Forensic methodology for the thermochemical characterization of ANNM and ANFO mixture homemade explosives

Published

April 9, 2015

Author(s)

Ashot Nazarian, Cary Presser

Abstract

Experimental measurements were carried out using a novel laser-heating technique with the most commonly used HME mixture materials, i.e., ammonium nitrate/nitromethane and ammonium nitrate/No. 2 diesel fuel oil, for different compositions, initial masses, and steady-state temperatures, along with the effects associated with HME aging. For ANNM, the NM/ANNM mass fractions investigated were 29 % (stoichiometric value) and 14 %; these experiments were with fresh mixtures. The 29 % NM/ANNM mass fraction mixture was also aged to 3 %. For ANFO, a fresh stoichiometric FO/ANFO mass fraction of 6 % was used initially, and aged mixtures were then investigated for mass fractions of 5.4 %, 4.7 %, 4.4 %, and 3.7 %. The results indicated that the thermograms (i.e., sample temperature change with time) for the mixed ANNM were different than the individual isolated components, and that the technique is sensitive to varying HME composition. In addition, the LDTR thermograms for aging ANFO change with time due to the varying volatility of the fuel hydrocarbon fractions, and thus provide important information for forensics analysis as to the HME probability of detonation.

Citation

Thermochimica ACTA

Pub Type

Journals

Keywords

ammonium nitrate, homemade explosives, fuel oil, laser-driven thermal reactor, nitromethane, thermochemical, thermo-physical, thermal signatures

Citation

Nazarian, A. and Presser, C. (2015), Forensic methodology for the thermochemical characterization of ANNM and ANFO mixture homemade explosives, Thermochimica ACTA (Accessed May 5, 2024)