Figure 1. Characterization of the BNCD membranes.

(a) Experimental set-up. The BNCD membranes were tested under vacuum for electron emission and thickness measurements. Electrical pulses induced by α-particle hits were acquired simultaneously from both CEM (channel electron multiplier) and thick silicon detectors. (b) Impact of the BNCD membranes on the transmitted energy. The red spectrum shows the energy transmitted through a 150 nm thick commercially available Si₃N₄ window. The two BNCD membranes (blue and green spectra) induce the same energy loss, thus the overlapped spectra. The black curve shows the beam energy without any material in its path. When passing through the BNCD membranes, an average energy loss of 200 keV is measured. (c) Channeltron pulse height spectra. The channeltron output signal is clearly separated from background for both BNCD membranes. The red curve shows the spectrum obtained on a Si₃N₄ window without any coating.