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Title: Fano factor and the mean energy per ion pair in counting gases, at low x-ray energies

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.365787· OSTI ID:531747
; ;  [1]
  1. Department of Particle Physics, The Weizmann Institute of Science, 76100, Rehovot (Israel)

The mean energy per ion-pair (W{sub i}) and the Fano factor (F) are provided with high accuracy (2{percent} and 3{percent}-4{percent}, respectively), in C{sub 2}H{sub 6}, C{sub 3}H{sub 8}, i-C{sub 4}H{sub 10}, CH{sub 4}, DME, Ar/C{sub 2}H{sub 6}(20:80), Ar/i-C{sub 4}H{sub 10}(20:80) Ar/DME (20:80) and Ar/Xe/i-C{sub 4}H{sub 10}(66.6/16.7/16.7), in the x-ray energy range of 0.11{endash}1.5 keV. These parameters were extracted from precise measurements of the number and temporal distribution of x-ray induced electrons, accompanied by extended simulations of the detection process. A decrease in these parameters with increasing x-ray energy was observed, accompanied by sharp increases at x-ray energies just above some atomic shells. The effect is discussed in relation to Auger electron emission. A Penning process in Ar/C{sub 2}H{sub 6}(20:80) and Ar/i-C{sub 4}H{sub 10} (20:80) is observed on the basis of comparative measurements of W{sub i} and F in these mixtures and in the pure hydrocarbons. Ways are proposed for further improving the accuracy provided by the electron counting technique to better than 1{percent}. {copyright} {ital 1997 American Institute of Physics.}

OSTI ID:
531747
Journal Information:
Journal of Applied Physics, Vol. 82, Issue 2; Other Information: PBD: Jul 1997
Country of Publication:
United States
Language:
English