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FCal Energy Scale Predictions J.Rutherfoord 9 June 2003. Overview. The signal path Signal pulses Calibration pulses The inputs and uncertanities Summary predictions. Points of Reflection. At interconnect (but neglect this) Off distributed Ohmic resistance of cable At coupling capacitor
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Overview • The signal path • Signal pulses • Calibration pulses • The inputs and uncertanities • Summary predictions J. Rutherfoord
Points of Reflection • At interconnect (but neglect this) • Off distributed Ohmic resistance of cable • At coupling capacitor • At transformer (but neglect this except for sick channels) • At vacuum and pedestal cables • At imperfect matching of preamp input impedance to cable • At many other smaller (negligible?) locations J. Rutherfoord
FCal Electronics Chain 1 May 2003 1 4 9 11 12 5 8 16 14 15 10 13 Vacuum Cable and Pedestal Cable FCal Module Summing Board Front End Board Calib Pulser Preamp Shaper Pipeline Gain Offset ADC J. Rutherfoord
Signal Limits • Pipeline limits signal size (2nd lobe) • Switch from Shaper High Gain to Medium Gain • At 130, 260, and 300 GeV respectively for FCal1, FCal2, and FCal3 J. Rutherfoord
Triangle shape • In principle, many things modify the shape of the triangle pulse. But none are significant. • The significant parameters are • initial current • the drift time J. Rutherfoord
out 10 H (1.8 H) 50 1.53 A/CalDAC 14 Channels in all; 4 shown in Injection R 695 … + preamp cable Calibration Pulser System J. Rutherfoord
Courtesy of Adam and Petr J. Rutherfoord
Table of FCal Signal Parameters J. Rutherfoord
Summary Prediction • Signal (on the electron scale) and noise, both at High Gain Signal Noise (ADC Counts/GeV) (ADC Counts) FCal1 12.8 2.9 FCal2 6.5 2.9 FCal3 5.8 2.9 J. Rutherfoord