BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:2 UID:UW-Physics-Event-8008 DTSTART:20221209T190000Z DTEND:20221209T180000Z DTSTAMP:20260414T113553Z LAST-MODIFIED:20221209T185025Z LOCATION:B343 Sterling or https://uwmadison.zoom.us/j/98705802404?pwd= L1hmMFRMRFA2aW0wdFQrU0o0TGFFdz09 SUMMARY:New Frontiers in Collisionless Reconnection: Exploring Magneto sphere-Relevant Reconnection with Experiments and Custom Kinetic Simul ations\, Thesis Defense\, Samuel Greess\, Physics Graduate Student DESCRIPTION:Magnetic reconnection is a ubiquitous phenomenon throughou t the universe\, but in terms of proximity\, its occurrence at the day -side magnetopause is the instance that is closest to Earth both spati ally and in importance to human life. At the day-side magnetopause\, t he solar magnetic field reconnects with the magnetic field of the Eart h\, beginning the process that results in the transfer of energized so lar wind particles into the Earth's upper atmosphere. Usually\, the re sult of these incursions is only the ethereal beauty of the auroras (b orealis and australis)\; however\, larger quantities of incident plasm a can and have had devastating effects on terrestrial and space-based electronic systems. Predicting these geomagnetic storm events depends on an understanding of both how and when large quantities of plasma ar e emitted from the Sun (also a reconnection-based event) and how long it will take for these particles to enter the Earth's atmosphere via t he magnetopause reconnection process. To that end\, in addition to sat ellite missions created to measure the in situ process\, experiments a nd simulations here on Earth are studying reconnection in the relevant parameter regimes\, particularly in plasmas whose collisionality is l ow enough to mimic the space environment. One such experiment is the T errestrial Reconnection EXperiment (TREX)\, which is based as the Univ ersity of Wisconsin-Madison as a partner of the Wisconsin Plasma Physi cs Laboratory (WiPPL) collaborative research facility. TREX is designe d to access the kinetic regime\, which is typified by thin current lay ers\, anisotropic pressure distributions\, and fast reconnection. In c onjunction with TREX\, the newly developed Cylindrical VPIC (Vectorize d Particle-in-Cell) code from Los Alamos National Laboratory has been used to simulate TREX in manner that preserves the experiment's cylind rical symmetry while optimizing computational efficiency. Different mo dified versions of the basic TREX VPIC setup have been successfully us ed to confirm and complement experimental findings\, as well as to inv estigate plasma regimes the experiment cannot (presently) reach and to model different proposed TREX drive coil geometries. This thesis will present work from both the TREX laboratory and TREX VPIC simulations\ , with an emphasis on comparing the measured properties of reconnectio n in both scenarios and demonstrating how these data align with theore tical predictions about the kinetic reconnection parameter regime. Sig nificant background to the construction and operation of TREX\, Cylind rical VPIC\, and relevant portions of the WiPPL facility will also be included. URL:https://www.physics.wisc.edu/events/?id=8008 END:VEVENT END:VCALENDAR