Recent Developments with Microchannel-Plate PMTs


Lehmann, A., Böhm, M., Britting, A., Eurich, W., Pfaffinger, M., Uhlig, F., Belias, A., Dzhygadlo, R., Gerhardt, A., Götzend, K., Kalicy, G., Krebs, M., Lehmann, D., Nerling, F., Patsyuk, M., Peters, K., Schepers, G., Schmitt, L., Schwarz, C., ... & Achenbach, P. (2016). Recent Developments with Microchannel-Plate PMTs.


  • Cherenkov detectors
  • microchannel-plate photomultipliers
  • lifetime
  • atomic layer deposition (ALD)


Microchannel-plate photomultipliers (MCP-PMTs) have significantly improved longevity due to atomic layer deposition (ALD) coating techniques, making them suitable for long-term use in high-energy physics experiments. While earlier MCP-PMTs suffered from rapid aging, particularly in their photocathodes, ALD coatings have led to a greater than 50 times improvement in lifespan. These findings are based on research conducted for the PANDA experiment at the FAIR facility, where MCP-PMTs are vital for detecting photons within the DIRC detectors.


This article presents a study on the lifetime improvement of microchannel-plate photomultipliers (MCP-PMTs) using atomic layer deposition (ALD) coating technology.

  • MCP-PMTs are essential for detecting single photons in high magnetic fields, making them crucial for experiments like the PANDA experiment at FAIR.
  • The lifetime of MCP-PMTs is limited by aging effects, primarily the decrease in quantum efficiency (QE) of the photocathode as the integrated anode charge (IAC) increases.
  • ALD coating of MCPs significantly enhances their lifetime by mitigating aging effects.
  • The authors conducted aging tests on ALD-coated MCP-PMTs from PHOTONIS and Hamamatsu, demonstrating a lifetime improvement exceeding 50 times compared to older MCP-PMT models.
  • The study highlighted the performance of a new 2-inch ALD-coated MCP-PMT prototype from Hamamatsu, which boasts high position resolution but exhibits a faster QE degradation rate compared to other ALD-coated models.
  • Further research is underway to understand the aging mechanisms in MCP-PMTs fully.

The authors also investigated the aging mechanisms in a half-aged PHOTONIS MCP-PMT and found that while ion feedback is a significant contributor to aging, simple work function arguments alone can't fully explain the observed QE degradation.


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