73 The singlePE transittime spread measured for the $\LAPPD$ stack inside the 8" chamber, derived using the gaussian fit method. The RMS of the arrival times is 63 psec, and the fitted sigma is 56 psec.

72 The singlePE transittime spread measured for the $\LAPPD$ stack inside the 8" chamber, derived using the CFD algorithm. The RMS of the arrival times is 67 psec, and the fitted sigma is 56 psec. Given the inherent limitations of these fit methods, the nonGaussian character of the reconstructed TTS and wider tails compared to the template fit are expected.

71 An example oscilloscope trace including both the trigger diode and the UV photodiode.

70 An example of an MCP pulse.

69 he pulse height distribution for a pair of MCPs in single PE mode, overlaid with a polynomial fit to the shape.

68 A pair of demountable tile bases from Joe Gregar (ANL Glass Shop). These consist of a glass sidewall fritted onto a 30strip `Frugal' glass anode and are used with an Oring sealed window to test the MCPspacer stack of the Frugal tile at the APS laser facility. The pump ports are reinforced for mechanical strength.

67 Frequency spectrum of the MCP signal plus noise (solid red) overlaid on the pure noise spectrum (dashed blue). Signal dominates over noise only up to around 500 MHz.

66 A schamatic illustration of the 8" MCP testchamber.

65 Probability of the Ti::Sapphire laser pulse generating an MCP signal on the aluminum photocathode, plotted as a function of pulse energy. At sufficiently high laser intensities, this probability approaches unity; as the laser is attenuated below roughly 10 million UV photons per pulse, the fraction of laser pulses producing an MCP signal begins to drop and eventually approaches zero.

64 Differential time resolution as a function of
Noise/Signal, plotted for data collected using the Demountable detector in 2014 (red squares)
and the 8" chamber in 2012 (black circles). Error bars are smaller than the marker size. The intercept of fitted line intersects at 1.6 psec.
