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Gain Curves. Jason for the SB Crew June 5, 2007. Raw 55 Fe Spectra. Start with 55 Fe spectrum from a MCA. Fit peak to gaussian. Calibration from a pulser turns channels into electrons. Mean of gaussian corresponds to signal from 109 electrons (in CF 4 ). Raw Curves.
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Gain Curves Jason for the SB Crew June 5, 2007
Raw 55Fe Spectra • Start with 55Fe spectrum from a MCA. • Fit peak to gaussian. • Calibration from a pulser turns channels into electrons. • Mean of gaussian corresponds to signal from 109 electrons (in CF4).
Raw Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • source rate: ~100 Hz
Raw Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • source rate: ~100 Hz
P/T Corrections • sealed volume in gain test box allows for easy P/T mapping. • in very good agreement with WIS. • Therefore, gain can be adjusted for P/T variations…
P/T Corrected Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • corrected for P/T !! • source rate: ~100 Hz
P/T Corrected Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • corrected for P/T !! • source rate: ~100 Hz
Gain Saturation Curve • Sample gain every two minutes for 14 hours. • Fit saturation curve to saturating exponential. • Gives the ability to extrapolate gain.
Completely Corrected Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • corrected for P/T !! • use extrapolated saturation curve to correct for time… • SB sees a factor of ~2 • source rate: ~100 Hz
Completely Corrected Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • corrected for P/T !! • use extrapolated saturation curve to correct for time… • SB sees a factor of ~2 • source rate: ~100 Hz
Completely Corrected Curves • Procedure: • 14 hour gain saturation curve • to fully charge up the stack • waited ~2 hours with voltage on • to verify stable gain • measured gain as a function of dV • corrected for P/T !! • use extrapolated saturation curve to correct for time… • source rate: ~100 Hz **note** the WIS data is from two different stacks… a gem was exchanged. --maybe not comparable.