CSER-98-002: Criticality analysis for the storage of special nuclear material sources and standards in the WRAP Facility (open access)

CSER-98-002: Criticality analysis for the storage of special nuclear material sources and standards in the WRAP Facility

The Waste Receiving and Processing (WRAP) Facility will store uranium and transuranic (TRU) sources and standards for certification that WRAP meets the requirements of the Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP). In addition, WRAP must meet internal requirements for testing and validation of measuring instruments for nondestructive assay (NDA). In order to be certified for WIPP, WRAP will participate in the NDA Performance Demonstration Program (PDP). This program is a blind test of the NDA capabilities for TRU waste. It is intended to ensure that the NDA capabilities of this facility satisfy the requirements of the quality assurance program plan for the WIPP. The PDP standards have been provided by the Los Alamos National Laboratory (LANL) for this program. These standards will be used in the WRAP facility. To internally check the accuracy and sensitivity of the NDA instruments, a further set of sources and standards will also be used by the facility. Each sealed source or standard will be referred to herein as a unit. Various combinations of these units will be placed in test drums and/or boxes which will be subject to their own limits until unloaded. There will be two sealed …
Date: June 22, 1998
Creator: Goldberg, H. J.
Object Type: Report
System: The UNT Digital Library
Iran: Arms and Technology Acquisitions (open access)

Iran: Arms and Technology Acquisitions

This report summarizes Iran's arms and technology acquisitions and the Clinton Administration and Congress' response to this. It discusses a bill passed by both the House and the Senate which imposes sanctions on foreign entities like Russia and China who contribute to Iran's efforts to develop ballistic missiles.
Date: June 22, 1998
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
China's Changing Conditions: Possible Implications for US Interests (open access)

China's Changing Conditions: Possible Implications for US Interests

This report discusses possible outcomes and implications for U.S. interests vary. For example, increasingly effective political administration and reform with continued successful economic modernization would be generally compatible with U.S. interests in greater economic opportunity, foreign policy cooperation, and political liberalization in China. Alternatively, Chinese administration, economic vitality, and internal cohesion could degenerate, limiting U.S. economic opportunities, challenging U.S. interests in stability in East Asia, but also diminishing potential threats from a strong China. Finally, China could develop formidable economic power while retaining authoritarian political control, with China emerging as a world power less interested in accommodating U.S. interests than in opposing them.
Date: June 22, 1998
Creator: Sutter, Robert G.
Object Type: Report
System: The UNT Digital Library
Support services for ceramic fiber-ceramic matrix composites. Annual technical progress report (open access)

Support services for ceramic fiber-ceramic matrix composites. Annual technical progress report

The University of North Dakota Energy and Environmental Research Center (EERC) is providing technical assistance and test materials to the US Department of Energy (DOE) Advanced Research and Technology Development (AR and TD) Materials Program investigating ceramic and advanced alloy corrosion in fossil energy systems. The main activity, which is reported here, is to perform thermochemical equilibrium calculations to develop recommendations for test conditions under which to perform corrosion measurements of structural and particle filter materials. The modeling is primarily being performed to determine possible mechanisms of corrosion, especially by species that vaporize in the gasifier then condense on downstream surfaces. For this year, the focus was on the stability of nickel in structural and filter alloys. This work was done in an effort to explain the existence of nickel-containing condensates found downstream of particulate filters in an EERC pilot-scale coal gasifier which operates under conditions similar to the Pinon Pine system, and to determine possible operating conditions that could reduce the wastage of nickel from structural and filter alloys.
Date: June 22, 1998
Creator: Hurley, John P. & Kuehnel, Vit
Object Type: Report
System: The UNT Digital Library
Energy-Momentum Tensor and Particle Creation in the De Sitter Universe (open access)

Energy-Momentum Tensor and Particle Creation in the De Sitter Universe

Particle creation in a conformally flat spacetime (e.g., FRW universe) requires a non-conformal field. The choice of state is crucial, as one may misunderstand the physics of particle creation by choosing a too restrictive vacuum for the quantum field. The authors exhibit a vacuum state in which the expectation values of the energy and pressure allow an intuitive physical interpretation. They apply this general result to the de Sitter universe.
Date: June 22, 1998
Creator: Molina-Paris, C.
Object Type: Article
System: The UNT Digital Library
Booster Gold Beam Injection Efficiency and Beam Loss (open access)

Booster Gold Beam Injection Efficiency and Beam Loss

The Relativistic Heavy Ion Collider (RHIC) at the BNL requires the AGS to provide Gold beam with the intensity of 10{sup 9} ions per bunch. Over the years, the Tandem Van de Graaff has provided steadily increasing intensity of gold ion beams to the AGS Booster. However, the gold beam injection efficiency at the Booster has been found to decrease with the rising intensity of injected beams. As the result, for Tandem beams of the highest intensity, the Booster late intensity is lower than with slightly lower intensity Tandem beam. In this article, the authors present two experiments associated with the Booster injection efficiency and beam intensity. One experiment looks at the Booster injection efficiency by adjusting the Tandem beam intensity, and another looks at the beam life time while scraping the beam in the Booster. The studies suggest that the gold beam injection efficiency at the AGS Booster is related to the beam loss in the ring, rather than the intensity of injected beam or circulating beam. A close look at the effect of the lost gold ion at the Booster injection leads to the prediction that the lost gold ion creates large number of positive ions, and even …
Date: June 22, 1998
Creator: Zhang, S. Y. & Ahrens, L. A.
Object Type: Article
System: The UNT Digital Library
RF Beam Control System for the Brookhaven Relativistic Heavy ION Collider, RHIC (open access)

RF Beam Control System for the Brookhaven Relativistic Heavy ION Collider, RHIC

The Relativistic Heavy Ion Collider, RHIC, is two counter-rotating rings with six interaction points. The RF Beam Control system for each ring will control two 28 MHz cavities for acceleration, and five 197 MHz cavities for preserving the 5 ns bunch length during 10 hour beam stores. Digital technology is used extensively in: Direct Digital Synthesis of rf signals and Digital Signal Processing for, the realization of state-variable feedback loops, real-time calculation of rf frequency, and bunch-by-bunch phase measurement of the 120 bunches. DSP technology enables programming the parameters of the feedback loops in order to obtain closed-loop dynamics that are independent of synchrotron frequency.
Date: June 22, 1998
Creator: Brennan, J. M.; Campbell, A.; DeLong, J.; Hayes, T.; Onillon, E.; Rose, J. et al.
Object Type: Article
System: The UNT Digital Library
Longitudinal Space Charge Effect for Sns (open access)

Longitudinal Space Charge Effect for Sns

One of performance requirements of the Spallation Neutron Source (SNS) is to keep the uncontrolled beam loss in the storage ring to less than 2 x 10{sup {minus}4} per pulse. For 2 MW SNS, the maximum beam intensity is N = 2 x 10{sup 14} protons per ring. Since the bunch lengthening has impact on both the extraction beam loss and the lowering of e-p instability threshold, the longitudinal space charge effect requires attentions. Such a space charge effect has been studied both analytically and using computer simulations. The longitudinal space charge effect, which is a defocusing force below transition, is a plausible source of the bunch leakage. In this article, the total RF potential, which takes into account the space charge effect together with the RF power, is used to provide analytical predictions for the bunch lengthening. The prediction is confirmed by the computer simulation. It is found that for 2 MW SNS storage ring, the longitudinal space charge induced bunch leakage into the interbunch gap is not significant. Therefore, corrections to the longitudinal space charge impedance, such as the proposed ferrite insertion in the PSR ring, are probably not necessary. Applying an RF voltage ramping from 20 KV …
Date: June 22, 1998
Creator: Zhang, S. Y. & Weng, W. T.
Object Type: Article
System: The UNT Digital Library
The Muon G-2 Storage Ring Magnet (open access)

The Muon G-2 Storage Ring Magnet

The muon g-2 experiment at Brookhaven National Laboratory has constructed a 7.112m radius superconducting magnet. The design and construction of the storage ring magnet are described.
Date: June 22, 1998
Creator: Lee, Y. Y.; Addessi, L.; Armoza, Z.; Benante, J.; Brown, H. N.; Bunce, G. et al.
Object Type: Article
System: The UNT Digital Library
CALDERON COKEMAKING PROCESS/DEMONSTRATION PROJECT (open access)

CALDERON COKEMAKING PROCESS/DEMONSTRATION PROJECT

This project deals with the demonstration of a coking process using proprietary technology of Calderon, with the following objectives geared to facilitating commercialization: (1) making coke of such quality as to be suitable for use in hard-driving, large blast furnaces; (2) providing proof that such process is continuous and environmentally closed to prevent emissions; (3) demonstrating that high-coking-pressure (non-traditional) coal blends which cannot be safely charged into conventional by-product coke ovens can be used in the Calderon process; and (4) demonstrating that coke can be produced economically, at a level competitive with coke imports. The activities of the past quarter were focused on three main activities: Continuation of design of the coking reactor; Raising funds from the private sector; and Detailed analysis of the tests conducted in Alliance, Ohio. The design of the reactor work centered on the provision for the capability to inspect and maintain the internals of the reactor. The activities relating to raising funds from the steel industry have been fruitful. Bethlehem Steel has agreed to contribute funds. The collected data from the tests at Alliance were analyzed and a detailed report was completed and presented to the International Iron & Steel Institute by invitation.
Date: June 22, 1998
Creator: CALDERON, ALBERT
Object Type: Report
System: The UNT Digital Library
Large volume manufacture of dymalloy (open access)

Large volume manufacture of dymalloy

The purpose of this research was to test the commercial viability and feasibility of Dymalloy, a composite material to measure thermal conductivity. Dymalloy was developed as part of a CRADA with Sun Microsystems. Sun Microsystems was a potential end user of Dymalloy as a substrate for MCMS. Sun had no desire to be involved in the manufacture of this material. The goal of this small business CRADA with Spectra Mat was to establish the high volume commercial manufacturing industry source for Dymalloy required by an end-user such as Sun Microsystems. The difference between the fabrication technique developed during the CRADA and this proposed work related to the mechanical technique of coating the diamond powder. Mechanical parts for the high-volume diamond powder coating process existed; however, they needed to be installed in an existing coating system for evaluation. Sputtering systems similar to the one required for this project were available at LLNL. Once the diamond powder was coated, both LLNL and Spectra Mat could make and test the Dymalloy composites. Spectra Mat manufactured Dymalloy composites in order to evaluate and establish a reasonable cost estimate on their existing processing capabilities. This information was used by Spectra Mat to define the market …
Date: June 22, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Adaptively Learning an Importance Function Using Transport Constrained Monte Carlo (open access)

Adaptively Learning an Importance Function Using Transport Constrained Monte Carlo

It is well known that a Monte Carlo estimate can be obtained with zero-variance if an exact importance function for the estimate is known. There are many ways that one might iteratively seek to obtain an ever more exact importance function. This paper describes a method that has obtained ever more exact importance functions that empirically produce an error that is dropping exponentially with computer time. The method described herein constrains the importance function to satisfy the (adjoint) Boltzmann transport equation. This constraint is provided by using the known form of the solution, usually referred to as the Case eigenfunction solution.
Date: June 22, 1998
Creator: Booth, T. E.
Object Type: Article
System: The UNT Digital Library
Beam Loading Issues for Sns Storage Ring (open access)

Beam Loading Issues for Sns Storage Ring

In the Spallation Neutron Source (SNS) storage ring, the machine cycle is dominated by the multiturn injection. Therefore, the beam loading issues are quite different from the conventional beam loading. The evolution of the particle distribution due to beam loading needs attentions. If not corrected, the beam loading effect will lead to a bunch to bucket mismatch in the injection, causing bunch leakage into the interbunch gap. The bunch leakage will increase the extraction beam loss, and lower the e-p instability threshold. On the other hand, the control of bunch leakage necessitates the beam loading factor to be small. Therefore, beam stabilities associated with the beam loading automatically satisfied. In this article, the simulation of the SNS beam loading effect (together with the space charge effect) will be presented. Same method has been applied to the PSR, where some beam loading effect is shown.
Date: June 22, 1998
Creator: Weng, W. T. & Zhang, S. Y.
Object Type: Article
System: The UNT Digital Library
Corrosion performance of structural alloys in oxygen/sulfur/chlorine-containing environments. (open access)

Corrosion performance of structural alloys in oxygen/sulfur/chlorine-containing environments.

Component reliability and long-term trouble-free performance of structural materials are essential in power-generating processes that utilize coal as a feedstock. The combustion environments encompass a wide range of oxygen partial pressures, from excess-air conditions in conventional systems to air-deficient conditions in low-NO{sub x} systems. Apart from the environmental aspects of the effluent from coal combustion, one concern from the systems standpoint is the aggressiveness of the combustion environment toward boiler structural components such as waterwall tubes and steam superheaters. The corrosion tests in this program address the individual and combined effects of oxygen, sulfur, and chlorine on the corrosion response of several ASME-coded and noncoded boiler materials exposed to air-deficient and excess-air combustion conditions. Data in this paper address the corrosion behavior of structural materials such as Type 347 stainless steel, Alloys 800, 825, 625, 214, and Hastelloy X when exposed at 650 C to excess-air combustion conditions with and without HCl. Thermodynamic calculations were made to evaluate the gas chemistries formed from coal combustion. The results of such calculations, coupled with oxygen/sulfur/chlorine thermochemical diagrams, were used to select the gas environments for the laboratory test program. Results are presented for weight change, thickness loss, microstructural characteristics of corrosion products, …
Date: June 22, 1998
Creator: Natesan, K.
Object Type: Article
System: The UNT Digital Library
Corrosion performance of iron aluminides in single- and multioxidant environments. (open access)

Corrosion performance of iron aluminides in single- and multioxidant environments.

Iron aluminide intermetallics are being developed for use as structural materials and/or as cladding for conventional engineering alloys. In addition to their strength advantages, these materials exhibit excellent resistance to corrosion in single- and multioxidant environments at elevated temperatures through the formation of slow-growing, adherent alumina scales. Even though these intermetallics develop protective oxide scales in single-oxidant environments, the simultaneous presence of several reactants in the environment (typical of practical systems) can lead to development of oxide scales that are nonprotective and that undergo breakaway corrosion, or to nonoxide scales that are detrimental to the performance of the underlying alloy. This paper describes the corrosion performance of Fe-Al intermetallics in environments that contain sulfur, carbon, chlorine, and oxygen and that are typical of fossil energy systems. Emphasis is on mechanisms of scale development and breakdown, performance envelopes for long-term usage of these materials, and approaches to modifying the surfaces of engineering alloys by cladding or coating them with intermetallics to improve their corrosion resistance.
Date: June 22, 1998
Creator: Natesan, K.
Object Type: Article
System: The UNT Digital Library
Development of structural design criteria for ITER. (open access)

Development of structural design criteria for ITER.

The irradiation environment experienced by the in-vessel components of fusion reactors such as HER presents structural design challenges not envisioned in the development of existing structural design criteria such as the ASME Code or RCC-MR. From the standpoint of design criteria, the most significant issues stem from the irradiation-induced changes in material properties, specifically the reduction of ductility, strain hardening capability, and fracture toughness with neutron irradiation. Recently, Draft 7 of the interim ITER structural design criteria (ISDC), which provide new rules for guarding against such problems, was released for trial use by the ITER designers. The new rules, which were derived from a simple model based on the concept of elastic follow up factor, provide primary and secondary stress limits as functions of uniform elongation and ductility. The implication of these rules on the allowable surface heat flux on typical first walls made of type 316 stainless steel and vanadium alloys are discussed.
Date: June 22, 1998
Creator: Majumdar, S.
Object Type: Article
System: The UNT Digital Library
Simulation Study of Three-Dimensional Laser Cooling Schemes for Fast Stored Beams (open access)

Simulation Study of Three-Dimensional Laser Cooling Schemes for Fast Stored Beams

Molecular dynamics (MD) approach is employed to study laser cooling of fast circulating beams in a storage ring. The authors compare several three-dimensional (3D) cooling methods, examining achievable minimum beam temperature. In particular, the stress is put upon the three coupling schemes, i.e. the dispersion-coupling scheme, the coupling-cavity scheme, and the tapered cooling scheme. The authors show that beam temperatures much lower than the currently achievable level could be reached with these schemes.
Date: June 22, 1998
Creator: Kihara, T.; Okamoto, H.; Iwashita, Y.; Oide, K.; Lamanna, G. & Wei, J.
Object Type: Article
System: The UNT Digital Library
RANDOM AND SYSTEMATIC FIELD ERRORS IN THE SNS RING: A STUDY OF THEIR EFFECTS AND COMPENSATION (open access)

RANDOM AND SYSTEMATIC FIELD ERRORS IN THE SNS RING: A STUDY OF THEIR EFFECTS AND COMPENSATION

The Accumulator Ring for the proposed Spallation Neutron Source (SNS) [l] is to accept a 1 ms beam pulse from a 1 GeV Proton Linac at a repetition rate of 60 Hz. For each beam pulse, 10{sup 14} protons (some 1,000 turns) are to be accumulated via charge-exchange injection and then promptly extracted to an external target for the production of neutrons by spallation. At this very high intensity, stringent limits (less than two parts in 10,000 per pulse) on beam loss during accumulation must be imposed in order to keep activation of ring components at an acceptable level. To stay within the desired limit, the effects of random and systematic field errors in the ring require careful attention. This paper describes the authors studies of these effects and the magnetic corrector schemes for their compensation.
Date: June 22, 1998
Creator: Gardner, C. J.; Lee, Y. Y. & Weng, W. T.
Object Type: Article
System: The UNT Digital Library
Iran: Arms and Technology Acquisitions (open access)

Iran: Arms and Technology Acquisitions

Report on Iran's military armaments, with initiatives to block Iran from receiving more weapons, international agreements, foreign policy, and more.
Date: June 22, 1998
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library