Using magneto-optical traps to measure ion-atom collision cross sections

David E. Fagnan, J. Wang, Bruce G. Klappauf +2 more

Chetan Vishwakarma, Kushal Patel, Jay Mangaonkar +1 more

A. Leredde, Patricia Barragán, A. Cassimi +4 more

A magneto-optical trap (MOT) has been coupled to a recoil-ion momentum spectrometer to study the charge exchange process in Na + + 87 Rb collisions in the keV impact energy range. The relative cross sections of the active charge exchange channels and the associated distributions in scattering angle were measured with a high precision. They provide a very detailed test of theoretical calculations.

Kristen Matherson, R. D. Glover, D. E. Laban +1 more

We present total absolute collision cross sections for neon in the $^{3}P_{2}$ metastable state with ground state, thermal atoms and molecules using a recently developed experimental technique. The technique utilizes a magneto-optical trap (MOT) and involves the measurement of MOT population dynamics to determine the cross section. Collision cross section measurements are presented for metastable neon in the $^{3}P_{2}$ state with He, Ne, Ar, ${\mathrm{H}}_{2}$, ${\mathrm{O}}_{2}$, and ${\mathrm{N}}_{2}$. The average thermal energy of the collision ranges from $11\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}27\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$. The measurements made using this technique have small errors, of the order of 10% of the measured cross section; the technique is capable of producing benchmark collision cross sections.

Douglas S. Goodman, James E. Wells, Frank A. Narducci +1 more

J. Blieck, X. Fléchard, A. Cassimi +3 more

A new magneto-optical trap-target recoil ion momentum spectroscopy apparatus has been built and tested at the LPC-CAEN. Dedicated to ion-atom collisions studies and excited fraction measurements, the setup combines a projectile ion beam line, a target of cold rubidium atoms provided by a magneto-optical trap (MOT), and a recoil ion momentum spectrometer. In a test experiment using a beam of Na(+) projectiles, we demonstrate its capability to measure, with a very high signal over background ratio, fully differential cross sections in scattering angle, initial state, and final state of the system. We detail, in this work, features that had not been described previously in the literature: an extraction of the recoil ions transverse to the ion beam axis, and a fast switch for the MOT magnetic field. Advantages of transverse versus longitudinal extraction are discussed, and future possibilities for the setup are presented.