LSTCam low-level data analysis

During our LST low-level data calibration workshop at TU Dortmund, we collected a list of calibration runs we think are needed in order to perform the calibration. We would like to have these runs taken in the lab, so that we can use them during the development of the calibration algorithms and the software. Some of them might be necessary to be performed also later during data taking.

1. Offset calibration / pedestal run (as MAGIC takes them):¶

• No input signal.
• These pedestal runs should be taken with the same ROI as the future physics runs will have.
• Stop cells should be uniformly distributed.
• Time between triggers should be exponentially distributed, as nature does it.
• #events: O(800k events)
• Rate: once with 1kHz and once with 10kHz (expectation value of the exponential distribution)
• Stable and known board temperature is desirable.

2. Set of Gain/Linearity measurement run:¶

• 5 different DC input voltages in (up to 80%).
• So we can measure the linear response of all caps
• Be sure that no cell is saturating.
• Same modes as no 1.

3. Time calibration run:¶

• A periodic signal of high enough amplitude (say 80% again?) and about 40MHz frequency (sampling with 2GHz). Not in phase with DRS4 reference clock.
• RoI: data_RoI(=100?), 1024 or 4096 if possible.
• We want to see O(100k) calibration signal periods, so
• #events: 50k@RoI=100, 5k@RoI=1024, 1.2k@RoI=4096

Current status of the software development¶

We received some first data from the mini-camera tests supplied by Takayuki.
A first reader has been implemented (for testing purposes this is for now done in python).

We also reviewed currently used DRS4 calibration algorithms from MAGIC and FACT.

Based on the mini camera data pedestal measurements we calculated (simplified) offset constants.

We started to implement a macro for checking the cross-talk.

Also, a first draft for a reader for the mini-camera data format based on the streams software framework is ready.