[Triumf-seminars] TRIUMF Special Seminar today at 11:00

[TRIUMF Seminars]

Date/Time: Wed 2022-11-02 at 11:00

Location:  Auditorium          

Speaker:   Rene Reifarth and Iris Dillmann (Goethe University Frankfurt and TRIUMF)

Title:     Neutron captures of short-lived radioactive nuclei in storage rings

Abstract: Part of the CaNPAN i/n-process workshop, open to the whole lab: 
https://sites.google.com/view/canpan2022/home
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Rene and Iris will introduce the specifics of the two presently discussed projects (at LANL with a spallation neutron source and at TRIUMF with a high-flux neutron generator) for employing a heavy-ion storage ring and a neutron target to measure direct neutron capture cross sections of short-lived nuclei. The two talks are followed by a discussion (30+10min each) .

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Virtually all of the isotopes heavier than iron would not exist without neutron-induced reactions. The most important reactions in astrophysics are neutron capture and neutron-induced fission. Despite their importance in many different scenarios, there are almost no direct measurements in the astrophysically interesting energy regime for isotopes with half-lives shorter than a few years. Current experimental techniques, like time-of-flight or activation technique, require the production of a sample to be placed close to a detector during or after the irradiation with neutrons. This limits the activity of the sample resulting in a lower limit for the half life. 

A radically new approach is necessary to overcome this constraint. An idea is to invert the kinematics of the experiment. Radioactive ions will be accelerated and sent through a target of free neutrons. The neutrons need to be constantly produced and trapped in order to act as a "gas" target. Highest neutron densities require either a nuclear reactor or a spallation neutron source. 

Spallation sources can reach even higher neutron densities than nuclear reactors and have the additional advantage of intrinsically higher safety. Such a source in combination with an ion storage ring and an ISOL facility can bring the half-life limit for feasible measurements down to fractions of a minute. This new approach requires a community effort, since no facility like it exists anywhere in the world. Challenges concerning the spallation source, the ion storage ring and detection mechanisms have to be addressed. We will review the status of current experiments as well as the status and prospects of this new endeavor.
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https://uvic.zoom.us/j/85287095773?pwd=b2N5SWtJaDQ3VW5GbzlWdmNDamsydz09

Meeting ID: 852 8709 5773
Password: 76876432

Hybrid meeting

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