Temporal evolution of absorption spectra for diisopropyl methylphosphonate at high temperatures in a shock tube

Abstract

Absorption spectra and cross-sections of Diisopropyl Methylphosphonate (DIMP) are measured in argon at temperatures of 600–1250 K in a shock tube using rapid scanning, broadband absorption spectroscopy. Measurements are obtained at approximately 2.3 kHz with each complete scan of the 925–1350 wavenumber band taking 90 microseconds. This technique enables spectra behind incident and reflected shocks to be obtained in a single test. In addition, multiple spectra are obtained behind the reflected shock during the test time. A significant reduction in absorption cross section with temperature is observed, and the spectra taken during the test time show no decomposition or significant changes, suggesting that vibrational equilibrium is achieved.

Keywords:

• Absorption cross section
• absorption spectroscopy
• Diisopropyl Methylphosphonate
• high temperature
• shock tube

Acknowledgments

The Defense Threat Reduction Agency (DTRA) is an agency with the U.S. Department of Defense (DOD) that works to counter weapons of mass destruction (WMD). This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in this paper do not necessarily represent the views of the DOD or the United States Government. The authors would like to acknowledge Neil Thakker, Lisa Mirsaliyeva, Paul Raducha, and Jun Shin for contributions to shock tube laboratory operation.

Disclosure statement

The authors declare that they have no known competing financial interest or personal relationships that could have influenced the work reported in this paper.