Re: FDC/CDC ASIC meeting minutes

[Yves Van Haarlem <yvhaarle@ernest.phys.cmu.edu>]

Hi Gerard,

>>> p.s. Are the histograms (I presume in a narrow time window) centered on 
>>> the
>>> peak time of the pulse in each of the 6 cases independently, or at fixed
>>> time, not therefore picking up the peak amplitude? I presume/hope you have
>>> done the former.
>> I do not remember the time window that was set (it was not very narrow)
>> but the scope displays the measurment every time it measures an amplitude
>> and that looked correct.
>
> Your answer confuses me... Are these histograms in all cases an accurate 
> representation of the peak amplitude? I was assuming these are just 
> histograms of the waveform crossing a box, and that the box was set to be at 
> the observed typical time of the peak... Maybe I just have that wrong and the 
> scope is here histogramming the measured peak amplitude where that 
> measurement happens independently on each acquisition. Please clarify this.


This measurement was done with the LeCroy WaveRunner oscilloscope. You set 
a measurement (the amplitude in this case). For every trigger fired it 
measures the amplitudes and shows on the scope how it (baseline and peak) 
-> that looked good. Then you can dump that measurent into a 
histogram. So every trigger adds one event in the histogram.


Cheers,
 	Yves