Evidence for phonon hardening in laser excited gold using x-ray diffraction at a hard x-ray free electron laser -- LCLS LW5919

This dataset contains the raw images used in the analysis for the manuscript entitles "Evidence for phonon hardening in laser excited gold using x-ray diffraction (XRD) at a hard x-ray free electron laser". The experiment was performed at the Matter in Extreme Conditions (MEC) endstation at the Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory. We are including the raw images for the X-ray diffraction pattern and the images collected using the timetool available at MEC. Further details can be found in the Materials and Methods of the main manuscript.

Description of the data and file structure

We are uploading a folder containing the XRD images named "XRD_dataset" and one folder with the timetool images named "timetool_dataset". Within each folder, we have separated the data in different sub-folders for each run collected during the experiment. Each run corresponds to a nominal time delay between the X-ray pulse and the optical laser pulse. Within each run folder, the images are numbered for each X-ray pulse used.

The timetool images and the XRD images are collected simultaneously. An XRD image corresponds to a unique timetool image. For instance "XRD_dataset/r295/XRD_r295_0.tif" corresponds to "timetool_dataset/r295/TT_r295_0.tif".

We also include an image of the focal spot for r256. This run was used to define t = 0 ps between the optical laser pulse and the X-ray pulse. More details are found in the supplementary information.

For the data presented in the manuscript, we have filtered the images within each run based on the signal on the timetool. When the timetool singal could not been seen we discarded this X-ray pulse since we could not obtain a precise timing.

The timetool signal is stronger for r256 because the thickness of SiN was larger than the other runs.

Description of the logbook sheet

• Column "Run Number":

Number of folder corresponding to the same experimental conditions

• Column "Change timing based position of translation stage of timetool (MEC:LAS:MMN:19.RBV) [mm]"

When changing the time delay between the optical laser pulse and the X-ray pulse, timing on the timetool needs to be compensated by a delay stage. The values in this column report the position of the delay stage.

• Column "Change relative timing based on delay stage compared to run 256 (reference for defining t = 0ps)"

This column converts the position of the previous column into a time delay. The reference is taken to be the position of r256 which define t = 0 ps.

• Column "Laser triggering time (LAS:FS6:VIT:FS_TGT_TIME) [ns]"

These values correspond to the triggering time of the short pulse laser system.

• Column "Change relative timing on laser triggering compared to r256 Vitara [ps]"

These values calculate the triggering time from the previous column into a time delay using r256 as a reference.

• Column "Comments"

Comments for each run. The numerical values correspond to the targeted time delay for each run.

Column E corresponds to the actual time delay of the run. These values are within 0.1 ps of the targeted time delay. To reach the timing accuracy described in the main manuscript we need to use the time tool. However, as seen in column C, the time delay on the time tool doesn't match the values in column E. If we use the time tool with the pixel position found for t = 0 ps using r256 (analysis in Materials and Methods), then we would measure a time delay that is offset by the value of C-E. This offset needs to be compensated.

For run 288, only X-ray pulses were present. The optical laser was not fired so no values for columns B to E are present. We use "NA" to represent this.