Student Abstracts: Physics at ANL

Analysis of Creep Cavitation in Silicon Nitride Using Anomalous Ultra-Small-Angle X-ray Scattering. JONATHAN ANDREASEN (Illinois State University, Normal, IL 61790) DR. GABRIELLE LONG (Argonne National Laboratory, Argonne, IL 60439) .
The goal of this project is to investigate the deformation of silicon nitride at high temperatures. Silicon nitride is a ceramic used in the construction of gas turbines. It has excellent mechanical properties at high temperatures but deforms under tensile creep when put under a load. This tensile creep limits the application of this material. In commercial materials, the volume fraction of voids that are produced increases linearly with the amount of strain placed on the samples. Secondary phases (rare-earth oxy-nitrides) have been added to the silicon nitride in an effort to limit the creep behavior. Using Anomalous Ultra-Small-Angle X-ray Scattering (A-USAXS), the volume fractions of both the voids and secondary phase in deformed samples of silicon nitride can be measured. To find the volume distributions of the voids and secondary phase, the data from the X-ray scattering must first be reduced, and then analyzed. To find the volume distributions of the voids and the secondary phase, a C computer program was written. For all samples, the volume distributions of both the voids and the secondary phase were found. The results agree with the theory that the volume fraction of voids increases linearly with strain for the Yb-containing material. The ceramic containing Lu oxy-nitrides had very little strain measured and A-USAXS confirmed the small amount of voids present in this material.

. WINSTON DASILVA (Morgan State University, Baltimore, MD 21251) VINCE NOVICK (Argonne National Laboratory, Argonne, IL 60439) .

ATLAS / RIA Website. TERESA HASLINGER (Richard J. Daley College, Chicago, IL 60629) DR. FRANK E. MOORE (Argonne National Laboratory, Argonne, IL 60439) .
During my summer internship at Argonne my assignment was to work on a new website for the Physics Division. This website has two parts. For the first part, this website includes the ATLAS Accelerator Facility (ATLAS) that needed to be updated. ATLAS is a system that accelerates ions for the production of heavy ion beams. Such beams are valuable in the understanding of basic nuclear physics. Dr. Frank Moore, my mentor, drew the site plan from which originated the first part of the website. The information that was used for this site was taken from many sources in the Physics Division. The second part of the website includes a proposed facility - the Rare Isotope Accelerator (RIA) - which Argonne is bidding for. RIA produces and accelerates beams of short-lived nuclei, which will help to understand nuclei far from stability. The information is basically the same (the information is mostly taken from the original site), but the design is much improved. For both parts of the website, images and text were used. The use of images in combination with text made it possible to make the information clear and easy to understand for the reader. The implementation of this site is at www.phy.anl.gov/atlas/index.html .

Tile Calorimeter and MySQL Database. TOM KOTSAKOS (Wilbur Wright College, Chicago, IL 60634) DR. BOB STANEK (Argonne National Laboratory, Argonne, IL 60439) .
A Large Hadron Calorimeter is being built at CERN in Geneva, Switzerland. This collider will be able reach energies of seven TeV. Many experiments require high energy. One of the main goals is to discover the Higgs Boson, which can be created by a high-energy collision. One section of the Tile Calorimeter is being built at Argonne National lab. The construction and testing data are being put into a database using MySQL as the RDBMS. The Tile Calorimeter measures the energy of particles that are generated by the collision of the protons. When a particle goes through a tile, it sends a photon down the fiber to be amplified and read. The database works by joining tables on unique keys. Any other secondary program can utilize the output of a query. The database will be accessible through the web with a graphical interface and forms for search criteria. When the LHC and ATLAS are completed, the database will have further use in integrating with new data or other databases.

Automation of the Vacuum System in Area II of the ATLAS Super-Conducting linac. DANIEL LASCAR (University of Chicago, Chicago, Il 60637) GUY SAVARD (Argonne National Laboratory, Argonne, IL 60439) .
The system of vacuum pumps and valves that exists throughout area II of the ATLAS was becoming more and more complex to control manually. Furthermore, simply pumping down the system was becoming a very cumbersome, time consuming, and increasingly specialized task. With increasing beam-time being wasted, automation of the vacuum system became a necessity. To do this it was decided a Programmable Logic Controller (PLC) should be used to control and monitor the system. With the PLC, it was possible to run the system both automatically and manually via the use of buttons and switches. In addition, error localization could be performed by the PLC rather than the having to test each possible failure when one part of the target area went down. To automate this system, new pneumatic valves and thermocouples had to be ordered, a procedure for the operation of the vacuum system had to be constructed, a program in the ladder logic of the PLC had to be written, and a board containing both the manual controls for the syst em and the LED's that would indicate the status of the system had to be designed and constructed.