Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle
Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle
Theses and Dissertations
We create a dual-species ultracold neutral plasma (UNP) by photo-ionizing Yb and Ca atoms in a dual-species magneto-optical trap. Unlike single-species UNP expansion, these plasmas are well outside of the collisionless (Vlasov) approximation. We observe the mutual interaction of the Yb and Ca ions by measuring the velocity distribution for each ion species separately. We model the expansion using a fluid code including ion-ion friction and compare with experimental results to obtain a value of the Coulomb logarithm of Λ= 0.04.
Simulating The Fticr-Ms Signal Of A Decaying Beryllium-7 Ion Plasma In A 2d Electrostatic Pic Code, Michael Takeshi Nakata
Simulating The Fticr-Ms Signal Of A Decaying Beryllium-7 Ion Plasma In A 2d Electrostatic Pic Code, Michael Takeshi Nakata
Theses and Dissertations
Beryllium-7 (Be-7) only decays by electron capture into lithium-7 (Li-7) with a half life of 53 days. We study the effect of ionization on this decay rate. We do so by trapping a Be-7 ion plasma in a cylindrical Malmberg-Penning trap and measuring Be-7 and Li-7 concentrations as functions of time by using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). We have simulated these signals in a 2-dimensional electrostatic particle-in-cell (PIC) code. The two spectrum peaks merge at high ion densities whereas at low ion densities they can be resolved. The merged peak shifts linearly according to the relative …