Abstract

In this paper, we report the use of photoacoustic and reflectance spectroscopy to obtain the infrared spectrum of HMX powder (beta-cyclotetramethylene tetranitramine), and we compare these spectra with the transmission spectrum of a single crystal of HMX. These spectra are then used to determine the best region of overlap between HMX absorption and CO₂ laser emission lines in the infrared. Figure 1 shows the spectrum obtained by using the photoacoustic detector from 3500 to 400 cm⁻¹ and the reflectance and transmission spectra from 3500 to 700 cm⁻¹ for HMX. Figure 2 shows the overlap between CO₂ infrared laser frequen­cies¹ and HMX absorption frequencies (in reflec­tance) from 900 to 1100 cm⁻¹. The intensities shown for the CO₂ laser transitions are based on the thermal distribution among rotational states al 300 K, so they should be used only as a rough guide. However, this distribution agrees fairly well with previously observed intensity distributions.²

© 1991 Optical Society of America