[Triumf-seminars] TRIUMF Colloquium today at 14:00

[TRIUMF Seminars]

Date/Time: Wed 2016-03-16 at 14:00

Location:  Auditorium          

Speaker:   Daniel Lascar (TRIUMF)

Title:     Astrophysical Mass Measurement at TRIUMF

Abstract: A majority of stable species on the chart of nuclides are decay products of short-lived, neutron-deficient or neutron-rich parent nuclei generated in explosive astrophysical events (rp-process, nup-process and r-process). Nuclear masses are perhaps the most important experimental quantity for determining reaction paths in these processes. Because they occur so far from stability, very little is known about the progenitor nuclei in these explosive reaction paths due to the extreme difficulty in rare isotope production of these exotic species. As a result mass models are relied upon heavily to help understand heavy nucleosynthesis where mass predictions can vary by several tens of MeV/c2. Mass measurements of nuclei far from stability are therefore critical to constrain new and existing mass models then minimizing the need for those models as measured data replace model values.

Unfortunately with the current operation of rare isotope beam facilities these nuclei are difficult, if not impossible, to produce. The TITAN facility at TRIUMF is at the leading edge of precision mass measurements of short-lived nuclei using Penning trap mass spectrometry, and is in place to take advantage of the clean, exotic, neutron-rich beams provided by ARIEL. We are in the process of commissioning a new Cooler PEnning Trap (CPET) which will cool charge-bred ions with a simultaneously trapped plasma of electrons to further improve the precision of their measured masses. During commissioning, we have made use of a novel, charge agnostic, in-magnet detector that can be made effectively transparent to charged particles passing through it. Dubbed the "mesh detector," it has allowed CPET to move forward with the next phase of development: the simultaneous trapping and eventual cooling of highly-charged ions with a self-cooling plasma of electrons.

Looking forward, as ARIEL comes online to provide TITAN access to cleaner beams of more exotic neutron-rich nuclei, another device at TRIUMF, the ElectroMagnetic Mass Analyzer (EMMA), is well-positioned to study neutron-deficient nuclei produced in the higher energy nuclear reactions in ISAC-II. A new Penning trap system, EMMAtrap, coupled to the focal plane of EMMA is in the early planning phases and will be designed to take advantage of focused, mass-separated, neutron-deficient nuclei from EMMA to study constrain the rp-process.

The seminar will be streamed and recorded, please contact Niki Martin for details.



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General TRIUMF seminar information available at http://www.triumf.ca/home/upcoming-events/about-seminars-lectures