Study on emission spectroscopy and flame of boron combustion in different atmosphere

In order to reveal the combustion characteristics of amorphous boron powder in different atmosphere, experimental studies were carried out using a laser ignition system. Visible wavelength emission spectra and burning flame were recorded using a spectrometer coupled with a high speed camera. The results show amorphous boron can maintain self burning in pure N₂ with light yellow flame, while the combustion in pure O₂ is much stronger with a green flame. Spectroscopic data taken in pure O₂ show obvious BO₂ emission and little BO emission, while those taken in pure N₂ show no BN emission. The highest intensity peak of the emission spectrum of the gas-phase reactant BO₂ is at wavelength of 547.1 nm. No BO₂ emission is detected in O₂/H₂O environment compared to O₂. As the mole fraction of O₂ decreases, the BO₂ peaks at the wavelengths of 471, 492.9, 518.1, 547.1, 579.1 nm are always strong, whereas those of 452 and 620.2 nm gradually fade away in O₂/N₂ environment.