Mylar vs ESR

1) Amplitude of the signals



Previously, we have compared ESR wrapping with Tyvek, Aluminum foil and no wrapping at all. ESR was giving us about 45% larger signal than either Tyvek or foil (plot on the left). Back then, we didn't have Mylar to test which we have now. Because of the new trigger setup and new PMTs, direct comparison with previous measuremnts cannot be done. So, we measured only ESR and Mylar wrapping under the new conditions. ADC spectra shown below were taken at HV of 2000V and 1800V. At 2000V, peak positions are at 1801 counts (Mylar) and 2444 counts (ESR). At 1800V, they are at 1101(Mylar) and 1472(ESR). Taking into account pedestal position at 267 counts, ESR signals exceeds Mylar by (2444-267)/(1801-267)=1.42 at 2000V and by (1472-267)/(1101-267)=1.45 at 1800V. Rescaling ESR peak to its position in the old measurement will put Mylar peak at about 801 counts on the first plot, i.e., on par with Tyvek.
MylarESR

2) Timing resolution

Timing resolution calculated with 6-PMT method are comparable between ESR and Mylar, with just a slight ESR advantage (125.1ps vs 130.3ps)
MylarESR
Sigma = sqrt(3.022^2 - 2.768^2/2) = 2.30 counts = 130.3ps Sigma = sqrt(2.815^2 - 2.463^2/2) = 2.21 counts = 125.1ps