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  • X-Ray Ion Mobility Spectrometer
    For the ionization of gaseous samples, most ion mobility spectrometers employ radioactive ionization sources, e.g. containing 63Ni or 3H. Besides legal restrictions, radioactive materials have the disadvantage of a constant radiation with predetermined intensity. The aim of this research project is the realization and characterization of an X-ray IMS. Therefore, the 3H-source of our previously described compact high resolution IMS was replaced by a commercially available X-ray source. The realized setup maintains the high resolving power of R = 100 at a drift length of 75 mm and shows very good detection limits in the low pptv-range.
    Jahr: 2016
  • Shutterless IMS
    The use of non-radioactive electron sources for ionizing the target analytes in Ion Mobility Spectrometers (IMS) can lead to new application options. For example, our electron source can be operated in a fast pulsed mode. By optimizing the geometric parameters and developing fast control electronics, we can achieve very short electron pulses for ionization with high intensities, and an adjustable pulse width of down to a few nanoseconds. This results in small ion packets at simultaneously high ion densities. By omitting the separate reaction chamber the ion packet can be generated directly at the beginning of the drift tube with only slight reduction in resolving power. Thus, the complex and costly shutter mechanism and electronics can also be omitted, which leads to a simple low cost IMS-system with a pulsed non-radioactive source, and a resolving power of 70 to 80.
    Jahr: 2016
  • Data acquisition software for ion mobility spectrometers
    In order to control all parameters of a measurement setup, carry out automated measurements and analyze the generated data, a custom software suite has been developed using LabVIEW. It allows direct control of both our custom-built bus system as well as external devices, acquires and stores ion mobility spectra together with all relevant measurement parameters and allows the user to implement additional custom functions through a special scripting language.
    Jahr: 2016
  • Measurement electronics
    Virtually every measurement setup requires various control signals and a data acquisition system in order to function. The performance of these devices has a significant impact on the overall performance of the entire measurement setup. Thus, crucial components such as fast high voltage switches or picoampere amplifiers as well as a modular bus system were developed and manufactured in-house.
    Jahr: 2016
  • Non-radioactive electron sources for fast high sensitive sensor systems
    Most ion mobility spectrometers (IMS) employ a radioactive β-source to ionize the target analytes. However, because of the potential hazards and the associated handling restrictions regarding radioactive materials non-radioactive ionization sources are of increasing importance. The aim of this research project is the development of non-radioactive electron sources, which are used both in ion mobility spectrometry for ionization as well as in other sensor systems. Here, one advantage is that non-radioactive electron sources generate identical ion species as radioactive electron sources. A further advantage of non-radioactive electron sources is the controllability of the electron emission and hence the ionization process and the consequent opportunity to develop completely new sensor principles.
    Jahr: 2016
    Förderung: This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13N12820.
  • Electron capture detector with non-radioactive electron source
    Gas chromatographs equipped with electron capture detectors (ECD) are widely used for the analysis of electron affine substances such as pesticides, herbicides or chlorofluorocarbons. Achieving limits of detection in the low pptv-range, electron capture detectors are the most sensitive detectors available for such compounds. Based on their operating principle, they require free electrons at atmospheric pressure, which are usually generated by using a β--decay. However, the use of radioactive materials leads to regulatory restrictions regarding purchase, operation and disposal. Therefore, we developed a new electron capture detector using our non-radioactive electron source, which is not subject to these limitations and offers further advantages such as adjustable and higher electron densities and energies.
    Jahr: 2017