14N NQR, relaxation and molecular dynamics of the explosive TNT
| Autor: | John A. S. Smith, Jamie Barras, Michael D. Rowe, Kaspar Althoefer, Neil Francis Peirson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Nuclear and High Energy Physics
Radiation Explosive material Pulsed spin-locking (PSL) sequence Chemistry Relaxation (NMR) Analytical chemistry General Chemistry Activation energy NQR parameters TNT detection NQR relaxation times Temperature variation Molecular dynamics Orthorhombic crystal system Multiple pulse Instrumentation N NQR Line (formation) Monoclinic crystal system |
| Zdroj: | Smith, J A S, Rowe, M D, Althoefer, K, Peirson, N F & Barras, J 2015, ' 14 N NQR, relaxation and molecular dynamics of the explosive TNT ', Solid State Nuclear Magnetic Resonance, vol. 71, pp. 61-66 . https://doi.org/10.1016/j.ssnmr.2015.09.009 |
| DOI: | 10.1016/j.ssnmr.2015.09.009 |
| Popis: | Multiple pulse sequences are widely used for signal enhancement in NQR detection applications. Since the various 14N NQR relaxation times, signal decay times and frequency of each NQR line have a major influence on detection sequence performance, it is important to characterise these parameters and their temperature variation, as fully as possible. In this paper we discuss such measurements for a number of the ν+ and ν- NQR lines of monoclinic and orthorhombic TNT and relate the temperature variation results to molecular dynamics. The temperature variation of the 14N spin-lattice relaxation times T1 is interpreted as due to hindered rotation of the NO2 group about the C-NO2 bond with an activation energy of 89 kJ mol-1 for the ortho and para groups of monoclinic TNT and 70 kJ mol-1 for the para group of orthorhombic TNT. |
| Databáze: | OpenAIRE |
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