We have used the pulse from the generator with 5ns risetime and variable amplitude. The output was splitted to 4 signals: two different channels in CFD and 2 different
signals in ADDON.
Next figure shows the time walk of signals from the leading edge discriminator (ADDON) as TOT1 versus time1-time2. Time2 comes from the signal with high amplitude
of 500-1200mV (with good timing), time1 and TOT1 from the same signal attennuated by 1:2 and 1:4 with amplitudes 600-125mV. The shift in two sets of data is caused by adding the additional attenuator.
- time above threshold versus time difference between 2 TRB channels (file to08330110244):
Figure below shows the time resolutions for signal with fixed amplitude 600 mV. Upper left: TOT vs time_LED_1 - time_CFD_1 , upper right: time_LED_1 - time_CFD_1
lower left: time_LED_2 - time_LED_1 lower right: time_CFD_2 - time_CFD_1. The resolution for CFD2-CFD1 is 80 ps, LED2-LED1 within one TRB channel (100 ps),
LED1-CFD1 has resolution 140 ps. It can reflect the difference in providing the start time for TDC and the reference time for TRB, respectively.
On the basis of this measurement we cannot expect better resolution in our cosmics test.
- time resolution of pulses from the generator (file to08329173659):
- 26 Nov 2008