Events During the Week of March 31st through April 7th, 2024
Sunday, March 31st, 2024
- Academic Calendar
- Spring recess
- Abstract: *Note: actual end time may vary.*
Monday, April 1st, 2024
- Academic Calendar
- Spring Semester Classes resume
- Abstract: *Note: actual end time may vary.* URL:
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Opening the PeV Neutrino Window with Trinity
- Time: 9:00 am - 10:00 am
- Place: 5310 Chamberlin Hall and
- Speaker: A. Nepomuk Otte, Georgia Tech
- Abstract: The stunning discoveries of the IceCube Neutrino Observatory have had a transformational effect on high-energy astrophysics. In this talk, I discuss the Trinity Demonstrator, the first step toward a Trinity Neutrino Observatory, which follows in the footsteps of IceCube by offering the prospect of detecting neutrinos at even higher energies (>petaelectronvolts). The goal is to unlock some of Nature’s best-kept secrets and explore fundamentally new physics.
- Host: Francis Halzen
- Plasma Physics (Physics/ECE/NE 922) Seminar
- “Disruption physics gaps encountered in the SPARC design pertinent to the design of the ARC power plant”
- Time: 12:00 pm - 1:15 pm
- Place: 1227 Engineering Hall
- Speaker: Ryan Sweeney, MIT PSFC/CFS
- Abstract: R. Sweeney on behalf of the SPARC and ARC Teams
Addressing climate change with a tokamak-based fusion power plant requires that plasma disruptions pose a low risk to day-to-day operation or to early end of life for in-vessel components. Advancing disruption resilience requires a tokamak that can create a reactor-scale environment for testing proposed solutions but can also survive disruptions if the solution fails, enabling a fast-learning cycle. Commonwealth Fusion Systems (CFS) is developing disruption resilient tokamaks equipped with robust plasma control software to meet this need. SPARC is a compact (R=1.85 m), high field (12.2 T) and current (8.7 MA) tokamak under construction in Devens, MA, designed to start operations in 2026. Its first mission is to demonstrate Q > 1 and will then be used to answer questions critical to the design of the ARC fusion power plant. SPARC is conservatively designed to structurally survive a battery of worst case disruption events and to tolerate melt events with tungsten based first wall components and no active cooling, and is equipped with state-of-the-art mitigation systems and diagnostics to retire the disruption risks for ARC. This talk will start with a brief overview of the status of the SPARC project with a focus on disruption systems. The remainder of the talk will address the disruption physics that set the most challenging requirements and drove actuator decisions for SPARC, highlighting where the larger community can complement the physics basis for the ARC power plant now under design. Disruptions are a known challenge, and the SPARC and ARC Teams welcome support as we sprint toward the solution in an effort to deploy fusion on the timescale that climate change requires.
Supplementary text on open disruption physics questions, with suggestions for studies: The predicted plasma current quench durations, based on ITPA scalings, drive the structural design of the SPARC vacuum vessel and in-vessel components. Improved physics understanding of these timescales would better inform the ARC design. A massive gas injection (MGI) system with six toroidally and poloidally distributed valves is the first mitigation technology that will be deployed on SPARC. Empirical and simulation comparisons of MGI with shattered pellet injection (SPI) and other alternatives would better inform the actuator decision for ARC. A novel runaway electron mitigation coil (REMC) is designed for SPARC and predictions suggest it will fully prevent runaway formation during disruptions at high current. Exploration of other runaway prevention solutions could provide optionality for the ARC design. Parallel heat fluxes from unmitigated and even some mitigated thermal quenches pose a risk to melting plasma facing tiles and other in-vessel components in SPARC. CFS and IPP Garching are exploring this physics on AUG; exploration on other machines would complement this planned dataset. The magnetic energy outside of the vacuum vessel can significantly increase the severity of disruption heat fluxes. Further understanding of this conversion would help to design ARC for these loads. While ARC will be designed to operate a single plasma scenario, SPARC is tasked with identifying the optimal ARC scenario and thereby must explore parameter space. Demonstrating physics-based disruption observers and avoidance could support SPARC operation, as well as physics studies of disruption causes including fusion-relevant material failure modes. - Host: Prof. Carl Sovinec
Tuesday, April 2nd, 2024
- Academic Calendar
- Election Day - Wisconsin Presidential Primary, including same-day registration
- Time: 7:00 am - 8:00 pm
- Abstract: Presidential Primary and County Board, School board, and Judges.. Presidential Primary and election for County Board, School Board, and Judges. Go to MyVote.wi.gov to find your assigned polling place, see what is on your ballot, and check your registration. If you are not registered at your current address, you can register at your polling place on Election Day. See vote.wisc.edu for information on registration and voter ID. CONTACT: malischke@yahoo.com URL:
- Academic Calendar
- Last Steps to Completing the Doctoral Degree
- Time: 12:00 pm - 1:00 pm
- Abstract: CONTACT: 262-2433, alexandra.walter@wisc.edu ONLINE:
- Wisconsin Quantum Institute
- Quantum Coffee Hour
- Time: 3:00 pm - 4:00 pm
- Place: Rm.5294, Chamberlin Hall
- Abstract: Please join us for the WQI Quantum Coffee today at 3PM in the Physics Faculty Lounge (Rm.5294 in Chamberlin Hall). This series, which takes place approximately every other Tuesday, aims to foster a casual and collaborative atmosphere where faculty, post-docs, students, and anyone with an interest in quantum information sciences can come together. There will be coffee and treats.
Wednesday, April 3rd, 2024
- No events scheduled
Thursday, April 4th, 2024
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Tuning into Cosmic Neutrinos at the Highest Energies
- Time: 9:00 am - 10:00 am
- Place: 5280 Chamberlin Hall
- Speaker: Stephanie Wissel, Penn State
- Abstract: Neutrinos are powerful probes of both astrophysics and fundamental particle physics at the highest energies. Weakly interacting and uncharged, they propagate undeterred and unabsorbed through the universe. In the last decade, we have observed a flux of high-energy (TeV-scale) neutrinos and through a multi-messenger lens — the combined observations of neutrinos and other messengers like photons — we are starting to see hints of energetic neutrino sources for the first time. At higher energies still, beyond the PeV scale, we can probe the most energetic sources of both neutrinos and cosmic rays, but current neutrino experiments become too small to observe a sizable flux. With long propagation lengths in both ice and air, radio detection offers an attractive solution to building the gigaton-scale detectors needed by allowing us to build sparse detectors sensitive to neutrinos over hundreds of kilometers. In this talk, I will review the landscape of current radio neutrino experiments and how next generation detectors can lead to new discoveries. I will also present my vision for the future of the Wisconsin IceCube Particle Astrophysics Center.
- Host: Francis Halzen
- R. G. Herb Condensed Matter Seminar
- Quantum materials through the nano-lens: surprises beyond the diffraction limit
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Alexander McLeod, UMN
- Abstract: Toolsets wielded by condensed matter researchers in the past century have expanded enormously into frontiers of the ultra-small and ultra-fast, today leveraging advancements like atomically precise crystal growth, nano-scale device assembly, and femtosecond spectroscopy with ultrafast photon pulses. On the other hand, despite breathtaking 20th century advancements in photon sources and detection technologies, our capacity to resolve condensed matter by optical spectroscopies has remained largely arrested by the diffraction limit since its 19th century observation by Ernst Abbe. However, recent decades have seen the marriage of “conventional” optics with scanning probes to circumvent the diffraction limit, realizing a nanometer-resolved optical spectroscopy mediated fundamentally by electromagnetic near-fields. In this seminar, I review and celebrate the breakthrough of this technique into the temperature and spatial scales relevant to fundamental studies of quantum materials. I showcase seminal investigations of collective excitations in 2-dimensional media like graphene, electronic phase competition in correlated electron solids including transition metal oxides, and on-demand control of optical properties in strongly interacting materials. I will share my perspectives for the future of nano-spectroscopy of quantum materials, a future that is simultaneously ultra-bright and ultra-small, and fundamentally transformative for the study of complex matter at nanometer scales.
- Host: Alex Levchenko
- Thesis Defense
- The Cosmic Symphony: Magnetic Fields and Turbulence Across Clouds, Galaxies, to Galaxy Clusters
- Time: 11:00 am
- Place: 5280 Chamberlin
- Speaker: Yue Hu, Physics Graduate Student
- Abstract: Turbulence and magnetic fields stand at the crossroads of astrophysical and cosmological inquiry, bridging microscopic physics, such as cosmic rays, to the large-scale galaxy cluster evolution. Despite their paramount importance, a thorough understanding of their characteristics has remained elusive. In this thesis, I explore the properties of magnetohydrodynamic (MHD) turbulence within a partially ionized medium through 3D MHD simulations of two-fluids (ions and neutrals), as well as the influence of stellar feedback. Furthermore, mapping the 3D magnetic field in spatial three dimensions has posed a century-long challenge. In this thesis, based on the anisotropic properties of MHD turbulence, I introduce three innovative techniques for tracing the 3D magnetic field: the Velocity Gradient Technique and the use of Convolutional Neural Networks. I will illustrate how these advancements in 3D magnetic field mapping significantly enhance our comprehension of star formation, Galactic magnetic fields, the CMB foreground polarization, Seyfert activities in nearby galaxies, and the evolution of galaxy clusters.
- Host: Alex Lazarian
- Department Meeting
- Time: 12:15 pm - 1:15 pm
- Place: B343 Sterling Hall
- Speaker: Mark Eriksson, UW - Madison
- Host: Mark Eriksson
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Multi-wavelength emission from Jets of nearby radio galaxies
- Time: 2:30 pm - 3:30 pm
- Place: CH 5280
- Speaker: Riku Kuze, Tohoku University
- Abstract: Relativistic jets in radio galaxies emit multi-wavelength photons, indicating the existence of nonthermal particles. However, the origin of these nonthermal particles is unknown. One plausible scenario is the electron-positron pair production via the two-photon interaction using the gamma rays produced by magnetic reconnection in the black-hole magnetosphere. This scenario is possible if the accretion flow is in a highly magnetized state, i.e., magnetically arrested disk (MAD) state. We construct the multi-wavelength photon emission model based on this scenario. In this talk, we will show the results of applying our model to M87. We calculate emissions from jets and MADs and compare the model prediction to the simultaneous multi-wavelength observational data for M87. We find that the emission from jets explains the optical to the X-ray data, and that from MADs explains the gamma-ray data. We also estimate the neutrino emission from jets and MADs, and we find that the neutrino luminosity is too low to observe by the IceCube Gen-2.
- Host: Ke Fang
- Astronomy Colloquium
- CANCELLED
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Abstract: CANCELLED
Friday, April 5th, 2024
- Physics Department Colloquium
- 2024 UW Physics Student Research Colloquium
- Time: 1:00 pm - 4:15 pm
- Place: 2241 Chamberlin Hall
- Speaker: UW Physics Students, University of Wisconsin-Madison
- Abstract: The event runs 1:00 PM – 4:15 PM: 1:00 PM – 2:00 PM, poster sessions (undergraduate research); 2:30 PM – 4:15 PM, graduate research presentations. For event and presentation details, visit the Research Colloquium webpage:
- Host: Elizabeth Hart-Baldridge
- Physics Department Colloquium
- Falling Walls Lab Wisconsin
- Time: 6:00 pm - 8:00 pm
- Place: 2241 Chamberlin
- Speaker: various, various
- Abstract: Which wall will your research break? Pitch your innovative idea in just three minutes, showcasing a breakthrough that positively impacts science and society. Free and open to the public.
- Host: Department of Physics, College of Letters & Science, and the Graduate School
Saturday, April 6th, 2024
- Outreach
- Physics Fair
- Time: 11:00 am - 2:00 pm
- Place: Chamberlin Hall, 2nd floor lobby
- Speaker: Various, Dept of Physics
- Abstract: The Physics Fair is an annual Department of Physics open house that typically includes laboratory tours, hands-on demonstrations, activities for kids and families, and informal conversations with scientists.
To sign up as a presenter, visit or email Sarah Perdue, saperdue@wisc.edu - Host: Sarah Perdue
- Wonders of Physics
- The Wonders of Physics show
- Time: 11:30 am - 12:15 pm
- Place: 2103 Chamberlin
- Abstract: The Wonders of Physics celebrates the 175th anniversary of UW-Madison. Free, no tickets needed!
