Load capacity and recovery behavior of ALD-coated MCP-PMTs

We report the saturation and recovery properties of ALD-coated MCP-PMTs produced by Hamamatsu Photonics K.K. and Photek Ltd. compared to a non-ALD device produced by Photonis, Inc. Similar study has been done previously for ALD-coated Photonis MCP-PMTs. The obtained results confirm that ALD-coated MCP-PMTs produced by any of these manufacturers feature an unexpectedly long time needed for the gain recovery once the saturation was reached (from few minutes up to more than an hour). Despite the saturation level in terms of the average anode current for such devices may reach 0.4 μA/cm2 their use in high load accelerator-based experiments requires additional precaution to avoid driving an MCP-PMT to a saturated mode even for a short time before the start of any data taking period.