1. Does the NaI crystal alone provide any signal gain (amplification) during the conversion of X-ray photons to light photons?
2. The photocathode is integrated into the PMT rather than coupled to it (externally). Provide 2 major reasons for this configuration.
3. If the PMT voltage were reduced from 1000V to 800V, what would be the effects on the spectral shape? Explain.