Preamp Filter Card Testing Index -------------------------------------- Original Rev. 2-MAY-2008 Current Rev. 9-FEB-2009 This file is an index to the various files in this directory all of which are about the testing of the Preamp Filter cards, PFC-16. R034_E001_T102821_Adf0.pdf This shows the response of the filter section of the PFC-16 card to a step function input. The positive 10 mV step function was applied at the input of the filter section of Channel #16. The preamp section of this channel was disconnected from the circuit. Channels 28:31 are recording normal noise. R035_E001_T105712_Adf0.pdf This shows the response of the filter section of the PFC-16 card to a step function input. The positive 10 mV step function was applied at the input of the filter section of Channel #17. The preamp section of this channel was disconnected from the circuit. Channels 28:31 are recording normal noise. More information about the events from R034 and R035: I made this test on two different channels and collected 3 events from each channel. The data files are just ascii text files so you can look at them even with the web browser. Each data file has 2048 lines of data. Each line is just a decimal number in the range 0:1023 This was run with the ADF-2 card setup to give 400 counts of ADC output when there was 0.0 Volts coming into it. There is 198 nsec between ADC samples. The waveform starts about 1/4 of the way through the file. Note that the signal generator making the step was not synchronized with the 198 nsec sampling clock on the ADF-2 card. Thus from event to event the actual beginning of the step may move around by up to one ADC sample. A type "D" ADF-2 card was used for these tests. It has a nominal 5.5 Volts differential input to make a full scale swing of the ADC. The exact number is 5.317 mV per ADC count. In the data files you will see a peak swing to about 532 counts. This is 132 counts above its pedestal of 400 counts and thus the ADF-2 card saw an input of about 702 mV differential. The step was 10 mV. The differential gain of the Buffer stage (in its pass band) is 8.25 The gain of the First Stage Filter (in its pass band) is 5.0 The gain of the Second Stage Filter (in its pass band) is 4.7 The series termination of the cables between the PFC-16 and the ADF-2 card result in the ADF-2 card seeing 1/2 of the output from the PFC-16. Putting this all together means the a 10 mV sin wave going into the Buffer stage should result in the ADF-2 seeing a 970 mV signal (sin wave at a frequency in the middle of the band pass). At the input to the Buffer stage the sensitivity of the system is about 55 uV per ADC count and the pedestals are holding within one count. R039_E001_T162205_Adf0.pdf and R039_E002_T162213_Adf0.pdf These two events show a standard size test signal on Channel #15 and noise on Channels 12, 13, 14. The "standard" test signal that we have been using tries to look something like a middle induction plane signal with 5mm wire spacing and 5 mm plane spacing. What we use is one cycle of a 150 kHz sin wave. This signal starts at zero then swings negative for the negative 180 deg of the sin wave (charge coming towards the wire) then swings positive for the positive 180 deg of the sin wave (charge moving away from the wire) then returns to zero. 150 kHz has a 1/2 period of 3.33 usec the same as the drift time between planes at the standard 1.5 mm/usec drift velocity. The signal is scaled so that during each 1/2 cycle a total of 3.5 femto-Coulombs moves either into or out of the preamp. This is 22,000 electrons. It is my understanding that this is about how big the signal should be with 5 mm wire spacing and a track running parallel to the wire plane. To the extent that one cycle of a sin wave looks like the real current flow waveform on a TPC middle plane wire, and to the extent that 3.5 femto-Coulombs is the right size signal then the readout waveform shown in these plots and the signal to noise ratio in these plots should be what you see in the real detector. The data from these two events is in the ".dat" files with the same Run and Event numbers. These files use the same ASCII data file format as is used in the "Bo" event files. You can directly look at these files with a web browser or editor and "import" them into a spreadsheet or whatever. R049_E002_T163521_Adf0.pdf and R049_E002_T163521.dat This is an "event" from the 32 Channel Pulser that was built for the Bo DAQ System. The signals from this pulser are going through an adaptor and then into a BVDC card and then through 9 feet of 3M polyolefin twist and flat cable and then into a T962 PFC-16 card. The extra ringing in each pulse comes from channel to channel coupling in the 32 Channel Pulser itself, and not from the readout system. R001_E002_T191536_Adf0.pdf This event is from the first pulser run on T962 at PAB that used all T962 equipment in the DAQ system. The PFC-16 card was in the real T962 preamp box, powered by the T962 preamp supply, using a T962 Wiener crate, and a T962 Bit-3 card set, with the T962 DAQ computer. R241_E2_T110813.dat R241_E2_T110813_W50.pdf R242_E2_T111050.bin These files were recorded with DAQ-480. 96 channels were reading out when these files were made. You will see a block of 16 channels starting with channel 53 that have a pulse in them. The .dat file is the ASCII data file format just like in Bo's DAQ-96 system. The .pdf file is a plot of 32 channels starting with wire 50. The .bin file is in the binary data file format for DAQ-480. scope_pict_narrow_gaussian_step_response.tif run_490_event_002_ch_1.txt run_491_event_002_ch_0.txt 9-FEB-2009 These 3 files are from tests of the Narrow Gaussian filter on PFC-16 card SN #0. On this card channels #0 and #1 had the connection from the preamp output to the filter input broken and the input to the filter was connected to a terminator- attenuator. The input to this terminator-attenuator was the square wave output of the HP signal generator. The terminator-attenuator passed through about 0.096 of the signal from the HP generator. For the scope picture the scope was tied to one side of the PFC-16 card's output and the PFC-16 card was not plugged into the ADF-2 card, i.e. the output of the PFC-16 card was not loaded. The output of the HP generator was set to 35 mVpp (into 50 Ohms), square wave, 10 Hz. After the terminator-attenuator the actual input to the filter was about 3.37 mV. In the scope picture we see a peak filter output of about 320 mV. The DAQ-480 system was used to record two events with this step function input. This was done with the HP generator still setup as explained above. run_490_event_002_ch_1.txt signal from Ch #1 on the PFC-16 card SN #0 run_491_event_002_ch_0.txt signal from Ch #0 on the PFC-16 card SN #0 In these ascii format data files the peak of the filter's output is at about sample 275 i.e. about 1/8th of the way into the file. Details are on page 51 of notebook #10.