Photoassociative Spectroscopy of Ultracold Metastable Argon and Study of Dual Species Trap Loss in a Rubidium-Metastable Argon MOT

<p>This dissertation presents the findings of two experimental investigations in ultracold atomic and molecular physics: The study of the dual species trap loss in a rubidium - metastable argon magneto-optical trap and the photoassociative spectroscopy of ultracold metastable argon. The interspecies trap loss rate coefficients have been measured for ultracold collisions between ⁸⁵Rb and ⁴⁰Ar* in a dual-species magneto-optical trap (MOT) and the two rates have been found to be approximately equal over the range of intensities studied with values of β'<em>_Rb–Ar* </em>= 3.0 ± 1.3 × 10^-11 cm³/s and β'_{<em>Ar*–Rb</em>} = 1.9 ± 0.9 × 10^-11 cm^3/s where β'<em> _Rb–Ar*</em> is the trap loss coefficient for Rb in the presence of Ar* and β'_{<em>Ar*–Rb</em>} is the reciprocal term. In addition, the trap loss rate coefficient for cold collisions in a metastable argon MOT alone have been measured with an average value of β<em> _Ar*</em> = 5.2 ± 1.6 × 10^-10 cm³/s. Using a quadrupole mass spectrometer, the production of Ar +, Ar⁺², Rb⁺, and RbAr⁺ ions in the dual MOT have been observed, clearly identifying heteronuclear Penning and associative ionization as trap loss mechanisms. In the second experiment, the first ever investigation of the photoassociative (PA) spectroscopy of Ar* has been made. The exploratory study focuses on PA spectroscopy near the 4s[3/2]₂ + 4p[5/2]₃ asymptote of the Ar₂* diatomic molecule over a 10 GHz range red detuned of the atomic resonance. With a range of probe laser intensities from ∼ 10²–10⁵<em>I_Sat</em>, 12 resonances have been observed. The spectra have been analyzed using the near-dissociation LeRoy-Bernstein method. Through this analysis, the spectra seem to best correlate with excitations to the 5_<em>g</em> state.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date.available

2008

Author dc:creator

• Shaffer, Michael K.

Contributors dc:contributor

• Charles I. Sukenik
• Mark D. Havey
• Gilbert R. Hoy
• J. Wallace Van Orden
• John R. Donat

• Argon
• Magneto-optical traps
• Metastable argon
• Rubidium
• Species trap loss
• Ultracold atoms
• Atomic, Molecular and Optical Physics

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Identifier

9780549857006

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:physics_etds-1079