Time-of-Flight (ToF)

The Time-of-Flight (ToF) module is designed to calculate the time delay between when a particle is detected by a pixel in the detector and a reference time signal provided by one of the Time-to-Digital Converters (TDCs).

Key Features

  • Automatic Time Calculations: Automatically computes the time-of-flight for each detected pixel hit relative to a selected reference signal.

  • Multiple Reference Options: Offers support for different Time-to-Digital Converter (TDC) references, allowing flexibility in experimental setups.

  • Easy Configuration: The ToF feature can be activated with a single configuration setting, simplifying the setup process.

Algorithm Overview

The ToF module calculates the time delay for detected events through the following steps:

  1. Reference Selection: The user selects a TDC reference via the Command Line Interface (CLI) or the YAML configuration file. This reference provides the baseline time from which all ToF calculations will be derived.

  2. Timestamp Sorting: Luna reads the timestamp for each detected signal event (pixel hit) and reference event (TDC). These events are sorted into a single queue based on their timestamps to ensure correct chronological order.

  3. ToF Calculation: The ToF for each pixel hit is calculated using the selected reference time. The algorithm processes the queue as follows:

    • Pixel Hit Event: If the event is a pixel hit, the ToF is computed using the current reference time. The ToF is given by:

      \[\text{ToF} = \text{ToA}_{\text{Pixel}} - \text{TDC}_{\text{Reference}}\]

      where:

      • \(\text{ToA}_{\text{Pixel}}\) is the Time of Arrival (ToA) of the pixel hit.

      • \(\text{TDC}_{\text{Reference}}\) is the timestamp from the current TDC reference event.

    • TDC Event: If the event is a TDC event, the current reference time is updated. All subsequent pixel hits will use this new reference time for their ToF calculation.

Performance

The ToF module is designed to operate efficiently with minimal impact on overall system performance. It processes timing data without applying timewalk corrections.