کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
748834 1461894 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A current controlled miniaturized non-radioactive electron emitter for atmospheric pressure chemical ionization based on thermionic emission
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
A current controlled miniaturized non-radioactive electron emitter for atmospheric pressure chemical ionization based on thermionic emission
چکیده انگلیسی


• Non-radioactive electron source as an alternative to radioactive beta minus sources.
• Controllable atmospheric pressure ionization source.
• Electron transfer from vacuum to atmospheric pressure.

In this paper, we introduce a simple to manufacture, emission current controlled, miniaturized non-radioactive electron source to provide free electrons at atmospheric pressure. In atmospheric pressure chemical ionization as usually used in ion mobility spectrometry radioactive beta minus sources provide free electrons with high kinetic energy to initiate a chemical gas phase ionization of the analytes. Here, classical thermionic emission from a heat controlled tungsten filament in vacuum is used to generate free electrons. These are then accelerated towards an electron transparent 300 nm thin Si3N4-membrane through which the electrons are transferred from vacuum to atmospheric pressure. Both, the emitted electron current and the average kinetic electron energy can be controlled. For similar ionization processes as compared to radioactive beta minus sources we operate the electron source with an electron emission current at atmospheric pressure of 50 pA – corresponding to an activity of 300 MBq – and an average kinetic electron energy of 8.6 keV.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sensors and Actuators A: Physical - Volume 206, 1 February 2014, Pages 165–170
نویسندگان
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