Detailed characterization of low background $\beta $-delayed proton detector

In order to determine the rates of two important reactions for the astrophysical rapid proton (rp) capture process, a segmented, low background $\beta $-delayed proton detector has been built at NSCL. The detector is currently in the process of being optimized. A detailed characterization of the detector's Micromegas pad plane is being performed using measurements with a radioactive $^{\mathrm{55}}$Fe x-ray calibration source. A fitting routine has been developed to extract the energy resolution from the spectra. First results of detector resolution with P10 gas will be presented.