account, KENO V.a and KENO-VI can be used with confidence for the design and criticality safety analysis of uranium-containing systems. KENO V.a and KENO-VI calculate the same k{sub eff} for a system within statistics and thus may be used interchangeably as long as the geometry of the problem can be modeled.
Date: May 6, 2002
Creator: Fox, P.B.
Object Type: Report
System: The UNT Digital Library
Direct Determination of the Stacking Order in GD2O3 EPI Layers on GAAS. (open access)

Direct Determination of the Stacking Order in GD2O3 EPI Layers on GAAS.

We have used Coherent Bragg Rod Analysis (COBRA) to investigate the atomic structure of a 5.6 nm thick Gd{sub 2}O{sub 3} film epitaxially grown on a (100) GaAs substrate. COBRA is a method to directly obtain the structure of systems periodic in two-dimensions by determining the complex scattering factors along the substrate Bragg rods. The system electron density and atomic structure are obtained by Fourier transforming the complex scattering factors into real space. The results show that the stacking order of the first seven Gd{sub 2}O{sub 3} film layers resembles the stacking order of Ga and As layers in GaAs then changes to the stacking order of cubic bulk Gd{sub 2}O{sub 3}. This behavior is distinctly different from the measured stacking order in a 2.7 nm thick Gd{sub 2}O{sub 3} in which the GaAs stacking order persists throughout the entire film.
Date: December 6, 2002
Creator: Yacoby, Y.; Sowman, M.; Pindak, R.; Cross, J.; Walko, D.; Stern, E. et al.
Object Type: Article
System: The UNT Digital Library