Supporting Information for "First Results of Terrestrial Gamma-ray Flash observations by Insight-HXMT"

The compressed file contains data for 282 HXMT Terrestrial Gamma-ray Flashes (TGFs), spanning from T0-1 second to T0+1 second. Below is a description of the data format included in the file.

[HXMT 1K Science Data Description]

1. The "Time" column represents the Mission Elapsed Time (MET) in seconds for HXMT, starting from 2012-01-01T00:00:00.

2. The "Det_ID" column indicates the detector index for the 18 HXMT/HE NaI/CsI detectors, ranging from 00 to 17.

3. The "Channel" column refers to the energy channel for HXMT/HE NaI/CsI detectors, which spans from 0 to 255. Data filtering often uses "Channel>30" to exclude lower energy events.

4. The "Pulse_Width" column measures the pulse width of the detector signal in milliseconds. For HXMT/HE data, a Pulse Width value of N translates to N/48 ms. To filter the data, "Pulse_Width>75" is commonly used.

5. The "ACD" column presents data from the anticoincidence detectors of the HXMT/HE Anti-Coincidence Detector (ACD). This data consists of an array of 18 boolean values, each corresponding to a specific ACD. For instance, if the first value in the array is 1, it indicates that the event was simultaneously detected by ACD-01; conversely, a 0 in the second position signifies that ACD-02 did not detect the event at the same time. Typically, events detected by any ACD are excluded from data analysis. Conversely, events are included in data analysis when all ACD values are 0.

6. The "Event_Type" column describes the operational modes of the detector: 0 for normal-gain mode and 1 for low-gain mode.

Details on the NaI/CsI and ACD detector installation positions and the relationship between energy and channel for both normal-gain and low-gain modes can be found in Song et al. 2022.