Difference between revisions of "LE algo"

Revision as of 09:50, 18 May 2011

• Page still under edit, incomplete

Results using Gerard's leading edge algo with CDC prototype, cosmics

• 50/50 mixed Ar, CO₂
• Recalibrated MFCs
• Outer plenum added to CDC prototype to prevent leaks
• New modified HVB
• 2050V
• Modified preamp4 (terminating resistors removed)
• Prototype tilted at 45^o to enclosing scintillators (which trigger daq)

The original algorithm is here algo code It takes 50 samples from the ADC data, convolutes them with the filter which I think is the inverse of the filter which the fADC uses when it digitises its input, optionally interpolates 4 extra points between each sample, and returns the first value above a predefined threshold.

Saturated event pics

Below: cosmics with new fADC, preamp4 (top) and newest modified preamp (below). Blue histograms are tracked hits, runtimes were not equal. The fADC range is 0-4096. These are histograms of the first maximum in ADC value for each event, pedestal has been subtracted, maximum must be above threshold. Threshold is pedestal mean + 5sigma. Pedestal mean was approx 100, sigma is 9-12.

Max amplitude histo for cosmics, new fADC, modified HVB, mixed 50/50 at 60 sccm 2050V

Max amplitude histo for cosmics, new fADC, modified HVB, modified preamp, mixed 50/50 at 60 sccm 2050V

Max amplitude histo for cosmics, new fADC, modified HVB, modified preamp, mixed 50/50 at 60 sccm 2050V

Below: threshold pedestal mean + 4sigma

Max amplitude histo for cosmics, new fADC, modified HVB, modified preamp, mixed 50/50 at 60 sccm 2050V

Below: 2100V (threshold pedestal mean + 5sigma)

Max amplitude histo for cosmics, new fADC, modified HVB, modified preamp, mixed 50/50 at 60 sccm 2100V

Earlier new fADC results are on this page: New_fADC_with_cosmics

Below: 55Fe spectra with preamp 4 and Struck ADCs set to half-range, 550mV

Max amplitude histo, 55Fe, 2050V, Struck fADC range 550mV

Max amplitude histo (x-axis expanded), 55Fe, 2050V, Struck fADC range 550mV

Integrated, 96ns, 55Fe, 2050V, Struck fADC range 550mV

Below: 55Fe spectra with newest preamp (preamp4 minus terminating resistors) and Struck ADCs set to full-range, 1.1V

Max amplitude histo, 55Fe, 2050V, Struck fADC range 1.1V

Max amplitude histo (x-axis expanded), 55Fe, 2050V, Struck fADC range 1.1V

Integrated, 96ns, 55Fe, 2050V, Struck fADC range 1.1V

Below: Scope pics with Fe55, preamp4 (left) and preamp5 (right) (preamp5=preamp4 minus terminating resistors), 2050V

Preamp4, Fe55, 2050V

Preamp5, Fe55, 2050V

Below: Scope pics with cosmics, preamp4 (left) and preamp5 (right) (preamp5=preamp4 minus terminating resistors), 2050V

Preamp4, cosmics, 2050V

Preamp5, cosmics, 2050V

Below: Pedestal, mean of samples 0-99 in groups of 100 events, preamp4 (left) and preamp5 (right) (preamp5=preamp4 minus terminating resistors), 2050V

Preamp4, pedestal: mean of samples 0-99 in groups of 100 events, 2050V

Preamp5, pedestal: mean of samples 0-99 in groups of 100 events, 2050V

Below: Pedestal standard deviation of samples 0-99 in groups of 100 events, preamp4 (left) and preamp5 (right) (preamp5=preamp4 minus terminating resistors), 2050V

Preamp4, pedestal: standard deviation of samples 0-99 in groups of 100 events, 2050V

Preamp5, pedestal: standard deviation of samples 0-99 in groups of 100 events, 2050V

Below: Max amplitude histograms fitted for ch6, required > 5 hits but no track, hit threshold is pedestal mean + 5sigma

Preamp4 max amplitude histo ch6 cosmics 2050V

Preamp5 max amplitude histo ch6 cosmics 2050V

Below: Residuals for ch23, 5+ hits, hit threshold is pedestal mean + 5sigma, added 8ns to fitted tzero

Preamp4 residuals ch23 cosmics 2050V

Preamp5 residuals ch23 cosmics 2050V

Below: Residuals for ch23 omitting ch23 from the track-fit, 5+ hits, hit threshold is pedestal mean + 5sigma, added 8ns to fitted tzero

Preamp4 residuals ch23 cosmics 2050V

Preamp5 residuals ch23 cosmics 2050V

Below: Event pictures - fADC values for 49k cosmics events, 2100V, 45degrees - to show that the preamp saturates before the fADC

Events ch22 cosmics 2100V

Events ch22 cosmics 2100V