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

Abstract

A crossed atomic–molecular beam apparatus has been used to measure the collisional energy dependences of the total scattering cross section σ T and the chemiluminescent reaction cross section σ r 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, σ T decreases by about a factor of 3 in the Ho atom energy range from 0.5–3.5 eV, whereas σ r increases by about a factor of 2 in the same energy range. For B+N2O, σ T is of nearly constant magnitude in the 1–4 eV B atom energy range; however, σ r increases by a factor of ten in this energy range. The comparison of results obtained with thin and thick target gases indicates that σ r ≪σ T for both the Ho+N2O and B+N2O interactions.