The energy distribution of an ion in a radiofrequency trap interacting with a nonuniform neutral buffer gas

Rouse, Ian and Willitsch, Stefan. (2019) The energy distribution of an ion in a radiofrequency trap interacting with a nonuniform neutral buffer gas. Molecular Physics, 117 (21). pp. 3120-3131.

[img] PDF - Submitted Version

Official URL: https://edoc.unibas.ch/74467/

Downloads: Statistics Overview


An ion in a radiofrequency (rf) trap sympathetically cooled by a simultaneously trapped neutral buffer gas exhibits deviations from thermal statistics caused by collision-induced coupling of the rf field to the ion motion. For a uniform density distribution of the buffer gas, the energy distribution of the ion can be described by Tsallis statistics. Moreover, runaway heating of the ion occurs if the buffer gas particles are sufficiently heavy relative to the ion. In typical experiments, however, ultracold buffer gases are confined in traps resulting in localised, non-uniform density distributions. Using a superstatistical approach, we develop an analytical model for an ion interacting with a localised buffer gas. We demonstrate theoretically that limiting collisions to the centre of the ion trap enables cooling at far greater mass ratios than achievable using a uniform buffer gas, but that an upper limit to the usable mass ratio exists even in this case. Furthermore, we analytically derive the functional form of the energy distribution for an ion interacting with a buffer gas held in a harmonic potential. The analytical distribution obtained is found to be in excellent agreement with the results of numerical simulations.
Faculties and Departments:05 Faculty of Science > Departement Chemie > Chemie > Chemische Physik (Willitsch)
UniBasel Contributors:Rouse, Ian and Willitsch, Stefan
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Taylor & Francis
Note:Publication type according to Uni Basel Research Database: Journal article
Related URLs:
Identification Number:
edoc DOI:
Last Modified:04 Feb 2020 11:13
Deposited On:04 Feb 2020 11:13

Repository Staff Only: item control page