Calorimeter calibration First Delay Ramp Stephanie Beauceron LPNHE

Calorimeter calibration First Delay Ramp Stephanie Beauceron LPNHE – Paris 7/26/01

Delay Ramp pulse height increasing pulser delay -3 0 +3 time +6 sampling time with respect to trigger • 7 runs from 3 -early (-396 ns) to 4 -late (528 ns) • each ramp taken with 50 steps of 5 delay units and with 50 events by steps • DAC value = 20000 • Baseline Subtraction = -5 BC (instead of – 3 nominal) • Run in Fixed Cell and Unsuppressed Mode 7/26/01

Delay Ramp • Data analyzed with Cal_elec • 1 delay unit = 1. 66 ns • 1 run corresponds to 250 steps*1. 66 ns= 415 ns • distributions for crates 2 and 8 3 -early is 1 -late Not really conclusive 7/26/01 3 -early (- 396 ns) 1 -early (- 132 ns) 2 -early (- 264 ns) Nominal (0 ns) 1 -late (+ 132 ns) 2 -late (+ 264 ns) 4 -late (+ 528 ns) 3 -late (+ 396 ns)

Delay Ramp Mean and sigma of crate 2 for ADC card 0 depth 2 and 8 7/26/01 too high bad events Mean and sigma of crate 8 for ADC card 0 depth 2 and 8

Delay Ramp Considering this plots, some changes are tried: 3 -early => 1 -late 2 -early => 4 -early 1 -early => 2 -early 2 -late => 4 -late 3 -late and 4 -late out of considerations 7/26/01

Delay Ramp With a variation of the delay unit value =1. 66 ns 7/26/01 =1. 9 ns =2. 0 ns

Conclusion • delay ramps allow to reconstruct the entier pulse shape • important to study for a correct calibration • the timing problem is now fixed new ramps have to be taken calibration of all delay lines delay value for maximum response to be determined for all channels 7/26/01