Accession Number : ADA525359


Title :   Hard Collisions in Rubidium using Sub-Doppler Spectroscopy


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Thornton, Douglas E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a525359.pdf


Report Date : Mar 2010


Pagination or Media Count : 146


Abstract : To better understand the laser kinetics of an alkali gain medium, hard collisions, or velocity-changing collisions, has been studied and a velocity-changing collisional rate has been calculated. Previous works have studied these collisions, but no rate has been calculated. Using the precise tool of sub-Doppler spectroscopy, atomic hard collisions can be observed. The collected spectra are fitted with two different line shapes to demonstrate the accuracy of this method. From the fits, the number of hard collisions can be extracted. The time scale of the hard collisions in rubidium is interpolated by varying the chopping frequency of the pump beam, or how long the collisions are being observed. Using the time scale and the collisional information from the fits, the velocity-changing collision rate was determined to be 1020:7 + or - 26:3s-1mTorr-1 for the first line shape and 758:81 + or - 13:90s-1mTorr11 for the second line shape, which is a 17% and 13% difference, respectively, of the chemical kinetic hard sphere collisional model rate, 872:78 + or - 13:73s-1mTorr-1.


Descriptors :   *RUBIDIUM , *COLLISIONS , *VELOCITY , DIODE LASERS , THESES , SPECTROSCOPY , DOPPLER SYSTEMS


Subject Categories : Lasers and Masers
      Metallurgy and Metallography
      Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE