Threshold Scan

Usage

The Threshold Scan is used to evaluate the threshold of the analog front-end of the ALPIDE Sensor. It configure the ALPIDE to have a threshold X. It then injects a charge C1 ranging from 0-50 DAC units to see the response in the pixel-matrix. The threshold of a pixel is determined by when it starts to respond to the injected charge. The result is presented for the entire pixel-matrix, where the average of the pixel thresholds are calculated.

How To

To run the test navigate to the test folder

$ cd tests

$ python3 threholdscan.py --board=BOARD --tctype=TCTYPE --chips=CHIPS

The test outputs a time-and-date.root file located in production_tests/results/

This file is automatically analyzed when you run the thresholdscan.py script. The analysis script is located in production_tests/plot/. A plot with the results from the test is provided and stored in production_tests/results/plots/. The plot will have the following name threshold_scan_chip_id_{}.png The result and classification is also provided in the terminal. The ALPIDE sensor can get GOLD, SILVER, BRONZE or NOK as a classification based on the result of the test.

The config file for the test is located in production_tests/config/. The DAC Settings section can be edited in order to alter the performance of the ALPIDE. It is mainly the following settings which are of interest for the test: VCASN, ITHR, IDB, VRESETD.