A study on REMPI as a measurement technique for highly rarefied gas flows (Analyses of experimental REMPI spectra in supersonic free molecular flows)

H. Mori, T. Ishida, Y. Aoki, T. Niimi

Research output: Contribution to journalArticle

2 Citations (Scopus)


A technique for measurement of thermodynamic variables with high sensitivity is necessary for analyses of highly rarefied gas flows, gas-surface interaction, and so on. REMPI (Resonantly Enhanced Multiphoton Ionization) is a powerful optical tool because of its high sensitivity even in highly rarefied gas flows and its ability to measure nonequilibrium amongst internal (translational, vibrational, and rotational) energy modes. In this paper, a REMPI system is developed and REMPI spectra are measured on the center line of a free-molecular flow. The fundamental properties of the REMPI signal are also described. A method using a Boltzmann plot with the spectral lines of multiple branches is proposed, and the ratio of the electronic transition dipole moments in the two-photon Hönl-London factors for the O and P branches is determined.

Original languageEnglish
Pages (from-to)388-394
Number of pages7
JournalJSME International Journal, Series B: Fluids and Thermal Engineering
Issue number3
Publication statusPublished - Aug 1 2001
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Physical and Theoretical Chemistry
  • Fluid Flow and Transfer Processes

Cite this