Monday, April 1, 2019, 1:30 PM, room 112 Jennifer Shursterman (CUNY)
The neutron capture cross section of 88Zr- A surprise in the chart of the nuclides
The chemistry of Zr is important to various areas of nuclear science including nuclear medicine, fuel cycle, forensics, and stockpile stewardship. Despite this, the nuclear reaction networks surrounding radioactive isotopes of Zr have notable gaps in cross-section data. A reaction network of interest for stockpile stewardship surrounds 88Zr, which prior to this work was void of experimental measurements of the neutron-capture cross section. To perform the first measurement of its neutron-capture cross section, 88Zr was produced via the 89Y(p,2n) reaction at the University of Alabama at Birmingham Cyclotron Facility. The 88Zr was radiochemically purified from the Y and made into several targets for neutron irradiations. Irradiations of the 88Zr targets were performed at the University of Missouri Research Reactor using primarily thermal neutrons. Post-irradiation gamma-ray spectroscopy was used to quantify the 88Zr and 89Zr and from that calculate the neutron-capture cross section. We measured the neutron-capture cross section to be 100,000 times larger than the predicted value, demonstrating the importance of experimentally determining these quantities. With increased access to hard-to-produce radionuclides and advancing neutron-irradiation capabilities, more surprising neutron-capture cross sections may reveal themselves, furthering the understanding of the nuclear physics surrounding these occurrences.