|
ИСТИНА |
Войти в систему Регистрация |
Интеллектуальная Система Тематического Исследования НАукометрических данных |
||
Effects of matrix state on the laser-induced plasma parameters for soils and oresтезисы доклада
- Авторы: Popov A.M., Labutin T.A., Zaytsev S.M., Zorov N.B.
- Сборник: 9th International Conference on Laser-Induced Breakdown Spectroscopy (LIBS 2016), Abstracts
- Тезисы
- Год издания: 2016
- Место издания: Université Claude Bernard Lyon 1 Lyon
- Первая страница: P123
- Последняя страница: P123
- Аннотация: Since LIBS is a direct analytical technique, strong matrix effects are often observed for LIBS analysis of powdered materials such as soils, ceramics, ores, etc. Understanding the reasons resulting in the matrix effects is a key to reduce or diminish their influences on analytical results. Researchers usually prepare pressed pellets to analyze dried powders. Our goal is to estimate the influences of the pressing pressure and humidity on plasma temperature T and electron density Ne. We have used a set of soils and iron-manganese nodule (OOPE 604) as certified reference material of pelagic sediments. According to their Certificate, the material represents itself a fine-dispersed powder with the particle sizes less than 50 μm. Since we have used the same material to prepare pellets, the obtained results are independent from the dispersity and mineral composition of the sample, and, therefore, it ensures that the observed relationship will be relevant through all types of powdered samples. To study the effect of pressing pressure on the plasma properties, we have prepared a set of pellets with diameter of 12 mm under the different pressure provided by the hydraulic press machine. The range of pressure was varied from 160 kg/cm2 to 10 ton/cm2. A piece of sticky tape covered with grains of the powder was used as a simulator of non-pressed powder, i.e. no pressure was applied to the sample, in order to avoid flying away the grains. One-layer of grains clinging close each to other was produced on the sticky surface of scotch. We have observed that plasma parameters did not depend on pressing pressure at the shortest delay (500 ns) while there was an evident growth of T and Ne with pressure increase for longer delays (7.5 μs). Since the intensity of Mn I and Fe I lines had similar relationships on pressing pressure, we explained such matrix effects by the differences of ablation rate and the velocity of ablated particles in a plume. To study humidity effects, the set of soils containing different amount of water was prepared. We have observed the suppression of Ne and T with the increase of soil humidity.
- Добавил в систему: Лабутин Тимур Александрович