Events at Physics |
Events During the Week of January 27th through February 3rd, 2019
Monday, January 28th, 2019
- Plasma Physics (Physics/ECE/NE 922) Seminar
- The new Divertor Tokamak Test facility project
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Piero Martin, University of Padova and Consorzio RFX, Padova, Italy
- Abstract: The Divertor Tokamak Test Facility (DTT) is a new tokamak whose construction has recently been approved by the Italian government. DTT will be a high field superconducting toroidal device (6 T) carrying plasma current up to 5.5 MA in pulses with length up to 100s and with 45 MW of additional heating power, with an up-down symmetrical D-shape defined by major radius R=2.11 m, minor radius a=0.64m. DTT key mission is contributing to the development of a reliable solution for the power and particle exhaust in a magnetic confinement fusion reactor, a challenge commonly recognised as one of the major issues in the roadmap towards a fusion power plant. In addition to its main goal, DTT will be a flexible high-performance device – equipped with advanced control tools - aiming at the investigation of fully integrated core-edge scenarios, both in standard and advanced tokamak configurations. This talk will briefly discuss the path which lead to the DTT approval, give an overview of the DTT interim design and illustrate the present main physics and technical choices, the overall status of the project and the plan for the short and medium-term future. *on behalf of the DTT executive board (Raffaele Albanese, Flavio Crisanti, Piero Martin, Aldo Pizzuto) and of the DTT team
Tuesday, January 29th, 2019
- Chaos & Complex Systems Seminar
- Screening for “normal” genetic variants: Using survey data to inform precision medicine
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Marsha Mailick, Waisman Center
- Abstract: This talk will begin with the gene that causes a rare genetic disease, and consider how variants in this gene affect all of us. The rare genetic disease is Fragile X Syndrome, which affects 1 in 5000 births and is caused by a mutation in the FMR1 gene on the X chromosome. This gene is critically important for brain development and functioning throughout the lifespan. Although it is rare, Fragile X Syndrome is the most common inherited cause of intellectual disability and also the most common genetic cause of autism. Besides the “full mutation” that causes Fragile X Syndrome, variants in the FMR1 gene have been implicated in other health conditions. These gene variants are familial, passed from one generation to the next, and thus there are family-wide implications for reproductive decision making and parenting. However, until recently, the data were all derived from clinical patient groups, and thus, there is considerable ascertainment bias and uncertainty in generalizing to the full population. For the past decade, we have been studying the full range of FMR1 gene variations in both clinical patient groups and through population survey data. By cross-referencing data from both sources, we have been able to advance understanding of the impacts of what previously were believed to be normal variants of FMR1, but which actually have consequences for human health. In this era of precision or personalized medicine, understanding the implications of such variants can inform the health care we receive, but only if such variants are screened for and understood.
- Host: Clint Sprott
- Council Meeting
- Time: 3:30 pm - 4:30 pm
- Place: 2314 Chamberlin Hall
- Speaker: Sridhara Dasu, UW-Madison
- Host: Sridhara Dasu
Wednesday, January 30th, 2019
- No events scheduled
Thursday, January 31st, 2019
- Atomic Physics Seminar
- Continuous loading of ultracold ground state molecules in a dipole trap using a single light beam
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Professor Luis Marcassa, Universidade de Sao Paulo, Brazil
- Abstract: We have developed an approach to continuously load ultracold 85Rb2 vibrational ground state molecules into a crossed optical dipole trap from a magneto-optical trap. The technique relies on a single high-power light beam with a broad spectrum superimposed onto a narrow peak at an energy of about 9400 cm-1. This single laser source performs all the required steps, namely the photoassociation, vibrational cooling, and optical trapping of the molecules. We have also performed depletion spectroscopy, which allows us to determine that 75% of the vX= 0 molecules are in J= 0, 1 and 2 rotational states. The lifetime of the ultracold molecules in the optical dipole trap is limited by off-resonant light scattering to about 70 ms. The proposed technique may open perspectives for the formation of new molecular species in the ultracold domain, which are not yet accessible by well-established approaches.
- Host: Saffman
- Cosmology Journal Club
- Time: 12:00 pm - 1:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details:
http://cmb.physics.wisc.edu/journal/index.html
Feel free to bring your lunch!
If you have questions or comments about this journal club, would like to propose a topic or volunteer to introduce a paper, please email Ross Cawthon (cawthon@wisc.edu) and Santanu Das (sdas33@wisc.edu). Friday, February 1st, 2019
- R. G. Herb Condensed Matter Seminar
- Competing orders in non-centrosymmetric superconductors
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Maxim Khodas
- Abstract: As a motivation I review several recent experiments on transition metal dichalcogenides. Then I will present what is known about these materials and what makes there response to the magnetic field special. I will then review the spin-orbit coupling based on symmetry considerations. Then I'll focus on the singlet to triplet conversion induced by the Zeeman field. Finally I'd discuss the effect this has on the critical field.
- Host: Levchenko
- Department Meeting
- Time: 11:30 am - 12:30 pm
- Place: B343 STERLING HALL
- Speaker: Sridhara Dasu, UW-Madison
- Host: Sridhara Dasu
- Astronomy Colloquium
- UPDATED TIME AND DATE
- Infrared Spectroscopy of Stars and Planets
- Time: 2:30 pm - 4:00 pm
- Place: 4421 Sterling Hall, Coffee and cookies 2:30 PM, Talk begins 2:45 PM
- Speaker: Ian Crossfield, MIT Dept of Physics
- Abstract: Extrasolar planets and cool stars emit most of their light beyond the range of standard optical observations. These objects are often best studied using infrared spectroscopy. I will present recent results from my group on two topics: space-based IR spectroscopy of exoplanet atmospheres, and ground-based, high-resolution spectroscopy of both planets and stars. I will also conclude with a brief discussing of how future IR-optimized observatories will also enable exciting new science in these areas.
- Host: Amy Barger
- Physics Department Colloquium
- Making Movies of Molecules - The Application of X-ray Lasers
- Time: 3:30 pm
- Place: 2241 chamberlin Hall
- Speaker: Junko Yano, LBNL
- Abstract: Our group is studying the mechanisms of the catalytic reactions in both natural and inorganic systems. Using various X-ray techniques as tools, we are studying how the catalysts do multielectron reactions, by following the reaction under functional conditions.
We have developed spectroscopy and diffraction techniques necessary to fully utilize the capability of the X-ray Free Electron Laser facilities (XFELs) for a wide variety of metalloenzymes, and to study their chemistry under functional conditions. One of such methods is simultaneous data collection for X-ray crystallography and X-ray spectroscopy, to look at the overall structural changes of proteins and the chemical changes at metal catalytic sites. In parallel to the detection techniques, we have developed an efficient sample delivery method that involves deposition of droplets on a conveyor belt. This 'Droplet on Tape' (DOT) method, delivers a single drop of the crystal suspension or solution sample onto a tape, which then can be transported to the X ray intersection point with a variable delay in time. In the process, the sample is photochemically or chemically activated at various time delays to capture reaction intermediates with crystallography and spectroscopy.
The presentation will cover our group's recent results of metalloenzyme research, in particular, for the study of the water oxidation reaction in natural photosynthesis, using X-ray crystallography and X-ray spectroscopy at LCLS (LINAC Coherent Light Source).
References:
Kern, J. et al. Simultaneous femtosecond X-ray spectroscopy and diffraction of Fuller, F. D. et al. Drop-on-demand sample delivery for studying biocatalysts in action at XFELs Nat. Methods 14, 443 (2017).
Kubin, M. et al. Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers, Struct. Dynamics 4, 054307 (2017)
Kern, J. et al. Structures of the intermediates of Kok’s photosynthetic water oxidation clock. Nature 563, 421 (2018). - Host: Pupa Gilbert