Experimental study on rotational temperatures in nitrogen molecular beam

Hiroki Yamaguchi, Tatsuya Moriyama, Kyohei Ide, Jun Ito, yu Matsuda, Tomohide Niimi

Research output: Contribution to journalArticle


Rotational energy distribution in a nitrogen molecular beam was experimentally studied by (2+2) N 2-REMPI(Resonantly Enhanced Multiphoton Ionization). REMPI is known to have high detection sensitivity, which allows obtaining the signal under the very low number density condition like a molecular beam, successfully. Obtained REMPI spectrum was fitted by a theoretical spectrum to determine rotational temperature. The spectrum was well fitted, showing the rotational energy distribution obeyed the equilibrium Boltzmann distribution. The rotational temperature in a molecular beam must be similar to the frozen rotational temperature in a free jet, since a free jet is used as a beam source in the Kantrowitz-Grey type. The parameter p 0d, which is a product of the source pressure p 0 and the orifice diameter d, is known to characterize a free jet. Therefore, the rotational temperature in a molecular beam was analyzed in terms of the parameter p 0d. The rotational temperature was able to be described by the power of the parameter p 0d. The rotational temperature and the obtained function were compared with the value in literatures, which showed good agreement.

Original languageEnglish
Pages (from-to)282-291
Number of pages10
JournalNihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Issue number774
Publication statusPublished - 2011 Dec 1
Externally publishedYes



  • High knudsen number flow
  • Molecular beam
  • Nonequilibrium
  • Rotational temperature

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering

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