Steve Magill
Physicist Stephen Magill (HEP) and Postdoctoral Researcher Lisa Goodenough (HEP) will discuss their Laboratory-Directed Research and Development (LDRD) sponsored work at the LDRD Seminar Series presentation Tuesday, Oct. 24, 2017. “Directional Dark Matter Detection using Columnar Recombination” begins at 12:30 p.m. in the Building 203 Auditorium. All are welcome to attend.
Abstract
As we can observe, our universe consists of matter in the form of stars, planets, dust and even smaller particles, e.g., neutrinos. However, all of the observed matter in our universe makes up only ~5 percent of its total mass/energy. It is evident that ~25 percent of the makeup of our universe is in the form of “dark matter” that we see only by gravitational effects.
One of the leading dark matter candidates is the weakly interacting massive particle (WIMP). WIMPS are a relic of the Big Bang with characteristically weak interaction strength and a wide range of allowed masses. WIMPs should be detectable via very small cross section weak interactions with atomic nuclei, which recoil when struck. The recoiling nucleus will deposit energy by exciting and ionizing the detector medium, resulting in a densely ionized track. In dark matter detectors with solid or liquid targets, the length of the recoil track is much less than 1 micron, which makes it extremely difficult, if not impossible, to determine the recoil’s direction. There are some dark matter detectors designed to detect both the energy and direction of the recoiling atom using a rarefied gas target, but at the low pressures necessary for detectable recoil track lengths, the target mass is orders of magnitude too small to collect WIMP interactions.
Lisa Goodenough
What is described in this presentation is a novel technique designed to detect both the recoil energy and its direction resulting from a WIMP-nucleus interaction. This method, if successful, would meet the large target requirements by using a high-pressure Penning gas mixture and would use the effect of columnar recombination to determine directionality — all in one dark matter detector. Results from our LDRD initial studies of a particular gas mixture will be described along with suggestions for future investigations.
Biography
Stephen Magill is an experimental particle physicist in the High Energy Physics (HEP) Division with expertise in calorimetry and electromagnetic particle interactions in matter. He has served for many years as a member of the International Advisory Committee for the Calorimetry in High Energy Physics international conferences. His physics interests include jet physics with expertise in extreme QCD, particle reconstruction with expertise in Particle Flow Algorithms for use in future collider experiments, and in understanding basic properties of neutrinos – their possible Majorana nature, the value of neutrino masses and whether CP-violation is present. He pioneered analysis leading to studies of alternative parton evolution schemes in QCD while on the ZEUS Deep Inelastic Scattering experiment in Germany, developed a modular Particle Flow algorithm for a future lepton linear collider, and adapted analysis techniques developed for hadron colliders for use in reconstruction of neutrino scattering events. He is currently a member of the NOvA Neutrino Oscillation Experiment, the Muon to Electron direct conversion (Mu2e) Experiment, and the DUNE Neutrino Oscillation Experiment with current participation in the ProtoDUNE Single Phase detector prototype at CERN. Publications include papers on the ZEUS Experiment, Linear Collider R&D, the NOvA Long-Baseline Neutrino Experiment, and on unique techniques using nanoparticles to detect UV light from crystals and noble liquids and gases.
Lisa Goodenough is a postdoctoral researcher in the High Energy Physics Division (HEP). Her broad research interests include utilizing computing technologies such as high performance computing and machine learning in HEP, precision experimental muon physics, and dark matter (DM) detection and phenomenology. Goodenough is a member of the Mu2e Experiment, an experiment designed to look for muon-to-electron direct conversion with an increase in sensitivity over its predecessor of five orders of magnitude. For Mu2e she is currently developing Monte Carlo event simulation software to run on supercomputers such as Mira and Theta at the Argonne Leadership Computing Facility. Her work on dark matter includes investigating the discoverability and viability of models of dark matter taking into account data from indirect detection experiments. With her collaborators, Goodenough was the first to analyze the Fermi Gamma-Ray Space Telescope data to observe the gamma-ray excess in the Galactic Center and to determine the excess to be consistent with dark matter annihilation in the Galactic Center. In addition, she was the first to explain the results from several cosmic ray and gamma ray experiments in terms of a single theory of dark matter.