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Applying the pulsed ion chamber methodology to full range reactor ...

Applying the pulsed ion chamber methodology to full range reactor ...

where; E -

where; E - the average energy deposited in the gas per neutron interaction, w = the mean eneryy required to create an electron-ion pair, a ~ average neutron interaction cress section, iy = atom density of the neutron sensitive material, a $ - the flux density in the vicinity of the detector, g = gas ionization efficiency which is for a given radiation field arid chamber design I : - gamma source intensity. The ion source rate, S, is directly relatable to the relatively easily measured experimental valve I , the steady state ionization current. 1 c is measured by applying a constant collection potential to chamber electrodes erA measuring the current between those electrodes which result from the ionizing radiation. In Darticular, eli " (2-9) where, e = the unit of electronic charges U = the sensitive volume of the chamber. Equations 2-4 through 2-9 thus provide a direct, relatively simple rela- tionship between the PIC output signal v(t ) and the ionizing radiation field strengths, and, as such, serve as the theoretical basis for this entire endeavor. With the aid of the author, detailed numerical caicula tior.s were performed by Meravi for a miniature fission chamber filled with neon and argon, Some of the results, are presented in figures 2-2 through 2-5.. The curves in figures 2-2 and 2-3 represent the radial 16

A.;i.sueG uoi aAnLSOd pazL[euyoM E -