Measurement of chemiluminescent reaction cross sections for B+N2O→ BO*+N2 and Ho+N2O→HoO*+N2

A crossed atomic–molecular beam apparatus has been used to measure the collisional energy dependences of the total scattering cross section σT and the chemiluminescent reaction cross section σr for holmium and boron atoms interacting with N2O molecules. The laser vaporization of metal foils is used to produce a metal atom beam pulse with energies ranging between ∼0.5 and 4 eV. The target gas of N2O molecules is generated by a room temperature nozzle beam. The chemiexcitation of electronic states of the metal oxides formed in the B+N2O→BO*+N2 and Ho+N2O→HoO*+N2 reactions is assumed to be the source of the observed visible radiation. For the Ho+N2O interaction, σT decreases by about a factor of 3 in the Ho atom energy range from 0.5–3.5 eV, whereas σr increases by about a factor of 2 in the same energy range. For B+N2O, σT is of nearly constant magnitude in the 1–4 eV B atom energy range; however, σr increases by a factor of ten in this energy range. The comparison of results obtained with thin and thick target gases indicates that σr≪σT for both the Ho+N2O and B+N2O interactions.