Axes, bin indices & binned reductions

Steps that build delay/energy axes, assign each shot to a bin, and collapse per-shot data into a binned spectrum. Axis and index steps run first; the reduce_detector_* steps consume the indices they produce. See the step reference overview for the shape vocabulary.

Building axes and bin indices

time_binning

Compute per-shot delays from laser timing keys and lay down delay bins.

• Reads: lxt_key, fast_delay_key, tt_correction_key — each (shots,). Uses whichever exist.
• Writes: delays (shots,), time_bins, time_bins_centered, timing_bin_indices (shots,).
• Parameters:

name	default	description
bins	required	"auto", an explicit list of centers, or [min, max, num_points]
lxt_key	"lxt_ttc"	long-delay stage key; null to skip
fast_delay_key	"encoder"	fast-stage key
tt_correction_key	"time_tool_correction"	time-tool jitter correction key
resolution	50e-15	bin width in seconds for bins: auto

- step: time_binning
  bins: [-1e-12, 5e-12, 25]

make_ccm_axis

Build incident-energy (CCM) bin edges and centers for an XAS scan.

• Reads: ccm_key (shots,) when energies: auto.
• Writes: ccm_bins — n+1 edges; ccm_energies — n centers.
• Parameters:

name	default	description
energies	"auto"	"auto", explicit list, or [min, max, num_points]
ccm_key	"ccm"	per-shot incident-energy key
resolution	0.001	bin width (keV) for energies: auto

- step: make_ccm_axis
  energies: [7.10, 7.15, 51]

ccm_binning

Assign each shot to a CCM energy bin.

• Reads: ccm_key (shots,), ccm_bins_key (edges).
• Writes: ccm_bin_indices (shots,).
• Parameters:

name	default	description
ccm_key	"ccm"	per-shot incident-energy key
ccm_bins_key	"ccm_bins"	edges produced by make_ccm_axis

- step: ccm_binning
  ccm_key: ccm
  ccm_bins_key: ccm_bins

bin_uniques

Bin an arbitrary scan variable by its unique values (one bin per value).

• Reads: scan variable on (shots,).
• Writes: scanvar_indices (shots,), scanvar_bins (unique values).
• Parameters:

name	default	description
on	required	per-shot scan variable to bin

- step: bin_uniques
  on: sample_temperature

make_energy_axis

Convert pixel index to emission energy from von Hamos crystal geometry.

• Reads: detector_key (to read pixel count) or n_pixels directly.
• Writes: <name>_energy (pixels,).
• Parameters:

name	default	description
crystal_detector_distance	required	crystal-to-detector distance A (mm)
crystal_radius	required	crystal bend radius R (mm)
d_spacing	required	crystal d-spacing (angstrom)
detector_key	None	key to read pixel count from
n_pixels	None	pixel count; overrides detector_key
mm_per_pixel	0.05	pixel pitch (mm)
name	"xes"	output prefix, so the axis is <name>_energy

- step: make_energy_axis
  detector_key: epix
  crystal_detector_distance: 100.0
  crystal_radius: 500.0
  d_spacing: 1.6375
  name: xes

Binned reductions

Each reduction sums per-shot data into its bins. Pass average: True to divide by the per-bin count; the raw count is always written as <on>_..._bincount for downstream normalization or cross-run combination.

reduce_detector_temporal

Bin a per-shot spectrum along delay.

• Reads: detector on — 1D (shots,) or 2D (shots, pixels); plus timing_bin_indices and time_bins.
• Writes: <on>_time_binned (n_time_bins[, pixels]), <on>_bincount.
• Parameters:

name	default	description
on	required	detector key
timing_bin_key	"timing_bin_indices"	bin-index attribute
average	False	divide each bin by its shot count

- step: reduce_detector_temporal
  on: epix_ROI_1_simultaneous_laser
  average: true

reduce_detector_ccm

Bin a per-shot spectrum along incident energy.

• Reads: detector on — 1D/2D/3D; plus ccm_bin_indices.
• Writes: <on>_energy_binned (n_energy[, ...]), <on>_energy_bincount.
• Parameters:

name	default	description
on	required	detector key
ccm_bin_key	"ccm_bin_indices"	bin-index attribute
average	False	divide each bin by its shot count

- step: reduce_detector_ccm
  on: epix_ROI_1
  average: true

reduce_detector_ccm_temporal

Bin a per-shot spectrum along both delay and incident energy (2D map).

• Reads: detector on — 1D/2D; plus timing_bin_indices and ccm_bin_indices.
• Writes: <on>_time_energy_binned (n_time, n_energy[, pixels]), <on>_time_energy_bincount.
• Parameters:

name	default	description
on	required	detector key
timing_bin_key	"timing_bin_indices"	delay bin-index attribute
ccm_bin_key	"ccm_bin_indices"	energy bin-index attribute
average	False	divide each bin by its shot count

- step: reduce_detector_ccm_temporal
  on: epix_ROI_1
  average: true