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Entry  Fri Sep 2 21:16:45 2016, rana, Update, Electronics, Satellite Amplifier 
    Reply  Mon Sep 5 21:05:06 2016, rana, Update, Electronics, Satellite Amplifier osempd.pdf
       Reply  Tue Sep 6 00:14:14 2016, gautam, Update, Electronics, Satellite Amplifier osempdComparison.pdf
          Reply  Mon Sep 19 13:25:03 2016, Teng, Update, Electronics, Satellite Amplifier Ele_measurement.pngEle_noise.png
             Reply  Mon Sep 19 13:57:21 2016, rana, Update, General, never post EPS files in the ELOG. Ever. 
Message ID: 12471     Entry time: Tue Sep 6 00:14:14 2016     In reply to: 12470     Reply to this: 12505
Author: gautam 
Type: Update 
Category: Electronics 
Subject: Satellite Amplifier 

 

If we have some data with one of the optics clamped and the open light hitting the PD, or with the OSEMs removed and sitting on the table, that would be useful for evaluating the end-to-end noise of the OSEM circuit. It seems like we probably have that due to the vent work, so please post the times here if you have them.

The ETMX OSEMs have been attached to its Satellite box and plugged in for the last 10 days or so, with the PD exposed to the unobstructed LED. I pulled the spectrum of one of the sensors (mean detrended, I assume this takes care of removing the DC value?). The DQed channels claim to record um (the raw ADC counts are multiplied by a conversion factor of 0.36). For comparison, re-converted the y-axis for the measured curve to counts, and multiplied the total noise curve from the LISO simulation by a factor of 3267.8cts/V (2^16cts/20V) so the Y axis is noise in units of counts/rtHz. At 1Hz, there is more than an order of magnitude difference between the simulation and the measurement which makes me suspect my y-axis conversion, but I think I've done this correctly. Can such a large discrepancy be solely due to thick film resistors?

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