Adapting devices for a beamline and EXAFS measurement. TIM VANDERLEEST (Chicago State University Chicago, IL 60628) DR. JUSTIN AKUJIEZE (Argonne National Laboratory, Argonne, IL, 60439)

The prototype circuitry for a remote shutter control system was succsessfully designed, created and tested. In addition, a schematic of the circiutry has been created and sent for professional fabrication. This system is needed for control of the intense synchrotron beam that is used in a beamline. Secondly, a specialized sample mount for thin-film EXAFS (Extended X-ray Absorption Fine Structure) measurement was designed and built. The uniqueness of the sample mount is in that the sample can be rotated to perform angle-resolved EXAFS measurements while the sample remains in the beam path.

Effects of Superhard Nanocomposite Coatings on Friction Between Piston Rings and Cylinders in Automobile Engines. JEFF BAYERS (Washington University in St. Louis St. Louis, MO 63105) DR. GEORGE FENSKE (Argonne National Laboratory, Argonne, IL, 60439)

With rising gas prices and ongoing disputes over foreign oil sources, improving fuel economy is a task of great importance. A primary weakness in fuel efficiency in automobiles occurs in engine pistons: as piston rings rub repeatedly against the inside of the cylinders, the resulting friction hinders their movement and consequently excess fuel is impractically expended. Furthermore, this repetitive rubbing can gradually cause wear in both the cylinder liner and the ring, thereby weakening both and decreasing the engine's operating efficiency. Here in the tribology department, which focuses on the physical concepts of friction, wear, and lubrication, we have been testing a recently developed Super Hard NanoComposite coating (SHNC), a wear-resistant lubricant designed to reduce friction between surfaces in contact. Using a High Frequency Reciprocating Rig (HFRR), we can simulate the rubbing of a ring against a liner while measuring the resulting friction, allowing for in-situ testing of the new coating. Because conducting tests using a model engine would be too costly and difficult to monitor, all tests are being performed with the HFRR. The coated liner is tested with a variety of commercial motor oils as a means of determining chemical interaction between the coating and the oils that might also occur in practical environments. On liners for which the coating has been applied and allowed to wear in through initial runs of the HFRR, marked reductions in friction and coefficient of friction have been measured. Friction shows the greatest reduction when the HFRR is operated at higher speeds, although the tests have not exceeded 360 rpm. Comparing different amounts of a single oil type shows relatively insignificant differences between the different quantities of oil. All tests are also conducted with different speed transitions. Data is taken at individual speeds and again as the rig accelerates and decelerates to further simulate actual Ring-On-Liner (ROL) interaction. Further testing will be conducted using different liner and ring combinations such as: both uncoated, coated ring and uncoated liner, and both coated. These tests work in conjunction with other simulations of surfaces in contact to determine the most efficient contact area between two surfaces.

EXAFS measurements of Doped Cadmium Sulfide Methods of Analysis. VIRGINIA HAYES (Chicago State University Chicago, IL 60636) DR. JUSTIN AKUJIEZE (Argonne National Laboratory, Argonne, IL, 60439)

Cadmium sulfide is a photoconductor, radiation detector, and serves as a photovoltaic cell. It exits in two structures wurtzite and zinc blend type cubic. The wurtzite structure is an ABC structure, which makes it hexagonal. The zinc blend cubic structure is the ABA structure and is also the one being studied. Manganese sulfide also shares the same structure as cadmium sulfide. The focus of this project is to measure the resulting chemical environment of the compound cadmium sulfide when manganese is doped for cadmium in the CdS matrix. In order to do this we carried out fluorescent EXAFS Spectroscopy because of a very high absorption and low transmission of radiation. EXAFS Spectroscopy is a way to determine the local chemical environment of an element (except the lightest) in a structure. The nano materials were of different sizes (18, 23, and 30 ) and have varying amount of manganese content There were two variables in this study, (thickness of sample, and Mn content) and samples were run ten times each. Further analysis using the Artemis software is required in order to obtain more information from these data.

Exploring Gold Nanoparticle Monolayers with a Langmuir Trough and X-rays. JESSICA MURRAY (Eastern Illinois University Charleston, IL 61920) DAVID SCHULTZ (Argonne National Laboratory, Argonne, IL, 60439)

Gold nanoparticles show the possibility of being applicable in many different areas of technology due to the particles' collective and individual behavior and characteristics. By examining the nanoparticles' behavior and characteristics, more distinctive and unique qualities of nanoparticles may be known and used to benefit society. However, the difficulty in researching nanoparticles is finding the right conditions to create a solution of nanoparticles that would yield useful experimental data on the behavior of the solution. The purpose of this experiment is to find the conditions to create a uniform gold nanoparticle monolayer. The features of gold nanoparticle films on the surface of pure water were studied with use of a Langmuir trough, optical microscope and an x-ray liquid surface spectrometer. By varying the conditions used for sample preparation, it was found that for every 1 ml of gold nanoparticle solution, 12 µl of dodecanethiol needs to be added to create a uniform film. Also observed was that the temperature of the solution needs to be increased to 37 C while compressing the film to prevent thiol bubbles from sitting on the surface of the film.

Gas-Filled Recoil Separation of Heavy Ions at Intermediate Energies. MATTHEW STERNBERG (University of Oregon Eugene, OR 97403) GUY SAVARD (Argonne National Laboratory, Argonne, IL, 60439)

Current capabilities for the capture of fusion recoils produced at the Argonne Tandem Linear Accelerator System (ATLAS) and used for mass measurements at the Canadian Penning Trap are limited. A method has been developed in which a large range of recoil products at various energies could be efficiently separated from the primary beam. Simulations suggest that recoil products could be captured with initial angles of divergence as large as 12 degrees, improving the current efficiency by as much as 1000%. Design and construction of the proposed apparatus are currently underway at Argonne National Laboratory. The current laboratory setup is capable of capturing reaction products emitted at angles up to 4 degrees off axis. In the majority of reactions recoil products are emitted at angles within 4 degrees of the primary axis. However, there are many desirable reactions, such as those in which alpha particles are emitted, where the majority of products diverge from the primary axis at angles in excess of 4 degrees. The use of a large bore solenoid magnet has been investigated as a means of capturing a larger range of recoil products. A Monte Carlo simulation has been developed to model the transport of ions through a gas-filled solenoid magnet and different means of disposing of the primary beam have been investigated.

Investigating the Frictional Effects of SuperHard Nano-Composite Films and Laser Texturing. MARK WHEELER (Amherst College Amherst, MA 01002-5000) GEORGE FENSKE (Argonne National Laboratory, Argonne, IL, 60439)

Tribology is often applied to the study of the inner workings of automotive combustion engines because small reductions in engine friction could mean savings of several million barrels of gas nationwide and improvements to engine life. Our experiments are conducted with commercial Mobil-1 10W30 formulated motor oil on a "High Frequency Reciprocating Rig" that uses segments taken from stock engine liners and stock engine rings. Using actual pieces of engine increases the realism of the experiments but also introduces alignment issues that can make exactly repeating experiments difficult. A reciprocating rig also imitates the motion of a piston engine, though at much lower rpm. The rig runs from 15 to 300 rpm and delivers loads of 0 to 250N. Our first experiment was the testing of a liner coated with a recently developed "Super-Hard Nano-Composite" with a stock ring. The SHNC sample was tested against a stock sample at room temperature, after a three hour bake in 150ºC oil and after a three hour run in 150ºC oil. The heated and the heated while running experiments were conducted to test the effects of tribofilms that may be formed by the Mobil-1 oil's additives either thermally or tribologically. Initially the SHNC liner performs about 30% worse than the stock and when baked or baked while running about performs about 20% worse. This contradicts previous experiment on a pin on flat apparatus which showed a roughly 60% improvement over stock after several hours of running. As predicted, wear on the SHNC surface is negligible compared to stock. Our second experiment tested three samples with half of their surface laser textured. The laser texturing in these samples is a pattern of small dimples 2, 5, and 8 microns deep respectively, 100 microns in diameter, and spaced center-to-center by 200 microns. The half textured surface allows for a comparison of the performance versus a stock baseline in every stroke of data. The first and most obvious result from these liners is clear indication that the dimpled surfaces need wearing in (or possibly polishing). Microscope examination reveals that the dimpling process creates a slightly raised ring around the dimple. This raised area wears down with a few hours use and friction is reduced but it has not yet been explored how much wear is optimal. Despite all the dimpled liners performing worse than the stock, the 5 micron dimple depth outperformed the 2 and 8 micron deep liners slightly before and after wear.

Ion Beamstop Design for a High Precision Mass Measurement System. DAVID DANAHER (Monmouth College Monmouth, IL 61462) GUY SAVARD (Argonne National Laboratory, Argonne, IL, 60439)

The precise mass measurement of ions is the main objective of the Canadian Penning Trap (CPT) collaboration at Argonne National Laboratory. The mass measurements require a beam from the Argonne Tandem Linear Accelerator System (ATLAS) to fuse with a target to create the desired reaction products, which diverge due to alpha decay and are refocused for later measurement. Depending on the components of the reaction, some reactions have particles with much greater divergence angles than others. Some measurements are limited by ions displaced at angles greater than what are able to be collected by the current system. A new beamline is being added to collect products with greater divergence angles (±9º). Much of the beam, however, passes through the target without interaction, and will overwhelm the data of the reaction products if left to continue through the system. The method for stopping the beam in the current system is not applicable to the new beam line, so a new solution is required. We developed a system that allows ±2.5º to ±4.5º of beam to be blocked while still allowing most of the desired reaction products to continue through the system. The new beam stop will be built and placed in the new line which is still under construction. With the new beamline in place at the ATLAS facility, the CPT collaboration will no longer be limited to reactions which produce the desired nuclides emerging with low divergence angles. The effect of the new beam line, in conjunction with the beam stop, will be to permit more precise measurements in some cases and make other measurements possible in cases that were not possible before.

Measuring the Magnetic Field of the ECR-2 Magnet at ATLAS and its Effect on Charged Particle Beams. CACEY STEVENS (Southern University and A&M College Baton Rouge, LA 70813) ELIANE LESSNER (Argonne National Laboratory, Argonne, IL, 60439)

The purpose of the Argonne Tandem Linear Accelerator System (ATLAS), a particle accelerator at Argonne, is to generate beams of heavy ions for interaction with matter. The charged particles are generated by the Electron Cyclotron Resonance (ECR) source, accelerated by electric fields from radio frequency cavities, and focused or bent by magnets. The current induced magnetic field within a magnet exerts a force on the beam particles which changes their direction of motion. A dipole magnet at ATLAS, known as the ECR-2 analyzer magnet, focuses in both planes due to edge angles of 29.4 degrees and bends an ideal beam 90 degrees to be sent to various experimental areas. In this context, we measured the ECR-2 field to determine its effects on the beam trajectory at different points in the magnet. Using a Hall probe, the magnetic field was recorded by the gauss meter and plotted according to the Cartesian coordinate system. The trajectories of oxygen, krypton, and lead ion beams through ECR-2 are compared to trajectories through an ideal sector dipole using simulations performed on the software program, Particle Beam Optics Laboratory. The simulation of an ideal sector magnet had a uniform magnetic field of 1021 gauss to agree with the maximum value of the magnetic field measured in the ATLAS dipole, 1021 gauss. The plots of the ECR-2 analyzer magnet show gradual decrease in the magnetic field away from the center of the magnet. The comparison of the ideal sector to the ECR-2 magnet shows that the ECR-2 focuses more significantly in the x- and y-planes. In addition, y' changes in the ECR-2 analyzer magnet due to edge focusing effects.

Modeling and Visualizing the Particle Beam in the Rare Isotope Accelerator. CHRISTOPHER ROSENTHAL (Illinois Institute of Technology Chicago, IL 60616) BELA ERDELYI (Argonne National Laboratory, Argonne, IL, 60439)

Argonne National Laboratory is actively pursuing research and design for a Rare Isotope Accelerator (RIA) facility that will aid basic research in nuclear physics by creating beams of unstable isotopes. Such a facility has been labeled as a high priority by the joint Department of Energy and National Science Foundation Nuclear Science Advisory Committee because it will allow more study on the nature of nucleonic matter, the origin of the elements, the Standard Model, and nuclear medicine. An important part of this research is computer simulations that model the behavior of the particle beam, specifically in the Fragment Separator. The Fragment Separator selects isotopes based on their trajectory in electromagnetic fields and then uses absorbers to separate particles with a certain mass and charge from the rest of the beam. This project focused on the development of a multivariate, correlated Gaussian distribution to model the distribution of particles in the beam as well as visualizations and analysis to view how this distribution changed when passing through an absorber. The distribution was developed in the COSY INFINITY programming language. The user inputs a covariance matrix and a vector of means for the six phase space variables, and the program outputs a vector of correlated, Gaussian random variables. A variety of random test cases were conducted in two, three and six variables. In each case, the expectation values, variances and covariances were calculated and they converged to the input values. The output of the absorber code is a large data set that stores all of the variables for each particle in the distribution. It is impossible to analyze such a large data set by hand, so visualizations and summary statistics had to be developed. The first visualization is a three-dimensional graph that shows the number of each isotope present after each slice of the absorber. A second graph plots any of the six phase space variables against any of the others to see the change in the beam's distribution. Also, the expectation values, variances and covariances of the phase space variables were calculated after the absorber. The distribution that models the particle beam gives the variability that physicists need to simulate many different situations in the Fragment Separator. The statistics and visualizations will allow quick analysis of the particle beam. Both of these developments will contribute to the overall viability of the RIA proposal.

Optimization of Electronics for "Clover" Germanium Detectors. CHAD HUIBREGTSE (Beloit College Beloit, WI 53511) C. J. LISTER (Argonne National Laboratory, Argonne, IL, 60439)

Gamma ray detectors are a necessary tool for nuclear physics, and by examining gamma radiation we may more clearly identify the inner workings of the nucleus and further the boundaries of science. Currently the best gamma ray detectors operate by using germanium semiconducting crystals. Argonne National Laboratory has recently acquired three semiconducting Ge "Clover" detectors that each contain four germanium crystals. In order to get the best use from these detectors it is necessary to run several diagnostic tests on them to find their ideal operating settings. The Clover detectors were calibrated for both energy resolution and timing coincidence to prepare them for use in future experiments.

Progress Toward a Liquid Lithium Target and Electron Stripper for the Rare Isotope Accelerator. IAN GUERASSIO (Colorado School of Mines Golden, CO 80401) JERRY NOLEN (Argonne National Laboratory, Argonne, IL, 60439)

The proposed Rare Isotope Accelerator (RIA) facility will utilize new fragmentation targets and electron strippers that can survive the expected 200 kW of beam power. Liquid lithium offers a unique solution to the problem of dissipating the beam energy by acting as both target and coolant. A flowing, liquid lithium target with Beryllium windows could be used to create radioactive beams in the mass range of oxygen to calcium. A windowless target at the Alkali Metal Experiment (ALEX) facility at Argonne National Laboratory (ANL) already demonstrates that a liquid lithium target can maintain usability in a 200 kW beam. Current experiments are attempting to create a flowing liquid lithium thin film for use as a stripper material.

RIA Rotating Foil Stripper Design. MICHAEL BERTOLLI (Colorado School of Mines Golden, CO 80401) JERRY NOLEN (Argonne National Laboratory, Argonne, IL, 60439)

Development of the next generation of accelerator facilities, the Rare Isotope Accelerator (RIA), is underway. It's construction will lead to fundamental breakthroughs in the study of unstable nuclei and nuclear physics. In order achieve the goals of RIA, a method of proper cooling of integral beam strippers in necessary. Using a pendulum swinging, rotating foil wheel it may be possible to reach the required cooling rates. Several possible cam designs that can be used to cause the pendulum motion are analyzed in this paper. Mathematical models of of the cam designs have been developed and can be used to determine the most desirable configuration. The optimal design depends on several factors, including increasing smoothness of rotation and reducing friction. The disadvantages of each design are detailed, with the cylindrical cam appearing as a strong design option. Design of the foil beam strippers, while integral, is only a small part of the massive collaboration working on RIA in the drive to reach the next level of experimental nuclear physics.

Sputter Yield Measurements and Analysis of EUV Lithography Collector Mirrors under Low Energy Particle Bombardment. EDWARD HINSON (Middlebury College Middlebury, VT 05753) J.P. ALLAIN (Argonne National Laboratory, Argonne, IL, 60439)

In extreme ultraviolet lithography (EUVL) environments, both laser produced plasma (LPP) and gas discharge produced plasma (GDPP) configurations face serious problems regarding component lifetime and performance under particle bombardment, in particular collector mirrors. For both configurations, debris, fast ions, fast neutrals, and condensable EUV radiator fuels (Li, Sn) can affect collector mirrors. In addition, collector mirrors are exposed to impurities (H, C, O, N), off-band radiation (depositing heat) and highly charged ions leading to their degradation and consequently limiting 13.5 nm light reflection intensity. In an effort to address these issues, the IMPACT (Interaction of Materials with charged Particles and Components Testing) experiment at Argonne National Lab involves in part the calculation of sputter yields on precision optical mirror surfaces. For this project, this entails: a numeric calculation of the QCM collected fraction (O) for various conditions in which yield measurements were taken, an analysis of temperature-dependent effects in QCM response to particle deposition, and collection of sputtering data for various impinging singly-charged inert gases (e.g. Xe, Ar) and radiator fuels (Sn, Li), and calculation from this data resultant sputter yields on glancing incidence mirrors (Ru, Pd, Si/Mo) at bombardment energies in the 100-1000 eV range at room temperature.

Sputter Yield Measurements and Analysis of EUV Lithography Collector Mirrors under Low Energy Particle Bombardment. EDWARD HINSON (Middlebury College Middlebury, VT 05753) JEAN PAUL ALLAIN (Argonne National Laboratory, Argonne, IL, 60439)

In extreme ultraviolet lithography (EUVL) environments, both laser produced plasma (LPP) and gas discharge produced plasma (GDPP) configurations face serious issues regarding component lifetime and performance under particle bombardment, in particular collector mirrors. For both configurations, debris, fast ions, fast neutrals, and condensable EUV radiator fuels (Li, Sn) can affect collector mirrors. In addition, collector mirrors are exposed to impurities (H, C, O, N), off-band radiation (depositing heat) and highly charged ions leading to their degradation and consequently limiting 13.5 nm light reflection intensity. This work involves the calculation of sputter yields on optical mirror surfaces in the IMPACT (Interaction of Materials with charged Particles and Components Testing) experiment at Argonne National Lab. Because of the low ion energies used to cause sputtering in IMPACT, measurements taken with a Quartz Crystal Microbalance - Dual Crystal Unit (QCM-DCU) must be cleared of background noise more thoroughly than is necessary in other of its applications. This project focused on identifying and removing noise introduced by various ambient temperatures T, as well as the rate of temperature change, dT/dt. In addition, the method of calculating sputter yields was largely automated and its accuracy improved by integrating experiment-specific TRIM-calculated distributions and constants into the yield equation, in place of previous general use approximations.

Structural Study of 2-Quasiparticle States in ²⁵⁴No. JEREMY CHAPMAN (Syracuse University Syracuse, NY 13210) TENG LEK KHOO (Argonne National Laboratory, Argonne, IL, 60439)

Heavy nuclei are prone to spontaneous fission. A large shell-correction energy provides a sizeable barrier against fission in some superheavy nuclei, e.g. ²⁵⁴No. Isomers in ²⁵⁴No were studied in a ²⁰⁸Pb(⁴⁸Ca,2n) reaction to provide data on single-particle energies and pairing. Germanium Clovers detected gamma rays, and a Double-sided Silicon Strip Detector (DSSD) detected electrons and alpha particles. Gamma ray intensities and branching ratios were detected. Gamma rays were found at 53keV from the (7^- or 8^-) isomer to the 7⁺ state in a 2-quasiparticle band with K^p = 3⁺. Gamma rays were also found at 842keV and 944keV from the 3⁺ band head to the 4⁺ and 2⁺ states respectively, in the ground state band. The decay percentage is 15% and 85% respectively.

The Theoretical Basis of an EXAFS Measurement of Mn Doped CdS. CHINEDUM IBEABUCHI (Chicago State University Chicago, IL 60628) JUSTIN AKUJIEZE (Argonne National Laboratory, Argonne, IL, 60439)

Cadmium Sulfide is valuable in its use in sensors, optoelectronic devices, and solar cells. Cadmium sulfide was doped with manganese to observe if theses properties would remain. Due to the smaller size of manganese, it was expected that the structure of cadmium sulfide would be distorted when doped with manganese. This could possibly change the structure from cubic to wurtzite. It was also expected that the structure of cadmium sulfide would change the energy level excitation occurrence. To probe the structure of cadmium sulfide extended x-ray absorption of fine structure (EXAFS), spectroscopy was performed. This paper presents the theoretical concepts behind various EXAFS fitting software. The absorption edges of our samples were typically around 6.5 KeV indicating the presence of Mn. Further analysis using enhanced software will be carried out in due course. When such analysis is concluded, the oxidation state of Mn and bond lengths of immediate neighbors will be obtained.

Understanding Helium Burning in Stellar Evolution Through Nuclear Physics. DAVID KAHL (Beloit College Beloit, WI 53511) ERNST REHM (Argonne National Laboratory, Argonne, IL, 60439)

The project undertaken by the experimenter is located at ATLAS (Argonne Tandem-Linear-Accelerator-System) and is focused on preparation and calibration of an ion chamber for a future experiment. As a summer intern, I ran the day-to-day documentation, data collection and on-line data analysis of an ion chamber designed to study the astrophysical important reaction ¹²C(α, γ)¹⁶O. We study this reaction by looking at the β-delayed α decay of ¹⁶N. This essay will begin by describing the importance of the ¹²C(α, γ)¹⁶O reaction to stellar evolution, as well as how we plan to study the reaction in the coming months. From there, our experimental technique will lead the reader to an understanding of our particular setup, as well as the reasoning behind our chosen configuration. It will then follow logically what components of our detection apparatus require thorough testing, the results of that testing, and specifically how the author has contributed to this ongoing research.

Unusually large magnetostriction effect at room temperature in A-site ordered perovskite manganites. ANNE STYKA (University of Illinois at Chicago Chicago, IL 60607) YANG REN (Argonne National Laboratory, Argonne, IL, 60439)

The temperature and magnetic field-dependent structural properties of the half-doped A-site ordered manganites RBaMn2O6 (R = Pr, Nd, Pr_½Nd_½) have been studied using high-resolution high-energy X-ray powder diffraction. The compounds are ferromagnetic at room temperature and antiferromagnetic at lower temperatures. It is found that the lattice parameters of the crystal structure are very sensitive to applied magnetic fields in the ferromagnetic states, while the antiferromagnetic state is unchanging. An unusually large magnetostriction effect is obtained at room temperature, with the magnetostriction of the order of 1200 microstrain. The observed phenomena is explained in terms of a change in orbital occupancy of the eg electrons from the d{x²-y²} state to the d{3z²-r²}induced by external magnetic fields.