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Upcoming Seminars & Lectures

DateTime SpeakerLocationTitle
10:00ColloquiumSarah Dunsiger
Simon Fraser U
AuditoriumDepth Resolved Spin Resonance Techniques for Spin Transport Applications
Abstract:The fields of spintronics aims to combine the data storage capabilities of magnetic media with the data handling capabilities of the semiconductor industry. As such, the controlled manipulation of a nonequilbrium spin population is required. For example, spin pumping relies on the precession of the magnetisation induced in a ferromagnet excited by a radio-frequency magnetic field on resonance (FMR). The magnetisation precession around an effective magnetic field is damped via the emission of a polarised spin current into the neighbouring normal metal. The flow of this spin current Js across a ferromagnet/normal metal interface may then be detected. Indirect evidence of spin pumping from bulk transport measurements of the charge current Jc induced through the Inverse Spin Hall Effect (ISHE) has been reported in a variety of artificial heterostructures. Our ultimate goal is to look for direct evidence of spin pumping into the nonmagnetic layer of the heterostructures using a depth resolved local probe, measuring the spin diffusion length and spin decoherence timescales. I will discuss recent investigations using the depth resolved spin resonance techniques Low Energy muSR and beta-detected Nuclear Magnetic Resonance (beta-NMR) of the internal magnetic fields and spin lattice relaxation in simple nonmagnetic metals and semiconductors adjacent to archetypal magnets, artificial heterostructures of great interest in curiosity driven research but also of relevance for spin transport applications.
11:00AcceleratorHolger Podlech
Goethe University, Frankfurt
AuditoriumNew Developments for RFQ Accelerators and CH-Cavities
Abstract:RFQ accelerators are the standard devices for bunching, focusing and acceleration of hadron beams at low energies. While for protons mostly 4-Vane RFQs at higher frequencies are used, the 4-Rod Structure is the common structure for heavier ions. During the last years a program has been initiated to overcome some of the disadvantages of 4-Rod RFQs as an intrinsic dipole component and limiting cooling capabilities for high power operation. CH-cavities belong to the family of H-mode cavities using the H211-mode. In general, they have high shunt impedance and can be operated at higher frequencies compared to IH-cavities. Due to the mechanical rigidity CH-cavities can be realized for room temperature and superconducting operation. During the last years several CH-cavities have been developed and tested with high gradients up to 14 MV/m. In 2017 the first beam test of a superconducting CH-cavity has been performed successfully.
Wed ,
14:00ColloquiumKarl Johnston AuditoriumApplying radioactive isotopes to solid state and medical physics: staying relevant in a fast-paced world
Abstract:Having an isotope factory close-by can be a real opportunity to perform innovative experiments in solid state and medical physics. Among the many advantages of radioactivity in solid state physics are its sensitivity and ability to probe local environments in a transparent manner. The ability to pick and choose relevant isotopes for varying chemical systems also opens up many possibilities for unique work in medical physics. However, the pace of nuclear physics and developments in solid state physics are not well-matched: the latter has a considerably faster turnover with "hot" materials changing quickly within a short time frame - especially with regard to the building of nuclear physics infrastructure. I will present recent results, developments and challenges faced at ISOLDE for the applications programme in recent years. Results on applying hyperfine techniques to materials such as topological insulators will be presented as will some of the novel isotopes currently being applied to medical physics. The talk will conclude with perspectives on future possibilities at TRIUMF with muon spin resonance, beta-NMR and beyond.
Fri ,
14:00SpecialPSD Mixer
AuditoriumPSD Mixer
Abstract:Jens Dilling - Division updates (10 minutes) Q&A with Jens (15 minutes) Talk by Rob Kiefl (20 minutes) Discussion period w/pizza (30 minutes) -- Rob Kiefl (UBC) "Developments in muSR and beta-NMR and the 2017 Yamazaki Prize" In this talk I will review some highlights of our efforts to explore and understand the behaviour of muons and radioactive nuclei in condensed matter, as well as the unique information these probes provide. Many of the scientific advances in the use of muSR and beta-NMR are closely connected to technical developments made here at TRIUMF. In the first part of my career we developed a powerful new method to study behaviour of muonium (mu+e-) in semiconductors and learned many surprising things about muonium - its electronic structure and relationship to hydrogen. Hydrogen is present in all semiconductors and can alter its properties. Most of the information we have on isolated hydrogens comes indirectly through studies of the muonium. The second part of my career began with the discovery of high temperature superconductors in the late 1980's. Suddenly the larger condensed matter physics community realized the importance of muSR in studies of superconductivity and magnetic parent compounds from which they came. New high field methods were first developed here which allowed us to obtain detailed information on the link between magnetism and superconductivity in high Tc superconductors. For the last part of my career I have worked on developing beta-detected NMR as probe of thin films and interfaces using the unique low energy polarized beams of radioactive nuclei at ISAC. Beta-NMR is almost identical to μSR in principle but the longer lifetime of 8Li allows one to probe the system on a very different time scale. Also, the low energy of ISAC radioactive beams means that beta-NMR is ideally suited to studies of thin films and interfaces.
Wed ,
16:00SpecialKuo-Shyan Lin
BC Cancer Agency, Department of Molecular Oncology
AuditoriumIsoSiM Seminar: Cyclotron Production of Technetium-99m at the BC Cancer Agency
Fri ,
14:00ColloquiumLiliana Caballero
University of Guelph
AuditoriumMulti-messenger signals from neutron-star mergers
Abstract:The recent observation of the first neutron-star binary merger (GW170817), in August last year, has solidified several ideas that theoretical models have proposed for the last decade regarding the possible outcomes of such events. However, there are many open questions that require further exploration. In this colloquium, I shall present the multi-messenger signals from this first coalescence and discuss the role of some aspects of nuclear physics in their interpretation.
Thu ,
14:00ColloquiumEkaterina Dadachova
U Saskatchewan
AuditoriumRadioimmunotherapy with alpha-particles emitting radionuclides of cancer and infections
Abstract:The use of targeted therapy with alpha particles emitters in oncology is burgeoning worldwide. This is driven by the advantages of alpha emitters over beta emitters, including very specific targeting of the diseased cells due to the alpha particles' short 50-80 micron tissue range, and increased killing efficiency due to high linear energy transfer. This results in a controlled therapeutic modality with minimal normal tissue effects. Radioimmunotherapy (RIT) with alpha emitters does not depend on the oxygenation status of the tumor, and alpha therapy can break tumor resistance to chemotherapy, external beam radiation therapy, and even to beta radiation therapy. In our laboratory we are investigating novel antigens and antibodies for using alpha RIT to treat melanoma and pancreatic cancer. Several years ago we were the first to translate alpha RIT approach into the field of infectious diseases for treatment of opportunistic fungal infections, multidrug resistant bacterial infections and HIV. The latest results of our pre-clinical work will be described.
Thu ,
ColloquiumSunil Krishnan
MD Anderson Cancer Center
Thu ,
14:00ColloquiumCharles Horowitz
University of Indiana
AuditoriumThe neutron star merger GW170817 and neutron rich matter in the laboratory and in the heavens
Abstract:Compress almost anything to very high densities and electrons react with protons to make neutron rich matter. This material is at the heart of many fundamental questions in nuclear physics and astrophysics. What are the high-density phases of QCD? Where did the chemical elements come from? What is the structure of many compact and energetic objects in the heavens, and what determines their electromagnetic, neutrino, and gravitational-wave radiations? Recently, extensive gravitational wave and electromagnetic observations of the neutron star merger GW170817 have constrained the equation of state of neutron rich matter and strongly suggest that neutron star mergers are an important site of rapid neutron capture (r-process) nucleosynthesis of heavy elements such as gold and uranium. We discuss these historic developments and try and place them in a broad context. We describe how the thickness of the neutron skins of the 48Ca and 208Pb nuclei are being measured with parity violating electron scattering at Jefferson Laboratory. These skins depend on the pressure of neutron rich matter and have important implications for the structure of neutron stars. We expect many thousand neutrino events from the next galactic core collapse supernova (SN). Simple neutrino interactions suggest that the neutrino driven wind is not very neutron rich and thus, despite what is said in many textbooks, SN may not be the site of the r-process for heavy elements. Finally, GW170817, by suggesting the astrophysical conditions, has set the stage for TRIUMF ISAC / ARIEL and other radioactive beam facilities to perform detailed studies of r-process nucleosynthesis.
Thu ,
14:00ColloquiumBrad Filippone
Thu ,
14:00ColloquiumRoger Melko
U Waterloo
Thu ,
14:00ColloquiumJoseph Bramante
CPARC/Queen's U
AuditoriumUsing Neutron Star Mergers to Search for Asymmetric Dark Matter
Abstract:I will show how heavy asymmetric dark matter could be found using the locations of neutron star mergers in galaxies, and by observing a new type of astrophysical event, a "quiet kilonova," in which a neutron star implodes into a black hole made of dark matter accumulated at its center.