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PRODID:UW-Madison-Physics-Events
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UID:UW-Physics-Event-9492
DTSTART:20251124T190000Z
DTEND:20251124T210000Z
DTSTAMP:20260413T084208Z
LAST-MODIFIED:20251111T184024Z
LOCATION:B343 Sterling
SUMMARY:First ionization potentials of Cr\, Mo\, and W calculated with
  SHCI\, Thesis Defense\, Zachary Jerzyk\, Physics Graduate Student
DESCRIPTION:The design and performance of future fusion power plants w
 ill depend on accurate atomic data for plasma-facing material and plas
 ma impurity species. A leading candidate for the plasma-facing materia
 l is tungsten due to its high melting point\, however\, the energy lev
 els and wavefunctions of high-Z atoms with many electrons (e.g. 30 or 
 more)\, including tungsten\, are difficult to calculate with high accu
 racy. Gaps and large uncertainties in atomic data for tungsten introdu
 ce design and performance uncertainties for a fusion power plant. Spec
 ifically\, improved atomic data for ionization potential\, excited sta
 te energies\, and collisional excitation rates are needed for the low 
 charge states of atomic tungsten. We aim to address these shortcomings
  by using the semistochastic heat-bath configuration interaction (SHCI
 ) method\, which nearly exactly calculates the energies that can be de
 termined at higher cost with the full configuration interaction. Addin
 g well-motivated approximations to SHCI\, including orbital optimizati
 on and effective core potentials\, we demonstrate good agreement betwe
 en our calculated first ionization potentials and the best available e
 xperimental values for chromium\, molybdenum\, and tungsten. The effic
 iency and accuracy achieved in calculating these ionization potentials
  demonstrates that our SHCI workflow can yield improved electron struc
 ture data for ions with many electrons\, suggesting that the method co
 uld also be useful for collisional processes\, such as state-selective
  charge exchange reactions and electron impact ionization.
URL:https://www.physics.wisc.edu/events/?id=9492
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