Summary


1	Date	2/23/2018
2	Name	Ivan Sadovskyy
3	Affiliation	Computation Institute, University of Chicago, 5735 S. Ellis Av., Chicago, IL 60637, USA Materials Science Division, Argonne National Laboratory, 9700 S. Cass Av., Argonne, IL 60637, USA
4	Home Page
5	Colloquium Title	Targeted Evolution for Designing better Superconductors
6	Abstract	Understanding the dynamic behavior of vortex matter in complicated pinning landscapes is a major challenge for both fundamental science and energy applications. The critical current - the largest current a superconductor can carry - is mostly defined by non-superconducting inclusions within the superconductor, which prevents (pins) magnetic vortices from moving. The landscape of these inclusion yielding the largest critical current is very difficult to predict Using large-scale time-dependent Ginzburg-Landau simulations for vortex dynamics [1] combined with he critical-current-by-design concept [2] we are able to predict the optimal defect landscape for targeted applications by elucidating the vortex dynamics responsible for the critical current [3]. [1] I. S. et al., Phys. Rev. Applied 5, 014011 (2016). [2] I. S. et al., Adv. Mat. 28, 4593 (2016). [3] A. E. Koshelev, et al., Phys. Rev. B 93, 060508 (2016).
7	Host	Andreas Glatz
8
9	Date	3/2/2018
10	Name	Ben Freemire
11	Affiliation	Northern Illinois University Department of Physics
12	Home Page
13	Colloquium Title	Space Charge Compensation Using an Electron Column at Fermilab’s Integrable Optics Test Accelerator
14	Abstract	Current particle accelerators are limited in the beam intensity that can be achieved because of the electromagnetic self-fields of the beam particles. These effects, collectively referred to as “space charge effects”, produce a defocusing force on the beam, which leads to instabilities and loss. For hadron accelerators, the space charge effect can be counteracted by matching the charge distribution of the beam to that of an electron cloud. This is accomplished by maintaining a short section of the beamline at a higher background gas density, allowing the beam to generate a plasma by ionizing the gas. Using external electric and magnetic fields, the electron distribution can be matched to that of the beam, while the ions are free to exit the column. An experimental program to demonstrate space charge compensation using an electron column is planned for the Integrable Optics Test Accelerator (IOTA) at Fermilab. The status of the electron column program and IOTA will be discussed.
15	Host	Carol Thompson
16
17	Date	3/23/2018
18	Name	Umeshkumar Patel
19	Affiliation	X-ray Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439.
20	Home Page
21	Colloquium Title	Superconducting Circuits for Quantum Information and X-ray Detection Technology
22	Abstract	Superconducting quantum circuits are very promising candidates for scalable quantum information processing. The fundamental element of these circuits is the Josephson junction which provides large nonlinearity, and negligible dissipation essential for useful qubit states. Over the last decade, the coherence time of individual qubits improved by many orders of magnitude, and multi-qubit experiments have been demonstrated. I will give an overview of this exciting and rapidly developing field and discuss experiments on improvements in coherence of superconducting qubits [1] and quasiparticle poisoning in quantum circuits [2]. In addition, I will report our recent work on energy-dispersive X-ray detectors using superconducting circuits [3]. [1] U. Patel et al, Appl. Phys. Lett. 102, 012602, 2013. [2] U. Patel et al, Phys. Rev. B 96, 220501(R), 2017. [3] D. Yan, et al, Appl. Phys. Lett. 111, 192602, 2017.
23	Host	Zhili Xiao
24
25	Date	4/6/2018
26	Name	Alexey Snezhko
27	Affiliation	Materials Science Division, Argonne National Laboratory, 9700 S. Cass Av., Argonne, IL 60637, USA
28	Home Page	http://www.anl.gov/msd/person/alexey-snezhko
29	Colloquium Title	Active Spinner Materials
30	Abstract	Strongly interacting colloids driven out-of-equilibrium by an external periodic forcing often develop nontrivial collective dynamics. Active magnetic colloids are excellent model systems to explore emergent behavior and out-of-equilibrium phenomena. I will discuss ferromagnetic micro-particles, suspended at a liquid interface and energized by a uniaxial in-plane alternating magnetic field spontaneously forming arrays of self-assembled spinners rotating in either direction. Experiments reveal nontrivial dynamics in large ensembles of synchronized magnetic spinners. Further, magnetic micro-particles immersed in water and sediment on the bottom surface, which turn into colloidal rollers when energized by a single-axis homogeneous alternating magnetic field. We observe rich collective dynamics of magnetic rollers, including flocking and spontaneous formation of steady vortex motion. References: G. Kokot et al., PNAS 114,12870 (2017) A. Kaiser et al., Science Adv. 3, e1601469 (2017)
31	Host	Andreas Glatz
32
33	Date	4/13/2018
34	Name	Tammy Walton
35	Affiliation	Fermilab
36	Home Page
37	Colloquium Title	Measuring the Beam Dynamics for the Muon g-2 Experiment at Fermilab
38	Abstract	There exists a factor greater than 3 sigmas discrepancy between the experimental measurement and Standard Model prediction of the anomalous magnetic moment for the muon. The Muon g – 2 experiment at Fermilab will reduce the experimental uncertainty of 540 to 140 parts per billion. This includes improving the systematic uncertainty by a factor of 3. A significant reduction in the systematic uncertainty for sources associated with the dynamics of the muon beam are needed in order to achieve the expected goal. The Muon g - 2 experiment is equipped with in-situ, advanced tracking detectors, which are indirectly measuring the beam dynamics. This presentation focus on using those detectors to understanding the dynamics of the muon beam.
39	Host	Michael Eads
40
41	Date	4/20/2018
42	Name	Michael Eads
43	Affiliation	Northern Illinois University Department of Physics
44	Home Page
45	Colloquium Title	Using Concept Inventories to Enable General Physics Course Reform at NIU
46	Abstract	Northern Illinois University is a large, public, research university located 40 miles west of Chicago. About 500 students enroll in algebra- and calculus-based general physics courses each semester. The format of these courses has historically been very traditional, focused on lectures with a weekly lab session. Starting in 2013, standard assessment instruments (such as the Force Concept Inventory) were administered as part of an effort to critically assess the effectiveness of these courses. As of the Fall 2015 semester, concept inventories were administered in all sections and levels. This data is now being used to help judge the effectiveness of several course improvement efforts, including a small Themed Learning Community section that has implemented a variety of active learning strategies. Success with the Themed Learning Community section has now led to further course improvement efforts.
47	Host	Michael Eads
48
49	Date	4/27/2018
50	Name	Physics Department Presents
51	Affiliation	Northern Illinois University
52	Home Page
53	Colloquium Title	Senior Seminar and Awards ceremony
54	Abstract	NIU Physics Department Senior Seminar and Awards ceremony Phys 498 and Phys 499 student
55	Host	Carol Thompson