Saturation current of miniaturized fission chambers

Improvements in the Modeling of Sub-Miniature Fission Chambers Operated in Current Mode

“…In [4] and [8], we establish that the density, , can be approximated, in cylindrical geometry, by (4) shown at the bottom of the page, where and are, respectively, the anode radius and length. and are the cylindrical coordinates (see Fig.…”

“…is the mean number of electron-ion pairs created by the fission products per unit of length travelled in the gas. For sub-miniature detectors, the interelectrode gap is small, so that is constant, equal to [8]. Approximate values of are listed in Table I.…”

“…Approximate values of are listed in Table I. When the distance is small compared to is well approximated by (see [8]) where is a step function, equal to 1 when and zero everywhere else. The function is the complete elliptic integral of the first kind [9].…”

Assessment of fissionable material behaviour in fission chambers

“…It can be demonstrated that the activation structures has much more impact on the background current than the fission product activities comparing those parasitic currents in FCs with and without fissile deposit. The main effects of this residual ionization in FC are: (i) twisted calibration curve shapes and (ii) decreased voltage extensión of the saturation regime [11]. Consequently, the total radioactivity prediction can help to better understand the FC behaviour for a long-term performance.…”

Fission Chambers Designer Based On Monte Carlo Techniques Working in Current Mode And Operated in Saturation Regime

“…However, pure noble gases have unique physical properties, inert gases appear in mono atomic form, not molecular form, and thus do not undergo degradation because of radiation induced dissociation reactions [29]. Additionally, they present other interesting properties such as high stopping power, small Fano Factor, and relatively low energy required for electron-ion pairs and photon production in case of xenon and low Doppler broadening in Compton scatter in neon, among others.…”