Electrode thickness measurement of a Si(Li) detector for the SIXA array

Abstract Cathode electrodes of the Si(Li) detector elements of the SIXA X-ray spectrometer array are formed by gold-palladium alloy contact layers. The equivalent thickness of gold in one element was measured by observing the characteristic L-shell X-rays of gold excited by monochromatised synchrotron radiation with photon energies above the L 3 absorption edge of gold. The results obtained at four different photon energies below the L 2 edge yield an average value of 22.4 ± 3.5 nm which is consistent with the earlier result extracted from detection efficiency measurements.