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Obtaining S-curves for all pixels of TDCPix matrix

The second version of plotting S-curve for all pixels. This algorithm is faster and more effective. This version is stable.

The executable is .../TDCPixReadOut/Tools/bin/calibration2.

Although it is literally called calibration2, in reality it is just a first step - plotting S-curve for all pixels.

Before using this app it is recommended to launch from the same directory:

./matrix_check <Qcal> <Vth> <Acc>

where Acc is the deviation value in % from which we consider pixel to be bad. It allows for excluding problematic pixels that makes software more stable.

Usage of the app

./calibration2 <starting_row> <Qcal> [<range> <step>]

where

starting_row = 0..44 - address of the row from what to start the algorithm.

Qcal = int - charge injection level in Voltage steps. The range is 0 - 255. One voltage step corresponds injection charge step of 0.0436 fC (see TDCPix manual s. 3.11 for more info).

range is an optional argument 30 by default. Responsible for S-curve plotting range.

step is an optional argument 2 by default. This is an increment for S-curve plotting.

./calibration2 0 40

This command launches scan for getting s-curve for all pixels with injected charge of 40 * 0.0436 fC = 1.744 fC.

Code

Code structure is slightly different from version 1.

Main loop.

Step 1. For each pixel in a certain row find optimal Vth range: Coarse scan with increment dVt of 10 steps. The first threshold voltage where number of received hits equals 0 is set to be ending point. Start point is <range> units lower.

Step 2. For each pixel in a row the code gives s-curve in obtained optimal range.

Step 3. Row number++

Step 4. Subcolumn++

Output

The output is a set of text files - two for each row: arrays of Vth for every column and arrays of numbers of received hits. Combining these two files it is possible to plot S-curve for each pixel in a chosen row. Also the program delivers output.root file in Run directory that contains s-curves in TGraph for all pixels and TH2D for all columns.