Instrumentation Commons^™

Validation Of Electromagnetic Shower Development In A Reduced Alice Focal-E Detector Model Using Geant4, Isaac Lara Romo

Physics

This project focuses on the preliminary simulation of a reduced FoCal-E detector model for the ALICE experiment at CERN. Beamline tests were simulated using an electron gun at various incident energies, and the results were compared with those of the FoCal group. The longitudinal charge deposition per sensor layer was compared between the two setups to verify that the reduced model exhibited expected calorimeter behavior. Additionally, the transverse signal across the high-granularity sensor layers was examined to determine whether the reduced model reproduced the expected lateral development of electromagnetic showers. The results obtained from these measurements show that the reduced …

Modeling Cherenkov Light Detection Timing For The Very Energetic Radiation Imaging Telescope Array System, Keilan Finn Ramirez

Physics

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an array of four 12-meter telescopes which use the Imaging Atmospheric Cherenkov Technique to conduct high-energy gamma-ray astronomy. VERITAS detects magnitude and location information associated with Cherenkov light, and uses this information to indirectly observe gamma-rays through a software reconstruction process. VERITAS also records timing information corresponding to Cherenkov light detection, and this additional information could theoretically be incorporated into the reconstruction process to improve the accuracy of gamma-ray observations. The first step to including timing information is to understand when Cherenkov light detection would be expected from a known …

Probing The Fitting Accuracy Of Active Galaxy Spectra, Aaron T. Line

Physics

Prior to this study, Dr. Vardha N. Bennert and collaborators selected a sample of ~100 local active galaxies to study the relationships between black hole mass and host galaxy properties. The broad Hβ width is necessary to determine black hole mass. This value is determined using a spectral decomposition code was scripted in IDL by Dr. Daeseong Park. The script fit spectral features and collected data for properties such as width of emission lines and continuum contribution percentages. The results were logged for further analysis.

To probe the accuracy of the fitting process, artificial spectra were created and fitted to …

Counting Photons To Calibrate A Photometer For Stellar Intensity Interferometry, Jason Chew

Physics

We use a telescope and photometer to observe stellar photons and measure the rate of observed photons. Based on intensity spectra from the Spectrophotometric Catalogue of Stars, we also predict expected values for the photon rates, which we compare to our measurements. From this comparison, we measure the local optical depth to be τ = 0.60±0.25, a reasonable value. We find that our predictions are directly proportional to our measurements by a factor of 0.98 (+0.02, -0.27) . The similarity between our measurements and expectations shows that we are able to both predict and measure photon rates with accuracy.

Optimization Of The Veritas Orbit-Mode Tracking Pattern, Joshua Allen

Physics

Gamma-ray Bursts (GRBs) have not been detected at TeV energies. Detection with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) would open a new window into GRB science. In this paper, we optimize an orbit mode tracking method to search for a GRB at a location provided by the FERMI Gamma-ray satellite. Using Matlab we modeled the orbit tracking pattern. Then we found the optimal offset radii and tracking speed for the telescope to form a uniform image exposure. To optimize the pattern, the model accounts for the maximum 1°/s speed of the telescope’s tracking motors and the camera’s …

Gamma-Ray Spectroscopy: Meteorite Samples And The Search For 98tc, Kristopher L. Merolla

Physics

The focus of this project is low-count-level gamma-ray spectroscopy on meteorite samples in search of a particular isotope of Technetium (98Tc), which according to stellar theory, should be present in the universe. The spectral lines for 99Tc have, however, been observed in S-, M-, and N- type stars, which makes finding 98Tc created naturally a possibility, and thus a search can be justified.