Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Ionization Increase in Miniaturized IMS Cell Using a Thin Layer on Am-241 Ionization Source

Document Type : Research Paper

Authors

M Salehkoutahi
F Payervand
A Tavassoli
Abstract
One of the important goalsin chemical agent detection is to construct an instrument with a fast response, to be handled easily, and to be used in various operational conditions. In this paper, based on the phenomenon of “increasing the specific alpha particles ionization rate by decreasing the particles energy” a suggestion has been made for reducing the size of the ionization chamber of an IMS detection system, where a thin layer was placed on the surface of Am-241 ionizing source for decreasing the emitted alpha particles energy. With this method, to some extent, the rate of ionization loss has been compensated. The effect of layer over the Am-241 source on the ionization rate has been predicted theoretically, as well. For the other two sources with the initial coated layers, a calculation has been performed with the use of the related energy distribution; and the effect of a layer, of the Mylar type, on the ionization rate has also been investigated. The results of both cases have shown that the layer will cause to increase the ionization rate in the ionization chamber, where it subsequently increases the capability of the instrument, and the system resolution power for detecting various chemical agents.

Highlights

  1. G.A. Eiceman and Z. Arpas, “Ion mobility spectrometery,” CRC Press (1994).

     

  2. R. Schnurpfeil (Bremen, DE) and S. Klepel (Taucha, DE), United State Patent, Patent number 6064070 (May 16, 2000).

     

  3. G.F. Knoll, “Radiation detection and measurement,” John Wiley & Sons, 9 (1988).

     

  4. H.H. Andersen and J.F. Ziegler, “Hydrogen: stopping powers and ranges in all elements,” The Stopping and Ranges of Ions in Matter,  3, Pergamon Press, Elmsford, New York (1977).

     

  5. A. Nazarov and D. Thierry, “Rate determining mractions of atmospheric corrosion,” Electrochimica Acta, Volume 49, Issues 17-18, 2717-2724 (30 July 2004).

     

  6. A. Tavassoli, M. Salehkootahi, F. Payervand, “Determination the spectrum of alpha source of the NDCAM detector with an ordinary alpha counter,” 2nd International Conference On Nuclear Science and Technology, 36, April 27-30 (2004).

Keywords

ion mobility spectrometer instrument
Am-241 ionization source
alpha particles
stopping power
mylar
ionization chambers

  1. G.A. Eiceman and Z. Arpas, “Ion mobility spectrometery,” CRC Press (1994).

     

  2. R. Schnurpfeil (Bremen, DE) and S. Klepel (Taucha, DE), United State Patent, Patent number 6064070 (May 16, 2000).

     

  3. G.F. Knoll, “Radiation detection and measurement,” John Wiley & Sons, 9 (1988).

     

  4. H.H. Andersen and J.F. Ziegler, “Hydrogen: stopping powers and ranges in all elements,” The Stopping and Ranges of Ions in Matter,  3, Pergamon Press, Elmsford, New York (1977).

     

  5. A. Nazarov and D. Thierry, “Rate determining mractions of atmospheric corrosion,” Electrochimica Acta, Volume 49, Issues 17-18, 2717-2724 (30 July 2004).

     

  6. A. Tavassoli, M. Salehkootahi, F. Payervand, “Determination the spectrum of alpha source of the NDCAM detector with an ordinary alpha counter,” 2nd International Conference On Nuclear Science and Technology, 36, April 27-30 (2004).

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