A comparison of the performance of high QE photomultiplier tubes to conventional photomultiplier tubes

We have carried out experiments to assess the performance advantage of high quantum efficiency (HQE) photomultiplier tubes (PMTs) over conventional PMTs for possible use in a cardiac SPECT system. In particular, we have conducted tests of pulse height resolution and position sensitivity of HQE PMTs and compared their performance to conventional PMTs. Furthermore, we have conducted a cathode sensitivity scan and pulse height resolution scan of four HQE PMTs and four conventional PMTs. The HQE PMTs outperformed the conventional PMTs in both pulse height resolution and position sensitivity. Finally, we tested the four HQE PMTs on a 3 mm × 3 mm pixellated NaI(Tl) detector module and were able to resolve the pixels with 8.3% average energy resolution.