Analytical and experimental dosimetry techniques for calibrating a low energy X-ray radiation source

Abstract

This paper describes the method used to calibrate a largevolume continuous-wave x-ray radiation test chamber. The xray tube has a tungsten target and emits a bremsstrahlung xray spectrum with end point energies up to 160 keV. Analytical tools and experimental dosimetry techniques were developed to map the radiation field intensity and the resulting dose-deposition profiles in a variety of materials throughout the chamber. Three detector types (x-ray vacuum diodes, silicon PIN diodes, and PMOS FETs) were used to measure spectral intensity and dose deposition in silicon devices. CEPXS and PHOTCOEF electron-photon transport codes were used to calculate the incident spectral energy distribution and the energy deposition in the detector. Calculated and experimental diode detector responses agreed to within 10 percent over the full energy range. PMOS FETs were used to demonstrate the correlation between total-dose-deposited in the x-ray chamber and in the Cobalt-60 cell. The results of this effort provide dosimetry and analysis tools needed to perform ionizing radiation testing of large area (0.5m2) electronic subsystems.

Carbon Nanotubes for Radiation-Tolerant Electronics

“…Two ionizing radiation sources were used: (1) 60 Co γ-ray source for TID tests from 0 to 800 Krad­(Si) (Figure i) and (2) a low-energy X-ray radiation (LEXR) source for TID tests up to 10 Mrad­(Si) (Figure j). While 60 Co is a conventional ionizing radiation source for TID tests, LEXR is capable of delivering much higher doses in shorter time intervals, thus enabling TID testing > 10 Mrad­(Si) (Kirkland AFB has previously demonstrated device response to LEXR correlates strongly with device response to 60 Co for all X-ray energies) . In addition, we perform additional TID testing to validate LEXR extrapolation above 60 Co (refer to Supporting Information to see continuity of the | V T shift| as the TID source changes from 60 Co to LEXR for CNFETs).…”

“…While 60 Co is a conventional ionizing radiation source for TID tests, LEXR is capable of delivering much higher doses in shorter time intervals, thus enabling TID testing > 10 Mrad(Si) (Kirkland AFB has previously demonstrated device response to LEXR correlates strongly with device response to 60 Co for all X-ray energies). 35 In addition, we perform additional TID testing to validate LEXR extrapolation above 60 Co (refer to Supporting Information to see continuity of the |V T shift| as the TID source changes from 60 Co to LEXR for CNFETs). Figure 2e−h show a typical CNFET chip containing an array of CNFETs for TID characterization.…”

Monte Carlo simulations for 20 MV X-ray spectrum reconstruction of a linear induction accelerator

“…An X-ray is generated when a high-energy electron beam is made to strike a high-Z target. There is an increasing demand to acquire a good knowledge of the X-ray spectral distribution, since it is tremendously significant for diagnostic X-ray imaging applications, such as beamhardening correction [3], dose deposition calculation [4], duel-energy material detection [5], etc. Because the X-ray emitted in short pulses from the Dragon-I LIA is of high intensity and dose rate, it is very difficult to make direct measurement of the X-ray spectra.…”