B.A. of Physics and Astrophysics
University of Colorado, Boulder
Professional Research Assistant with CU's Supersymmetry(SUSY) Group
My undergraduate thesis discusses how well CU's proposed electromagnetic calorimeter (ECAL) design for the International Linear Collider (ILC) can separate and measure incident photons due to the decay of neutral pions:
Thesis work: "Development of Calorimetric Techniques for Detectors in the Search for SuperSymmetry"(HTML)
(pdf form) or (PowerPoint Presentation)
This paper descibes our ECALdesign and also details the creation of an algorithm I wrote to identify the positions and energies of the photons observed by the ECAL when neutral pion decays occur. Since the completion of my thesis, this algorithm has been improved upon - a new paper is in the works. It can now identify the incident positions and energies well enough that the momentum of the parent pizero can be reconstructed to within 2% of it's actual value with standard deviation range of 0.3%-2.4% depending on the energy of the cluster.
I have recently taken over the work of Elliot Smith and Keith Drake, evaluating the efficiency of silicon photomultipliers (SiPMs) to be implemented in our electromagetic calorimeter design, which includes one SiPM energy read-out for each 5x5 cm scintillator tile. Ideally, several such tiles will be aligned in a cyllindrical fashion around a beampipe ~1m in radius. These scintillator tiles will be stacked with alternating layers offset, forming a brick-like pattern 40 layers tall, to deliver an effective resolution equal to that which could be attained by using 2.5 x 2.5 cm tiles.
Johnathan Varkovitzky and I are currently inventigating the ideal thickness for these scintillator tiles. We are now analyzing the SIPM signal read-out strength by measuring cosmic rays in a set-up that features a scintilltor tile that is 5 cm thick. Previous measurements were made with an identical tile 7mm thick.
Email: tdunn[at sign here]pizero.colorado.edu
On Campus: Duane Physics Building, room E222
Campus mail: Campus Box 390, Boulder, CO 80309