Student Abstracts: Physics at SLAC

Measurement of B to phi K with phi to three pi.. DAVID ATTANASIO (Tufts University, Medford, MA 02155) THOMAS SCHIETINGER (Stanford Linear Accelerator Center, Stanford, CA 94025) .
Events of the type B to phi K with phi to three pi are isolated using optimized selection criteria from the BaBar 1999-2000 Run I data set (~20 1/fb). The efficiency of these criteria are analyzed using Monte Carlo studies, enabling a comparison to the predicted occurrence of such events. The only results provided are those of the Monte Carlo efficiency study. Suggestions on completion of the study are given.

Development of Laser Beam Image Analysis System and Characterization of Flash:Ti Laser Beam. SEAN CORUM (Augustana College, Sioux Falls, SD 57197) DR. AXEL BRACHMANN (Stanford Linear Accelerator Center, Stanford, CA 94025) .
Lasers are highly important in medicine, industry, and physics. In particle accelerators, lasers are used in Photo Injectors for attaining polarized electron beams. As such, a clean beam profile is crucial to the role photo injecting lasers have in particle physics experiments. However, qualitative analysis methods of a laser beam profile (such as burn paper) are difficult and waste precious particle beam experiment time. An efficient, quantitative method of beam profile analysis is required to maintain performance of the polarized light source. A laser beam image acquisition and analysis system is developed using a CCD camera, a framegrabber card, an IBM compatible computer, and Labview (National Instruments, G programming language). The system analyzes the beam profile in continuous real-time and single shot formats. The program is versatile and calculates axis lengths, ellipticity, elliptical fit, tilt, Gaussian fit, Gaussian parameters, and 3D intensity plots. This system will be used at the Stanford Linear Accelerator Center to monitor the health of the Photo Injectors. To demonstrate the systems ability to quickly and efficiently analyze a laser beam profile, it is used to characterize thermal lensing of a single-mode and a multi-mode Flash:Ti laser beam in the Laser Development Lab. The focal range due to thermal lensing of the laser rod was observed. The system shows promise as an important tool in the diagnostics and problem solving of the particle accelerator's Polarized Light Source.

Predicting Neutralino Continuum Annihilations Using DarkSUSY . SAMEH KAMEL (Santa Clara University, Santa Clara, CA 95053) EDUARDO DO COUTO E SILVA (Stanford Linear Accelerator Center, Stanford, CA 94025) .
Physicists do not fully understand the nature of dark matter although we infer its existence from experimental observation. This project is part of the dark matter detection searches with GLAST. We are investigating one of the WIMP candidates called the neutralino, a particle predicted by the Minimal Supersymmetric Standard Model. In particular, we ran a computer simulation called DarkSUSY that predicts the signature that we expect to see in the data from GLAST that pertains to the detection of the neutralino in the galactic halo.

Prepping USA X-ray Pulsar Data for Analysis. CHRISTOPHER LAWYER (Florida A & M University, Tallahassee, FL 32307) EDUARDO DO COUTO E SILVA (Stanford Linear Accelerator Center, Stanford, CA 94025) .
The USA satellite was used to record data on several pulsars. In this project data produced by the satellite was altered so that it could be entered into a program called TEMPO. Through TEMPO several characteristics (referred to as the orbital parameters) of the pulsars will be defined. Using two well-documented pulsars, Crab and Cen X-3, the tools for analysis will be tested. If they prove to be adequate, then they will be used to study a special class of pulsars called AXPs. Through study of AXPs, it is believed that light can be shed on many of the mysteries now associated with pulsars.

Restoration of BaBar Prototype Drift Chamber. MARY MANNING (University of Virginia, Charlottesville, VA 22904) MICHAEL KELSEY (Stanford Linear Accelerator Center, Stanford, CA 94025) .
A drift chamber tracks the paths and energies of particles by measuring the charge pulse of electrons liberated by those particles as they traverse the chamber. The BaBar drift chamber (IR-2) is currently operational, but the prototype chamber (Proto II) was not. The prototype drift chamber was restored so that it could be used as a test stand for new drift chamber hardware and software. The scintillator telescope trigger system, front end electronics, high voltage supplies, water chiller, and gas system were installed, tested, and activated. Diagrams and text documentation describing the setup and running procedures for Proto II were created. Calibration and data acquisition software were modified to be compatible with two drift chamber platforms. Initial calibrations failed due to compatibility problems between drift chamber configuration maps and hardware. Subsequent calibrations were successful.

X-ray Variability in Seyfert 1 Galaxies: The Correlation Between Spectral Index and Flux. KAREN PETERSON (Yale University, New Haven, CT 06520) GREG MADEJSKI (Stanford Linear Accelerator Center, Stanford, CA 94025) .
The process of energy radiation from active galactic nuclei (AGN) is not well understood. Variability of the radiation occurs on the shortest time scales in the X-ray energy band, hence X-rays must originate nearest the power source of AGN which is suspected to be a black hole surrounded by an accretion disk. The examination in this paper of the X-ray emission of three Seyfert 1 galaxies identifies a direct relationship between spectral index and flux. This finding refutes the simplest proposed model for X-ray radiation of AGN, and an improved model with a feedback mechanism is discussed here.

Fluka Benchmark of Neutron Energy Spectra at 90-degrees. ANDREW PURYEAR (Texas A&M University, College Station, Tx 78752) SAYED ROKNI (Stanford Linear Accelerator Center, Stanford, CA 94025) .
This paper presents a comparison between results of FLUKA particle interaction and transport code benchmarked with experimental measurements of neutron energy spectra at 90-degrees produced by the irradiation of various targets by a 2.04-GeV electron beam. Neutron fluence, integrated yield, and time of flight calculated by FLUKA are compared with experimental results. Also, the effects of various components of the experimental set up on neutron energy spectra are studied.

Improving the Tune Monitor of PEP-II Asymmetric B Factory. JOLENE ROBIN (University of New Orleans, New Orleans, La 70148) ALAN FISHER (Stanford Linear Accelerator Center, Stanford, CA 94025) .
PEP-II is a high luminosity 2.2-kilometer circumference collider in which 9-GeV electrons in the high-energy ring collide with the 3.1 GeV positrons in the low-energy ring to produce B and B-bar meson pairs for the study of CP violation, an asymmetry between matter and antimatter that may account for the predominance of matter in the universe. One of the most important diagnostic systems in PEP-II is the tune monitor. The PEP-II tune monitor was evaluated and redesigned to accomplish several tasks. First, the new tune monitor will have more sensitivity (lower noise floor); this will be accomplished by redesigning the downconverter. Second, an additional measurement plane (in the z or longitudinal direction) so that the synchrotron tune using the sum of the four buttons can be analyzed. Third, another spectrum analyzer, with a much higher bandwidth (at least 10 GHz) so that physicists can look for special spectral features at high frequencies that have, up until now, been unavailable. Last, a way for a computer to track and record changes to the tune automatically. A component called a lock-in amplifier was evaluated and shows promise.

Microwave Calibration Device. ALEXANDER SEKON (UCSC, Santa Cruz, CA 95062) JOSEF FRISCH (Stanford Linear Accelerator Center, Stanford, CA 94025) .
The Next Linear Collider Test Accelerator requires accurate calibration of X-band (11.424GHz) microwave signals. In this project we built a prototype of a device to calibrate power loss across low power components of the Next Linear Collider Test Accelerator. This device measures the output power of a Gunn diode using a detector as the receiver. These measurements are taken by reading the output of the detector with a voltmeter or oscilloscope. This device can be operated for hundreds of hours on 9 volt batteries and is small enough to hold in your hand.

Designing a Superfluid Helium Test Dewar for Testing SQUIDs. CHARLEZETTA WILSON (Howard University, Washington, DC 20001) DR. JOHN WEISEND (Stanford Linear Accelerator Center, Stanford, CA 94025) .
A large superfluid helium test dewar was designed and constructed. The dewar will be used in the near future for testing Superconducting QUantum Interference Devices (SQUIDs). The goal is to test the SQUIDs at 4.2 K and 2 K. The dewar's final temperature was <0.05 K warmer than the superfluid goal, but is readily functional at 4.2 K. Changes in design are currently being considered. The SQUIDs being tested will be used in a later experiment at the Thomas Jefferson National Laboratory in Newport News, VA. >